Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2014; 20(48): 18104-18120
Published online Dec 28, 2014. doi: 10.3748/wjg.v20.i48.18104
New trends in colorectal surgery: Single port and natural orifice techniques
Ronald Daher, Elie Chouillard, Yves Panis
Ronald Daher, Elie Chouillard, Department of General and Digestive Surgery, Poissy/Saint-Germain Medical Center, 78300 Poissy, France
Yves Panis, Department of Colorectal Surgery, Beaujon Hospital, Assistance Publique Hopitaux de Paris, University Denis Diderot (Paris VII), 75013 Clichy, France
Author contributions: Daher R and Chouillard E designed research, performed research; Chouillard E and Panis Y contributed new reagents or analytic tools; Daher R, Chouillard E and Panis Y analyzed data; Daher R and Chouillard E wrote the paper.
Correspondence to: Elie Chouillard, MD, Department of General and Digestive Surgery, Poissy/Saint-Germain Medical Center, 10 rue du Champ Gaillard, 78300 Poissy, France.
Telephone: +33-1-39275170 Fax: +33-1-39274873
Received: March 20, 2014
Revised: July 28, 2014
Accepted: October 15, 2014
Published online: December 28, 2014


Single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES) have rapidly gained pace worldwide, potentially replacing conventional laparoscopic surgery (CLS) as the preferred colorectal surgery technique. Currently available data mainly consist of retrospective series analyzed in four meta-analyses. Despite conflicting results and lack of an objective comparison, SILS appears to offer cosmetic advantages over CLS. However, due to conflicting results and marked heterogeneity, present data fail to show significant differences in terms of operative time, postoperative morbidity profiles, port-site complications rates, oncological appropriateness, duration of hospitalization or cost when comparing SILS with conventional laparoscopy for colorectal procedures. The application of “pure” NOTES in humans remains limited to case reports because of unresolved issues concerning the ideal access site, distant organ reach, spatial orientation and viscera closure. Alternatively, minilaparoscopy-assisted natural orifice surgery techniques are being developed. The transanal “down-to-up” total mesorectum excision has been derived for transanal endoscopic microsurgery (TEM) and represents the most encouraging NOTES-derived technique. Preliminary experiences demonstrate good oncological and functional short-term outcomes. Large-scale randomized controlled trials are now mandatory to confirm the long-term SILS results and validate transanal TEM for the application of NOTES in humans.

Key Words: Surgery, Colon, Rectum, Cancer, Laparoscopy, Single-port, Natural orifice transluminal endoscopic surgery

Core tip: Despite lack of irrevocable proofs and unresolved technical issues, single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES) became inevitable options in today’s colorectal surgery armamentarium. In comparison to conventional laparoscopic surgery, colorectal SILS offers a cosmetic advantage with no compromise of surgical morbidity, oncological appropriateness or increased cost. The “down-to-up” total mesorectum excision appears as the most encouraging NOTES-related technique for clinical application in humans. It further offers potential benefits in functional and oncological outcomes. Well-designed randomised studies are now essential to validate the long-term results of these novel techniques.

Citation: Daher R, Chouillard E, Panis Y. New trends in colorectal surgery: Single port and natural orifice techniques. World J Gastroenterol 2014; 20(48): 18104-18120

Laparoscopic colorectal surgery (LCS) has been confirmed as a safe and equivalent alternative to open surgery in the management of benign and malignant colonic diseases. Compared with open surgery, LCS reduces postoperative pain and duration of ileus, improves respiratory function, accelerates postoperative recovery, shortens hospital stay and enhances cosmesis[1-5]. Moreover, prospective randomized trials have demonstrated similar oncologic outcomes for LCS compared with open surgery in colon cancer patients[6-11]. In recent studies, laparoscopic resection for rectal cancer resulted in fewer postoperative complications[12-14] without compromising the oncological outcome[13,15].

LCS requires the usage of multiple ports, with each one representing a potential risk of hemorrhage, intraperitoneal organ injury, postoperative pain and herniation[16,17]. When laparoscopic surgery is intended for organ resection, as in colorectal surgery, a larger incision is required for specimen retrieval; this constitutes the major cause of morbidity in terms of pain, surgical site infection and herniation[18]. In a prospective study, the Pfannenstiel’s incision used for specimen retrieval led to unsatisfactory cosmetic results in 40% of patients[19]. Dedicated questionnaires have recently demonstrated increasing patient interest in cosmesis, emphasizing their preference for more minimally invasive options compared with standard laparoscopy[20,21].

In this overwhelming tendency towards minimally invasive surgery, the ultimate goal would be to perform “scarless surgery” with similar safety profiles, efficacy and long-term outcomes as the standard laparoscopic surgery. Natural orifice transluminal endoscopic surgery (NOTES) is the ideal illustration of possible achievement of this objective, providing a scar-free surgery with the abolishment of incision-related complications, postoperative pain and adhesions[22]. Since its first description in 2004[23], NOTES has continuously gained interest, as illustrated by the increasing number of publications[24]. With less than 10% of total surgeries using NOTES[24], colorectal procedures remain in the early stages of development and are mainly performed in cadaver and animal studies[25]. Applications of this surgery in humans remain limited. Difficulties related to the access site are still under evaluation and remain unresolved[26-29]. Other limitations include available instruments, working angles and specimen extraction[30-32]. Currently, in the field of colorectal surgery, NOTES is mostly performed under laparoscopy assistance, designated as “hydrid” NOTES[33]. However, the transanal endoscopic microsurgery (TEM) initially described by Buess et al[34] more than twenty years ago has inspired a novel approach to rectal cancer surgery based on a transanal, down-to-up approach to the mesorectum. This undoubtedly represents the most encouraging NOTES-related technique[35-39].

On the other hand, primarily driven by the increasing experience in LCS, progression towards single incision laparoscopic surgery (SILS) was natural, logical and feasible[40,41,51]. In SILS, all incisions are concentrated within a single location, typically at the umbilicus, a natural embryologic scar or occasionally at the planned site of a stoma. SILS advantages have been claimed to extend beyond cosmesis. Compared with LCS, further reduction of parietal incisions and surgical stress are hypothesized to correlate with lower postoperative pain, fewer port site complications, a better morbidity profile, shorter hospital stay and reduced cost while also providing a better cosmetic result[42,43]. Thus, short-term outcomes are supposed to improve while the safety and satisfaction criteria of the patients are met[20,44]. With relatively minor changes to existing laparoscopic techniques, all colorectal procedures have been successfully performed with the SILS technique[45,46]. The worldwide popularity of this attractive technique has rapidly grown, as proven by the drastic increase in the number of publications over the past 3 years[47]. Lately, numerous studies have aimed to demonstrate the real benefits of SILS over conventional laparoscopic surgery (CLS) regarding short-term outcomes and appropriateness for oncological resections. However, conclusive advantages and long-term results need to be confirmed by large-scale, randomized controlled trials (RCTs).

In this study, we reviewed the current world literature regarding these novel colorectal techniques. After a short summary of the historical background, we will focus on the principal results of their applications in humans, paying special attention to comparison with CLS. Technical challenges and fields of future development will also be discussed.


A systematic review of the published literature on colorectal SILS and NOTES was undertaken. The search was performed in October 2013 using PubMed, MEDLINE and the Cochrane Central Register of Controlled Trials. RCTs were recorded from the official web site . The following search terms were used: colorectal, colon, colectomy, rectum, proctectomy, total mesorectum excision, NOTES, NOSE, SILS, minimally invasive surgery and single port/trocar. Articles written in English or French were included irrespective of study type or publication status. A manual search of the reference lists of relevant papers was also performed to identify additional trials. Full-text reprints of all potentially appropriate articles were reviewed. The two reviewers separately classified the available articles into SILS, NOTES, comparative studies and future development. Hybrid techniques and non-human studies were included as appropriate for further discussion. Duplicate publications and those not written in English were excluded. The following information was extracted from each study concerning SILS: authors, year of publication, study population characteristics, study design, inclusion and exclusion criteria, number of benign and malignant cases, performed procedures, oncological results, long-term follow-up, postoperative morbidity, postoperative length of hospital stay and cost. NOTES-related articles were scrupulously reviewed for organ-access site, performed procedures, used techniques, surgical outcome and oncological appropriateness.


SILS was first reported in 1992 by Pelosi et al[48] as a transumbilical approach for appendectomy in a pediatric series and supracervical hysterectomy with bilateral salpingo-oophorectomy[18]. In 1997, Navarra et al[49] realized the first single-incision transumbilical cholecystectomy. This procedure was followed by the first single-port appendicectomy in 1998[50]. The first reports on colorectal resections through a transumbilical single-port access site were published in 2008[40,51] as a radical right hemicolectomy for polyp with extracorporeal ileocolic anastomosis. After initial experimental modeling[52], Bucher et al[41] realized the first transumbilical SILS sigmoidectomy for benign disease in humans. Progressively, more complex colorectal procedures have been successfully performed, such as anterior rectal resection, conventional proctocolectomy and total proctocolectomy with ileal pouch anal anastomosis[42,53-55]. Recently, in a large prospective series, Vestweber et al[45] demonstrated that SILS was suitable for all colorectal surgeries for benign and malignant diseases.

NOTES was first reported by Kalloo et al[23] in 2004 as a transgastric diagnostic peritoneoscopy. Within a year, the first human transgastric appendicectomy was presented at the Annual Conference of the Society of Gastrointestinal Endoscopy of India[56]. Aiming to encourage NOTES research and outline the areas of human application, the collaborative Natural Orifice Surgery Consortium For Assessment And Research (NOSCAR) was created from the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the American Society for Gastrointestinal Endoscopy (ASGE)[57]. Following the creation of this consortium, many experiments on porcine models were performed, such as endoscopic gastrojejunal anastomoses[58], transgastric splenectomy[59], transgastric cholecystectomy[60], transgastric abdominal exploration and pelvic organ resection[61]. In 2007, the first successful NOTES in humans was described: cholecystectomy through transgastric[62] and transvaginal routes[63].


The currently available data are mainly comprised of non-randomized, retrospective case series and fail to show formal superiority of SILS over CLS. Constant calls for RCTs[46,64-79] outline the urge for consistent data comparing these two techniques. However, since the earliest descriptive series, colorectal procedures were found to be safely performed under SILS[42,65,71,80]. It is surprising that the feasibility of the procedure has been the sole unchallenged conclusion[53,68,69,73-75,81,82], as if SILS was an intuitive, natural progression of CLS. Presently, SILS stands as an irrefutable alternative to colorectal CLS and merits scrupulous attention.

Heterogeneous reports indicate increased, equal or even decreased[75,83] operative time in SILS compared with CLS. However, most retrospective studies did not report any differences between SILS and CLS[68,69,74,78,82,84-92]. Conversely, four additional reports revealed a significant increase in operating times[77,93-95]. With prospectively collected data, Kim et al[77] clarified that operative time in SILS was significantly increased compared with CLS irrespective of the performed procedures (i.e., right or left colectomy, rectal resection). Nevertheless, operative time decreases with accumulating experience[67,93,96], and the fiftieth case is considered the time-point when SILS becomes fully efficient[77]. The gap between accumulated experiences in CLS and early performances of SILS may explain the operative time differences observed in the initial series[65]. In fact, three recent meta-analyses failed to show a significant difference in operative times between CLS and colorectal SILS[66,70,79].

Despite contradictory results[97,98], the hypothesized reduction of postoperative pain in SILS has been extrapolated from studies on cholecystectomy[99]. Compared with LCS, the reported results on postoperative pain after colorectal SILS are equivocal. Some studies favor SILS[77,86], whereas others favor CLS[68,74,82]; no significant differences are in reported in the remaining studies[69,89,100]. This disparity might be attributed to different scoring methods [i.e., number of doses[68], frequency of administration[74,77,91], visual analogue scale (VAS)[89,91,100,101], maximal pain score[74]] or types of analgesia (i.e., epidural[68,78,89,102,103], Demerol equivalents[69]). Kim et al[77] identified a significant reduction in narcotic frequency administration, whereas three comparative studies demonstrated a significant decrease in postoperative pain on the first[86,91,101] and second postoperative day[86,91]. Additionally, Vasilakis et al[91] concluded the advantage of SILS in reducing immediate postoperative pain when patients were evaluated in the recovery room. The mean VAS score, doses of painkillers and time spent before transfer were significantly reduced in the SILS group patients compared with those of the CLS group patients. This finding could be related to the reduction in wall trauma by the SILS techniques. Conversely, Lu et al[82] stated that VAS scores were significantly increased in SILS colectomy patients compared with LCS patients (3.07 vs 2.41, respectively, P < 0.001). Despite the fact that the reduction of postoperative pain was one of the main arguments for the application of SILS in colorectal surgery, only one RCT has examined this topic[104]. This study reported a lower median pain score in SILS patients compared with the CLS group but no difference in total morphine usage, albeit on a small number of patients. The only meta-analysis addressing this issue failed to find any significant differences between colorectal SILS and CLS[70]. Authors insisted on the inadequacy of existing data for homogeneous comparison and valid conclusions with respect to the inherent biases of retrospective studies and a lack of standardization in surgical techniques, analgesia protocols and pain assessment.

Overall, early postoperative complications after colorectal SILS occur in 9% to 31.5% of patients[45,47,64,74-77,79,84,105]. Severe complications (Clavien grade III and IV[106]) occur in 3.2% to 9.6% of cases[64,77,78], mainly including deep vein thrombosis, bleeding (1.2% to 1.7%)[64,105] and leakage (0% to 6.7%)[47,64,77,86,101]. Occurring in 1.6% to 4% of cases, ileus remains the most frequent minor complication[47,64,76,96,105]. In a series of consecutive unselected patients, Osborne et al[75] reported significantly increased rates of anastomotic bleeding and urinary retention when high anterior resection is performed using SILS techniques compared with CLS. Bleeding and transfusion requirements after colorectal resection are typically comparable between SILS and CLS[68,77,82,84,86,89,91-93]. Ramos-Valadez et al[90] observed an increase in bleeding with CLS; however, the difference was not clinically significant given that transfusion was not required for any patient. Globally, all available comparative studies precluded any significant difference in complication or morbidity rates between these techniques[68,69,74,77,82,84,86-90,93,94,100]. Three meta-analyses[66,70,79] confirmed that the safety profile was comparable despite significant heterogeneity and inherent selection bias in the study design.

Intraperitoneal organ lesions under SILS techniques are reported in less than 1% of the cases[72,77,85,101,105]. It is worth noting that available data clarify whether the blind angles encountered in SILS techniques increase the risk of organ injury when compared with CLS. To demonstrate a significant difference for such a low rate, the comparison would require a large-scale study, comparable to what was needed for the assessment of bile duct injury after open vs laparoscopic cholecystectomy[107]. The reduction of peritoneal adhesions and subsequent bowel obstruction was among the claimed advantages of SILS, but there are no long-term studies so far that confirm this hypothesis.

Although rare, port site complications after laparoscopy include infection, bleeding and delayed hernia. Because complications are related to the increased number of ports[108], SILS was hypothesized to decrease these risks[16,66]. After a follow-up of 15 mo, umbilical incisional hernias have been reported in 4% of colorectal SILS patients[96]. However, this rate averages 0% to 1% in most studies[45,101]. Colorectal SILS are frequently performed through an umbilical incision, which is further enlarged for specimen retrieval. These facts have been specifically associated with an increased risk of trocar site hernia in large retrospective[109] and prospective[18] studies. However, no difference was found in trocar site hernia rates (0.6%) when comparing conventional gastrectomy with single-port laparoscopic sleeve gastrectomy[110], which is comparable to colorectal SILS for parietal incision placement and enlargement. We consider that parietal incisions in SILS are easier to close than those made in conventional laparoscopy. When closing the incision, the surgeon should better conceive SILS as a minilaparotomy than an enlarged laparoscopy and apply a careful running suture instead of an approximate wide stitch. Early infection is reported in 2.5% to 10% of cases[45,47,64,78,84-86,96,100,101], and SILS does not appear to alter this risk compared with CLS[46,86,91,100,101]. Wound bleeding and hematoma rates are seldom reported in the literature; when reported, these rates vary from 1.2% to 5.0%[45,64,90]. In a cohort study including 1142 SILS procedures, Weiss et al[111] reported comparable parietal complication rates with the exception of infection, which appears to be more frequent in colorectal procedures (2.5% vs 1.05%). Despite the fact that reduced port-site complications was one of the most defended arguments in favor of SILS, it is surprising that no consistent data confirm this hypothesis to date.

To assess the oncological appropriateness of SILS for colorectal cancer, numerous studies compared surgical margins with those found in CLS. No significant differences were detected between the two groups[68,69,74,77,82,84,90,92,93]. This finding was supported by the meta-analysis conducted by Zhou et al[66], stating that SILS was equivalent to CLS for R0 resection and specimen length. The number of retrieved lymph nodes was also equivalent between the two techniques in most studies[68,69,74,77,78,84-86,90,92,93] with the exception of the study that favored SILS over CLS. This finding may be explained by more rigorous lymph node harvesting to fulfill the oncologic criteria of minimal retrieval. In one recent meta-analysis[70], the number of nodes harvested was significantly increased in SILS compared with CLS (P = 0.035) with no evidence of statistical heterogeneity or bias. Conversely, another meta-analysis reported that the two techniques were equivalent for lymph node retrieval[66]. Nevertheless, the oncological appropriateness and quality of resection do not appear to be compromised with SILS techniques in colorectal cancer patients. In a case-matched comparative study with a mean follow-up of 13 mo, Papaconstantinou et al[92] reported a similar disease-free survival rate of 92% in the SILS and CLS groups. Moreover, the authors did not observe any port-site recurrence in either group; these findings are similar to those reported by Huscher et al[78] in a RCT after a follow-up of 22 mo. Finally, long-term outcomes of colorectal SILS for malignant diseases can not presently be assessed given the lack of long-term follow-up in the available data[64].

Cosmetic benefits were naturally expected from the early descriptions of SILS procedures given that a reduced incision length logically equals improved cosmesis[41,81]. Although refuted by some authors[69,74,86,90,91,93,94], many studies favored SILS given its significantly shorter incision[68,82,87,89]. This finding was confirmed by three meta-analyses[66,70,79]. However, Leblanc et al[81] suggested that cosmetic evaluation should only be undertaken after the healing process is complete. Moreover, most authors rely on subjective criteria, such as their own impression or collected feedback by nurses and medical team members[68,71,74,77,82]. Only a single study reported higher cosmetic score in SILS than in CLS but failed to show a difference in body image scores[87]. An objective cosmetic score that considers a patient’s perception of his/her body image needs to be developed as it may help provide a more accurate assessment of the cosmetic advantage of SILS over CLS[47,66,76,105]. On the other hand, it is natural to accept the cosmetic advantage of SILS when performed in a planned stoma site, such as abdominoperineal resection, total colectomy or restorative proctocolectomy for familial adenomatous polyposis or ulcerative colitis[46,53,55,73,77,112]. In patients with previous colectomy, the second-stage restorative procedure can be accomplished by placing the SILS port in the right iliac fossa after mobilization of the terminal ileostomy[54]. In these particular settings, the cosmetic benefit combines with the reduction of parietal trauma because the single access point is used for organ dissection, specimen extraction and stoma formation, thus moving closer to the aspired result of a virtually scar-free procedure.

Overall conversion rates vary from 0% to 16.7%[47,64,69,71,72,74-76,78,84,85,90,94,96,100,101] and from 0% to 16.6%[45,47,64,69,72-78,90,93,96,113,114] for LCS and open surgery, respectively. However, two recent collective reviews[79,105] estimated that conversion rates ranged from 3.7% to 8.0% and 1.6% to 2% for CLS and open surgery, respectively. These results appear to be more adequate to actual applications because high conversion rates were commonly stated during the learning period in early series[72,85]. Nonetheless, SILS does not increase the conversion rates in most comparative studies[69,74,77,84,86,88-92,94,100]. This observation was confirmed in three meta-analyses on colorectal procedures that demonstrated comparable rates between the two techniques[66,70,79]. The most reported causes of conversions are bleeding and technical difficulties, such as adhesions, large tumors, poor visibility from thick omentum and perforated diverticulitis[45,47,72,74,76]. Additionally, significantly increased conversion rates have been reported in rectal surgery (up to 25%) compared with colonic resections (as low as 3%)[79]. In our opinion, a novel approach must primarily provide safety to gain widespread acceptance. At any time, every new technique should allow a fallback solution should the patient’s safety be compromised or if the expected result is suboptimal. This is our vision of the new era of laparoscopy, wherein an initial SILS technique possesses the potential to add additional trocar(s) in difficult cases, just as CLS permits conversion to laparotomy whenever deemed necessary by the surgeon. Conversion should not be perceived as a failure of the approach but rather a technical solution to provide a better outcome. With increasing experience, surgeons should naturally be able to perform the procedure exclusively with SILS more frequently.

The median duration of hospitalization is a particularly variable parameter driven by clinical factors (such as patient characteristics, type of performed surgery and occurrence of postoperative complications) and differences in hospital discharge practices (based on economic considerations and social support)[66]. Nevertheless, different comparative studies have questioned this issue, and most of these studies failed to demonstrate significant reduction of the length of stay with SILS[68,69,74,75,82,84,85,87-90,93,94,100]. Others claimed that patients operated on with SILS were discharged significantly earlier than patients with CLS[77,83,86,91,92,95]. All results of the three meta-analyses converged to suggest the advantage of SILS in terms of duration of hospitalization[66,70,79]. Because reduced postoperative pain is questionable and the complications profile is comparable (see above), faster postoperative recovery after SILS may be attributed to earlier bowel movement and faster tolerance to normal diet, as demonstrated in a couple of studies[75,77] and confirmed in a single meta-analysis[66]. Since 1997, when Kehlet et al[115] introduced the concept of enhanced recovery after surgery, different measures and strategies were implemented to reduce surgical stress and improve the postoperative course. Among these strategies, laparoscopy has been proven to play a crucial role in patients undergoing colorectal resection[116-119]. Apart from the controversial benefits of new minimally invasive techniques per se, we consider SILS and NOTES perfectly integrate the trend of reducing the surgical burden. Thus, these techniques may not fully reveal their presumed advantages unless integrated in a global fast-track strategy.

When initially compared with conventional laparoscopy, SILS was considerably more expensive than CLS due to newly released sophisticated trocars and the common use of dedicated instruments[81]. With increasing interest in SILS and subsequent competition between industrials, recent studies claimed that the cost of the SILS port is only a little more than four conventional ports[65,84]. Surprisingly, in a comparative study, Fujii et al[68] demonstrated that the cost of access instruments in SILS was significantly cheaper than CLS. The initially reported cost excess may be outweighed by accumulating experience that leads to a reduction in operative time and routine usage of conventional instruments. However, only a demonstration of reduced morbidity, faster postoperative recovery and reduced length of stay will ultimately render SILS cost-effective[70,105].

Since the initial reports on SILS, early postoperative mortality has been anecdotally reported. This observation is confirmed by recent collective reviews that estimate mortality rates to be less than 1% after colorectal SILS[76,105]. A unique case of intraoperative death is reported in the current literature[47]. The event was secondary to the avulsion of the middle colic vein during colon exteriorization, leading to massive blood loss and subsequent multi-organ failure. Adair et al[85] declared a case of early postoperative death from pulmonary embolism. Two cases of postoperative death were described; one secondary to cardiopulmonary failure on the following day after SILS sigmoidectomy[112] and the other as a complication from metastatic disease after palliative SILS right colectomy[95]. Given that mortality rates are low among both SILS and CLS, comparison requires a large randomized study with precise clustering of patients based on their operative risks.


The human “pure” colorectal NOTES experience started with Bernhardt et al[120] and Palanivelu et al[121], who described the transvaginal appendicectomy in 2008. A single-canal standard gastroscope was used as the sole instrument, and the procedure was successfully performed as an “atypical” endoscopic intervention. Rapidly, the limits of conventional endoscopic instruments were expected if more complex colorectal NOTES procedures were to be performed. In fact, colorectal surgery comprises wide organ dissection and commonly necessitates the restoration of continuity (i.e., confection of an anastomosis). The latter represents the most crucial limiting step for NOTES. Meanwhile, as bridges for “pure” NOTES, alternative techniques, such as “hybrid” NOTES and transanal TEM, have extended the application of these novel techniques in humans.

After the first report of transanal sigmoid resection in cadavers by Whiteford et al[30] and the demonstration of its feasibility and safety in swine[122,123], Sylla et al[124] described the first successful total mesorectum excision (TME) using transanal endoscopic microsurgery with laparoscopic assistance in a human. Later, Zorron et al[33] reported two successful clinical cases of laparoscopy-assisted transanal TME: one with the use of a standard colonoscope and the other with a transanal single port device. To date, a couple of small, effective series promoted the feasibility of transanal TME with minimal laparoscopic assistance for rectal cancer[35-38]. In addition to proof of feasibility, acceptable complication rates and appropriateness of oncological resection, efforts are still needed for technique optimization and routine clinical application. Recently, Leroy et al[125] described the first case of “pure” NOTES transanal TME with intraperitoneal division of the colon and a side-to-end hand-sewn coloanal anastomosis in a woman. However, considerable work is still required for standardization of these techniques before clinical application can be routinely advocated. Clinical postoperative advantages and long-term oncological outcomes are further issues to be assessed if we aim to precisely identify the real place for these emerging techniques among conventional approved procedures. In our experience (in press), “pure” NOTES TME for rectal cancer was achieved in 10 of the 16 selected patients. These patients had hand-sewn coloanal anastomosis without diverting stoma. Lymph node dissection, vessels ligation and splenic flexure mobilization were performed through the unique transanal approach with conventional laparoscopic instruments. We demonstrated a favorable morbidity profile with appropriate oncological parameters even after neoadjuvant chemoradiotherapy. The “down-to-up” TME allows for a magnified view, shorter focal length between the operator’s eye and the most critical part of the mesorectum (i.e., its distal half), better definition of the pelvic nerves, less disruption of the distal mesorectal cone and better sphincter conservation for very low rectal tumors. In addition, preservation of the abdominal wall is achieved, and the cosmetic goal is reached. In the other six patients who needed laparoscopic abdominal assistance, we consider the umbilical SILS (except for abdominoperineal amputation) to be the ideal access site, combining direct vision for “up-to-down” mesorectum dissection, ease of splenic flexure dissection, a diverting stoma site and an improved cosmetic result (i.e., after stoma closure).

The minilaparoscopy-assisted transvaginal approach for colorectal procedures was initiated by Lacy et al[126] and Burghardt et al[127], who achieved the first radical sigmoidectomy and right colectomy, respectively. Since then, minimally invasive surgeons have integrated natural orifice access to their repertoire. Minilaparoscopy-assisted natural orifice surgery (MA-NOS) refers to a surgery initially using NOTES with the addition of a laparoscopic tool. The largest port is then hidden in the natural orifice, which serves as both a working channel and an extraction site. Lacy et al[128] described the first laparoscopically assisted transrectal MA-NOS for total colectomy in a man. They stated that until longer, more flexible, better-adapted instruments were available to address the specific needs of NOTES, laparoscopic assistance should be provided, at least to assist with visualization, retraction and full-thickness closure of viscerotomy. Recently, Fuchs et al[129] reported their prospectively collected data on minilaparoscopy-assisted transanal colon resection for benign diseases in women. All tasks requiring a port diameter > 5 mm were transanally performed via a specially designed transanal endoscopic applicator. The authors showed that a transcolonic route was feasible and safe in humans, representing a major encouraging argument in favor of “pure” NOTES application.

On the other hand, natural orifice specimen extraction (NOSE) aims to reduce the abdominal wall trauma induced by specimen retrieval in laparoscopy[130-132]. A recent prospective report confirmed that the colon specimen could be extracted through the anus or vagina with acceptable morbidity rates[133]. Transanal NOSE is deemed feasible and safe for rectal cancer according to the collected results in a 2-year follow-up study[134]. Further improvement consisted of the NOSE-SILS combination, including when the laparoscopic port is hidden within the umbilicus or an existing or planned stoma site, allowing for the performance of a virtually scarless surgery[131,135]. Leroy et al[136] described the first transumbilical SILS sigmoidectomy with transrectal specimen extraction. Based on the success of the procedure, the authors insisted on the need for a prospective study to assess feasibility, infectious risks, safety in oncologic cases and functional outcomes for the short- and long-term.


With growing experience in colorectal resections, it became obvious that SILS generates new challenges and magnifies difficulties compared with LCS[65,71,81]. Even experienced surgeons are facing a new learning curve because the skills required for SILS are different from those acquired in LCS[137]. The handling of straight instruments in parallel with the laparoscope through a small single incision decreases the range of movement for the surgeon and complicates the holding of the camera by the assistant[95]. Given the inline axis of the camera and the instruments, the movement of one of the instruments may result in inadvertent displacement of the others. This explains the difficulty encountered when performing even relatively simple tasks[138]. Furthermore, the lack of instrument triangulation increases the complexity of organ exposure and dissection[73,81,95]. This is particularly evident in SILS for colorectal procedures given that the exposure of different abdominal quadrants is often required; this feature is in contrast with cholecystectomy or appendicectomy, which both involve only one abdominal quadrant[139].

To regain triangulation and improve exposure, initial reports found it judicious to use specially designed, curved, S-shaped and reticulating instruments in colorectal SILS[41,81]. To date, only a few teams still recommend the adoption of these dedicated tools[71,87,89,112,136]. Conversely, most authors consider the use of these tools to add complexity[90,139]. As experience accumulates, difficulties are overcome, and most authors confirm that all colorectal SILS procedures can be performed using conventional straight instruments[42,45,47,53,65,67,69,74,77,78,84,91,100]. The use of tools of various lengths or an extra-long laparoscope, preferably with a right-angle light-cord, can be of value in reducing external clashing[88,90]. In several cases, a semi-rigid endoscope camera with a flexible tip (EndoEye; Olympus America, Center Valley, PA, United States) expands visualization possibilities and brings additional safety during dissection[139].

In a desire to overcome these difficulties and because SILS might serve as a step toward NOTES, we wondered whether we could adhere to the fundamentals of endoscopy. For a gastroenterologist performing operative endoscopy, the operator handles both the visualization task and the effector instrument, so that eyes and hands depend of the same brain. As a result, inefficacious time-outs during the procedures are shortened and the execution of orders is accelerated. Thus, we advise holding the camera in one hand and the operative instrument in the other. According to this scheme, the role of the assistant is to retract the organs and tissues, providing a “neo-triangulation”. Giving this static task to another person significantly reduces the conflict of instruments in the reduced space available. We consider that this setting considerably shortens and facilitates the learning curve in early experiences.

SILS application in inflammatory bowel disease harbors further specific difficulties. In the case of total colectomy, most authors advocate a clockwise dissection because the right hemicolon represents the most difficult part of the procedure and is associated with the highest rate of conversion[140-142]. In restorative proctocolectomy, the SILS port is ideally inserted at the planned site of ileostomy in the right iliac fossa[54]. However, to facilitate exposure for initial cases, alternative placement of the SILS port in the umbilicus has been described[143]. The stoma site in the right iliac fossa is then used for an additional 5-12 mm port, resulting in a hybrid SILS procedure.

Because SILS is technically challenging, efforts have been delivered to identify clinical parameters associated with increased difficulty. Some authors consider emergent conditions, T4 tumors and a history of abdominal surgery to be contraindications for the procedure[45,47,69,78,84]. A poor ASA score[45,77,90] and a large bulky mass[45,73,77,90] have also been reported as contraindications. Visceral obesity stands as a major clinical parameter that increases the dissection difficulty[43], lengthens the operative time[43] and predisposes to conversion[69]. Early reports[65,72,78,85] focused on careful selection of patients for initial SILS procedures. In early experiences, it was prudent to consider patients with no history of inflammatory disease (i.e., diverticulitis) or prior abdominopelvic surgery as well as BMI < 30 kg/m2[45] as surgical candidates.

Various adjunct procedures have been proposed to overcome the difficulty of SILS. Leroy et al[144] reported the usefulness of locking the anvil of the circular stapler in the proximal colon by a transparietal magnet to facilitate mesenteric dissection. The authors suggest that this technique harbors several additional advantages, such as the performance of a “fully laparoscopic” procedure with intraperitoneal anastomosis, solving the issue of fascia incision enlargement. This feature is particularly useful in left-sided safe and carries no increased risk for infectious complication[145]. Another comparable trick utilizing a magnetized intracorporeal vascular clip to retract the organ via an extracorporeal magnet was described by Uematsu et al[103]. Finally, Fujii et al[68] described the colon-lift technique as an easy, efficient and economical trick that does not require special instruments and may be applied to radical resections.

Because both SILS and NOTES present the same conformational challenges of inline vision, absence of triangulation and difficult surgical exposure, it could be argued that application of colorectal SILS is a step towards colorectal NOTES with a potential transfer of skills[65]. However, no consistent data are currently available to support this argument.


As initially identified by the NOSCAR[57] and further outlined by the regular meetings of the SAGES/ASGE and EAES/ESGE societies[146-149], NOTES still exposes technical issues that need to be resolved before standard human application can occur. These issues include ideal access to the peritoneal cavity, prevention of infections, viscerotomy closure, suturing/anastomotic devices, spatial orientation and the development of an adequate multitasking operating platform. NOTES techniques also require near-perfect endoscopic skill[30] and raise an ethical problem regarding the injury of healthy access organs[150]. In a recent evaluation of ergonomics, NOTES was found to uniquely limit visualization, complicate tissue manipulation and reduce the ability to autonomously perform tasks. NOTES requires close collaboration among the entire team to safely complete the procedure[151]. In this review, special attention is directed toward the specific difficulties of NOTES application in colorectal surgery.

In early NOTES experiences for end-organ resection, such as cholecystectomy, transgastric and transvaginal accesses were favored over transanal and transcolonic approaches[62,63,152,153]. This preference was driven by major unresolved issues regarding the risks of infection, bacteria spillage in the peritoneal cavity and secondary leakage after closure[26]. However, theoretical microscopic fecal contamination is not a specific risk to NOTES and may also apply to laparoscopic, open and TEM resections[128]. To fully elucidate this concern, a prospective study comparing peritoneal contamination in NOSE/NODES and non-NOSE/NODES colorectal procedures should be performed[136]. The transgastric approach exposes the blood vessels and surrounding organs to the risk of injury. Moreover, it does not provide adequate access to the pelvis and the lower part of the abdomen. To date, colorectal resection has not yet been achieved through the transgastric route[149]. Vaginal access can be realized via direct vision through a speculum or direct laparoscopic visualization. The vaginotomy is usually executed at the posterior fornix or at the apex in patients with a previous hysterectomy[154]. To improve access, the uterus can be anteriorly fixed using a transparietal suture. For increased reach, laparoscopic bariatric instruments can be used when working through the vagina. In such a limited access site, a flexible tip laparoscope can significantly reduce the intersection of the instruments[154]. The transvaginal approach offers the advantage of direct access to the pelvic organs, but the technique is only applicable in 50% of the population. The procedure also exposes patients to the potential risks of dyspareunia and infertility; however, the actual occurrence of these risks has not yet been specified in clinical studies[147]. However, when precise precautions and contraindications are respected, the complication rate of the transvaginal approach is reported to be less than 5% according to the latest Euro-NOTES status paper[149]. In a prospective cohort study of 106 sexually active women, Linke et al[155] confirmed that the transvaginal access technique is safe, with a risk of sexual dysfunction in less than 5% at one year. The transanal/transrectal approach offers several valuable advantages for colorectal surgery. First, the entry point and secure closure can be achieved under direct view in all patients[124,156]. Second, this approach provides direct access to the operative field and upper abdominal quadrants through a short anal canal. Third, it allows passage of larger diameter instrumentation and retrieval of larger specimens[33]. However, removal of organs through the anus is clearly limited by the extent to which the anal canal can be safely dilated. Despite the lack of objective limits, specimens with large tumors or bulky mesenteries are not ideal candidates for this technique. The potential effect of prolonged anal dilation on short- and long-term anal sphincter function requires objective evaluation[32].

On the other hand, efforts are constantly delivered to assure safe and sterile colonic access. Ultrasound guidance after decontaminating the hydroperitoneum for ideal entry point definition[27,28], curved over tube[157] and dedicated closure technique[27-29,158] are promising experimental practices that may encourage the first human application[158]. Even if obviously present, the risk of contamination remains subject to further discussions. Fifteen years ago, in a prospective, double-blind, randomized controlled study, Schardey et al[159] showed that perioperative oral decontamination significantly reduces esophagojejunal anastomotic leakage after total gastrectomy. The use of non-absorbable antibiotics, such as polymyxin, tobramycin, vancomycin and amphotericin B, may lower the bacterial load and prevent infection, even if total sterility is not achieved. It is possible that a similar practice with antibiotic enemas can resolve the issue of postoperative infection and leakage after transcolonic/transrectal NOTES. This hypothesis deserves to be evaluated in a well-designed study before clinical application. Moreover, acquired experience during war surgery changed the paradigm in the treatment of colorectal wounds (i.e., systematic stoma or exclusion)[160,161]. In certain circumstances, especially after simple perforation with acceptable vascularity, ideal closure can be performed with outcomes comparable to conventional treatment. NOTES through the colon or rectum is a perfect illustration of these ideal situations because access is achieved through an otherwise healthy organ. The 2010 summary report of the Euro-NOTES[148] recommends local disinfection and perioperative antibiotics for the transvaginal and transgastric approaches, but antibiotic lavage does appear to be necessary. At this stage, the transanal/transcolonic approach was not widely used and specific recommendations have not been updated so far.

One of the most attractive features of transanal NOTES is the availability of TEM as a stable platform. In this setting, the transanal route is no longer conceived as a port for remote organ access through an otherwise healthy viscera (like the transgastric or the transvaginal routes). Instead, the colotomy/proctotomy is created through the diseased organ itself and secondarily closed in the form of an anastomosis[124]. This technique resolves the issues of viscerotomy closure and adequate endoluminal purse string, which remain major difficulties in NOTES[30,162]. However, the TEM platform was conceived twenty years ago initially for the resection of endoluminal rectal lesions[34]. The extension of the TEM technique towards “pure” NOTES must be accompanied by the development of improved, more convenient devices for greater intra-abdominal access[154]. In an experimental study of radical sigmoidectomy using TEM, Whiteford et al[30] outlined the specific technical and instrumental limitations encountered in this technique. The acute angle of the sacral promontory considerably limits the instrument’s reach and generates difficulty for colon mobilization beyond the descending part. In a comparative study in cadavers, Rieder et al[31] showed that conventional TEM instrumentation does not allow adequate colon mobilization when compared with standard laparoscopy. To perform proper left colectomy, a combined technique using transgastric flexible access has been described in experimental models[122,163,164]. However, these promising experiments have not reached clinical application to date. The arrival of new, dedicated platforms is a promising step for the development of NOTES. Zorron et al[33,156] claim that the perirectal NOTES access is easier to learn and allows the freedom for more creative dissection than the TEM platform. Likewise, the Transanal Endoscopic Operations (TEO®) (Karl Storz, Tuttlingen, Germany) facilitates circular, full-thickness rectal resection for both intra- and extra-peritoneal application[165]. In preparation for transitioning to human application, Telem et al[166] reported a series of transanal NOTES rectosigmoid resections in 32 fresh human cadavers using TEO® transanally. The procedure was successfully performed using transanal dissection alone in 19 cadavers, necessitating transgastric endoscopic assistance in 5 cadavers and laparoscopic assistance in 8 cadavers. The mesorectum was intact in all cases, but the specimen length was increased in cases where assistance was employed. However, enteric perforation occurred in 8 cases (25%), all of which were cadavers undergoing “pure” NOTES. This highlights the limits of the transanal approach for clinical application unless combined with a laparoscopic approach. Recently, Leroy et al[167] described the perirectal oncologic gateway for retroperitoneal endoscopic single-site surgery using the IsisScope (Karl Storz, Tüttlingen, Germany) passed through the TEO for the accomplishment of “pure” NOTES total mesorectum excision in pigs. To our knowledge, no clinical series has validated the added value of these instruments in terms of safety, morbidity or oncological outcomes.


The irrevocable benefits of CLS in colorectal surgery without compromise of functional or oncological outcomes have encouraged surgeons to further reduce invasiveness[1-15]. The fundamental hypotheses driving SILS promotion are reduced postoperative complications and pain, shorter hospital stays, earlier returns to normal activity, fewer port-site complications and improved cosmetic results. With approximately equivocal results, SILS has not yet been proven to substantially improve outcomes when compared with CLS. However, actual data, including all available meta-analyses, are excluded from retrospective series, resulting in inevitable heterogeneity and bias in conclusions[66,70,79].

From another point of view, the present literature failed to demonstrate that the postoperative course or the patient’s safety was degraded when SILS was used instead of CLS. To date, data have not consistently proven that SILS increases postoperative pain, augments complication/morbidity rates, induces proper port site complications, prolongs the duration of hospitalization or affects the mortality rate. Moreover, recent studies demonstrate that appropriate resection of colorectal neoplasms can be achieved with SILS and provide short-term results comparable with CLS[68,69,74,77,78,82,84-86,90,92,93]. Based on these findings, it is undeniable that SILS represents a potential alternative to CLS. In addition, if the intuitive cosmetic advantage of SILS over CLS[41,51,68,74,77,82] is confirmed by the means of objective scores, one may consider SILS as the preferred approach in this new era of laparoscopy.

Despite fundamental differences (such as dissection in a single abdominal quadrant, resection of an end-organ with no need for anastomosis and absence of oncologic requirements), the comparison of SILS with conventional laparoscopic techniques in well-standardized procedures, such as laparoscopic cholecystectomy, can aid in the evaluation of its advantages, safety and limitations. In a systematic review and meta-analysis performed by Arezzo et al[168] encompassing approximately 1000 patients, SILS offered similar overall morbidity and parietal complications compared with conventional laparoscopy. The claimed advantages of enhanced cosmesis and reduced postoperative pain were confirmed despite longer operative times. Based on these encouraging results, the authors organized a multicenter randomized trial (NCT01104727) to provide a strong evidence-based evaluation of the benefits and risks of SILS[169]. This trial may allow for a better assessment of the real place of SILS among conventional laparoscopic techniques.

It is surprising that SILS emerged as a novel technique in colorectal surgery before some of its fundamental advantages could be validated in well-designed studies. The most illustrative example is the absence of evidence for surgical stress reduction in SILS when compared with CLS. To date, a single study is available that addresses this issue[89]. Based on C-reactive protein levels as the sole marker of inflammation, this study failed to demonstrate any significant difference between the two groups in a small number of patients. In the current era of evidence-based medicine, it is obvious that SILS did not yet acquire solid statistical confirmation. However, large concordant clinical experiences bring sufficient empirical proof for feasibility and safety in benign and malignant colorectal diseases. We believe that unless well-designed studies demonstrate irrevocable disadvantages of SILS, this promising technique henceforward will occupy a privileged place in the armamentarium of today’s colorectal surgeon.

Presently, four RCTs (NCT01320267, NCT01656746, NCT01319890 and NCT01480128, ) are underway comparing SILS with CLS in colorectal surgery. Answers are particularly awaited regarding the potential benefits on the postoperative course (i.e., reduced surgical stress, post operative complications and pain, improved patient satisfaction and safety), the long-term surgical outcome (i.e., bowel function and late wound hernia) and the oncological appropriateness of the short-term (i.e., margins, lymph node retrieval) and long-term results (i.e., global, disease-free and disease-specific survival rates)[66]. Consequently, the cost-effectiveness of SILS can be thoroughly evaluated given that only solid proof of postoperative course improvement, reduced hospital stay and/or lower complication rate can outweigh the induced cost increase[64].

Rectal SILS procedures are typically integrated in large colorectal series. As mentioned by Maggiori et al[79], a study dedicated to rectal SILS that includes more than 20 patients is not available. To the best of our knowledge, the results of SILS proctectomy have never been assessed nor compared with those of CLS. In a recent meta-analysis, Fung et al[64] indicated that the role of SILS in rectal surgery requires a separate study. In this respect, data from a RCT (NCT01579721, ) have been collected for the assessment of SILS in rectal cancer. The results are eagerly awaited and are expected to provide valuable, unheralded knowledge on rectal surgery and the real benefits of SILS for proctectomy.

In today’s enthusiastic vision of surgery, NOTES represents the “ideal scar-free surgery” with the claimed advantages of reduced postoperative pain, quicker recovery, less postoperative morbidity and optimal cosmesis. However, since the first definition of the NOTES concept in 2006[57], major difficulties have inhibited the clinical breakthrough of NOTES. Efforts are regularly delivered by the SAGES/ASGE and EAES/ESGE societies to promote research and safely bring this concept into clinical practice[146-149,170]. In this respect, the NOSCAR and the EURO-NOTES Clinical Registries were developed to compile safety data and authorize human trials. In the 2-year activity report of Euro-NOTES[147], a total of 533 patients were entered. Cholecystectomy remains the most frequently performed procedure in 435 patients (81.6%) and was performed through the transvaginal approach in 423 patients (97.2%). Transanal/transrectal colorectal resections are noticeably gaining interest as potentially attested by the rapidly increasing number of procedures performed in humans. In almost one year, this number approximately tripled from 32 patients to greater than 100 patients in the Euro-NOTES activity report[147] and the latest summary of the 2012 Euro-NOTES meeting[170]. It is worth noting that, with the exception of peroral myotomy, transabdominal trocar has commonly been used for dissection and/or safe access, transforming the procedure into “hybrid” NOTES. This technical adjunct provides the required safety for the application of NOTES in humans during the initial experiences[147]. Case reports of “pure” colorectal NOTES have recently been described, but this approach has not yet achieved wide acceptance[170].

Among the topics at different committees, the risk of infection has been the most frequently discussed[149]. Statements concerning this issue have changed considerably since 2006-2007 when infectious problems were particularly feared, especially in the transcolonic/transanal approaches. This attitude has changed with repetitive successful descriptions of transanal/transrectal/trancolonic NOTES procedures[170]. Initial recommendations of the Euro-NOTES regarding infection were published in 2011[148]. This authority recently stated that “infection is no longer a major concern, and the frequency of infectious NOTES complications is rather low¡ The danger of infection was overestimated in the beginning of NOTES research”. Under validated conditions of sterility and disinfection, the incidence of infections for all transluminal procedures ranges from 0.5% to 11%[149]. However, this paper also confirms the necessity of comparative prospective trials to validate these data and support the clinical application of NOTES.

Platforms and new technologies occupy a major portion of the discussions in the NOTES communities meetings[146,148,149,170]. Initial reports focused on the importance of close collaboration between surgeons, endoscopists, engineers and commercial providers to make NOTES a routine, daily practice. The principles features of the optimal multitasking platform have been described in the Euro-NOTES meeting summary from 2010[148]. However, such a flexible platform delivering all requirements for NOTES is not readily available for clinical practice[146,147,149,170]. Alternatively, during the past few years, new conceptual ideas and applications of available tools have at least partially compensated for this lack of innovative instruments. The “down-to-up” transanal TME represents the most illustrative example of this shift. This novel technique represents a practical application of the fundamentals of NOTES (i.e., natural orifice access and parallel working instruments) with the use of familiar tools (TEM platform and single-port devices)[146]. However, flexible NOTES platforms are still believed to further enlarge dissection possibilities and advance NOTES promises into practice[146,170]. These possibilities are almost entirely dependent on engineering innovations and commercial commitment in this field[146].

The guarantee of a safe endoluminal closure remains one of the fundamental problems limiting the application of NOTES in humans[146,148]. Several closure devices are currently available that promise appropriate endoluminal closure. However, laparoscopic control of adequate closure remains necessary until large-scale studies confirm the low failure rate[146]. From this point of view, transanal/transrectal colorectal resections represent a remarkable conceptual improvement toward “pure” NOTES possibilities by taking advantage of anastomosis to achieve a full-thickness site closure[149]. This finding is in complete accordance with the SAGES/ASGE assessment that controlled incision in the viscera is no longer perceived as an iatrogenic perforation and intraperitoneal contamination, as long as the viscerotomy closure is secure[146]. However, transcolonic/transrectal NOTES should be restricted to interventions where the access site is incorporated in the anastomosis and resected with the specimen[170]. Along with the presumed advantages of NOTES surgery, we insist that the “down-to-up” approach of the rectum brings considerable advantages regarding the preservation of pelvic nerves, distal mesorectal cone integrity and easier sphincter conservation. Larger clinical experiences are needed to fully standardize this technique and validate its presumed advantages in well-designed studies. The ongoing prospective clinical trial initiated by Sylla et al[124] (NCT01340755) will hopefully provide valuable knowledge on transanal TME for rectal cancer.

Since the initial reports, working groups focused on interdisciplinary approaches and outlined the need for close collaboration between surgeons and gastroenterologists[148]. It is now evident that NOTES requires high qualifications in both interventional endoscopy and advanced laparoscopy[146]. A critical step before the application of NOTES to patients consists of long experimental training phases as well as extensive clinical and technical experience[149]. Accreditation by scientific societies through certified experts in the field may also contribute to success[147].

In contrast to the first reports in which the transgastric route was favored (mostly by gastroenterologists), the present data indicate that NOTES can be performed for multiple procedures through different organs with acceptable morbidity and failure rates[149]. NOTES techniques are increasingly being performed in dedicated centers worldwide[146,149]. Continuing assessment of results is crucial for the standardization of future procedures and validation of indications[147]. Today, feasibility is no longer a concern, but the full potential of NOTES must be revealed[146]. Limited experience in the clinical application of colorectal NOTES procedures hinders clinical outcome analysis at the moment[162]. NOTES remains a constantly progressing concept with considerable technological and practical hurdles that must be overcome[156]. Safety remains a prerequisite before confrontation in clinical trials and confirmation of the presumed advantages of this “ideal” approach.


P- Reviewer: Arezzo A, Botaitis SC, Tsimogiannis K S- Editor: Gou SX L- Editor: A E- Editor: Zhang DN

1.  Schwenk W, Haase O, Neudecker J, Müller JM. Short term benefits for laparoscopic colorectal resection. Cochrane Database Syst Rev. 2005;CD003145.  [PubMed]  [DOI]
2.  Braga M, Vignali A, Gianotti L, Zuliani W, Radaelli G, Gruarin P, Dellabona P, Di Carlo V. Laparoscopic versus open colorectal surgery: a randomized trial on short-term outcome. Ann Surg. 2002;236:759-66; disscussion 767.  [PubMed]  [DOI]
3.  Bonjer HJ, Hop WC, Nelson H, Sargent DJ, Lacy AM, Castells A, Guillou PJ, Thorpe H, Brown J, Delgado S. Laparoscopically assisted vs open colectomy for colon cancer: a meta-analysis. Arch Surg. 2007;142:298-303.  [PubMed]  [DOI]
4.  Delaney CP, Chang E, Senagore AJ, Broder M. Clinical outcomes and resource utilization associated with laparoscopic and open colectomy using a large national database. Ann Surg. 2008;247:819-824.  [PubMed]  [DOI]
5.  Forgione A, Leroy J, Cahill RA, Bailey C, Simone M, Mutter D, Marescaux J. Prospective evaluation of functional outcome after laparoscopic sigmoid colectomy. Ann Surg. 2009;249:218-224.  [PubMed]  [DOI]
6.  Lacy AM, García-Valdecasas JC, Delgado S, Castells A, Taurá P, Piqué JM, Visa J. Laparoscopy-assisted colectomy versus open colectomy for treatment of non-metastatic colon cancer: a randomised trial. Lancet. 2002;359:2224-2229.  [PubMed]  [DOI]
7.  Clinical Outcomes of Surgical Therapy Study Group. A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med. 2004;350:2050-2059.  [PubMed]  [DOI]
8.  Guillou PJ, Quirke P, Thorpe H, Walker J, Jayne DG, Smith AM, Heath RM, Brown JM. Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial. Lancet. 2005;365:1718-1726.  [PubMed]  [DOI]
9.  Veldkamp R, Kuhry E, Hop WC, Jeekel J, Kazemier G, Bonjer HJ, Haglind E, Påhlman L, Cuesta MA, Msika S. Laparoscopic surgery versus open surgery for colon cancer: short-term outcomes of a randomised trial. Lancet Oncol. 2005;6:477-484.  [PubMed]  [DOI]
10.  Kuhry E, Schwenk WF, Gaupset R, Romild U, Bonjer HJ. Long-term results of laparoscopic colorectal cancer resection. Cochrane Database Syst Rev. 2008;CD003432.  [PubMed]  [DOI]
11.  Green BL, Marshall HC, Collinson F, Quirke P, Guillou P, Jayne DG, Brown JM. Long-term follow-up of the Medical Research Council CLASICC trial of conventional versus laparoscopically assisted resection in colorectal cancer. Br J Surg. 2013;100:75-82.  [PubMed]  [DOI]
12.  Arezzo A, Passera R, Scozzari G, Verra M, Morino M. Laparoscopy for rectal cancer reduces short-term mortality and morbidity: results of a systematic review and meta-analysis. Surg Endosc. 2013;27:1485-1502.  [PubMed]  [DOI]
13.  Kellokumpu IH, Kairaluoma MI, Nuorva KP, Kautiainen HJ, Jantunen IT. Short- and long-term outcome following laparoscopic versus open resection for carcinoma of the rectum in the multimodal setting. Dis Colon Rectum. 2012;55:854-863.  [PubMed]  [DOI]
14.  Arezzo A, Passera R, Scozzari G, Verra M, Morino M. Laparoscopy for extraperitoneal rectal cancer reduces short-term morbidity: Results of a systematic review and meta-analysis. United European Gastroenterol J. 2013;1:32-47.  [PubMed]  [DOI]
15.  Agha A, Benseler V, Hornung M, Gerken M, Iesalnieks I, Fürst A, Anthuber M, Jauch KW, Schlitt HJ. Long-term oncologic outcome after laparoscopic surgery for rectal cancer. Surg Endosc. 2014;28:1119-1125.  [PubMed]  [DOI]
16.  Tonouchi H, Ohmori Y, Kobayashi M, Kusunoki M. Trocar site hernia. Arch Surg. 2004;139:1248-1256.  [PubMed]  [DOI]
17.  Helgstrand F, Rosenberg J, Bisgaard T. Trocar site hernia after laparoscopic surgery: a qualitative systematic review. Hernia. 2011;15:113-121.  [PubMed]  [DOI]
18.  Pelosi MA, Pelosi MA. Laparoscopic supracervical hysterectomy using a single-umbilical puncture (mini-laparoscopy). J Reprod Med. 1992;37:777-784.  [PubMed]  [DOI]
19.  Mattioli G, Pini-Prato A, Barabino A, Gandullia P, Avanzini S, Guida E, Rossi V, Pio L, Disma N, Mameli L. Laparoscopic approach for children with inflammatory bowel diseases. Pediatr Surg Int. 2011;27:839-846.  [PubMed]  [DOI]
20.  Varadarajulu S, Tamhane A, Drelichman ER. Patient perception of natural orifice transluminal endoscopic surgery as a technique for cholecystectomy. Gastrointest Endosc. 2008;67:854-860.  [PubMed]  [DOI]
21.  Li W, Xu H, Wang ZK, Fan ZN, Ba SD, Zou DW, Ren X, Hu B, Huang YH, Sun MJ. Natural Orifice Translumenal Endoscopic Surgery (NOTES): patients’ perceptions and attitudes. Dig Dis Sci. 2011;56:2415-2422.  [PubMed]  [DOI]
22.  McGee MF, Rosen MJ, Marks J, Onders RP, Chak A, Faulx A, Chen VK, Ponsky J. A primer on natural orifice transluminal endoscopic surgery: building a new paradigm. Surg Innov. 2006;13:86-93.  [PubMed]  [DOI]
23.  Kalloo AN, Singh VK, Jagannath SB, Niiyama H, Hill SL, Vaughn CA, Magee CA, Kantsevoy SV. Flexible transgastric peritoneoscopy: a novel approach to diagnostic and therapeutic interventions in the peritoneal cavity. Gastrointest Endosc. 2004;60:114-117.  [PubMed]  [DOI]
24.  Autorino R, Yakoubi R, White WM, Gettman M, De Sio M, Quattrone C, Di Palma C, Izzo A, Correia-Pinto J, Kaouk JH. Natural orifice transluminal endoscopic surgery (NOTES): where are we going? A bibliometric assessment. BJU Int. 2013;111:11-16.  [PubMed]  [DOI]
25.  Moris DN, Bramis KJ, Mantonakis EI, Papalampros EL, Petrou AS, Papalampros AE. Surgery via natural orifices in human beings: yesterday, today, tomorrow. Am J Surg. 2012;204:93-102.  [PubMed]  [DOI]
26.  Fong DG, Pai RD, Thompson CC. Transcolonic endoscopic abdominal exploration: a NOTES survival study in a porcine model. Gastrointest Endosc. 2007;65:312-318.  [PubMed]  [DOI]
27.  Elmunzer BJ, Chak A, Taylor JR, Trunzo JA, Piraka CR, Schomisch SJ, Rising GM, Elta GH, Scheiman JM, Ponsky JL. Hydroperitoneum-facilitated EUS-guided peritoneal entry and closure of alternate access sites for NOTES. Surg Innov. 2010;17:101-107.  [PubMed]  [DOI]
28.  Denk PM, Swanström LL, Whiteford MH. Transanal endoscopic microsurgical platform for natural orifice surgery. Gastrointest Endosc. 2008;68:954-959.  [PubMed]  [DOI]
29.  Sporn E, Miedema BW, Bachman SL, Astudillo JA, Loy TS, Calaluce R, Thaler K. Endoscopic colotomy closure after full thickness excision: comparison of T fastener with multiclip applier. Endoscopy. 2008;40:589-594.  [PubMed]  [DOI]
30.  Whiteford MH, Denk PM, Swanström LL. Feasibility of radical sigmoid colectomy performed as natural orifice translumenal endoscopic surgery (NOTES) using transanal endoscopic microsurgery. Surg Endosc. 2007;21:1870-1874.  [PubMed]  [DOI]
31.  Rieder E, Spaun GO, Khajanchee YS, Martinec DV, Arnold BN, Smith Sehdev AE, Swanstrom LL, Whiteford MH. A natural orifice transrectal approach for oncologic resection of the rectosigmoid: an experimental study and comparison with conventional laparoscopy. Surg Endosc. 2011;25:3357-3363.  [PubMed]  [DOI]
32.  Cataldo PA, O’Brien S, Osler T. Transanal endoscopic microsurgery: a prospective evaluation of functional results. Dis Colon Rectum. 2005;48:1366-1371.  [PubMed]  [DOI]
33.  Zorron R, Phillips HN, Coelho D, Flach L, Lemos FB, Vassallo RC. Perirectal NOTES access: “down-to-up” total mesorectal excision for rectal cancer. Surg Innov. 2012;19:11-19.  [PubMed]  [DOI]
34.  Buess G, Kipfmüller K, Ibald R, Heintz A, Hack D, Braunstein S, Gabbert H, Junginger T. Clinical results of transanal endoscopic microsurgery. Surg Endosc. 1988;2:245-250.  [PubMed]  [DOI]
35.  Sylla P, Bordeianou LG, Berger D, Han KS, Lauwers GY, Sahani DV, Sbeih MA, Lacy AM, Rattner DW. A pilot study of natural orifice transanal endoscopic total mesorectal excision with laparoscopic assistance for rectal cancer. Surg Endosc. 2013;27:3396-3405.  [PubMed]  [DOI]
36.  de Lacy AM, Rattner DW, Adelsdorfer C, Tasende MM, Fernández M, Delgado S, Sylla P, Martínez-Palli G. Transanal natural orifice transluminal endoscopic surgery (NOTES) rectal resection: “down-to-up” total mesorectal excision (TME)--short-term outcomes in the first 20 cases. Surg Endosc. 2013;27:3165-3172.  [PubMed]  [DOI]
37.  Dumont F, Goéré D, Honoré C, Elias D. Transanal endoscopic total mesorectal excision combined with single-port laparoscopy. Dis Colon Rectum. 2012;55:996-1001.  [PubMed]  [DOI]
38.  Lacy AM, Adelsdorfer C, Delgado S, Sylla P, Rattner DW. Minilaparoscopy-assisted transrectal low anterior resection (LAR): a preliminary study. Surg Endosc. 2013;27:339-346.  [PubMed]  [DOI]
39.  Chouillard E, Chahine E, Khoury G, Vinson-Bonnet B, Gumbs A, Azoulay D, Abdalla E. NOTES total mesorectal excision (TME) for patients with rectal neoplasia: a preliminary experience. Surg Endosc. 2014;28:3150-3157.  [PubMed]  [DOI]
40.  Remzi FH, Kirat HT, Kaouk JH, Geisler DP. Single-port laparoscopy in colorectal surgery. Colorectal Dis. 2008;10:823-826.  [PubMed]  [DOI]
41.  Bucher P, Pugin F, Morel P. Transumbilical single incision laparoscopic sigmoidectomy for benign disease. Colorectal Dis. 2010;12:61-65.  [PubMed]  [DOI]
42.  Chambers WM, Bicsak M, Lamparelli M, Dixon AR. Single-incision laparoscopic surgery (SILS) in complex colorectal surgery: a technique offering potential and not just cosmesis. Colorectal Dis. 2011;13:393-398.  [PubMed]  [DOI]
43.  Ramos-Valadez DI, Patel CB, Ragupathi M, Bartley Pickron T, Haas EM. Single-incision laparoscopic right hemicolectomy: safety and feasibility in a series of consecutive cases. Surg Endosc. 2010;24:2613-2616.  [PubMed]  [DOI]
44.  Ross SB, Hernandez JM, Sperry S, Morton CA, Vice M, Luberice K, Rosemurgy AS. Public perception of LESS surgery and NOTES. J Gastrointest Surg. 2012;16:344-355.  [PubMed]  [DOI]
45.  Vestweber B, Galetin T, Lammerting K, Paul C, Giehl J, Straub E, Kaldowski B, Alfes A, Vestweber KH. Single-incision laparoscopic surgery: outcomes from 224 colonic resections performed at a single center using SILS. Surg Endosc. 2013;27:434-442.  [PubMed]  [DOI]
46.  Rijcken E, Mennigen R, Senninger N, Bruewer M. Single-port laparoscopic surgery for inflammatory bowel disease. Minim Invasive Surg. 2012;2012:106878.  [PubMed]  [DOI]
47.  Waters JA, Rapp BM, Guzman MJ, Jester AL, Selzer DJ, Robb BW, Johansen BJ, Tsai BM, Maun DC, George VV. Single-port laparoscopic right hemicolectomy: the first 100 resections. Dis Colon Rectum. 2012;55:134-139.  [PubMed]  [DOI]
48.  Pelosi MA, Pelosi MA. Laparoscopic appendectomy using a single umbilical puncture (minilaparoscopy). J Reprod Med. 1992;37:588-594.  [PubMed]  [DOI]
49.  Navarra G, Pozza E, Occhionorelli S, Carcoforo P, Donini I. One-wound laparoscopic cholecystectomy. Br J Surg. 1997;84:695.  [PubMed]  [DOI]
50.  Esposito C. One-trocar appendectomy in pediatric surgery. Surg Endosc. 1998;12:177-178.  [PubMed]  [DOI]
51.  Bucher P, Pugin F, Morel P. Single port access laparoscopic right hemicolectomy. Int J Colorectal Dis. 2008;23:1013-1016.  [PubMed]  [DOI]
52.  Leroy J, Cahill RA, Peretta S, Marescaux J. Single port sigmoidectomy in an experimental model with survival. Surg Innov. 2008;15:260-265.  [PubMed]  [DOI]
53.  Geisler DP, Kirat HT, Remzi FH. Single-port laparoscopic total proctocolectomy with ileal pouch-anal anastomosis: initial operative experience. Surg Endosc. 2011;25:2175-2178.  [PubMed]  [DOI]
54.  Gash KJ, Goede AC, Kaldowski B, Vestweber B, Dixon AR. Single incision laparoscopic (SILS) restorative proctocolectomy with ileal pouch-anal anastomosis. Surg Endosc. 2011;25:3877-3880.  [PubMed]  [DOI]
55.  Geisler DP, Condon ET, Remzi FH. Single incision laparoscopic total proctocolectomy with ileopouch anal anastomosis. Colorectal Dis. 2010;12:941-943.  [PubMed]  [DOI]
56.  Rao GV, Reddy DN, Banerjee R. NOTES: human experience. Gastrointest Endosc. Clin N Am. 2008;18:361-370; x.  [PubMed]  [DOI]
57.  Rattner D, Kalloo A. ASGE/SAGES Working Group on Natural Orifice Translumenal Endoscopic Surgery. October 2005. Surg Endosc. 2006;20:329-333.  [PubMed]  [DOI]
58.  Kantsevoy SV, Jagannath SB, Niiyama H, Chung SS, Cotton PB, Gostout CJ, Hawes RH, Pasricha PJ, Magee CA, Vaughn CA. Endoscopic gastrojejunostomy with survival in a porcine model. Gastrointest Endosc. 2005;62:287-292.  [PubMed]  [DOI]
59.  Kantsevoy SV, Hu B, Jagannath SB, Vaughn CA, Beitler DM, Chung SS, Cotton PB, Gostout CJ, Hawes RH, Pasricha PJ. Transgastric endoscopic splenectomy: is it possible? Surg Endosc. 2006;20:522-525.  [PubMed]  [DOI]
60.  Park PO, Bergström M, Ikeda K, Fritscher-Ravens A, Swain P. Experimental studies of transgastric gallbladder surgery: cholecystectomy and cholecystogastric anastomosis (videos). Gastrointest Endosc. 2005;61:601-606.  [PubMed]  [DOI]
61.  Wagh MS, Merrifield BF, Thompson CC. Endoscopic transgastric abdominal exploration and organ resection: initial experience in a porcine model. Clin Gastroenterol Hepatol. 2005;3:892-896.  [PubMed]  [DOI]
62.  Swanstrom LL. Beyond endoluminal therapeutic endoscopy. Gastrointest Endosc. 2007;66:121-122.  [PubMed]  [DOI]
63.  Marescaux J, Dallemagne B, Perretta S, Wattiez A, Mutter D, Coumaros D. Surgery without scars: report of transluminal cholecystectomy in a human being. Arch Surg. 2007;142:823-826; discussion 823-826.  [PubMed]  [DOI]
64.  Fung AK, Aly EH. Systematic review of single-incision laparoscopic colonic surgery. Br J Surg. 2012;99:1353-1364.  [PubMed]  [DOI]
65.  Gaujoux S, Bretagnol F, Ferron M, Panis Y. Single-incision laparoscopic colonic surgery. Colorectal Dis. 2011;13:1066-1071.  [PubMed]  [DOI]
66.  Zhou YM, Wu LP, Zhao YF, Xu DH, Li B. Single-incision versus conventional laparoscopy for colorectal disease: a meta-analysis. Dig Dis Sci. 2012;57:2103-2112.  [PubMed]  [DOI]
67.  Mufty H, Hillewaere S, Appeltans B, Houben B. Single-incision right hemicolectomy for malignancy: a feasible technique with standard laparoscopic instrumentation. Colorectal Dis. 2012;14:e764-e770.  [PubMed]  [DOI]
68.  Fujii S, Watanabe K, Ota M, Watanabe J, Ichikawa Y, Yamagishi S, Tatsumi K, Suwa H, Kunisaki C, Taguri M. Single-incision laparoscopic surgery using colon-lifting technique for colorectal cancer: a matched case-control comparison with standard multiport laparoscopic surgery in terms of short-term results and access instrument cost. Surg Endosc. 2012;26:1403-1411.  [PubMed]  [DOI]
69.  Chen WT, Chang SC, Chiang HC, Lo WY, Jeng LB, Wu C, Ke TW. Single-incision laparoscopic versus conventional laparoscopic right hemicolectomy: a comparison of short-term surgical results. Surg Endosc. 2011;25:1887-1892.  [PubMed]  [DOI]
70.  Yang TX, Chua TC. Single-incision laparoscopic colectomy versus conventional multiport laparoscopic colectomy: a meta-analysis of comparative studies. Int J Colorectal Dis. 2013;28:89-101.  [PubMed]  [DOI]
71.  Boni L, Dionigi G, Cassinotti E, Di Giuseppe M, Diurni M, Rausei S, Cantore F, Dionigi R. Single incision laparoscopic right colectomy. Surg Endosc. 2010;24:3233-3236.  [PubMed]  [DOI]
72.  Mynster T, Hammer J, Wille-Jørgensen P. Preliminary results after single-port laparoscopic colonic surgery. Dan Med J. 2012;59:A4551.  [PubMed]  [DOI]
73.  Diana M, Dhumane P, Cahill RA, Mortensen N, Leroy J, Marescaux J. Minimal invasive single-site surgery in colorectal procedures: Current state of the art. J Minim Access Surg. 2011;7:52-60.  [PubMed]  [DOI]
74.  Chew MH, Chang MH, Tan WS, Wong MT, Tang CL. Conventional laparoscopic versus single-incision laparoscopic right hemicolectomy: a case cohort comparison of short-term outcomes in 144 consecutive cases. Surg Endosc. 2013;27:471-477.  [PubMed]  [DOI]
75.  Osborne AJ, Lim J, Gash KJ, Chaudhary B, Dixon AR. Comparison of single-incision laparoscopic high anterior resection with standard laparoscopic high anterior resection. Colorectal Dis. 2013;15:329-333.  [PubMed]  [DOI]
76.  Makino T, Milsom JW, Lee SW. Single-incision laparoscopic surgeries for colorectal diseases: early experiences of a novel surgical method. Minim Invasive Surg. 2012;2012:783074.  [PubMed]  [DOI]
77.  Kim SJ, Ryu GO, Choi BJ, Kim JG, Lee KJ, Lee SC, Oh ST. The short-term outcomes of conventional and single-port laparoscopic surgery for colorectal cancer. Ann Surg. 2011;254:933-940.  [PubMed]  [DOI]
78.  Huscher CG, Mingoli A, Sgarzini G, Mereu A, Binda B, Brachini G, Trombetta S. Standard laparoscopic versus single-incision laparoscopic colectomy for cancer: early results of a randomized prospective study. Am J Surg. 2012;204:115-120.  [PubMed]  [DOI]
79.  Maggiori L, Gaujoux S, Tribillon E, Bretagnol F, Panis Y. Single-incision laparoscopy for colorectal resection: a systematic review and meta-analysis of more than a thousand procedures. Colorectal Dis. 2012;14:e643-e654.  [PubMed]  [DOI]
80.  Wong MT, Ng KH, Ho KS, Eu KW. Single-incision laparoscopic surgery for right hemicolectomy: our initial experience with 10 cases. Tech Coloproctol. 2010;14:225-228.  [PubMed]  [DOI]
81.  Leblanc F, Champagne BJ, Augestad KM, Stein SL, Marderstein E, Reynolds HL, Delaney CP. Single incision laparoscopic colectomy: technical aspects, feasibility, and expected benefits. Diagn Ther Endosc. 2010;2010:913216.  [PubMed]  [DOI]
82.  Lu CC, Lin SE, Chung KC, Rau KM. Comparison of clinical outcome of single-incision laparoscopic surgery using a simplified access system with conventional laparoscopic surgery for malignant colorectal disease. Colorectal Dis. 2012;14:e171-e176.  [PubMed]  [DOI]
83.  Gaujoux S, Maggiori L, Bretagnol F, Ferron M, Panis Y. Safety, feasibility, and short-term outcomes of single port access colorectal surgery: a single institutional case-matched study. J Gastrointest Surg. 2012;16:629-634.  [PubMed]  [DOI]
84.  Waters JA, Guzman MJ, Fajardo AD, Selzer DJ, Wiebke EA, Robb BW, George VV. Single-port laparoscopic right hemicolectomy: a safe alternative to conventional laparoscopy. Dis Colon Rectum. 2010;53:1467-1472.  [PubMed]  [DOI]
85.  Adair J, Gromski MA, Lim RB, Nagle D. Single-incision laparoscopic right colectomy: experience with 17 consecutive cases and comparison with multiport laparoscopic right colectomy. Dis Colon Rectum. 2010;53:1549-1554.  [PubMed]  [DOI]
86.  Papaconstantinou HT, Sharp N, Thomas JS. Single-incision laparoscopic right colectomy: a case-matched comparison with standard laparoscopic and hand-assisted laparoscopic techniques. J Am Coll Surg. 2011;213:72-80; discussion 80-2.  [PubMed]  [DOI]
87.  Lee SW, Milsom JW, Nash GM. Single-incision versus multiport laparoscopic right and hand-assisted left colectomy: a case-matched comparison. Dis Colon Rectum. 2011;54:1355-1361.  [PubMed]  [DOI]
88.  McNally ME, Todd Moore B, Brown KM. Single-incision laparoscopic colectomy for malignant disease. Surg Endosc. 2011;25:3559-3565.  [PubMed]  [DOI]
89.  Wolthuis AM, Penninckx F, Fieuws S, D’Hoore A. Outcomes for case-matched single-port colectomy are comparable with conventional laparoscopic colectomy. Colorectal Dis. 2012;14:634-641.  [PubMed]  [DOI]
90.  Ramos-Valadez DI, Ragupathi M, Nieto J, Patel CB, Miller S, Pickron TB, Haas EM. Single-incision versus conventional laparoscopic sigmoid colectomy: a case-matched series. Surg Endosc. 2012;26:96-102.  [PubMed]  [DOI]
91.  Vasilakis V, Clark CE, Liasis L, Papaconstantinou HT. Noncosmetic benefits of single-incision laparoscopic sigmoid colectomy for diverticular disease: a case-matched comparison with multiport laparoscopic technique. J Surg Res. 2013;180:201-207.  [PubMed]  [DOI]
92.  Papaconstantinou HT, Thomas JS. Single-incision laparoscopic colectomy for cancer: assessment of oncologic resection and short-term outcomes in a case-matched comparison with standard laparoscopy. Surgery. 2011;150:820-827.  [PubMed]  [DOI]
93.  Lim SW, Kim HJ, Kim CH, Huh JW, Kim YJ, Kim HR. Umbilical incision laparoscopic colectomy with one additional port for colorectal cancer. Tech Coloproctol. 2013;17:193-199.  [PubMed]  [DOI]
94.  Champagne BJ, Lee EC, Leblanc F, Stein SL, Delaney CP. Single-incision vs straight laparoscopic segmental colectomy: a case-controlled study. Dis Colon Rectum. 2011;54:183-186.  [PubMed]  [DOI]
95.  Gandhi DP, Ragupathi M, Patel CB, Ramos-Valadez DI, Pickron TB, Haas EM. Single-incision versus hand-assisted laparoscopic colectomy: a case-matched series. J Gastrointest Surg. 2010;14:1875-1880.  [PubMed]  [DOI]
96.  van den Boezem PB, Sietses C. Single-incision laparoscopic colorectal surgery, experience with 50 consecutive cases. J Gastrointest Surg. 2011;15:1989-1994.  [PubMed]  [DOI]
97.  Ma J, Cassera MA, Spaun GO, Hammill CW, Hansen PD, Aliabadi-Wahle S. Randomized controlled trial comparing single-port laparoscopic cholecystectomy and four-port laparoscopic cholecystectomy. Ann Surg. 2011;254:22-27.  [PubMed]  [DOI]
98.  Phillips MS, Marks JM, Roberts K, Tacchino R, Onders R, DeNoto G, Rivas H, Islam A, Soper N, Gecelter G. Intermediate results of a prospective randomized controlled trial of traditional four-port laparoscopic cholecystectomy versus single-incision laparoscopic cholecystectomy. Surg Endosc. 2012;26:1296-1303.  [PubMed]  [DOI]
99.  Bucher P, Pugin F, Buchs NC, Ostermann S, Morel P. Randomized clinical trial of laparoendoscopic single-site versus conventional laparoscopic cholecystectomy. Br J Surg. 2011;98:1695-1702.  [PubMed]  [DOI]
100.  Rijcken E, Mennigen R, Argyris I, Senninger N, Bruewer M. Single-incision laparoscopic surgery for ileocolic resection in Crohn’s disease. Dis Colon Rectum. 2012;55:140-146.  [PubMed]  [DOI]
101.  Champagne BJ, Papaconstantinou HT, Parmar SS, Nagle DA, Young-Fadok TM, Lee EC, Delaney CP. Single-incision versus standard multiport laparoscopic colectomy: a multicenter, case-controlled comparison. Ann Surg. 2012;255:66-69.  [PubMed]  [DOI]
102.  Katsuno G, Fukunaga M, Nagakari K, Yoshikawa S, Ouchi M, Hirasaki Y. Single-incision laparoscopic colectomy for colon cancer: early experience with 31 cases. Dis Colon Rectum. 2011;54:705-710.  [PubMed]  [DOI]
103.  Uematsu D, Akiyama G, Magishi A, Nakamura J, Hotta K. Single-access laparoscopic left and right hemicolectomy combined with extracorporeal magnetic retraction. Dis Colon Rectum. 2010;53:944-948.  [PubMed]  [DOI]
104.  Poon JT, Cheung CW, Fan JK, Lo OS, Law WL. Single-incision versus conventional laparoscopic colectomy for colonic neoplasm: a randomized, controlled trial. Surg Endosc. 2012;26:2729-2734.  [PubMed]  [DOI]
105.  Makino T, Milsom JW, Lee SW. Feasibility and safety of single-incision laparoscopic colectomy: a systematic review. Ann Surg. 2012;255:667-676.  [PubMed]  [DOI]
106.  Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004;240:205-213.  [PubMed]  [DOI]
107.  Ros A, Gustafsson L, Krook H, Nordgren CE, Thorell A, Wallin G, Nilsson E. Laparoscopic cholecystectomy versus mini-laparotomy cholecystectomy: a prospective, randomized, single-blind study. Ann Surg. 2001;234:741-749.  [PubMed]  [DOI]
108.  Karthik S, Augustine AJ, Shibumon MM, Pai MV. Analysis of laparoscopic port site complications: A descriptive study. J Minim Access Surg. 2013;9:59-64.  [PubMed]  [DOI]
109.  Erdas E, Dazzi C, Secchi F, Aresu S, Pitzalis A, Barbarossa M, Garau A, Murgia A, Contu P, Licheri S. Incidence and risk factors for trocar site hernia following laparoscopic cholecystectomy: a long-term follow-up study. Hernia. 2012;16:431-437.  [PubMed]  [DOI]
110.  Lee DY, Rehmani SS, Guend H, Park K, Ross RE, Alkhalifa M, McGinty JJ, Teixeira JA. The incidence of trocar-site hernia in minimally invasive bariatric surgery: a comparison of multi versus single-port laparoscopy. Surg Endosc. 2013;27:1287-1291.  [PubMed]  [DOI]
111.  Weiss HG, Brunner W, Biebl MO, Schirnhofer J, Pimpl K, Mittermair C, Obrist C, Brunner E, Hell T. Wound complications in 1145 consecutive transumbilical single-incision laparoscopic procedures. Ann Surg. 2014;259:89-95.  [PubMed]  [DOI]
112.  Geisler D, Garrett T. Single incision laparoscopic colorectal surgery: a single surgeon experience of 102 consecutive cases. Tech Coloproctol. 2011;15:397-401.  [PubMed]  [DOI]
113.  Ross H, Steele S, Whiteford M, Lee S, Albert M, Mutch M, Rivadeneira D, Marcello P. Early multi-institution experience with single-incision laparoscopic colectomy. Dis Colon Rectum. 2011;54:187-192.  [PubMed]  [DOI]
114.  Currò G, Cogliandolo A, Lazzara S, La Malfa G, Navarra G. Single-incision versus three-port conventional laparoscopic right hemicolectomy: is there any real need to go single? J Laparoendosc Adv Surg Tech A. 2012;22:621-624.  [PubMed]  [DOI]
115.  Kehlet H. Multimodal approach to control postoperative pathophysiology and rehabilitation. Br J Anaesth. 1997;78:606-617.  [PubMed]  [DOI]
116.  Delaney CP, Brady K, Woconish D, Parmar SP, Champagne BJ. Towards optimizing perioperative colorectal care: outcomes for 1,000 consecutive laparoscopic colon procedures using enhanced recovery pathways. Am J Surg. 2012;203:353-35; discussion 353-35;.  [PubMed]  [DOI]
117.  King PM, Blazeby JM, Ewings P, Franks PJ, Longman RJ, Kendrick AH, Kipling RM, Kennedy RH. Randomized clinical trial comparing laparoscopic and open surgery for colorectal cancer within an enhanced recovery programme. Br J Surg. 2006;93:300-308.  [PubMed]  [DOI]
118.  Vlug MS, Wind J, Hollmann MW, Ubbink DT, Cense HA, Engel AF, Gerhards MF, van Wagensveld BA, van der Zaag ES, van Geloven AA. Laparoscopy in combination with fast track multimodal management is the best perioperative strategy in patients undergoing colonic surgery: a randomized clinical trial (LAFA-study). Ann Surg. 2011;254:868-875.  [PubMed]  [DOI]
119.  Kennedy RH, Francis A, Dutton S, Love S, Pearson S, Blazeby JM, Quirke P, Franks PJ, Kerr DJ. EnROL: a multicentre randomised trial of conventional versus laparoscopic surgery for colorectal cancer within an enhanced recovery programme. BMC Cancer. 2012;12:181.  [PubMed]  [DOI]
120.  Bernhardt J, Gerber B, Schober HC, Kähler G, Ludwig K. NOTES--case report of a unidirectional flexible appendectomy. Int J Colorectal Dis. 2008;23:547-550.  [PubMed]  [DOI]
121.  Palanivelu C, Rajan PS, Rangarajan M, Parthasarathi R, Senthilnathan P, Prasad M. Transvaginal endoscopic appendectomy in humans: a unique approach to NOTES--world’s first report. Surg Endosc. 2008;22:1343-1347.  [PubMed]  [DOI]
122.  Sylla P, Willingham FF, Sohn DK, Gee D, Brugge WR, Rattner DW. NOTES rectosigmoid resection using transanal endoscopic microsurgery (TEM) with transgastric endoscopic assistance: a pilot study in swine. J Gastrointest Surg. 2008;12:1717-1723.  [PubMed]  [DOI]
123.  Sylla P, Sohn DK, Cizginer S, Konuk Y, Turner BG, Gee DW, Willingham FF, Hsu M, Mino-Kenudson M, Brugge WR. Survival study of natural orifice translumenal endoscopic surgery for rectosigmoid resection using transanal endoscopic microsurgery with or without transgastric endoscopic assistance in a swine model. Surg Endosc. 2010;24:2022-2030.  [PubMed]  [DOI]
124.  Sylla P, Rattner DW, Delgado S, Lacy AM. NOTES transanal rectal cancer resection using transanal endoscopic microsurgery and laparoscopic assistance. Surg Endosc. 2010;24:1205-1210.  [PubMed]  [DOI]
125.  Leroy J, Barry BD, Melani A, Mutter D, Marescaux J. No-scar transanal total mesorectal excision: the last step to pure NOTES for colorectal surgery. JAMA Surg. 2013;148:226-30; discussion 231.  [PubMed]  [DOI]
126.  Lacy AM, Delgado S, Rojas OA, Almenara R, Blasi A, Llach J. MA-NOS radical sigmoidectomy: report of a transvaginal resection in the human. Surg Endosc. 2008;22:1717-1723.  [PubMed]  [DOI]
127.  Burghardt J, Federlein M, Müller V, Benhidjeb T, Elling D, Gellert K. [Minimal invasive transvaginal right hemicolectomy: report of the first complex NOS (natural orifice surgery) bowels operation using a hybrid approach]. Zentralbl Chir. 2008;133:574-576.  [PubMed]  [DOI]
128.  Lacy AM, Saavedra-Perez D, Bravo R, Adelsdorfer C, Aceituno M, Balust J. Minilaparoscopy-assisted natural orifice total colectomy: technical report of a minilaparoscopy-assisted transrectal resection. Surg Endosc. 2012;26:2080-2085.  [PubMed]  [DOI]
129.  Fuchs KH, Breithaupt W, Varga G, Schulz T, Reinisch A, Josipovic N. Transanal hybrid colon resection: from laparoscopy to NOTES. Surg Endosc. 2013;27:746-752.  [PubMed]  [DOI]
130.  Palanivelu C, Rangarajan M, Jategaonkar PA, Anand NV. An innovative technique for colorectal specimen retrieval: a new era of “natural orifice specimen extraction” (N.O.S.E). Dis Colon Rectum. 2008;51:1120-1124.  [PubMed]  [DOI]
131.  Karahasanoglu T, Hamzaoglu I, Aytac E, Baca B. Transvaginal assisted totally laparoscopic single-port right colectomy. J Laparoendosc Adv Surg Tech A. 2011;21:255-257.  [PubMed]  [DOI]
132.  Franklin ME, Kelley H, Kelley M, Brestan L, Portillo G, Torres J. Transvaginal extraction of the specimen after total laparoscopic right hemicolectomy with intracorporeal anastomosis. Surg Laparosc Endosc Percutan Tech. 2008;18:294-298.  [PubMed]  [DOI]
133.  Franklin ME, Liang S, Russek K. Natural orifice specimen extraction in laparoscopic colorectal surgery: transanal and transvaginal approaches. Tech Coloproctol. 2013;17 Suppl 1:S63-S67.  [PubMed]  [DOI]
134.  Franklin ME, Liang S, Russek K. Integration of transanal specimen extraction into laparoscopic anterior resection with total mesorectal excision for rectal cancer: a consecutive series of 179 patients. Surg Endosc. 2013;27:127-132.  [PubMed]  [DOI]
135.  Gaujoux S, Bretagnol F, Au J, Ferron M, Panis Y. Single port access proctectomy with total mesorectal excision and intersphincteric resection with a primary transanal approach. Colorectal Dis. 2011;13:e305-e307.  [PubMed]  [DOI]
136.  Leroy J, Diana M, Wall J, Costantino F, D’Agostino J, Marescaux J. Laparo-endoscopic single-site (LESS) with transanal natural orifice specimen extraction (NOSE) sigmoidectomy: a new step before pure colorectal natural orifices transluminal endoscopic surgery (NOTES®). J Gastrointest Surg. 2011;15:1488-1492.  [PubMed]  [DOI]
137.  Hassan I, Advani V. Single incision laparoscopic colon surgery. Is the ride worth the curve? Colorectal Dis. 2010;12:847-848.  [PubMed]  [DOI]
138.  Cianchi F, Qirici E, Trallori G, Mallardi B, Badii B, Perigli G. Single-incision laparoscopic colectomy: technical aspects and short-term results. Updates Surg. 2012;64:19-23.  [PubMed]  [DOI]
139.  Chew MH, Wong MT, Lim BY, Ng KH, Eu KW. Evaluation of current devices in single-incision laparoscopic colorectal surgery: a preliminary experience in 32 consecutive cases. World J Surg. 2011;35:873-880.  [PubMed]  [DOI]
140.  Fichera A, Zoccali M. Single-incision laparoscopic total abdominal colectomy for refractory ulcerative colitis. Surg Endosc. 2012;26:862-868.  [PubMed]  [DOI]
141.  Fichera A, Zoccali M, Felice C, Rubin DT. Total abdominal colectomy for refractory ulcerative colitis. Surgical treatment in evolution. J Gastrointest Surg. 2011;15:1909-1916.  [PubMed]  [DOI]
142.  Leblanc F, Makhija R, Champagne BJ, Delaney CP. Single incision laparoscopic total colectomy and proctocolectomy for benign disease: initial experience. Colorectal Dis. 2011;13:1290-1293.  [PubMed]  [DOI]
143.  Nagpal AP, Soni H, Haribhakti S. Hybrid Single-incision Laparoscopic Restorative Proctocolectomy with Ileal Pouch Anal Anastomosis for Ulcerative Colitis. Indian J Surg. 2010;72:400-403.  [PubMed]  [DOI]
144.  Leroy J, Cahill RA, Asakuma M, Dallemagne B, Marescaux J. Single-access laparoscopic sigmoidectomy as definitive surgical management of prior diverticulitis in a human patient. Arch Surg. 2009;144:173-19; discussion 179.  [PubMed]  [DOI]
145.  Leroy J, Costantino F, Cahill RA, Donnatelli GF, Kawai M, Hurng Sheng Wu J. Fully laparoscopic colorectal anastomosis involving percutaneous endoluminal colonic anvil control (PECAC). Surg Innov. 2010;17:79-84.  [PubMed]  [DOI]
146.  Rattner DW, Hawes R, Schwaitzberg S, Kochman M, Swanstrom L. The Second SAGES/ASGE White Paper on natural orifice transluminal endoscopic surgery: 5 years of progress. Surg Endosc. 2011;25:2441-2448.  [PubMed]  [DOI]
147.  Arezzo A, Zornig C, Mofid H, Fuchs KH, Breithaupt W, Noguera J, Kaehler G, Magdeburg R, Perretta S, Dallemagne B. The EURO-NOTES clinical registry for natural orifice transluminal endoscopic surgery: a 2-year activity report. Surg Endosc. 2013;27:3073-3084.  [PubMed]  [DOI]
148.  Meining A, Feussner H, Swain P, Yang GZ, Lehmann K, Zorron R, Meisner S, Ponsky J, Martiny H, Reddy N. Natural-orifice transluminal endoscopic surgery (NOTES) in Europe: summary of the working group reports of the Euro-NOTES meeting 2010. Endoscopy. 2011;43:140-143.  [PubMed]  [DOI]
149.  Fuchs KH, Meining A, von Renteln D, Fernandez-Esparrach G, Breithaupt W, Zornig C, Lacy A. Euro-NOTES Status Paper: from the concept to clinical practice. Surg Endosc. 2013;27:1456-1467.  [PubMed]  [DOI]
150.  Dallemagne B, Perretta S. Natural orifice transluminal endoscopic surgery (NOTES). Endoscopy. 2009;41:895-897.  [PubMed]  [DOI]
151.  Tessier C, Zhang L, Cao CG. Ergonomic considerations in natural orifice translumenal endoscopic surgery (NOTES): a case study. Work. 2012;41 Suppl 1:4683-4688.  [PubMed]  [DOI]
152.  Rolanda C, Lima E, Pêgo JM, Henriques-Coelho T, Silva D, Moreira I, Macedo G, Carvalho JL, Correia-Pinto J. Third-generation cholecystectomy by natural orifices: transgastric and transvesical combined approach (with video). Gastrointest Endosc. 2007;65:111-117.  [PubMed]  [DOI]
153.  Gumbs AA, Fowler D, Milone L, Evanko JC, Ude AO, Stevens P, Bessler M. Transvaginal natural orifice translumenal endoscopic surgery cholecystectomy: early evolution of the technique. Ann Surg. 2009;249:908-912.  [PubMed]  [DOI]
154.  Sanchez JE, Marcet JE. Colorectal natural orifice transluminal endoscopic surgery (NOTES) and transvaginal/transrectal specimen extraction. Tech Coloproctol. 2013;17 Suppl 1:S69-S73.  [PubMed]  [DOI]
155.  Linke GR, Luz S, Janczak J, Zerz A, Schmied BM, Siercks I, Warschkow R, Beutner U, Tarantino I. Evaluation of sexual function in sexually active women 1 year after transvaginal NOTES: a prospective cohort study of 106 patients. Langenbecks Arch Surg. 2013;398:139-145.  [PubMed]  [DOI]
156.  Zorron R. Natural orifice surgery applied for colorectal diseases. World J Gastrointest Surg. 2010;2:35-38.  [PubMed]  [DOI]
157.  Ohdaira T, Ikeda K, Tajiri H, Yasuda Y, Hashizume M. Usefulness of a flexible port for natural orifice transluminal endoscopic surgery by the transrectal and transvaginal routes. Diagn Ther Endosc. 2010;2010:473080.  [PubMed]  [DOI]
158.  Feussner H, Fiolka A, Schneider A, Gillen S, Kranzfelder M, Friess H, Wilhelm D. Safe sigmoid access for natural orifice transluminal endoscopic surgery (NOTES). Colorectal Dis. 2011;13 Suppl 7:55-58.  [PubMed]  [DOI]
159.  Schardey HM, Joosten U, Finke U, Staubach KH, Schauer R, Heiss A, Kooistra A, Rau HG, Nibler R, Lüdeling S. The prevention of anastomotic leakage after total gastrectomy with local decontamination. A prospective, randomized, double-blind, placebo-controlled multicenter trial. Ann Surg. 1997;225:172-180.  [PubMed]  [DOI]
160.  MacFarlane C, Vaizey CJ, Benn CA. Battle injuries of the rectum: options for the field surgeon. J R Army Med Corps. 2002;148:27-31.  [PubMed]  [DOI]
161.  Farah P, Tohme C. [War colonic wounds treated by ideal surgery. Apropos of 47 cases]. Chirurgie. 1985;111:636-640.  [PubMed]  [DOI]
162.  Keller DS, Delaney CP. Current evidence in gastrointestinal surgery: natural orifice translumenal endoscopic surgery (NOTES). J Gastrointest Surg. 2013;17:1857-1862.  [PubMed]  [DOI]
163.  Leroy J, Cahill RA, Perretta S, Forgione A, Dallemagne B, Marescaux J. Natural orifice translumenal endoscopic surgery (NOTES) applied totally to sigmoidectomy: an original technique with survival in a porcine model. Surg Endosc. 2009;23:24-30.  [PubMed]  [DOI]
164.  Park SJ, Lee KY, Choi SI, Kang BM, Huh C, Choi DH, Lee CK. Pure NOTES rectosigmoid resection: transgastric endoscopic IMA dissection and transanal rectal mobilization in animal models. J Laparoendosc Adv Surg Tech A. 2013;23:592-595.  [PubMed]  [DOI]
165.  Morino M, Verra M, Famiglietti F, Arezzo A. Natural orifice transluminal endoscopic surgery (NOTES) and colorectal cancer? Colorectal Dis. 2011;13 Suppl 7:47-50.  [PubMed]  [DOI]
166.  Telem DA, Berger DL, Bordeianou LG, Rattner DW, Sylla P. Update on Transanal NOTES for Rectal Cancer: Transitioning to Human Trials. Minim Invasive Surg. 2012;2012:287613.  [PubMed]  [DOI]
167.  Leroy J, Diana M, Barry B, Mutter D, Melani AG, Wu HS, Marescaux J. Perirectal Oncologic Gateway to Retroperitoneal Endoscopic Single-Site Surgery (PROGRESSS): a feasibility study for a new NOTES approach in a swine model. Surg Innov. 2012;19:345-352.  [PubMed]  [DOI]
168.  Arezzo A, Scozzari G, Famiglietti F, Passera R, Morino M. Is single-incision laparoscopic cholecystectomy safe? Results of a systematic review and meta-analysis. Surg Endosc. 2013;27:2293-2304.  [PubMed]  [DOI]
169.  Arezzo A, Morino M. Endoscopic surgery through single-port incision: time for a trial? Surg Endosc. 2011;25:1709-1711.  [PubMed]  [DOI]
170.  Meining A, Spaun G, Fernández-Esparrach G, Arezzo A, Wilhelm D, Martinek J, Spicak J, Feussner H, Fuchs KH, Hucl T. NOTES in Europe: summary of the working group reports of the 2012 EURO-NOTES meeting. Endoscopy. 2013;45:214-217.  [PubMed]  [DOI]