Minireviews Open Access
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Aug 27, 2021; 13(8): 834-847
Published online Aug 27, 2021. doi: 10.4240/wjgs.v13.i8.834
Robotic transanal total mesorectal excision: Is the future now?
Juan Carlos Sebastián-Tomás, Aleix Martínez-Pérez, Elías Martínez-López, Nicola de'Angelis, Marcos Gómez Ruiz, Eduardo García-Granero
Juan Carlos Sebastián-Tomás, Elías Martínez-López, Eduardo García-Granero, Department of Surgery, Universidad de Valencia, Valencia 46010, Spain
Juan Carlos Sebastián-Tomás, Elías Martínez-López, Department of General and Digestive Surgery, Hospital Universitario Doctor Peset, Valencia 46017, Spain
Aleix Martínez-Pérez, Faculty of Health Sciences, Valencian International University, Valencia 46002, Spain
Aleix Martínez-Pérez, Nicola de'Angelis, Minimally Invasive and Robotic Digestive Surgery Unit, Miulli Hospital, Acquaviva delle Fonti 70021, Italy
Marcos Gómez Ruiz, Department of General and Digestive Surgery, Hospital Universitario Marqués de Valdecilla, Santander 39008, Spain
Marcos Gómez Ruiz, Grupo de Investigación en Innovación Quirúrgica, Instituto de Investigación Biomédica Valdecilla (IDIVAL), Santander 39008, Spain
Eduardo García-Granero, Department of General and Digestive Surgery, Hospital Universitario y Politécnico la Fe, Valencia 46026, Spain
ORCID number: Juan Carlos Sebastián-Tomás (0000-0002-3149-6753); Aleix Martínez-Pérez (0000-0003-0601-932X); Elías Martínez-López (0000-0003-3516-0867); Nicola de'Angelis (0000-0002-1211-4916); Marcos Gómez Ruiz (0000-0002-0848-4682); Eduardo García-Granero (0000-0003-2657-6852).
Author contributions: Sebastián-Tomás JC, Martínez-Pérez A, and García-Granero E contributed to conception and design of the work; all authors drafted the manuscript and critical revised it for important intellectual content; all authors approve the final version.
Conflict-of-interest statement: Gómez Ruiz M received grants from Intuitive Surgical and Medtronic and currently is Medical Advisor to Intuitive Surgical, Medtronic, and Johnson & Johnson. The rest of the authors declare no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Aleix Martínez-Pérez, MD, PhD, Faculty of Health Sciences, Valencian International University, C/ Pintor Sorolla 21, Valencia 46002, Spain. aleix.martinez.perez@gmail.com
Received: February 13, 2021
Peer-review started: February 13, 2021
First decision: March 16, 2021
Revised: March 22, 2021
Accepted: July 7, 2021
Article in press: July 7, 2021
Published online: August 27, 2021

Abstract

Total mesorectal excision (TME) is the standard surgical treatment for the curative radical resection of rectal cancers. Minimally invasive TME has been gaining ground favored by the continuous technological advancements. New procedures, such as transanal TME (TaTME), have been introduced to overcome some technical limitations, especially in low rectal tumors, obese patients, and/or narrow pelvis. The earliest TaTME reports showed promising results when compared with the conventional laparoscopic TME. However, recent publications raised concerns regarding the high rates of anastomotic leaks or local recurrences observed in national series. Robotic TaTME (R-TaTME) has been proposed as a novel technique incorporating the potential benefits of a perineal dissection together with precise control of the distal margins, and also offers all those advantages provided by the robotic technology in terms of improved precision and dexterity. Encouraging short-term results have been reported for R-TaTME, but further studies are needed to assess the real role of the new technique in the long-term oncological or functional outcomes. The present review aims to provide a general overview of R-TaTME by analyzing the body of the available literature, with a special focus on the potential benefits, harms, and future perspectives for this novel approach.

Key Words: Rectal cancer, Minimally-invasive surgery, Robotics, Total mesorectal excision, Transanal approach, Natural orifice surgery

Core Tip: Rectal cancer management has been an issue of concern and discussion during the last 40 years. Total mesorectal excision (TME) has been considered the paradigm for its surgical treatment, while new minimally invasive approaches to perform TME have been introduced and expanded worldwide. Transanal TME could provide better control of the distal margins in technically complex low rectal tumors, but its oncological safety remains controversial. In this review, we discuss the current status of robotic transanal TME, including technical aspects, short- and long-term outcomes, as well as the foreseeable future marked by the improvements on robotic platforms and real-time navigation.



INTRODUCTION

Colorectal cancer (CRC) is a global health problem. Its incidence in people younger than 50 years is increasing since the mid-1990s, especially driven by the growth in rectal tumors[1]. Rectal cancer (RC) itself is the eighth most common cancer worldwide and was responsible for more than 300000 deaths in 2018[2]. Surgical resection is the primary treatment to cure rectal cancers. The proctectomy is currently included within a multidisciplinary work plan that includes exhaustive preoperative evaluation and the use of neoadjuvant therapies for locally advanced disease. The concept of total mesorectal excision (TME) was proposed by Heald et al[3] in 1982 and is widely accepted as the gold standard for RC resection. The effectiveness of a conventional trans-abdominal TME, however, may be jeopardized in some particular cases (e.g., low or extensive tumors, obese patients, etc.) increasing the odds for inadequate oncologic resections with involved distal or circumferential resection margin (CRM).

In 2010, Sylla et al[4] described a novel technique based on the natural orifice transluminal endoscopic surgery transanal endoscopic recto-sigmoid resection, by using transanal endoscopic microsurgery (TEM) with laparoscopic assistance[4]. The new approach was named transanal TME (TaTME) or “down-to-up” proctectomy. Conceptually, the TaTME seemed to facilitate the surgical treatment for mid and low RC, especially in obese or male patients with a narrow pelvis[5]. The transanal approach was supposed to provide a clearer identification of the distal tumor margin and better specimen quality than conventional up-to-down laparoscopic TME[6]. Although more than 10 years have passed since its introduction, to date no randomized controlled trial (RCT) focusing on the real effectiveness of TaTME has been published. Two ongoing RCT, the GRECCAR 11[7] and COLOR III[8] trials, are still recruiting. Therefore, the body of the current evidence is based on clinical series and retrospective comparative studies[9,10]. The difficulty to find a real standardized technique and accreditation system is also an important drawback associated with TaTME. Conventional laparoscopy is nowadays the most extensively used minimally-invasive approach for RC. Compared with open surgery, it presents benefits in terms of better intraoperative (e.g., blood loss) and postoperative clinical outcomes (e.g., earlier bowel recovery, hospital stay)[11-14], but concerns remain regarding its oncological safety[15-17]. The body of available research agrees also to reflect the disadvantages of the conventional laparoscopic instruments in complex pelvic scenarios[18].

Robotics were applied to abdominal surgery to overcome the drawbacks of standard laparoscopic procedures. The first robotic (up-to-down) TME was performed in 2006 by Pigazzi et al[19]. During the past few years, and due to the continuous improvement in the platforms, robotics gained popularity with promising expectancies. The main benefit, when compared with the conventional laparoscopic approach, seems to be a reduction in the conversion rates to open surgery[20]. However, even though robotic assistance seems to facilitate the mesorectal dissection, no clear benefits have been shown to date in terms of oncologic and functional outcomes[21,22]. Robotic technology has been also applied to transanal procedures. First, robotic transanal minimally invasive surgery (R-TAMIS) has been used to resect small polyps or to perform rectal-preserving excisions of early neoplasms[23]. When compared with conventional TAMIS (C-TAMIS), R-TAMIS increases the chance of resecting difficult rectal lesions and facilitates the closure of the rectal defects, with similar postoperative and pathological outcomes but increased costs (3562 dollars for C-TAMIS vs 4441 dollars for R-TAMIS, P = 0.04)[24]. Robotic transanal mesorectal excision (R-TaTME) is a recent alternative for TME that allows to resect entirely the rectum from below, combining potential benefits and indications of robotics and TaTME. Few publications have appeared to date focusing on those new procedures, but some reporting has shown encouraging clinical and oncological results[25-38].

The present review aims to offer a detailed description of the current status of R-TaTME, with an emphasis on the perioperative outcomes and the near future perspectives.

TECHNOLOGICAL BACKGROUND

TEM was first reported by Buess et al[39,40] in the 1980s. TEM showed acceptable postoperative and oncological outcomes for polyps or early tumors located 5 to 20 cm from the anal verge[41]. However, the procedures were technically challenging and associated with a non-despicable learning curve, therefore the expansion of TEM was limited for many years. To overcome these difficulties, TAMIS was developed in 2009 by Atallah et al[42]. Although it was originally described using standard laparoscopic instruments, robotic-assistance for TAMIS was soon implemented in a cadaveric model[43]. In 2012, the first R-TAMIS for a local excision was performed[44]. Three years after the first TaTME[4], the first R-TaTME was successfully performed in humans[25]. The patient was obese with familial adenomatous polyposis diagnosed with synchronous hepatic flexure and RCs. The abdominal resection was done by a conventional laparoscopic approach. The TaTME was performed using a Da Vinci Si® robot transanally, with a GelPOINT® Platform as an interface. The specimen obtained presented a nearly-complete mesorectal quality and tumor-free margins[25].

The ever-expanding technological developments that continue to shape our world today have brought several possibilities to improve the limitations of the current diagnostic and therapeutic tools, especially minimally-invasive interventional procedures. R-TAMIS was first performed using the da Vinci® Surgical System (Intuitive Surgical, Sunnyvale, CA, United States)[44]. The novel application was supposed to overcome the main limitations of C-TAMIS and TEM, using endo-wristed instruments to enhance dexterity and precision. After the first published R-TaTME[25], many other studies have demonstrated the effectiveness of the following platform’s evolution, the Vinci® Surgical System-Si[25,29-33,35,38]. The latest Vinci® robotic system was introduced in 2014. The da Vinci® Xi similarly has been found useful to perform R-TaTME[34,37]. The technical improvements introduced in the latest generation provided several advantages, especially regarding versatility in docking and thinner instruments.

Two main R-TaTME procedures can be distinguished: (1) Totally-robotic TaTME (TR-TaTME), in which the abdominal part is also performed by a robotic approach[27]; and (2) Robotic-assisted TaTME (RA-TaTME), in which the abdominal part is performed by conventional laparoscopy or open surgery (hybrid procedures)[25].

The GelPOINT® Platform (Applied Medical, Rancho Santa Margarita, CA, United States) is the most frequently used interface. This port was specifically designed for transanal surgery and offers sphincter protection by a rigid access channel. Gómez-Ruiz et al[29] developed a platform by using a PAT proctoscopy (PAT, Developia-HUMV), which was placed transanally after lumen occlusion, then fixed to the table. A GelPOINT® Platform occluded the proctoscopy and allowed trocar placement[29]. This platform was a hybrid between TEM and TAMIS, with some reusable components. Complete technical details provided by the literature are displayed in Table 1.

Table 1 Technical details of the series reporting robotic transanal total mesorectal excision.
Ref.
Period of study
n
Robotic platform
Transanal interface
Patients' position
Type of Robotic TaTME
Teams
Remarks
Atallah et al[25], 201311da Vinci SiGelPOINT pathDorsal lithotomyRobotic-assisted11st robotic TaTME
Verheijen et al[26], 20141da VinciGelPOINT pathLithotomyRobotic-assisted1
Gómez Ruiz et al[29], 2015August 2013 January 20145da Vinci SiTransanalLithotomyTotally robotic11st totally robotic TaTME
Access Port +
GelPOINT
Atallah et al[30], 2015November 2011 August 20144da Vinci SiGelPOINT pathDorsal lithotomyRobotic-assisted1
Atallah et al[31], 20151da Vinci SiGelPOINT + LonestarDorsal lithotomyRobotic-assisted21st robotic ISR + TaTME
Huscher et al[32], 2015January 2014 April 20147da Vinci SiGelPOINT pathRobotic-assisted1
Kuo et al[33], 2017July 2015 March 201615da Vinci SiGelPOINT pathLithotomy 15º trendelenburgTotally robotic1Robotic SSPO
Hu et al[34], 2020January 2016 November 201620daVinci XiGelPOINT pathLithotomyRobotic-assisted2
Monsellato et al[35], 2019May 2017 October 20173da Vinci SiGelPOINT pathDorsal lithotomyRobotic-assisted1 (2)
2 (1)
Tan et al[36], 2020September 20191Robotic-assisted2Laparoscopic SSPO
Suhardja et al[37], 20201da Vinci XiLone Star +Lloyd-DaviesTotally robotic1
GelPOINT path
Ye et al[38], 2021May 2017 January 202013da Vinci SiSTARport pathLithotomy trendelenburgTotally robotic (9)1 (9)
Robotic-assisted (4)2 (4)
Hybrid TaTME

Two teams reported hybrid procedures with robotic-assistance during the abdominal phase combined with a conventional TaTME[45,46]. Both reported similar outcomes to those obtained with R-TaTME. Bravo et al[45] performed the abdominal and the transanal resections simultaneously. Nikolic et al[46] published 8 cases, with one anastomotic leak and one presacral abscess managed conservatively. In all the patients, a complete TME with free CRM and distal margins was obtained. Samalavicius et al[47] reported a successful case of hybrid TaTME with robotic TME and pure transanal resection, using the Senhance® Transenterix robotic system. The postoperative course and the histologic report were both uneventful.

BENEFITS AND LIMITATIONS

Preoperative evaluation and adequate staging are essential for a proper selection of the surgical technique and the approach when we face RC. In this sense, imaging evaluation with magnetic resonance imaging of the pelvis, the possibility of neoadjuvant treatment with radiochemotherapy in locally advanced cases, and multidisciplinary team discussion about each patient are pivotal[38]. The major benefits of R-TaTME are expected in male, obese patients, with a narrow pelvis and/or a tumor distance to anal verge lower than 8 cm.

When performing R-TaTME, both the transanal and the abdominal phases can be theoretically benefited with the incorporation of robotic assistance. Robotic technology can provide a more precise dissection following the oncological planes, then avoiding damaging the adjacent structures. Three-dimensional high-definition imaging with a stable camera view, or enhanced movement’s freedom with tremor control, would help to perform a purse-string suture or increase the chances of controlling unexpected bleeding[34]. Beyond these advantages, a subjective feeling of conducting a higher quality TME has been reported during the robotic dissection[32]. The transanal approach, per se, allows better control of the distal margin at the beginning of the procedure. Moreover, the robotics system confers additional advantages as improving ambidexterity at lateral dissection or providing surgical fields steadier compared with the traditional techniques[34]. The reduction of the angular restriction in the narrow pelvic space also facilitates the preservation of the pelvic nerves and their autonomic function[38]. For some authors, additionally, there was a subjective synergistic effect by incorporating robotics into both phases of the surgery[33].

Increased expenditures and limited access for most surgeons worldwide are the intrinsic limitations attributed to the use of robotics in surgery, becoming the greatest anchor for the widespread of technology. Cost-analysis studies determined that robotic surgery was more expensive than open and laparoscopic surgeries for CRC[48,49]. In robotic rectal surgery, the ROLARR trial showed that the costs in the robotic-assisted laparoscopic group (11853 pounds or 13668 dollars) were higher than those in the conventional laparoscopic group (10874 pounds or 12556 dollars)[21]. Regarding robotic transanal surgery, Atallah et al[28] reported an increased cost of 1500 dollars per case, including the GelPOINT® Platform. The use of another laparoscopic system is supposed to increase the costs[38]. However, it can be expected that reducing procedural times with simultaneous two-field interventions or using new (hopefully cheaper) robotic platforms may mitigate the economic burden and make robotic surgery more accessible. Additionally, robotic digestive surgery is noteworthy, far from being yet fully developed.

Technical drawbacks are still important. The da Vinci® Si required a minimum inter-trocar distance higher than 8 cm[38]. When using the new da Vinci Xi together with the GelPOINT® Platform during the transanal phase, reaching the peritoneal reflection from below is hampered[34]. Finally, two-field simultaneous robotic interventions continue under development and are not still implemented in the normal clinical practice[50,51]. A learning curve is unavoidable for any new procedure. Robotic surgery requires special training and the development of new skills. Indeed, at least 20-23 cases are needed to achieve expertise in robotic TME[52]. On the other hand, TaTME is a complex and technically demanding technique. Its learning-curve has not been yet fully established but has been estimated in around 40 cases[53]. Therefore, all the published experience was performed by surgeons in the learning period of R-TaTME, even if they were well-trained and skilled experts in robotic and laparoscopic surgery. In the future, structured training courses will be fundamental to shorten the learning curve. The industry should be also encouraged to continue innovating surgical technologies towards the same end.

SURGICAL OUTCOMES

In the present review, we identified 11 case reports or clinical series describing 71 R-TaTME procedures[26,29-38]. The earliest reports by Atallah et al[25,28] and Gómez Ruiz et al[27] were further included in larger series (Table 2)

Table 2 Demographic and preoperative data, n (%).
Ref.
n
Male/female
Age (yr)
BMI (kg/m2)
Tumor DAV (cm)
Clinical stage (I/II/III/IV)
Neoadjuvant treatment
Type
Verheijen et al[26], 201410/1 (100)4823.680/0/1/01 (100)CRT
Gómez Ruiz et al[29], 201554 (80)/1 (20)57 ± 13.9125.8 ± 2.715 (4-6)21/0/4/04 (80)CRT
Atallah et al[30], 201543 (75)/1 (25)44 (26-59)229 (21-38)21/0/3/03 (75)CRT
Atallah et al[31], 201511 (100)/06631.6< 0.431/0/0/00
Huscher et al[32], 201573 (42.9)/4 (57.1)63.2 ± 9.7129.9 ± 6.112 (1–6.5)45/2/0/00
Kuo et al[33], 2017157 (46.7)/8 (53.3)60.3 (44–75)421.973.3 (2.0–5.0)411 (73.3)CRT
Hu et al[34], 20202013 (65)/7 (35)56.3 ± 14.4123.9 ± 3.415.8 ± 2.614/4/10/212 (60)CRT 9 (45)RT 3 (15)
Monsellato et al[35], 201932 (66.6)/1 (33.3)61 (55–68)226 (25–28)24.33 (3-6)20/0/3/03 (100)CRT
Tan et al[36], 202011 (100)/07124.0830/0/1/01 (100)CT
Suhardja et al[37], 202011 (100)/06760/0/1/01 (100)CRT
Ye et al[38], 2021139 (69.2)/4 (30.8)62 (42- 67)522.26 (20.90–24.08)54.5 (4- 6)51/2/10/011 (84.6)CRT
Intraoperative outcomes

Robotic TME may decrease the conversion rates to open surgery when compared with conventional laparoscopic TME[20-22]. Although there were no conversions from R-TaTME to open surgery in the published cases or series, Kuo et al[33] reported two conversions towards a conventional five-port laparoscopy. Operative time ranged between 132 min and 530 min[35,36]. The largest series included 20 patients, and both interventions were performed simultaneously, with a mean operative time of 172.3 ± 24.2 min[34]. In three of the studies, the transanal phase was faster than the abdominal[32,37,38]. Operative time tended to be higher in the TR-TaTME series, maybe because both phases were not run simultaneously[29,33,38]. Blood loss was lower than 100 mL. in most of the cases[29,31,33,34,36,38]. Intraoperative complications were reported in 2 cases: (1) Hu et al[34] reported one case of presacral surface bleeding solved without conversion to open surgery; and (2) A left-ureter section that was inadvertently encompassed within the linear stapler during vessel transection. This was related to inadequate anterior traction of the vascular bundle caused by limitations in movement of the Da Vinci® Si robotic arms. The incident was identified and repaired intraoperatively[33]. The majority of patients received a diverting stoma during the index surgery (Table 3).

Table 3 Intraoperative and postoperative outcomes, n (%).
Ref.
OT, min     
TransanalOT, min
Abdominal OT, min
Blood loss, mL
Splenic flexure mobilization
Transanal specimen extraction
Defunctioning stoma
Anastomosis method (H/S/E)1
Anastomosis height (n)
Intraoperative complications
Conversion
Postoperative complications
Length of stay, d
Mortality
Verheijen et al[26], 20142056550Yes1 (100)1 (100)100%/0%/0%ColorectalNoNoNo30%
Gómez Ruiz et al[29], 2015398 ± 882123 ± 502112 ± 27290 ± 502Yes5 (100)5 (100)40%/60%/0%Coloanal (2); Colorectal (3)NoNo1 (20)6 ± 120%
Atallah et al[30], 2015376 (140-409)3200 (50-300)3Yes3 (75)75%/0%/25%Coloanal (3)NoNo3 (75)4.3 (4-5)30%
Atallah et al[31], 2015316751 (100)100%/0%/0%Coloanal (1)NoNoNo0%
Huscher et al[32], 2015165.7 ± 54.4255.5 ± 12.42Yes7 (100)7 (100)0%/100%/0%Coloanal (7)NoNo1 (14.29)4.8 ± 0.620%
Kuo et al[33], 20167473 (335–569)433 (30–50)415 (100)5 (33.3)100%/0%/0%Coloanal (15)1 (6.7)2 (13.3) to laparoscopic2 (13.3)12.2 ± 1.520%
Hu et al[34], 2020172.3 ± 24.2282.0 ± 107.12Yes (25)L-colostomy 6 (30); L-ileostomy 8 (40)10%/80%/10%Coloanal (2); Colorectal (16)1 (5)No7 (35)8.8 ± 4.220%
Monsellato et al[35], 2019530 (440–600)3InconsistentYes3 (100)3 (100)100%/0%/0%Coloanal (3)NoNoNo10.6 (7-15)30%
Tan et al[36], 202013220NoNoNo60%
Suhardja et al[37], 202021050160No1 (100)0%/100%/0%Colorectal (1)NoNoNo50%
Ye et al[38], 2021240 (195–270)595 (74–100)560 (50–100)5Yes13 (100)12 (92.3)61.5%/38.5%/0%Coloanal (9); Colorectal (4)NoNo3 (23.1)7 (6–10)50%
Postoperative outcomes

Six series reported postoperative complications[29,30,32-34,38]. Two grade B anastomotic leaks were described, both successfully treated conservatively[29,38]. A third patient was diagnosed with a pelvic abscess treated with antibiotics[34]. Postoperative ileus (n = 2), duodenal bleeding (n = 2), and rectal bleeding (n = 1) were the other remarkable postoperative complications[32,34,38]. Two patients required surgical reoperation: (1) Laparoscopic adhesiolysis for postoperative intestinal obstruction; and (2) Wound bleeding requiring surgical hemostasis[33,41]. Postoperative complications were described on 17/71 (29.94%) patients (Table 4). Length of hospital stay ranged between 4.3 d and 14 d[30,35]. There was no postoperative mortality.

Table 4 Detail of postoperative complications.
Ref.

Gómez Ruiz et al[29], 2015Grade B anastomotic leak diagnosed in the outpatient clinic on postoperative day 14
Atallah et al[30], 2015Sub-segmental pulmonary embolism
Dehydration related to high output from his diverting ileostomy that required readmission 3 wk postoperatively
Wound hematoma requiring drainage 2 wk postoperatively
Huscher et al[32], 2015Rectal bleeding requiring the transfusion of blood units without reoperation
Kuo et al[33], 2017Laparoscopic adhesiolysis for postoperative intestinal obstruction
Superficial wound infection
Hu et al[34], 2020Postoperative Ileus with Conservative treatment
Pelvic abscess treated with antibiotics
Acute urinary retention that required reinsertion of Foley catheter
Perineal wound bleeding that needed hemostasis
Duodenal ulcer bleeding with conservative treatment
Fever with unknown origin with conservative treatment
Acute appendicitis managed with antibiotics
Ye et al[38], 2021Anastomotic leakage grade B on postoperative day 3History of duodenal ulcer with duodenal hemorrhage on postoperative day 7 solved with conservative treatment
Postoperative ileus treated with gastrointestinal decompression and parenteral nutrition
Pathologic outcomes

Maybe the most important single potential benefit of robotic assistance in colorectal surgery is to facilitate mesorectal dissection, particularly in complex mid and low rectal tumors. This may reduce the rates of positive CRM. A combination with the precise control of the distal margins provided by a transanal dissection is then extremely promising. There were no distal margin involvements in the literature, but Hu et al[34] reported 3 positive CRM. Two cases were thought to be due to initial T4 lesions that, despite size reduction after neoadjuvant treatment, still retained residual viable microscopic cancer cells. The third was thought to be secondary to a metastatic lymph node located less than 1 mm from the CRM. The authors discussed that all of them were related to the original disease and not directly to the surgical procedure. A complete TME has become a critical oncologic factor to predict tumor recurrence in the pelvis[54,55]. The quality of TME was reported as near-complete (n = 12) in four series[30,32,34,38]. This reflects a 17.1% rate for non-optimal TME quality, which may appear to be higher than initially expected. The number of lymph nodes harvested ranged between 12 and 33 (Table 5).

Table 5 Pathologic, oncological, and functional outcomes.
Ref.
Tumor size, cm
Quality TME (I/II/III), %
CRM +
Distal margin +
Harvested nodes
DAV, cm      
CRM, cm
Follow-up, mo
Local recurrence
Distant progression, m
Functional (urinary/sexual)
Verheijen et al[26], 2014100/0/0NoNo2
Gómez Ruiz et al[29], 2015100/0/0NoNo14 ± 911.8 (1-2.5)23 (3)2No
Atallah et al[30], 20152.7 (1.5-3.5)225/75/0NoNo27 (15-39)33.3 (1-5)38 (6-12)3NoNo
Atallah et al[31], 20153100/0/0NoNo330.4
Huscher et al[32], 201585.7/14.3/0NoNo14 ± 312.7 ± 213.2 ± 1.812.5 (2–3.5)2
Kuo et al[33], 2017100/0/0NoNo12 (8-18)31.4 (0.4–3.5)30.7 (0.2-2.6)3
Hu et al[34], 20203.3 ± 1.5190/10/03 (15)No18.7 ± 6.312.9 ± 1.310.88 ± 0.7811 (5) 18 m 1 (5) 7
Monsellato et al[35], 2019100/0/0NoNo12 (12)NoNo
Tan et al[36], 20207NoNo
Suhardja et al[37], 2020100/0/0NoNo2412NoNoNo
Ye et al[38], 20213 (2–4)461.5/38.5/0NoNo15 (13-16)42 (1.5–2.5)415 (11–18)4NoNo
Long-term oncologic and Functional outcomes

None of the published studies adequately addressed the mid- or long-term oncological results. The longest median follow-up was only 15 (range 11-18) mo[38]. Hu et al[34] identified a local recurrence after 1.5 years. Distant metastatic disease was documented in a patient who developed liver metastases 7 mo postoperatively[34]. On the other hand, the functional outcomes and the quality of life remain essentially unexplored since only Suhardja et al[37] described no urinary or sexual dysfunction in a patient after 12 mo of follow-up.

FUTURE PERSPECTIVES
TaTME controversy

TaTME was introduced by Sylla et al[4] in 2010 to overcome the challenges of resecting a low RC. TaTME popularity rapidly grew. Great benefits were expected for the technique due to the enhanced ergonomics and exposition of the rectal anatomy and the adjacent structures. These improvements were supposed to have an impact demonstrated by lower rates of conversion or postoperative complications, or by greater chances to perform a successful oncologic resection. The results from the most important international TaTME registry, however, showed high rates of anastomotic failure. Urethral injuries and carbon dioxide embolisms were found also to be potentially severe complications during TaTME[56]. Moreover, in a recent meta-analysis, the TaTME also failed to show any significant improvement in the functional outcomes compared with the conventional laparoscopic TME[57]. To add insult to injury, the Norwegian TaTME Collaborative Group recently reported frightening data, warning the whole surgical community. They reported higher rates of anastomotic leak in TaTME patients compared with those included in NoRGast study (8.4 vs 4.5, P = 0.047) and higher local recurrence rates (7.6%), some of them with an atypical multifocal pattern of presentation. According to these findings, TaTME for RC was suspended in Norway. Future studies are expected to clarify the shadows around TaTME. GRECCAR 11[7] and COLOR III[8] RCTs results are expected soon. In this scenario, we agree with the recommendation to wait for the RCTs that will provide the required evidence either to support definitively or reject TaTME[58]. The RESET trial is also ongoing to evaluate all the surgical approaches currently used for low anterior resection plus TME in a specific subgroup of high-risk patients[59].

New robotic platforms

Technological progression is moving ahead at a staggering speed. The da Vinci® system was alone at the forefront of the sector, but for years now new platforms are being developed, some of them with a special focus on single-port and natural orifice surgery. First, it is worth noting the latest evolution of the da Vinci® robotic platform. The da Vinci® SP™ Surgical System promises some advantages such as the possibility of three working instruments with flexion. After an initial evaluation for RATS[60], Kneist et al[61] showed that single-port access for R-TaTME was technically feasible with the robot in both surgical fields, performing the intervention in a male human cadaver. It is expected to achieve soon the Food and Drug Administration approval for colorectal procedures. The Flex® Robotic System with CR (colorectal) Drive (MedRobotics, Corp. Raynham, MA, United States) was also successfully implemented in a cadaveric model[62]. However, the flexible effector arms were not robotic-assisted, and the design of the platform does not allow a safe dissection in the distal rectum. The SPORT™ Surgical System (Titan Medical, Toronto, Canada) is under development with promising applications in general, colorectal, urologic, and gynecologic surgery. Although not used transanally, the Senhance® robotic system has been proposed as an alternative for the abdominal phase of a hybrid TaTME in humans[47].

Two-field surgery

The transanal dissection adds the possibility for two teams to work simultaneously. Although the combination of laparoscopic and robotic approaches has been described for RA-TaTME, robotic surgeons and industry engineers have not previously considered a two-field, dual-console robotic system as the ideal for TR-TaTME. Now, the da Vinci® Xi platform allows the use of a robotic camera in the transanal field together with a laparoscopic one, to be viewed by both console surgeons using software and hardware interfacing (TilePro®)[50]. The main limitation is the maximum of four arms in the Xi platform, which also needs a camera to be assigned to one, leaving then one surgeon to work with a single instrument. Recently, Versius Robotic Surgical System (CMR Surgical, Inc., Cambridge, United Kingdom) was proposed as an alternative to enable two-field robotic surgery in preclinical conditions[51]. The possibility to work simultaneously is thought to reduce the operative time and consequently the overall procedural costs. The Food and Drug Administration approval is expected.

Real-time navigation

Navigation may be useful for R-TaTME to enhance the precision of the movements and to fully understand the complex anatomies[63]. Blueprint for R-TaTME navigation was described by combining the da Vinci Xi® Surgical System and the Stryker Navigation System, with the GelPOINT® Platform[64]. More recently, real-time stereotactic navigation with the da Vinci® Xi platform via the TilePro® interface has been reported[65]. In this study, fluorescence-guided surgery was also used for structure localization by using indocyanine green in the ureters and at the tumor site. Although many limitations remain to be solved, real-time navigation and fluorescence-guided surgery appear to be the next steps in the evolution of robotics and digital surgery.

CONCLUSION

Robotic TaTME has been introduced as a novel technique, with the potential benefits of both TaTME and robotic technology. This combination may overcome the limitations of the conventional laparoscopic TME and also mitigate some of the concerns attributed to the conventional TaTME. However, the available experience for R-TaTME is still limited. To date, this operation has been performed only in small groups of selected patients. Moreover, no team has reported data regarding the long-term follow-up. Preliminary results should be interpreted with caution and well-designed comparative studies are needed to give the green light to this promising approach. Critical aspects, as the real value of the procedure and its impact on the learning curve, have not been addressed yet. The evolution of the new robotic platforms and the chances provided by two-field surgery and real-time intraoperative navigation are the cornerstones for the success and future expansion of R-TaTME.

Footnotes

Manuscript source: Invited manuscript

Corresponding Author's Membership in Professional Societies: Spanish Society of Surgeons; European Association of Endoscopic Surgeons; and World Society of Emergency Surgery.

Specialty type: Surgery

Country/Territory of origin: Spain

Peer-review report’s scientific quality classification

Grade A (Excellent): 0

Grade B (Very good): B, B, B, B

Grade C (Good): C, C

Grade D (Fair): 0

Grade E (Poor): 0

P-Reviewer: Ammendola M, Tong WD, Wang J, Zhang W S-Editor: Liu M L-Editor: Filipodia P-Editor: Li JH

References
1.  Siegel RL, Miller KD, Goding Sauer A, Fedewa SA, Butterly LF, Anderson JC, Cercek A, Smith RA, Jemal A. Colorectal cancer statistics, 2020. CA Cancer J Clin. 2020;70:145-164.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 690]  [Cited by in F6Publishing: 570]  [Article Influence: 690.0]  [Reference Citation Analysis (0)]
2.  Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68:394-424.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 28752]  [Cited by in F6Publishing: 23868]  [Article Influence: 9584.0]  [Reference Citation Analysis (0)]
3.  Heald RJ, Husband EM, Ryall RD. The mesorectum in rectal cancer surgery--the clue to pelvic recurrence? Br J Surg. 1982;69:613-616.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1782]  [Cited by in F6Publishing: 1295]  [Article Influence: 45.7]  [Reference Citation Analysis (0)]
4.  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]  [Cited in This Article: ]  [Cited by in Crossref: 438]  [Cited by in F6Publishing: 286]  [Article Influence: 39.8]  [Reference Citation Analysis (0)]
5.  Fernández-Hevia M, Delgado S, Castells A, Tasende M, Momblan D, Díaz del Gobbo G, DeLacy B, Balust J, Lacy AM. Transanal total mesorectal excision in rectal cancer: short-term outcomes in comparison with laparoscopic surgery. Ann Surg. 2015;261:221-227.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 199]  [Cited by in F6Publishing: 71]  [Article Influence: 33.2]  [Reference Citation Analysis (0)]
6.  Emile SH, de Lacy FB, Keller DS, Martin-Perez B, Alrawi S, Lacy AM, Chand M. Evolution of transanal total mesorectal excision for rectal cancer: From top to bottom. World J Gastrointest Surg. 2018;10:28-39.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 22]  [Cited by in F6Publishing: 14]  [Article Influence: 7.3]  [Reference Citation Analysis (0)]
7.  Lelong B, de Chaisemartin C, Meillat H, Cournier S, Boher JM, Genre D, Karoui M, Tuech JJ, Delpero JR;  French Research Group of Rectal Cancer Surgery (GRECCAR). A multicentre randomised controlled trial to evaluate the efficacy, morbidity and functional outcome of endoscopic transanal proctectomy versus laparoscopic proctectomy for low-lying rectal cancer (ETAP-GRECCAR 11 TRIAL): rationale and design. BMC Cancer. 2017;17:253.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 50]  [Cited by in F6Publishing: 38]  [Article Influence: 12.5]  [Reference Citation Analysis (0)]
8.  Deijen CL, Velthuis S, Tsai A, Mavroveli S, de Lange-de Klerk ES, Sietses C, Tuynman JB, Lacy AM, Hanna GB, Bonjer HJ. COLOR III: a multicentre randomised clinical trial comparing transanal TME versus laparoscopic TME for mid and low rectal cancer. Surg Endosc. 2016;30:3210-3215.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 185]  [Cited by in F6Publishing: 133]  [Article Influence: 30.8]  [Reference Citation Analysis (0)]
9.  Lacy AM, Tasende MM, Delgado S, Fernandez-Hevia M, Jimenez M, De Lacy B, Castells A, Bravo R, Wexner SD, Heald RJ. Transanal Total Mesorectal Excision for Rectal Cancer: Outcomes after 140 Patients. J Am Coll Surg. 2015;221:415-423.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 204]  [Cited by in F6Publishing: 139]  [Article Influence: 34.0]  [Reference Citation Analysis (0)]
10.  Aubert M, Mege D, Panis Y. Total mesorectal excision for low and middle rectal cancer: laparoscopic versus transanal approach-a meta-analysis. Surg Endosc. 2020;34:3908-3919.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 18]  [Cited by in F6Publishing: 19]  [Article Influence: 9.0]  [Reference Citation Analysis (0)]
11.  van der Pas MH, Haglind E, Cuesta MA, Fürst A, Lacy AM, Hop WC, Bonjer HJ;  COlorectal cancer Laparoscopic or Open Resection II (COLOR II) Study Group. Laparoscopic versus open surgery for rectal cancer (COLOR II): short-term outcomes of a randomised, phase 3 trial. Lancet Oncol. 2013;14:210-218.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 886]  [Cited by in F6Publishing: 324]  [Article Influence: 110.8]  [Reference Citation Analysis (0)]
12.  Kang SB, Park JW, Jeong SY, Nam BH, Choi HS, Kim DW, Lim SB, Lee TG, Kim DY, Kim JS, Chang HJ, Lee HS, Kim SY, Jung KH, Hong YS, Kim JH, Sohn DK, Kim DH, Oh JH. Open versus laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy (COREAN trial): short-term outcomes of an open-label randomised controlled trial. Lancet Oncol. 2010;11:637-645.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 620]  [Cited by in F6Publishing: 244]  [Article Influence: 56.4]  [Reference Citation Analysis (0)]
13.  Guillou PJ, Quirke P, Thorpe H, Walker J, Jayne DG, Smith AM, Heath RM, Brown JM;  MRC CLASICC trial group. 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]  [Cited in This Article: ]  [Cited by in Crossref: 2159]  [Cited by in F6Publishing: 741]  [Article Influence: 134.9]  [Reference Citation Analysis (0)]
14.  Martínez-Pérez A, Carra MC, Brunetti F, de'Angelis N. Short-term clinical outcomes of laparoscopic vs open rectal excision for rectal cancer: A systematic review and meta-analysis. World J Gastroenterol. 2017;23:7906-7916.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 20]  [Cited by in F6Publishing: 15]  [Article Influence: 6.7]  [Reference Citation Analysis (0)]
15.  Fleshman J, Branda M, Sargent DJ, Boller AM, George V, Abbas M, Peters WR Jr, Maun D, Chang G, Herline A, Fichera A, Mutch M, Wexner S, Whiteford M, Marks J, Birnbaum E, Margolin D, Larson D, Marcello P, Posner M, Read T, Monson J, Wren SM, Pisters PW, Nelson H. Effect of Laparoscopic-Assisted Resection vs Open Resection of Stage II or III Rectal Cancer on Pathologic Outcomes: The ACOSOG Z6051 Randomized Clinical Trial. JAMA. 2015;314:1346-1355.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 586]  [Cited by in F6Publishing: 405]  [Article Influence: 97.7]  [Reference Citation Analysis (0)]
16.  Stevenson AR, Solomon MJ, Lumley JW, Hewett P, Clouston AD, Gebski VJ, Davies L, Wilson K, Hague W, Simes J;  ALaCaRT Investigators. Effect of Laparoscopic-Assisted Resection vs Open Resection on Pathological Outcomes in Rectal Cancer: The ALaCaRT Randomized Clinical Trial. JAMA. 2015;314:1356-1363.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 547]  [Cited by in F6Publishing: 368]  [Article Influence: 91.2]  [Reference Citation Analysis (0)]
17.  Martínez-Pérez A, Carra MC, Brunetti F, de'Angelis N. Pathologic Outcomes of Laparoscopic vs Open Mesorectal Excision for Rectal Cancer: A Systematic Review and Meta-analysis. JAMA Surg. 2017;152:e165665.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 87]  [Cited by in F6Publishing: 70]  [Article Influence: 21.8]  [Reference Citation Analysis (0)]
18.  Hong JSY, Brown KGM, Waller J, Young CJ, Solomon MJ. The role of MRI pelvimetry in predicting technical difficulty and outcomes of open and minimally invasive total mesorectal excision: a systematic review. Tech Coloproctol. 2020;10: 991-1000..  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 6]  [Article Influence: 5.0]  [Reference Citation Analysis (0)]
19.  Pigazzi A, Ellenhorn JD, Ballantyne GH, Paz IB. Robotic-assisted laparoscopic low anterior resection with total mesorectal excision for rectal cancer. Surg Endosc. 2006;20:1521-1525.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 246]  [Cited by in F6Publishing: 177]  [Article Influence: 16.4]  [Reference Citation Analysis (0)]
20.  Corrigan N, Marshall H, Croft J, Copeland J, Jayne D, Brown J. Exploring and adjusting for potential learning effects in ROLARR: a randomised controlled trial comparing robotic-assisted vs. standard laparoscopic surgery for rectal cancer resection. Trials. 2018;19:339.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 32]  [Cited by in F6Publishing: 17]  [Article Influence: 10.7]  [Reference Citation Analysis (0)]
21.  Jayne D, Pigazzi A, Marshall H, Croft J, Corrigan N, Copeland J, Quirke P, West N, Rautio T, Thomassen N, Tilney H, Gudgeon M, Bianchi PP, Edlin R, Hulme C, Brown J. Effect of Robotic-Assisted vs Conventional Laparoscopic Surgery on Risk of Conversion to Open Laparotomy Among Patients Undergoing Resection for Rectal Cancer: The ROLARR Randomized Clinical Trial. JAMA. 2017;318:1569-1580.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 437]  [Cited by in F6Publishing: 257]  [Article Influence: 109.3]  [Reference Citation Analysis (0)]
22.  Prete FP, Pezzolla A, Prete F, Testini M, Marzaioli R, Patriti A, Jimenez-Rodriguez RM, Gurrado A, Strippoli GFM. Robotic Versus Laparoscopic Minimally Invasive Surgery for Rectal Cancer: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Ann Surg. 2018;267:1034-1046.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 123]  [Cited by in F6Publishing: 40]  [Article Influence: 61.5]  [Reference Citation Analysis (0)]
23.  Tomassi MJ, Taller J, Yuhan R, Ruan JH, Klaristenfeld DD. Robotic Transanal Minimally Invasive Surgery for the Excision of Rectal Neoplasia: Clinical Experience With 58 Consecutive Patients. Dis Colon Rectum. 2019;62:279-285.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 23]  [Cited by in F6Publishing: 7]  [Article Influence: 11.5]  [Reference Citation Analysis (0)]
24.  Lee SG, Russ AJ, Casillas MA Jr. Laparoscopic transanal minimally invasive surgery (L-TAMIS) versus robotic TAMIS (R-TAMIS): short-term outcomes and costs of a comparative study. Surg Endosc. 2019;33:1981-1987.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 15]  [Cited by in F6Publishing: 9]  [Article Influence: 5.0]  [Reference Citation Analysis (0)]
25.  Atallah S, Nassif G, Polavarapu H, deBeche-Adams T, Ouyang J, Albert M, Larach S. Robotic-assisted transanal surgery for total mesorectal excision (RATS-TME): a description of a novel surgical approach with video demonstration. Tech Coloproctol. 2013;17:441-447.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 64]  [Cited by in F6Publishing: 46]  [Article Influence: 8.0]  [Reference Citation Analysis (0)]
26.  Verheijen PM, Consten EC, Broeders IA. Robotic transanal total mesorectal excision for rectal cancer: experience with a first case. Int J Med Robot. 2014;10:423-426.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 34]  [Cited by in F6Publishing: 26]  [Article Influence: 4.9]  [Reference Citation Analysis (0)]
27.  Gómez Ruiz M, Palazuelos CM, Martín Parra JI, Alonso Martín J, Cagigas Fernández C, del Castillo Diego J, Gómez Fleitas M. New technique of transanal proctectomy with completely robotic total mesorrectal excision for rectal cancer. Cir Esp. 2014;92:356-361.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 17]  [Cited by in F6Publishing: 10]  [Article Influence: 2.4]  [Reference Citation Analysis (0)]
28.  Atallah S, Martin-Perez B, Pinan J, Quinteros F, Schoonyoung H, Albert M, Larach S. Robotic transanal total mesorectal excision: a pilot study. Tech Coloproctol. 2014;18:1047-1053.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 51]  [Cited by in F6Publishing: 37]  [Article Influence: 7.3]  [Reference Citation Analysis (0)]
29.  Gómez Ruiz M, Parra IM, Palazuelos CM, Martín JA, Fernández CC, Diego JC, Fleitas MG. Robotic-assisted laparoscopic transanal total mesorectal excision for rectal cancer: a prospective pilot study. Dis Colon Rectum. 2015;58:145-153.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 57]  [Cited by in F6Publishing: 26]  [Article Influence: 9.5]  [Reference Citation Analysis (0)]
30.  Atallah S, Martin-Perez B, Parra-Davila E, deBeche-Adams T, Nassif G, Albert M, Larach S. Robotic transanal surgery for local excision of rectal neoplasia, transanal total mesorectal excision, and repair of complex fistulae: clinical experience with the first 18 cases at a single institution. Tech Coloproctol. 2015;19:401-410.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 33]  [Cited by in F6Publishing: 21]  [Article Influence: 5.5]  [Reference Citation Analysis (0)]
31.  Atallah S, Drake J, Martin-Perez B, Kang C, Larach S. Robotic transanal total mesorectal excision with intersphincteric dissection for extreme distal rectal cancer: a video demonstration. Tech Coloproctol. 2015;19:435.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 10]  [Cited by in F6Publishing: 4]  [Article Influence: 1.7]  [Reference Citation Analysis (0)]
32.  Huscher CG, Bretagnol F, Ponzano C. Robotic-assisted transanal total mesorectal excision: the key against the Achilles' heel of rectal cancer? Ann Surg. 2015;261:e120-e121.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 14]  [Article Influence: 5.2]  [Reference Citation Analysis (0)]
33.  Kuo LJ, Ngu JC, Tong YS, Chen CC. Combined robotic transanal total mesorectal excision (R-taTME) and single-site plus one-port (R-SSPO) technique for ultra-low rectal surgery-initial experience with a new operation approach. Int J Colorectal Dis. 2017;32:249-254.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 19]  [Article Influence: 6.2]  [Reference Citation Analysis (0)]
34.  Hu JM, Chu CH, Jiang JK, Lai YL, Huang IP, Cheng AY, Yang SH, Chen CC. Robotic transanal total mesorectal excision assisted by laparoscopic transabdominal approach: A preliminary twenty-case series report. Asian J Surg. 2020;43:330-338.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 3]  [Cited by in F6Publishing: 3]  [Article Influence: 1.5]  [Reference Citation Analysis (0)]
35.  Monsellato I, Morello A, Prati M, Argenio G, Piscioneri D, Lenti LM, Priora F. Robotic transanal total mesorectal excision: A new perspective for low rectal cancer treatment. A case series. Int J Surg Case Rep. 2019;61:86-90.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 4]  [Cited by in F6Publishing: 3]  [Article Influence: 2.0]  [Reference Citation Analysis (0)]
36.  Tan DW, Zhang F, Ye JW, Liu ZY, Ke ZG, Li R, Tong WD, Li F. [Initial report of laparoscopic single incision plus one port with simultaneous robotic-assisted transanal total mesorectal excision for low rectal cancer surgery]. Zhonghua Wei Chang Wai Ke Za Zhi. 2020;23:605-609.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in F6Publishing: 1]  [Reference Citation Analysis (0)]
37.  Suhardja TS, Smart PJ, Heriot AG, Warrier SK. Total robotic transabdominal and transanal total mesorectal excision - a video vignette. Colorectal Dis. 2020;22:1798-1799.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1]  [Cited by in F6Publishing: 1]  [Article Influence: 1.0]  [Reference Citation Analysis (0)]
38.  Ye J, Shen H, Li F, Tian Y, Gao Y, Zhao S, Liu B, Tong W. Robotic-assisted transanal total mesorectal excision for rectal cancer: technique and results from a single institution. Tech Coloproctol. 2021;25:693-700.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 6]  [Article Influence: 5.0]  [Reference Citation Analysis (0)]
39.  Buess G, Hutterer F, Theiss J, Böbel M, Isselhard W, Pichlmaier H. [A system for a transanal endoscopic rectum operation]. Chirurg. 1984;55:677-680.  [PubMed]  [DOI]  [Cited in This Article: ]
40.  Buess G, Kipfmüller K, Hack D, Grüssner R, Heintz A, Junginger T. Technique of transanal endoscopic microsurgery. Surg Endosc. 1988;2:71-75.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 163]  [Cited by in F6Publishing: 40]  [Article Influence: 4.9]  [Reference Citation Analysis (0)]
41.  Allaix ME, Arezzo A, Caldart M, Festa F, Morino M. Transanal endoscopic microsurgery for rectal neoplasms: experience of 300 consecutive cases. Dis Colon Rectum. 2009;52:1831-1836.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 92]  [Cited by in F6Publishing: 32]  [Article Influence: 8.4]  [Reference Citation Analysis (0)]
42.  Atallah S, Albert M, Larach S. Transanal minimally invasive surgery: a giant leap forward. Surg Endosc. 2010;24:2200-2205.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 348]  [Cited by in F6Publishing: 236]  [Article Influence: 31.6]  [Reference Citation Analysis (0)]
43.  Atallah SB, Albert MR, deBeche-Adams TH, Larach SW. Robotic TransAnal Minimally Invasive Surgery in a cadaveric model. Tech Coloproctol. 2011;15:461-464.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 72]  [Cited by in F6Publishing: 50]  [Article Influence: 7.2]  [Reference Citation Analysis (0)]
44.  Atallah S, Parra-Davila E, DeBeche-Adams T, Albert M, Larach S. Excision of a rectal neoplasm using robotic transanal surgery (RTS): a description of the technique. Tech Coloproctol. 2012;16:389-392.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 58]  [Cited by in F6Publishing: 39]  [Article Influence: 6.4]  [Reference Citation Analysis (0)]
45.  Bravo R, Trépanier JS, Arroyave MC, Fernández-Hevia M, Pigazzi A, Lacy AM. Combined transanal total mesorectal excision (taTME) with laparoscopic instruments and abdominal robotic surgery in rectal cancer. Tech Coloproctol. 2017;21:233-235.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 11]  [Cited by in F6Publishing: 6]  [Article Influence: 2.8]  [Reference Citation Analysis (0)]
46.  Nikolic A, Waters PS, Peacock O, Choi CC, Rajkomar A, Heriot AG, Smart P, Warrier S. Hybrid abdominal robotic approach with conventional transanal total mesorectal excision (TaTME) for rectal cancer: feasibility and outcomes from a single institution. J Robot Surg. 2020;14:633-641.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 6]  [Cited by in F6Publishing: 4]  [Article Influence: 3.0]  [Reference Citation Analysis (0)]
47.  Samalavicius NE, Janusonis V, Smolskas E, Dulskas A. Transanal and robotic total mesorectal excision (robotic-assisted TaTME) using the Senhance® robotic system - a video vignette. Colorectal Dis. 2020;22:114-115.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 4]  [Article Influence: 2.5]  [Reference Citation Analysis (0)]
48.  Bertani E, Chiappa A, Biffi R, Bianchi PP, Radice D, Branchi V, Cenderelli E, Vetrano I, Cenciarelli S, Andreoni B. Assessing appropriateness for elective colorectal cancer surgery: clinical, oncological, and quality-of-life short-term outcomes employing different treatment approaches. Int J Colorectal Dis. 2011;26:1317-1327.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 45]  [Cited by in F6Publishing: 40]  [Article Influence: 4.5]  [Reference Citation Analysis (0)]
49.  Baek SJ, Kim SH, Cho JS, Shin JW, Kim J. Robotic versus conventional laparoscopic surgery for rectal cancer: a cost analysis from a single institute in Korea. World J Surg. 2012;36:2722-2729.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 101]  [Cited by in F6Publishing: 76]  [Article Influence: 12.6]  [Reference Citation Analysis (0)]
50.  Atallah S, DuBose A, Larach SW. Towards the development of simultaneous two-field robotic surgery. Tech Coloproctol. 2016;20:71-73.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 5]  [Article Influence: 0.8]  [Reference Citation Analysis (0)]
51.  Atallah S, Parra-Davila E, Melani AGF. Assessment of the Versius surgical robotic system for dual-field synchronous transanal total mesorectal excision (taTME) in a preclinical model: will tomorrow's surgical robots promise newfound options? Tech Coloproctol. 2019;23:471-477.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 18]  [Cited by in F6Publishing: 12]  [Article Influence: 9.0]  [Reference Citation Analysis (0)]
52.  Jiménez-Rodríguez RM, Rubio-Dorado-Manzanares M, Díaz-Pavón JM, Reyes-Díaz ML, Vazquez-Monchul JM, Garcia-Cabrera AM, Padillo J, De la Portilla F. Learning curve in robotic rectal cancer surgery: current state of affairs. Int J Colorectal Dis. 2016;31:1807-1815.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 51]  [Cited by in F6Publishing: 33]  [Article Influence: 10.2]  [Reference Citation Analysis (0)]
53.  Rickard MJFX. Transanal total mesorectal excision: 10 years on - time to stop and re-think. ANZ J Surg. 2020;90:654-655.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 3]  [Cited by in F6Publishing: 3]  [Article Influence: 3.0]  [Reference Citation Analysis (0)]
54.  Martínez-Pérez A, de'Angelis N. Oncologic results of conventional laparoscopic TME: is the intramesorectal plane really acceptable? Tech Coloproctol. 2018;22:831-834.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2]  [Cited by in F6Publishing: 1]  [Article Influence: 0.7]  [Reference Citation Analysis (0)]
55.  García-Granero E, Faiz O, Muñoz E, Flor B, Navarro S, Faus C, García-Botello SA, Lledó S, Cervantes A. Macroscopic assessment of mesorectal excision in rectal cancer: a useful tool for improving quality control in a multidisciplinary team. Cancer. 2009;115:3400-3411.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 67]  [Cited by in F6Publishing: 52]  [Article Influence: 5.6]  [Reference Citation Analysis (0)]
56.  Penna M, Hompes R, Arnold S, Wynn G, Austin R, Warusavitarne J, Moran B, Hanna GB, Mortensen NJ, Tekkis PP;  International TaTME Registry Collaborative. Incidence and Risk Factors for Anastomotic Failure in 1594 Patients Treated by Transanal Total Mesorectal Excision: Results From the International TaTME Registry. Ann Surg. 2019;269:700-711.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 134]  [Cited by in F6Publishing: 40]  [Article Influence: 134.0]  [Reference Citation Analysis (0)]
57.  van der Heijden JAG, Koëter T, Smits LJH, Sietses C, Tuynman JB, Maaskant-Braat AJG, Klarenbeek BR, de Wilt JHW. Functional complaints and quality of life after transanal total mesorectal excision: a meta-analysis. Br J Surg. 2020;107:489-498.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 20]  [Cited by in F6Publishing: 15]  [Article Influence: 20.0]  [Reference Citation Analysis (0)]
58.  Caycedo-Marulanda A, Patel S, Merchant S, Brown C. Introduction of new techniques and technologies in surgery: Where is transanal total mesorectal excision today? World J Gastrointest Surg. 2020;12:203-207.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in CrossRef: 2]  [Cited by in F6Publishing: 2]  [Article Influence: 2.0]  [Reference Citation Analysis (0)]
59.  Rouanet P, Gourgou S, Gogenur I, Jayne D, Ulrich A, Rautio T, Spinoglio G, Bouazza N, Moussion A, Gomez Ruiz M. Rectal Surgery Evaluation Trial: protocol for a parallel cohort trial of outcomes using surgical techniques for total mesorectal excision with low anterior resection in high-risk rectal cancer patients. Colorectal Dis. 2019;21:516-522.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 9]  [Cited by in F6Publishing: 7]  [Article Influence: 4.5]  [Reference Citation Analysis (0)]
60.  Marks J, Ng S, Mak T. Robotic transanal surgery (RTAS) with utilization of a next-generation single-port system: a cadaveric feasibility study. Tech Coloproctol. 2017;21:541-545.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 31]  [Cited by in F6Publishing: 19]  [Article Influence: 7.8]  [Reference Citation Analysis (0)]
61.  Kneist W, Stein H, Rheinwald M. Da Vinci Single-Port robot-assisted transanal mesorectal excision: a promising preclinical experience. Surg Endosc. 2020;34:3232-3235.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 9]  [Cited by in F6Publishing: 6]  [Article Influence: 9.0]  [Reference Citation Analysis (0)]
62.  Atallah S, Hodges A, Larach SW. Direct target NOTES: prospective applications for next generation robotic platforms. Tech Coloproctol. 2018;22:363-371.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 24]  [Cited by in F6Publishing: 12]  [Article Influence: 8.0]  [Reference Citation Analysis (0)]
63.  Franchini Melani AG, Diana M, Marescaux J. The quest for precision in transanal total mesorectal excision. Tech Coloproctol. 2016;20:11-18.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 21]  [Cited by in F6Publishing: 16]  [Article Influence: 3.5]  [Reference Citation Analysis (0)]
64.  Atallah S, Zenoni S, Kelly J, Tilahun Y, Monson JR. A blueprint for robotic navigation: pre-clinical simulation for transanal total mesorectal excision (taTME). Tech Coloproctol. 2016;20:653-654.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 7]  [Cited by in F6Publishing: 5]  [Article Influence: 1.4]  [Reference Citation Analysis (0)]
65.  Atallah S, Parra-Davila E, Melani AGF, Romagnolo LG, Larach SW, Marescaux J. Robotic-assisted stereotactic real-time navigation: initial clinical experience and feasibility for rectal cancer surgery. Tech Coloproctol. 2019;23:53-63.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 13]  [Cited by in F6Publishing: 11]  [Article Influence: 6.5]  [Reference Citation Analysis (0)]