Laparoscopic surgery for rectal cancer remains challenging because of limited joint motion during dissection in the deep and narrow pelvis. Handheld multiarticulated instruments have been developed to address these limitations. This study aimed to assess the safety and efficacy of a flexible articulated instrument, the ArtiSential® (Livsmed Co, Korea), at reducing the duration of laparoscopic rectal cancer surgery.

We retrospectively reviewed patients who underwent laparoscopic low or ultralow anterior resection for primary mid to low rectal cancer (tumor distance from anal verge, ≤ 10 cm) performed by a single surgeon in 2012-2022. Patients were divided into groups based on the use of ArtiSential® or straight device, and their clinical characteristics, surgical procedures, pathological findings, postoperative complications, and survival outcomes were analyzed.

The study included 93 patients (articulating group, 32; straight group, 61). Low anterior resection was predominant in both groups, while operative time was significantly shorter in the articulating group (148.08 ± 49.72 vs. 188.13 ± 57.86; p = 0.003). Total mesorectal excision quality and resection margin status did not differ between groups. Postoperative complications, including anastomotic leakage, length of hospital stay, 3-year recurrence-free survival rate (90.6% vs. 88.5%, p = 0.760), and overall survival rate (100% vs. 85.2%, p = 0.092), did not differ between groups.

Use of the flexible articulated instrument (ArtiSential®) can reduce operative time without impairing surgical quality or oncologic outcomes. These results suggest that laparoscopic rectal cancer surgery can be performed safely and effectively using a flexible articulated instrument.

Not applicable.

The role of laparoscopy in rectal cancer surgery has evolved considerably since the early 2000s. Initial randomized trials, such as COLOR II and COREAN, indicated that laparoscopic approaches offered similar pathological outcomes with better postoperative recovery than open surgery. In contrast, trials like ACOSOG Z6051 and ALaCaRT suggested noninferiority could not be established. Variability in trial outcomes, focusing on either disease-free survival or pathological measures, initially hindered consensus. Long-term analyses have shown no significant difference in disease-free survival between laparoscopic and open approaches. Meta-analyses have reinforced the benefits of laparoscopic surgery, with reduced mortality and similar oncologic effectiveness to open surgery. However, new techniques like transanal TME (TaTME) and robotic approaches have introduced alternatives, though each presents unique challenges, from recurrence rates in TaTME to costs in robotics. While laparoscopy remains the preferred method due to accessibility and outcomes, robotic surgery is expected to gain traction in high-volume centers.

To analyze and compare the application and efficacy of side-to-side anastomosis and end-to-end anastomosis in natural orifice specimen extraction surgery (NOSES) NOSES operation for left colon cancer.

A retrospective analysis of 69 patients in our hospital from February 2018 to February 2022 who underwent NOSES for left colon tumors. The observation group was performed with side-to-side anastomosis (Overlap). For digestive tract reconstruction, the control group was anastomosed by end-to-end anastomosis; the intraoperative and postoperative conditions and complications were compared between the two groups.

There was no significant difference in operation time and intraoperative blood loss between the two groups (P > 0.05). However, the intraoperative anastomosis time in the observation group was significantly shorter than that in the control group (P < 0.001). Additionally, there was no significant difference in the time of first exhaustion, defecation time, degree of patency of defecation, frequency of defecation, postoperative hospital stays and postoperative pain between the two groups (P > 0.05). Furthermore, the overall incidence of postoperative complications did not show a significant difference (P > 0.05).

In the NOSES surgery of left colon cancer, both side-to-side anastomosis (Overlap) and end-to-end anastomosis yielded comparable intraoperative and postoperative conditions and complications, but the side-to-side anastomosis (Overlap) method was simpler operation-wise and had a shorter intraoperative anastomosis time. As such, this method is the preferred anastomosis method when NOSES for colorectal cancer is carried out in primary hospitals.

ChiCTR1900026104 (2019-09-21).

Local resection (LR) in rectal cancer is indicated in stage T1N0M0 without unfavorable pathological factors, achieving oncologically satisfactory outcomes through transanal endoscopic surgery techniques. However, the initial step involves accurate staging and selection of these tumors through specific tests conducted in specialized colorectal units. For T2N0M0 tumors and T1 tumors with poor prognostic factors, the standard treatment is total mesorectal excision (TME), a procedure associated with high postoperative morbidity and mortality, functional impairments, and reduced quality of life. Therefore, new organ-preservation strategies are being explored as alternatives to TME. These include neoadjuvant therapy combined with LR, which has shown promising results, and neoadjuvant therapy followed by a "Watch and Wait" approach -where patients with complete clinical response are selected for strict surveillance- as an ideal future treatment, although there are still current challenges to be addressed.

This study aims to examine why we encounter a pathological circumferential resection margin (pCRM)-positive specimen whose preoperative MRI indicates negative mesorectal fascia involvement in middle to low rectal cancer.

Forty-four consecutive patients included in this study had c(yc)T1-3 primary rectal adenocarcinoma without mesorectal fascia involvement and underwent laparoscopic total mesorectal excision (TME) with curative intent in the Department of Gastrointestinal Surgery of Kansai Medical University Hospital from January 2014 to April 2018. We adopted three checkpoints to investigate the misleading point causing positive pCRM (≤ 1 mm). (1) c(yc)CRM diagnosis by two radiologists with more than 20 and 15 years of experience in rectal cancer MRI diagnosis. (2) The specimen was assessed using the TME score presented by Nagtegaal. (3) We compared the standard sectioning according to UK guidelines (group A; n = 26) with the specimen MRI image navigation-based section (group B; n = 18) in terms of estimation of pCRM by c(yc)CRM.

We achieved a "complete" resection specimen in all cases. A simple correlation coefficient in group B revealed a significant correlation between c(yc)CRM and pCRM (r = 0.663, p = 0.00513); this correlation was not significant in group A (r = 0.261, p = 0.19824). However, tests for differences between linear regression coefficients in groups A and B showed no significant differences (p = 0.12596). There were five cases of pCRM ≤ 1 mm: three in group A and two in group B. An anterior lesion caused pCRM ≤ 1 mm in three cases; the tumor deposits or extramural vascular invasion caused the other cases.

The cause of misleading pCRM was the inaccurate preoperative MRI diagnosis of c(yc)CRM.

These days, various surgical techniques such as trans-anal, trans-perineal total mesorectal excision, and transvaginal natural orifice transluminal endoscopic surgery have been utilized with flexibility, which was not possible before the laparoscopic era.

From January 2014 to January 2023, 40 cases of c(yc)T4b rectal cancer underwent local curative surgery laparoscopically at Kansai Medical University Hospital. In 25 consecutive cases, we adopted multiple approaches (trans-anal total mesorectal excision, transvaginal natural orifice transluminal endoscopic surgery, trans-perineal total mesorectal excision, or prone position first abdominoperineal excision) to remove the deepest part of the tumor indicated by MRI last as the specimen-oriented surgery. The remaining 15 patients underwent top-to-bottom surgery based on standard surgery. The primary endpoint was the local recurrence rate of the specimen-oriented surgery group compared to that of the standard surgery group.

The specimen-oriented surgery group had a median follow-up of 3.9 (0.4-7.4) years with no local recurrence, while the standard surgery group had a median follow-up of 1.5 (0.7-3.7) years with 5 of 15 patients (33%) experiencing more local recurrence than specimen-oriented surgery group (p = 0.005). Comparison of the local recurrence ( +) and ( -) groups showed significant differences in pCRM positive rate, neoadjuvant therapy, tumor size, and approach (specimen-oriented surgery vs. standard surgery) in univariate analysis (p < 0.05). Still, no significant differences were found in the multivariate analysis.

In the laparoscopic setting, local cure of c(yc)T4b rectal cancer requires a different strategy than open surgery, and specimen-oriented surgery may be a promising procedure.

Previous studies have demonstrated the advantages of short-term histopathological outcomes and complications associated with transanal total mesorectal excision (TME) compared with laparoscopic TME. However, the long-term oncological outcomes of transanal TME remain ambiguous. This study aims to compare 3-year disease-free survival of transanal TME with laparoscopic TME.

To evaluate 3-year disease-free survival between transanal TME and laparoscopic TME in patients with rectal cancer.

This randomized, open-label, noninferiority, phase 3 clinical trial was performed in 16 different centers in China. Between April 2016 and June 2021, a total of 1115 patients with clinical stage I to III mid-low rectal cancer were enrolled. The last date of participant follow-up was in June 2024.

Participants were randomly assigned in a 1:1 ratio before their surgical procedure to undergo either transanal TME (n = 558) or laparoscopic TME (n = 557).

The primary end point was 3-year disease-free survival, with a noninferiority margin of -10% for the comparison between transanal TME and laparoscopic TME. Secondary outcomes included 3-year overall survival and 3-year local recurrence.

In the primary analysis set, the median patient age was 60 years. A total of 692 male and 397 female patients were included in the analysis. Three-year disease-free survival was 82.1% (97.5% CI, 78.4%-85.8%) for the transanal TME group and 79.4% (97.5% CI, 75.6%-83.4%) for the laparoscopic TME group, with a difference of 2.7% (97.5% CI, -3.0% to 8.1%). The lower tail of a 2-tailed 97.5% CI for the group difference in 3-year disease-free survival was above the noninferiority margin of -10 percentage points. Furthermore, the 3-year local recurrence was 3.6% (95% CI, 2.0%-5.1%) for transanal TME and 4.4% (95% CI, 2.6%-6.1%) for laparoscopic TME. Three-year overall survival was 92.6% (95% CI, 90.4%-94.8%) for transanal TME and 90.7% (95% CI, 88.3%-93.2%) for laparoscopic TME.

In patients with mid-low rectal cancer, 3-year disease-free survival for transanal TME was noninferior to that of laparoscopic TME.

ClinicalTrials.gov Identifier: NCT02966483.

Over the past two decades, minimally invasive approaches in rectal surgery have changed the landscape of surgical interventions, impacting both malignant and benign pathologies. The dynamic nature of rectal cancer treatment owes much to innovations in surgical techniques, reflected in the expanding literature on available treatment modalities. Local excision, facilitated by minimally invasive surgery, offers curative potential for patients with early T1 rectal cancers and favorable pathologic features. For more complex cases, laparoscopic and robotic surgery have demonstrated significant efficacy and provided precise, durable outcomes while reducing perioperative morbidity and enhancing postoperative recovery. Additionally, advancements in imaging, surgical instrumentation, and enhanced recovery protocols have further optimized patient care. The integration of multidisciplinary care has also emerged as a cornerstone of treatment, emphasizing collaboration among surgeons, oncologists, and radiologists to deliver personalized, evidence-based care. This narrative review aims to elucidate current minimally invasive surgical techniques and approaches for rectal pathologies, spanning benign and malignant conditions, while also exploring future directions in the field, including the potential role of artificial intelligence and next-generation robotic platforms.

With the continuous development of laparoscopic techniques in recent years, laparoscopic total mesorectal excision (LapTME) and laparoscopic-assisted transanal total mesorectal excision (TaTME) have gradually become important surgical techniques for treating low-lying rectal cancer (LRC). However, there is still controversy over the efficacy and safety of these two surgical modalities in LRC treatment.

To compare the efficacy of LapTME vs TaTME in patients with LRC.

Ninety-four patients with LRC who visited and were treated at the Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital between December 2022 and March 2024 were selected and divided into the LapTME (n = 44) and TaTME (n = 50) groups. Clinical operation indexes, postoperative recovery indicators, and postoperative complications were recorded. The anal resting pressure (ARP), anal maximum systolic pressure (MSP), and maximum tolerated volume (MTV) of the anal canal were also measured. The intestinal function of patients was evaluated by the Memorial Sloan Kettering Cancer Center (MSKCC) bowel function questionnaire. Serum norepinephrine (NE), adrenaline (AD), and cortisol (Cor) levels were measured. The Quality of Life Questionnaire Core 30 (QLQ-C30) was used for quality of life assessment.

Compared with the LapTME group, the surgery time in the TaTME group was longer; intraoperative blood loss was low; time of anal exhaust, first postoperative ambulation, intestinal recovery, and hospital stay were shorter; and the distal incisal margin and specimen lengths were longer. The TaTME group also showed higher ARP, MSP, and MTV values and higher MSKCC and QLQ-C30 scores than the LapTME group 3 months postoperatively. Cor, AD, and NE levels were lower in the TaTME group than those in the LapTME group during recovery.

We demonstrated that TaTME better improved anal function, reduced postoperative stress, and accelerated postoperative recovery and, hence, was safer for patients with LRC.

Transanal total mesorectal excision (TaTME) is a promising and innovative approach for lower rectal cancer but requires high technical skill and learning process that can affect patient outcomes. We aimed to determine the learning curve of TaTME and then to assess its impact on 5-year oncologic outcomes.

Over a 54-month period, 94 patients underwent TaTME by experienced laparoscopic colorectal surgeons at our department. To provide a comprehensive overview of success, we used a composite criterion including the most relevant parameters related to the learning process: the conversion rate to an open procedure, TaTME procedure completion, severe postoperative morbidity, mesorectal integrity on macroscopic evaluation, and microscopic margins. Moving average method and cumulative sum analyses were performed.

The operative time continuously decreased over the entire study period. The success rate stabilised after 14 patients in a parallel and balanced analysis of the two surgeons' experiences. Mesorectal completeness was the most sensitive marker for the TaTME learning process (42.9% vs 71.25%; p = 0.06). The learning process did not significantly affect the postoperative morbidity, conversion rate, or R0 resection. Five-year oncological outcomes were similar between the groups.

Even among laparoscopically experienced surgeons, the TaTME learning process influences the oncological quality of the resection but not the postoperative morbidity. Gaining an early command of the surgical anatomy and technical skills and understanding the challenges through specific educational sessions are necessary. The results of this study could help generate a comprehensive training program and define necessary prerequisites for prospective trials.

This study is registered in our Clinical Research Unit (2016_LELONG_01). Our database is registered in the clinicalTrials.gov registry: Institut Paoli Calmettes Colorectal Cancer Database (NCT02869503).

Pivotal articles that had been published between 2022 and 2023 on surgical and perioperative adjuvant treatments for locally advanced colorectal cancer (CRC) were reviewed. This review focuses on new evidence in the following areas: optimization of surgical procedures for colon cancer, including the optimal length of bowel resection and use of the no-touch isolation technique; minimally invasive surgery for rectal cancer, such as laparoscopic transanal total mesorectal excision and robotic surgery; neoadjuvant treatments for rectal cancer, including total neoadjuvant therapy; neoadjuvant chemotherapy for colon cancer; and postoperative adjuvant chemotherapy for Stage II and III colon cancer. Although the current understanding may not enable perfect decision-making for patients and medical professionals, ongoing advancements are expected to result in more effective personalized treatment plans, ultimately improving the prognosis and quality of life of patients.

Textbook outcome has been incorporated into quality assessment measures in various oncological settings; however, it has not been applied to patients with low rectal cancer after neoadjuvant chemoradiotherapy (nCRT). This study aimed to examine the prevalence and predictors of achieving a textbook outcome in patients undergoing surgical resection of low rectal cancer after nCRT.

This study was a post hoc subgroup analysis of the prospective multicentric LASRE trial, which specifically enrolled patients with rectal cancer located within 5 cm from the dentate line at diagnosis, tumors with diameters less than 6 cm, and patients who underwent radical laparoscopic or open resection. A total of 597 patients who had clinically staged cT3-4aN0-2M0 tumors with diameters less than 6 cm and who underwent neoadjuvant chemoradiotherapy followed by radical resection were included.

Textbook outcome was achieved in 60.0 % of patients. Multivariate logistic regression analysis revealed that body mass index >25 kg/m2 (OR = 0.594, P = 0.01), tumor distance from the anal verge >40 mm (OR = 5.518, P < 0.001), operative time >202 min (OR = 0.675, P = 0.04), and laparoscopic approach (OR = 1.497, P = 0.04) were independently predictive factors for the achievement of a textbook outcome in low rectal cancer patients undergoing nCRT and radical resection. A predictive nomogram for achieving a textbook outcome was constructed, yielding a C-index of 0.727.

Laparoscopic resection exhibited promising potential in improving the probability of achieving a textbook outcome.

This study aimed to review the historical transition of rectal cancer surgery and recent evidence regarding transanal total mesorectal excision (TaTME). Additionally, it outlined the anatomical landmarks and technical considerations essential for successful TaTME. Anatomical studies and surgical techniques were analyzed to identify key landmarks and procedural steps crucial for TaTME. TaTME offers improved visibility and maneuverability even in the deep and narrow pelvis and is expected to contribute to tumor radical cure rates. By securing the circumferential resection margin and distal margin while preserving pelvic autonomic nerve function, TaTME holds promise for maintaining postoperative urinary and sexual functions. Key anatomical landmarks include the endopelvic fascia posteriorly, the S4-pelvic splanchnic nerve laterally, and the prostate or posterior vaginal wall anteriorly. Selecting the appropriate dissection layer based on tumor depth and ensuring precise incision of the tendinous arch of the pelvic fascia contributes to successful TaTME outcomes. TaTME represents a significant advancement in rectal cancer surgery, offering improved outcomes through meticulous attention to anatomical detail and precise dissection techniques. Understanding the historical context of rectal cancer surgery alongside recent evidence on TaTME is essential for optimizing patient outcomes and expanding the safe implementation of this innovative approach.

Total mesorectal excision (TME) has greatly improved rectal cancer surgery outcomes by reducing local recurrence and enhancing patient survival. This review outlines essential knowledge and techniques for performing TME. TME emphasizes the complete resection of the mesorectum along embryologic planes to minimize recurrence. Key anatomical insights include understanding the rectal proper fascia, Denonvilliers fascia, rectosacral fascia, and the pelvic autonomic nerves. Technical tips cover a step-by-step approach to pelvic dissection, the Gate approach, and tailored excision of Denonvilliers fascia, focusing on preserving pelvic autonomic nerves and ensuring negative circumferential resection margins. In Korea, TME has led to significant improvements in local recurrence rates and survival with well-adopted multidisciplinary approaches. Surgical techniques of TME have been optimized and standardized over several decades in Korea, and minimally invasive surgery for TME has been rapidly and successfully adopted. The review emphasizes the need for continuous research on tumor biology and precise surgical techniques to further improve rectal cancer management. The ultimate goal of TME is to achieve curative resection and function preservation, thereby enhancing the patient's quality of life. Accurate TME, multidisciplinary-based neoadjuvant therapy, refined sphincter-preserving techniques, and ongoing tumor research are essential for optimal treatment outcomes.

Purpose: To investigate the clinical value of the bacterial culture of fluid in the surgical area in laparoscopic transanal total mesorectal excision (Lap-taTME) and laparoscopic total mesorectal excision (Lap-TME). Methods: Clinical data of 106 patients with rectal cancer who had undergone surgery were retrospectively collected, including 56 patients in the Lap-taTME group and 50 patients in the Lap-TME group. In the Lap-taTME group, the initial pelvic fluid, the rectal cavity fluid after purse-string suture, and the pelvic cavity fluid after anastomosis were collected and recorded as culture No. 1, No. 2, and No. 3, respectively. In the Lap-TME group, culture No. 1 and No. 3 were collected as done in the Lap-taTME group. The culture results and postoperative complications were statistically analyzed. Results: The positive rate of culture No. 1 was zero in both groups, and there were 6 cases (10.7%) with positive culture No. 2 in the Lap-taTME group. However, the number of patients with positive culture No. 3 (7, 12.5%) and cumulative positive culture cases (11, 19.6%) in the Lap-taTME group were significantly higher than those in the Lap-TME group (0) (all P < .05). Pelvic infection occurred in 4 (7.1%) of the 11 cases (19.6%) with positive culture in the Lap-taTME group, accounting for 36.4% (4/11). There were no significant intergroup differences in anastomotic leakage and pelvic infection (all P > .05). Conclusion: Positive bacterial culture of fluid during Lap-taTME indicates an increased risk of pelvic infection after operation. Lap-taTME is more prone to intraoperative contamination than Lap-TME but does not significantly increase the risk of postoperative pelvic infection.

Despite its recognized importance, there is currently no reliable tool for surgical quality assurance (SQA) of gastrectomy in surgical oncology. The aim of this study was to develop an SQA tool for gastrectomy and to apply this tool within the ADDICT Trial in order to assess the extent and completeness of lymphadenectomy.

The operative steps for D1+ and D2 gastrectomy have been previously described in the literature and ADDICT trial manual. Two researchers also performed fieldwork in the UK and Japan to document key operative steps through photographs and semi-structured interviews with expert surgeons. This provided the steps that were used as the framework for the SQA tool. Sixty-two photographic cases from the ADDICT Trial were rated by three independent surgeons. Generalizability (G) theory determined inter-rater reliability. D-studies examined the effect of varying the number of assessors and photographic series they rated. Chi-square assessed intra-rater reliability, comparing how the individual assessor's responses corresponded to their global rating for extent of lymphadenectomy.

The tool comprised 20 items, including 19 anatomical landmarks and a global rating score. Overall reliability had G-coefficient of 0.557. Internal consistency was measured with a Cronbach's alpha score of 0.869 and Chi-square confirmed intra-rater reliability for each assessor as < 0.05.

A photographic surgical quality assurance tool is presented for gastrectomy. Using this tool, the assessor can reliably determine not only the quality but also the extent of the lymphadenectomy performed based on remaining anatomy rather than the excised specimen.

The oncological safety of transanal total mesorectal excision (taTME) remains uncertain, and its special surgical approach may contribute to tumor cell dissemination. Thus, we conducted a study to investigate the impact of surgical approach on circulating tumor cell (CTC) counts and phenotypes in rectal cancer.

This is a prospective randomized controlled study (ClinicalTrials: NCT05109130). The patients were randomized to either the taTME (n = 49) or laparoscopic TME (laTME) (n = 48) groups. Blood samples were collected from the central vein to measure CTC counts and phenotypes at three time points: preoperative (t1), immediately post-tumor removal (t2), and one week post-surgery (t3). The effect of surgical procedure on CTCs at each time point was analyzed, with the primary endpoint being the change in CTC counts from t1 to t3 for each surgical approach. This study adheres to Consolidated Standards of Reporting Trials Guidelines.

The baseline clinicopathologic characteristics of the laTME and taTME groups were balanced. The change in CTC count from t1 to t3 was 1.81 ± 5.66 in the laTME group and 2.18 ± 5.53 in the taTME group. The taTME surgery was non-inferior to laTME in terms of changing CTC counts (mean difference [MD]: -0.371; 95% confidence interval [CI]: -2.626 to 1.883, upper-sided 95% CI of 1.883 < 2, non-inferiority boundary value). Compared with that at t1, the CTC count at t2 did not change significantly. However, higher CTC counts were detected at t3 than at t2 in the taTME (P = 0.032) and laTME (P = 0.003) groups. From t1 to t3, CTC counts significantly increased in both the taTME (P = 0.008) and laTME (P = 0.031) groups. There were no significant differences in CTC phenotype changes between the two groups from t1 to t3.

Compared with laTME, taTME did not affect CTC counts and phenotypes. Our findings indicate that taTME is not inferior to laTME in terms of CTC changes from an oncological perspective.

Literature on nationwide long-term permanent stoma rates after rectal cancer resection in the minimally invasive era is scarce. The aim of this population-based study was to provide more insight into the permanent stoma rate with interhospital variability (IHV) depending on surgical technique, with pelvic sepsis, unplanned reinterventions and readmissions as secondary outcomes.

Patients who underwent open or minimally invasive resection of rectal cancer (lower border below the sigmoid take-off) in 67 Dutch centres in 2016 were included in this cross-sectional cohort study.

Among 2530 patients, 1470 underwent a restorative resection (58%), 356 a Hartmann's procedure (14%, IHV 0%-42%) and 704 an abdominoperineal resection (28%, IHV 3%-60%). Median follow-up was 51 months. The overall permanent stoma rate at last follow-up was 50% (IHV 13%-79%) and the unintentional permanent stoma rate, permanent stoma after a restorative procedure or an unplanned Hartmann's procedure, was 11% (IHV 0%-29%). A total of 2165 patients (86%) underwent a minimally invasive resection: 1760 conventional (81%), 170 transanal (8%) and 235 robot-assisted (11%). An anastomosis was created in 59%, 80% and 66%, with corresponding unintentional permanent stoma rates of 12%, 24% and 14% (p = 0.001), respectively. When corrected for age, American Society of Anesthesiologists classification, cTNM, distance to the anorectal junction and neoadjuvant (chemo)radiotherapy, the minimally invasive technique was not associated with an unintended permanent stoma (p = 0.071) after a restorative procedure.

A remarkable IHV in the permanent stoma rate after rectal cancer resection was found. No beneficial influence of transanal or robot-assisted laparoscopy on the unintentional permanent stoma rate was found, although this might be caused by the surgical learning curve. A reduction in IHV and improving preoperative counselling for decision-making for restorative procedures are required.

Total mesorectal excision (TME) is the standard surgery for low/mid locally advanced rectal cancer. The aim of this study was to compare three minimally invasive surgical approaches for TME with primary anastomosis (laparoscopic TME, robotic TME, and transanal TME).

Records of patients undergoing laparoscopic TME, robotic TME, or transanal TME between 2013 and 2022 according to standardized techniques in expert centres contributing to the European MRI and Rectal Cancer Surgery III (EuMaRCS-III) database were analysed. Propensity score matching was applied to compare the three groups with respect to the complication rate (primary outcome), conversion rate, postoperative recovery, and survival.

A total of 468 patients (mean(s.d.) age of 64.1(11) years) were included; 190 (40.6%) patients underwent laparoscopic TME, 141 (30.1%) patients underwent robotic TME, and 137 (29.3%) patients underwent transanal TME. Comparative analyses after propensity score matching demonstrated a higher rate of postoperative complications for laparoscopic TME compared with both robotic TME (OR 1.80, 95% c.i. 1.11-2.91) and transanal TME (OR 2.87, 95% c.i. 1.72-4.80). Robotic TME was associated with a lower rate of grade A anastomotic leakage (2%) compared with both laparoscopic TME (8.8%) and transanal TME (8.1%) (P = 0.031). Robotic TME (1.4%) and transanal TME (0.7%) were both associated with a lower conversion rate to open surgery compared with laparoscopic TME (8.8%) (P < 0.001). Time to flatus and duration of hospital stay were shorter for patients treated with transanal TME (P = 0.003 and 0.001 respectively). There were no differences in operating time, intraoperative complications, blood loss, mortality, readmission, R0 resection, or survival.

In this multicentre, retrospective, propensity score-matched, cohort study of patients with locally advanced rectal cancer, newer minimally invasive approaches (robotic TME and transanal TME) demonstrated improved outcomes compared with laparoscopic TME.

Transanal total mesorectal excision is a novel surgical treatment for mid to low rectal cancers. Norwegian population data have raised concerns about local recurrence in patients treated with transanal total mesorectal excision.

This study aimed to analyze local recurrence and disease-free survival in patients treated by transanal total mesorectal excision for rectal cancer at a high-volume tertiary center.

This retrospective study used a prospectively maintained institutional transanal total mesorectal excision database. Patient demographics, treatment, and outcomes data were analyzed. Local recurrence, disease-free survival, and overall survival were analyzed using Kaplan-Meier analysis.

The study was conducted at a single academic institution in Vancouver, Canada.

All patients treated by transanal total mesorectal excision for rectal adenocarcinoma between 2014 and 2022 were included.

The primary outcome was local recurrence-free survival.

Between 2014 and 2022, 306 patients were treated by transanal total mesorectal excision at St. Paul's Hospital. Of these, 279 patients met the inclusion criteria. The mean age was 62 years (SD ± 12.3), and 66.7% of patients were men. Restorative resection was achieved in 97.5% of patients, with a conversion rate from laparoscopic to open surgery of 6.8%. The composite optimal pathological outcome was 93.9%. The median follow-up was 26 months (interquartile range, 12-47), and 82.8% of patients achieved reestablishment of GI continuity to date. The overall local recurrence rate was 4.7% (n = 13). The estimated 2-year local recurrence-free survival rate was 95.0% (95% CI, 92-98) and the estimated 5-year local recurrence-free survival rate was 94.5% (95% CI, 91-98).

Limitations include the retrospective nature of the study and the generalizability of a Canadian population.

Recent European data have challenged the presumed oncologic safety of transanal total mesorectal excision. Although the learning curve for this procedure is challenging and poor outcomes are associated with low volume, this high-volume single-center study confirms acceptable oncologic outcomes consistent with the current standard. See Video Abstract .

ANTECEDENTES:La excisión total del mesorecto por vía transanal es un tratamiento quirúrgico novedoso para los cánceres de recto medio a bajo. Estudios sobre la población noruega han generado preocupación debido a la recidiva local en pacientes tratados con excisión total del mesorecto por vía transanal.OBJETIVO:Nuestra finalidad fué de analizar la recidiva local y la sobrevida libre de enfermedad en pacientes tratados mediante la excisión total del mesorecto por vía transanal, debido a un cáncer de recto en un centro terciario de alto volúmen.DISEÑO:El presente estudio retrospectivo, utiliza una base de datos institucional sobre la excisión total del mesorecto por vía transanal mantenida prospectivamente. Se analizaron los datos demográficos, de tratamiento y los resultados de los pacientes sometidos a la técnica mencionada. La recidiva local, la sobrevida libre de enfermedad y la sobrevida global se analizaron mediante el modelo de Kaplan-Meier.AJUSTES:El estudio se llevó a cabo en una sola institución académica en Vancouver, Canadá.PARTICIPANTES:Se incluyeron todos los pacientes tratados mediante excisión total del mesorecto por vía transanal causado por adenocarcinomas de recto entre 2014 y 2022.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la sobrevida libre de recidiva local.RESULTADOS:Entre 2014 y 2022, 306 pacientes fueron tratados mediante la excisión total del mesorecto por vía transanal en el Hospital St. Paul. De estos, 279 pacientes cumplieron los criterios de inclusión. La edad media fue de 62 años (DE ± 12,3) y el 66,7% de los pacientes eran varones. La resección restauradora se logró en el 97,5% de los pacientes con una tasa de conversión de cirugía laparoscópica en laparotomía del 6,8%. El resultado patológico óptimo combinado fué del 93,9%. La mediana de seguimiento fue de 26 meses (rango intercuartil 12-47) y el 82,8% logró el restablecimiento de la continuidad gastrointestinal hasta la fecha. La tasa global de recidiva local fué del 4,7% (n = 13). La sobrevida libre de recidiva local estimada a los 2 años fué del 95,0% (IC del 95%: 92-98) y del 94,5% a los 5 años (IC del 95%: 91-98).LIMITACIONES:Las limitaciones incluyen la naturaleza retrospectiva del estudio y la generalización de una población canadiense.CONCLUSIONES:Datos europeos recientes han cuestionado la supuesta seguridad oncológica de la excisión total del mesorecto por vía transanal. Si bien la curva de aprendizaje de este procedimiento es muy desafiante y los malos resultados se asocian con un volumen bajo, el presente estudio, unicéntrico de gran volumen confirma los resultados oncológicos aceptables consistentes con el estándar actual. (Traducción-Dr. Xavier Delgadillo ).

To investigate the oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer and risk factors for local recurrence (LR).

A high LR rate with a multifocal pattern early after TaTME has been reported in Norway and the Netherlands, causing controversy over the oncological safety of this technique.

Twenty-six member institutions of the Japan Society of Laparoscopic Colorectal Surgery participated in this retrospective cohort study. A total of 706 patients with primary rectal cancer who underwent TaTME between January 2012 and December 2019 were included for analysis. The primary endpoint was the cumulative 3-year LR rate.

A total of 253 patients had clinical stage III disease (35.8%) and 91 (12.9%) had stage IV. Intersphincteric resection was performed in 318 patients (45.0%) and abdominoperineal resection in 193 (27.3%). There was 1 urethral injury (0.1%). A positive resection margin (R1) was seen in 42 patients (5.9%). Median follow-up was 3.42 years, and the 2- and 3-year cumulative LR rates were 4.95% (95% confidence interval: 3.50-6.75) and 6.82% (95% confidence interval: 5.08-8.89), respectively. A multifocal pattern was observed in 14 (25%) of 56 patients with LR. Tumor height from the anal verge, pathological T4 disease, pathological stage III/IV, positive perineural invasion, and R1 resection were significant risk factors for LR in multivariable analysis.

In this selected cohort in which intersphincteric resection or abdominoperineal resection was performed in more than half of cases, oncological outcomes were acceptable during a median follow-up of more than 3 years.

Transanal total mesorectal excision (taTME) was developed to provide better vision during resection of the mesorectum. Conflicting results have shown an increase in local recurrence and shorter survival after taTME. This study compared the outcomes of taTME and abdominal (open, laparoscopic, robotic) total mesorectal excision (abTME).

Patients who underwent taTME or abTME for stages I-III rectal cancer and who received an anastomosis were included. A retrospective analysis of a prospectively conducted database was performed. The primary endpoints were overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Risk factors were adjusted by propensity score matching (PSM). The secondary endpoints were local recurrence rates and combined poor pathological outcomes.

From 2012 to 2020, a total of 189 patients underwent taTME, and 119 underwent abTME; patients were followed up for a mean of 54.7 (SD 24.2) and 78.4 (SD 34.8) months, respectively (p < 0.001). The 5-year survival rates after taTME and abTME were not significantly different after PSM: OS: 78.2% vs. 88.6% (p = 0.073), CSS: 87.4% vs. 92.1% (p = 0.359), and DFS: 69.3% vs. 80.9% (p = 0.104), respectively. No difference in the local recurrence rate was observed (taTME, n = 10 (5.3%); abTME, n = 10 (8.4%); p = 0.280). Combined poor pathological outcomes were more frequent after abTME (n = 36, 34.3%) than after taTME (n = 35, 19.6%) (p = 0.006); this difference was nonsignificant according to multivariate analysis (p = 0.404).

taTME seems to be a good treatment option for patients with rectal cancer and is unlikely to significantly affect local recurrence or survival. However, further investigations concerning the latter are warranted.

ClinicalTrials.gov (NCT0496910).

Laparoscopic total mesorectal excision (LaTME) is standard surgical methods for rectal cancer, and LaTME operation is a challenging procedure. This study is intended to use machine learning to develop and validate prediction models for surgical difficulty of LaTME in patients with rectal cancer and compare these models' performance.

We retrospectively collected the preoperative clinical and MRI pelvimetry parameter of rectal cancer patients who underwent laparoscopic total mesorectal resection from 2017 to 2022. The difficulty of LaTME was defined according to the scoring criteria reported by Escal. Patients were randomly divided into training group (80%) and test group (20%). We selected independent influencing features using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression method. Adopt synthetic minority oversampling technique (SMOTE) to alleviate the class imbalance problem. Six machine learning model were developed: light gradient boosting machine (LGBM); categorical boosting (CatBoost); extreme gradient boost (XGBoost), logistic regression (LR); random forests (RF); multilayer perceptron (MLP). The area under receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity and F1 score were used to evaluate the performance of the model. The Shapley Additive Explanations (SHAP) analysis provided interpretation for the best machine learning model. Further decision curve analysis (DCA) was used to evaluate the clinical manifestations of the model.

A total of 626 patients were included. LASSO regression analysis shows that tumor height, prognostic nutrition index (PNI), pelvic inlet, pelvic outlet, sacrococcygeal distance, mesorectal fat area and angle 5 (the angle between the apex of the sacral angle and the lower edge of the pubic bone) are the predictor variables of the machine learning model. In addition, the correlation heatmap shows that there is no significant correlation between these seven variables. When predicting the difficulty of LaTME surgery, the XGBoost model performed best among the six machine learning models (AUROC=0.855). Based on the decision curve analysis (DCA) results, the XGBoost model is also superior, and feature importance analysis shows that tumor height is the most important variable among the seven factors.

This study developed an XGBoost model to predict the difficulty of LaTME surgery. This model can help clinicians quickly and accurately predict the difficulty of surgery and adopt individualized surgical methods.

Total mesorectal excision (TME) with delayed coloanal anastomosis (DCAA) is surgical option for low rectal cancer, replacing conventional immediate coloanal anastomosis (ICAA) with bowel diversion. This study aimed to assess the outcomes of transanal TME (TaTME) with DCAA versus laparoscopic TME (LTME) with ICAA versus robotic TME (RTME) with ICAA.

This was a retrospective propensity score-matched analysis of patients who underwent elective TaTME-DCAA between November 2021 and June 2022. Patients were propensity-score matched in a ratio of 1:3 to patients who underwent LTME-ICAA and RTME-ICAA from January 2019 to December 2020. Outcome measures were histopathologic results, postoperative morbidity, function, and inpatient costs.

Twelve patients in the TaTME-DCAA group were compared with 36 patients in the LTME-ICAA and RTME-ICAA groups each after propensity score matching. Histopathologic results and postoperative morbidity rates were statistically similar. Overall stoma-related complication rates in the ICAA groups were 11%. Median total length of hospital stays for TME plus stoma reversal surgery was similar across all techniques (10 vs. 10 vs. 9 days; P =0.532). Despite a significantly shorter duration of follow-up, bowel function after TaTME-DCAA was comparable to that of LTME-ICAA and RTME-ICAA. Overall median inpatient costs of TaTME-DCAA were comparable to LTME-ICAA and significantly cheaper than RTME-ICAA ($31,087 vs. $29,927 vs. $36,750; P =0.002).

TaTME with DCAA is a feasible and safe technique compared with other minimally invasive methods of TME, while avoiding bowel diversion and stoma-related complications, as well as comparing favorably in terms of overall hospitalization costs.

Minimally invasive surgery (MIS) is currently the standard treatment for rectal cancer. However, its limitations include complications and incomplete total mesorectal resection (TME) due to anatomical features and technical difficulties. Transanal TME (TaTME) has been practiced since 2010 to improve this, but there is a risk of local recurrence and intra-abdominal contamination. We aimed to analyze samples obtained through lavage to compare laparoscopic TME (LapTME) and TaTME.

From June 2020 to January 2021, 20 patients with rectal cancer undergoing MIS were consecutively and prospectively recruited. Samples were collected at the start of surgery, immediately after TME, and after irrigation. The samples were analyzed for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) through a quantitative real-time polymerase chain reaction. The primary outcome was to compare the detected amounts of CEA and CK20 immediately after TME between the surgical methods.

Among the 20 patients, 13 underwent LapTME and 7 underwent TaTME. Tumor location was lower in TaTME (7.3 cm vs. 4.6 cm, P=0.012), and negative mesorectal fascia (MRF) was more in LapTME (76.9% vs. 28.6%, P=0.044). CEA and CK20 levels were high in 3 patients (42.9%) only in TaTME. There was 1 case of T4 with incomplete purse-string suture and 1 case of positive MRF with dissection failure. All patients were followed up for an average of 32.5 months without local recurrence.

CEA and CK20 levels were high only in TaTME and were related to tumor factors or intraoperative events. However, whether the detection amount is clinically related to local recurrence remains unclear.

Transanal TME (taTME) combines abdominal and transanal dissection to facilitate sphincter preservation in patients with low rectal tumors. Few phase II/III trials report long-term oncologic and functional results. We report early results from a North American prospective multicenter phase II trial of taTME (NCT03144765).

100 patients with stage I-III rectal adenocarcinoma located ≤ 10 cm from the anal verge (AV) were enrolled across 11 centers. Primary and secondary endpoints were TME quality, pathologic outcomes, 30-day and 90-day outcomes, and stoma closure rate. Univariable regression analysis was performed to assess risk factors for incomplete TME and anastomotic complications.

Between September 2017 and April 2022, 70 males and 30 females with median age of 58 (IQR 49-62) years and BMI 27.8 (IQR 23.9-31.8) kg/m2 underwent 2-team taTME for tumors located a median 5.8 (IQR 4.5-7.0) cm from the AV. Neoadjuvant radiotherapy was completed in 69%. Intersphincteric resection was performed in 36% and all patients were diverted. Intraoperative complications occurred in 8% including 3 organ injuries, 2 abdominal and 1 transanal conversion. The 30-day and 90-day morbidity rates were 49% (Clavien-Dindo (CD) ≥ 3 in 28.6%) and 56% (CD ≥ 3 in 30.4% including 1 mortality), respectively. Anastomotic complications were reported in 18% including 10% diagnosed within 30 days. Higher anastomotic risk was noted among males (p = 0.05). At a median follow-up of 5 (IQR 3.1-7.4) months, 98% of stomas were closed. TME grade was complete or near complete in 90%, with positive margins in 2 cases (3%). Risk factors for incomplete TME were ASA ≥ 3 (p = 0.01), increased time between NRT and surgery (p = 0.03), and higher operative blood loss (p = 0.003).

When performed at expert centers, 2-team taTME in patients with low rectal tumors is safe with low conversion rates and high stoma closure rate. Mid-term results will further evaluate oncologic and functional outcomes.

Magnetic resonance (MR) imaging is the modality used for baseline assessment of locally advanced rectal cancer (LARC) and restaging after neoadjuvant treatment. The overall audited quality of MR imaging in large multicentre trials on rectal cancer is so far not routinely reported.

We collected MR images obtained within the Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation (RAPIDO) trial and performed an audit of the technical features of image acquisition. The required MR sequences and slice thickness stated in the RAPIDO protocol were used as a reference.

Out of 920 participants of the RAPIDO study, MR investigations of 668 and 623 patients in the baseline and restaging setting, respectively, were collected. Of these, 304/668 (45.5%) and 328/623 (52.6%) MR images, respectively, fulfilled the technical quality criteria. The main reason for non-compliance was exceeding slice thickness 238/668, 35.6% in the baseline setting and 162/623, 26.0% in the restaging setting. In 166/668, 24.9% and 168/623, 27.0% MR images in the baseline and restaging setting, respectively, one or more of the required pulse sequences were missing.

Altogether, 49.0% of the MR images obtained within the RAPIDO trial fulfilled the image acquisition criteria required in the study protocol. High-quality MR imaging should be expected for the appropriate initial treatment and response evaluation of patients with LARC, and efforts should be made to maximise the quality of imaging in clinical trials and in clinical practice.

This audit highlights the importance of adherence to MR image acquisition criteria for rectal cancer, both in multicentre trials and in daily clinical practice. High-resolution images allow correct staging, treatment stratification and evaluation of response to neoadjuvant treatment.

- Complying to MR acquisition guidelines in multicentre trials is challenging. - Neglection on MR acquisition criteria leads to poor staging and treatment. - MR acquisition guidelines should be followed in trials and clinical practice. - Researchers should consider mandatory audits prior to study initiation.

Laparoscopic surgery is widely used for rectal cancer; however, this technique is challenging due to tapering of the mesorectum in the pelvis, and the forward angle of the distal rectum, which renders this part of the rectum less accessible from the abdominal cavity. Hence, concerns regarding its safety and curability have been raised, particularly for inadequate distal and circumferential resection margins. Recently, transanal total mesorectal excision (TaTME), which involves endoscopic total mesorectal excision (TME) retrogradely from the anal side, has attracted attention worldwide as a solution to these problems. TaTME is superior to the conventional laparoscopic approach for rectal cancer in terms of both oncological and functional preservations. However, a shallow learning curve caused by the unfamiliar anatomical view from the anal side can pose challenges. Therefore, an efficient educational system needs to be established. Randomized controlled trials comparing conventional laparoscopic TME with TaTME are ongoing to demonstrate the usefulness of TaTME. This article reviews changes in the surgical treatment of rectal cancer, with a focus on TaTME, and describes the indications, surgical techniques, and training curricula for TaTME.

The objective of this study was to evaluate treatment outcomes in patients who underwent the TaTME procedure for cancer of the middle and low rectum in an expert center. Prospective analysis of the outcomes of all consecutive patients treated using the TaTME technique for cancer of the middle and distal rectum at the our medical center between March 1, 2015, and March 31, 2022. A total of 128 patients (34 women, 94 men; mean age 66.01 [38-85] years) with cancer of the middle and distal rectum qualified for TaTME. TaTME procedures were performed in 127/128 (99.22%) patients. Complications of surgery were observed in 22/127 (17.32%) patients. Negative proximal and distal margins were confirmed in all 127 patients. Complete (R0) resection of the mesorectum was confirmed in 125/127 (98.43%) and nearly complete (R1) resection was confirmed in 2/127 (1.57%) patients. The average follow-up period was 795 days (296-1522) days. Local recurrence was detected during the follow-up period in 2/127 (1.57%) patients. This study showed that the TaTME procedure is an effective and safe method for the minimally invasive treatment of middle and low rectal cancers, particularly within an expert center setting.

Colorectal surgery has witnessed a transformative shift with the advent of minimally invasive techniques, offering patients reduced postoperative discomfort, shorter hospital stays, and accelerated recovery compared to conventional open surgery. This comprehensive review aims to assess the current state of minimally invasive approaches in colorectal surgery, encompassing various techniques such as single-incision laparoscopic surgery, robot-assisted surgery, and conventional laparoscopic surgery. The article meticulously explores the benefits and drawbacks of each technique, delves into the established criteria for their application, delineates cautious circumstances, and analyzes the outcomes of minimally invasive colorectal surgery. Additionally, the integration of virtual reality and augmented reality for surgical planning and training is discussed, shedding light on the future trajectory of this field. Surgeons and researchers striving to enhance patient care and surgical outcomes in colorectal surgery will find this review article an invaluable resource, presenting crucial components of minimally invasive colorectal surgery and paving the way for continued advancements in the field.

Transanal total mesorectal excision (TaTME) has been proposed to overcome surgical difficulties encountered during rectal resection, especially for patients having high body mass index or low rectal cancer. The aim of this study was to evaluate oncologic outcomes following TaTME.

This retrospective study included all consecutive patients with rectal cancer who had a TaTME from 2013 to 2019. The main outcome was the incidence of locoregional recurrence by the end of the follow-up period.

Among a total of 81 patients, 96.3% were male, and their mean age was 63±9 years. The mean body mass index was 30.3±5.7 kg/m2, and the median distance from tumor to anal verge was 5.0 cm (interquartile range [IQR], 4.0-6.0 cm). Most patients had a low anterior resection performed (n=80, 98.8%) with a diverting ileostomy (n=64, 79.0%). Distal and circumferential resection margins were positive in 2.5% and 6.2% of patients, respectively. Total mesorectal excision was complete or near complete in 95.1% of patients. A successful resection was achieved in 72 patients (88.9%). After a median follow-up of 27.5 months (IQR, 16.7-48.1 months), 4 patients (4.9%) experienced locoregional recurrence. Anastomotic leaks were observed in 21 patients (25.9%). At the end of the follow-up, 69 patients (85.2%) were stoma-free.

TaTME was associated with acceptable oncological outcomes, including low locoregional recurrence rates in selected patients with low rectal cancer. Although associated with a high incidence of postoperative morbidities, the use of TaTME enabled a high rate of successful sphincter-saving procedures in selected patients who posed a technical challenge.

To evaluate the efficacy and safety of simple TaTNE in the treatment of low rectal cancer compared with laparoscopic transabdominal TME.

We collected patients with low rectal cancer admitted to our hospital between January 2019 and November 2021 who received simple TaTME or laparoscopic transabdominal TME. The main outcome was the integrity of the TME specimen. Secondary outcomes were the number of lymph nodes dissected, intraoperative blood loss, operative time, surgical conversion rate, Specimen resection length, circumferential margin (CRM), and distal resection margin (DRM), complication rate. In addition, the Wexner score and LARS score of fecal incontinence were performed in postoperative follow-up.

Pathological tissues were successfully resected in all patients. all circumferential margins of the specimen were negative. Specimen resection length was not statistically significant (9.94 ± 2.85 vs. 8.90 ± 2.49, P > 0.05). The incidence of postoperative complications in group A (n = 0) was significantly lower than that in group B (n = 3) (P > 0.05). There was no significant difference in operation time between group A and group B (296 ± 60.36 vs. 305 ± 58.28, P > 0.05). Among the patients with follow-up time less than 1 year, there was no significant difference in Wexner score and LARS score between group A and group B (P > 0.05). However, in patients who were followed up for more than 1 year, the Wexner score in group A (9.25 ± 2.73) was significantly lower than that in group B (17.36 ± 10.95) and was statistically significant (P < 0.05).

For radical resection of low rectal cancer, Simple TaTME resection may be as safe and effective as laparoscopic transabdominal TME, and the long-term prognosis may be better.

Minimally invasive total mesorectal excision (MiTME) and transanal total mesorectal excision (TaTME) are popular trends in mid and low rectal cancer. However, there is currently no systematic comparison between MiTME and TaTME of mid and low-rectal cancer. Therefore, we systematically study the perioperative and pathological outcomes of MiTME and TaTME in mid and low rectal cancer.

We have searched the Embase, Cochrane Library, PubMed, Medline, and Web of Science for articles on MiTME (robotic or laparoscopic total mesorectal excision) and TaTME (transanal total mesorectal excision). We calculated pooled standard mean difference (SMD), relative risk (RR), and 95% confidence intervals (CIs). The protocol for this review has been registered on PROSPERO (CRD42022374141).

There are 11010 patients including 39 articles. Compared with TaTME, patients who underwent MiTME had no statistical difference in operation time (SMD -0.14; CI -0.31 to 0.33; I²⁼84.7%, P=0.116), estimated blood loss (SMD 0.05; CI -0.05 to 0.14; I²⁼48%, P=0.338), postoperative hospital stay (RR 0.08; CI -0.07 to 0.22; I²⁼0%, P=0.308), over complications (RR 0.98; CI 0.88 to 1.08; I²⁼25.4%, P=0.644), intraoperative complications (RR 0.94; CI 0.69 to 1.29; I²⁼31.1%, P=0.712), postoperative complications (RR 0.98; CI 0.87 to 1.11; I²⁼16.1%, P=0.789), anastomotic stenosis (RR 0.85; CI 0.73 to 0.98; I²⁼7.4%, P=0.564), wound infection (RR 1.08; CI 0.65 to 1.81; I²⁼1.9%, P=0.755), circumferential resection margin (RR 1.10; CI 0.91 to 1.34; I²⁼0%, P=0.322), distal resection margin (RR 1.49; CI 0.73 to 3.05; I²⁼0%, P=0.272), major low anterior resection syndrome (RR 0.93; CI 0.79 to 1.10; I²⁼0%, P=0.386), lymph node yield (SMD 0.06; CI -0.04 to 0.17; I²⁼39.6%, P=0.249), 2-year DFS rate (RR 0.99; CI 0.88 to 1.11; I²⁼0%, P = 0.816), 2-year OS rate (RR 1.00; CI 0.90 to 1.11; I²⁼0%, P = 0.969), distant metastasis rate (RR 0.47; CI 0.17 to 1.29; I²⁼0%, P = 0.143), and local recurrence rate (RR 1.49; CI 0.75 to 2.97; I²⁼0%, P = 0.250). However, patients who underwent MiTME had fewer anastomotic leak rates (SMD -0.38; CI -0.59 to -0.17; I²⁼19.0%, P<0.0001).

This study comprehensively and systematically evaluated the safety and efficacy of MiTME and TaTME in the treatment of mid to low-rectal cancer through meta-analysis. There is no difference between the two except for patients with MiTME who have a lower anastomotic leakage rate, which provides some evidence-based reference for clinical practice. Of course, in the future, more scientific and rigorous conclusions need to be drawn from multi-center RCT research.

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022374141.

Quality of surgery has substantial impact on both short- and long-term clinical outcomes. This stresses the need for objective surgical quality assessment (SQA) for education, clinical practice and research purposes. The aim of this systematic review was to provide a comprehensive overview of all video-based objective SQA tools in laparoscopic procedures and their validity to objectively assess surgical performance.

PubMed, Embase.com and Web of Science were systematically searched by two reviewers to identify all studies focusing on video-based SQA tools of technical skills in laparoscopic surgery performed in a clinical setting. Evidence on validity was evaluated using a modified validation scoring system.

Fifty-five studies with a total of 41 video-based SQA tools were identified. These tools were used in 9 different fields of laparoscopic surgery and were divided into 4 categories: the global assessment scale (GAS), the error-based assessment scale (EBAS), the procedure-specific assessment tool (PSAT) and artificial intelligence (AI). The number of studies focusing on these four categories were 21, 6, 31 and 3, respectively. Twelve studies validated the SQA tool with clinical outcomes. In 11 of those studies, a positive association between surgical quality and clinical outcomes was found.

This systematic review included a total of 41 unique video-based SQA tools to assess surgical technical skills in various domains of laparoscopic surgery. This study suggests that validated SQA tools enable objective assessment of surgical performance with relevance for clinical outcomes, which can be used for training, research and quality improvement programs.

Total mesorectal excision (TME) for rectal cancer can be achieved using open (OpTME), laparoscopic (LapTME), robotic (RoTME), or transanal techniques (TaTME). However, the optimal approach for access remains controversial. The aim of this network meta-analysis was to assess operative and oncological outcomes of all four surgical techniques.

Ovid MEDLINE, EMBASE, and PubMed databases were searched systematically from inception to September 2020, for randomised controlled trials (RCTs) comparing any two TME surgical techniques. A network meta-analysis using a Bayesian random-effects framework and mixed treatment comparison was performed. Primary outcomes were the rate of clear circumferential resection margin (CRM), defined as > 1 mm from the closest tumour to the cut edge of the tissue, and completeness of mesorectal excision. Secondary outcomes included radial and distal resection margin distance, postoperative complications, locoregional recurrence, disease-free survival, and overall survival. Surface under cumulative ranking (SUCRA) was used to rank the relative effectiveness of each intervention for each outcome. The higher the SUCRA value, the higher the likelihood that the intervention is in the top rank or one of the top ranks.

Thirty-two RCTs with a total of 6151 patients were included. Compared with OpTME, there was no difference in the rates of clear CRM: LapTME RR = 0.99 (95% (Credible interval) CrI 0.97-1.0); RoTME RR = 1.0 (95% CrI 0.96-1.1); TaTME RR = 1.0 (95% CrI 0.96-1.1). There was no difference in the rates of complete mesorectal excision: LapTME RR = 0.98 (95% CrI 0.98-1.1); RoTME RR = 1.1 (95% CrI 0.98-1.4); TaTME RR = 1.0 (95% CrI 0.91-1.2). RoTME was associated with improved distal resection margin distance compared to other techniques (SUCRA 99%). LapTME had a higher rate of conversion to open surgery when compared with RoTME: RoTME RR = 0.23 (95% CrI 0.034-0.70). Length of stay was shortest in RoTME compared to other surgical approaches: OpTME mean difference in days (MD) 3.3 (95% CrI 0.12-6.0); LapTME MD 1.7 (95% CrI - 1.1-4.4); TaTME MD 1.3 (95% CrI - 5.2-7.4). There were no differences in 5-year overall survival (LapTME HR 1.1, 95% CrI 0.74, 1.4; TaTME HR 1.7, 95% CrI 0.79, 3.4), disease-free survival rates (LapTME HR 1.1, 95% CrI 0.76, 1.4; TaTME HR 1.1, 95% CrI 0.52, 2.4), or anastomotic leakage (LapTME RR = 0.92 (95% CrI 0.63, 1.1); RoTME RR = 1.0 (95% CrI 0.48, 1.8); TaTME RR = 0.53 (95% CrI 0.19, 1.2). The overall quality of evidence as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) assessments across all outcomes including primary and secondary outcomes was deemed low.

In selected patients eligible for a RCT, RoTME achieved improved distal resection margin distance and a shorter length of hospital stay. No other differences were observed in oncological or recovery parameters between (OpTME), laparoscopic (LapTME), robotic (RoTME), or trans-anal TME (TaTME). However, the overall quality of evidence across all outcomes was deemed low.

There is no intraluminal guidance to ensure complete inclusion of the mesorectum in transanal total mesorectal excision (taTME). This study aimed to assess the distance difference between the anterior and posterior mesorectal terminal ends and the anal verge as a potential risk for residual mesorectum after resection.

Forty-four surgical specimens of extra-levator abdominoperineal excision (ELAPE) and 28 mid-sagittal cadaveric specimens were included to this study. The distance between the mesorectum terminal end (T) and the endoluminal landmarks (dentate line (D)/anal verge (A)) was measured and compared between men and women. Furthermore, 66 MRI images from The Cancer Imaging Archive (TCIA) were used to validate the same concept in a non-Asian population.

The mesorectal terminal end was found to be aligned along with the levator hiatus. From the midsagittal view, the ELAPE specimens showed that the distance between T and A anteriorly was significantly longer than the same distance posteriorly (34.74±7.79mm vs 23.74±4.24mm, P<0.001). Similarly, the distance measured in the cadaveric specimens was significantly longer anteriorly than posteriorly (P<0.001). The validation cohort of non-Asian MRI image has confirmed the same (56.68±14.17mm vs. 38.18 ±10.42mm, P<0.001(. There was no significant difference between men and women.

Because of the remarkable distance difference between the anterior and posterior mesorectal terminal ends away from the anal verge, the taTME proctectomy level may not meet the required mesorectal end. Thus, if TME is planned, aligning the proctectomy level around the levator hiatus would be the best place that can ensure complete TME.

Laparoscopic surgery for low rectal cancer is often challenging. Transanal total mesorectal excision (TaTME) and robotic surgery have been introduced to overcome the technical difficulties in laparoscopic surgery and achieve more favorable outcomes. Hybrid robotic surgery, which combines TaTME with the abdominal robotic approach, incorporates the advantages of each of these surgical techniques and might achieve less invasive and safer surgery. This study evaluated the safety and feasibility of hybrid robotic surgery with TaTME (hybrid TaTME).

We retrospectively reviewed 162 TaTME cases performed at our department from September 2016 to May 2022. Among them, 92 cases of conventional TaTME and 30 of hybrid TaTME were eligible. We used propensity score matching analysis (PSM) to adjust for patients' characteristics and compared the short-term outcomes of the two treatment groups.