Essential knowledge and technical tips for total mesorectal excision and related procedures for rectal cancer.

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.

Beyond total mesorectal excision: The emerging role of minimally invasive surgery for locally advanced rectal cancer.

Multivisceral resection and/or pelvic exenteration represents the only potential curative treatment for locally advanced rectal cancer (LARC); however, it poses significant technical challenges, which account for the high risk of morbidity and mortality associated with the procedure. As complete histopathologic resection is the most important determinant of patient outcomes, LARC often requires an extended resection beyond the total mesorectal excision plane to obtain clear resection margins. In an era when laparoscopic surgery and robot-assisted surgery are becoming commonplace, the optimal approach to extensive pelvic interventions remains controversial. However, acceptance of the suitability of minimally invasive surgery is slowly gaining traction. Nonetheless, there is still a lack of evidence in the literature about minimally invasive approaches in multiple and extensive surgical resections, highlighting the need for research studies to explore, validate, and develop this issue. This editorial aims to provide a critical overview of the currently available applications and challenges of minimally invasive abdominopelvic surgery for LARC. Furthermore, we discuss recent developments in the field of robotic surgery for LARC, with a specific focus on new innovations and emerging frontiers.

Transanal total mesorectal excision: short- and long-term results of four certified colorectal cancer centers in Germany.

BACKGROUND: Transanal total mesorectal excision (TaTME), a novel approach for treating low rectal cancer, holds promise. However, concerns exist in certain countries about their oncologic safety due to less-than-optimal outcomes on global studies. This research seeks to evaluate the long-term oncologic outcomes focusing on local recurrence rate and overall survival after TaTME surgery in Germany. PATIENTS AND METHODS: This study analyzed data from patients who underwent elective TaTME surgery between 2014 and 2021 in four certified colorectal cancer centers in Germany. Primary endpoints were 3-year local recurrence rate and local recurrence-free survival (LRFS). Secondary outcomes encompassed overall survival (OS), operative time, completeness of local tumor resection, lymph node resection, and postoperative complications. RESULTS: A total of 378 patients were analyzed (mean age 61.6 years; 272 males, 72%). After a median follow-up period of 2.5 years, 326 patients with UICC-stages I-III and tumor operability included in survival analyses. Local recurrence was observed in 8 individuals, leading to a 3-year cumulative local recurrence rate of 2.2% and a 3-year LRFS rate of 88.1%. The 3-year OS rate stood at 88.9%. Within 30 days after surgery, anastomotic leakage occurred in 19 cases (5%), whereas a presacral abscess was present in 12 patients (3.2%). CONCLUSION: TaTME proves effective in addressing the anatomical and technical challenges of low rectal surgery and is associated with pleasing short- and long-term results. However, its safe integration into surgical routine necessitates sufficient knowledge and a previously completed training program.

Prediction of postoperative complications following transanal total mesorectal excision in middle and low rectal cancer: development and internal validation of a clinical prediction model.

PURPOSE: The objective of this study is to develop a nomogram for the personalized prediction of postoperative complication risks in patients with middle and low rectal cancer who are undergoing transanal total mesorectal excision (taTME). This tool aims to assist clinicians in early identification of high-risk patients and in addressing preoperative risk factors to enhance surgical safety. METHODS: In this case-control study, 207 patients diagnosed with middle and low rectal cancer and undergoing taTME between February 2018 and November 2023 at The First Affiliated Hospital of Xiamen University were included. Independent risk factors for postoperative complications were analyzed using the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multifactorial logistic regression models. A predictive nomogram was constructed using R Studio. RESULTS: Among the 207 patients, 57 (27.5%) experienced postoperative complications. The LASSO and multifactorial logistic regression analyses identified operation time (OR = 1.010, P = 0.007), smoking history (OR = 9.693, P < 0.001), anastomotic technique (OR = 0.260, P = 0.004), and ASA score (OR = 9.077, P = 0.051) as significant predictors. These factors were integrated into the nomogram. The model's accuracy was validated through receiver operating characteristic curves, calibration curves, consistency indices, and decision curve analysis. CONCLUSION: The developed nomogram, incorporating operation time, smoking history, anastomotic technique, and ASA score, effectively forecasts postoperative complication risks in taTME procedures. It is a valuable tool for clinicians to identify patients at heightened risk and initiate timely interventions, ultimately improving patient outcomes.

Postoperative urinary retention following transanal versus laparoscopic total mesorectal excision for rectal cancer: A randomized trial report from an experienced center.

Background: Transanal total mesorectal excision has emerged as a potential solution to certain limitations associated with laparoscopic total mesorectal excision in rectal cancer patients. Differences in surgical approaches have raised questions regarding their impact on the risk of postoperative urinary retention, with limited data available from large scale randomized clinical study. Objective: To report incidence of postoperative urinary retention and evaluate the associated risk factors for transanal total mesorectal excision. Design: In this randomized controlled trial (ClinicalTrials. gov NCT06147492), we retrieved 524 patients who received total mesorectal excision (TME) for stage I-III rectal cancer between June 2019 and April 2022, and the patients were randomly assigned in a 1:1 ratio to undergo either taTME or laTME. Patients: We enrolled 524 patients who underwent total mesorectal excision for stage I-III rectal cancer between June 2019 and April 2022. Main outcome measures: The incidence of postoperative urinary retention. Results: Among the 524 enrolled patients, 261 were randomized to the laTME group, while 263 were were randomized the taTME group. The median age was 58 years, and 340 participants (64.8 %) were male. Notably, 37 individuals (7.0 %) experienced postoperative urinary retention during the follow-up period, with no significant disparity was observed between the taTME and laTME groups (6.8 % and 7.2 %, respectively, P = 0.98). Risk factors associated with PUR in patients following taTME encompassed early removal of the urinary catheter (P = 0.006), net infusion rate >4.09 ml kg-1.h-1 (P = 0.006), and an age surpassing 65 years (P = 0.0321). Limitations: The generalizability of the findings outside specialist rectal cancer centers may be limited. Conclusions: Transanal total mesorectal excision was not found to heighten the risk of postoperative urinary retention. Nonetheless, it is advisable removing postoperative catheter beyond the initial day and exercising caution in the administration of intravenous fluids in clinical practice for taTME procedures.

Prognostic factors for local recurrence in patients with rectal cancer submitted to neoadjuvant chemoradiotherapy and total mesorectal excision.

Prognostic factors for local recurrence in patients with rectal cancer submitted to neoadjuvant chemoradiotherapy and total mesorectal excision. BACKGROUND: The standard curative treatment for locally advanced rectal cancer of the middle and lower thirds is long-course chemoradiotherapy followed by total mesorectal excision. PURPOSE: To evaluate the prognostic factors associated with local recurrence in patients with rectal cancer submitted to neoadjuvant chemoradiotherapy and total mesorectal excision. METHODS: Retrospective study including patients with rectal cancer T3-4N0M0 or T (any)N + M0 located within 10 cm from the anal border, or patients with T2N0M0 located within 5 cm, treated by long course chemoradiotherapy followed by total mesorectal excision with curative intent. Clinical, demographic, radiologic, surgical, and anatomopathological data were collected. Local recurrence was estimated using the Kaplan-Meier function, and risk was estimated according to each characteristic using univariate and multivariate analyses. RESULTS: 270 patients were included, 57.8% male and mean age 61.7 (30‒88) years. At initial staging, 6.7% of patients were stage I, 21.5% stage II, and 71.8% stage III. Open surgery was performed in 65.2%, with sphincter preservation in 78.1%. Mortality within 30 postoperative days was 0.7%. After 49.4 (0.5‒86.1) months of median follow-up, overall and local recurrences were 26.3% and 5.9%. On multivariate analyses, local recurrence was associated with involvement of the mesorectal fascia on restaging MRI (HR = 9.11, p = 0.001) and with pathologic involvement of radial surgical margin (HR = 8.19, p < 0.001). CONCLUSION: Local recurrence of rectal cancer treated with long-course chemoradiation and total mesorectal excision is low and is associated with pathologic involvement of the radial surgical margin and can be predicted on restaging MRI.

Clinical application of eight-zone laparoscopic dissection strategy for rectal cancer: Experience and discussion.

BACKGROUND: The incidence of rectal cancer is increasing worldwide, and surgery remains the primary treatment modality. With the advent of total mesorectal excision (TME) technique, the probability of tumor recurrence post-surgery has significantly decreased. Surgeons' focus has gradually shifted towards minimizing the impact of surgery on urinary and sexual functions. Among these concerns, the optimal dissection of the rectal lateral ligaments and preservation of the pelvic floor neurovascular bundle have become critical. To explore the optimal surgical technique for TME and establish a standardized surgical protocol to minimize the impact on urinary and sexual functions, we propose the eight-zone dissection strategy for pelvic floor anatomy. AIM: To compare the differences in surgical specimen integrity and postoperative quality of life satisfaction between the traditional pelvic floor dissection strategy and the innovative eight-zone dissection strategy. METHODS: We analyzed the perioperative data of patients who underwent laparoscopic radical resection of rectal cancer at Qilu Hospital of Shandong University between January 1, 2021 and December 1, 2023. This study included a total of 218 patients undergoing laparoscopic radical surgery for rectal cancer, among whom 109 patients underwent traditional pelvic floor dissection strategy, and 109 patients received the eight-zone dissection strategy. RESULTS: There were no significant differences in general characteristics between the two groups. Patients in the eight-zone dissection group had higher postoperative specimen integrity (88.1% vs 78.0%, P = 0.047). At the 3-month follow-up, patients in the eight-zone surgery group had better scores in urinary issues (6.8 ± 3.3 vs 5.3 ± 2.5, P = 0.045) and male sexual desire (2.2 ± 0.6 vs 2.5 ± 0.5, P = 0.047) compared to the traditional surgery strategy group. CONCLUSION: This study demonstrates that the eight-zone dissection strategy for laparoscopic lateral ligament dissection of rectal cancer is safe and effective. Compared with the traditional pelvic floor dissection strategy, this approach can reduce the risk of nerve injury and minimize the impact on urinary and sexual functions. Therefore, we recommend the clinical application of this strategy to better serve patients with rectal cancer.

Artificial intelligence-assisted decision making: Prediction of optimal level of distal mesorectal margin during transanal total mesorectal excision (taTME) using deep neural network modeling.

BACKGROUND: With steep posterior anorectal angulation, transanal total mesorectal excision (taTME) may have a risk of dissection in the wrong plane or starting higher up, resulting in leaving distal mesorectum behind. Although the distal mesorectal margin can be assessed by preoperative MRI, it needs skilled radiologist and high-definition image for accurate evaluation. This study developed a deep neural network (DNN) to predict the optimal level of distal mesorectal margin. METHODS: A total of 182 pelvic MRI images extracted from the cancer image archive (TCIA) database were included. A DNN was developed using gender, the degree of anterior and posterior anorectal angles as input variables while the difference between anterior and posterior mesorectal distances from anal verge was selected as a target. The predictability power was assessed by regression values (R) which is the correlation between the predicted outputs and actual targets. RESULTS: The anterior angle was an obtuse angle while the posterior angle varied from acute to obtuse with mean angle difference 35.5°±14.6. The mean difference between the anterior and posterior mesorectal end distances was 18.6±6.6mm. The developed DNN had a very close correlation with the target during training, validation, and testing (R=0.99, 0.81, and 0.89, P<0.001). The predicted level of distal mesorectal margin was closely correlated with the actual optimal level (R=0.91, P<0.001). CONCLUSIONS: Artificial intelligence can assist in either making or confirming the preoperative decisions. Furthermore, the developed model can alert the surgeons for this potential risk and the necessity of re-positioning the proctectomy incision.

Comparing total mesorectal excision with partial mesorectal excision for proximal rectal cancer: evaluating postoperative and long-term oncological outcomes.

The treatment role of Total Mesorectal Excision (TME) in proximal rectal cancers (PRC) is still debated. Partial Mesorectal Excision (PME) can reduce morbidity in PRC patients. The purpose of this study was to compare short-term clinical and long-term oncological outcomes between the two groups. A total of 157 PRC patients were enrolled in this study (114 performed with PME and 43 with TME). The two groups were compared in terms of perioperative and long-term oncological outcomes. The overall postoperative complications rate was higher in TME group (18.4% vs. 32.5%, p < 0.05). The incidence of diverting ileostomy was also significantly higher in TME group (86.0% vs. 2.6%, p < 0.001). Overall survival rates for 3, 5, and 7 years in PME and TME group accordingly were: 94.6%, 89.3%, 81.5% and 93.2%, 87.6%, 78.4% (p = 0.324). Disease-free survival rates for 3, 5, and 7 years in PME and TME group were: 90.2%, 84.5%, 78.6% and 88.7%, 81.2%, 75.3% (p = 0.297), respectively. Local recurrence rates for 3, 5, and 7 years in PME and TME group were: 2.6%, 6.1%, 8.8% and 4.6%, 9.3%, 11.2% (p = 0.061), respectively. PME is feasible and can be safely performed in PRC patients with favorable oncological outcomes. TME is associated with increasing risk of surgical complications and requires a two-step surgery for stoma takedown.

Evaluating Postoperative Prognosis: A Single Surgeon's Experience With Total Mesorectal Excision in Middle and Lower Rectal Cancer Cases in Iraq.

INTRODUCTION: Surgical intervention for rectal cancer is widely recognized for its potential to significantly impact quality of life, chiefly due to the high probability of permanent colostomy and the associated postoperative complications. OBJECTIVE: This study aimed to evaluate the short-term outcomes and morbidity associated with total mesorectal excision for middle and lower rectal cancer within an Iraqi cohort, in a prospective setting. METHODS: This study prospectively collected and analyzed data from 89 patients who underwent a standardized radical rectal resection, with a follow-up period extending to one month post-surgery. RESULTS: The mean age of patients was 54.4 ± 12.9 years, with a gender distribution of 46 males and 43 females. A total of 33 patients presented with preoperative comorbidities, which heightened the risk of adverse short-term outcomes by a factor of 7.51. The most prevalent comorbidities were hypertension and diabetes mellitus, affecting 22 and 20 patients, respectively. Patients aged 60 years and above were at a 3.97 times greater risk of developing complications. The overall complication rate was 21.35%, with wound infections (9.0%) and cardiovascular events (3.4%) being the most common. Mortality during the follow-up was 1.1%. CONCLUSION: The findings indicate that increased age and the presence of comorbidities are significant risk factors for morbidity and mortality post-surgery. Neoadjuvant chemoradiotherapy or radiotherapy was shown to reduce morbidity and mortality rates while improving survival. The morbidity and mortality rates observed in this study concur with existing literature.

Major colorectal surgery with Hugo™ RAS: initial experience of a German center and a review of the literature.

The recently introduced Hugo RAS robotic platform has mostly been used for well standardized urologic and gynaecologic procedures. Experience with this new system in general surgery and especially in major colorectal surgery is very limited. This is a retrospective series of the first 25 consecutive non-selected colorectal surgeries performed at a single German center. The lessons learned from our initial experience are presented along with a systematic review of the currently available literature on this topic. Ten sigmoid and seven rectal resections, four right and one left hemicolectomies, two Hartmann's reversals and an abdominoperineal resection were performed in 14 women and 11 men at the median age of 66 years for 12 benign findings and 13 malignancies. All procedures were performed using four robotic ports and a single 12 mm assistant port. Median docking, console and total operative times were 12, 170 and 270 min. Median blood loss was < 100 ml, and median stay was 8 days. The literature review identified five case series with a total of 23 colorectal procedures: 9 right and 1 left hemicolectomies, 5 ileocaecal, and 4 rectal and 4 sigmoid resections. Results corresponded to ours despite variations in setup used by different authors. A wide spectrum of major colorectal surgery can be safely and effectively performed with the Hugo RAS, even in a cohort of non-selected patients. Ongoing software and hardware upgrade, introduction of robotic energy devices and increasing surgical experience are expected to facilitate procedures and reduce duration of surgery.

Efficacy of lateral lymph node dissection for local control of rectal cancer: A multicenter study.

Background: This study aimed to evaluate the efficacy of lateral lymph node dissection (LLND) for rectal cancer by comparing the local control in patients with and without pathological lateral lymph node metastasis (LLNM). Methods: We included 189 patients with rectal cancer who underwent total mesorectal excision and LLND at 13 institutions between 2017 and 2019. Patients with and without pathological LLNM were defined as the pLLNM (+) and (-) groups, respectively. Propensity score-matching helped to balance the basic characteristics of both groups. The incidences of local recurrence (LR) and lateral lymph node recurrence (LLNR) were compared between the groups. Results: In the entire cohort, 39 of the 189 patients had pathological LLNM. The 3-year LR and LLNR rates were 18.3% and 4.0% (p = 0.01) and 7.7% and 3.3% (p = 0.22) in the pLLNM (+) and (-) groups, respectively. After propensity score matching, the data from 62 patients were analyzed. No significant differences in LR or LLNR were observed between both groups. The 3-year LR and LLNR rates were 16.4% and 9.8% (p = 0.46) and 9.7% and 9.8% (p = 0.99) in the pLLNM (+) and (-) groups, respectively. Conclusion: LLND would lead to comparable local control in the pLLNM (+) and (-) groups if the clinicopathological characteristics except for LLNM are similar.

Implementing a no-drain policy for extraperitoneal colorectal anastomosis in a real-life setting: analysis of outcomes and surgeons' adherence.

AIM: Recent evidence has questioned the usefulness of anastomotic drain (AD) after low anterior resection (LAR). However, the implementation and adoption of a no-drain policy are still poor. This study aims to assess the clinical outcomes of the implementation of a no-drain policy for rectal cancer surgery into a real-life setting and the adherence of the surgeons to such policy. METHOD: A retrospective analysis was conducted on patients who underwent elective minimally invasive LAR between January 2015 and December 2019 at two tertiary referral centers. In 2017, both centers implemented a policy aimed at reducing the use of AD. Patients were retrospectively categorized into two groups: the drain policy (DP) group, comprising patients treated before 2017, and the no-drain policy (NDP) group, consisting of patients treated from 2017 onwards. The endpoints were the rate of anastomotic leak (AL) and of related interventions. RESULTS: Among the 272 patients included, 188 (69.1%) were in the NDP group, and 84 (30.9%) were in the DP group. Baseline characteristics were similar between the two groups. AL rate was 11.2% in the NDP group compared to 10.7% in the DP group (p = 1.000), and the AL grade distribution (grade A, 19.1% (4/21) vs 28.6% (2/9); grade B, 28.6% (6/21) vs 11.1% (1/9); grade C, 52.4% (11/21) vs 66.7% (6/9), p = 0.759) did not significantly differ between the groups. All patients with symptomatic AL and AD underwent surgical treatment for the leak, while those with symptomatic AL in the NPD group were managed with surgery (66.7%), endoscopic (19.0%), or percutaneous (14.3%) interventions. Postoperative outcomes were similar between the groups. Three years after implementing the no-drain policy, AD was utilized in only 16.5% of cases, compared to 76.2% at the study's outset. CONCLUSION: The introduction of a no-drain policy received a good adoption rate and did not affect negatively the surgical outcomes.

Functional outcomes and quality of life following open versus laparoscopic versus robot-assisted versus transanal total mesorectal excision in rectal cancer patients: a systematic review and meta-analysis.

BACKGROUND: The standard surgical treatment for rectal cancer is total mesorectal excision (TME), which may negatively affect patients' functional outcomes and quality of life (QoL). However, it is unclear how different TME techniques may impact patients' functional outcomes and QoL. This systematic review and meta-analysis evaluated functional outcomes of urinary, sexual, and fecal functioning as well as QoL after open, laparoscopic (L-TME), robot-assisted (R-TME), and transanal total mesorectal excision (TaTME). METHODS: A systematic review and meta-analysis, based on the preferred reporting items for systematic reviews and meta-analysis statement, were conducted (PROSPERO: CRD42021240851). A literature review was performed (sources: PubMed, Medline, Embase, Scopus, Web of Science, and Cochrane Library databases; end-of-search date: September 1, 2023), and a quality assessment was performed using the Methodological index for non-randomized studies. A random-effects model was used to pool the data for the meta-analyses. RESULTS: Nineteen studies were included, reporting on 2495 patients (88 open, 1171 L-TME, 995 R-TME, and 241 TaTME). Quantitative analyses comparing L-TME vs. R-TME showed no significant differences regarding urinary and sexual functioning, except for urinary function at three months post-surgery, which favoured R-TME (SMD [CI] -0 .15 [- 0.24 to - 0.06], p = 0.02; n = 401). Qualitative analyses identified most studies did not find significant differences in urinary, sexual, and fecal functioning and QoL between different techniques. CONCLUSIONS: This systematic review and meta-analysis highlight a significant gap in the literature concerning the evaluation of functional outcomes and QoL after TME for rectal cancer treatment. This study emphasizes the need for high-quality, randomized-controlled, and prospective cohort studies evaluating these outcomes. Based on the limited available evidence, this systematic review and meta-analysis suggests no significant differences in patients' urinary, sexual, and fecal functioning and their QoL across various TME techniques.

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer.

Colorectal cancer ranks among the most commonly diagnosed cancers globally, and is associated with a high rate of pelvic recurrence after surgery. In efforts to mitigate recurrence, pelvic lymph node dissection (PLND) is commonly advocated as an adjunct to radical surgery. Neoadjuvant chemoradiotherapy (NACRT) is a therapeutic approach employed in managing locally advanced rectal cancer, and has been found to increase the survival rates. Chua et al have proposed a combination of NACRT with selective PLND for addressing lateral pelvic lymph node metastases in rectal cancer patients, with the aim of reducing recurrence and improving survival outcomes. Nevertheless, certain studies have indicated that the addition of PLND to NACRT and total mesorectal excision did not yield a significant reduction in local recurrence rates or improvement in survival. Consequently, meticulous patient selection and perioperative chemotherapy may prove indispensable in ensuring the efficacy of PLND.

Changes to circulating tumor cells in the central vein during laparoscopic versus transanal endoscopic surgeries for rectal cancer: can surgical approach make a difference?

Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Local Recurrence of Rectal Cancer After Transanal Total Mesorectal Excision and Risk Factors: A Nationwide Multicenter Cohort Study in Japan.

Objective: To investigate the oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer and risk factors for local recurrence (LR). Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Long-Term Outcomes of Robotic Versus Laparoscopic Total Mesorectal Excisions: A Propensity-Score Matched Cohort study of 5-year survival outcomes.

Objective: To compare long-term outcomes between laparoscopic and robotic total mesorectal excisions (TMEs) for rectal cancer in a tertiary center. Background: Laparoscopic rectal cancer surgery has comparable long-term outcomes to the open approach, with several advantages in short-term outcomes. However, it has significant technical limitations, which the robotic approach aims to overcome. Methods: We included patients undergoing laparoscopic and robotic TME surgery between 2013 and 2021. The groups were compared after propensity-score matching. The primary outcome was 5-year overall survival (OS). Secondary outcomes were local recurrence (LR), distant recurrence (DR), disease-free survival (DFS), and short-term surgical and patient-related outcomes. Results: A total of 594 patients were included, and after propensity-score matching 215 patients remained in each group. There was a significant difference in 5-year OS (72.4% for laparoscopy vs 81.7% for robotic, P = 0.029), but no difference in 5-year LR (4.7% vs 5.2%, P = 0.850), DR (16.9% vs 13.5%, P = 0.390), or DFS (63.9% vs 74.4%, P = 0.086). The robotic group had significantly less conversion (3.7% vs 0.5%, P = 0.046), shorter length of stay [7.0 (6.0-13.0) vs 6.0 (4.0-8.0), P < 0.001), and less postoperative complications (63.5% vs 50.7%, P = 0.010). Conclusions: This study shows a correlation between higher 5-year OS and comparable long-term oncological outcomes for robotic TME surgery compared to the laparoscopic approach. Furthermore, lower conversion rates, a shorter length of stay, and a less minor postoperative complications were observed. Robotic rectal cancer surgery is a safe and favorable alternative to the traditional approaches.

Association of Surgical Approaches and Outcomes in Total Mesorectal Excision and Margin Status for Rectal Cancer.

INTRODUCTION: Despite being a key metric with a significant correlation with the outcomes of patients with rectal cancer, the optimal surgical approach for total mesorectal excision (TME) has not yet been identified. The aim of this study was to assess the association of the surgical approach on the quality of TME and surgical margins and to characterize the surgical and long-term oncologic outcomes in patients undergoing robotic, laparoscopic, and open TME for rectal cancer. METHODS: Patients with primary, nonmetastatic rectal adenocarcinoma who underwent either lower anterior resection or abdominoperineal resection via robotic (Rob), laparoscopic (Lap), or open approaches were selected from the US Rectal Cancer Consortium database (2007-2017). Quasi-Poisson regression analysis with backward selection was used to investigate the relationship between the surgical approach and outcomes of interest. RESULTS: Among the 664 patients included in the study, the distribution of surgical approaches was as follows: 351 (52.9%) underwent TME via the open approach, 159 (23.9%) via the robotic approach, and 154 (23.2%) via the laparoscopic approach. There were no significant differences in baseline demographics among the three cohorts. The laparoscopic cohort had fewer patients with low rectal cancer (<6 cm from the anal verge) than the robotic and open cohorts (Lap 28.6% versus Rob 59.1% versus Open 45.6%, P = 0.015). Patients who underwent Rob and Lap TME had lower intraoperative blood loss compared with the Open approach (Rob 200 mL [Q1, Q3: 100.0, 300.0] versus Lap 150 mL [Q1, Q3: 75.0, 250.0] versus Open 300 mL [Q1, Q3: 150.0, 600.0], P < 0.001). There was no difference in the operative time (Rob 243 min [Q1, Q3: 203.8, 300.2] versus Lap 241 min [Q1, Q3: 186, 336] versus Open 226 min [Q1, Q3: 178, 315.8], P = 0.309) between the three approaches. Postoperative length of stay was shorter with robotic and laparoscopic approach compared to open approach (Rob 5.0 d [Q1, Q3: 4, 8.2] versus Lap 5 d [Q1, Q3: 4, 8] versus Open 7.0 d [Q1, Q3: 5, 9], P < 0.001). There was no statistically significant difference in the quality of TME between the robotic, laparoscopic, and open approaches (79.2%, 64.9%, and 64.7%, respectively; P = 0.46). The margin positivity rate, a composite of circumferential margin and distal margin, was higher with the robotic and open approaches than with the laparoscopic approach (Rob 8.2% versus Open 6.6% versus Lap 1.9%, P = 0.17), Rob versus Lap (odds ratio 0.21; 95% confidence interval 0.05, 0.83) and Rob versus Open (odds ratio 0.5; 95% confidence interval 0.22, 1.12). There was no difference in long-term survival, including overall survival and recurrence-free survival, between patients who underwent robotic, laparoscopic, or open TME (Figure 1). CONCLUSIONS: In patients undergoing surgery with curative intent for rectal cancer, we did not observe a difference in the quality of TME between the robotic, laparoscopic, or open approaches. Robotic and open TME compared to laparoscopic TME were associated with higher margin positivity rates in our study. This was likely due to the higher percentage of low rectal cancers in the robotic and open cohorts. We also reported no significant differences in overall survival and recurrence-free survival between the aforementioned surgical techniques.

Comparison of local excision and total mesorectal excision for rectal cancer: Systematic review and meta-analysis of randomised controlled trial.

To report the first and largest systematic review and meta-analysis of radomised controlled trials (RCTs) to compare the efficacy and safety of transanal endoscopic microsurgery (TEM) and total mesorectal excision (TME) for rectal cancer for perioperative and oncological outcomes. Methods: We conducted a systematic literature retrieval via PubMed, Embase, Web of Science, and Cochrane until December 2022 for RCTs which evaluated the efficacy and/or safety between TEM and TME for rectal cancer. Outcomes included operative time, blood loss, transfusion rates, hospital stay, complication rates, recurrence rates, and mortality. Results: A total of 5 RCTs involving 545 patients (272 TEM versus 273 TME) were included for the meta-analysis. There were no significant differences between the two groups for age, gender, and distance from lower border of tumor to anal verge. Meta-analysis found that the TEM group was significantly favorable than the TME group for blood loss (WMD: 172.01; 95 % CI: 212.78, -131.24; P < 0.00001), hospital stay (WMD: 2.58; 95 % CI: 3.01, -2.16; P < 0.00001), operative time (WMD: 81.86; 95 % CI: 87.51, -76.21; P < 0.00001) and transfusion rates (RR: 0.05; 95 % CI: 0.01, 0.38; P = 0.004). The complication rates (RR: 0.60; 95 % CI: 0.32, 1.11; P = 0.10), recurrence rates (RR: 1.10; 95 % CI: 0.66, 1.83; P = 0.72), and mortality (RR: 1.23; 95 % CI: 0.67, 2.26; P = 0.51) were similar in the two groups. Conclusions: TEM was an effective and safe approach with advantages in perioperative outcomes compared with TME approach. Caution should be exercised in interpreting the differences in surgical complications between TEM and TME group due to significant heterogeneity and instability.