Techniques in total mesorectal excision surgery

Oncologic outcomes following transanal total mesorectal excision: the United States experience

AIM

The benefits and short-term outcomes of transanal total mesorectal excision (taTME) for rectal cancer have been demonstrated previously, but questions remain regarding the oncologic outcomes following this challenging procedure. The purpose of this study was to analyze the oncologic outcomes following taTME at high-volume centers in the USA.

METHODS

This was a multicenter, retrospective observational study of 8 tertiary care centers. All consecutive taTME cases for primary rectal cancer performed between 2011 and 2020 were included. Clinical, histopathologic, and oncologic data were analyzed. Primary endpoints were rate of local recurrence, distal recurrence, 3-year disease recurrence, and 3-year overall survival. Secondary endpoints included perioperative complications and TME specimen quality.

RESULTS

A total of 391 patients were included in the study. The median age was 57 years (IQR: 49, 66), 68% of patients were male, and the median BMI was 27.4 (IQR: 24.1, 31.0). TME specimen was complete or near complete in 94.5% of cases and the rates of positive circumferential radial margin and distal resection margin were 2.0% and 0.3%, respectively. Median follow-up time was 30.7 months as calculated using reverse-KM estimator (CI 28.1-33.8) and there were 9 cases (2.5%) of local recurrence not accounting for competing risk. The 3-year estimated rate of disease recurrence was 19% (CI 15-25%) and the 3-year estimated overall survival was 90% (CI 87-94%).

CONCLUSION

This large multicenter study confirms the oncologic safety and perioperative benefits of taTME for rectal cancer when performed by experienced surgeons at experienced referral centers.

Management of lateral pelvic lymph nodes in rectal cancer: Is it time to reach an Agreement?

In this editorial, we proceed to comment on the article by Chua et al, addressing the management of metastatic lateral pelvic lymph nodes (mLLN) in stage II/III rectal cancer patients below the peritoneal reflection. The treatment of this nodal area sparks significant controversy due to the strategic differences followed by Eastern and Western physicians, albeit with a higher degree of convergence in recent years. The dissection of lateral pelvic lymph nodes without neoadjuvant therapy is a standard practice in Eastern countries. In contrast, in the West, preference leans towards opting for neoadjuvant therapy with chemoradiotherapy or radiotherapy, that would cover the treatment of this area without the need to add the dissection of these nodes to the total mesorectal excision. In the presence of high-risk nodal characteristics for mLLN related to radiological imaging and lack of response to neoadjuvant therapy, the risk of lateral local recurrence increases, suggesting the appropriate selection of strategies to reduce the risk of recurrence in each patient profile. Despite the heterogeneous and retrospective nature of studies addressing this area, an international consensus is necessary to approach this clinical scenario uniformly.

Measurement that matters: A systematic review and modified Delphi of multidisciplinary colorectal cancer quality indicators

AIM

To develop a priority set of quality indicators (QIs) for use by colorectal cancer (CRC) multidisciplinary teams (MDTs).

METHODS

The review search strategy was executed in four databases from 2009-August 2019. Two reviewers screened abstracts/manuscripts. Candidate QIs and characteristics were extracted using a tailored abstraction tool and assessed for scientific soundness. To prioritize candidate indicators, a modified Delphi consensus process was conducted. Consensus was sought over two rounds; (1) multidisciplinary expert workshops to identify relevance to Australian CRC MDTs, and (2) an online survey to prioritize QIs by clinical importance.

RESULTS

A total of 93 unique QIs were extracted from 118 studies and categorized into domains of care within the CRC patient pathway. Approximately half the QIs involved more than one discipline (52.7%). One-third of QIs related to surgery of primary CRC (31.2%). QIs on supportive care (6%) and neoadjuvant therapy (6%) were limited. In the Delphi Round 1, workshop participants (n = 12) assessed 93 QIs and produced consensus on retaining 49 QIs including six new QIs. In Round 2, survey participants (n = 44) rated QIs and prioritized a final 26 QIs across all domains of care and disciplines with a concordance level > 80%. Participants represented all MDT disciplines, predominantly surgical (32%), radiation (23%) and medical (20%) oncology, and nursing (18%), across six Australian states, with an even spread of experience level.

CONCLUSION

This study identified a large number of existing CRC QIs and prioritized the most clinically relevant QIs for use by Australian MDTs to measure and monitor their performance.

Determination of Factors Related to the Reversal and Perioperative Outcomes of Defunctioning Ileostomies in Patients Undergoing Rectal Cancer Surgery: A Regression Analysis Model

PURPOSE

Defunctioning ileostomies are often performed during rectal cancer surgery. However, stomas are sometimes associated with complications, while 20-30% of them are never reversed. Additionally, ileostomy closure can have associated morbidity, with rates as high as 45%, with the respective literature evidence being scarce and conflicting. Thus, we evaluated the stoma reversal outcomes and the risk factors for non-closure after rectal cancer surgery.

METHODS

This is a retrospective analysis of a prospectively collected database of all patients who had a defunctioning ileostomy at the time of resection for rectal cancer. All operations were performed by the same surgical team. A multivariable regression model was implemented.

RESULTS

In this study, 129 patients (male: 68.2%, female: 31.8%) were included. Ileostomy formation was associated with a total of 31% complication rate. Eventually 73.6% of the stomas were reversed at a mean time to closure of 26.6 weeks, with a morbidity of 13.7%. Non-reversal of ileostomy was correlated with neoadjuvant CRT (OR: 0.093, 95% CI: 0.012-0.735), anastomotic leakage (OR: 0.107, 95% CI: 0.019-0.610), and lymph node yield (OR: 0.946, 95% CI: 0.897-0.998). Time to reversal was affected by the N status, the LNR, the need for adjuvant chemotherapy, and the histologic grade.

CONCLUSION

In patients with rectal cancer resections, defunctioning stoma closure rate and time to closure were associated with several perioperative and pathological outcomes.

Mesentery in Transanal TME

Oncological adequacy in rectal cancer surgery mandates not only a clear distal and circumferential resection margin but also resection of the entire ontogenetic mesorectal package. Incomplete removal of the mesentery is one of the commonest causes of local recurrences. The completeness of the resection is not only determined by tumor and patient related factors but also by the patient-tailored treatment selected by the multidisciplinary team. This is performed in the context of the technical ability and experience of the surgeon to ensure an optimal total mesorectal excision (TME). In TME, popularized by Professor Heald in the early 1980s as a sharp dissection through the avascular embryologic plane, the midline pedicle of tumor and mesorectum is separated from the surrounding, mostly paired structures of the retroperitoneum. Although TME significantly improved the oncological and functional results of rectal cancer surgery, the difficulty of the procedure is still mainly dependent on and determined by the dissection of the most distal part of the rectum and mesorectum. To overcome some of the limitations of working in the narrowest part of the pelvis, robotic and transanal surgery have been shown to improve the access and quality of resection in minimally invasive techniques. Whatever technique is chosen to perform a TME, embryologically derived planes and anatomical points of reference should be identified to guide the surgery. Standardization of the chosen technique, widespread education, and training of surgeons, as well as caseloads per surgeon, are important factors to optimize outcomes. In this article, we discuss the introduction of transanal TME, with emphasis on the mesentery, relevant anatomy, standard procedural steps, and importance of a training pathway.

Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study

BACKGROUND

In rectal cancer surgery, larger mesorectal fat area has been shown to correlate with increased intraoperative difficulty. Prior studies were mostly in Asian populations with average body mass indices (BMIs) less than 25 kg/m². This study aimed to define the relationship between radiological variables on pelvic magnetic resonance imaging (MRI) and intraoperative difficulty in a North American population.

METHODS

This is a single-center retrospective cohort study analyzing all patients who underwent low anterior resection (LAR) or transanal total mesorectal excision (TaTME) for stage I-III rectal adenocarcinoma from January 2015 until December 2019. Eleven pelvic magnetic resonance imaging measures were defined a priori according to previous literature and measured in each of the included patients. Operative time in minutes and intraoperative blood loss in milliliters were utilized as the primary indicators of intraoperative difficulty.

RESULTS

Eighty-three patients (39.8% female, mean age: 62.4 ± 11.6 years) met inclusion criteria. The mean BMI of included patients was 29.4 ± 6.2 kg/m². Mean operative times were 227.2 ± 65.1 min and 340.6 ± 78.7 min for LARs and TaTMEs, respectively. On multivariable analysis including patient, tumor, and MRI factors, increasing posterior mesorectal thickness was significantly associated with increased operative time (p = 0.04). Every 1 cm increase in posterior mesorectal thickness correlated with a 26 min and 6 s increase in operative time. None of the MRI measurements correlated strongly with BMI.

CONCLUSION

As the number of obese rectal cancer patients continues to expand, strategies aimed at optimizing their surgical management are paramount. While increasing BMI is an important preoperative risk factor, the present study identifies posterior mesorectal thickness on MRI as a reliable and easily measurable parameter to help predict operative difficulty. Ultimately, this may in turn serve as an indicator of which patients would benefit most from pre-operative resources aimed at optimizing operative conditions and postoperative recovery.

Total Mesorectal Excision Technique-Past, Present, and Future

While the treatment of rectal cancer is multimodal, above all, a proper oncological resection is critical. The surgical management of rectal cancer has substantially evolved over the past 100 years, and continues to progress as we seek the best treatment. Rectal cancer was historically an unsurvivable disease, with poor understanding of the embryological planes, lymphatic drainage, and lack of standardized technique. Major improvements in recurrence, survival, and quality of life have resulted from advances in preoperative staging, pathologic assessment, the development and timing of multimodal therapies, and surgical technique. The most significant contribution in advancing rectal cancer care may be the standardization and widespread implementation of total mesorectal excision (TME). The TME, popularized by Professor Heald in the early 1980s as a sharp, meticulous dissection of the tumor and mesorectum with all associated lymph nodes through the avascular embryologic plane, has shown universal reproducible reductions in local recurrence and improvement in disease-free and overall survival. Widespread education and training of surgeons worldwide in the TME have significantly impact outcomes for rectal cancer surgery, and the procedure has become the gold standard for curative resection of rectal cancer. In this article, we discuss the evolution of the standard abdominal approach to the TME, with emphasis on the history, relevant anatomy, standard procedure steps, oncologic outcomes, and technical evolution.

Oncological adequacy of laparoscopic rectal cancer resection: An audit in Indian perspective

Background:

Laparoscopic resection for rectal cancer (LRR) has gained popularity because of better short-term outcomes and less post-operative morbidity. However, LRR is still not endorsed as a standard of care mainly due to concerns centred on oncological safety in comparison with open approach. Moreover, two recent randomised trials (Australian Laparoscopic Cancer of the Rectum [ALaCaRT] and the American College of Surgeons Oncology Group [ACOSOG] Z6051) have failed to prove that LRR is non-inferior to open resection. Studies on oncological adequacy of LRR in the Indian population in terms of quality of mesorectal excision are scarce. In this article, we aim to audit the oncological adequacy of LRR in our centre and thereby critically analyse the reliability of extrapolation of results of ALaCaRT and ACOSOG trials to the Indian population.

Methods:

We retrospectively analysed the oncological adequacy of LRR in terms of completeness of total mesorectal excision (TME), distal and circumferential resection margin (CRM) status and nodal harvest in patients with rectal cancer who underwent LRR between January 2016 and June 2018 at our centre.

Results:

Of 157 patients included in this study, a complete TME was achieved in 148 (94.26%) patients and nearly complete in 7 (4.46%) patients. A safe CRM (≥1 mm) was obtained in 151 (96.18%) patients. Distal margin results were negative in 155 (98.73%) patients. Average nodal harvest was 19.86 ± 9.28. Overall surgical success, calculated as a composite measure of negative distal margin and negative CRM and complete TME was 95.54%.

Conclusion:

Good quality rectal cancer resection can be achieved by experienced laparoscopic surgeons without compromising oncological safety.

Short- and long-term outcomes of transanal versus laparoscopic total mesorectal excision for mid-to-low rectal cancer: a meta-analysis

BACKGROUND AND OBJECTIVES

Transanal total mesorectal excision (TaTME) is positioned at the cutting edge of minimally invasive approach to mid- and low rectal cancer. This meta-analysis was to compare the short- and long-term outcomes of TaTME versus laparoscopic total mesorectal excision (LTME) and to evaluate the safety, efficacy, and possible superiority of TaTME.

METHODS

A comprehensive search was conducted for randomized controlled trials (RCTs) and non-RCTs (NRCTs) comparing TaTME with LTME. Inter-group differences were evaluated via standardized mean differences and relative risks (RRs). All outcomes were analyzed using fixed effects or random effects models according to the heterogeneity. Statistical analysis was performed using Stata/SE 12.0 software.

RESULTS

Eleven studies (1 RCT and 10 NRCTs) with involving 757 patients were included. Among which, 361 patients underwent TaTME and 396 patients underwent LTME. Comparing the surgical and oncological quality of resection of TaTME with that of LTME, reports of TaTME indicated favorable outcomes considering mesorectal resection quality, circumferential resection margin involvement, intraoperative blood loss, conversions, and postoperative complications, while the differences between the two groups had no statistical significance in terms of distal resection margin, harvested lymph node, operation time, hospital stay, recurrence, 2-year overall survival (OS), and 2-year disease-free survival.

CONCLUSION

TaTME is a promising surgical technique and is fully a safe, efficacious, and diffusible alternative to LTME in managing mid- and distal rectal cancer. Larger scale, national, multicentric RCTs are warranted to further verify these results and the possible superiority of TaTME.

Defining the distal margin of rectal cancer for surgical planning

Accurate measurement of the distal rectal tumor margin is essential in selecting the appropriate surgical procedure. However, there is no standard measurement method. The National Cancer Institute consensus group recommends use of the anal verge (AV) as a landmark, and the European Society of Gastrointestinal and Abdominal Radiology recommends use of the anorectal ring (ARR). In addition, whether measurements should be made on double contrast barium enema (BE) radiographs or magnetic resonance (MR) images remains controversial. We measured the distal tumor margin on both BE and MR images obtained preoperatively from 52 patients who underwent sphincter-saving resection for rectal cancer. The distances from the distal end of the tumor to the AV and the ARR were measured on both types of images, and the variability was investigated by Bland-Altman analysis. The mean distance from the tumor to the AV was 8.9 cm on the BE radiographs and 7.7 cm on the MR images (P=0.013). The mean distances to the ARR were 6.8 and 5.6 cm, respectively (P=0.070). Significant proportional bias was shown as the measured distances increased, the difference between the BE- and magnetic resonance imaging (MRI)-based measurements increased. Use of one or the other landmark did not affect selection of the appropriate surgical procedure. We conclude that an approximate 1-cm underestimation should be taken into account when MRI-based measurement of the distal rectal tumor margin is used to choose between sphincter-saving resection and abdominoperineal resection.

Comparison of short-term clinical outcomes between transanal and laparoscopic total mesorectal excision for the treatment of mid and low rectal cancer: A meta-analysis

AIM

The objective of this meta-analysis was to evaluate the feasibility, safety, and short-term clinical outcomes of transanal total mesorectal excision (TaTME) comparing with laparoscopy total mesorectal excision (LapTME) for mid and low rectal cancer.

METHODS

Relevant studies were searched from the databases of Pubmed, Embase, and the Cochrane Library. The qualities of all of the included studies were evaluated using Newcastle-Ottawa Scale (NOS). The synthesized outcomes were pooled using fixed-effects models or random-effects models, which weighted the odds ratio (OR) or mean difference (MD) with 95% confidence intervals (95% CI). A funnel plot was used to evaluate the publication bias.

RESULTS

Seven original studies including 209 TaTME patients and 257 LapTME patients with rectal cancer met the inclusion criteria in this meta-analysis. Compared with LapTME, TaTME showed a longer CRM, lower rate of positive CRM, complete TME rate, and less operative time. There were no significant differences in the outcomes of the harvested lymph nodes, distal margin distance, hospital stay, intraoperative complications, anastomotic leakage, postoperative complications, reoperation, readmission, or conversion between the TaTME group and the LapTME group.

CONCLUSIONS

Compared with LapTME, TaTME is a feasible and safe approach for patients with mid and low rectal cancer. In addition, TaTME showed a better short-term clinical outcomes, such as a longer CRM, lower risk of positive CRM, higher complete quality of TME rate, and shorter operative duration. Further prospective studies with long-term follow-up are required.

A review on robotic surgery in rectal cancer

Robotic surgery has the upper hand when compared to the laparoscopic approach in terms of superior visualisation, flexibility in movement, steadiness and accessibility to confined anatomical spaces. Nevertheless, limitations still exist with regards to cost, reduced tactile sensation, time-consuming setup and a significant learning curve to achieve. Although studies have shown better or at least comparable outcomes between the robotic and laparoscopic approach, the limitations mentioned result in poor penetrance among centres and surgeons. Advancements in robotic surgery technology and attaining the acquired skillset will translate into better clinical outcomes for patients.