Meta-analysis of the impact of surgical approach on the grade of mesorectal excision in rectal cancer

Meta-analysis of randomized clinical trials comparing robotic versus laparoscopic surgery for mid-low rectal cancers

INTRODUCTION

Robotic surgery (RS) is experiencing major development, particularly in the context of rectal cancer. The aim of this meta-analysis was to summarize data from the literature, focusing specifically on the safety and effectiveness of robotic surgery in mid-low rectal cancers, based on the hypothesis that that robotic surgery can find its most rational indication in this anatomical location.

METHOD

The meta-analysis was conducted according to the PRISMA 2000 recommendations, including all randomized trials that compared robotic surgery versus laparoscopic surgery (LS) that were found in the Medline-PICO, Cochrane Database, Scopus and Google databases. Data were extracted independently by two reviewers. The risk of bias was analyzed according to the Cochrane Handbook method and the certainty of the evidence according to the GRADE method. The analysis was carried out with R software Version 4.2-3 using the Package for Meta-Analysis "meta" version 6.5-0.

RESULTS

Eight randomized trials were included (with a total of 2342 patients), including four that focused specifically on mid-low rectal cancer (n=1,734 patients). No statistically significant difference was found for overall morbidity, intra-operative morbidity, anastomotic leakage, post-operative mortality, quality of mesorectal specimen, and resection margins. The main differences identified were a lower conversion rate for RS (RR=0.48 [0.24-0.95], p=0.04, I2=0%), and a longer operative time for RS (mean difference=39.11min [9.39-68.83], p<0.01, I2=96%). The other differences had no real clinical relevance, i.e., resumption of flatus passage (5hours earlier after RS), and lymph node dissection (one more lymph node for LS).

CONCLUSION

This meta-analysis does not confirm the initial hypothesis and does not show a statistically significant or clinically relevant benefit of RS compared to LS for mid-low rectal cancer.

Transanal Total Mesorectal Excision With Delayed Coloanal Anastomosis (TaTME-DCAA) Versus Laparoscopic Total Mesorectal Excision (LTME) and Robotic Total Mesorectal Excision (RTME) for Low Rectal Cancer: A Propensity Score-Matched Analysis of Short-term Outcomes, Bowel Function, and Cost

INTRODUCTION

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Robotic versus laparoscopic low anterior resection following neoadjuvant chemoradiation therapy for stage II-III locally advanced rectal cancer: a single-centre cohort study

Neoadjuvant chemo-radiotherapy (nCRT) of locally advanced rectal cancer is associated with challenging surgical treatment and increased postoperative morbidity. Robotic technology overcomes laparoscopy limitations by enlarged 3D view, improved anatomical transection accuracy, and physiologic tremor reduction. Patients with UICC stage II-III rectal cancer, consecutively referred to our institution between March 2015 and June 2020 (n = 102) were treated with robotic (Rob-G, n = 38) or laparoscopic (Lap-G, n = 64) low anterior resection (LAR) for total meso-rectal excision (TME) following highly standardized and successful nCRT treatment. Feasibility, conversion rates, stoma creation, morbidity and clinical/pathological outcome were comparatively analysed. Sex, age, BMI, ASA scores, cTN stages and tumour distance from dentate line were comparable in the two groups. Robotic resection was always feasible without conversion to open surgery, which was necessary in 11/64 (17%) Lap-G operations (p = 0.006). Primary or secondary stomata were created in 17/38 (45%) Rob-G and 52/64 (81%) Lap-G patients (p < 0.001). Major morbidity occurred in 7/38 (18.4%) Rob-G and 6/64 (9.3%) Lap-G patients (p = 0.225). Although median operation time was longer in Rob-G compared with Lap-G (376; IQR: 330-417 min vs. 300; IQR: 270-358 min; p < 0.001), the difference was not significant in patients (Rob-G, n = 6; Lap-G, n = 10) with ≥30 BMI (p = 0.106). Number of resected lymph nodes, ypTN staging and circumferential resection margins (CRM) were comparable. Resection was complete in 87% of Rob-G and 89% of Lap-G patients (p = 0.750). Robotic LAR is not inferior to laparoscopic LAR following nCRT. Larger, randomized studies are needed to confirm lower conversion in robotic, compared to laparoscopic resection.

Comparison of Survival Among Adults With Rectal Cancer Who Have Undergone Laparoscopic vs Open Surgery: A Meta-analysis

IMPORTANCE

Two large randomized clinical trials (RCTs) found that laparoscopic surgery failed to yield noninferior pathologic outcomes compared with open surgery for patients with rectal cancer. The results raised concerns regarding the effectiveness of the laparoscopic approach for patients with rectal cancer.

OBJECTIVE

To compare the long-term oncologic outcomes of laparoscopic and open surgery for patients with rectal cancer.

DATA SOURCES

PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials were searched from database inception to August 13, 2021. Studies published in English were retrieved.

STUDY SELECTION

The meta-analysis included RCTs that compared laparoscopic surgery with open surgery for patients with rectal cancer and reported the outcome of disease-free survival (DFS) or overall survival (OS). The following exclusion criteria were used: (1) non-RCTs, (2) studies without long-term survival outcomes of interest, and (3) studies that did not report Kaplan-Meier survival curves.

DATA EXTRACTION AND SYNTHESIS

This meta-analysis was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline for individual participant data development groups. Individual participant data on DFS and OS were extracted from the published Kaplan-Meier survival curves. One-stage and 2-stage meta-analyses were performed.

MAIN OUTCOMES AND MEASURES

Meta-analyses were conducted for DFS and OS. Hazard ratios (HRs) were used as effective measures.

RESULTS

Of 8471 records screened, 10 articles with 12 RCTs and 3709 participants were selected. The reconstructed survival curves for the combined population showed that the 5-year estimated DFS rates were 72.2% (95% CI, 69.4%-74.8%) for the laparoscopic group and 70.1% (95% CI, 67.0%-73.0%) for the open surgery group, and the 5-year estimated OS rates were 76.2% (95% CI, 73.8%-78.5%) for the laparoscopic group and 72.7% (95% CI, 69.8%-75.3%) for open surgery group. In 1-stage meta-analyses, DFS had a nonsignificant HR of 0.92 (95% CI, 0.80-1.06; P = .26), which suggested that DFS in the laparoscopic and open surgery groups was comparable; however, OS was significantly better in the laparoscopic group (HR, 0.85; 95% CI, 0.74-0.97; P = .02). The results were confirmed by 2-stage meta-analyses and were validated by sensitivity analysis with large RCTs.

CONCLUSIONS AND RELEVANCE

A similar DFS but significantly better OS were found for patients who have undergone laparoscopic surgery compared with open surgery for rectal cancer. These findings address concerns regarding the effectiveness of laparoscopic surgery and support the routine use of laparoscopic surgery for patients with rectal cancer.

Mid- and low-rectal cancer: laparoscopic vs open treatment-short- and long-term results. Meta-analysis of randomized controlled trials

BACKGROUND

The laparoscopic approach in the treatment of mid- or low-rectal cancer is still controversial. Compared with open surgery, laparoscopic resection of extraperitoneal cancer is associated with improved short-time non-oncological outcomes, although high-level evidence showing similar short- and long-term oncological outcomes is scarce.

OBJECTIVE

The aim of our paper is to study the oncological and non-oncological outcomes of laparoscopic versus open surgery for extraperitoneal rectal cancer.

DATA SOURCES

A systematic review of MedLine, EMBASE, and CENTRAL from January 1990 to October 2020 was performed by combining various key words.

STUDY SELECTION

Only randomized controlled trials (RCTs) comparing laparoscopic versus open surgery for extraperitoneal rectal cancer were included. The quality of RCTs was assessed using the Cochrane reviewer's handbook. This meta-analysis was based on the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

INTERVENTION(S)

This study analyzes laparoscopic versus open surgery for extraperitoneal rectal cancer.

MAIN OUTCOME MEASURES

Primary outcomes were oncological parameters.

RESULTS

Fifteen RCTs comprising 4,411 patients matched the selection criteria. Meta-analysis showed a significant difference between laparoscopic and open surgery in short-time non-oncological outcomes. Although laparoscopic approach increased operation time, it decreases significantly the blood loss and length of hospital stay. No significant difference was noted regarding short- and long-term oncological outcomes, but 4 and 5 years disease-free survival were statistically higher in the open group.

LIMITATIONS

There are still questions about the long-term oncological outcomes of laparoscopic surgery for extraperitoneal rectal cancer being comparable to the open technique.

CONCLUSIONS

Considering that all surgical resections have been performed in high volume centers by expert surgeons, the minimally invasive surgery in patients with extraperitoneal cancer could still be not considered equivalent to open surgery in terms of oncological radicality.

Laparoscopic intraarterial catheterization with selective ICG fluorescence imaging in colorectal surgery

The quality of mesorectal resection is crucial for resection in rectal cancer, which should be performed by laparoscopy for better outcome. The use of indocyanine green (ICG) fluorescence is now routinely used in some centers to evaluate bowel perfusion. Previous studies have demonstrated in animal models that selective intra-arterial ICG staining can be used to define and visualize resection margins in rectal cancer. In this animal study, we investigate if laparoscopic intra-arterial catheterization is feasible and the staining of resection margins when performing total mesorectal excision with a laparoscopic medial to lateral approach is possible. In 4 pigs, laparoscopic catheterization of the inferior mesenteric artery (IMA) is performed using a seldinger technique. After a bolus injection of 10 ml ICG with a concentration of 0.25 mg/ml, a continuous intra-arterial perfusion was established at a rate of 2 ml/min. The quality of the staining was evaluated qualitatively. Laparoscopic catheterization was possible in all cases, and the average time for this was 30.25 ± 3.54 min. We observed a significant fluorescent signal in all areas of the IMA supplied, but not in other parts of the abdominal cavity or organs. In addition, the mesorectum showed a sharp border between stained and unstained tissue. Intraoperative isolated fluorescence augmentation of the rectum, including the mesorectum by laparoscopic catheterization, is feasible. Inferior mesenteric artery catheterization and ICG perfusion can provide a fluorescence-guided roadmap to identify the correct plane in total mesorectal excision, which should be investigated in further studies.

Comparison of Short-Term and Long-Term outcomes of Laparoscopy Versus Laparotomy in Rectal Cancer: Systematic Review and Meta-analysis of Randomized Controlled Trials

Background and objective: The last randomized controlled trials ,the ACOSOG Z6051 1,2 and the ALaCaRT trial3, 4 could not show the non-inferiority of the laparoscopy in comparison to laparotomy for rectal cancer. In fact, the ten first years of practicing laparoscopy were years when surgeons developed their learning curve. Therefore, by excluding this learning bias, it is possible to end up with a more fair and correct comparison between the two techniques. It is henceforth relevant to pursue a new meta-analysis that compares the two techniques and excludes studies done during the earlier periods of laparoscopic rectal surgery. Results: Six randomized controlled trials met the eligibility criteria, involving a total of 1556 patients in the laparoscopy group and 1188 patients in the laparotomy group. Our meta-analysis was in favor of laparoscopy in a significant way for blood loss, first bowel movement and the number of harvested lymph nodes. It was non-significantly in favour of laparoscopy for 30-days mortality after surgery and length of hospital stay. It was significantly in favor of laparotomy for operative duration. No significant difference was found in anastomotic leakage) , reoperation within 30 days, number of positive CRMs and completeness of mesorectal excision between the two groups. No difference was found in recurrence, disease-free survival and overall survival between laparoscopy group and laparotomy group. Conclusion: The comparison of the randomized controlled trials published before and after 2010, showed no significant difference in outcomes between the learning period and after. Keywords: Laparoscopy, laparotomy, long-term outcomes, meta-analysis, short-term outcomes, rectal cancer

Open versus laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy (COREAN trial): 10-year follow-up of an open-label, non-inferiority, randomised controlled trial

BACKGROUND

Laparoscopic surgery has been widely used for rectal cancer; however, its long-term outcomes remain controversial. This study aimed to assess the long-term oncological safety of laparoscopic surgery for rectal cancer using 10-year follow-up data of the Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial.

METHODS

The COREAN trial is a, open-label, non-inferiority, randomised controlled trial. Eligible participants were aged 18-80 years, had cT3N0-2M0 middle or low rectal cancer with lesions located within 9 cm of the anal verge, and had been treated with preoperative chemoradiotherapy. Patients were randomly assigned (1:1) to open or laparoscopic surgery with a computer-generated random allocation sequence with a random permuted block design. Neither patients nor clinicians were masked to treatment assignment. Open or laparoscopic total mesorectal excision was done 6-8 weeks after the administration of preoperative concurrent chemoradiotherapy (fluoropyrimidines alone, doublet therapy, or triplet therapy) at a dose of 50·5 Gy over 5·5 weeks. Postoperative adjuvant chemotherapy was administered for 4 months. The primary endpoint of 3-year disease-free survival was published previously. Here, we report 10-year overall survival, disease-free survival, and local recurrence. Analyses were done in the modified intention-to-treat population of all participants who were randomly assigned and provided follow-up data. This study is registered with ClinicalTrials.gov, NCT00470951.

FINDINGS

Of the 340 patients enrolled in the COREAN trial between April 4, 2006, and Aug 26, 2009 (170 patients in each group), two patients in the laparoscopic surgery group moved abroad and were lost to follow-up, so were not included in this 10-year analysis. The median duration of follow-up was 143 months (IQR 122-156). No differences were observed in 10-year overall survival (74·1% [95% CI 66·8-80·0] in the open surgery group vs 76·8% [69·6-82·5] in the laparoscopic surgery group; p=0·44), 10-year disease-free survival (59·3% [51·1-66·5] vs 64·3% [56·0-71·5]; p=0·20), or 10-year local recurrence (8·9% [5·2-15·0] vs 3·4% [1·4-7·9]; p=0·050) between the open surgery and laparoscopic surgery groups at 10 years after surgery. The stratified hazard ratios, adjusted for ypT and ypN classification and tumour regression grade, for open surgery versus laparoscopic surgery were 0·94 (95% CI 0·63-1·43) for overall survival, 1·05 (0·74-1·49) for disease-free survival, and 2·22 (0·78-6·34) for local recurrence.

INTERPRETATION

The 10-year follow-up of the COREAN trial confirms the long-term oncological safety of laparoscopic surgery in patients with rectal cancer treated with preoperative chemoradiotherapy. Similar to open surgery, laparoscopic surgery does not compromise long-term survival outcomes in rectal cancer when performed by well trained surgeons.

FUNDING

National Cancer Center, Goyang, South Korea.

Oncological outcomes of laparoscopic versus open rectal cancer resections: meta-analysis of randomized clinical trials

BACKGROUND

The role of laparoscopic rectal cancer surgery has been questioned owing to conflicting reports on pathological outcomes from recent RCTs. However, it is unclear whether these pathological markers and the surgical approach have an impact on oncological outcomes. This study assessed oncological outcomes of laparoscopic and open rectal cancer resections.

METHODS

A meta-analysis of RCTs was performed. Primary endpoints included oncological outcomes (disease-free survival (DFS), overall survival (OS), local recurrence). Secondary endpoints included surrogate markers for the quality of surgical resection.

RESULTS

Twelve RCTs including 3744 patients (2133 laparoscopic, 1611 open) were included. There was no significant difference in OS (hazard ratio (HR) 0.87, 95 per cent c.i. 0.73 to 1.04; P = 0.12; I2 = 0 per cent) and DFS (HR 0.95, 0.81 to 1.11; P = 0.52; I2 = 0 per cent) between laparoscopic and open rectal resections. There was no significant difference in locoregional (odds ratio (OR) 1.03, 95 per cent c.i. 0.72 to 1.48; P = 0.86; I2 = 0 per cent) or distant (OR 0.87, 0.70 to 1.08; P = 0.20; I2 = 7 per cent) recurrence between the groups. Achieving a successful composite score (intact mesorectal excision, clear circumferential resection margin and distal margin) was significantly associated with improved DFS (OR 0.55, 0.33 to 0.74; P < 0.001; I2 = 0 per cent). An intact or acceptable mesorectal excision (intact mesorectal excision with or without superficial defects) had no impact on DFS. Finally, a positive CRM was associated with worse DFS.

CONCLUSION

Well performed surgery (laparoscopic or open) achieves excellent oncological outcomes with very little difference between the two modalities. The advantage and benefit of minimally invasive surgery should be assessed on an individual basis.

Obese patients and robotic colorectal surgery: systematic review and meta-analysis

BACKGROUND

Obesity is a major health problem, demonstrated to double the risk of colorectal cancer. The benefits of robotic colorectal surgery in obese patients remain largely unknown. This meta-analysis evaluated the clinical and pathological outcomes of robotic colorectal surgery in obese and non-obese patients.

METHODS

MEDLINE, Embase, Global Health, Healthcare Management Information Consortium (HMIC) and Midwives Information and Resources Service (MIDIRS) databases were searched on 1 August 2018 with no language restriction. Meta-analysis was performed according to PRISMA guidelines. Obese patients (BMI 30 kg/m2 or above) undergoing robotic colorectal cancer resections were compared with non-obese patients. Included outcome measures were: operative outcomes (duration of surgery, conversion to laparotomy, blood loss), postoperative complications, hospital length of stay and pathological outcomes (number of retrieved lymph nodes, positive circumferential resection margins and length of distal margin in rectal surgery).

RESULTS

A total of 131 full-text articles were reviewed, of which 12 met the inclusion criteria and were included in the final analysis. There were 3166 non-obese and 1420 obese patients. A longer duration of surgery was documented in obese compared with non-obese patients (weighted mean difference -21·99 (95 per cent c.i. -31·52 to -12·46) min; P < 0·001). Obese patients had a higher rate of conversion to laparotomy than non-obese patients (odds ratio 1·99, 95 per cent c.i. 1·54 to 2·56; P < 0·001). Blood loss, postoperative complications, length of hospital stay and pathological outcomes were not significantly different in obese and non-obese patients.

CONCLUSION

Robotic surgery in obese patients results in a significantly longer duration of surgery and higher conversion rates than in non-obese patients. Further studies should focus on better stratification of the obese population with colorectal disease as candidates for robotic procedures.

Are oncological long-term outcomes equal after laproscopic completed and converted laparoscopic converted rectal resection for cancer?

BACKGROUND

The aim of this study was to compare long-term survival after laproscopic completed and laparoscopic converted rectal resection for cancer.

METHODS

All consecutive patients who underwent curative laparoscopic rectal surgery for cancer at our institution between January 2001 and December 2016 were included in a single-center retrospective study. Patients were divided into two groups: the converted (CONV) group and the totally laparoscopic (LAP) group. The primary outcomes were long-term oncologic outcomes including overall survival (OS) and disease-free survival (DFS), as well as local and distant recurrence (LR, DR). The secondary outcomes included postoperative mortality and morbidity as defined as death or any complication occurring within 90 days postoperatively.

RESULTS

Of 214 consecutive patients included, 57 were converted to open surgery (CONV group), leading to a 26.6% conversion rate. Mean length of follow-up was 68 ± 42 months in the LAP group and 70 ± 41 months in the CONV group. Five-year OS was significantly shorter in the CONV group compared to the LAP group (p = 0.0016). On multivariate analysis, rectal tumor location (middle and low) and conversion to open surgery were predictors of both OS and DFS.

CONCLUSIONS

This study suggests that conversion to open surgery after laparoscopic rectal resection appears to significantly reduce OS without having a significant impact on DFS and recurrence rates.

Delivery of Personalized Care for Locally Advanced Rectal Cancer: Incorporating Pathological, Molecular Genetic, and Immunological Biomarkers Into the Multimodal Paradigm

Approximately one-third of all newly diagnosed colorectal cancer (CRC) is composed of rectal cancer, with the incidence rising in younger patients. The principal neoadjuvant treatments consist of neoadjuvant short-course radiotherapy and long-course chemoradiation. Locally advanced rectal cancer (LARC) is particularly challenging to manage given the anatomical constrictions of the pelvis and the risk for local recurrence. In appropriately treated patients, 5- and 10-year overall survival is estimated at 60 and 50%, respectively. The prognosis for LARC has improved in recent years with more access to screening, advances in surgical techniques, and perioperative care. Furthermore, the refinement of the multidisciplinary team with combined-modality management strategies has improved outcomes. These advancements have been augmented by significant improvements in the understanding of the underlying tumor biology. However, there are many instances where patient outcomes do not match those for their tumor stage and accurate prognostic information for individual patients can be difficult to estimate owing to the heterogeneous nature of LARC. Many new combinations of chemotherapy with radiotherapy, including total neoadjuvant therapy with targeted therapies that aim to diminish toxicity and increase survival, are being evaluated in clinical trials. Despite these advances, local recurrence and distant metastasis remain an issue, with one-third of LARC patients dying within 5 years of initial treatment. Although much of the new pathological, molecular genetics, and immunological biomarkers allow refinement in the classification and prognostication of CRC, the relative importance of each of these factors with regards to the development and progression of LARC remains incompletely understood. These factors are often insufficiently validated and seldom consider the individual characteristics of the host, the tumor and its location, the local available expertise, or the probable location of recurrence. Appreciating the mechanisms behind these differences will allow for a more comprehensive, personalized approach and more informed treatment options, leading to ultimately superior outcomes. This review aims to first outline the current multidisciplinary context in which LARC care should be delivered and then discuss how some key prognosticators, including novel histopathological, molecular genetics, and immunological biomarkers, might fit into the wider context of personalized LARC management in the coming years.

Laparoscopic Approach to Rectal Cancer-The New Standard?

Minimally invasive surgery has revolutionized the way surgeons perform colorectal surgery, and new technologies continually upend the way surgeons view and operate within the deep pelvis. Among other benefits, it is associated with decreased lengths of stay, wound and surgical site infections, pain scores, and has an overall lower complication rate vs. open surgery (1). Recently, however, the role of minimally invasive surgery has been called into question in the effective and safe treatment of rectal cancer. This manuscript will outline the history of minimally invasive rectal cancer surgery, examine evidence detailing its safety (compared with alternatives), and discuss important aspects of use, most notably the considerable learning curve required to achieve proficiency, the extent of its current use, and potential pitfalls. The current evidence suggests minimally invasive surgery is a very safe way to treat rectal cancer when performed by experienced and specialty trained surgeons.

Surgical approach for rectal cancer: A network meta-analysis comparing open, laparoscopic, robotic and transanal TME approaches

BACKGROUND

The optimal approach for total mesorectal excision (TME) of rectal cancer remains controversial.

AIM

To compare short- and long-term outcomes after open (OpTME), laparoscopic (LapTME), robotic (RoTME) and transanal TME (TaTME).

METHODS

A systematic search of electronic databases was performed up to January 1, 2020 for randomized controlled trials (RCTs) comparing at least 2 TME strategies. A Bayesian arm-based random effect network meta-analysis (NMA) was performed, specifically, a mixed treatment comparison (MTC).

RESULTS

30 RCTs (and six updates) of 5586 patients with rectal cancer were included. No significant differences were identified in recurrence rates or survival rates. Operating time was shorter with OpTME (surface under the cumulative ranking curve [SUCRA] 0.96) compared to LapTME, RoTME and TaTME. Although OpTME was associated with the most blood loss (SUCRA 0.90) and had a slower recovery with increased length of stay (SUCRA 0.90) compared to the minimally invasive techniques, there was no difference in postoperative morbidity. OpTME was associated with a more complete TME specimen compared to LapTME (Risk Ratio [RR] 1.05, 95% Credible Interval [CrI] 1.01, 1.11), and TaTME had less involved CRMs (RR 0.173, 95% CrI 0.02, 0.76) versus LapTME. There were no differences between the modalities in terms of deep TME defects, DRM distance, or lymph node yield.

CONCLUSIONS

While OpTME was the most effective TME modality for short term histopathological resection quality, there was no difference in long-term oncologic outcomes. Minimally invasive approaches enhance postoperative recovery, at the cost of longer operating times. Technique selection should be based on individual tumour characteristics and patient expectations, as well as surgeon and institutional expertise.

Intra-arterial versus negative-staining of embryonal resection borders with indocyanine green (ICG) fluorescence for total mesorectal excision in colorectal cancer - an experimental feasibility study in a porcine model

Background: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Laparoscopic lower rectal resections in accordance with the oncological principles are recommended as the gold standard for CRC surgical management. However, the learning curve for adopting these techniques is quite steep and the incomplete resections are predictive of local recurrence. This study was conducted in an attempt to find a way to help surgeons to overcome some of these difficulties and define the right resection margins.Material and methods: As such, we carried out two laparoscopic lower rectal resections in porcine models. The first resection was performed following the ligation and selective infusion of Indocyanine Green (ICG) into the inferior mesenteric artery (IMA), and the second after the ligation of both inferior mesenteric artery and vein (IMV) and systemic intravenous infusion of ICG. Fluorescence was detected in real time by means of an infrared imaging system.Results: Sharp resection margins were defined after intra-arterial infusion, and all the tissues in the IMA basin were colored in the first case. In the second model every organ and tissue was colored except the rectum, urinary bladder and ductus deferens.Conclusions: Although systemic intra-venous application of ICG and negative-staining of the rectum including the mesorectum is much easier compared to laparoscopic inter-arterial perfusion through IMA, image results of selevtive IMA-perfusion appear in sharper discrimination of the several layers. Further investigation should focus on simplifying this technique.

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.

Transanal Versus Laparoscopic Total Mesorectal Excision: A Comparative Prospective Clinical Trial from Two Centers

Purpose: Laparoscopic total mesorectal excision (LapTME) faced many obstacles in obese male with narrow pelvis and bulky mesorectum with increased risk of incomplete mesorectal excision and positive circumferential resection margin (CRM) and distal resection margin (DRM). Transanal total mesorectal excision (TaTME) is reported to result in a better quality total mesorectal excision (TME) specimen, lower incidence of CRM and DRM involvement, and higher rates of sphincter preservation. To date, there is still a debate about the feasibility and efficacy of transanal versus the laparoscopic approach for TME in middle and low rectal cancer. Materials and Methods: This is a prospective controlled clinical trial where 38 patients of middle or low rectal cancer from two tertiary centers were nonrandomly assigned to either TaTME or LapTME. Results: Eighteen patients were operated by TaTME versus 20 patients by LapTME. Mean body mass index was significantly higher in the TaTME group (30.74 ± 7.79) than in the LapTME group (25.99 ± 4.68) (P = .03). TaTME was associated with more transanal specimen extraction (55.5% versus 20%, P = .06). No significant differences were detected in CRM, DRM, peri- or postoperative complications, or conversion rates with more reported Clavien-Dindo grade III complications in the TaTME group (P = .29). Conclusions: TaTME facilitated rectal cancer surgery in obese patients and increased the chance of transanal specimen extraction with equivalent oncological outcomes to conventional LapTME. Further studies are recommended to build better evidence.

Robotic Colorectal Surgery

The role of robotics in colon and rectal surgery has been established as an important and effective tool for the surgeon. Its inherent technologies have provided for increased visualization and ease of dissection in the minimally invasive approach to surgery. The value of the robot is apparent in the more challenging aspects of colon and rectal procedures, including the intracorporeal anastomosis for right colectomies and the low pelvic dissection for benign and malignant diseases.

Laparoscopic Versus Open Resection for Rectal Cancer: A Noninferiority Meta-analysis of Quality of Surgical Resection Outcomes

OBJECTIVE

To determine whether laparoscopic surgery is noninferior to open surgery for rectal cancer in terms of quality of surgical resection outcomes.

BACKGROUND

Randomized clinical trials (RCTs) have evaluated the oncologic safety of laparoscopic versus open surgery for rectal cancer with conflicting results. Prior meta-analyses comparing these operative approaches in terms of quality of surgical resection aimed to demonstrate if one approach was superior. However, this method is not appropriate and potentially misleading when noninferiority RCTs are included.

METHODS

MEDLINE, EMBASE, and Cochrane were searched to identify RCTs comparing these operative approaches. Risk differences (RDs) were pooled using random-effects meta-analyses. One-sided Z tests were used to determine noninferiority. Noninferiority margins (ΔNI) for circumferential resection margin (CRM), plane of mesorectal excision (PME), distal resection margin (DRM), and a composite outcome ("successful resection") were based on the consensus of 58 worldwide experts.

RESULTS

Fourteen RCTs were included. Laparoscopic resection was noninferior compared with open resection for the rate of positive CRM [RD 0.79%, 90% confidence interval (CI) -0.46 to 2.04, ΔNI = 2.33%, PNI = 0.026], incomplete PME (RD 1.16%, 90% CI -0.27 to 2.59, ΔNI = 2.85%, PNI = 0.025), and positive DRM (RD 0.15%, 90% CI -0.58 to 0.87, ΔNI = 1.28%, PNI = 0.005). For the rate of "successful resection" (RD 6.16%, 90% CI 2.30-10.02), the comparison was inconclusive when using the ΔNI generated by experts (ΔNI = 2.71%, PNI = 0.07), although no consensus was achieved for this ΔNI.

CONCLUSIONS

Laparoscopy was noninferior to open surgery for rectal cancer in terms of individual quality of surgical resection outcomes. These findings are concordant with RCTs demonstrating noninferiority for long-term oncologic outcomes between the 2 approaches.

Does conversion during laparoscopic rectal oncological surgery increases postoperative complications and anastomotic leakage rates? A meta-analysis

OBJECTIVE

To evaluate, regarding previous published studies, postoperative outcomes between patients undergoing rectal cancer resection performed by totally laparoscopic approach (LAP) compared to those who underwent peroperative conversion (CONV).

METHODS

Studies comparing LAP versus CONV for rectal cancer published until December 2017 were selected and submitted to a systematic review and meta-analysis. Articles were searched in Medline and Cochrane Trials Register Database. Meta-analysis was performed with Review Manager 5.0.

RESULTS

Twelve prospective and retrospective studies with a total of 4503 patients who underwent fully laparoscopic approach for rectal cancer and a total of 612 patients who underwent conversion were included. Meta-analysis did not show any significant difference on overall mortality between both approaches (OR=0.47, 95%CI=0.18-1.22, P=0.12). However, Meta-analysis showed that anastomotic leakage rate, wound abscess rate and postoperative morbidity rate were significantly decreased with totally laparoscopic approach (OR=0.37, 95%CI =0.24-0.58, P<0.0001; OR=0.29, 95%CI=0.19-0.45, P<0.00001; OR=0.56, 95%CI=0.46-0.67, P<0.00001 respectively).

CONCLUSION

This meta-analysis suggests that conversion increases anastomotic leakage, overall morbidity and wound abscess rates without increasing mortality rate for patients who underwent rectal resection for cancer.

Reconsideration of the Safety of Laparoscopic Rectal Surgery for Cancer

The oncological outcomes of laparoscopic rectal cancer surgery were evaluated in recent multicenter randomized clinical trials (RCTs). The MRC-CLASSIC, COLOR II, and COREAN trials found no differences in local recurrence or diseasefree survival rate between laparoscopic and open surgery. However, the noninferiority of laparoscopic surgery with respect to open surgery for rectal cancer was not established on statistical analysis in the ACOSOG Z6051 and the ALaCaRT trials. Quality of total mesorectal excision (TME) is one of the most important prognostic factors. Incomplete TME had unfavorable oncologic outcomes compared to complete TME. Although TME quality can be clearly identified on pathologic evaluation, there is controversy regarding the acceptable range of oncologically safe TME for laparoscopic surgery. It is not certain whether near-complete TME has an unfavorable oncologic impact and whether laparoscopic surgery with near-complete TME is an oncological threat. Therefore, the surgical community will be interested in the long-term outcomes and meta-analyses of ongoing large-scale RCTs. Laparoscopic rectal cancer surgery has been steadily improving its safety for oncology surgery, which has been reported consistently in various multicenter RCTs. To improve surgical quality, colorectal surgeons should choose the most appropriate surgical technique, including laparoscopic surgery.

Laparoscopic surgery for rectal cancer reveals comparable oncological outcome even in context of worse short-term results-long-term analysis of nearly 500 patients from two high-volume centers

PURPOSE

Large randomized controlled trials have investigated the oncological value of the laparoscopic approach to colorectal cancer. Mainly, non-inferiority for the laparoscopic approach regarding long-term survival could be shown. Nevertheless, some recent trials revealed inferiority especially due to histopathological quality of specimen or location of the tumor in the rectum. The main objective of this study was to compare two historical patient collectives of specialized centers for either the laparoscopic or the open resection approach, regarding long-term survival and disease progression of rectal cancer according to tumor localization in a retrospective propensity score-matched analysis.

METHODS

A retrospective analysis, based on two prospectively maintained institutional colorectal cancer databases, was performed. The database of the reference center in Erlangen maintained almost exclusively open operations whereas the database in Lübeck maintained to a vast majority laparoscopic operations. To adjust risk profiles, a 1:1 propensity score matching was performed.

RESULTS

Seven hundred fifty-five patients of both centers (Erlangen, n = 507, Lübeck n = 248) were included. Propensity score matching resulted in two equalized groups with 248 patients. Regarding the postoperative complications, advantages for the open approach were seen. Analyzing the survival data, no differences in disease-free as well as overall survival were shown. Also, no differences in the overall loco-regional recurrence and distant metastasis rate were detected.

CONCLUSION

In centers with adequate expertise, open and laparoscopic procedures result in equivalent oncologic long-term outcomes. Advantages for the open resected group concerning short-term results and complications were detected, due to remarkably low rates of anastomotic leakage.

Surgical techniques in the management of rectal cancer: a modified Delphi method by colorectal surgeons in Australia and New Zealand

BACKGROUND

Technological developments have allowed advances in minimally invasive techniques for total mesorectal excision such as laparoscopy, robotics, and transanal surgery. There remains an ongoing debate about the safety, benefits, and appropriate clinical scenarios for which each technique is employed. The aim of this study was to provide a panel of expert opinion on the role of each surgical technique currently available in the management of rectal cancer using a modified Delphi method.

METHODS

Surveys were designed to explore the key patient- and tumor-related factors including clinical scenarios for determining a surgeon's choice of surgical technique.

RESULTS

Open surgery was favoured in obese patients with an extra-peritoneal tumor and a positive circumferential resection margin (CRM) or T4 tumor when a restorative resection was planned. Laparoscopy was favoured in non-obese males and females, in both intra- and extra-peritoneal tumors with a clear CRM. Robotic surgery was most commonly offered to obese patients when the CRM was clear and if an abdominoperineal resection was planned. Transanal total mesorectal excision (taTME) was preferred in male patients with a mid or low rectal cancer, particularly when obese. Transanal endoscopic microsurgery/transanal minimally invasive surgery local excision was only offered to frail patients with small, early stage tumors.

CONCLUSIONS

All surgical techniques for rectal cancer dissection have a role and may be considered appropriate. Some techniques have advantages over others in certain clinical situations, and the best outcomes may be achieved by considering all options before applying an individualised approach to each clinical situation.

MRI-Based Use of Neoadjuvant Chemoradiotherapy in Rectal Carcinoma: Surgical Quality and Histopathological Outcome of the OCUM Trial

BACKGROUND

Preoperative magnetic resonance imaging (MRI) allows highly reliable imaging of the mesorectal fascia (mrMRF) and its relationship to the tumor. The prospective multicenter observational study OCUM uses these findings to indicate neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

METHODS

nCRT was indicated in patients with positive mrMRF (≤ 1 mm) in cT4 and cT3 carcinomas of the lower rectal third.

RESULTS

A total of 527 patients (60.2%) underwent primary total mesorectal excision, and 348 patients (39.8%) underwent long-term nCRT followed by surgery. The mrMRF was involved in 4.6% of the primary surgery group and 80.7% of the nCRT group. Rates of resections within the mesorectal plane (90.8%), sparing of pelvic nerves on both sides (97.8%), and number of regional lymph nodes (95.3% with ≥ 12 lymph nodes examined) are indicative of high-quality surgery. Resection was classified as R0 in 98.3%, the pathological circumferential resection margin (pCRM) was negative in 95.1%. Patients in the nCRT group had more advanced carcinomas with a significantly higher rate of abdominoperineal excision. Independent risk factors for pCRM positivity were advanced stage (T4), metastatic lymph nodes, resection in the muscularis propria plane, and location in the lower third.

CONCLUSIONS

The risk classification of rectal cancer patients by MRI seems to be highly reliable and allows the restriction of nCRT to approximately half of the patients with clinical stage II and III rectal carcinoma, provided there is a high-quality MRI diagnostic protocol, high-quality surgery, and standardized examination of the resected specimen.

Meta-analysis of the effect of extending the interval after long-course chemoradiotherapy before surgery in locally advanced rectal cancer

BACKGROUND

The current standard of care in locally advanced rectal cancer (LARC) is neoadjuvant long-course chemoradiotherapy (nCRT) followed by total mesorectal excision (TME). Surgery is conventionally performed approximately 6-8 weeks after nCRT. This study aimed to determine the effect on outcomes of extending this interval.

METHODS

A systematic search was performed for studies reporting oncological results that compared the classical interval (less than 8 weeks) from the end of nCRT to TME with a minimum 8-week interval in patients with LARC. The primary endpoint was the rate of pathological complete response (pCR). Secondary endpoints were recurrence-free survival, local recurrence and distant metastasis rates, R0 resection rates, completeness of TME, margin positivity, sphincter preservation, stoma formation, anastomotic leak and other complications. A meta-analysis was performed using the Mantel-Haenszel method.

RESULTS

Twenty-six publications, including four RCTs, with 25 445 patients were identified. A minimum 8-week interval was associated with increased odds of pCR (odds ratio (OR) 1·41, 95 per cent c.i. 1·30 to 1·52; P < 0·001) and tumour downstaging (OR 1·18, 1·05 to 1·32; P = 0·004). R0 resection rates, TME completeness, lymph node yield, sphincter preservation, stoma formation and complication rates were similar between the two groups. The increased rate of pCR translated to reduced distant metastasis (OR 0·71, 0·54 to 0·93; P = 0·01) and overall recurrence (OR 0·76, 0·58 to 0·98; P = 0·04), but not local recurrence (OR 0·83, 0·49 to 1·42; P = 0·50).

CONCLUSION

A minimum 8-week interval from the end of nCRT to TME increases pCR and downstaging rates, and improves recurrence-free survival without compromising surgical morbidity.

Completeness of total mesorectum excision of laparoscopic versus robotic surgery: a review with a meta-analysis

BACKGROUND

TME has revolutionized the surgical management of rectal cancer, and since the introduction of robotic TME (RTME), many reports have shown the feasibility and the safety of this approach. However, concerns persist regarding the advantages of robotic in surgery for the completeness of TME. The aim of this review is to compare robotic versus laparoscopic total mesorectal excision (TME) in rectal cancer, focusing on the completeness of TME.

METHODS

A systematic search was performed in the electronic databases for all available studies comparing RTME versus conventional laparoscopic LTME with declared grade of mesorectum excision. Data regarding sample size, clinical and demographic characteristics, number of complete, nearly complete, and incomplete TME were extracted. Primary outcome was the number of complete TME in robotic and laparoscopic procedures. Secondary outcomes were the numbers of nearly complete and incomplete TME in robotic and laparoscopic rectal resections.

RESULTS

Twelve articles were included in the final analysis. Complete TME was reported by all authors, involving 1510 procedures, showing a significant difference in favor of robotic surgery (OR = 1.83, 95% CI 1.08-3.10, p = 0.03). Nearly complete and incomplete TME showed no significant difference between the procedures. Meta-regression analysis showed that none of patients' and tumors' characteristics significantly impacted on complete TME.

CONCLUSIONS

Our results underline that the robotic approach to rectal resection is the better way to obtain a complete TME. However, it is mandatory that randomized clinical trials should be performed to assess definitively if robotic minimally invasive surgery is better than a laparoscopic resection.

A propensity-score-matched analysis of laparoscopic vs open surgery for rectal cancer in a population-based study

AIM

The oncological risk/benefit trade-off for laparoscopy in rectal cancer is controversial. Our aim was to compare laparoscopic vs open surgery for resection of rectal cancer, using unselected data from the public healthcare system of Catalonia (Spain).

METHODS

This was a multicentre retrospective cohort study of all patients who had surgery with curative intent for primary rectal cancer at Catalonian public hospitals from 2011 to 2012. We obtained follow-up data for up to 5 years. To minimize the differences between the two groups, we performed propensity score matching on baseline patient characteristics. We used multivariate Cox proportional hazards regression analyses to assess locoregional relapse at 2 years and death at 2 and 5 years.

RESULTS

Of 1513 patients with Stage I-III rectal cancer, 933 (61.7%) had laparoscopy (conversion rate 13.2%). After applying our propensity score matching strategy (2:1), 842 laparoscopy patients were matched to 517 open surgery patients. Multivariate Cox analysis of death at 2 years [hazard ratio (HR) 0.65, 95% CI 0.48, 0.87; P = 0.004] and 5 years (HR 0.61, 95% CI 0.5, 0.75; P < 0.001) and of local relapse at 2 years (HR 0.44, 95% CI 0.27, 0.72; P = 0.001) showed laparoscopy to be an independent protective factor compared with open surgery.

CONCLUSIONS

Laparoscopy results in lower locoregional relapse and long-term mortality in rectal cancer in unselected patients with all-risk groups included. Studies using long-term follow-up of cohorts and unselected data can provide information on clinically relevant outcomes to supplement randomized controlled trials.

Systemic review and network meta-analysis comparing minimal surgical techniques for rectal cancer: quality of total mesorectum excision, pathological, surgical, and oncological outcomes

BACKGROUND

Minimal invasive surgery has revolutionized recovery in rectal cancer patients. However, there has been debate on its effect on quality of total mesorectal excision (TME) and oncological outcomes. This network meta-analysis compares laparoscopic, robotic-assisted, and transanal TMEs. This study shows that All three surgical techniques are comparable across TME quality and oncological outcomes. Ultimately, good outcomes are based on each individual surgeon choosing an approach based on their expertise.

Comparison of Short-Term Clinical and Pathological Outcomes after Transanal versus Laparoscopic Total Mesorectal Excision for Low Anterior Rectal Resection Due to Rectal Cancer: A Systematic Review with Meta-Analysis

Background: Transanal total mesorectal excision (TaTME) is a new technique that is designed to overcome the limits of the open and laparoscopic approach for rectal resections. Objective: This study is designed to compare TaTME with standard laparoscopic TME (LaTME). Methods: We searched Medline, Embase, and Scopus databases covering a up to October 2018. Inclusion criteria for study enrolment: (1) study comparing laparoscopic resection of rectal cancer vs. TaTME for rectal malignancy, (2) reporting of overall morbidity, operative time, or major complications. Results: Eleven non-randomized studies were eligible with a total of 778 patients. We found statistical significant differences in regard to major complications in favour of TaTME (RR = 0.55; 95% CI 0.31–0.97; p = 0.04). We did not found significant differences regarding overall complications intraoperative adverse effects, operative time, anastomotic leakage, intra-abdominal abscess occurrence, Surgical Site Infection, reoperations, Length of stay, completeness of mesorectal excision, R0 resection rate, number of harvested lymph nodes, circumferential resection margin, and distal resection margin. Conclusions: This meta-analysis shows benefits of TaTME technique regarding major postoperative complications. Regarding clinicopathological features transanal approach is not superior to LaTME. Currently, the quality of the evidence on benefits of TaTME is low due to lack of randomized controlled trials, which needs to be taken into consideration in further evaluation of the technique. Further evaluation of TaTME require conducting large randomized control trials.

Transanal total mesorectal excision for low rectal cancer: a case-matched study comparing TaTME versus standard laparoscopic TME

Background

Transanal total mesorectal excision (TaTME) is emerging as a novel alternative to laparoscopic total mesorectal excision (LaTME). The aim of this study was to compare clinical and pathological results from these two techniques in patients undergoing rectal resections because of low rectal cancer.

Materials and methods

Thirty-five patients undergoing TaTME were matched with 35 patients operated on using LaTME. Composite primary endpoint (complete TME, negative circumferential resection margin [pCRM], and distal resection margin [pDRM]) was used to assess pathological quality specimens. Secondary outcomes included operative and postoperative parameters (operative time, total blood loss, postoperative morbidity, length of stay, 30-day mortality).

Results

Composite primary endpoint was achieved by 85% of subjects in the TaTME group and 82% of subjects in the LaTME group (P=0.66). Mean pCRM was 1.1±1.29 vs 0.99±0.78 mm (P=0.25). Distal pDRM was 1.57±0.92 and 1.98±1.22 cm (P=0.15). In the TaTME and LaTME groups, respectively, complete mesorectal excision was achieved in 89% and 83% of subjects, while excision was nearly complete for the remaining 11% and 17% (P=0.23).

Conclusion

TaTME appears to be a noninferior alternative to laparoscopic surgery. TaTME allows for quality retrieval of surgical specimens with comparable clinical outcomes with LaTME.

Surgical resection for rectal cancer. Is laparoscopic surgery as successful as open approach? A systematic review with meta-analysis

BACKGROUND

Recently, it has been questioned if minimally invasive surgery for rectal cancer was surgically successful. We decided to perform a meta-analysis to determine if minimally invasive surgery is adequate to obtain a complete resection for curable rectal cancer.

METHODS

A systematic search pertaining to evaluation between laparoscopic and open rectal resection for rectal cancer was performed until 30th November 2016 in the electronic databases (PubMed, Web of Science, Scopus, EMBASE), using the following search terms in all possible combinations: rectal cancer, laparoscopy, minimally invasive and open surgery. Outcomes analyzed were number of clear Distal Resection Margins (DRM or DM), complete Circumferential Resection Margins (CRM) and complete, nearly complete and incomplete Total Mesorectal Excision (TME) and of patients who received laparoscopic or open treatment for rectal cancer.

RESULTS

12 articles were included in the final analysis. The prevalence of successful surgical resection was similar between open and laparoscopic surgery. About distance from distal margin of the specimen, clear CRM and complete TME there were no statistically significant difference between the two groups (MD = -0.090 cm, p = 0.364, 95% CI -0.283, 0.104; OR = 1.032, p = 0.821, 95% CI 0.784, 1.360; OR = 0.933, p = 0.720, 95% CI 0.638, 1.364, respectively). The analysis of nearly complete TME showed a significant difference between the two groups (OR = 1.407, p = 0.006, 95% CI 1.103, 1.795), while the analysis of incomplete TME showed a non-significant difference (OR = 1.010, p = 0.964, 95% CI 0.664, 1.534).

CONCLUSIONS

By pooling together data from 5 RCTs and 7 nRCTs, we are able to provide evidence of safety and efficacy of minimally invasive surgery. Waiting for further randomized clinical trials, our results are encouraging to introduce laparoscopic rectal resection in daily practice.

The Pattern of Defects in Mesorectal Specimens: Is There a Difference between Transanal and Laparoscopic Approaches?

BACKGROUND:

Total mesorectal excision has evolved from open to minimally invasive techniques. To overcome difficulties in the lowest part of the pelvis, transanal total mesorectal excision was introduced and has gained acceptance in the recent years. The results of transanal total mesorectal excision seem to be comparable to laparoscopic total mesorectal excision. Whether or not transanal total mesorectal excision has changed the pattern of defects in the retrieved mesorectal specimens is yet to be clarified.

PURPOSE:

To determine the pattern of mesorectal defects following transanal total mesorectal excision, compared to laparoscopic total mesorectal excision. The primary end-point was the location of defects in the part of the mesorectum below the peritoneal reflection, as it is this part, which is dissected from below in the transanal total mesorectal excision procedure.

METHODS:

From our transanal total mesorectal excision database that includes all transanal total mesorectal excision procedures performed at our institution since 2013, we have included 29 patients who originally had defects in their retrieved specimens. Another 29 patients who underwent laparoscopic total mesorectal excision with mesorectal defects served as a control group. All specimen photos and pathology reports were reviewed systematically; sites and pattern of defects were defined.

RESULTS:

A higher ratio of the defects in the laparoscopic total mesorectal excision group was located below the peritoneal reflection (P = 0.043). The distribution of defects by anatomical quadrant was not statistically different between the groups.

CONCLUSIONS:

The ratio of defects below the peritoneal reflection was lower in the transanal total mesorectal excision group. Whether this is due to a lower incidence of defect in transanal total mesorectal excision is not part of our study.