Salvage TME following TEM: a possible indication for TaTME

Oncologic safety and technical feasibility of completion transanal total mesorectal excision after local excision; a cohort study from the International TaTME Registry

BACKGROUND

As part of an organ sparing strategy, a surgical local excision may be performed in patients with early-stage rectal cancer or following neoadjuvant (chemo)radiotherapy. In selected cases, a completion total mesorectal excision may be recommended which can be more complex because of the preceding local excision. A transanal approach to perform completion total mesorectal excision may offer an advantage through the better visualization of the surgical field in the distal rectum and less forceful retraction for exposure. However, the oncologic safety and technical feasibility of this approach have yet to be demonstrated in these patients. Therefore, the aim of this study was to evaluate the oncological and technical safety of completion transanal total mesorectal excision following a local excision in patients with rectal cancer.

METHODS

Patients from the prospective International Transanal Total Mesorectal Excision Registry who underwent a surgical local excision prior to completion transanal total mesorectal excision were retrospectively analyzed.

RESULTS

In total, 189 patients were included of which 22% received neoadjuvant radiotherapy. In 94% of the patients, a low anterior resection was performed. A primary anastomosis was constructed in 91% (n = 171/189) of the patients, with the majority also receiving a defunctioning stoma (84%, n = 144/171), of which 69% (n = 100/144) were reversed. Within 30 days, 7% developed an anastomotic leakage. The two-year local recurrence rate was 5% (n = 5/104) with an estimated rate of 3% (95% CI 0-7%). Two-year disease-free survival was 85% (n = 88/104) and overall survival was 95% (n = 99/104).

CONCLUSIONS

Transanal completion total mesorectal excision following local excision for rectal cancer is oncologically safe, with low complication rates and high restorative rates.

Completion Total Mesorectal Excision: A Case-Matched Comparison With Primary Resection

Objectives

The aim of this study was to compare the perioperative and oncological results of completion total mesorectal excision (cTME) versus primary total mesorectal excision (pTME).

Background

Early-stage rectal cancer can be treated by local excision alone, which is associated with less surgical morbidity and improved functional outcomes compared with radical surgery. When high-risk histological features are present, cTME is indicated, with possible worse clinical and oncological outcomes compared to pTME.

Methods

This retrospective cohort study included all patients that underwent TME surgery for rectal cancer performed in 11 centers in the Netherlands between 2015 and 2017. After case-matching, we compared cTME with pTME. The primary outcome was major postoperative morbidity. Secondary outcomes included the rate of restorative procedures and 3-year oncological outcomes.

Results

In total 1069 patients were included, of which 35 underwent cTME. After matching (1:2 ratio), 29 cTME and 58 pTME were analyzed. No differences were found for major morbidity (27.6% vs 19.0%; P = 0.28) and abdominoperineal excision rate (31.0% vs 32.8%; P = 0.85) between cTME and pTME, respectively. Local recurrence (3.4% vs 8.6%; P = 0.43), systemic recurrence (3.4% vs 12.1%; P = 0.25), overall survival (93.1% vs 94.8%; P = 0.71), and disease-free survival (89.7% vs 81.0%; P = 0.43) were comparable between cTME and pTME.

Conclusions

cTME is not associated with higher major morbidity, whereas the abdominoperineal excision rate and 3-year oncological outcomes are similar compared to pTME. Local excision as a diagnostic tool followed by completion surgery for early rectal cancer does not compromise outcomes and should still be considered as the treatment of early-stage rectal cancer.

Completion Total Mesorectal Excision After Transanal Local Excision of Early Rectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Completion total mesorectal excision is recommended when local excision of early rectal cancers demonstrates high-risk histopathological features. Concerns regarding the quality of completion resections and the impact on oncological safety remain unanswered.

OBJECTIVE

This study aims to summarize and analyze the outcomes associated with completion surgery and undertake a comparative analysis with primary rectal resections.

DATA SOURCES

Data sources included PubMed, Cochrane library, MEDLINE, and Embase databases up to April 2021.

STUDY SELECTION

All studies reporting any outcome of completion surgery after transanal local excision of an early rectal cancer were selected. Case reports, studies of benign lesions, and studies using flexible endoscopic techniques were not included.

INTERVENTION

The intervention was completion total mesorectal excision after transanal local excision of early rectal cancers.

MAIN OUTCOME MEASURES

Primary outcome measures included histopathological and long-term oncological outcomes of completion total mesorectal excision. Secondary outcome measures included short-term perioperative outcomes.

RESULTS

Twenty-three studies including 646 patients met the eligibility criteria, and 8 studies were included in the meta-analyses. Patients undergoing completion surgery have longer operative times (standardized mean difference, 0.49; 95% CI, 0.23-0.75; p = 0.0002) and higher intraoperative blood loss (standardized mean difference, 0.25; 95% CI, 0.01-0.5; p = 0.04) compared with primary resections, but perioperative morbidity is comparable (risk ratio, 1.26; 95% CI, 0.98-1.62; p = 0.08). Completion surgery is associated with higher rates of incomplete mesorectal specimens (risk ratio, 3.06; 95% CI, 1.41-6.62; p = 0.005) and lower lymph node yields (standardized mean difference, -0.26; 95% CI, -0.47 to 0.06; p = 0.01). Comparative analysis on long-term outcomes is limited, but no evidence of inferior recurrence or survival rates is found.

LIMITATIONS

Only small retrospective cohort and case-control studies are published on this topic, with considerable heterogeneity limiting the effectiveness of meta-analysis.

CONCLUSIONS

This review provides the strongest evidence to date that completion surgery is associated with an inferior histopathological grade of the mesorectum and finds insufficient long-term results to satisfy concerns regarding oncological safety. International collaborative research is required to demonstrate noninferiority.

REGISTRATION NO

CRD42021245101.

The role of transanal total mesorectal excision

At inception, transanal total mesorectal excision (TaTME) was hypothesized to be a solution for several problems encountered in pelvic surgery, particularly for distal rectal cancer. The transanal part of the procedure is less hampered by patient related factors such as visceral obesity and a narrow bony pelvis and can thus overcome access and visualization problems encountered with a pure abdominal approach. Clearly, as for any new technique, a learning curve needs to be negotiated, ideally without unacceptable harm to patients. Once in experienced hands, TaTME might overcome challenges found in anatomically challenging rectal cancer patients as well as for other indications. The role of TaTME is not to replace, but rather complement its abdominal counterpart.

Early salvage total mesorectal excision (sTME) after organ preservation failure in rectal cancer does not worsen postoperative outcomes compared to primary TME: systematic review and meta-analysis

IMPORTANCE

While oncological outcomes of early salvage total mesorectal excision (sTME) after local excision (LE) have been well studied, the impact of LE before TME on postoperative outcomes remains unclear. We aimed to compare early sTME with a primary TME for rectal cancer.

METHODS

Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines with the random-effects model were adopted using Review Manager Version 5.3 for pooled estimates.

RESULTS

We retrieved eleven relevant articles including 1728 patients (350 patients in the sTME group and 1438 patients in the TME group). There was no significant difference between the two groups in terms of mortality (OR = 0.90, 95%CI [0.21 to 3.77], p = 0.88), morbidity (OR = 1.19, 95%CI [0.59 to 2.38], p = 0.63), conversion to open surgery (OR = 1.34, 95%CI [0.61 to 2.94], p = 0.47), anastomotic leak (OR = 1.38, 95%CI [0.50 to 3.83], p = 0.53), hospital stay (MD = 0.23 day, 95%CI [- 1.63 to 2.10], p < 0.81), diverting stoma rate (OR = 0.69, 95%CI [0.44 to 1.09], p = 0.11), abdominoperineal resection rate (OR = 1.47, 95%CI [0.91 to 2.37], p = 0.11), local recurrence (OR = 0.94, 95%CI [0.44 to 2.04], p = 0.88), and distant recurrence (OR = 0.88, 95%CI [0.52 to 1.48], p = 0.62). sTME was associated with significantly longer operative time (MD = 25.62 min, 95%CI[11.92 to 39.32], p < 0.001) lower number of harvested lymph nodes (MD =  - 2.25 lymph node, 95%CI [- 3.86 to - 0.65], p = 0.006), and higher proportion of incomplete TME (OR = 0.25, 95%CI [0.11 to 0.61], p = 0.002).

CONCLUSIONS

sTME is not associated with increased postoperative morbidity, mortality, or local recurrence. However, the operative times are longer and yield a poor specimen quality.

Completion total mesorectal excision following transanal endoscopic microsurgery does not compromise outcomes in patients with rectal cancer

BACKGROUND

Transanal endoscopic microsurgery (TEM) represents a choice of treatment in patients with neoplastic lesions in the rectum. When TEM fails, completion total mesorectal excision (cTME) is often required. However, a concern is whether cTME increases the rate of abdominoperineal resections (APR) and is associated with higher risk of incomplete mesorectal fascia (MRF) resection. The aim of this study was to compare outcomes of cTME with primary TME (pTME) in patients with rectal cancer.

METHODS

This was a nationwide study on all patients with cTME from the Danish Colorectal Cancer Group database between 2005 and 2015. Patients with cTME were compared to patients with pTME after propensity score matching (matching ratio 1:2). Matching variables were age, gender, tumor distance from anal verge, American Society of Anesthesiologists (ASA) score and American Joint Committee on Cancer (AJCC) stage.

RESULTS

A total of 60 patients with cTME were compared with 120 patients with pTME. Patients with cTME experienced more intraoperative complications as compared to pTME patients (18.3% vs. 6.7%, p = 0.021). However, there was no difference in the rate of perforations at or near the tumor/previous TEM site (6.7% vs. 2.5%, p = 0.224), conversion to open surgery (p = 0.733) or 30-day morbidity (p = 0.86). On multivariate analysis, cTME was not a risk factor for APR (OR 2.49; 95% CI 0.95-6.56; p = 0.064) or incomplete MRF (OR 1.32; 95% CI 0.48-3.63; p = 0.596). There was no difference in the rate of local recurrence between cTME and pTME (5.2% vs. 4.3%, p = 0.1), distant metastases (6.8% vs. 6.8%, p = 1), or survival (p = 0.081). The mean follow-up time was 6 years.

CONCLUSION

In our study, the largest so far on the subject, we find no difference in postoperative short- or long-term outcomes between cTME and pTME.

Association of Transanal Total Mesorectal Excision With Local Recurrence of Rectal Cancer

IMPORTANCE

Proponents of novel transanal total mesorectal excision (TME) suggest the procedure overcomes the technical and oncologic challenges of conventional approaches for treating rectal cancer. Recently, however, there has been controversy regarding the oncologic safety of the procedure.

OBJECTIVE

To assess the association of transanal TME with the incidence of local recurrence (LR) of cancer and the probability of remaining free of LR during follow-up.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study used data from 8 high-volume rectal cancer academic institutions from across Canada on all consecutive patients with primary rectal cancer treated by transanal TME at the participating centers. The study was conducted between January 2014 and December 2018, and data were analyzed from April 1, 2020, to September 15, 2020.

EXPOSURE

Transanal TME.

MAIN OUTCOMES AND MEASURES

The incidence of LR was reported as a direct measure of quality of resection. The cumulative probability of LR- and systemic recurrence (SR)-free survival at 36 months was estimated. Local recurrence and SR were defined as radiologic or endoscopic evidence of 1 or more new lesions in or outside the pelvis, respectively, documented during surveillance after the removal of the primary tumor.

RESULTS

Of 608 total patients included in the analysis, 423 (69.6%) were male; the median age was 63 years (interquartile range [IQR], 54-70 years). Local recurrence was identified in 22 patients (3.6%) after a median follow-up of 27 months (IQR, 18-38 months). The median time to LR was 13 months (IQR, 9-19 months). Sixteen of the 22 patients with LR (72.7%) were male, 14 (63.6%) received neoadjuvant chemoradiation, and 12 (54.5%) had American Joint Committee on Cancer stage III disease. Of those with LR, 16 (72.7%) had a negative circumferential radial margin and 20 (90.9%) had a negative distal resection margin, 2 (9.1%) experienced conversion to open surgery, and 15 (68.2%) also developed SR. The probability of LR-free survival at 36 months was 96% (95% CI, 94%-98%). According to the Cox proportional hazards regression model, the hazard ratio of LR was estimated to be 4.2 (95% CI, 2.9-6.2) times higher among patients with a positive circumferential radial margin than among those with a negative circumferential radial margin.

CONCLUSIONS AND RELEVANCE

In this cohort study, transanal TME performed by experienced surgeons was associated with an incidence of LR and SR that is in line with the published literature on open and laparoscopic TME, suggesting that transanal TME may be an acceptable approach for management of rectal cancer.

The utility of preoperative radiological evaluation of early rectal neoplasia: a systematic review and meta-analysis

AIM

The diagnostic role for preoperative imaging of clinically benign rectal adenomas is unclear. The objective of this systematic review and meta-analysis was to examine the diagnostic accuracy of preoperative imaging in distinguishing benign adenomas from rectal cancer.

METHOD

A systematic search was performed for all studies published that correlated staging of clinically benign rectal adenomas with endorectal ultrasound (ERUS) or MRI and histology. Imaging was compared with postoperative histology and data on the numbers of true positives, false positives, true negatives and false negatives were extracted. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random effects model. The QUADAS2 tool was used to determine the methodological quality of included studies.

RESULTS

Eleven studies describing 1511 patients were retrieved. A total of 1134 patients underwent local excision and 377 had a formal proctectomy. A benign rectal adenoma was diagnosed in 840 and 214 had a T1 rectal cancer. For confirming benign adenomas, the pooled sensitivity of ERUS was 0.81 (95% CI 0.69-0.89) and specificity was 0.85 (95% CI 0.68-0.93). For detecting occult T1 tumours, the pooled sensitivity of ERUS was 0.50 (95% CI 0.33-0.66) and specificity was 0.89 (95% CI 0.82-0.94). Quantitative analysis of MRI could not be performed due to insufficient studies.

CONCLUSION

This study demonstrates the limited accuracy of preoperative ERUS in distinguishing benign adenomas from T1 rectal cancer. Preoperative imaging must be interpreted with caution to prevent over-staging and unnecessary proctectomy. We propose that clinically benign lesions may undergo local excision, with subsequent management based on final histology.

Outcomes of completion total mesorectal excision are not compromised by prior transanal minimally invasive surgery

AIM

Transanal minimally invasive surgery (TAMIS) is used increasingly often as an organ-preserving treatment for early rectal cancer. If final pathology reveals unfavourable histological prognostic features, completion total mesorectal excision (cTME) is recommended. This study is the first to investigate the results of cTME after TAMIS.

METHOD

Data were retrieved from the prospective database of the Elisabeth-TweeSteden Hospital. Completion TME patients were case matched with a control group of patients undergoing primary TME (pTME). Primary and secondary outcomes were surgical outcomes and oncological outcomes, respectively.

RESULTS

From 2011 to 2017, 20 patients underwent cTME and were compared with 40 patients undergoing pTME. There were no significant differences in operating time (238 min vs 226 min, P = 0.53), blood loss (137 ml vs. 158 ml, P = 0.88) or complications (45% vs 55%, P = 0.07) between both groups. There was no 90-day mortality in the cTME group. The mesorectal fascia was incomplete in three patients (15%) in the cTME group compared with no breaches in the pTME group (P = 0.083). There were no local recurrences in either group. In three patients (15%), distant metastases were detected after cTME compared with one patient (2.5%) in the pTME group (P = 0.069). After cTME patients had a 1- and 5-year disease-free survival of 85% compared with 97.5% for the pTME group (P = 0.062).

CONCLUSION

Completion TME surgery after TAMIS is not associated with increased peri- or postoperative morbidity or mortality compared with pTME surgery. After cTME surgery patients have a similar disease-free and overall survival when compared with patients undergoing pTME.

Local excision followed by early radical surgery in rectal cancer: long-term outcome

Background

In rectal cancers, radical surgery should follow local excisions, in cases of unexpected, unfavorable tumor characteristics. The oncological results of this completion surgery are inconsistent.

This retrospective cohort study assessed the clinical and long-term oncological outcomes of patients that underwent completion surgery to clarify whether a local excision compromised the results of radical surgery.

Methods

Forty-six patients were included, and the reasons for completion surgery, intraoperative complications, residual tumors, local recurrences (LRs), distant metastases, and cancer-specific survival (CSS) were assessed. The results were compared to 583 patients that underwent primary surgery without adjuvant therapy, treated with a curative intention during the same time period.

Results

The median follow-up was 14.6 years. The reasons for undergoing completion surgery were positive resection margins (24%), high-risk cancer (30%), or both (46%). Intraoperative perforations occurred in 10/46 (22%) cases. Residual tumor in the rectal wall or lymph node involvement occurred in 12/46 (26%) cases. The risk of intraoperative perforation and residual tumor increased with the pT category. Intraoperative perforations did not increase postoperative complications, but they increased the risk of LRs in cases of intramural residual tumors (p = 0.003). LRs occurred in 2.6% of pT1/2 and 29% of pT3 tumors. Both the 5- and 10-year CSS rates were 88.8% (95% CI 80.0–98.6). Moreover, the LRs of patients with pT1/2 cancers were lower in patients with completion surgery than in patients with primary surgery.

Conclusions

Rectal wall perforations at the local excision site and residual cancer were the main risks for poor oncological outcomes associated with completion surgery. Local excisions followed by early radical surgery did not appear to compromise outcomes compared to patients with primary surgery for pT1/2 rectal cancer. Improvements in clinical staging should allow more appropriate selection of patients that are eligible for a local excision of rectal cancer.