Dis Colon Rectum. 2021 Apr 22. doi: 10.1097/DCR.0000000000002110. Online ahead of print.
ABSTRACT
BACKGROUND: A recent Norwegian moratorium challenged the status quo of transanal total mesorectal excision for rectal cancer reporting increased early multifocal local recurrences.
OBJECTIVE: The aim of this systematic review and meta-analysis was to evaluate the local recurrence rates following transanal total mesorectal excision as well as to assess statistical, clinical, and methodological bias in reports published to date.
DATA SOURCES: The Pubmed and MEDLINE (via Ovid) databases were systematically searched.
STUDY SELECTION: Descriptive or comparative studies reporting rates of local recurrence at a median follow-up of 6 months (or more) after transanal total mesorectal excision were included.
INTERVENTIONS: Transanal total mesorectal excision.
MAIN OUTCOME MEASURES: Local recurrence was any recurrence located in the pelvic surgery site. Untransformed proportion method of one-arm meta-analysis was utilized. Untransformed percent proportion with 95% confidence interval was reported. Ad-hoc meta-regression with Omnibus test was utilized to assess risk factors for local recurrence. Among-study heterogeneity was evaluated: statistical by I2 and tau2, clinical by summary tables, and methodological by a 33-item questionnaire.
RESULTS: Twenty-nine studies totaling 2,906 patients were included. The pooled rate of local recurrence was 3.4% (2.7%, 4.0%) at an average of 20.1 months with low statistical heterogeneity (I2=0%). Meta-regression yielded no correlation between complete total mesorectal excision quality (p=0.855), circumferential resection margin (p=0.268), distal margin (p=0.886), and local recurrence rates. Clinical heterogeneity was substantial. Methodological heterogeneity was linked to excitement of novelty, loss aversion, reactivity to criticism, indication for transanal total mesorectal excision, non-probability sampling, circular reasoning, misclassification, inadequate follow-up, reporting bias, conflict-of-interest, and self-licensing.
LIMITATIONS: Included studies had observational design, limited sample and follow-up.
CONCLUSION: This systematic review found a pooled rate of local recurrence of 3.4% at 20 months. However, given the substantial clinical and methodological heterogeneity across the studies, the evidence for or against transanal total mesorectal excision is inconclusive at this time.
PMID:33938532 | DOI:10.1097/DCR.0000000000002110
