The feasibility of laparoscopic rectal resection in patients undergoing reoperation after transanal endoscopic microsurgery (TEM)

Background: The success of transanal endoscopic microsurgery (TEM) for early rectal cancer depends on proper indications and strict patient selection. When unfavorable pathologic features are identified after TEM operation, total mesorectal excision is recommended to minimize the risk of recurrence. In this study, data were collected in a retrospective series of patients to determine the results of laparoscopic reoperation after TEM.

Methods: All patients underwent an accurate rectal-digital examination and clinical tumor staging by transanal endosonography, CT, and/or MRI. The histologic examination included an evaluation of the free margins, depth of tumor infiltration according to International Union Against Cancer guidelines, degree of tumor differentiation, and the presence of lymphovascular and perineural invasion. When a high-risk tumor was identified, reoperation was performed within 6 weeks from TEM. The patients were divided into two groups according to the procedure performed: laparoscopic anterior resection (LAR) or laparoscopic abdominal perineal amputation (LAPR).

Results: Sixty-eight patients (5.3%) underwent reoperation: 38 underwent LAR and 30 underwent LAPR. The mean operative time was 148.24 min (± 35.8, p = 0.62). Meanwhile, the mean distance of the TEM scar from the anal verge differed statistically between the two groups (p = 0.003) and was statistically correlated with abdominal perineal amputation (p = 0.0001) in multivariate analysis. Conversion to open surgery was required in 6 patients (15.7%) in the LAR group and 3 patients (10%) in the LAPR group (p = 0.38). The histologic examination revealed residual cancer cells in 3 cases (3 pT2N0) and 1 case (1 pT3N0), respectively, and lymph node metastases in 4 cases. No residual neoplasms were detected in the remaining 60 cases (88.3%). After a mean follow-up of 108 months, the overall disease-free survival was 98% (95% CI 88-99%).

Conclusions: In our experience, reoperation after TEM using a laparoscopic approach is feasible and safe, with low conversion rates and optimal postoperative results.