Neoadjuvant concurrent chemoradiotherapy followed by transanal total mesorectal excision assisted by single-port laparoscopic surgery for low-lying rectal adenocarcinoma: a single center study.

Purpose: To assess the feasibility and short-term outcomes of neoadjuvant chemoradiotherapy (CCRT) followed by transanal total mesorectal excision assisted by single-port laparoscopic surgery (TaTME-SPLS) for low-lying rectal adenocarcinoma.

Methods And Materials: A total of 23 patients with clinical stage II-III low-lying (from anal verge 0-8 cm) rectal adenocarcinoma who underwent neoadjuvant CCRT followed by TaTME-SPLS consecutively from December 2015 to December 2018, were enrolled into our study. Chi-squared testing and Student's t testing were used to make parametric comparisons, and Fisher's exact test or the Mann-Whitney U test were used to make nonparametric comparisons.

Results: Conversion rate in patients who underwent neoadjuvant CCRT followed by TaTME-SPLS was only 4%. The mean operation time was 366 min and the inter-sphincter resection (ISR) was done for 14 patients (60%). The mean number of lymph nodes harvested was 15. There was no surgical mortality, but the 30-day morbidity rate was 21% (5 patients were Clavien-Dindo I-II). Pathological complete response was 21.74% with 100% organ preservation and 100% clear distal margin after neoadjuvant CCRT followed by TaTME-SPLS.

Conclusion: TaTME-SPLS would be highly successful in lymph node negative and low T stage of low-lying rectal cancer patients who had pathological complete remission or high percentage of partial remission after neoadjuvant CCRT.