High incidence of late anastomosis leakage in patients for rectal cancer after neoadjuvant chemoradiotherapy: A comparative study

The purpose of this study was to investigate the clinical features and risk factors of late anastomotic leakage (AL) in a homogeneous cohort with elective sphincter-sparing surgery (SSS) with ileostomy after neoadjuvant chemoradiotherapy (nCRT) for rectal cancer. Data from a total of 359 patients who underwent elective rectal cancer surgery between Jan 2017 and May 2020 were retrospectively reviewed. Patients were classified into early and late AL groups, referring to onset of AL occurring within or after 30 post-operative days, respectively. We analyzed clinical, pathological, and inflammatory features of both AL and risk factors of stoma reversal failure and late AL. A total of 85 patients with SSS with ileostomy after nCRT were classified into 8 (9.4%) patients of early AL and 16 (18.8%) of late AL. Unlike early AL patients, late AL group showed lower neutrophil-lymphocyte ratio (NLR) (P < 0.001) and did not need an invasive intervention at the time of diagnosis. 50% (5/10) patients needed reformation of ileostomy. (P = 0.048) Failure of stoma reversal is associated with advanced stages, high NLR ratio (≥3), and inflammatory lesions seen around anastomosis in radiologic findings, which was confirmed as the risk factor of late AL. Late AL, with different clinical features, showed a higher incidence than early AL in patients who underwent surgery after nCRT and also had a higher stoma reformation rate. Careful evaluation using laboratory and radiological findings before an ileostomy closure is performed to prevent late AL.