Bowel Anastomosis After or Before HIPEC: A Comparative Study in Patients Undergoing CRS+HIPEC for Peritoneal Surface Malignancy.

Background: Anastomotic leak after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) remains a dreaded complication. There is no consensus statement regarding the optimal timing for bowel anastomoses to perform after or before HIPEC.

Methods: Patients who underwent CRS+HIPEC and had at least one bowel anastomosis were retrospectively analyzed to evaluate if timing of anastomosis done after or before HIPEC had an impact on bowel complication rates (anastomotic leak and perforation).

Results: From 2013 to 2019, 214 of 370 patients underwent CRS+HIPEC and had at least one bowel anastomosis. Of these 214 patients, 104 and 110 patients had anastomosis after and before HIPEC, respectively. A total of 324 anastomoses were performed, with a mean of 0.87 anastomoses per patient (range 1-4). The incidence of anastomotic leaks was comparable between the pre- and post-HIPEC groups (3.6% vs. 4.8%; p > 0.05), as was the bowel complication rate (7.6% vs. 7.2%). After multivariate analysis, prior surgical score >1 (odds ratio [OR] 4.3), recurrent cancers (OR 7.4), and more than two anastomosis (OR 3.8) were considered independent risk factors for bowel complications.

Conclusion: Anastomosis of the bowel performed after or before HIPEC does not affect bowel complication rates (leak/perforation). Higher prior surgical score, surgery for recurrent cancers, and more than two bowel anastomosis are independent risk factors for predicting bowel complications. Prehabilitation, standardization of steps, immediate attention and repair of serosal tears, and thorough inspection of the bowel before closure helps to decrease bowel complications. The timing of anastomosis can be at the discretion of the surgeon.