Treatment-Related Mortality After Cytoreductive Surgery and HIPEC in Patients with Colorectal Peritoneal Carcinomatosis is Underestimated by Conventional Parameters.

Background: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) as treatment for patients with colorectal peritoneal carcinomatosis (PC) is regarded as an extensive procedure. The risk of postoperative mortality after major abdominal surgery might be substantially higher than described by the 30-day mortality. This study aims to identify causes of 1-year mortality, thereby assessing a more accurate treatment-related mortality rate after CRS + HIPEC.

Methods: All subsequent patients with colorectal PC treated with CRS + HIPEC with complete macroscopic cytoreduction in two tertiary hospitals between April 2005 and April 2013 were included in this study. Causes of 1-year mortality were carefully analyzed and patient data were compared between patients who died or did not die within 12 months after CRS + HIPEC.

Results: Of the 245 included patients, 34 (13.9 %) died within 12 months after CRS + HIPEC. The overall treatment-related mortality rate was 4.9 % (n = 12), and the 30-day and in-hospital mortality rates were 1.6 % (n = 4) and 2.4 % (n = 6), respectively. Furthermore, 18 patients (7.3 %) died due to early recurrent disease. Three patients (1.2 %) died of cardiovascular events, unrelated to CRS + HIPEC. The 1-year mortality group had more extensive peritoneal disease (p = 0.02) and the operative time in this group was longer (p < 0.001).

Conclusions: Overall treatment-related mortality was considerably higher than described by the 30-day and in-hospital mortality rate. However, even though complete macroscopic cytoreduction was achieved in every patient, the main cause of 1-year mortality was early recurrent disease. Both findings are valuable in preoperative patient selection, as well as in preoperative counseling of patients undergoing a CRS + HIPEC procedure.