Risk of Intraoperative Hyperthermia and Outcomes in Adults Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) is commonly used to treat peritoneal surface malignancies. We aimed to identify risk factors of intraoperative patient hyperthermia and the postoperative outcome of adults undergoing HIPEC Patients and Methods: A retrospective, IRB approved, single center cohort study was conducted. Adults treated with cytoreductive surgery and HIPEC between 2006 and 2021 were included. The primary outcome was bladder hyperthermia during perfusion, stratified by severity and duration. Secondary outcomes were postoperative complications and recurrence-free (RFS) and overall (OS) survival. Multivariable logistic regression models were fit to estimate the effects of important covariates. Results: Out of 214 patients, 114 had mild hyperthermia (≥ 38 °C) at any time, and in 73 of these it lasted for ≥ 30 min. Independent prognostic factors of mild hyperthermia ≥ 30 min were age (OR = 0.958, 95% CI 0.933–0.984), body mas index (BMI; OR = 0.959 95% CI 0.917–1.002), gender (OR = 0.199, 95% CI 0.092–0.431), and type of chemotherapy [cisplatin versus mitomycin (OR = 0.186, 95% CI 0.070–0.491; oxaliplatin versus mitomycin (OR = 0.430, 95% CI 0.163–1.139)]. Prognostic factors of moderate-to-severe hyperthermia (≥ 39 °C) at any time were perfusion duration (OR = 1.094, 95% CI 1.018–1.177) and blood transfusion (OR = 5.689, 95% CI 1.784–18.137). Intraoperative hyperthermia was not associated with increased postoperative complications but was associated with better RFS and OS. Conclusions: Our study demonstrates age, gender, BMI, and chemotherapy type to be associated with hyperthermia ≥ 38 °C for ≥ 30 min, whereas longer perfusion time and blood transfusion were associated with hyperthermia ≥ 39 °C. Mild hyperthermia at the end of perfusion is associated with better RFS and OS.