Impact of BMI on Perioperative Complications Following CRS and HIPEC for Appendiceal Cancer

Background/Aim: Obesity is considered a risk factor for poorer postoperative outcomes. Its effect in the context of cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is less well understood. This study examined the effect of body mass index (BMI) on postoperative surgical outcomes in patients with appendiceal cancer who underwent CRS/HIPEC. Patients and Methods: A retrospective analysis performed including adult patients with appendiceal cancer who underwent CRS/HIPEC between 2021 to 2023 and grouped into weight ranges based on body mass index (BMI). Intraoperative and postoperative outcomes were recorded. Continuous variables were compared using Kruskal Wallis tests while categorical variables were compared using Chi squared tests. Multivariate regression analysis was performed and models controlled for age, sex and peritoneal cancer index. Results: A total of 130 adult patients who underwent CRS/HIPEC for appendiceal cancer were included in the analysis. Intraoperative outcomes were not significantly different between weight range groups. Wound complication rates were higher among patients with BMI >30 (p=0.014). The mortality rate and rate of complications were not statistically different between BMI groups. In the adjusted model, patients with higher BMI were more likely to develop cardiovascular complications [odds ratio (OR)=1.092, p=0.018] but were less likely to develop obstruction or ileus postoperatively (OR=0.911, p=0.045). Conclusion: Surgery is a key component of the management of peritoneal surface malignancies but patients with higher BMI may be at increased risk of perioperative complications, potentially altering the perioperative management of this patient cohort. However, it is unclear what specific risks obesity confers to morbidity and mortality or oncological outcomes. In our study, when stratified by BMI, there was a significant difference in wound-related complications and increased likelihood of cardiovascular complications in patients with higher BMI who underwent CRS/HIPEC for appendiceal malignancy. There were no other significant differences in intra-operative or morbidity outcomes. These findings would suggest that high BMI should be considered but not prohibit patient selection for operative management. In such patients, BMI and cardiovascular risk profile should be optimised to improve perioperative outcomes.