Predicting postoperative complications after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: retrospective cohort study.

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is an effective but potentially highly morbid treatment option for peritoneal surface malignancies. Adequate risk assessment is fundamental for clinical decision-making and informed patient consent. The aim of this study was to construct a validated nomogram predicting the risk of severe postoperative complications based exclusively on preoperative variables.

METHODS

A prospective database of patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in a single institution between February 1995 and April 2023 was reviewed. The cohort was divided randomly into derivation and validation cohorts (70 : 30). The primary outcome measure was postoperative complications (National Cancer Institute Common Terminology Criteria for Adverse Events grade ≥ 3). Binary logistic regression identified preoperative variables significantly associated with postoperative morbidity. A nomogram was constructed based on the results of the multivariable analysis. The model's performance was evaluated on the validation cohort by receiver operating characteristic curve analysis.

RESULTS

A total of 1039 patients were analysed. The majority of the patients were female (58.8%) and the median age was 56 (interquartile range 46-64) years. The postoperative complication rate was 37.7%, and the reoperation rate 12.7%. A nomogram was constructed based on the following predictive factors: age, body mass index, high-grade histology, disease identified in the left upper quadrant and surrounding the stomach and small bowel mesentery on preoperative imaging, preoperative white blood cell count, and Onodera nutritional index score. Receiver operating characteristic curve analysis showed an area under the curve of 0.707 with accurate calibration curves.

CONCLUSION

Preoperative variables were selected and included in a simple nomogram predicting the risk of postoperative complications. This nomogram could aid clinicians in decision-making and patients in making informed decisions.