Inpatient outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in the United States, 2018–2023.

Abstract

e15605 Background: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is a highly complex oncologic procedure historically concentrated at academic referral centers but increasingly performed in community settings. Contemporary national benchmarks describing inpatient outcomes and variation by hospital structural characteristics remain limited, limiting population-level insight into access, safety, and organization of CRS/HIPEC care. Methods: A retrospective, serial cross-sectional analysis was performed using the 2018–2023 Healthcare Cost and Utilization Project National Inpatient Sample. Adult hospitalizations with peritoneal carcinomatosis or primary peritoneal malignancy were identified using ICD-10-CM codes. CRS/HIPEC was ascertained using ICD-10-PCS procedure proxies for major gastrointestinal excision or resection with intraperitoneal chemotherapy. Outcomes included in-hospital mortality (primary), length of stay, and hospitalization cost estimated using cost-to-charge ratios. National estimates accounted for survey weighting and stratification. Secondary analyses evaluated outcomes by hospital teaching status and bed size. Survey-weighted regression models adjusted for demographics, payer, neighborhood income quartile, elective admission status, APR-DRG severity and risk of mortality, and calendar year. Results: In-hospital mortality following CRS/HIPEC demonstrated graded variation by hospital structural characteristics, instead of binary separation between academic and non-academic centers. Mortality was lowest at urban teaching hospitals (6.77%), modestly higher at urban non-teaching hospitals (8.25%), and substantially higher at rural hospitals (14.49%). A similar gradient was observed by bed size, with lower mortality at large hospitals (6.44%) compared with medium (8.36%) and small (8.72%) hospitals, indicating that the largest mortality differentials were in lower-resource settings. From 2018–2023, an estimated 58,320 CRS/HIPEC hospitalizations were identified nationally, increasing from 9,005 in 2018 to 10,655 in 2023, reflecting continued national adoption of CRS/HIPEC. Overall in-hospital mortality was 7.02% (95% CI, 6.50–7.58), with a mean length of stay of 13.08 days (95% CI, 12.75–13.40). Among hospitalizations with available cost-to-charge ratio data, mean hospitalization cost was $55,189. Conclusions: In this national inpatient analysis, CRS/HIPEC was associated with substantial mortality, prolonged length of stay, and high costs, with outcomes varying by hospital structural characteristics. The graded risk pattern suggests that resource context and rescue capacity may be more influential than academic designation alone.