Repeat Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Using Open and Closed Abdomen Techniques for Colorectal Peritoneal Metastases and Peritoneal Pseudomyxoma Recurrences: Results from Six French Expert Centers

Background: Standard treatment for resectable peritoneal metastases (PM) combines cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC); however, the rate of recurrence remains high and repeat CRS/HIPEC may be considered in well-selected patients. We describe our postoperative and oncological outcomes.

Methods: Between 1994 and 2024, data from 132 repeat CRS/HIPEC procedures were analyzed in this retrospective multicenter study. Morbimortality, overall survival (OS) and recurrence-free survival (RFS) were evaluated for colorectal peritoneal metastases (CRPM) and peritoneal pseudomyxoma (PMP).

Results: Overall, 63 patients, including 55 patients with CRPM (87.3%) and 8 patients with PMP (12.7%), underwent CRS/HIPEC. Of these patients, 58 (92%) underwent CRS/HIPEC twice, 4 (6.3%) underwent CRS/HIPEC three times, and 1 (1.6%) underwent CRS/HIPEC four times. Peritoneal Carcinomatosis Index (PCI) score, operating room occupancy, complication and readmission rates at day 90, and length of intensive care unit and hospital stay were similar between the initial and first repeat CRS/HIPEC procedures. No 90-day postoperative mortality occurred. For CRPM, the median OS was 82.3, 53.9, and 74.5 months from the initial, first, and second repeat CRS/HIPEC procedures, respectively, with a median RFS of 22.0, 36.9, and 13.2 months, respectively. For PMP, after a median follow-up of 70.8 and 39.3 months from the initial and first repeat CRS/HIPEC procedures, respectively, all patients were alive, with a median RFS of 22.4 and 39.4 months, respectively. Multivariate analysis shown that no factor was significantly related to severe complications (Dindo-Clavien 3-4) or OS.

Conclusions: In selected patients with CRPM and PMP, CRS/HIPEC shows comparable results between the initial and repeat procedures in terms of postoperative outcomes, and appears to improve survival, especially for PMP. Repeat CRS/HIPEC is an option to be considered in patients presenting with CRPM or PMP.