Pelvic Peritonectomy Poorly Affects Outcomes in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Metastases.

BACKGROUND

Constraints of pelvic anatomy render complete cytoreduction (CRS) challenging. The aim of this study is to investigate the impact of pelvic peritonectomy during CRS/HIPEC on colorectal peritoneal metastasis (CRPM) patients' outcomes.

METHODS

This is a retrospective analysis of a prospectively maintained CRS/hyperthermic intraperitoneal chemotherapy (HIPEC) database. The analysis included 217 patients with CRPM who had a CRS/HIPEC between 2014 and 2021. We compared perioperative and oncological outcomes of patients with pelvic peritonectomy (PP) (n = 63) to no pelvic peritonectomy (non-PP) (n = 154).

RESULTS

No differences in demographics were identified. The peritoneal cancer index (PCI) was higher in the PP group with a median PCI of 12 vs. 6 in the non-PP group (p < 0.001). Operative time was 4.9 vs. 4.3 h in the PP and non-PP groups, respectively (p = 0.63). Median hospitalization was longer in the PP group at 12 vs. 10 days (p = 0.007), and the rate of complications were higher in the PP group at 57.1% vs. 39.6% (p = 0.018). Pelvic peritonectomy was associated with worse disease-free (DFS) and overall survival (OS) with 3-year DFS and OS of 7.3 and 46.3% in the PP group vs. 28.2 and 87.8% in the non-PP group (p = 0.028, p .> 0.001). The univariate OS analysis identified higher PCI (p = 0.05), longer surgery duration (p = 0.02), and pelvic peritonectomy (p < 0.001) with worse OS. Pelvic peritonectomy remained an independent prognostic variable, irrespective of PCI, on the multivariate analysis (p < 0.001).

CONCLUSIONS

Pelvic peritonectomy at the time of CRS/HIPEC is associated with higher morbidity and worse oncological outcomes. These findings should be taken into consideration in the management of patients with pelvic involvement.