Splenectomy During Cytoreductive Surgery: Marker of Surgical Burden or Independent Predictor of Morbidity?

Background Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is a cornerstone treatment for peritoneal metastases but carries substantial morbidity. Splenectomy is frequently performed during CRS, yet it remains uncertain whether it independently increases postoperative risk or merely reflects greater surgical complexity. Methods We retrospectively analyzed 124 CRS procedures performed between 2014 and 2023 at a tertiary center, including 20 splenectomy cases. Operative characteristics, morbidity, and mortality were compared between splenectomy and non-splenectomy groups. Propensity score matching (PSM; 1:2 nearest-neighbor) and inverse probability of treatment weighting (IPTW; average treatment effect on the treated) were applied to adjust for baseline imbalances across age, ASA score, PCI, blood loss, primary tumor type, sex, and number of anastomoses. Results Patients undergoing splenectomy exhibited higher PCI scores (median 18.5 vs 9; P < .001), greater blood loss (775 vs 450 mL; P = .037), longer operative times (9 vs 6 hours; P = .007), and more visceral resections (median 4.5 vs 2; P < .001). Severe complications occurred in 60% of splenectomy vs 27% of non-splenectomy cases ( P = .007), while mortality did not differ significantly (15% vs 8.7%; P = .408). After adjustment, splenectomy was not an independent risk factor for morbidity (PSM: OR 2.69, P = .193; IPTW: OR 1.76, P = .37). Higher ASA score, perioperative fluid replacement, and blood loss remained significant predictors. Conclusions Splenectomy during CRS correlates with higher observed morbidity but not with independently increased risk after controlling for surgical complexity. These findings suggest splenectomy reflects procedural burden rather than a direct hazard, underscoring the importance of contextual interpretation and vigilant perioperative management.