A retrospective analysis of 11-year experience in semi-abdominal en bloc evisceration in locally advanced retroperitoneal sarcoma

Background: Extended resection makes it possible to perform a curative resection of conventionally unresectable RPS. However, the rationale and standard procedure for extended resection in RPS remain largely unknown. This study aims to evaluate the efficacy and safety of extended resection using the vascular priority central approach in patients with locally advanced RPS via Semi-Abdominal En Bloc Evisceration (SAEBE). Materials and Methods: We retrospectively enrolled consecutive RPS patients who underwent SAEBE at our centre between March 2010 and August 2021. We then compared the oncological results with those of patients undergoing non-SAEBE using propensity score matching (PSM) analysis. Results: We developed a detailed procedure for SAEBE surgery, incorporating a central approach with vascular priority, and created a series of matched videos. Histological organ invasion (HOI) was observed in 80.1% (109/136) of cases, and postoperative complications occurred in 55.9% (76/136) of patients. Meanwhile, the 3D model identified HOI risk stratification within the different anatomical regions of the RPS. The RPS was found to be particularly prone to invasion in the front and core cord directions, especially in the colon and kidney. The 30-day mortality rate was 2.9% (four out of 136 patients). Following PSM analysis, SAEBE demonstrated comparable rates of severe postoperative complications and mortality to Non-SAEBE. Furthermore, patients with HOI who underwent SAEBE exhibited a strong trend towards improved overall survival (OS) compared to Non-SAEBE (P = 0.042, HR = 0.617, 95% CI: 0.378-1.000). The 1-, 3- and 5-year OS rates were 82.6%, 64.1% and 57% for SAEBE patients and 71.9%, 49.8% and 43.1% for non-SAEBE patients, respectively. Conclusions: Short-term safety outcomes are similar, but patients who underwent SAEBE surgery using the vascular priority central approach showed a trend towards improved long-term survival outcomes compared to those who underwent non-SAEBE surgery. Therefore, SAEBE using the vascular priority central approach may represent a promising treatment option for patients with high-risk HOI of locally advanced RPS.