Clinical features and surgical strategy of retroperitoneal liposarcoma involving the kidney capsule: a retrospective comparative cohort study

Abstract

Background: Valid and generalizable data on the clinical features and surgical strategies for retroperitoneal liposarcoma (LPS) involving the kidney capsule remain scarce. This study aimed to investigate the clinical characteristics, morbidity, mortality, and long-term survival of patients with retroperitoneal LPS involving the kidney capsule. Methods: The authors analyzed a prospectively maintained database of patients who underwent surgical resection for retroperitoneal LPS between 2015 and 2020. The patients were categorized into kidney capsule or no kidney capsule groups based on the presence or absence of kidney capsule involvement. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule was developed. The primary outcome measure was overall survival (OS). The cumulative event probability curve was estimated using the Kaplan–Meier, and differences between groups using the Log-Rank. Results: The study population consisted of 128 patients—54 with and 74 without kidney capsule involvement. Of these patients, 70 were female (54.7%) and 58 were male (45.3%), with a median age of 55. The median follow-up duration was 35 months. Postoperative morbidity, mortality, length of hospital stay, length of ICU stay, OS, and recurrence-free survival (RFS) did not differ significantly between the groups. Eleven patients developed postoperative acute kidney injury (AKI), and one patient required dialysis during the follow-up period. In multivariable logistic regression analysis, only nephrectomy was independently associated with postoperative AKI. Subgroup analysis of patients with kidney capsule involvement showed that nephrectomy did not improve OS or RFS but significantly decreased postoperative estimated glomerular filtration rate. Conclusion: Nephrectomy was associated with an increased risk of postoperative AKI after retroperitoneal LPS resection. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule achieved optimal clinical outcomes.