Risk Factors for Conversion to Open Surgery in Laparoscopic Nephrectomy for Xanthogranulomatous Pyelonephritis: A Multicenter Study.

Introduction and Objective: Xanthogranulomatous pyelonephritis (XGP) is an infrequent, but life-threatening, chronic granulomatous pyelonephritis. Surgical intervention can be challenging because of severe inflammation and often a fibrotic reaction that obliterates anatomical landmarks. In addition, a high rate of open conversion has been reported when performing a laparoscopic nephrectomy. The aim of this study is to determine the risk factors for open conversion in patients with histologically confirmed XGP who underwent laparoscopic nephrectomy. Methods: A multicenter retrospective study was performed, including patients who underwent laparoscopic nephrectomy between 2018 and 2022 with histopathologic diagnosis of XGP. Clinical and laboratory parameters at initial presentation were evaluated. Extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of laparoscopic nephrectomy and perioperative outcomes were obtained. The primary outcome was conversion to open surgery. Secondary outcomes included major complications, evaluated by Clavien-Dindo ≥3, and organ injuries during the procedure. Results: A total of 49 patients from 5 centers were included, with a mean age of 46.5 ± 17.7 years. Conversion to open surgery was reported in 10 cases (20.4%). Major complications were reported in 13 cases (26.5%), and organ injuries were reported in 10 patients (20.4%). Colonic (3 cases, 6.1%) and pleura injuries (3 cases, 6.1%) were the most frequently affected organ. The presence of renal abscess (odds ratio [OR]: 3.174, p = 0.003) and paranephric extension of disease (Malek stage 3) (OR: 14, p = 0.016) were independent factors related to conversion to open surgery. Conclusion: Laparoscopic nephrectomy for XGP is a technically challenging procedure because of extensive chronic inflammation and fibrosis. The presence of renal abscess and Malek stage III are independent predictors of conversion to open. Despite these challenges, laparoscopic nephrectomy remains a viable and effective approach for managing XGP, with the potential for reduced recovery time and postoperative morbidity compared with open surgery.