PURPOSE: To determine the risk factors associated with major complications in patients with histologically confirmed Xanthogranulomatous pyelonephritis (XGP) who underwent nephrectomy.

METHODS: A multicenter retrospective study was performed including patients who underwent nephrectomy between 2018 and 2022 with histopathological diagnosis of XGP. Clinical and laboratory parameters at the initial presentation were evaluated. Data on extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of nephrectomy and perioperative outcomes were obtained. The primary outcome was major complications, defined as a CD ≥ grade 3 and the need for intensive care unit (ICU) admission. Secondary outcomes included the comparison of complications evaluating the nephrectomy approach (transperitoneal, retroperitoneal, and laparoscopic). A sub-analysis stratifying patients who needed ICU admission and Malek classification was performed.

RESULTS: A total of 403 patients from 10 centers were included. Major complications were reported in 98 cases (24.3%), and organ injuries were reported in 58 patients (14.4%), being vascular injuries the most frequent (6.2%). Mortality was reported in 5 cases (1.2%). A quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥ 2, increased creatinine, paranephric extension of disease (Malek stage 3), a positive urine culture, and retroperitoneal approach were independent factors associated with major complications.

CONCLUSION: Counseling patients on factors associated with higher surgical complications is quintessential when managing this disease. Clinical-radiological staging, such as the Malek classification may predict the risk of major complications in patients with XGP who will undergo nephrectomy. A transperitoneal open approach may be the next best option when laparoscopic approach is not feasible.