Xanthogranulomatous pyelonephritis: a systematic review of treatment and mortality in more than 1000 cases

Objectives: To systematically review the current demographics, treatment and mortality rate associated with xanthogranulomatous pyelonephritis (XGP) and to test the hypothesis that the weighted pooled peri-operative mortality rate will be <10%. 

Methods: Searches were performed of the Cochrane, Embase and Medline databases and the grey literature for studies published during the period 1 January 2000 to 30 August 2021. Eligible studies reported cohorts of ≥10 predominantly adult patients with XGP and described either average patient age or mortality rate. 

Results: In total, 40 eligible studies were identified, representing 1139 patients with XGP. There were 18 deaths, with a weighted pooled peri-operative mortality rate of 1436 per 100 000 patients. The mean age was 49 years, 70% of patients were female and 28% had diabetes mellitus. The left kidney was more commonly affected (60%). Four patients had bilateral XGP, and all of whom survived. Renal or ureteric stones were present in 69% of patients, including 48% with staghorn calculi. Urine culture was positive in 59% of cases. Fistulae were present in 8%. Correct preoperative diagnosis occurred in only 45% of patients. Standard treatment continues to comprise a short cause of antibiotics and open radical (total) nephrectomy. Preoperative decompression occurred in 56% of patients. When considered at all, laparoscopic nephrectomy was performed in 34% of patients. Partial nephrectomy was conducted in 2% of patients. 

Conclusions: Xanthogranulomatous pyelonephritis has a lower mortality rate than historically reported. A typical patient is a woman in her fifth or sixth decade of life with urolithiasis. While open radical nephrectomy remains the most common treatment method, laparoscopic, and to a lesser degree partial nephrectomy, are feasible in well selected patients.