Nephrectomy for xanthogranulomatous pyelonephritis — a not-so-simple solution

Background: Xanthogranulomatous pyelonephritis (XGP) is a rare chronic inflammatory condition of the kidney, associated with high patient morbidity, often requiring targeted antibiotic therapy and surgical removal of the affected kidney.

Aim: We report the outcomes of patients undergoing nephrectomy for XGP in our institution over a 12-year period.

Methods: Following ethical approval, a retrospective review of histological samples of renal tissue demonstrating features of XGP from June 2010 to 2022 was conducted. Laboratory, imaging, and clinical data of included participants were collected.

Results: Eleven patients were included (8 women, 3 men), mean age of 58.1 (35-81). Recurrent urinary tract infection was the most common clinical presentation (55%, n = 6). Other presentations included flank pain (36%, n = 4), collection/ abscess (45%, n = 5), and nephro-cutaneous fistulae (9%, n = 1). The majority of patients had bacteriuria (91%, n = 10), and Escherichia coli was the most common bacteria isolated (55%, n = 6). Antibiotic resistance was seen in 60% of positive urine samples (n = 6). An open nephrectomy was performed in all but one case (91%, n = 10). A postoperative complication occurred in 73% (n = 8), with 50% (n = 4) of complications Clavien Dindo grade 3 or higher, including one patient mortality.

Conclusions: XGP is a difficult and complex condition to treat. All patients in this series presented with infection or associated sequelae thereof. Complex XGP cases therefore often require open nephrectomy and have high rates of postoperative complications. Careful consideration of antibiotic and operative intervention is therefore essential to ensure the best outcome for these patients.