Abstract

Purpose: Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and surrounding tissues seen mostly in diabetic patients. Diagnosis and adequate therapeutic regimen are controversial. We reviewed the clinical presentation, diagnosis and aspects of surgical management of patients presenting with severe EPN.

Patients and methods: Patients with EPN managed in our unit between 1996 and 2004 were reviewed. Diagnosis was confirmed by CT scan appearance of gas in the renal or perirenal area in a very ill patient. We compared the outcome of immediate nephrectomy with drainage of perinephric abscesses in patients presenting with severe EPN.

Results: Seven patients were managed in our unit during the 8-year period. All patients were diabetic and women outnumbered men (6:1). Renogram in all 7 patients showed renal function of affected kidney to be less than 15% in 6 patients. Escherichia coli was isolated in all patients from either urine, blood or perinephric pus. Management consisted of intensive resuscitation, control of blood glucose and use of intravenous antibiotics. Emergency nephrectomy was performed in 3 patients, delayed nephrectomy after an initial period of percutaneous drainage in 2 patients, incision and drainage in one patient and immediate percutaneous drainage was performed in one patient. One patient died 5 days post-nephrectomy of myocardial infarction. Patients who had immediate nephrectomy recovered quicker (18-21 days) and had no postoperative complications. Patients who had incision and drainage, or percutaneous drainage presented with recurrent discharging sinuses or perinephric abscesses requiring further surgical interventions and spent longer time in hospital (28-37 days).

Conclusion: Patients with severe EPN often present in extremis and require intensive medical treatment. The diagnosis must be entertained in diabetic women presenting with flank pain and septicemia. The function of the affected kidney is often very poor and early nephrectomy offers the best outcome. Percutaneous drainage or incision and drainage of the abscess may be performed in patients too ill for immediate formal nephrectomy.