COLORENAL FISTULA - A Rare Association with Emphysematous Pyelonephritis
SV Mehta, SH Somani, AA Bokil, J Bhawani, M Patil, PJ Chibber
Department of Urology, Sir JJ Hospital, Mumbai.
Emphysematous pyelonephritis presenting as a communication between the renal calyx and the colon is rare. The florid gas found on CT scan, and X-ray KUB can be well explained by this occurrence.
Emphysematous pyelonephritis is a rare infection of the kidney, produced by gas forming organisms. It is commonly seen in diabetics. High glucose levels serve as a substrate for fermentation by gas forming organisms e.g. E Coli.  Impaired host defences caused by local factors such as obstruction and systemic factors such as diabetes, allows organisms with gas forming capability to produce carbon dioxide by fermentation of substrates such as necrotic material. Emphysematous pyelonephritis should be considered as a complication of severe pyelonephritis rather than a separate entity. The overall mortality is 43%.
A 65 year old diabetic female presented with right sided flank pain of 15 days duration associated with fever and chills. She was on irregular antidiabetic medication. On examination, she was found to be febrile with pulse of 120/min. and blood pressure of 90/70. She was in septicaemia. Urine output was 600 ml. over 24 hours. Examination of the right flank revealed a tender lump measuring 15 cm x 15 cm. moving poorly with respiration. The rest of the abdomen was normal. She was resuscitated to normalize her blood pressure. Urine examination revealed plenty of pus cells. Cultures grew E. Coli sensitive to Amikacin. Random blood sugar was 265 mg/ml. and was controlled on plain insulin. Serum creatinine was 2 on admission which later fell to 1.5 on resuscitation. X-ray of the kidneys showed gas shadows confirming to the renal contour. Ultrasonography showed hyper-echoeic shadows in the region of the right kidney, [3,4] suggestive of gas. CT scan of the abdomen showed gas in the parenchyma and collecting system of the right kidney with surrounding soft tissue involvement (Fig. 1).
The patient was explored using a right flank incision. The kidney, perinephric fat and peritoneum were densely adherent. During the course of dissection the kidney was found to be densely adherent to the ascending colon. A fistula was found communicating between the region of the lower pole and the ascending colon (Fig. 2). A right sided nephrectomy with ascending colectomy and ileo-ascending anastomosis was performed. The rest of the abdomen and colon were explored by an anterior extension of the incision, and were normal. She had an uneventful recovery.
Emphysematous pyelonephritis as a cause of renal infection is rare. Extension of the infection to the surrounding retroperitoneum has been reported. However involvement of the surrounding organs like the ascending colon has not been described. A possibility of the colon being the
Fig 1 CT Scan (Gas in the kidney, retroperitoneum.)
primary cause of this pathologic process was ruled out, by finding normal colon distally, and no evidence of malignancy on histology. Patients with this infection must be started on appropriate antimicrobials and treatment of associated diabetes must be initiated. Function of the opposite kidney must be established as the condition is known to be bilateral in 10% of cases.  Surgical treatment must aim at complete removal, as attempts at more conservative treatment have been unsuccessful.  In selected cases associated with obstruction, percutaneous drainage with antimicrobial therapy has been successful in restoring renal function. Due to septicaemia and persistent infection, decision for nephrectomy was taken as an emergency life saving procedure.
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