AbstractPyelonephritis is a bacterial infection of the upper urinary tract, with uro-digestive fistulas representing a rare but serious complication. Prompt management guided by imaging is essential to prevent progression to more severe forms.
We report the case of a 40-year-old patient hospitalized for a painful swelling of the left flank associated with persistent fever. Contrast-enhanced abdominal CT revealed left-sided obstructive pyelonephritis caused by a staghorn calculus, complicated by a psoas abscess and a fistulous communication between the upper calyceal group and the left colon. Additional collections in the lumbar and anterolateral soft tissues were also identified.
Initial ultrasound revealed soft tissue collections, while contrast-enhanced CT confirmed the urological origin of the infection and precisely delineated the fistulous tract. Intra-renal air bubbles, multiple calculi, and a calyceal wall defect communicating with the colon were key diagnostic features.
The patient was managed with intravenous antibiotics, surgical drainage of abscesses, and double nephrostomy of the left kidney. The clinical course was favorable, with resolution of symptoms, normalization of laboratory parameters, and most notably, spontaneous obliteration of the uro-digestive fistula confirmed on follow-up imaging.
Although rare, uro-digestive fistulas should be considered in patients with complicated lithiasic pyelonephritis. Imaging-particularly contrast-enhanced CT-is crucial for accurate diagnosis and monitoring. A conservative approach can lead to a favorable outcome when instituted early.
