Unrecognized horseshoe kidney precipitating a severe renal pelvis injury during routine laparoscopic cholecystectomy: a case report

Horseshoe kidney (HSK) is a common congenital fusion anomaly characterized by lower renal positioning, malrotation, and aberrant ventrally displaced collecting systems. Iatrogenic urinary tract trauma during laparoscopic cholecystectomy is exceedingly rare, but distorted retroperitoneal anatomy can predispose patients to inadvertent injury. A 25-year-old female presented on postoperative day 10 following an uneventful laparoscopic cholecystectomy with worsening lower abdominal pain, gross hematuria with blood clots, and an acute hemoglobin drop from 14.0 g/dl to 8.0 g/dl requiring two units of packed red blood cells. Immediate postoperative hematuria had been initially confounded with ongoing menses. Multiphase computed tomography (CT) urography and intraoperative fluoroscopy revealed an unsuspected horseshoe kidney with a grade IV renal injury and active urinary extravasation originating from the right moiety. The patient was managed conservatively with retrograde double-J ureteral stenting, bed rest, and close clinical observation. Hemostasis and resolution of the extravasation were achieved without requiring open or minimally invasive surgical re-exploration. The stent was subsequently removed with complete clinical recovery. Postoperative gross hematuria following routine laparoscopic procedures demands prompt evaluation to exclude retroperitoneal injury. Even high-grade urinary extravasation secondary to congenital fusion anomalies can be managed successfully with timely endoscopic retrograde stenting and conservative monitoring.