A rare case of herniated duplex collecting system causing obstructive uropathy

Abstract Background An inguinal hernia is the protrusion of intraabdominal organs through an opening in the abdominal wall. Structures such as small and large intestines are commonly contained within inguinal hernias. However, uretero-inguinal hernia of the native collecting system is an extremely rarely reported entity. If unrecognized, acute kidney injury due to obstructive uropathy or serious intraprocedural ureteral injuries during hernia repair can occur. A duplex collecting system is a congenital kidney anomaly with an incidence of 0.8%. A uretero-inguinal hernia involving duplicated ureters has not been previously described in literature. Here we report a case of obstructive uropathy secondary to uretero-inguinal hernia involving duplicated ureters. Case presentation A 78-year-old male known to have a left sided inguinal hernia presented to the Emergency department with two weeks of intermittent suprapubic tenderness, dysuria, frequency, urgency, frothy urine as well as nausea and vomiting. Workup on admission revealed an elevated creatinine of 2.8 mg/dl. CT imaging revealed duplicated left sided ureters with left inguinal hernia containing the ureters. There was cystic ureteral dilation within the herniation sac as well as moderate left hydroureteronephrosis. Patient had an elective inguinal hernia repair with left ureteral stent placement. Following the surgery, he had recovery of kidney function to the previous baseline serum creatinine of 1.5 mg/dl. Conclusion A duplex collecting system arises when two ureteral buds are formed during fetal development. However, diagnosis can be made in rare instances during adulthood when duplex collecting systems are usually found incidentally. Uretero-inguinal hernias have been reported as a common complication of renal transplant. However, uretero-inguinal hernias in native kidneys are considered an uncommon finding, especially with a duplex collecting system. When patients present with herniation and acute kidney injury, it is important to rule out the possibility of uretero-inguinal hernia to minimize complications such as obstructive uropathy and kidney failure. CT scan providing cross-sectional imaging is the ideal modality for identification of the site and etiology of urinary tract obstruction and site of herniation. If during imaging, an obstructive uropathy is observed, a nephroureteral stent or nephrostomy tube can be inserted to protect the ureter as well as relieve the obstruction, respectively.