Obstructive uropathy due to uretero-inguinal hernia: An uncommon occurrence.

Obstructive uropathy secondary to uretero-inguinal hernia is a rare phenomenon. Two types have been described-the rarer extraperitoneal type is frequently associated with other renal anomalies. Pre-operative diagnosis is essential in order to reduce the risk of ureteric injury intra-operatively. We describe one such case.

CASE

A 67-year-old obese man was referred for further investigation following an episode of sudden - onset left-sided loin pain that had lasted for 6 h and then resolved spontaneously. He had type 2 diabetes mellitus, but no other relevant past medical history. Physical examination revealed a large left - sided irreducible, non-tender inguino-scrotal hernia, and laboratory investigation, including serum creatinine was within normal limits. An ultrasound scan of his renal tract revealed left-sided hydronephrosis, and a subsequent computed tomography scan showed left-sided hydronephrosis with a dilated ureter that was seen to enter the large inguino-scrotal hernia [Figures 1 and 2]. It then took a path back out of the hernia where it became non-dilated and inserted into the bladder in its usual position.

Figure 1

Non-contrast (left) and delayed phase (right) coronal computed tomography scan showing dilated left ureter entering large left inguino-scrotal hernia (arrows)

Figure 2

Venous phase coronal computed tomography showing left ureter after having left the inguino-scrotal hernia as it enters the bladder. Note, how the ureter is now of normal calibre (arrow)

A subsequent dimercaptosuccinic acid (DMSA) scan confirmed reduced function of the affected kidney, contributing 35% to overall renal function and hence he underwent a mesh repair of this hernia with careful dissection of the ureter from the hernial sac and his post-operative recovery was uneventful.

DISCUSSION

Uretero-inguinal hernia in patients with non-transplant kidneys is a rare phenomenon with the majority diagnosed intra-operatively when found unexpectedly during the hernia repair.[1] Two types have been described-paraperitoneal, accounting for 80% of cases, in which the ureter is pulled into the hernia alongside the peritoneal sac due to an adherent layer of posterior peritoneum; and extraperitoneal, in which no peritoneal sac is present in the hernia and the ureter is involved alone or in combination with retroperitoneal fat. In our case, the intra-operative findings confirmed a paraperitoneal type. The rarer extraperitoneal form is more commonly associated with renal tract anomalies (such as renal ptosis),[2] and hence renal tract imaging should be performed even if it is incidentally found at surgery.

As this condition is associated with inguinal herniation, it is more common in men, typically in the fifth or sixth decade. Reported pre-disposing features include obesity and a deficiency in collagen synthesis.[3] Pre-operative diagnosis is important to reduce the significant risk of ureteral injury during surgery.[45] Although stenting of the ureter facilitates identification and protection during the hernia repair, the length and tortuosity of the herniated ureter make endourological procedures (such as ureteric stent insertion) difficult and hence careful dissection of the ureter from the hernial sac and replacement in the retroperitoneal space is imperative to prevent injury.