Discussion
Bladder hernia is a rare condition, accounting for 1-3% of inguinal hernia5. Most of bladder heriation occur on the right side and are direct type.1 The pathophysiology of an inguinal bladder herniation was similar with direct type inguinal hernia, as the sheath of peritoneum traverse through the weak point of abdominal fascia5. Some risk factors are associated with this condition, including obesity, weakness of abdominal musculature, chronic urinary obstruction, male gender, old age and benign prostatic hypertrophy5, 6. Most of the patient are typically asymptomatic while some of them may be suffered by lower urinary tract symptoms (LUTS). In advance cases, patient may describe two-stage voiding as they have to complete urination by compressing scrotal-bladder manually7. As occurred in our case, previous reports have shown that some patient might developed bilateral hydronephrosis, acute kidney injury and ureteral obstruction resulting from bladder compression7, 8.
There are several examinations could be used for diagnosing bladder herniation. Besides physically examination, sonography provided another non-invasive, non-radiation method which may demonstrate a hypoechoic mass inside the scrotum. The size of the mass may decrease after voiding or Foley indwelling. Sonography could also be used for screening of hydronephrosis and hydroureter. Voiding cystourethrography may revealed a dog-ear shape of bladder inside the scrotum, providing adequate evidence for diagnosis.1 Computed tomography (CT) scan could provide most detailed information for diagnostic purpose and surgical planning, including whether there is contralateral herniation or other organ herniation simultaneously.
While radiology imaging is not routinely performed in the workup of inguinal hernia, only 7% of inguinal bladder hernias are diagnosed before operation. Furthermore, complication such as bladder injury or bladder leakage may occurred during surgery, accounting for 16-23.5% of all bladder hernia.4, 9 Thus, it is important to identify bladder hernia prior to operation.
The most frequently reported surgical way of treating bladder hernia is open repair, yet our patient underwent a laparoscopic total extraperitoneal approach (TEP) hernia repair. Laparoscopic surgery provides several advantages including improving visibility of bladder and surrounding structures, rapid recover, less pain and improved cosmesis.10 Currently, there were several published literatures reporting laparoscopic repair of herniated bladder, however, in best of our knowledge, non-of them provide intra-operative image clearly.