Bladder diverticulum

A diverticulum is a pouch which projects through the wall of a hollow organ. In the bladder, a distinction is made between congenital and acquired diverticula.

Congenital bladder diverticula are relatively rare. They often involve a weakness in the area where the ureters join the bladder. This is known as a Hutch diverticulum after the doctor who first described it. This can disrupt the flow of urine from the kidneys and cause urine to flow back into the kidneys when passing water. To prevent long-term damage, in severe cases a Hutch diverticulum will require surgery.

Acquired diverticula are caused by disorders of bladder emptying. If a high pressure is required to empty urine from the bladder, the lining of the bladder can bulge outwards between gaps in the muscle layer, just like on an old car tyre. This is known as a false diverticulum or pseudodiverticulum, because, in contrast to 'true' diverticula, it does not involve all layers of the bladder wall.

They are generally caused by difficulty emptying the bladder as a result of an enlarged prostate, narrowings of the urethra caused by scarring (strictures) or neurological disorders which affect bladder emptying.

Treatment primarily involves treating the cause. Where the diverticulum is particularly large, it will often need to be surgically removed, and the bladder sown back together.