diverticula

diverticula

Bladder diverticula can be congenital or acquired (secondary to infravesical bladder outlet obstruction). Acquired bladder diverticula are most commonly seen in adult men with benign - prostatic obstruction; acquired diverticula can less commonly be seen in children with infravesical obstruction (e.g. secondary to posterior urethral valves) or in children with neurogenic bladder associated with detrusor–sphincter dyssynergia (DSD). Primary congenital bladder diverticula develop as a herni - ation of bladder mucosa through a congenital muscular defect between the intravesical ureter and the roof of the ureteral hiatus, the so-called ‘Hutch’ diverticulum. Congenital divertic - ula are therefore typically located in the vicinity of the ureteric orifice and may be associated with vesicoureteric reflux (VUR), both of which are thought to occur as a r esult of inadequate development of the musculature of the bladder wall or Wald - eyer’s fascia around the portion of the intravesical ureter, at - ). - , Berlin, Germany . Waldeyer’s fascia is a layer of fascia that

Allantois Future bladder Urorectal septum Urogenital sinus Cloaca Anorectal canal Figure 83.3 Partitioning of the cloaca to form the urogenital sinus and anorectal canal. (Redrawn with permission from Wein AJ, Kavoussi LR, Partin AW, Peters CA. Campbell-Walsh urology , 11th edn. Phila

delphia, PA: Elsevier, 2016: 2834.)

the embryological junction of the ureteric bud and urogenital sinus. As opposed to acquired diverticula, intravesical pressures in those with congenital diverticula are not elevated and so the bladder is generally thin walled, without trabeculation or mul tiple diverticula. In adults with acquired diverticula, the intra vesical pressures are often elevated, and the bladder is thick walled with trabeculations and multiple diverticula. The raised intravesical pressure causes the lining between the inner layer of hypertrophied muscle to protrude, f orming multiple sac cules. If a saccule is forced through the bladder wall, it becomes a diverticulum. The diverticulum is made up of mucosa with very few , if any , muscle fibre cov erings. As a result, it does not contract to empty and therefore holds residual urine, which can lead to the complications described below ( Figure 83.4 Clinical features Small congenital bladder diverticula are often asymptomatic. Haematuria (due to infection, stone or tumour) is a symptom in about 30%. Common symptoms or complications include: /uni25CF recurrent urinary tract infections (UTIs); /uni25CF bladder stones ( Figure 83.5 ); /uni25CF urinary retention – due to extrinsic compression of the bladder outlet by a large diverticulum; /uni25CF hydronephrosis – due to extrinsic ureteral compression by a large diverticulum; /uni25CF neoplasm ( Figure 83.6 ) – account for 1% of all bladder tumours; the lack of a muscular layer to the diverticulum a ff ects pathological staging of bladder tumours as there is, by definition, no T2 stage. Therefore, any invasion beyond the lamina propria in a bladder diverticular tumour should be staged as T3. - - - ).

Figure 83.4 Cystogram showing a large bladder diverticulum. Figure 83.5 Magnetic resonance imaging scan showing a large left- sided bladder diverticulum containing stones (arrow). Figure 83.6 Computed tomography scan showing a bladder divertic

ulum containing soft-tissue material consistent with tumour (arrow).