Bladder Diverticulectomy
SARAH FRAUMANN FARIS
SAM S. CHANG
Bladder diverticula are the herniation of the bladder mucosa through the detrusor muscle fibers and are classified as either congenital or acquired. Congenital diverticula are postulated to be due to an inadequately developed or thin muscular wall, which is especially vulnerable near the intravesical ureter resulting in a common association with vesicoureteral reflux (1). Bladder diverticula are more common in males, typically present <10 years old and are often solitary and in smoothwalled bladders on cystoscopic examination. In contrast, acquired bladder diverticula are secondary to the elevated intravesical pressures generated as a result of bladder outlet obstruction. The most common causes of outlet obstruction include benign prostatic hyperplasia, urethral stricture disease, bladder neck contracture, posterior urethral valves, and neurogenic voiding dysfunction such as detrusor sphincter dyssynergia. They typically present in males >60 years old and are often multiple and found in association with bladder trabeculation (2).
Diverticula are typically located in the weakest points of the bladder including the ureteral hiatus (paraureteral or
Hutch diverticulum) and both posterolateral walls (1,2,3). The diverticular wall is composed of mucosa, subepithelial connective tissue or lamina propria, occasional muscle fibers, and adventitial tissue, and at times, a fibrous capsule or pseudocapsule may be present (Figs. 21.1 and 21.2) (2,4).
Hutch diverticulum) and both posterolateral walls (1,2,3). The diverticular wall is composed of mucosa, subepithelial connective tissue or lamina propria, occasional muscle fibers, and adventitial tissue, and at times, a fibrous capsule or pseudocapsule may be present (Figs. 21.1 and 21.2) (2,4).
DIAGNOSIS
Acquired bladder diverticula are often asymptomatic and found during the workup for recurrent urinary tract infections, lower urinary tract symptoms, or hematuria. When signs and symptoms are present, they include irritative or obstructive voiding symptoms, pelvic pain or fullness, and hematuria. Urinary stasis often results in recurrent infections that can be difficult to eradicate and may also result in bladder stones. Bladder cancer can also develop in diverticula, and urine cytology should be considered. When evaluating for a bladder diverticula, the differential diagnosis includes urachal, prostatic utricle and müllerian duct cysts, ectopic ureteral insertion, and “pseudodiverticular” images observed in cystograms such as bladder ears, hourglass bladder, everting ureterocele, and vesicular hernias. Other less frequent congenital anomalies should also be considered, such as vesicourachal diverticulum, incomplete bladder duplication, and septation of the bladder (1,5).
Given the nonspecific nature of the presenting symptoms, diverticula are commonly diagnosed on radiographic imaging. Imaging provides important information regarding the number, location, size, and anatomy of the diverticula. A voiding cystourethrogram (VCUG) with lateral, oblique, and postvoid views provides information on the extent of the diverticulum, if there is associated vesicoureteral reflux and the degree of bladder emptying. Additionally, ultrasound, contrast-enhanced computerized tomography (CT) scan and magnetic resonance imaging (MRI) can be useful for the evaluation of associated masses or ureteral obstruction (Fig. 21.3).
A video urodynamics study should be strongly considered to assess bladder anatomy, compliance, and contractility, and identify bladder outlet obstruction and neurogenic voiding dysfunction. It is important that underlying urologic abnormalities are addressed concurrently or prior to definitive surgical treatment of a bladder diverticulum. Prior treatment of the underlying etiology may result in resolution of the initial signs or symptoms, improve bladder emptying, and possibly render further surgical interventions unnecessary (2).
Cystourethroscopy should be performed to exclude urethral stricture disease and bladder neck contracture and rule out occult pathology such as a stone or carcinoma within the diverticulum (6). The entire surface of the diverticulum should be visualized, and the relative location of the ureteral orifices and bladder neck should be noted to assist in planning for any potential surgical procedure. Any suspicious mucosal lesions should be biopsied with extreme care taken to avoid bladder perforation.
INDICATIONS FOR SURGERY
All underlying urologic abnormalities should be addressed concomitantly or prior to definitive surgical treatment of a bladder diverticulum to prevent recurrence. Patients who have improved bladder emptying and symptomatology after relief of outlet obstruction can be managed expectantly with surveillance. In patients who have significantly impaired bladder contractility on preoperative urodynamics, persistently poor bladder emptying after relief of obstruction, or who are unable or unwilling to undergo surgical treatment of the bladder diverticulum, clean intermittent catheterization (CIC) or an indwelling catheter can be effective treatment options (2). In these patients, and in the absence of future complicating factors, surveillance of the bladder diverticulum with cystoscopy and urine cytology, and monitoring of the upper tracts with renal ultrasound and renal function, may be all that is required.
FIGURE 21.3 Contrast-enhanced CT scan demonstrating a large posteriorly based bladder diverticulum seen on (A) transverse and (B) sagittal images. |
Indications for surgical intervention include chronic infections, stones, persistent symptoms, upper urinary tract deterioration from vesicoureteral reflux or obstruction, diverticular rupture, and malignancy (2). Additionally, we recommend simultaneous resection of all poorly emptying bladder diverticula to improve voiding if a patient is scheduled for an open prostatectomy, cystolithotomy, ureteroneocystostomy, or YV plasty of the bladder neck.