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Bladder Diverticulum: Etiology, Diagnosis and Treatment

Definition

The bladder diverticulum is an outpouching of the bladder wall (Powell et al., 2009). In pseudodiverticula, only the mucous membrane of the bladder herniates; the diverticulum wall is without a muscle layer. In true diverticula, the outpouching consists of all bladder wall layers.

Ultrasound imaging of a small bladder diverticulum.

Etiology

Congenital diverticula:

Congenital diverticula are caused by a weakness of the urinary bladder wall, particularly often in the area of the orifice (Hutch diverticulum). They are often associated with vesicoureteral reflux and the ureter may drain into the diverticulum. Diverticula may be caused by abnormalities of the urachus at the bladder dome. Congenital bladder diverticula are sometimes true diverticula with herniation of all wall layers.

Acquired diverticula:

Acquired diverticula are caused by chronically increased pressure during voiding, which leads to the herniation of the bladder mucosa through weak gaps of the muscular layer (pseudodiverticula). A pseudocapsule forms around the diverticulum wall, which is helpful in resecting the diverticulum. The narrow, sphincter-like diverticulum neck increases the urinary stasis in the diverticulum.

• BPH: men over 50
• Neurogenic lower urinary tract dysfunction, especially with detrusor-sphincter-dyssynergia.
• Urethral valves: affects boys.
• Iatrogenic: after insufficient bladder suturing.

Sign and Symptoms

LUTS (also due to the underlying disease), recurrent urinary tract infections, bladder stone formation.

Diagnosis

Urine:

Urine culture and treat possible infection before therapy.

Ultrasound imaging:

Diverticula can be best identified with a full bladder [fig. US imaging of sall bladder diverticulum and US of a large diverticulum]. The kidney is examined to exclude hydronephrosis or to identify a duplex kidney.

Ultrasound imaging of a large diverticulum caused by BPH (sagittal plane (left) and transverse plane (right): the diverticulum is larger than the bladder (HB) with prominent bladder wall thickness and a narrow neck of the diverticulum. With kind permission, Dr. med. C. Hornig, Augsburg.

VCUG:

Cystography is done with several projections (lateral and a.p.) for exact documentation of size and location [fig. Cystography of a bladder diverticulum]. The residual volume of the diverticulum after voiding is a factor for treatment decisions.

Cystography of a bladder diverticulum prior to surgical therapy: a catheter was inserted into the diverticulum and blocked with 50 ml. A DJ was inserted to mark the orifice and ureter. The ureter and bladder are displaced to the right by the left diverticulum.

Postoperative specimen of a large bladder diverticulum, see also cystography above and section "bladder diverticulectomy" for laparoscopic findings of the same patient.

Cystoscopy:

Cystoscopy focuses on the bladder and diverticulum mucosa for suspicious lesions, which should be biopsied (Cave: thin diverticulum wall). Assess the diverticulum size, anatomical relationship between the diverticulum neck and the ureter, and prostatic urethra for subvesical obstruction.

Cystoscopic findings of BPH, bladder diverticulum and trabeculated bladder wall.

Cystoscopic findings bladder diverticulum with bladder carcinoma. With kind permission, Dr. J. Schönebeck, Ljungby, Schweden.

Imaging of the upper urinary tract:

Ultrasound imaging is sufficient; if there are abnormalities, intravenous urography, retrograde pyelography, or CT may be necessary.

Urodynamics:

Urodynamic studies are sometimes necessary for the diagnosis of unclear micturition disorders.

Treatment of Bladder Diverticulum

Conservative therapy:

Significant bladder diverticula with subvesical obstruction of high-risk surgical patients may be managed with permanent catheterization or, if possible, intermittent self-catheterization.

Endoscopic therapy:

Bladder diverticula may be treated endoscopically during subvesical desobstruction: resection of the narrow diverticulum neck to improve communication with the urinary bladder and coagulation of the diverticulum mucosa to induce scarring and shrinkage. Size is the limiting factor for endoscopic therapy, and controlled trials are unavailable (Adachi et al., 1991).

Surgical therapy:

Various surgical techniques for resection of bladder diverticula are possible, see also section bladder diverticulectomy.

• Transvesical diverticulum resection: suitable for the therapy of small bladder diverticula.
• Extravesical diverticulum resection: suitable for treating large bladder diverticula. The technique can be performed with open surgery or laparoscopy, depending on the need for simultaneous desobstruction of the prostate or ureter reimplantation. Inserting a ureteral splint and a transurethral catheter into the diverticulum before surgical therapy simplifies orientation.

References

Adachi, M.; Nakada, T.; Yamaguchi, T.; Suzuki, H.; Hirano, J.; Hirano, K.; Hashimoto, T.; Iijima, Y.; Ishii, N. & Gotoh, Y. Transurethral treatment of bladder diverticula.
Eur. Urol. 1991, 19, 104-108.

Powell, C. R. & Kreder, K. J. Treatment of bladder diverticula, impaired detrusor contractility, and low bladder compliance.
Urol Clin North Am 2009, 36, 511-25.

  Deutsche Version: Diagnose und Therapie von Harnblasendivertikel