What is bladder diverticulum?

Bladder diverticulum refers to a sac where the bladder mucosa bulges outward after passing through the bladder wall muscle layer. It has both congenital and secondary causes. There are some muscle fibers in the bladder diverticulum. If it is more serious, it may lead to lower urinary tract obstruction, easily cause stones, infection, urinary retention, etc., and even cause diverticulum tumors, which is quite harmful to human health.

Causes

Due to defects in the bladder muscle layer, local outward bulging of the bladder occurs, often at the posterior side of the bladder, often accompanied by the formation of bladder trabeculae and small cells. 1. Congenital lesions such as urethral stenosis, posterior urethral valve, bladder neck contracture, and obstruction promote the formation and development of diverticula and are the main factors for the formation of diverticula. 2. Acquired lower urinary tract obstruction and bladder hypertension (neurogenic bladder) are the main causes of secondary bladder diverticulum.

Clinical manifestations

If there are no complications, bladder diverticulum has no special symptoms. If there is obstruction or infection, symptoms such as difficulty urinating, frequent urination, urgency, and urinary tract infection may occur. Some diverticula can compress the bladder neck and urethra, leading to lower urinary tract obstruction. The lack of muscle contraction in the diverticulum can lead to poor urine drainage, which is easily accompanied by ureterovesical reflux, unilateral or bilateral hydronephrosis, and ultimately lead to renal failure.

There are also cases of congenital giant diverticula without urinary tract obstruction. Because there are very few muscle fibers in the wall of the bladder diverticulum, urine in the giant diverticulum cannot be discharged during urination, and secondary urination symptoms may occur. Some patients have hematuria due to infected stones in the diverticulum. A small number of patients may have urinary retention due to compression of the bladder outlet by the huge diverticulum located behind the bladder neck, which can compress the rectum and cause constipation, and compress the uterus and cause dystocia.

Differential Diagnosis

1. When ureteral diverticulum is complicated by infection, there are also urinary tract irritation symptoms such as frequent urination, urgency, and pain when urinating. When the diverticulum is large, a mass can also be palpated, but B-ultrasound shows that the cystic mass is outside the outline of the bladder. The diverticula at the lower end of the ureter can be demonstrated by ultrasound, CT, MRI combined with excretory or retrograde urography, which can also show the location of the diverticula, and ureteral dilatation can be seen above the diverticula. 2. Urethral diverticulum also has two sections of urination, but cystography and voiding cystourethrography can show that there is no diverticulum in the bladder, but a cystic mass in the urethra. Urethrascopy shows that the diverticulum opens in the urethra rather than in the bladder. 3. Prostatic hyperplasia may also cause segmented urination, and some patients may have pseudodiverticula, but the patients are relatively old, and the symptoms are mainly frequent urination and urgency, especially frequent urination at night. Rectal examination shows that the prostate is enlarged and the central groove is shallow. Ultrasound and CT scans can show that the prostate is enlarged and raised, and the patient's urine flow rate is abnormal. 4. Duplicated bladder Giant bladder diverticulum needs to be differentiated from duplicated bladder. Ultrasound and CT examinations showed that the bladder had a complete muscle layer and mucosa. Transurethral angiography and cystoscopy showed that there were partitions or two complete bladders in the bladder.