Almost all patients had other associated congenital anomalies especially orthopedic, neurologic, or other urologic anomalies like renal agenesis, dysplastic or ectopic kidneys, ectopic ureters, bicornuate and absent uterus, or vaginal atresia in females and absent prostate, seminal vesicles, or penis in males. Three cases of bladder agenesis in the VATER association have been reported [3].

Unless the ureters are able to drain to an ectopic location such as the vagina, which occurred in the two oldest surviving patients reported, bladder agenesis is incompatible with life. Bladder agenesis is recorded mainly in males, and the reported survived cases are mostly females (Figs. 6.1 and 6.2) [4].

Complete bladder duplication is further subclassified according to the orientation of the septum intervening between the two bladders into sagittal or coronal, which is the rarest type. The sagittal septum is reported much more common where the two bladders are lying side by side, each receiving the ureter of its ipsilateral kidney and drained by a separate urethra (Fig. 6.4) [10].

Cystoscopy will help to complete the evaluation of both urethras, bladder necks, and ureteral orifices. Surgical management usually includes excision of the bladder septum while both bladders are united together with ligation of one urethra such that the common bladder will be drained by the more functional urethra.

Acquired cases are more common and usually due to voiding dysfunctions and acquired bladder outlet obstruction, and this type will not be discussed herein.

As regard the diverticula in relation to the ureteral orifice, they can be further classified into:

When symptomatic in children, the most common presentation is urinary tract infection. Other presentations are hematuria, stones, and urinary retention [16].

Some cases are associated with additional urologic anomalies (urethral strictures and valves, neurogenic bladder, and duplicated collecting system) or syndromes (e.g., Ehlers–Danlos syndrome, prune-belly syndrome, Menkes syndrome, cutis laxa, and Williams syndrome) [17].

Double micturition and residual urine on catheterization after micturition are additional signs, especially with large diverticula.

Ureteral obstruction is unusual, occurring in approximately 5 % of children with bladder diverticulum. However, vesicoureteral reflux is more common, affecting 8 to 13 % of patients (Fig. 6.8).

Several reports have been published describing bladder diverticula presented in inguinal hernia. In infants, the bladder assumes a more abdominal position, which places it in close proximity to the internal inguinal ring. With growth, the pelvis becomes more developed, and the bladder assumes a more pelvic position. Therefore, this is rarely observed in adults. Fact about this entity is important to surgeons during inguinal herniorrhaphy because partial or near total cystectomy may be performed under the mistaken notion that this was a large hernia sac.

Neoplasia occurs in 2–7 % of bladder diverticula; tumors are often large because the location is hidden. All variants of urothelial carcinoma have been reported in bladder diverticula, with a relatively higher frequency of unusual subtypes when compared to the general population [18].

Voiding cystogram shows the number, location, size, and urinary retention volume of the diverticulum. However, a voiding cystourethrogram with lateral and oblique projections will be indispensable when a urethral obstructive cause is suspected or in congenital cases to rule out possible VUR. CT or MRI scan can also be used in complex malformations or complicated cases.

Cystoscopy will show the diverticular exact site (may be difficult to recognize and concern multiple diverticula), relation to ureteral and urethral orifices, dynamics of the diverticulum during bladder emptying and filling, epithelial changes of the diverticular lining, and the associated bladder changes, e.g., trabeculation and hypertrophy.

Absolute indications for open surgery are:

Open diverticular excision can be done in three different approaches: extravesical, intravesical, and the combined intravesical and extravesical. Saccules and small diverticula may be treated successfully by electrocoagulation of their mucosa with the ball electrode when the primary obstructive disease is treated. Laparoscopic bladder diverticulectomy is feasible; however, the indications are limited with regard to associated conditions, size, site of the diverticulum, and the child surgical history [19].

Failure of migration of the mesoderm to the area of the cloacal membrane, and subsequent lack of development of an intermediate layer between its inner (endodermal) and outer (ectodermal) layers, leads to rupture and exposure of an open bladder plate and urethra. These structures occupy a triangular space between a low-set umbilicus superiorly, split rectus abdominis muscles on each side, and an open pelvic ring inferiorly, resulting in a bladder exstrophy.

It may be associated with phallus anomalies as bifid penis or scrotum or sequestrated intestinal remnants at the dome of the bladder. It is less distressing and easier to manage than classical exstrophy of the bladder. Sometimes as in Fig. 6.11 the bladder is seen protruding outside the pelvis with a thin skin coverage (Fig. 6.12).

Genital abnormalities observed in females with covered exstrophy included bifid clitoris (67 %), labial cleft (11 %), hypoplastic labia (11 %), and stenosed duplicate vagina (11 %) [23].

Covered exstrophy differs from the pseudoexstrophy variant in that there is an associated isolated ectopic bowel segment present on the inferior abdominal wall near the genital area. This segment is usually a segment of the colon and has no communication with the underlying gastrointestinal tract. In Fig. 6.13 a baby presented with closed exstrophy with a sequestered colonic tissue between the umbilical contents.

Superior vesical fissure is a variant in which a pelvic deformity occurs, but only the upper bladder is open near the umbilicus. In a large series of classic exstrophy, only one superior vesical fissure was found among the 72 patients [25] (Fig. 6.14).

Because of the presence of a normal urethra in the superior vesical fissure, the long-term prognosis for continence is very high, unlike patients with classic bladder exstrophy. Superior vesical fissure has been described in both male and female subjects, in association with trisomy 18, omphalocele, and duplication of the urethra.

The bladder mucosa on the anterior abdominal wall may increase the patient’s risk of adenocarcinoma of the bladder, more than that seen in classic exstrophy. Most of the cases of adenocarcinoma of the bladder in exstrophy patients occur between the third and sixth decades of life [26].

Duplicate exstrophy is one of the rarest variant, and only 23 cases are reported in literature so far [27].

True duplicate exstrophy as defined by Marshall and Muecke refers to a suprapubic exstrophic mucosal plate that is associated with a subjacent covered bladder and a relatively well-formed phallus. The exstrophic plate did not receive ureters and there was no epispadias (Fig. 6.15).

Embryologically, it represents part of the spectrum of superior vesical fissure in which the underlying fissure has fused, leaving only an overlying bladder mucosal plate [28].

Pelvic MRI provides adequate information about the internal genitalia before and after surgery; therefore, MRI is mandatory before repair.

Opinions differ about the possible existence of a continuum of abnormalities ranging from epispadias to bladder exstrophy to cloacal exstrophy.