Anterior innominate osteotomy in repair of bladder exstrophy

Classic bladder exstrophy is a developmental defect presenting at birth with a wide pubic separation and an exposed bladder; cloacal exstrophy involves, in addition, intestinal prolapse. Reconstruction requires several surgical procedures. The use of anterior iliac osteotomies in this process has not been reviewed in a large series.

We reviewed the results of eighty-six anterior innominate osteotomies performed in conjunction with genitourinary repair of classic and cloacal bladder exstrophy in eighty-two patients. Clinical outcome measures were successful bladder closure, achievement of continence, and maintenance of a normal gait. Radiographs of the pelvis were reviewed, and the pubic intersymphyseal diastasis (a measure of the reduction in tension on the anterior closure) was measured preoperatively and at three time-points postoperatively. Children with classic exstrophy who had undergone osteotomy and bladder neck reconstruction but not bladder augmentation were divided into four groups on the basis of the degree of continence. In addition, children with classic exstrophy were stratified according to age at the time of the osteotomy. The mean postoperative percent reduction in the amount of the original diastasis was determined for all groups.

Children with classic exstrophy and those with cloacal exstrophy had correction of the diastasis after the osteotomy, with greater correction in those with classic exstrophy, presumably because of better bone quality. Daytime continence was achieved with anterior osteotomy and bladder neck reconstruction in 74% of the children for whom continence was a goal. However, no difference in the symphyseal diastasis or in the percentage of pubic reduction was detected among the four continence groups. Children who were older at the time of the osteotomy maintained better correction over time. Wound dehiscence or bladder prolapse occurred in 4% of the patients who had osteotomy and primary closure, and the only important complication of the osteotomies was transient palsy of the left femoral nerve in seven children.

Anterior innominate osteotomy is an effective part of reconstructive repair of bladder exstrophy. The primary goals of the osteotomy are to reduce the tension in the closed bladder and the lower abdominal wall and to promote continence by restoring the sling of the pelvic floor muscles. These goals can be achieved in the majority of patients.