AIMS:
Bladder auto-augmentation by partial detrusor myectomy was developed in response to the well-documented complications of augmentation enterocystoplasty. We aimed to evaluate and compare the outcome in patients undergoing enterocystoplasty or detrusor myectomy for detrusor overactivity.

METHODS:
All patients undergoing detrusor myectomy (n=10) or ileocystoplasty (n=10) over a 28 month period were retrospectively studied. Operations were performed by a single consultant surgeon and minimum follow up was six months. Diagnosis was confirmed preoperatively by urodynamic assessment. Seventeen patients had detrusor instability. Three patients in the ileocystoplasty group were diagnosed with neuropathic hyper-reflexia. Long term treatment and failure of medical therapy had lead to consideration for surgery. Morbidity, clinical and urodynamic outcomes were compared.

RESULTS:
An overall improvement was documented in 70% (7 out of 10) of the detrusor myectomy group and 90% (9 of 10) of those undergoing ileocystoplasty. Hospital stay was comparable: Average 8.8 days after myectomy and 8.6 days after ileocystoplasty. No patients had any persistent bladder leak at post-operative cystogram performed on average 24 days later. Seven myectomy patients and eight ileocystoplasty patients required regular intermittent clean self-catheterization after removal of postoperative indwelling catheter. One patient was unable to perform urethral self-catheterization following detrusor myectomy, despite preoperative instruction. This patient underwent Mitrofanoff procedure and eventual ileal conduit diversion. Major complications were seen in only one patient from each group. A patient suffered a CVA two days after ileocystoplasty, which resulted in persistent arm weakness. One patient was readmitted with wound dehiscence ten days after detrusor myectomy and required re-closure. In the ileocystoplasty group only one patient reported significant bowel symptoms and only two suffered problems attributed to mucus production. Three patients required anti-cholinergic medication after detrusor myectomy. Two of these had no improvement and were offered ileocystoplasty, but both declined. Urodynamic assessment showed persistent instability in these three patients. One patient had persistent instability and incontinence after ileocystoplasty despite an apparently adequate increase in bladder capacity.

CONCLUSIONS:
Success rates and morbidity for both procedures in this study compare well with published data. After detrusor myectomy only two patients had no appreciable improvement, either clinically or objectively. In this series detrusor myectomy appears to compare favourably with ileocystoplasty with regard to morbidity and outcome. Prospective comparison of the techniques and their long-term outcomes is required.