Longitudinal myotomy of ileum for bladder replacement in dogs

To evaluate the application of longitudinal myotomy of ileum for bladder replacement, pressure/volume characteristics of myotomized ileal segments were studied in dogs after incorporation in the urinary tract. In five dogs a 12 cm. long myotomized ileal segment was incorporated in the left urinary system as a ureteral substitute. These ileal segments did not dilate. In another six animals total cystectomy was carried out and the bladder was replaced by a 12 cm. long myotomized ileal segment. Urodynamic and radiological studies demonstrated early dilatation of these segments, leading to a four-to-five-fold increase in volume after six weeks. During filling the intraluminar pressure remained below 20 cm. H2O up to two-thirds of the maximal volume and gradually rose when filling was continued. High pressure waves were not observed. This study demonstrates that in experimental dogs longitudinal myotomy of a short length of ileum results in a high volume/low pressure urinary reservoir. This technique is easy to perform, requires less bowel compared to current reservoir techniques and leads to satisfactory reservoir function.