J. Keith Light

Le bag:Total replacement of the bladder using an ileocolonic pouch

Creation of an ileocolonic pouch for total bladder replacement is described in 4 patients, resulting in a highly compliant, low pressure bladder. Previous experience with bowel segments for bladder augmentation and replacement have been plagued by unpredictable bowel contractions with urinary incontinence as well as potential for renal damage. A reliable method to achieve a highly compliant, low pressure system requires disruption of directional bowel peristalsis, which this technique has succeeded in achieving. The operative technique, bowel dynamics, renal status and clinical results are described. The ileocolonic pouch offers a low pressure reservoir for total replacement of the bladder in selected patients.

Management of Urinary Incontinence after Prostatectomy with the Artificial Urinary Sphincter

A total of 37 patients underwent implantation of the artificial urinary sphincter for urinary incontinence after prostatectomy. Followup was 4 to 96 months, with a mean of 37 months. Social continence was achieved in 94.5 per cent of the patients. No abnormality of detrusor function was found in any patient. Prior pelvic irradiation appears to increase the risk of cuff erosion. Routine nocturnal deactivation of the device together with primary deactivation is recommended to decrease the incidence of cuff erosion in this patient group.

Impact of the New Cuff Design on Reliability of the AS800 Artificial Urinary Sphincter

The effect of 2 cuff design changes on the mechanical reliability of the current AS800 artificial urinary sphincter was assessed in 126 patients. The surface-treated cuff was introduced in 1983 and the narrow-back design was introduced in 1987. Mean followup for the surface-treated cuff was 40 months, while that for the narrow back was 27.2 months. The incidence of cuff leaks was 1.3%, while the revision rate for clinically significant pressure atrophy, in the absence of a bladder flap urethroplasty, was 2.3%. The overall revision rate for clinically significant pressure atrophy was 9%. No leaks involving the balloon or tubing occurred. The mechanical reliability of the current AS800 artificial urinary sphincter has improved significantly.

Alteration in Detrusor Behavior and the Effect on Renal Function Following Insertion of the Artificial Urinary Sphincter

The neuropathic bladder may exhibit altered function following insertion of the artificial urinary sphincter. Detrusor hyperreflexia worsened in 7 patients following implantation of the device. However, the hyperreflexia may improve spontaneously once healing is complete. Detrusor areflexia with functional diminished compliance may remain unchanged (3 patients) or show an increased graphic gradient (10) postoperatively. These changes may result in hydronephrosis (3 patients) or urinary incontinence depending on the temporal relationship between the cuff pressure and the intravesical filling pressure. Possible explanations for the postoperative deterioration in the compliance are activation of the short neuron system, an increase in the alpha-adrenergic response or sensory receptor adaptation coupled with a severe partial lesion of the long neuron system. Because of the propensity for these changes to occur long-term followup is necessary.

The AMS 700 Inflatable Penile Prosthesis: Long-Term Experience with the Controlled Expansion Cylinders

A total of 214 patients underwent implantation of the AMS 700 penile prosthesis with the controlled expansion cylinders. Followup ranged from 9 to 86 months, with a mean of 56 months. Life table analysis to calculate the probability of the cylinder and the device as a whole surviving 6 years revealed 97% for the cylinder and 90% for the device as a whole. No aneurysmal dilatation of the cylinders occurred. The incidence of cylinder leak was 0.7%. The infection rate in patients undergoing primary implantation of the device was 0.5% compared to 6.6% in patients undergoing revision surgery. The controlled expansion cylinders have significantly reduced the incidence of mechanical failures and, thus, the need for reoperation. As a consequence of the decreased need for reoperation the incidence of device infection has also decreased.

Reconstruction of the Lower Urinary Tract: Observations on Bowel Dynamics and the Artificial Urinary Sphincter

In 14 patients the lower urinary tract was reconstructed using bowel and the artificial urinary sphincter. Of these patients 11 underwent augmentation cystoplasty. The ileocecal segment was used in 4, cecum in 4 and ileum in 3. Total reconstruction of the lower urinary tract was done using the sigmoid colon in 2 patients and an ileocecocolonic segment in 1. Significant bowel contractions were seen in all segments of the large bowel, including the ileocecal segment, which resulted in urinary incontinence in 3 patients with the artificial urinary sphincter and reflux in 3. The ileal cup-patch technique consistently produced low bladder pressures with excellent compliance and an adequate volume. Because of the unpredictable bowel contractions observed in the ileocecal, sigmoid and cecal segments we recommend that augmentation cystoplasty be performed using the cup-patch technique. This procedure will ensure the virtual absence of bowel contractions, and is associated with excellent compliance and capacity.

Immunohistochemical and ultrastructural study of rhabdosphincter component of the prostatic capsule

PURPOSE There has been no complete agreement on functional anatomy of muscular components of the urethral sphincteric mechanism, particularly in the male patient. The prostatic capsule was studied to define its histological structure and to determine whether its rhabdosphincter component (prostatocapsular rhabdosphincter) consists only of slow twitch or slow and fast twitch striated myofibers. MATERIALS AND METHODS We studied 11 whole prostates, including 1 obtained at autopsy and 10 by radical prostatectomy. Samples of prostatic capsule from 4 operative specimens were studied by electron microscopy. Whole mount paraffin sections from transverse slices of the remaining 7 prostates were double labeled with avidin biotin conjugate immunostaining using the primary monoclonal antibodies anti-alpha smooth muscle actin plus anti-alpha sarcomeric actin (all striated myofibers) or antiskeletal myosin fast (fast myofibers only). Tissue components of the prostatic capsule, including smooth muscle and slow versus fast twitch striated myofibers, were quantified by computerized image analysis. RESULTS The prostatic capsule consisted of collagen, smooth muscle and striated myofibers. It varied in thickness and proportion of the 3 components among specimens, and in each in relation to transverse circumferential aspect and craniocaudal (horizontal) level of the prostate. Collagen and smooth muscle were equally important components. Striated muscle elements within the capsule consisted of fast twitch and dominant slow twitch myofibers, and were much more abundant in the caudal (distal, lower) than the cranial (proximal, upper) half of the capsule, where they were deficient ventrally (anteriorly) and dorsally (posteriorly). The prostatocapsular rhabdosphincter thus had a butterfly-like appearance, with a thick posteriorly open ring at the apex and 2 thinner, divergent leaflets tapering toward the base at the bladder neck. The fast myofiber population decreased progressively from apex to base of prostate. CONCLUSIONS Proof is provided for mixed slow and fast twitch myofiber structure of the prostatocapsular component of human male rhabdosphincter. Sustained (tonic) contraction of slow myofibers probably reinforces the role of urethral smooth muscle in maintaining continence during bladder filling. Swift contraction of fast myofibers that abound caudally in the capsule probably supplements urethral closure by the bulkier membranous urethral part of the rhabdosphincter in preventing leakage of urine under stress when voiding is imminent or willfully withheld.

Spontaneous bladder rupture following augmentation enterocystoplasty

Spontaneous bladder rupture following enterocystoplasty has been reported recently. The etiology remains unclear but appears to be multifactorial. The common factors among the reported patients are a high outlet resistance with total urinary continence and the presence of an augmented, dysfunctional native bladder. This combination may result in the development of high intravesical pressures or increased wall tension through several mechanisms, including over-filling and active contraction in the bowel or detrusor. The presence of an abnormal detrusor may cause the wall tension to be unevenly distributed toward the bowel segment. Diagnosis requires a high degree of suspicion and prompt laparotomy with closure of the defect. Prevention depends on maintaining low bladder volumes and, thus, pressures.

Treatment of Urinary Incontinence in Children: The Artificial Sphincter Versus Other Methods

Urinary incontinence in children is a distressing problem that often is magnified during puberty, since the children then realize the full significance of the disorder. Although there are numerous methods of treatment described none offers the reliable combination of a normal body image and total urinary continence. We describe our experience with the AS792 artificial urinary sphincter in treating children with urinary incontinence of varying etiologies and compare it with other described methods.

Experience with inflatable penile prosthesis

Prosthesis surgery for management of erectile impotence has become an increasingly important aspect of urology. The inflatable penile prosthesis (IPP) provides the impotent patient with a controllable, natural-appearing and physiologically functional penis. Major modifications in the prosthesis and in the surgical implantation technique have been made since its initial introduction. In this article we present a histologic review of the IPP and our ten-year experience with it.