Bladder muscle biopsy and urethral sphincter EMG in patients with bladder dysfunction after pelvic surgery

Voiding patterns in patients with post-prostatectomy incontinence: urodynamic and demographic analysis

PURPOSE

A significant percentage of patients with post-prostatectomy incontinence have been reported to void by Valsalva's maneuver, which is our observation as well. We determine the mechanism of voiding in patients with post-prostatectomy incontinence and correlate this to demographic data, urodynamic parameters and outcome after artificial urinary sphincter implantation, and identify possible risk factors.

MATERIALS AND METHODS

Videourodynamic data from 61 consecutive patients with post-prostatectomy incontinence were reviewed to determine voiding patterns. The causes of incontinence were radical prostatectomy in 58 patients and transurethral resection of the prostate followed by radiation therapy in 3. The relationship between voiding patterns and demographic data (age, diabetes mellitus, degree and duration of incontinence, history of radiation therapy or treated bladder neck contracture) as well as urodynamic parameters (bladder capacity, compliance, instability, sensation, leak point pressure and residual urine) were studied. After artificial urinary sphincter implantation outcome was assessed in relation to the voiding patterns.

RESULTS

Stress incontinence was present in all patients while concomitant urgency/urge incontinence was present in 48%. Of the patients 43 (70.5%) voided by detrusor contraction (group 1) while the remaining 18 (29.5%) voided by straining (group 2). Mean patient age +/- SD was 70.8 +/- 6.9 and 69.2 +/- 7.2 years, and duration of incontinence was 48 +/- 33 and 46 +/- 30 months in groups 1 and 2, respectively (p >0.05). Also, no significant differences were found between the groups with regard to other demographic data. Delayed first sensation (at volume greater than 140 ml.) was seen in 42.5% and 29.4%, capacity less than 300 ml. in 41.9% and 39%, impaired/poor compliance in 25.6% and 22.2%, bladder instability in 16.3% and 5.6%, abdominal leak point pressure 60 cm. H(2)O or less in 59.4% and 60% and residual urine greater than 50 ml. in 11.6% and 17.6% in groups 1 and 2, respectively (p >0.05). After artificial urinary sphincter implantation 35% and 22.2% of patients used greater than 1 pad a day in groups 1 and 2, respectively. One patient in each group reported difficulty during urination and both patients had no residual urine.

CONCLUSIONS

No identifiable demographic or urodynamic risk factors could be detected in association with the strain pattern of voiding in patients with post-prostatectomy incontinence. The absence of a difference in bladder compliance, residual urine volume and outcome after artificial urinary sphincter implantation between detrusor and strain voiders would suggest no increased risk for complications in the strain voiding group.

Apical vault repair, the cornerstone or pelvic vault reconstruction

Pelvic organ prolapse remains a difficult problem for pelvic reconstructive surgery. Before new surgical procedures can be developed a good understanding of pelvic anatomy is necessary. It is widely held that the etiology of pelvic organ prolapse is secondary to stretch neuropathy following childbirth and chronic cough or constipation. Several transvaginal and transabdominal procedures have been developed over the years. With the increasing use of laparoscopy, a new variation on existing culdeplasty techniques has been developed. Following anatomical principles, the apical vault repair reestablishes the pericervical ring at the vaginal apex. The incorporation of pubocervical fascia, uterosacral-cardinal ligament and the rectovaginal fascia provides a strong anchor for the vaginal apex. In addition, the repair should help prevent future transverse cystocele, rectocele, enterocele and apical vault prolapse. Early outcome studies suggest that the apical vault repair should be used routinely with laparoscopic urethropexy, laparoscopic hysterectomy and the repair of pelvic organ prolapse. Good apical vault support is considered the cornerstone of pelvic reconstruction.

Postprostatectomy incontinence

Post-prostatectomy incontinence is a devastating complication that is frustrating for the patient and the surgeon. Bladder dysfunction with or without sphincteric incompetence is the main cause for post-prostatectomy incontinence. Treatment based on the urodynamic evaluation is effective in restoring continence and improving the patient's quality of life.

Sphincter electromyography in patients after radical prostatectomy and cystoprostatectomy

Urethral sphincter weakness may occur after major pelvic surgery and urinary incontinence, either temporary or permanent, may result. In order to determine whether the cavernous nerves described by Donker and Walsh carry fibres to the distal urethral sphincter as well as those supplying the corporal bodies, we have studied prospectively the sphincter electromyography in 2 groups of 10 patients: (1) those who had undergone nerve-sparing radical prostatectomy for prostatic carcinoma and (2) those who has undergone radical cystoprostatectomy for bladder carcinoma. This study group was compared with a control group of normal individuals. The results showed significant differences in duration of motor units between the control group and prostatectomy group and between the control group and cystectomy group but no significant difference between the 2 operated groups. There was no significant difference in amplitude of the motor units, the sacral reflex latencies or the pudendal somatosensory evoked potentials between all 3 groups. It was therefore concluded that division of the cavernous nerve of Walsh does not compromise distal urethral sphincter function. Furthermore, radical transabdominal lower urinary tract surgery may induce significant electromyographic changes in the external sphincter which may not be clinically evident. This may potentially affect continence later if second-stage urinary reconstructive surgery is undertaken.

Studies of the neurogenic bladder

A series of 36 patients with specific neurological lesions affecting those parts of the nervous system thought to be involved in the control of bladder function have been studied by urodynamic, electromyographic and neurohistochemical means and the results compared with those obtained in 20 control subjects. In patients with pelvic nerve injury urethral sphincter electromyography (EMG) revealed abnormal motor units and the density of bladder innervation was significantly reduced (P less than 0.01). By contrast, in patients with distal autonomic neuropathy the innervation of the striated muscle of the urethra was unaffected and although there was an almost total loss of nerves from the bladder muscularis, the subepithelial plexus of nerves was preserved. In patients with progressive autonomic failure and multiple system atrophy, the bladder neck was incompetent in every case and the striated muscle of the urethra was affected by a process of denervation and re-innervation. These findings serve to distinguish patients with autonomic failure from those with idiopathic Parkinson's disease and influence the selection of patients for transurethral surgery.