Societies for Pediatric Urology Societies for Pediatric Urology
Dialogue Archives: Urethral Suspension Procedures In Patients With Myelodysplasia
(Volume 12, Number 9, September 1989)


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Guest Editor: Jack S. Elder, M.D.
Participants: John P. Gearhart, M.D. Robert D. Jeffs, M.D. Craig A. Peters, M.D.
Editor
Richard M. Ehrlich, M.D. Professor of Surgery/Urology; Co-Chief of Renal Transplantation, School of Medicine, University of California, Los Angeles
Editorial Board
Gary E. Leach, M.D.
Stuart B. Bauer, M.D. Eric J. Zeidman, M.D. David A. Bloom, M.D.
Publisher
William J. Miller
A. Barry Belman, M<D. Chairman, Department of Pediatric Urology Children's Hospital National Medical Center, Washington, D.C.; Professor of Urology George Washington Medical School
Donald B: Halverstadt, M.D. Clinical Professor of Urology & Pediatrics University of Oklahoma College of Medicine Chief, Pediatric Urology Service, Children's Memorial Hospital, Executive Chief of Staff, State of Oklahoma Teaching Hospitals, Oklahoma City
W. Hardy Hendren, III, M.D. Professor of Surgery Harvard Medical School; Chief of Surgery, Children's Hospital Medical Center, Boston
Panayotis Kelalis, M.D.
Professor and Chairman, Department
of Urology, Mayo Clinic, Rochester, Minn.
Selwyn Levitt, M.D.
Adjunct Professor of Urology
New York Medical College;
Visiting Clinical Professor of Pediatrics
Albert Einstein College of Medicine;
Co-Director, Section of Pediatric Urology
Westchester Medical Center
Lester Persky, M.D. Professor of Urology Case Western Reserve University School of Medicine, Cleveland
Victor A. Politano, M.D. Professor and Chairman, Dept. of Urology University of Miami School of Medicine Miami, Florida
Edward Tank, M.D. Professor of Surgery & Pediatrics University of Oregon School of Medicine Portland, Oregon
Robert M. Weiss, M.D. Professor and Chief, Section of Urology Yale University School of Medicine New Haven, Conn.
Robert H. Whitaker, F.R.C.S. Consultant Urologist Addenbrooke's Hospital Cambridge, England Associate Lecturer University of Cambridge
SUBJECT OF CONTROVERSY: URETHRAL SUSPENSION
GUEST EDITOR'S NOTES:
In the management of myelodysplasia, the assessment and management of incontinence is often a difficult problem. In patients with an incompetent external sphincter in whom alpha adrenergic therapy is ineffective, several options have been available.
The artificial urinary sphincter has undergone numerous improvements and its insertion generally is straightforward in a patient who has not undergone previous bladder neck surgery. However, David Barrett recently reported that the mean number of secondary procedures in his series of children and young adults undergoing insertion of the AMS-800 sphincter was 0.56 at 3 years.1 Whether this device will be an effective long-term solution in incontinent children with myelodysplasia remains to be determined. The Young-Dees-Leadbetter (YDL) bladder neck reconstruction is another method of dealing with sphincteric incompetence. However, Rink and Mitchell, in a recent update of their experience, reported that 7 of 28 patients (25%) with myelodysplasia undergoing YDL required a secondary bladder neck procedure.2 Finally, the Kropp procedure is effective but some patients have had problems with catheterization.
There have been several reports recently of urethral suspension procedures in myelodysplasia females with results that are equal or better than those experienced with the artificial sphincter, YDL or Kropp procedures. The purpose of this issue is to review the principles of suspension procedures and why they seem to be effective in females with myelodysplasia. Also discussed is whether a sling repair might be effective in males with myelodysplasia.
A few years ago at an American Academy of Pediatricians Meeting, Bob Jeffs and John Gearhart reported on 4 patients who had undergone a suprapubic bladder neck suspension. I invited them to update their experience in this issue. Stu Bauer, Dave Bloom, and I have been performing the pubovaginal sling in selected female patients and we review our experience with it. Finally, I asked Gary Leach, who specializes in female urology and urodynamics, to discuss why suspension procedures are effective in myelodysplasia, whether one type of procedure is more effective than another, and whether they might be effective in males as well.
Jack S. Elder, M.D.
References
1.  Barrett DM, Parulkar BG: The artificial sphincter (AS-800): Experience in children and young adults. Urol Clin North Am 16:119, 1989.
2. Rink RC, Mitchell ME: Bladder neck/urethral reconstruction in the neuropathic bladder. Dial Ped Urol 10 (October):5, 1987.
JOHN P. GEARHART, M.D.
Assistant Professor of Pediatric Urology; Assistant Director of Pediatric Urology, Brady Urological Institute, The Johns Hopkins Hospital, Baltimore
ROBERT D. JEFFS, M.D.
Professor of Pediatric Urology; Director of Pediatric Urology, Brady Urological Institute, The Johns Hopkins Hospital
Suprapubic Bladder Neck Suspension
Urinary incontinence is a social handicap in the adolescent female with myelodysplasia. Urinary leakage may result from urethral sphincter inadequacy, bladder muscle hyperreflexia, and decreased detrusor compliance, either alone or in combination (Woodside, Borden: J Urol 135:97, 1986). Current urodynamic techniques permit adequate evaluation of bladder muscle function and outlet resistance. The indications for performance of suprapubic bladder neck suspension are: 1) continued incontinence on intensive pharmacologic bladder manipulation and properly performed intermittent catheterization, and 2) urethral closure pressure of 45cm of water or less ± an elevated bladder pressure at a relatively low bladder volume. Proper assessment of these patients preoperatively is essential for the success of the operative procedure.
A preoperative urethral pressure profile is obtained to evaluate the urethral closure pressure and functional urethral length. Besides urethral pressure profiles, we have also performed in the last 5 patients leak-point pressures to help evaluate urethral resistance. A CMG is also used to measure intravesical pressure at increasing bladder volumes and to rule out the presence of uninhibited contractions. All patients undergo a preoperative intravenous pyelogram and voiding cystourethrogram. Special attention is paid to the fluoroscopic appearance of the bladder neck at the time of the voiding cystourethrogram. Lastly, all patients undergo evaluation by the neurological consultant of the Birth Defects Treatment Center to rule out tethered cord syndrome.
After work up and evaluation, difficulties may arise in selecting the proper procedure for augmentation of the proximal urethra. Rink and Mitchell (Dialogues in Pediatric Urology 10:5, 1987) have shown a very acceptable continence rate with the Young-Dees-Leadbetter procedure in the neurogenic bladder group. The majority of their patients underwent intestinocystoplasty in conjunction with their bladder neck reconstructions. Also, the Kropp procedure (Urology 135:533, 1986) has shown exciting promise in the neurogenic group with lower urethral resistance. Lastly, several authors have shown that the artificial urinary sphincter is especially helpful in these neurogenic patients who can empty completely with the Valsalva maneuver. However, all of these procedures are best suited for the patient with severe sphincteric insufficiency.
The procedure begins with a vertical abdominal incision and exposure of the bladder neck and urethra. A Foley catheter was previously placed from below and the vagina is prepped and draped into the field. The bladder is opened and a single suture of 1-0 polypropylene is placed into the pubourethral fascia
YOUR RESPONSE
We'd like to hear from you and would welcome your comments, experiences, criticisms, etc. on the subject of this issue and other issues of this publication. Please send them to Richard M. Ehrlich, M.D., Division of Urology, UCLA Medical Center, Los Angeles, CA 90024.
from above (Gearhart, Jeffs: J Urol 140:1296, 1988). These sutures are left long and brought over the pubis for later use. Bladder augmentation and other associated procedures, such as ureteral reimplantation, psoas hitch, transureteroureterostomy, are then performed. At this juncture, the 1-0 polypropylene sutures are passed through the rectus fascia. The sutures are then tied above the rectus fascia at an appropriate time during the closure of the abdomen. Since all of our patients have undergone simultaneous intestinocystoplasty with their bladder neck suspension, a suprapubic tube is left in the bladder. At 2 weeks postoperativelyr a cystogram is obtained and if satisfactory, intermittent catheterization is begun and the suprapubic tube is removed.
Currently 9 patients have undergone suprapubic bladder neck suspension and intestinocystoplasty. There have been no major complications except for one patient who developed a small bowel obstruction which responded to long intestinal tube drainage. All of the patients were adolescent females. All patients are currently dry on the intermittent catheterization and oxybutynin chloride with a minimum follow-up of 9 months (range 9 to 39 months) and no evidence of upper tract deterioration. There was a mean increase in continence length of 1cm and a mean increase of 51cm of water in the urethral closure pressure in all patients.
Since all of our patients have undergone simultaneous bladder neck suspension and intestinocystoplasty, it is hard to speculate whether bladder neck suspension alone would be helpful in some patients. However, patients with a good functional bladder capacity and mild to moderate sphincteric incontinence might be good candidates for bladder neck suspension alone by either an open procedure or as a vaginal suspension-type procedure (Raz: J Urol 141:43, 1989). Certainly, our results in these patients suggest that bladder neck suspension, along with intestinocystoplasty, may be a useful continence procedure in carefully selected patients with myelodysplasia. Lastly, should failure occur, this procedure would not obviate placement of an artificial urinary sphincter, Young-Dees-Leadbetter bladder neck reconstruction, or a pubovaginal sling should incontinence recur in the future.
Evaluation. In addition to a comprehensive history regarding urinary incontinence, a careful neurologic examination is performed and compared with previous examinations because the neurologic lesion can and does change in myelodysplasia. It is also very important to assess the motivation and social surroundings of the patient.
Urodynamic evaluation aims to make 3 determinations: 1) bladder compliance and stability, 2) functional urethral length and resistance, and 3) the interaction of the bladder and urethra during filling, emptying, and increases in abdominal pressure. This evaluation consists of water cystometry, urethral pressure profilometry, and sphincter electromyography. Water cystometry is performed using a 7 or 11 French triple lumen urodynamic catheter (Bard Urologic), with the filling rate set at 20% of expected capacity per minute. This rate may need to be adjusted during the examination. Provocative measures are applied such as coughing, straining, standing, and rapid filling in order to unmask subtle bladder or urethral instability. Occluding the bladder outlet may be necessary to fill the bladder sufficiently.
Dynamic urethral pressure profilometry is conducted through the third channel of the urodynamic catheter with the bladder empty, as it is filled, and during provocative maneuvers. External urethral sphincter electromyography (EMG) is performed using a 24G concentric needle electrode placed at the level of the external urethral sphincter and recorded on a standard electromyograph. EMG responses to bladder filling, voiding, bulbocavernosus reflex, and provocative measures are routinely monitored.
Interpretation of the results of this evaluation aims to identify the components of the patient's incontinence. We have observed several patterns of urethral dysfunction and abnormal bladder-urethral coordination. One important pattern is that of incontinence developing as a result of the loss of function of the sphincter due to progressive neurologic damage. This loss is seldom reversible but prompt attention may halt its progression. A second pattern of incontinence is due to urethral resistance which is adequate at rest but unresponsive to increases in intraabdominal pressure. We have also seen patients whose urethral resistance is adequate when the bladder was empty but diminished with bladder filling, causing incontinence as the differential pressure decreases.
The role of the bladder in incontinence associated with neuropathic lesions is also important. Bladder instability or hypertonia must be identified and dealt with in any regimen to achieve continence. Failure to identify and treat significant bladder hypertonia may lead to high pressure upper tract deterioration following continence surgery.
Indications. The bladder neck sling may be used for the management of incontinence due wholly or in part to urethral incompetence unresponsive to a program of medical therapy. A regimen of clean intermittent catheterization (CIC), anticholinergic agents, and alpha agonists should be attempted. It is not always possible to predict the outcome of such a program,
CRAIG A. PETERS, M.D. STUART B. BAUER, M.D.
Division of Urology, Department of Surgery, The Children's Hospital and Harvard Medical School, Boston
Urethral Suspension Procedures
Continence in the child with neuropathic bladder dysfunction remains an elusive goal, its difficulty evidenced by the variety of inventive surgical techniques proposed for its management. One of the options available to the surgeon confronted with a child having inadequate urethral resistance is the creation of a bladder neck sling. We will discuss the use of a rectus fascia strip to create a competent bladder neck in the treatment of incontinence due to neuropathic bladder dysfunction.
SUBJECT OF CONTROVERSY: URETHRAL SUSPENSION
but some series have reported success rates approaching 80%. A sizable group of patients will not respond, however, particularly those with inadequate urethral resistance. If medical management does not achieve dryness, surgical options need to be considered. These include a bladder neck sling or suspension, bladder neck reconstruction (Young-Dees), the artificial urinary sphincter, and creating of a continent urethral tube (Kropp procedure). The ability to intermittently catheterize, although not ultimately needed in all patients, is a prerequisite to these options, even the artificial sphincter.
The bladder neck sling, using rectus fascia, may not greatly increase bladder outlet resistance, but it provides continence by raising and buttressing the bladder neck against the pubis, maintaining the bladder neck in an intraabdominal position, and by transmission of pressure to the bladder neck through the sling. The ovoid configuration of the sling directs pressure transmission to the bladder neck region. Prior surgical procedures around the bladder neck have not precluded the use of the fascial sling, although fibrosis from previous operations involving the bladder neck and urethra may reduce the chances of success. Antireflux surgery or augmentation cystoplasty may be carried out simultaneously. Although the bladder neck sling has been performed in male patients, our experience is limited to females. In our experience, the sling is particularly suited to the patient with extreme stress incontinence having urethral resistance that may permit occasional periods of dryness but is quickly overcome by small increases in abdominal pressure.
Bladder neck reconstruction, as described by Young-Dees, has had success in the management of incontinence due to exstrophy and epispadias but much less so in neurogenic incontinence. In these cases, the bladder neck and pelvic floor muscles may be atrophic or thick and fibrous and offer poor support to maintain continence. Beneficial effects are often only short-lived.
The artificial urinary sphincter (AUS) has been successful in the myelodysplastic population, but may not offer any advantage over the sling when patients require CIC to empty. The AUS entails the risks of infection, erosion, and mechanical malfunction. The sphincter requires a dextrous and compliant patient. The hazard of upper tract deterioration has been identified following sphincter placement, probably on the basis of unrecognized detrusor hypertonia or an altered detrusor response, leading to high bladder pressures.
The creation of a continent urethral tube, tunneled submucosally in the trigone (the Kropp procedure), has been introduced as a surgical option to treat incontinence. This procedure necessitates ureteral reimplantation, often requires augmentation, and puts the patient into complete retention, obligating diligent CIC. Experience, to date, has been favorable.
Surgical Technique. The rectus fascia is exposed through a suprapubic incision and either a transverse or vertical strip of fascia is marked out, 12 to 14cm
long and 1 to 1.5cm wide. A transverse strip can be harvested easily 4 to 5cm above the pubis. If a patch of fascia is to be placed vaginally, it should measure about 3cm to 4cm. Stay sutures are placed at the corners and the strip or patch cut. For suprapubic placement, the bladder neck area is exposed and the endopelvic fascia incised lateral to the urethra. This provides access to the plane between the vagina and the urethra and bladder neck. A urethral catheter, with the balloon positioned against the bladder neck, is helpful in defining the proper plane of dissection. The sling is brought around the bladder neck and through the rectus muscle and fascia above it. The ends are sutured together over the rectus fascia, snug but not taut; the urethra must be catheterizable after the sling is tied.
The combined suprapubic and vaginal approach facilitates development of the plane between the bladder neck and vagina, providing better access to the bladder neck area. The vaginal approach is best performed in the postpubertal and sexually-active female with a capacious vaginal vault who does not necessarily need an augmentation cystoplasty or ureteral reimplantation. The fascial patch is suspended from its corners using nonabsorbable sutures passed alongside the bladder neck with Stamey-Pereyra needles, and tied over the rectus fascia. Augmentation cystoplasty may be performed simultaneously.
Postoperatively, a urethral catheter and suprapubic tube are left in place for 4 to 21 days, the latter time being appropriate when an augmentation has been performed. Following this, emptying trials are begun with suprapubic tube access to the bladder and CIC. The suprapubic tube is removed only when the patient is fully able to achieve complete bladder emptying with CIC.
Experience. We have performed a fascial sling around the bladder neck in 9 females with incontinence due to myelodysplasia or sacral agenesis. Two of the patients had undergone prior bladder neck reconstructions and one had a prior bladder augmentation.
Each of the categories of urodynamic findings noted above were seen. Five of the patients were also found to have high detrusor pressures, 3 with uninhibited contractions as well. Augmentation cystoplasty was performed simultaneously in 4, the fifth was augmented previously. The average age at the time of the sling was 13 years. No specific complications have been noted. One patient experienced some psychological difficulty with CIC but this has not otherwise been a problem.
Six patients are now completely dry on intermittent catheterization with 9 to 36 months of follow-up. Two girls demonstrated a postoperative increase in maximal urethral pressure, from 15 to 20cm of water. Five patients have stable urethral pressures with bladder filling although there was no postop increase in peak urethral pressure. Two of these girls require oxybutynin and phenylpropanolamine to remain dry where they were not preoperatively, even with these drugs. Reoperative tightening of the sling was required to achieve continence in one of these 2 girls.
One girl is dry during the day but wet at night. Another girl is wet, but she requires another augmentation because a previously-placed, detubularized sigmoid patch still has intractable contractions.
The fascial sling is applicable to a variety of neurologic situations, particularly the patient with severe stress urinary incontinence and inadequate urethral resistance. Continence has been achieved in 8 of 9 (89%) patients, with a mean follow-up of 1.7 years (range: 9 to 36 months). Intermittent catheterization is needed for bladder emptying in all. Adjunctive bladder augmentation may be performed to manage the high pressure, unstable bladder. The bladder neck fascial sling is a useful option in the surgical treatment of neurogenic urinary incontinence.
made. The bladder neck dissection is performed at the beginning of the procedure, and a Penrose drain is left around the bladder neck until the sling is performed. Only one patient has required a vaginal dissection to dissect out the bladder neck. All of my female patients who have undergone the sling have also undergone augmentation cystoplasty. After the augmentation has been completed, the fascial strip is obtained. A free graft of rectus fascia measuring approximately 4x1-1.5cm is harvested. An O-polypropylene suture is used on each end and fixed to the graft with a Goretex bolster. The bolsters lie on the lateral aspect of the free graft once it is in place. The graft is brought around the bladder neck and the polypropylene sutures may be tied down together over the inferior aspect of the rectus fascia, or tied separately to Cooper's ligament on each side. The bladder is then filled with saline through the suprapubic tube. The bladder is compressed manually and increasing tension is placed on the sling until urethral leakage stops. Tension is maintained on the sling and I ascertain that catheterization can be performed without difficulty. The sling is then tied down. A urethral catheter has not been used postoperatively.
I have also performed the procedure in males with myelodysplasia. The dissection around the bladder neck is identical to that performed for insertion of an artificial urinary sphincter. The sling is placed around the bladder neck and superior aspect of the prostate. In males, it has been necessary to place greater anterior tension on the sling than in female patients.
To date, 8 female patients and 4 male patients with myelodysplasia have undergone a sling repair. Patient age ranges from 6 to 25 years {mean: 12 years); all but 1 underwent simultaneous augmentation cystoplasty. Follow-up ranges from 3 months to 2 years. All patients initially were totally continent following the reconstructive procedure, and none have had any difficulty performing intermittent catheterization.
One female patient developed a small bladder calculus 4 months postoperatively and she underwent cystoscopic evaluation under anesthesia. In an effort to visualize the stone, an assistant exerted too much downward pressure on the bladder neck and the sling failed. However, she was subsequently rendered continent with a secondary Gittes anterior urethropexy. This was the only postoperative complication. Two patients have sporadic incontinence when they have bacteriuria; one is the woman who underwent the secondary repair and the other is a male who did not undergo augmentation cystoplasty. All of the postoperative cystograms show substantial elevation of the bladder neck.
An advantage of the artificial urinary sphincter over the sling is that the patients undergoing the former procedure generally do not need to perform intermittent catheterization. However, I have found the sling to be extremely effective and reliable in achieving continence.
One question regarding the sling is its fate: Does the free graft survive or does it become nonviable and turn
JACK S. ELDER, M.D.
Director of Pediatric Urology, Rainbow Babies & Children's Hospital; Associate Professor of Surgery (Urology) and Pediatrics; Director of Pediatric Urology, Cleveland
Pubovaginal and Puboprostatic Sling Repair
In patients with myelodysplasia with uninhibited bladder contractions who are incontinent despite intermittent catheterization and maximum pharmacologic therapy, it is often difficult to determine whether augmentation cystoplasty alone will cure the incontinence, or whether an operation on the sphincter also will be necessary. There are several methods to assess the integrity of the sphincter. In general, I use urethral pressure profilometry as well as upright videocystourethrography. These studies must be done carefully and occasionally must be repeated.
Several years ago, during an insertion of an artificial urinary sphincter in a few girls with myelodysplasia, after performing the dissection around the bladder neck, I suspended the bladder neck with a Penrose drain and was impressed that this maneuver seemed to prevent urinary leakage. It became apparent that a urethral suspension procedure probably would be effective in girls with myelodysplasia with an incompetent sphincter. More recently, a young adult myelodysplastic woman with an ileal loop presented to the office requesting undiversion. She had normal upper urinary tracts, a bladder capacity of 20cc's, and an incompetent bladder neck. I thought that it would be extremely difficult to place an artificial sphincter around the bladder neck. The tiny bladder capacity precluded either a Kropp procedure or a Young-Dees-Leadbetter repair. Although an Indiana pouch was a good alternative, the patient preferred not to have an abdominal stoma and I decided to try a pubovaginal sling in conjunction with an ileocecocystoplasty. The dissection was straightforward and I was impressed by the ease of postoperative catheterization. Presently, my goal is to achieve complete dryness with one reconstructive procedure rather than simply performing an augmentation cystoplasty with plans to perform a later bladder neck procedure if the patient remains incontinent.
The technique I use follows. A midline incision is
SUBJECT OF CONTROVERSY: URETHRAL SUSPENSION
into a scar? I asked this question of Dr. Ed McGuire, who has the largest experience with the pubovaginal sling in adult women. He feels it remains intact. However, he has modified his previously-reported technique and now uses a 10cm long strip of fascia that is sutured over the rectus. A potential disadvantage of using a free graft of rectus fascia is that the abdominal wound closure might be difficult, particularly if the patient is heavy. Accordingly, fascia lata would be a reasonable alternative.
There also have been several reports of the Stamey endoscopic bladder neck suspension being effective in girls with myelodysplasia. An endoscopic bladder neck suspension would be difficult in conjunction with augmentation cystoplasty, but might be considered as a secondary procedure in patients with incontinence who have already undergone a cystoplasty or those with primary sphincteric incontinence with a large compliant bladder.
From these data and those from other authors, I think it is apparent that urethral suspension procedures are as effective as the Young-Dees and Kropp procedures in the short-term management of sphincteric incompetence in females with myelodysplasia. Whether the sling will remain effective permanently remains to be determined. I think that the puboprostatic sling also should be considered in males with myelodysplasia, particularly if they have mild sphincteric incompetence. References
1. Woodside JR, Borden TA: Suprapubic endoscopic vesical neck suspension for the management of urinary incontinence in myelodysplastic girls. J Urol 135:97, 1986.
2.  Lawrence WT, Thomas DG: The Stamey bladder neck suspension operation for stress incontinence and neurovesical dysfunction. BrJ Urol 59:305, 1987.
3.  Kato K, et al: Incontinence in female neurogenic bladders. Resolution by endoscopic bladder neck suspension. BrJ Urol 59:523, 1987.
necessitate a change in cuff size, and the unknown long-term mechanical reliability of these devices in children has prompted a search for surgical alternatives.
The sling procedure itself is relatively straightforward, requires less than one hour of operative time and has been described in detail.2'3 Several caveats should be kept in mind. In the female, the procedure is most comfortably performed through a vaginal incision, freeing completely the retropubic space on either side of the urethra. An abdominal skin incision is utilized for graft harvest, although the abdominal cavity need not be entered. Two-zero polypropylene sutures anchored to each end of the sling are transferred from the vaginal to abdominal incision. It is helpful to secure the sling to the periurethral fascia of the proximal urethra with two 4-0 absorbable sutures prior to tying the suspending sutures above the rectus fascia. This maneuver maintains the proper position of the sling and prevents its twisting upon itself. Cystoscopy confirms needle passage outside the urinary tract.
In the male, the sling is placed through an abdominal incision underneath the distal prostate just proximal to the membranous urethra so that the seminal vesicles are avoided. The placement of the assistant's finger in the rectum facilitates the dissection. Tension on the sling is determined empirically; the goal of the sling is to obtain tension-free coaptation of the incompetent urethra. Whereas the sling is not difficult in patients with normal anatomy, the dysmorphic myelodysplastic patient offers more of a challenge. Continence does not correlate well with the static perfusion urethral pressure profile. Profilometry is misleading during surgery because anesthesia relaxes periurethral smooth and skeletal muscle. In addition, intraoperative profilometry is performed in the supine position whereas continence should be determined with the patient upright. Catheterization is an important test during surgery in order to be certain that the reconfigured urethra still permits access to the bladder.
When medically-refractory hypertonicity coexists with an incompetent urethral sphincter, it may be difficult to determine whether the sling should be performed simultaneously with an augmentation procedure or at a later stage. Some suggest performing the cystoplasty first, contending that sphincteric competence may be improved by this procedure alone.4 The change in compliance may simply serve to delay the volume at which the leak-point pressure is reached. But we have witnessed the disappearance of stress incontinence after cystoplasty despite the generation of intravesical pressures above the preoperative leak point. Either mechanical or neurophysiologic factors may explain this phenomenon. The high tension developed in a poorly-compliant bladder wall may act to stretch the longitudinal fibers of the posterior urethra, opening the distal urethral sphincter. Local reflexes occurring between bladder wall and external sphincter area may be implied. By improving bladder compliance and thereby, decreasing the activity of bladder wall tension receptors, urethral resistance may increase with a simultaneous increase in leak-point pressure.
Others suggest treating the sphincteric insufficiency at the same time as cystoplasty in patients who have
ERIC J. ZEIDMAN, M.D. DAVID A. BLOOM, M.D.
The Division of Urology, Joint Military Medical Command, San Antonio; and the University of Michigan Medical Center, Ann Arbor
Use of the Fascial Sling
The pubovaginal sling is useful for true sphincteric incompetence in women. It is successful in 85 to 90% of patients and has a low complication rate.1 The sling's main role was established for the management of stress urinary incontinence in women with fairly normal bladder function, but it has been successfully extended to girls with neuropathic bladders related to spina bifida. Recently, this technique also has been used to treat myelodysplastic males with urinary incontinence secondary to a nonfunctional internal sphincter mechanism. Surgery may be contemplated in cases refractory to pharmacologic manipulation and intermittent self-catheterization. Though artificial sphincter insertion is a common approach, infection is a distinct possibility because a foreign body is sometimes placed at the time of cystoplasty with open bowel. Growth of the patient and urethral atrophy may
leakage in the upright position at low-filling volumes.5 We prefer to perform a sling at the same time as a cystoplasty in patients with upright leakage at pressures below 20cm water in the absence of a bladder contraction.
The primary disadvantage of the sling procedure in patients with neurogenic bladders is life-long intermittent self-catheterization. Another concern is the lack of a long-term experience with sling techniques in this population. The effects of both general somatic and prostatic growth on slings are unknown. A low-pressure bladder therefore must be maintained and serial, life-long upper tract assessment is mandatory. This procedure is not recommended for patients in whom clean intermittent catheterization cannot be performed, tension-free coaptation of the proximal urethra cannot be obtained, and long-term follow-up cannot be expected.
References
1.  McGuire EJ, Lytton B: The pubovaginal sling in stress urinary incontinence. JL/ro/119:82, 1978.
2.  McGuire EJ, Wang CC, Usitalo H, Savastano J: Modified pubovagfnal sling in female children with myelodysplasia. J Urol 135:94, 1986.
3.  Raz S, McGuire EJ, Ehrlich RM, Zeidman EJ, Wang CC, Alarcon A, Schmidtbauer C, McLaughlin S: Fascial sling to correct male neurogenic sphincter incompetence: The McGuire/Raz approach. J Urol 139:528, 1988.
4. Linder A, Leach GE, Raz S: Augmentation cystoplasty in the treatment of neurogenic bladder dysfunction. J Urol 129:491, 1983.
5. Gonzalez R, Sidi AA: Preoperative prediction of continence after enterocystoplasty or undiversion in children with neurogenic bladder. J Urol 134:705, 1985.
Prior to embarking on urodynamic studies in these patients, it is helpful to know the status of the upper urinary tracts (ie, is there hydronephrosis and/or vesicoureteral reflux?). Should reflux be present, performing a videourodynamic evaluation provides the most accurate information regarding the true status of the intravesical pressures. Fluoroscopic monitoring of the cystometrogram in this situation will show the urologist the intravesical pressure at which reflux and "venting" of bladder pressure occurs. Thus, a false sense of security, realized when the examiner sees only low or moderate intravesical pressures in the face of reflux, is avoided.
Prior to the age at which normal continence would be achieved, the main urodynamic question to be answered in the myelodysplastic patient is an accurate quantification of urethral resistance (which can change over time). McGuire has pioneered the concept of leak-point pressure (LPP), which is the most useful indicator of outlet resistance in this patient. Since measurement of the LPP is the most direct indicator of the degree of fixed outlet resistance present (as a consequence of the sacral arc denervation), other more tangential forms of evaluation such as the urethral pressure profile and pelvic floor electromyography are not as clinically relevant and are not performed on a routine basis when evaluating a myelodysplastic. The LPP is performed by noting the intravesical pressure at which fluid leaks around a small catheter in the urethra during the cystometrogram. When the LPP is low (less than 40cm of water), there is minimal risk of upper tract deterioration. Should the LPP be above 40cm of water, the risk of hydronephrosis, with or without reflux, is substantial and aggressive therapy must be instituted to lower the bladder pressure the ureters are working against.
When urinary continence becomes an issue, the focus of the urodynamic study expands. At this point, not only is the LPP examined, but the influence of bladder and urethral function on continence is closely examined. It is important to note that the response of the bladder to filling in the myelodysplastic is clearly related to the degree of fixed outlet resistance offered by the urethra. Almost always, low urethral resistance (low LPP) is associated with relatively normal bladder pressure during filling. Conversely, high LPP usually coexists with high bladder pressures (ie, low bladder wall compliance or detrusor hyperreflexia). However, prior to going ahead with any procedure that will increase outlet resistance in the low LPP group, it is essential to fill the bladder to physiologic volumes with bladder neck occlusion (as Jeff Woodside has described with a Foley catheter balloon on traction) to be absolutely sure that the bladder pressures are not elevated. Failure to appreciate a significant elevation of bladder pressure at volumes that would be achieved after an artificial sphincter or pubovaginal sling is performed will lead to a high risk of upper tract deterioration.
When bladder dysfunction is a significant contributor to the myelodysplastic's incontinence, treatment is focused on this aspect of the problem before addressing the urethra's contribution to the
GARY E. LEACH, M.D.
Chief of Urology, Kaiser Permanente Medical Center, Los Angeles; Associate Clinical Professor of Urology, University of California, Los Angeles
The Case for the Pubovaginal Sling
The basic neurologic lesion affecting the myelodysplastic patient with bladder and urethral dysfunction is a variable degree of sacral arc (S2-S4) denervation, with the possibility of some suprasacral neurologic pathology also affecting bladder function (ie, hydrocephalus, tethered cord, etc). The extreme variability of the degree of denervation present accounts for the spectrum of voiding dysfunction seen in these patients. This discussion will focus primarily on the ramifications of this variable denervation of the female myelodysplastic.
The main questions which must be answered urodynamically in patients with myelodysplasia are 1) prior to the age at which continence would normally be achieved, is there lower urinary tract dysfunction present which places the upper urinary tracts in jeopardy? and 2) when continence would normally be achieved, what therapy can be instituted to restore continence without creating a high risk situation in which upper tract deterioration is likely to occur? Thus, sequential, well-directed urodynamic studies, which begin at the earliest possible age, are essential for the optimal management of the myelodysplastic patient.
SUBJECT OF CONTROVERSY: URETHRAL SUSPENSION
incontinence situation. When bladder pressures are normal, but incomplete emptying alone is the problem (which is rare), clean self-intermittent catheterization is instituted. More often, incontinence related to high bladder pressure (low compliance, detrusor hyperreflexia, or both) is seen. Initial attempts to lower intravesical pressure consist of anticholinergic therapy (single or double agents) with intermittent catheterization. Effective lowering of the bladder pressure at physiologic volumes must be demonstrated before addressing the urethral dysfunction. When this approach fails, consideration should be given to augmentation cystoplasty in conjunction with whatever procedure will be utilized to enhance urethral function.
After the situation with regard to the bladder's storage capacity and pressures is appreciated, a suspension or sling procedure can be considered to eliminate the stress incontinence usually seen in a myelodysplastic female (especially when LPP is low). In order to clarify which procedure is appropriate, the type of stress incontinence that is present is documented with either a videourodynamic study or a standing cystogram after bladder pressures have been examined. Two questions must be answered with regard to stress incontinence in this group: 1) Is stress incontinence present, ie, is there loss of fluid during stress at normal bladder pressure without a bladder contraction? and subsequently, 2) Is urethral function relatively intact (Type II stress incontinence) or is the denervation so severe that the intrinsic function of the urethra is compromised (Type III stress incontinence)? On the video study, the Type II urethra will only open significantly with stress, but the Type III urethra will be wide open at rest (which is the most common finding). This differentiation is important since the female with Type II SUI has enough preservation of urethral function so that restoring urethral support with a routine type of bladder neck suspension procedure will eliminate the SUI. Conversely, when Type III SUI is documented, the urethral denervation is so severe that even if urethral support were restored, resolution of the SUI is unlikely since the intrinsic function of the urethra is severely compromised. In this situation, a pubovaginal sling is the preferred treatment.
The pubovaginal sling is performed by harvesting a transverse strip of anterior lower abdominal wall fascia 2cm in width. An anterior "U" shaped vaginal wall incision is made with the apex of the "U" at the mid-urethra. An anterior vaginal wall flap is created and reflected proximal to the bladder neck. Dissection is performed beneath the vaginal wall on each side at the level of the bladder neck, laterally to the pubic bone. The deep endopelvic fascia is perforated on each side, and the retropubic space is entered and mobilized. Two small vertical fascial incisions are made lateral to the midline and just cephalad to the pubic bone. The fascial strip is then guided through these incisions into the retropubic space and placed beneath the proximal urethra. The sling is secured to the anterior abdominal wall with endoscopic quantification of the degree of tension required to obtain adequate proximal urethral closure.
The goal of the sling operation in the myelodysplastic
female is to restore continence with the patient maintained on a permanent program of self-catheterization. Although the exact mechanism by which the sling can reliably achieve this goal is controversial, it most likely works by creating some degree of outlet obstruction. Thus, as mentioned above, it is important to cystometrically follow these patients on a long-term basis after surgery to be sure that the bladder pressures are not increasing as a result of the alteration in outlet resistance. The ability of the sling to reliably restore continence in the female with Type III SUI makes it a particularly attractive treatment option. When compared with the artificial urinary sphincter, the sling is preferred since there is no risk of device failure, atrophy, or other complications inherent to prosthetic devices.
There has also been preliminary experience reported of the use of the sling in the male myelodysplastic with stress incontinence. Again, when successful, placement of the fascial strip around the proximal male urethra probably functions by inducing some degree of obstruction. Before the sling can be considered a viable treatment option in the male myelodysplastic, longer-term results in a significant number of patients must be made available.
EDITOR'S COMMENTS
It is difficult to construct an issue such as this one where there are so many diverse approaches to this complex problem. Our own fascial sling procedure (Raz S, McGuire E, Ehrlich RM et al, J Urol 139:528, 1988) has stood up well in these difficult management situations. We continue to employ it and are pleased with the results.
There are a few situations in pediatric urology where precisely performed and interpreted urodynamic studies are so helpful and I am indebted to Shlomo Raz for his insightful, gifted and innovative approaches in this difficult patient cohort.
It is clear that, as with other aspects of continent diversions, we are improving our ability to make children dry. I have no doubt that this goal will be realized in the next decade and we will witness a continent state even in the most trying situations.
We applaud and thank Jack Elder and his coauthors for sharing their experiences and expertise with us in this issue which is certain to be saved and referred to by all of us.
Richard M. Ehrlich, M.D.
Opinions expressed in this publication are the sole responsibility of the individuals named and do not necessarily reflect the opinions of the editorial board or the publisher and members of this organization.
Copyright © 1989 by William J. Miller Associates, Inc.
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