Surgical Management of the Incompetent Bladder Outlet in the Patient With A Eeurogenic Bladder

TERESA L. DANFORTH

DAVID A. GINSBERG

The two primary goals of treatment of patients with neurogenic bladder (NGB) include protection of the upper urinary tracts by maintaining low storage pressures and allowing the patient to sustain optimal urinary control. Incontinence may be due to bladder dysfunction (i.e., detrusor overactivity) and/or bladder outlet dysfunction. The bladder outlet in patients with NGB may behave in one of three ways: normal functioning outlet, obstructed outlet (often caused by detrusor external sphincter dyssynergia [DESD] leading to incomplete bladder emptying or urinary retention), or an incompetent bladder outlet leading to incontinence.

DESD is usually seen in patients with suprasacral spinal cord injury and is defined as involuntary contraction of the striated sphincter at the time of a detrusor contraction. This may result in obstruction from the contracted external sphincter as well as activation of the sacral arc reflex leading to a poorly sustained bladder contraction and incomplete bladder emptying. If male patients are unable or unwilling to perform intermittent catheterization (IC), standard treatment is usually reflex voiding to an external catheter which is often combined with either pharmacologic (alpha-blocker, baclofen, onabotulinumtoxinA) or surgical external sphincterotomy to maintain satisfactory bladder emptying. Patients with DESD and recurrent autonomic dysreflexia are also considered candidates for sphincterotomy to ameliorate their symptoms. Repeat sphincterotomy is commonly necessary in this population, and growth of the prostate may require subsequent bladder neck incision or resection to relieve obstruction at the bladder neck. Patients who can no longer use condom catheters secondary to body habitus may require management with an indwelling catheter.

The incompetent bladder outlet has multiple etiologies, all resulting in incontinence at baseline. Patients with sacral spinal cord injury, spina bifida, or history of radical pelvic surgery may have an incompetent bladder outlet secondary to dysfunction of the striated and/or smooth sphincters. Iatrogenic destruction of the outlet may be caused by prior transurethral resection of the prostate or chronic indwelling catheter (Fig. 38.1).

Female patients with NGB present unique challenges because women have more difficulty with IC due to inaccessible anatomy. Sphincterotomy is not an option for females with DESD because there is not an adequate external collection
device currently available. Females may also have baseline stress urinary incontinence of nonneurogenic etiology in addition to their NGB voiding dysfunction. Incontinence may be exacerbated by detrusor overactivity as commonly seen in patients with multiple sclerosis.

FIGURE 38.1 Urethral erosion. A patulous urethra caused by a chronic indwelling catheter in a female with multiple sclerosis.

This chapter will discuss the surgical options for treatment of the patient with NGB and an incompetent bladder neck, focusing on technique of bladder neck closure (BNC).

SURGICAL OPTIONS

Management of the incompetent bladder neck varies depending on the degree of incontinence and the health of the existing urethra. Options include injectables, transvaginal slings, puboprostatic slings, artificial urinary sphincter (AUS), and BNC, transvaginal or abdominal, with or without bladder reconstruction.

Patients with mild incontinence may benefit from injectable therapy (1,2,3). The few studies in the neurogenic patient population report that often multiple injections are needed with an improvement rate of up to 67% but low cure rates. None of these studies evaluate long-term efficacy. Theoretically, this would not be an optimal therapy for a patient population requiring regular IC. Long-term results in nonneurogenic patients show relatively poor durability.

Slings have been used in the management of incontinence for both neurogenic and nonneurogenic patients. Female patients with adequate urethral length may be candidates for either a mesh midurethral sling or an autologous fascial sling at the bladder neck. Male patients may benefit from a mesh sling placed in the perineum or a puboprostatic fascial sling. Little data is available on the use of male slings in patients with NGB. Groen et al. (4) recently evaluated 20 male patients who underwent the AdVance male sling and found a 65% improvement and/or cure rate. The advantage to using mesh slings in both sexes includes shorter operative time and less morbidity. However, if the sling’s purpose is to obstruct the outlet in patients who catheterize, many prefer to use fascia because it allows the surgeon to put more tension on the urethra without the risk of mesh erosion (5).

AUSs are commonly used in male patients with NGB (less commonly in females), both in those who reflex void as well as those who do IC. Patients must have adequate hand function to use the pump located in the scrotum. AUS revision rates at 5 years are approximately 20% to 25% due to mechanical failure, infection, and urethral erosion (6). Most studies regarding AUS procedures in NGB patients have been in children, with higher revision rates, upward of 36%, likely secondary to the younger ages at which the prosthesis is placed as well as increased complexity of the case (7). Herndon et al. (8) report cuff erosion rates of 16% in the NGB population, not surprisingly higher than nonneurogenic patients because many NGB patients perform regular IC.

BNC is a relatively uncommon procedure, usually reserved as a last resort. In the female patient, BNC may be performed transvaginally or abdominally.

INDICATIONS FOR BLADDER NECK CLOSURE

Females

Female patients with NGB and incontinence managed with an indwelling urethral catheter frequently suffer from leakage around the catheter, leading to upsizing of the catheter and increases in balloon volume, eventually causing a patulous urethra. Patients with sufficient urethral length may benefit from a fascial sling. Watanabe et al. (9) report that for adequate urethral compression, a patient must have an intact bladder neck and 1 cm of proximal urethral tissue. Unfortunately, this is not usually the case in many females with this issue who may have erosion up to the level of the pubic symphysis. The erosion seen in these patients may be severe enough that the bony undersurface of the pubic symphysis can be directly palpated per the urethra and one or even two fingers can be placed directly into the bladder. Other indications may include failed urethrovaginal fistula repair or severe intrinsic sphincter deficiency that has not responded adequately to prior treatments.

As opposed to the abdominal approach, transvaginal BNC is preferred in patients who have not undergone prior pelvic radiation and will be managed long term with a suprapubic tube (SPT). Prior pelvic radiation may significantly devascularize the vaginal tissue and increase risk of fistulas. If one is
planning concomitant lower urinary tract reconstruction, for example, in order to create a continent catheterizable stoma, the abdominal approach is preferred.

Males

Male patients who have failed prior treatments for incontinence or those who develop urethrocutaneous fistulas are candidates for BNC. The typical scenario that leads to BNC in men is the male patient with severe pressure ulcer disease which has involved the urethra, resulting in a large urethral defect within the pressure ulcer that is unable to be repaired. Patients who are not candidates for AUS secondary to hand function or those with severe urethral stricture disease not amenable to repair are also good candidates. BNC concomitantly with salvage prostatectomy and bladder reconstruction after radiation for prostate cancer or for complications secondary to cryotherapy has been described (10,11).

PREOPERATIVE WORKUP

The preoperative evaluation and patient selection are of vital importance to the success of BNC. History of prior pelvic, urethral, and flap surgeries and history of radiation to the pelvis should be elicited. Assessment of the patient’s medical comorbidities will help determine how extensive a procedure to pursue. Physical exam should assess a patient’s ability to be positioned appropriately in the operating room, as patients with severe contractures may make vaginal access impossible. One should also assess the skin integrity of the perineum.

If the patient has limited hand function, it is important to assess the ability to catheterize if the patient desires a continent cutaneous diversion. If unsure, referral to occupational therapy will help determine if the patient will be able to perform IC. If a patient does not want to IC, decision of an incontinent stoma (conduit versus BNC and ileovesicostomy) versus SPT will often be determined by the patient’s comorbidities and preference regarding bladder management.

Patients with chronic indwelling catheters or who are wheelchair-bound are often debilitated and malnourished. It is important to assess preoperative nutrition status because poor nutritional status is associated with poor wound healing, increased rate of infection, higher pulmonary complication rates, prolonged hospitalization, and higher mortality (12).

The bladder should be evaluated with cystoscopy, especially in patients with chronic indwelling catheters, to rule out any malignancy. If considering a continent diversion, it is important to evaluate bladder filling pressures with urodynamics. This often requires placement of a catheter balloon at the bladder neck to prevent leakage at the incompetent outlet, thus allowing the bladder to fill. Fluoroscopy will allow for assessment for any bladder diverticula or vesicoureteral reflux. Patients with elevated storage pressures may require an augmentation cystoplasty along with construction of the continent urinary stoma.

In patients with urethrocutaneous fistulas, it is often helpful to evaluate the urethra with a retrograde urethrogram with or without voiding cystourethrogram to document the extent and location of the fistula.

It is imperative to counsel the patient and the caregiver preoperatively about the options and risks of surgery. A transvaginal approach is certainly less morbid; however, it is associated with higher postoperative fistula rates than the abdominal approach (13,14,15,16,17,18). The potential need for subsequent procedures must be discussed to set appropriate expectations. Surgeon experience also must be taken into account because inexperienced pelvic surgeons might find the transvaginal approach technically challenging.

SURGICAL TECHNIQUE

BNC can be performed vaginally in women or transabdominally in both sexes. Regardless of technique, BNC requires adequate mobilization of the bladder neck, multilayer, tension-free closure with nonoverlapping suture lines and consideration of interposition of tissue over the closed bladder. The bladder can be reconstructed to allow for IC or continuous drainage via a stoma or drainage by an SPT. Specifics of lower urinary tract reconstruction will be addressed in other chapters. All patients should have preoperative urine culture to plan appropriate antibiotic coverage to sterilize urine.

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