Augmentation Cystoplasty

Bladder augmentation, also called augmentation cystoplasty, is a surgical procedure used in adults and children who lack adequate bladder capacity or detrusor compliance.[1, 2, 3] For many patients, augmentation cystoplasty can provide a safe, functional reservoir that allows for urinary continence and prevention of upper tract deterioration.

Both neuropathic and non-neuropathic causes for severe bladder dysfunction exist in pediatric and adult populations. Neuropathic causes include the following:

• Spinal cord injury

• Multiple sclerosis

• Myelodysplasia

• Tethered spinal cord

Nonneuropathic causes include the following:

• Detrusor instability

• Chronic cystitis, including tuberculosis and schistosomiasis

• Interstitial cystitis

• Radiation cystitis

• Classic or cloacal exstrophy

• Defunctionalized bladder in a patient who is on dialysis

Decreased bladder capacity or abnormal compliance may manifest as debilitating urgency, frequency, incontinence, recurrent urinary tract infections (UTIs), pyelonephritis, or progressive renal insufficiency.

Various studies used to evaluate such symptoms may reveal severe dysfunction. Urodynamic studies demonstrate a low-volume, poorly compliant reservoir, which places the kidneys at risk from high-pressure urinary storage. Simultaneous fluoroscopic videourodynamic evaluation may reveal vesicoureteral reflux. Renal ultrasonography or other imaging modalities may show renal scarring or impaired renal growth due to high-pressure urinary storage.

Any patient with marked reduction in bladder capacity or compliance may be a candidate for augmentation cystoplasty. Conservative management for these patients usually consists of intermittent self-catheterization[4] and anticholinergic medications. In general, augmentation cystoplasty is considered when bothersome symptoms impair a patient’s lifestyle despite medical treatment or when high-pressure urinary storage places the upper urinary tracts at risk. In an updated clinical guideline, the American Urological Association stated that augmentation cystoplasty may be considered for patients with severe, refractory, complicated overactive bladder.[5]

Neurogenic bladder in the pediatric population is often associated with congenital anomalies, including the following:

• Spina bifida/myelomeningocele[6, 7]

• Posterior urethral valves

• Prune belly syndrome (Eagle-Barrett syndrome)

• Bladder exstrophy

• Cloacal exstrophy

Patients with these conditions most commonly undergo augmentation cystoplasty when, despite behavioral and medical management, they experience continued incontinence, debilitating urgency, enuresis, complicated UTIs, vesicoureteral reflux, or impaired renal growth.

Some adult patients who underwent urinary diversion for an embryologic urinary defect as a child seek a healthier cosmetic and functional state. In other cases, adults have an acquired condition that is causing bladder dysfunction. Adults may present with symptoms very similar to those of children with congenital abnormalities. Again, surgery is indicated for adults with refractory symptoms and those with risk or progression of upper tract deterioration.

Patients who are unable or unwilling to perform life-long intermittent catheterization should not undergo augmentation cystoplasty, because of the high likelihood that catheterization will ultimately be required.

In addition, patients with inflammatory bowel disease (especially Crohn disease), a short or irradiated bowel, bladder tumors, severe radiation cystitis, or severe renal insufficiency should not undergo augmentation cystoplasty.

Poor surgical candidates and patients with a short life expectancy should consider alternatives to augmentation cystoplasty, such as continued medical management or creation of a less complex, temporizing form of urinary drainage.

The anatomy of the bladder forms an extraperitoneal muscular urine reservoir that lies behind the pubic symphysis in the pelvis. A normal bladder functions through a complex coordination of musculoskeletal, neurologic, and psychological functions that allow filling and emptying of the bladder contents. The prime effector of continence is the synergic relaxation of detrusor muscles and contraction of the bladder neck and pelvic floor muscles.

The normal adult bladder accommodates 300-600 mL of urine; a central nervous system (CNS) response is usually triggered when the volume reaches 400 mL. However, urination can be prevented by cortical suppression of the peripheral nervous system or by voluntary contraction of the external urethral sphincter.

Before being considered for augmentation cystoplasty, patients should have timed voids as often as necessary to maintain low bladder volume and pressure.

Anticholinergic medications (eg, oxybutynin, hyoscyamine, or tolterodine) may be given to decrease detrusor instability and symptoms of urgency. Medical management also allows increased bladder volume to protect renal function and to decrease the chance of pyelonephritis. The increase in bladder capacity with medical treatment has been modest (generally < 50 mL), but some groups have found that higher doses may increase the effect, as one study demonstrated in young children with neurogenic bladders.[8]

Cystoscopic injection of botulinum toxin (botox) can also decrease involuntary detrusor contractions and increase functional capacity. In the setting of poor bladder capacity and outlet obstruction, botulinum toxin can be added to a regimen of clean intermittent catheterization.

Lack of coordinated detrusor contraction or increased bladder outlet obstruction (eg, external sphincter dyssynergia) can be overcome with intermittent self-catheterization at 4- to 6-hour intervals. This usually reduces bladder pressure and improves continence. Adult patients should have good manual dexterity, proven by performing self-catheterization in front of the physician. In pediatric patients, the parents must be committed to catheterizing the child at least every 4-6 hours. Parents must be taught catheterization before surgery.

Intermittent catheterization and anticholinergic management are usually used in combination to accomplish symptom-management goals, to create continence, to eliminate vesicoureteral reflux, to prevent UTIs, and to ensure low bladder storage pressure. If these measures fail, augmentation cystoplasty should be considered.

In properly selected patients, augmentation cystoplasty is an excellent procedure that provides a safe and effective way of improving urinary storage. Bladder emptying is almost universally impaired, and the patient must be prepared to perform lifelong intermittent catheterization. The patient and physician must recognize the need for surveillance to identify potential problems. Stones, metabolic and nutritional abnormalities, renal insufficiency, and malignancy are best treated through early recognition and prompt therapy.[9, 10]

Herschorn et al, using a survey to address complications and patient satisfaction in an augmentation cystoplasty population, found that at a mean of 6 years after surgery, 41% of the patients had 1 or more complications, with 36% of all patients requiring intervention.[11] Most took medications (eg, anticholinergics, antidiarrheals, or antibiotics). Of 59 patients, 56 required clean intermittent catheterization at a mean interval of 4.6 hours; 18% had postoperative bowel dysfunction, and 7% had preoperative dysfunction.

Schlomer et al analyzed 1622 augmentation cytoplaties performed on children between 2000 and 2009. A complication was identified in 30% of patients. Longer hospital stays and increased risk for having complications were associated with older age and bladder exstrophy-epispadias complex diagnosis.[12]

Alternative approaches

McGuire et al compared patients treated with augmentation cystoplasty to patients treated with autoaugmentation and determined that whereas autoaugmentation causes less morbidity, commonly reduces symptoms, and routinely improves bladder compliance, the gains in bladder capacity were much less than those seen with augmentation cystoplasty.[13]

This study stratified patients by etiology of bladder dysfunction and compared urodynamic and symptomatic improvement.[13] Patients with myelomeningocele did not fare as well with autoaugmentation because of the smaller increases in bladder capacity, and augmentation cystoplasty was more beneficial in these patients. Reportedly, autoaugmentation was unsuccessful in 27% of the patients who required augmentation cystoplasty.

Hedican et al used laparoscopy to mobilize the intestine in complex pediatric procedures, including augmentation cystoplasty.[14] They found laparoscopy useful in mobilizing the right colon and in isolating the appendix for a continent catheterizable stoma. A smaller lower-midline or Pfannenstiel incision can be used for surgery on the bladder or for re-establishment of bowel continuity.

Laparoscopic autoaugmentation has also been shown to be technically feasible. Braren and Bishop performed laparoscopic autoaugmentation in 7 pediatric female patients aged 3 months to 15 years; bladder capacity increased 55-95%, all 7 patients showed symptomatic improvement, and 6 of the 7 were completely dry.[15]

With the advent of robotic instruments with increased range of motion and the facilitation of intracorporeal suturing, many reconstructive procedures including bladder augmentation have become more amenable to fully laparoscopic procedures.[16] These procedures may decrease morbidity, reduce intra-abdominal adhesions, and improve body self-image.

Preoperative evaluation

Urine analysis, urine culture, and cytology (in adults) allow proper preoperative treatment of infection and investigation of potential occult malignancy. Sterile urine at the time of surgery is crucial in all patients, especially those with ventriculoperitoneal shunts.

Obtain a serum chemistry panel to rule out metabolic acidosis and to allow for assessment of renal failure with and without surgical therapy. Conduct a complete blood cell count to identify anemia or infection.

The kidneys and upper urinary tract should be imaged with renal ultrasonography to identify any upper tract anomalies and assess the renal parenchyma. In the presence of hydronephrosis, upper tract obstruction (eg, ureteropelvic junction obstruction) should be ruled out in addition to lower tract pathology.

Voiding cystourethrography should be performed to evaluate bladder size and contour, the presence of any diverticula, the anatomy of the bladder neck, and the presence of vesicoureteral reflux. This can also be performed as part of videourodynamic evaluation.

Assess urinary continence with a voiding diary and Valsalva leak point pressure.

Urodynamic evaluation should be performed if the patient has a history of dysfunctional voiding, though some surgeons perform this test in all patients in whom augmentation cystoplasty is being considered. Consider fluoroscopic video monitoring to assess for vesicoureteral reflux and to determine the bladder pressures at which reflux occurs.

Twenty-four–hour urine-volume assessment helps in planning the final reservoir size.

Cystoscopy, which can be performed immediately before augmentation cystoplasty under the same anesthesia, is useful for identifying occult urethral valves, strictures, or unsuspected bladder pathology.

Colonoscopy or barium enema may be considered in an older patient who has the potential for diverticular disease or colon cancer. This is even more important if the large intestine is the planned segment for augmentation cystoplasty.

Planning for concomitant procedures

Some patients who are candidates for augmentation cystoplasty also have ureteral reflux. Patients who have bladder exstrophy and who require augmentation cystoplasty should undergo simultaneous ureteral reimplantation. These patients have abnormal ureteral insertions to the bladder, and with bladder neck repair for continence, they often have elevated bladder pressures. Thus, tunneled reimplantation is almost universally performed, usually in a cephalad manner toward the bladder dome so as to follow the course of the ureter.

The role of ureteroneocystostomy in other patients is less clear. In patients with reflux at high bladder pressures, the augmentation procedure ideally resolves the issue. However, if low pressure causes reflux, the problem may persist after augmentation.

If a patient has grade 4 or 5 ureteral reflux at bladder-filling pressures lower than 40 cm H2O, tunneled ureteral reimplantation into the native bladder tissue should be more strongly considered. Patients with low-grade reflux (ie, grade 1 or 2) at higher bladder pressures may undergo augmentation in the hope that the reflux will resolve with decreased bladder storage pressures.

A history of renal scarring, a history of pyelonephritis, the level of renal function, and the patient’s willingness to undergo future surgery should all be considered in counseling patients and parents and deciding whether to perform concomitant ureteral reimplantation at the time of augmentation cystoplasty.

In adult patients for whom a continent catheterizable stoma is planned, some surgeons routinely perform bladder-neck closure; however, if the outlet is intact and continent, it should be maintained to provide an alternative route for catheterization. Many surgeons feel that surveillance endoscopy is much easier in patients with an open bladder neck.

Associated urologic or gastrointestinal (GI) issues arising from congenital anomalies or acquired neurologic impairment may necessitate concomitant procedures. Urinary continence can be achieved with an artificial urinary sphincter (in males) or a urethral sling placement (in females). Construction of a continent catheterizable stoma assists with urinary emptying. A Malone antegrade catheterizable enema (MACE) procedure is used for neurogenic constipation.

In a small uncontrolled study, De et al discussed augmentation cystoplasty as an ancillary procedure to salvage prostatectomy after failed radiation therapy for localized prostate cancer; continence was improved, and 7 of 9 patients responding to a quality-of-life questionnaire stated that they would undergo the operation again.[17, 18] Because of the risk of high-bother urinary incontinence, the authors studied salvage prostatectomy with concomitant ileal augmentation, bladder neck closure, and creation of a catheterizable appendicovesicostomy.

In patients undergoing retropubic prostatectomy as primary treatment for prostate cancer who are at high risk for bladder dysfunction due to longstanding outlet obstruction, concomitant bladder augmentation is also an option.

Selection of tissue for augmentation cystoplasty

Proper selection of the optimal tissue for augmentation cystoplasty (see Table 1 below) begins with analysis of the patient’s anatomy and comorbidities but also requires consideration of intraoperative anatomic findings. One should always be prepared to use alternatives to the planned augmenting segment if the patient’s anatomy is unfavorable for the planned procedure.

Table 1. Comparison of Tissues for Augmentation Cystoplasty (Open Table in a new window)

Gastrocystoplasty may be considered in patients with renal insufficiency (creatinine level > 2 mg/dL) or significant metabolic acidosis. Using a gastric segment does not appear to worsen the acidosis and may preserve renal function. However, this procedure can be difficult to perform, it does not eliminate the risk of severe electrolyte abnormalities, and a significant number of these patients experience dysuria.

Patients who have a reduced amount of intestine (eg, anomalous short gut, previous intestinal removal, or cloacal exstrophy) may also be considered for augmentation cystoplasty with stomach rather than intestine. In patients with short gut or cloacal exstrophy, ileum is also commonly used for Mitrofanoff channel and augmentation, with GI consultation.

Ureterocystoplasty is a favorable option in patients with a massively dilated ureter; the use of ureteral tissue curbs the electrolyte imbalance and mucus production observed with intestinal segments. If the ipsilateral kidney is minimally functional, nephrectomy can be performed at the time of surgery.

With removal of the ileocecal valve, patients with neuropathic causes of bladder dysfunction (eg, spina bifida) may experience severe diarrhea that can cause fecal incontinence; thus, the combined use of distal ileum and cecum is discouraged in these patients.

In general, ileum and large intestine both handle well surgically and make excellent intestinal segments for augmentation. However, they both produce mucus and can have problematic peristalsis if not properly detubularized. Both types of augmentation segment have been well tested, and the choice of one over the other is largely a matter of individual surgical preference.

Some patients with neurogenic bowel dysfunction have a redundant sigmoid colon, which is therefore the segment of choice. In addition, this is the preferred segment in patients who do not require a continent catheterizable stoma.

Jejunal augmentation segments are rarely used, because of the importance of the jejunum in nutritional absorption and the severity of electrolyte abnormalities associated with the use of jejunal tissue.

If a patient or their caretaker is poorly compliant, an incontinent ileovesicostomy (ie, an ileal chimney with stoma) may be considered as a means of reducing the risk of perforation. This can be reversed when the patient can responsibly and independently manage the catheterization schedule.

Alternative tissue sources

Desai et al used ureteral tissue balloon expanders before laparoscopic bladder augmentation in a porcine model.[19] Basic science researchers continue to investigate potential alternatives to autologous tissues for augmentation cystoplasty. Small-intestine submucosa and synthetic polymeric substances are being studied. Tissue-engineering efforts continue, though reproducing the elastic and contractile properties of the bladder is challenging. Tissue engineering with nanostructured polymeric scaffolds appears promising.[20]

The use of any such surfaces could expand bladder volume and decrease bladder compliance without the morbidity and potential complications of intestinal harvesting. Potential benefits would include decreases in complications, operating time, metabolic derangements, and deleterious effects on bowel function.

Bowel preparation

All patients undergoing augmentation cystoplasty require preoperative mechanical and antibiotic bowel preparation.[21] Patients stay on a clear liquid diet for 2 days prior to the operation and take magnesium citrate the night before surgery.

Preoperative inpatient hospital admission should be planned for patients with renal insufficiency, chronic constipation, or a high risk of dehydration so that intestinal evacuation can be performed with concomitant monitoring and treatment of serum electrolytes and fluid status.

Scheduled oral erythromycin base and neomycin are often administered the night before surgery, and intravenous antibiotics are given 1 hour before the incision.

The patient should be seen for follow-up visits at 6 weeks, 3 months, and 6 months, then yearly thereafter. The focus is on preventing complications by monitoring with appropriate laboratory and radiologic studies.

Serum electrolytes and renal panel should be monitored to assess the level of acidosis and the potential need for correction with alkali therapy. Renal and bladder ultrasonography is used to monitor for occult obstruction or calculi formation and to confirm appropriate renal growth in pediatric patients.

Screening urine culture tests are used to check for bladder colonization with urease-producing bacteria; these species should be treated because they may cause bladder stones and have been associated with upper tract damage.

Begin bladder malignancy screening 10 years after surgery with annual cystoscopy, cytology, and biopsy if appropriate. Educate the patient about the symptoms of bladder perforation and the need for urgent treatment.

Candidates for bladder augmentation have 2 less invasive surgical options available to them that may be considered before augmentation cystoplasty is carried out:

• Cystoscopic injection of onabotulinumtoxinA

• Sacral nerve stimulation (SNS; also referred to as sacral neuromodulation)[22]

OnabotulinumtoxinA injections are used in some patients with overactive bladders and may benefit bladder-augmentation candidates. Some small studies have shown significant increases in bladder volumes, often exceeding those seen with oral medications.[23, 24, 25] However, this treatment may not be adequate or durable in patients with extremely reduced bladder compliance or volume. These injections have improved quality-of-life scores in many patients who have neurogenic incontinence despite oral anticholinergic therapy.[26]

In a small study of 26 children with neurogenic bladders refractory to conventional treatment, repeated injections of onabotulinumtoxinA failed to produce sufficient changes in urodynamic variables, with urinary continence achieved after the first, second, and third injections of 50%, 77%, and 75%, respectively.[27]

A study by Anquetil et al suggested that in patients with spinal cord injury who have a refractory overactive detrusor, those who undergo augmentation cystoplasty have a better quality of life than do those who are treated with botulinum toxin. Among the 14 patients in the study who received botulinum toxin injections and the 16 who underwent augmentation cystoplasty, the latter group scored higher on the Qualiveen-30 questionnaire. Moreover, 14 patients in the augmentation cystoplasty group (87.5%) were completely continent, compared with just 6 patients who received botulinum toxin (42.9%).[28]

SNS is a minimally invasive technique that has markedly improved bladder volume, urge symptoms, and incontinence rates in patients with detrusor overactivity and urge urinary incontinence. It has also been shown to help patients with urinary retention who have high residual volumes after voiding.

In the first stage of SNS, tunneled leads are placed, usually in the S3 foramen. After a trial of efficacy with an external device, the implantable neuromodulator is implanted in the second stage. Initial experience has shown SNS to be promising as a means of averting major surgery in adult and pediatric patients who would otherwise be candidates for augmentation cystoplasty. Long-term follow-up is limited, but the available evidence suggests that SNS should be a durable option.[29]

When medical treatment, behavioral modifications, and other less invasive options all fail, formal surgical therapy with augmentation cystoplasty is warranted. Failure is defined as debilitating urinary symptoms (eg, frequency, urgency, or incontinence) or high bladder-storage pressures (>40 cm H2O) that risk damage to the renal parenchyma.

Counsel patients regarding the risks, benefits, requirements, and lifestyle impact of the operation. When deciding among urinary conduit diversion, orthotopic bladder substitution, and augmentation cystoplasty, take into account the patient’s renal function, serum acid or base status, and potential need for dialysis. Also consider procedures that can be performed as alternatives or as adjuncts to augmentation cystoplasty, including sling procedures, urethral lengthening, appendicovesicostomy, and bladder neck closure.

Either of the following 2 methods can be used to prepare the bladder:

• A U-shaped flap can be lifted with its base anterior on the bladder

• The bladder can be opened via a sagittal incision extending from an anterior position posteriorly to the trigone

If part of the bladder is being removed to prevent symptom recurrence (as, for instance, in patients with interstitial cystitis), the bulk of the bladder may be excised around the trigone. In this case, an orthotopic bladder substitution or continent urinary diversion may be a better option. The anastomosis should be widely patent so as not to create a poorly draining diverticulum.

General principles of using enteric segments

A standard midline laparotomy incision is most often used, though a lower abdominal transverse incision can be used for some nongastric enteric segments.

Before dividing the intestine, test the mobility of the segment to ensure that it will reach the bladder without tension. Always create a vascular arcade within the mesentery to the isolated bowel segment. After reestablishing the continuity of bowel segments, mesenteric defects should be closed to prevent internal hernia formation. To prevent ischemic necrosis, small bowel should not be divided more than 8 cm from an arcade artery.

The abdomen should be packed and draped carefully to prevent contamination of the surgical field with enteric contents. Enteric segments should be irrigated thoroughly to remove gastrointestinal (GI) contents.

Intestinal segments should be detubularized by incising them with a cautery on the antimesenteric side to create a rectangular surface and to minimize forceful contractions in the augmented bladder (see the image below).

Intestinal segments should be sutured through their full thickness with a continuous absorbable suture, and the mucosal layer should be inverted. Forming the intestinal segment into a semispherical shape gives the augmented bladder maximal capacity and compliance. A wide anastomosis between the segment and the native bladder is important for optimal volume and drainage.

A suprapubic tube should be placed through the opened bladder and brought out through a separate skin incision. A drain is placed near the bladder as an indicator for urinary leakage.

Ileocystoplasty

The ileal segment should be based 15-20 cm away from the ileocecal valve to preserve the absorptive function of the terminal ileum. It should be between 15 and 40 cm long (usually about 25 cm), depending on patient age and the desired augmentation of bladder volume. A slightly longer segment is preferable to one that is too short.

Once the rectangular patch is formed, it is folded and sutured into a U-shaped cup; longer segments can be folded into S- or W-shaped cups (see the image below).

A vesicointestinal anastomosis is then performed in 1-2 layers with a 2-0 absorbable suture (see the image below).

Sigmoid cystoplasty

The sigmoid colon is the part of the large intestine that is most commonly used as an augmentation segment. A sigmoid segment should be 15-20 cm long. Because of the strength of sigmoid contractions, proper detubularization of this segment is of particular importance.

The surgical incision and exposure are similar to those used in ileocystoplasty. The sigmoid segment is inspected and palpated to ensure that no pathology is present. The flap is then folded and sutured into an S- or U-shaped segment and anastomosed to the bladder in 2 layers with an absorbable suture.

Ileocecocystoplasty

An ileocecal segment is often used for patients who require a catheterizable stoma. The terminal ileum is narrowed over a catheter, and the continence mechanism of the ileocecal valve is supported by imbrication and intussusception of the ileocecal junction.

Gastrocystoplasty

A midline incision is made from the xiphoid process to the pubic symphysis. A 10-20 cm wedge of anterior and posterior stomach is isolated, with the base along the greater curvature of the stomach. The apex should not extend to the lesser curvature, where branches of the vagus nerve can be damaged. The vascular segment used for the flap can be the right or left gastroepiploic artery; however, the right is often favored because it is more frequently the dominant blood supply to the stomach.

The stomach is reapproximated with 2 layers of absorbable sutures. Windows are created in the transverse mesocolon and the mesentery of the small intestine, and the gastric wedge is brought to the prepared bladder. Care should be taken to avoid twisting or angulating the vascular pedicle. The augmenting segment is anastomosed to the bladder with 2 layers of absorbable sutures.

Ureterocystoplasty

Ureterocystoplasty is possible only when the patient has massive ureteral dilation. The dilated ureter can be mobilized into the pelvis. The bladder is opened in the sagittal plane, and the posterior portion of the incision is directed toward the corresponding ureteral orifice.

The ureter is not separated from the bladder but is folded upon itself as a patching segment. It is then anastomose the ureter to the prepared bladder with an absorbable suture. If ipsilateral nephrectomy is not performed, care must be taken to the preserve proximal ureteral blood supply.

Other options

Autoaugmentation (also called detrusor myectomy) involves incising or excising the serosa and muscular components of the bladder dome and allowing the mucosa of the bladder to protrude. The mucosa may then be either left alone or supported by a cover of omentum or demucosalized bowel. Autoaugmentation can increase bladder volume and improve detrusor compliance without using enteric segments, thereby reducing surgical morbidity significantly.

Laparoscopic augmentation cystoplasty is becoming increasingly common at many institutions. The primary goal of this procedure is to adhere to the surgical principles of the open procedure outlined above. Many surgeons create a lower midline or transverse incision to perform some parts of the procedure extracorporeally and to assist with some of the reconstructive elements of the operation.

Intravenous (IV) fluids and nasogastric drainage are initially maintained for several days until the patient’s bowel function returns. Fluid status and electrolyte levels are monitored clinically. Nasogastric tube decompression is typically maintained until bowel function is recovered, though some studies have found that this does not decrease early postoperative complications.

Typically, a urethral Foley catheter and a suprapubic tube are used to drain the bladder, with the latter exiting the abdomen directly or through the catheterizable stoma. The bladder should be manually irrigated 3 times daily and as needed to clear mucus from the suprapubic tube and the urethral Foley catheter. The pelvic drain can be removed when concerns about urinary leakage have been eliminated, either by low output or by fluid chemistries indicating peritoneal fluid.

The patient is discharged with the capped suprapubic tube in place and a urethral catheter draining the bladder. Taping the suprapubic tube to the abdomen can prevent unintentional manipulation. Low-dose antibiotic prophylaxis is continued for about 3 weeks postoperatively, until all catheters and drains are removed. During the first few postoperative weeks, the urethral catheter is removed, and the patient should begin catheterization at 2- to 3-hour intervals. The suprapubic tube should be irrigated 3 times daily to clear mucus.

Cystography performed 2-3 weeks after surgery should confirm the augmented bladder’s integrity before the tube is removed. To avoid false-negative findings for urinary leakage, cystography should be performed with at least 300 mL of contrast.

After removal of the suprapubic tube, patients may gradually increase the interval between intermittent catheterizations to 4 hours. They should wake up at least once per night to catheterize.

Patients without neurologic deficits may try to void, but postvoid residual volumes must be checked to ensure adequate emptying.

Perforation

Approximately 6% of patients who undergo augmentation cystoplasty experience perforation.[30] These patients may present with various signs and symptoms, including acute abdomen or a vague illness with nausea, vomiting, fever, or abdominal distention. Patients are generally quite ill, and sepsis and death are possible.

Neurologically impaired patients with decreased abdominal sensation may present with different symptoms or may present later in the course than patients without neurologic impairment.

Traditional or computed tomographic (CT) cystography (imaging after retrograde administration of intravesical contrast) is the best method of evaluation if the patient is clinically stable. Patients diagnosed with perforation of the augmented bladder and those who are hemodynamically unstable with suspected perforation require urgent operative exploration and repair.

Early perforation usually occurs along the anastomosis and is usually due to poor healing or technical issues. The etiology of late perforation is unclear; however, ischemia, infection, inflammation, or overdistention may be involved. Injury with self-catheterization may be responsible for some cases of perforation. Rivas et al showed in an animal model that augmented bladders stressed with infused volume tend to rupture within the dome (7 of 11 cases) and at a suture line (4 of 11 cases).[31]

Consultation with a neurosurgeon should be considered in patients with a ventriculoperitoneal shunt who experience bladder perforation.

Urolithiasis and mucus

Stone formation, both of the kidney and of the bladder, occurs in 18-50% of patients after augmentation. Struvite is the most common stone composition; thus, treatment should be initiated immediately for bacteriuria with urea-splitting organisms.

Other risk factors for stone formation include incomplete emptying (by poor voiding or by catheterization through a stoma) and increased mucus (which can serve as a nidus for stone formation). Large intestine creates more mucus than small intestine, and gastric patches produce little mucus. Gastrocystoplasty is also slightly protective against stones because of the increased acidity, which minimizes bacteria.

At present, there are no uniform recommendations to guide the metabolic workup in patients with augmented bladders who form stones. A 24-hour urine profile for pH, volume, citrate, calcium, phosphorous, oxalate, and sodium, along with serum electrolytes and urine culture, is appropriate. A surveillance abdominal plain film obtained annually may be used to identify a few small stones before they grow into multiple large stones that require more involved treatment.

Treatment options for stones in the augmented bladder include the following:

• Extracorporeal shockwave lithotripsy

• Endoscopic fragmentation or removal through the urethra or a catheterizable stoma

• Percutaneous fragmentation or removal

• Open surgery

In addition to serving as a nidus for urolithiasis, mucus can obstruct the outlet and increase the possibility of infection or perforation. Daily irrigation may decrease the risk of these complications. Irrigants can include tap water, saline, urea, N-acetylcysteine, or 3% sodium chloride.

Metabolic derangements

Except for stomach segments, which cause hypokalemic hypochloremic metabolic alkalosis, most intestinal segments used for augmentation cystoplasty can cause metabolic acidosis (see Table 2 below).[32]

Table 2. Metabolic Changes Caused By the Use of Various Tissues in Augmentation Cystoplasty (Open Table in a new window)

Jejunal segments, which are rarely used, can cause volume contraction and hyperkalemia, whereas ileal and colon segments can cause hyperchloremia. The acidosis caused by these segments is of concern in younger patients who are susceptible to growth retardation and bone density loss due to occult or recognized acidosis. The exact mechanism has yet to be elucidated, but oral bicarbonate replacement may obviate some of these effects.

In addition, patients with baseline renal insufficiency are at significantly greater risk for the development of marked serum acidosis. This can manifest as weakness, fatigue, thirst, and failure to thrive. Screening for patients who need bicarbonate replacement is also helpful in this setting.

Because of the effects on volume and electrolytes, the use of jejunal segments is typically avoided in bladder augmentation, urinary reservoirs, and urinary conduits. The use of gastric segments may decrease the potential need for bicarbonate replacement in patients with renal insufficiency who have acidosis; however, severe metabolic derangements may still develop. Rink et al reported on episodes of severe hypokalemic hypochloremic metabolic alkalosis developing after GI illness.[33]

Hypercontractility and hypocontractility

Hypercontractility and poor compliance are more common with the use of sigmoid bowel segments but can occur with any segment despite adequate detubularization. In some cases, this complication can necessitate reaugmentation.

Hypocontractility of the augmented bladder with incomplete voiding is also a possibility that patients should understand before surgery. Patients must be physically and emotionally prepared to perform intermittent catheterization for life.

Incontinence

Incontinence may occur if the enteric segment used for augmentation provides insufficient volume or has forceful contractions. Preoperative assessment of urine output is helpful in determining the desired volume for the augmented bladder. In addition, proper detubularization is crucial to prevent forceful contractions of the enteric segment, especially when sigmoid colon is used.

Retained mucus or stones may reduce the effective volume of the augmented bladder, and urine may leak through a poorly constructed catheterizable stoma. Urinary tract infection (UTI) may also lead to detrusor instability and incontinence. Poor outlet resistance at the bladder neck or external sphincter will cause urinary leakage if it is not diagnosed before augmentation cystoplasty and addressed at the time of surgery.

Hematuria/dysuria syndrome

A symptom complex characterized by hematuria, dysuria, or both occurs with voiding or catheterization in as many as 33% of patients after augmentation gastrocystoplasty. Continence is particularly important in patients with gastrocystoplasty because of the perineal and peristomal skin irritation that can occur as a consequence of low urine pH. Patients with renal insufficiency, low urine volume (acting as acid buffer), incontinence, and a sensate abdomen and pelvis may be at an increased risk for this syndrome.

Treatment options include type II histamine blockers or proton pump blockers, and failed medical treatment may necessitate takedown and reaugmentation with ileum.

Malignancy

Augmented bladders appear to be at greater risk for malignancy.[34] Adenocarcinoma is the most commonly observed tumor, and all segments seem to be associated with the same level of risk. The average time to malignancy after augmentation is around 2 decades, but cancer has been found as early as 4 years after surgery.

For this reason, some begin surveillance cystoscopy as soon as 2 years after surgery. Filmer and Spencer recommend that patients with augmentation cystoplasty undergo yearly cytology and endoscopy and that they undergo biopsy beginning 10 years after surgery.[35] Some advocate general anesthesia during surveillance cystoscopy, on the grounds that thorough examination is crucial and should not be limited by patient discomfort.

Small bowel obstruction

Approximately 3% of patients may develop a small bowel obstruction at any time after augmentation cystoplasty. Parastomal hernia, internal hernia, and volvulus can also occur.

Diarrhea

Diarrhea can result from the removal of the ileocecal valve from the intestinal tract in the course of the augmentation procedure. This is more likely in pediatric patients with neurogenic bladder and intestinal dysfunction. Removal of the ileocecal valve may yield a decreased stool transit time or may allow retrograde colonization of the distal small intestine, with fat malabsorption in this segment. Increased delivery of bile salt to the colon may cause secretory diarrhea.

Other complications

The removal of the terminal ileum from the alimentary tract leads to compromised vitamin B-12 and bile salt reabsorption. In addition, retrograde colonization of colonic bacteria into the small bowel can interfere with absorption. These can lead to megaloblastic anemia and diarrhea.

Early satiety after gastrocystoplasty is uncommon and is usually self-resolving.

The goals of pharmacotherapy are to create continence, reduce morbidity, and prevent complications.

Class Summary

Anticholinergic medications (eg, oxybutynin, hyoscyamine, tolterodine) may be given to decrease detrusor instability and symptoms of urgency. Intermittent catheterization and anticholinergic management are usually used in combination to accomplish symptom-management goals, to create continence, to eliminate vesicoureteral reflux, to prevent UTIs, and to ensure low bladder-storage pressure. If these measures fail, augmentation cystoplasty should be considered.

Oxybutynin chloride (Ditropan XL, Gelnique, Oxytrol)

Oxybutynin chloride, a tertiary amine muscarinic receptor antagonist, is a nonspecific relaxant on smooth muscles.

Tolterodine (Detrol, Detrol LA)

Tolterodine is a competitive muscarinic receptor antagonist for overactive bladder. It differs from other anticholinergics by being selective for the urinary bladder over the salivary glands. Tolterodine has high specificity for muscarinic receptors and has minimal activity or affinity for other neurotransmitter receptors and other potential targets (eg, calcium channels).

Propantheline

Propantheline blocks the action of acetylcholine at postganglionic parasympathetic receptor sites.

Hyoscyamine sulfate (Levsin/SL, Levsin, Hyosyne, Symax SL, Levbid)

Hyoscyamine blocks the action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and the CNS, which, in turn, has antispasmodic effects. Hyoscyamine is absorbed well by the GI tract. Food does not affect absorption of this drug. Hyoscyamine is available in sublingual form (Levsin SL, Symax SL), conventional tablets (Levsin), and extended-release tablets (Levbid).

Class Summary

Agents in this class cause presynaptic paralysis of the myoneural junction and reduce abnormal contractions.

OnabotulinumtoxinA (BOTOX)

OnabotulinumtoxinA injections are used in some patients with overactive bladders and may benefit bladder-augmentation candidates. Botulinum toxin may provide relief of spasticity without the systemic adverse effects of other antispasticity agents. It binds to receptor sites on the motor nerve terminals and, after uptake, inhibits the release of acetylcholine, blocking transmission of impulses in neuromuscular tissue.

In treating adult patients for 1 or more indications, the maximum cumulative dose generally should not exceed 360 U in a 3-month period. The recommended treatment dose of onabotulinumtoxinA is 200 U per treatment, divided into 30 injections of 1 mL.