You are in: eMedicine Specialties > Urology > Surgery Augmentation CystoplastyArticle Last Updated: Mar 11, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Pravin K Rao, MD, Staff Physician, Glickman Urological and Kidney Institute, Cleveland Clinic Foundation Coauthor(s): Alan J Iverson, MD, Staff Physician, Department of Urology, David Grant Medical Center; R Duane Cespedes, MD, Director of Female Urology and Urodynamics, Department of Urology, Wilford Hall Medical Center; Clinical Associate Professor, Department of Surgery, Division of Urology, University of Texas Health Science Center at San Antonio; Edmund S Sabanegh, MD, Director, Center for Male Fertility, Glickman Urological and Kidney Institute, Cleveland Clinic Foundation Editors: Michael Grasso, MD, Chairman, Department of Urology, Saint Vincent's Medical Center; Professor and Vice Chairman, Department of Urology, New York Medical College; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; J Stuart Wolf, Jr, MD, FACS, David A Bloom Professor of Urology, Director, Division of Minimally Invasive Urology, Department of Urology, University of Michigan Medical Center; Bradley Fields Schwartz, DO, FACS, Associate Professor of Urology, Director, Center for Laparoscopy and Endourology, Department of Surgery, Southern Illinois University School of Medicine Author and Editor Disclosure Synonyms and related keywords: augmentation cystoplasty, bladder augmentation, AC, enterocystoplasty, decreased bladder capacity, abnormal detrusor compliance, urinary urgency, urinary frequency, urinary incontinence, recurrent urinary tract infections, UTIs, pyelonephritis, progressive renal insufficiency, ileocystoplasty, sigmoid cystoplasty, gastrocystoplasty, ureterocystoplasty, autoaugmentation, detrusor myectomy, sacral neuromodulation INTRODUCTIONBladder augmentation, also called augmentation cystoplasty (AC), is a surgical procedure used in adults and children who lack adequate bladder capacity or detrusor compliance. Decreased bladder capacity or abnormal compliance may manifest as debilitating urgency, frequency, incontinence, recurrent urinary tract infections (UTIs), pyelonephritis, or progressive renal insufficiency. For many patients, augmentation cystoplasty can provide a safe functional reservoir that allows for urinary continence and prevention of upper tract deterioration. History of the ProcedureAugmentation cystoplasty with a segment of native tissue (usually an intestinal segment), was first performed in the late 1880s in animals and in the 1890s in humans. The original indication for the procedure was a small contracted bladder caused by tuberculous cystitis. Since that time, advances in surgical technique, perioperative care, and antibiotics have greatly improved outcomes. Because the augmented bladder typically empties poorly, the introduction of clean intermittent catheterization by Lapides et al in the early 1970s was pivotal in allowing the widespread use of augmentation cystoplasty.1 This allowed convenient, controlled bladder emptying of a safe, functional reservoir. In 2005, 162 augmentation cystoplasty procedures were logged among Medicare patients.EtiologyBoth neuropathic and non-neuropathic causes for severe bladder dysfunction exist in pediatric and adult populations. Neuropathic causes include the following:
Non-neuropathic causes include the following:
ClinicalDecreased bladder capacity or abnormal compliance may manifest as debilitating urgency, frequency, incontinence, recurrent UTIs, pyelonephritis, or progressive renal insufficiency. Various studies used to evaluate such symptoms may reveal severe dysfunction.
INDICATIONSAny 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 and anticholinergic medications. 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. Neurogenic bladder in the pediatric population is often associated with congenital anomalies, including the following:
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. RELEVANT ANATOMYSee Intraoperative details for a discussion of relevant anatomy. CONTRAINDICATIONSPatients who are unable or unwilling to perform life-long intermittent catheterization should not undergo augmentation cystoplasty because of the high likelihood of ultimately requiring catheterization. In addition, patients with inflammatory bowel disease (especially Crohn disease), 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 such as continued medical management or creation of a less complex, temporizing form of urinary drainage. WORKUPLab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
TREATMENTMedical therapyPrior to consideration for augmentation cystoplasty, patients should have timed voids as often as necessary to maintain low bladder volume and pressure. Anticholinergic medications (eg, oxybutynin, hyoscyamine, tolterodine): These medications 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 Ellsworth et al (2005) demonstrated in young children with neurogenic bladders.2 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. 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 measure fail, augmentation cystoplasty should be considered. Surgical therapyBladder-augmentation candidates may have 2 less-invasive surgical options prior to augmentation cystoplasty. These include cystoscopic injection of botulinum toxin A and sacral neuromodulation. Botulinum toxin A injections are used in some patients with overactive bladder and may benefit bladder-augmentation candidates. Some small studies have demonstrated significant increases in bladder volumes, often superior to those seen with oral medications.3, 4, 5 However, in patients with extremely reduced bladder compliance or volume, this treatment may not be adequate or durable. Furthermore, Schurch et al (2007) demonstrated that botulinum toxin injections improved quality-of-life scores in many patients with neurogenic incontinence despite oral anticholinergic therapy.6 Sacral neuromodulation (also known as sacral nerve stimulation [SNS]), is a minimally invasive technique that has markedly improvemed bladder volume, urge symptoms, and incontinence rates in patients with detrusor overactivity and urge urinary incontinence. The procedure can also help patients with urinary retention with high residual volumes after voiding. In the first stage of this procedure, 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 promise as a way to avert major surgery in adult and pediatric patients who would otherwise be candidates for augmentation cystoplasty. Long-term follow-up is limited, but this appears to be a durable option.7 When medical treatment, behavioral modifications, and other less-invasive options fail, formal surgical therapy with augmentation cystoplasty is warranted. Failure is defined as debilitating urinary symptoms (eg, frequency, urgency, incontinence) or bladder-storage pressures (ie, >40 cm H20) that risk damage to the renal parenchyma. Appropriately 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, also consider patient renal function, serum acid or base status, and the potential need for dialysis. One should 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.Preoperative detailsAdult 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. Other preoperative considerations include planning for concomitant procedures, selection of enteric segments to be used, and bowel preparation.
Selection of tissue for augmentation cystoplasty This section addresses the preoperative determination of optimal tissue for augmentation cystoplasty. Note that one should always be prepared to use alternatives to the planned augmenting segment if the patient's anatomy is unfavorable for the planned procedure.Proper selection of tissue segment begins with analyzing the patient’s anatomy and comorbidities but also requires consideration of intraoperative anatomic findings. Important preoperative considerations for the selection of tissue for augmentation cystoplasty include the following:
Table 1. Comparison of Tissues for Augmentation Cystoplasty Bowel preparation
Intraoperative detailsTwo different methods can be used to prepare the bladder: (1) A U-shaped flap can be lifted with its base anterior upon the bladder or (2) 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 (eg, in patients with interstitial cystitis) to prevent symptom recurrence, note that the bulk of the bladder can 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 as not to create a poorly draining diverticulum. General principles of using enteric segments
Ileocystoplasty
Sigmoid cystoplasty
Ileocecocystoplasty
Gastrocystoplasty
Ureterocystoplasty
Other options Autoaugmentation (also called detrusor myectomy): In this procedure, the serosa and muscular components of the bladder dome are incised or excised, allowing the mucosa of the bladder to protrude out. The mucosa may then be left alone or supported by a cover of omentum or demucosalized bowel. An autoaugment can increase bladder volume and improve detrusor compliance without using enteric segments, significantly decreasing surgical morbidity. Laparoscopic augmentation cystoplasty: This procedure is becoming increasingly common at many institutions. In performing laparoscopic augmentation cystoplasty, the primary goal 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.Postoperative detailsIntravenous fluids and nasogastric drainage are initially maintained for several days until the patient’s bowel function returns. Fluid and electrolyte status are monitored clinically with serum chemistry evaluation.
Follow-upThe patient should be seen for follow-up visits at 6 weeks, 3 months, 6 months, and yearly intervals. The focus is on preventing complications by monitoring with appropriate laboratory and radiologic studies.
COMPLICATIONSPerforation Approximately 6% of patients who undergo augmentation cystoplasty experience perforation.10 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 neurological impairments. Traditional or 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, and/or overdistention may be involved. Injury with self-catheterization may be responsible for some cases of perforation. Rivas et al (1996) 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).11 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 compositing; thus, treatment should be initiated immediately for bacteruria 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. No uniform recommendations currently exist 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 (1) extracorporeal shockwave lithotripsy, (2) endoscopic fragmentation or removal through urethra or catheterizable stoma, (3) percutaneous fragmentation or removal, and (4) 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 gastrocystoplasty, which causes hypokalemic hypochloremic metabolic alkalosis, most intestinal segments can cause metabolic acidosis. The jejunum, which is 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 for this has yet to be elucidated, but oral bicarbonate replacement may obviate some of these effects. In addition, patients with baseline renal insufficiency are at a significantly increased risk of developing 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 jejunum 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 the patients with renal insufficiency who have acidosis; however, severe metabolic derangements may still develop. Rink et al (1995) reported on episodes of severe hypokalemic hypochloremic metabolic alkalosis developing after gastrointestinal illness.12 Table 2. Metabolic Changes Caused By the Use of Various Tissues in Augmentation Cystoplasty
Hypercontractility and poor compliance are more common with the use of sigmoid bowel segments but can occur with any segment despite adequate detubularization of the segment. In some cases, this can lead to the need for reaugmentation. Hypocontractility of the augmented bladder with incomplete voiding is also a possibility that patients should understand before surgery. They must be physically and emotionally prepared to perform intermittent catheterization for life. Incontinence This can occur from using an enteric segment for augmentation that 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 augment, and urine may leak through a poorly constructed catheterizable stoma. UTI may also lead to detrusor instability and incontinence. Poor outlet resistance at the bladder neck and/or external sphincter will cause urine leakage if undiagnosed before surgery and addressed at the time of augmentation cystoplasty. Hematuria/dysuria syndrome The symptom complex of hematuria and/or dysuria occurs with voiding or catheterization in up to 33% of patients after augmentation gastrocystoplasty. Continence is particularly important in patients with gastrocystoplasty because of perineal and peristomal skin irritation that can occur owing to 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 re-augmentation using ileum. Malignancy Augmented bladders appear to be at an increased risk for malignancy. Adenocarcinoma is the most commonly observed tumor, and all segments seem to be equally at 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 (1990) recommend that patients with augmentation cystoplasty undergo yearly cytology and endoscopy and that patients undergo biopsy beginning 10 years after surgery.13 Some advocate general anesthesia during surveillance cystoscopy, as 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 removing the ileocecal valve from the intestinal tract in the augment construction. This is more likely in the pediatric patient with neurogenic bladder and intestinal dysfunction. Removal of the ileocecal valve may allow decreased transit time of stool or may allow retrograde colonization of the distal small intestine, with fat malabsorption in this segment. Increased bile salt delivery to the colon may cause secretory diarrhea. Other complications With removal of the terminal ileum from the alimentary tract, vitamin B-12 and bile salt reabsorption is compromised. 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. OUTCOME AND PROGNOSISIn properly selected patients, augmentation cystoplasty is an excellent procedure that provides a safe and effective way to improve 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 by early recognition and prompt therapy. Patient satisfaction Herschorn et al (1998) reported on an augmentation cystoplasty population using a survey to address patient complications and satisfaction.14 At a mean of 6 years after surgery, 41% of the patients had 1 or more complications, with 36% of all patients requiring intervention. Most took medications (ie, anticholinergics, antidiarrheals, antibiotics). Of 59 patients, 56 required clean intermittent catheterization at a mean interval of 4.6 hours, and 18% percent had postoperative bowel dysfunction versus 7% with preoperative dysfunction. FUTURE AND CONTROVERSIESRole of autoaugmentation McGuire's group compared patients treated with augmentation cystoplasty to patients treated with autoaugmentation.15 They stratified patients by etiology of bladder dysfunction and compared urodynamic and symptomatic improvement. They determined that autoaugmentation causes less morbidity, commonly reduces symptoms, and routinely improves bladder compliance; however, the gains in bladder capacity were much less than those seen with augmentation cystoplasty. 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. Laparoscopy and robotics Hedican et al (1999) used laparoscopy to mobilize the intestine in complex pediatric procedures, including augmentation cystoplasty.16 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 and/or for re-establishment of bowel continuity. Laparoscopic autoaugmentation has also been shown to be technically feasible. Braren and Bishop (1998) performed laparoscopic autoaugmentation in 7 pediatric female patients aged 3 months to 15 years.17 The operative times ranged from 55-93 minutes. Bladder capacity increased 55-95%, all had symptom improvement, and 6 of 7 were completely dry. 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. These procedures may reduce morbidity, reduce intra-abdominal adhesions, and improve body self-image. Alternative tissue sources Desai et al (2003) used ureteral tissue balloon expanders prior to laparoscopic bladder augmentation in a porcine model. In addition, basic science researchers continue to investigate the possibility of using alternatives to autologous tissues for augmentation cystoplasty. Small-intestine submucosa and synthetic polymeric substances continue to be investigated. Tissue-engineering efforts continue, although many challenges exist in reproducing the elastic and contractile properties of the bladder. A newer type of tissue engineering with nano-structured polymeric scaffolds appears to offer promising direction. The use of any such surfaces could expand bladder volume and decrease bladder compliance without the morbidity and potential complications of intestinal harvest. Potential benefits would include decreases in complications, operative time, metabolic derangements, and deleterious effects on bowel function. FURTHER READINGFor additional information, see Medscape’s Urinary Incontinence & OAB Resource Center. MULTIMEDIA
REFERENCES
| ||||||||||||||||||||||||||||||||||||||||||||||