Myelomeningocele (spina bifida): Urinary tract complications

INTRODUCTION — Nearly all patients with myelomeningocele have bladder dysfunction (neurogenic bladder). This may adversely affect urinary continence and quality of life and can also lead to progressive deterioration of the upper urinary tract and chronic renal disease. Thirty to 40 percent of children with myelomeningocele develop some degree of renal dysfunction [1]. Treatment to reduce bladder pressures and minimize urine stasis often prevents or attenuates this complication.

The assessment and management of the urinary tract complications of spina bifida are discussed here. Other aspects of myelomeningocele are discussed separately. (See "Myelomeningocele (spina bifida): Anatomy, clinical manifestations, and complications" and "Myelomeningocele (spina bifida): Management and outcome".)

PATHOPHYSIOLOGY — Patients with myelomeningocele have problems with storage and/or emptying of urine because the spinal cord lesion disrupts nervous system control of urinary voiding mechanisms (figure 1). The results in urinary incontinence, increased risk of urinary tract infection, and risk of renal injury. The abnormalities of lower urinary tract dynamics include:

●Flaccid bladder

●High pressure bladder

●Hyperreflexic bladder

●Open bladder neck and/or overactive external/internal sphincter

●Lack of coordination between the bladder and the external sphincter during voiding and/or bladder filling (detrusor sphincter dyssynergia)

Neither the location of the spinal lesion nor the neurologic examination are sufficient to predict the type or severity of urinary tract dysfunction, because the spinal cord level at which the bladder is controlled is below the spinal roots directing lower extremity function [2]. As an example, patients with very "low" level (sacral) myelomeningocele may have unfavorable bladder dynamics even if lower extremity function is normal. Therefore, all patients with spina bifida, including those who are ambulatory, should be evaluated periodically with ultrasonography and urodynamic studies, as described below. (See "Etiology and clinical features of bladder dysfunction in children", section on 'Normal voiding'.)

Patients with myelomeningocele also have increased risk for developing urinary tract stones. In one study, the prevalence of kidney stones was 4 percent among children with spinal dysraphism, compared with 0.2 percent in healthy children [3]. Likely mechanisms for this predisposition to upper tract urolithiasis include immobility (with resultant bone resorption), bacteriuria, and urinary stasis.

ASSESSMENT

Initial evaluation — Most patients with myelomeningocele are diagnosed as newborns. For these patients, an ultrasound of the kidneys and bladder should be performed shortly after birth. This study detects the presence of hydronephrosis or hydroureter, and assesses bladder wall thickness and distension [4-6]. The ultrasound should be performed after the newborn physiologic intravascular volume depletion has resolved (three days after birth).

In the first months of life, and normally at three months of life to allow for any temporary changes that occurred after back closure to resolve, the function of the neurogenic bladder should be evaluated with the following studies, ideally performed at the same time, in the form of a video-urodynamic study:

●Voiding cystourethrogram (VCUG), which will rule out or document vesicoureteral reflux (VUR), assess the bladder wall (smooth versus trabeculated), bladder capacity, and post void residual (image 1).

●Cystometrogram (CMG) and electromyogram (EMG) (urodynamic studies), which measure bladder pressures during filling and voiding, evaluate for uninhibited contractions, and assess the function of the bladder neck and external sphincter during filling and voiding (figure 2) [4-6].

A normal bladder will be smooth walled, without VUR, without uninhibited contractions, fill and empty at low pressure, and upon voiding exhibit coordination of the bladder, contracting with pelvic floor relaxation. A neurogenic bladder may exhibit problems with any or all of these normal bladder functions. (See "Evaluation and diagnosis of bladder dysfunction in children", section on 'Urodynamic testing'.)

The same evaluation should be performed in patients who present after the newborn period.

Monitoring — Patients with myelomeningocele should be evaluated with renal and bladder ultrasounds and urologic studies periodically throughout life (table 1). These studies monitor for changes in urinary tract function and anatomy, and guide treatment decisions. Urinary tract changes may occur for any of the following reasons:

●Bladder function may change within the first few months of life, probably because of healing after the initial spine closure at birth [5].

●The capacity of a neurogenic bladder may not grow as the child grows, as normal bladders do. As an example, an infant bladder that accommodates 75 cc of urine might be sufficient for an infant but not for a five year old who requires twice that capacity.

●Lower urinary tract function can change during childhood due to development of a tethered spinal cord [7]. Surgical release of a tethered cord can be successful in improving urologic function and will prevent further neurologic sequelae [8,9]. (See "Myelomeningocele (spina bifida): Management and outcome", section on 'Tethered cord'.)

●The child's adherence to a regimen of intermittent catheterization and medication may vary.

●As the child grows, doses of medications and size of catheters need to increase.

Ultrasound — After the baseline evaluation at birth, the kidney and bladder ultrasound should be repeated at three to four months of age (table 1), after the recovery from the back surgery is complete and postsurgical swelling has subsided. The findings of hydronephrosis, hydroureter, abnormal bladder wall thickness, or excessive post-void residual volume suggest abnormal voiding mechanics and a risk for chronic kidney disease. The study should then be repeated every three months in the first year of life, every six months in the second year, and then every year thereafter. The ultrasound should be performed more frequently if clinical symptoms such as urinary tract infection (UTI) occur, the patient undergoes other neurosurgical or spinal surgery (eg, tethered cord release or spinal fusion), noncompliance with clean intermittent catheterization is suspected, or in the setting of a particularly high risk bladder. Some practices begin to see patients every six months again in adolescence as it is a high risk-time for noncompliance. (See "Evaluation and diagnosis of bladder dysfunction in children", section on 'Ultrasonography'.)

Voiding cystourethrogram, cystometrogram, and electromyogram (video-urodynamics) — A VCUG (image 1), CT (computed tomographic) metrogram (CMG) (image 2A-B), and EMG (figure 2) are recommended during the first four to six months of life, at age one year, at approximately age three to four years (because this is a typical time for toilet training), and every two to three years thereafter (table 1) [7,10].

In addition, because changes in lower urinary tract function may be the first sign of spinal cord tethering, urinary tract function utilizing these video-urodynamic studies should be reevaluated if there is a change in urinary continence, new ultrasound findings such as hydronephrosis, or recurrent UTIs. In addition, urodynamic studies may be repeated to assess the effectiveness of an intervention, such as medication, or if there is question of other neurogenic changes, such as changes in lower extremity function. (See "Evaluation and diagnosis of bladder dysfunction in children", section on 'Urodynamic testing'.)

Other studies — Urinalysis and urine culture should be performed only if there are symptoms of a UTI. (See 'Urinary tract infections' below.)

Baseline blood work for kidney function (blood urea nitrogen and creatinine) should be performed in infancy and every few years thereafter [5]. If there are recurrent UTIs or significant bilateral hydronephrosis, it should be done more often.

We perform renal scans (using DMSA or MAG3) as a baseline study in patients with significant abnormalities of the upper tract on the ultrasound or those with unfavorable urodynamics. These scans also may be helpful in patients with recurrent UTIs to assess for scarring of the kidneys [11]. (See "Evaluation of congenital anomalies of the kidney and urinary tract (CAKUT)", section on 'Static renal scan'.)

Bowel assessment should be made at the same intervals as the ultrasound, assessing for signs and symptoms of stool retention and incontinence. (See "Myelomeningocele (spina bifida): Management and outcome", section on 'Bowel management'.)

MEDICAL MANAGEMENT — The goals for management of neurogenic bladder in patients with myelomeningocele are to preserve kidney function and for the patient to have independent continence of bowel and bladder at a developmentally appropriate age [12].

Management is based on ultrasound findings, symptoms, and urodynamic findings, as well as psychosocial assessment of readiness. Clean intermittent catheterization (CIC) is recommended for all patients with neurogenic bladder. Anticholinergic agents are added for patients with high pressure bladders or hyperreflexic bladders. For patients with vesicoureteral reflux (VUR), anticholinergics are also used, and in some cases prophylactic antibiotics are added.

A variety of surgical approaches may be helpful for patients who fail medical treatment for neurogenic bladder or to facilitate self-management and continence. (See 'Surgical management' below.)

Clean intermittent catheterization — We suggest early initiation (eg, shortly after birth) of CIC (picture 1) for all infants with neurogenic bladder [5]. The goal of CIC is to reduce the risk of urinary tract infection (UTI) and overdistension of the bladder, which can lead to hydronephrosis, VUR, and chronic kidney disease.

There are several important reasons for early initiation of CIC:

●Early initiation of CIC may improve outcomes as compared with later initiation of CIC. In a case series reporting outcomes after at least 11 years of CIC, initiating CIC early (<1 year old) was associated with less deterioration of the urinary tract as compared with late treatment initiation (>3 years old) [13]. Other observational studies suggest similar benefits from early initiation of CIC, and some suggest that there is additional advantage to initiating treatment during the first three months of life [14-16]. Consistent use of CIC regimens has reduced the need for bladder augmentation [5].

●Most affected individuals will eventually require CIC to attain continence or protect the kidneys, and it is easier to start a CIC program in infancy. Children who were started on CIC as infants appear to tolerate and be more compliant with the CIC than children who begin at a later age. It is more difficult to start a CIC program on a five year old than a child that has previously been catheterized. Most children can perform CIC independently by five years of age if initiated during infancy.

●Clean intermittent self-catheterization has very few complications. In a study of 31 females followed to 10 to 19 years of CIC (with or without anticholinergic treatment), only minor complications were seen. These were least likely to occur when catheters size 12 French or larger were used, and when self-catheterization was performed instead of assisted catheterization [17]. Complication rates were also low in boys [18].

Some patients will continue to have urinary tract deterioration despite an optimal regimen of CIC and anticholinergic medications. In this case, nocturnal bladder emptying can be helpful. This is achieved by using a continuously draining catheter during sleep or through scheduled nighttime CIC. Among 19 children treated with nocturnal bladder emptying, 15 had clinical benefit (decrease in hydronephrosis, fewer UTIs, increase in bladder capacity, or improved urinary continence) [19,20]. If nocturnal bladder emptying is unsuccessful, augmentation cystoplasty may be needed in order to achieve continence and/or preserve kidney function. (See 'Bladder augmentation' below.)

Anticholinergics — Anticholinergic medication is appropriate for patients with myelomeningocele who have high pressure bladders, hyperreflexic bladders, and/or VUR. In these patients, VUR is secondary in nature because it is caused by the intravesicular pressure of the neurogenic bladder. The management of secondary VUR differs from that of primary VUR, which occurs in a patient without neurogenic bladder. (See "Clinical presentation, diagnosis, and course of primary vesicoureteral reflux".)

Patients with secondary VUR should be treated with an anticholinergic agent to lower filling pressures, CIC to prevent overfill, and, in rare cases, prophylactic antibiotics to prevent infection [10,21]. The efficacy of this regimen was demonstrated in a sequential nonrandomized study, in which patients with neurogenic bladder were treated with CIC and oxybutynin [21]. During five years of follow-up, the upper urinary tract deteriorated less often in the treated group as compared with historical controls (8 versus 48 percent). Similar results were noted in a case series of 144 children with myelomeningocele, in which only 3 percent of children treated with early initiation of CIC and anticholinergics had kidney scarring or partial loss of kidney function [15]. This compares favorably to the high rates of renal parenchymal damage reported in older series in which children were managed less aggressively [22,23]. In one such series, 13 percent of children developed cortical damage by age 2 years and 27 percent by age 10 [22]. Of note, in the case series of 144 children described above, delays in initiating a regimen of CIC and anticholinergic therapy (eg, due to unrecognized spina bifida) were associated with higher rates of kidney scarring.

For an anticholinergic agent, we typically use oxybutynin at the following doses:

●Infants <12 months of age – 0.1 mg/kg orally three times a day (available as Ditropan syrup [brand name], 1 mg/mL)

●Children one to five years of age – 0.2 mg/kg per dose three times a day (or 1 mg per year of age per dose)

●Children ≥5 years old – We use oxybutynin tablets (Ditropan [brand name]), 5 mg orally three times a day

For children ≥5 years old, the extended release preparation (Ditropan XL [brand name]) may be used, beginning with 5 mg daily and titrated to effect (to a maximum dose of 20 mg daily). Ditropan is also available as a transdermal patch and as a gel. An alternative anticholinergic agent is tolterodine (Detrol [brand name]) in a dose of 1 to 2 mg by mouth twice daily or the long-acting preparation (Detrol LA [brand name]), 2 to 4 mg by mouth once daily.

In June 2021, fesoterodine fumarate, another extended-release anticholinergic drug, was approved by the US Food and Drug Administration to treat children with neurogenic detrusor overactivity in children ages ≥6 years of age with a weight greater than 25 kg [24]. The approval was based on an open-label clinical trial in children between 6 and 17 years of age with neurogenic detrusor overactivity [25].

Other agents — Alternative agents have been developed based on the poor tolerability and limited efficacy of anticholinergic medications.

●In March 2021, mirabegron, a beta adrenergic agonist, was approved by the FDA to treat children with neurogenic detrusor overactivity in children ages three years and older [26]. The approval was based on improved bladder function in a study of 86 patients between 3 and 17 years of age.

●Other alternative agents (including solifenacin, trospium chloride, darifenacin, and propiverine) have generally not been studied in children, and the studies in adult patients were primarily for treatment of overactive bladder rather than neurogenic bladder [27].

Botulinum toxin — Botulinum toxin type A injection (onabotulinumtoxinA) has been shown to reduce bladder pressures in the neurogenic bladder [28,29]. However, not all patients with myelomeningocele have a meaningful clinical response to botulinum toxin treatment [29]. For those that do respond, the response is generally not long lasting, and treatments must be repeated to maintain response. In one study, the mean duration of response was 15 months (range 3 to 42 months) [28]. Patients with poorly compliant bladders are less likely to respond [28,29]. Another disadvantage of botulinum toxin treatment is that it requires a general anesthetic in children.

Thus, botulinum toxin treatment may be a reasonable alternative to bladder augmentation, especially for patients with more compliant bladders. It can also be useful in the situation where there is a very young, small, or fragile child who has a very high pressure bladder but would not tolerate the invasive augmentation surgery. Botulinum toxin can be used to postpone the augment a year or two while the child grows and/or becomes more healthy and able to tolerate augmentation.

Urinary tract infections — UTIs are a common concern in individuals who perform CIC. Most patients have bacterial colonization of the urinary tract, and abnormalities are often found on urinalysis and urine culture. Approximately 70 percent of patients performing CIC have bacteriuria, but most are asymptomatic and do not require treatment [30-32]. Urinalysis and urine culture should only be performed, and positive results subsequently treated, in symptomatic patients. Simple cloudy or smelly urine can usually be treated with increasing fluids and increasing the interval of CIC to every 1 to 2 hours for 12 hours.

Symptoms suggesting UTI include pain with CIC, gross hematuria, back or abdominal pain, lethargy, fever, and/or vomiting. Patients with these symptoms should be evaluated with a urine culture and treated as indicated. A careful neurologic assessment should also be performed because a ventriculoperitoneal shunt malfunction or infection can mimic symptoms of a UTI. (See "Infections of cerebrospinal fluid shunts", section on 'Clinical manifestations' and "Hydrocephalus in children: Management and prognosis", section on 'Shunt complications'.)

Treatment for symptomatic UTI in patients with myelomeningocele is generally similar to that for other children with UTI, with the exception that children undergoing CIC are at increased risk of infection with resistant organisms [32]. Empiric therapy while awaiting urine culture results can be guided by previous culture results and susceptibilities, if available. When urine culture results from the current episode are available, antibiotic therapy can be tailored according to susceptibilities of the identified uropathogen. (See "Acute infectious cystitis: Management and prognosis in children older than two years and adolescents", section on 'Complicated cystitis'.)

In addition to treating the UTI, a thorough history should be obtained to assess for cause of the infection. If warranted by the history, an ultrasound and/or urodynamic evaluation should be performed. Possible triggers for a UTI are noncompliance with the treatment regimen, constipation, a change in bladder dynamics (which may be caused by spinal cord tethering), or a need for adjustment of a treatment regimen.

Prophylactic antibiotics — We do not routinely administer prophylactic antibiotics in patients with myelomeningocele who are on CIC, including patients with VUR. The use of prophylactic antibiotics was intended primarily to prevent UTIs in patients with myelomeningoceles, but evidence of their benefit is lacking. Our approach to prevention of UTIs focuses on assuring efficient bladder emptying by CIC, maintenance of safe bladder pressures with anticholinergic medication and intravesical botulism toxin injections, and nighttime catheter drainage as indicated by urodynamic studies.

This approach is supported by a prospective multicenter study of 299 newborns with myelomeningocele [33]. In this cohort, a standardized management protocol was followed that included timing and use of testing (eg, ultrasound and urodynamics) and interventions (eg, CIC, anticholinergic therapy, no prophylactic antibiotics) [34]. In the first four months of life, only 12 patients (4 percent) had symptomatic culture-proven UTI (defined by study protocol), although 23 patients had positive cultures and 48 patients (16 percent) were treated for UTI. The presence of higher degrees of hydronephrosis (grades 3 and 4) as well as clean intermittent catheterization increased the risk of symptomatic culture-proven UTI. The authors concluded the risk of culture-positive symptomatic UTI was low, and routine prophylactic antibiotics in young infants with myelomeningocele may not be necessary.

Latex precautions — Patients with myelomeningocele are at risk of developing latex allergies if they are repeatedly exposed to latex during intermittent catheterization or surgical procedures. Therefore, we recommend that latex exposure should be avoided throughout life by instituting "latex precautions" from birth. (See "Myelomeningocele (spina bifida): Management and outcome".)

Bowel management — Most individuals with neurogenic bladder also have neurogenic bowel, causing slow motility and/or laxity of the anal sphincter, with associated constipation and/or incontinence. The goal of a continence program for neurogenic bowel is to prevent constipation and achieve timed elimination of stool through the use of oral laxatives, suppositories, enemas, and advanced bowel management options (eg, transanal irrigation systems, antegrade continence enema), which may be used singly or in combination. Bowel management is discussed in greater detail separately. (See "Myelomeningocele (spina bifida): Management and outcome", section on 'Bowel management'.)

SURGICAL MANAGEMENT — Several surgical procedures are used to manage neurogenic bladder in patients with myelomeningocele; these are directed at preventing kidney complications, promoting continence, and facilitating self-catheterization.

Fetal intervention — In utero repair of myelomeningocele is performed in specialized centers. Bladder dysfunction following fetal surgery is common [35-42]. It is uncertain whether the rate of bladder dysfunction is lower in children who undergo fetal repair compared with those who undergo postnatal repair. If there is an improvement, it does not appear to be dramatic and therefore urologic outcomes alone should not be the sole impetus to perform in utero closure of myelomeningocele.

Urologic outcomes following fetal surgery are best characterized in reports of the long-term follow-up of children enrolled in a randomized trial comparing fetal surgery and postnatal surgery for repair of myelomeningocele [38,40]. By school age, more children in the fetal surgery group reported voiding volitionally compared with the postnatal surgery group (24 versus 4 percent) and fewer children in the fetal surgery group required clean intermittent catheterization (CIC; 62 versus 87 percent). Rates of bladder augmentation, vesicostomy, and urethral dilation were similar in the two groups. In other single-center case series, urinary tract function in patients who underwent fetal surgery appeared to be similar to that of children who underwent postnatal repair [35-37,39,41].

Fetal surgery for myelomeningocele is discussed in greater detail separately. (See "Myelomeningocele (spina bifida): Management and outcome", section on 'Fetal surgery'.)

Bladder augmentation

Indications and procedures — Bladder augmentation is performed in individuals who, despite CIC and anticholinergic medications, continue to have very high bladder pressures and need a larger bladder capacity to reduce this pressure, and thus preserve their kidney function. Bladder augmentation also may be beneficial for patients with severe incontinence that is refractory to medical management. Both enteric bladder augmentation and bladder auto-augmentation have been used in this setting; however, there is greater experience with enteric bladder augmentation.

Enteric bladder augmentation — Enteric bladder augmentation, also known as enterocystoplasty, is a procedure in which a detubularized segment of intestine (usually ileum) is added to the bladder to increase capacity and lower pressure (figure 3). In the past, gastric segments were used. However, these gastric-derived patches tended to cause problems with the gastric acid secretion (hematuria and dysuria) [43].

Potential complications and consequences of enteric bladder augmentation include the following:

●Bladder perforation – Perforation of an augmented bladder can be a lethal consequence of bladder augmentation. Patients can present with peritonitis, which is especially dangerous for patients with ventriculoperitoneal (VP) shunts, as the shunt may also become infected. Adolescent patients with bladder augmentation are at the highest risk for bladder perforation, especially if they are not compliant with clean intermittent catheterization.

Signs and symptoms of augmented bladder perforation include abdominal pain, fever, and decreased urine output. A strong index of clinical suspicion is needed, as the initial evaluation may not identify that the source of infection is due to leakage or urine from a perforation of the augmented bladder.

The diagnosis of bladder perforation is made by computed topography (CT) cystogram with contrast that demonstrates leakage of contrast outside the reconstructed bladder and can also define whether the perforation is extraperitoneal or intraperitoneal (image 2B).

Extraperitoneal bladder rupture can often be managed by bladder drainage with catheters, whereas intraperitoneal bladder rupture typically requires operative repair of the perforation [44-46].

●Vitamin B12 deficiency – Patients who have undergone enteric bladder augmentation surgery have an increased risk of vitamin B12 deficiency [47]. Thus, for patients who are five or more years beyond bladder augmentation, we suggest laboratory evaluation with hemoglobin level and, if anemia is detected, measurement of B12 levels. (See "Clinical manifestations and diagnosis of vitamin B12 and folate deficiency".)

●Electrolyte disturbances – Introducing intestine into the urinary tract can result in hyperchloremic metabolic acidosis, and consequently these patients should have a renal blood profile performed once a year.

●Bladder calculi – Bladder calculi are common after bladder augmentation [31,47]. The problem is likely due to excessive mucus in the urine, chronic bacterial colonization, and/or underlying metabolic abnormalities. Routine bladder irrigations can help clear excessive mucous and may prevent bladder calculi; however, patients who have developed a bladder stone tend to have recurrences even with routine irrigation [47].

●Other complications – Other complications include small bowel obstruction, fecal incontinence, and bladder stone (figure 4) [31,47].

●Risk of malignancy – There have been a few documented cases of cancer in the augmented bladder, occurring many years after the surgery [48,49]. However, it is uncertain whether routine cancer surveillance (eg, with annual cystoscopy) is warranted in these patients given the low incidence of malignancy and unproven benefit of screening [50]. In our practice, we begin surveillance 10 years after bladder augmentation. Surveillance consists of an annual abdominal ultrasound and basic metabolic, renal, and hematologic laboratory tests, without routine surveillance cystoscopy.

Bladder auto-augmentation — Another approach to bladder augmentation that has been attempted is a bladder auto-augmentation, wherein part of the musculature of the bladder wall is removed. Case series of auto-augmentation in this patient population have reported contradictory results. One series reported good long-term outcomes, with improvements in vesicoureteral reflux and continence in most patients (median follow-up of 6.8 years) [43]. By contrast, another series with similar length of follow-up described ongoing incontinence and deterioration of the upper urinary tract in most patients undergoing the procedure [51]. It is possible that individual patient characteristics, such as a higher baseline bladder capacity, predict better outcomes of auto-augmentation. Auto-augmentation may delay the need for intestinal augmentation for many years, thereby preventing short-term complications of intestinal augmentation.

Bladder neck/outlet surgery — If the bladder outlet is weak, outlet/bladder neck surgery can be performed to add resistance and gain urinary continence. There are various types of bladder neck/outlet surgery, including endoscopic bulking agents, artificial urinary sphincters, and bladder neck slings, and the choice depends on individual characteristics (particularly sex) of the patient. Most surgeons begin with endoscopic bulking agents for less severe incontinence followed by bladder neck sling in females because of the long-term negative sequela associated with artificial urinary sphincters.

Continent catheterizable stoma surgery — A patient who is unable to catheterize their own urethra may benefit from a continent abdominal catheterizable channel such as an appendicovesicostomy (Mitrofanoff procedure) or ileovesicostomy (Monti procedure). The channel is constructed between the bladder and the skin utilizing appendix or bowel, with the stoma placed at the level of the umbilicus or on the lower abdomen [52,53]. This location is more accessible than the urethra, and reduces the time required for CIC, especially in females with lesions at the thoracic level. The most common complication is stenosis or leaking of the stoma at the skin, which may require dilation or surgical revision.

Ureteral reimplantation — This procedure is rarely necessary. It is occasionally used in selected patients with persistent reflux and upper tract deterioration, or in those with recurrent urinary tract infections despite an optimal regimen of CIC, anticholinergics, and prophylactic antibiotics [30].

Ureteral implantation should be considered cautiously for patients with neurogenic bladder. In these patients, the reflux is often caused by increased bladder pressures rather than by incompetent or inadequate closure of the ureterovesical junction. It is important to optimize medical treatment for the neurogenic bladder before considering ureteral reimplantation.

Vesicostomy — A vesicostomy is an incontinent diversion of the bladder to the lower abdominal wall (picture 2). Vesicostomy is rarely indicated in this patient population. This procedure is performed for bladder drainage in infants with high bladder pressure who have failed a regimen of CIC and anticholinergic medication [54]. The failure may be caused by poor adherence to the medical regimen or by a particularly small bladder capacity. Vesicostomy is usually used for temporary diversion until the patient or family/caregiver is able to adhere to the regimen or until the child is old enough to undergo bladder augmentation [55,56].

Neurosurgery — If an affected individual develops a tethered spinal cord, then neurosurgical intervention is warranted to preserve baseline urologic function and prevent further neurologic deterioration. (See "Myelomeningocele (spina bifida): Management and outcome", section on 'Tethered cord'.)

It is uncertain whether other neurosurgical techniques, such as the lumbar sacral nerve rerouting (Xiao procedure), improve bladder function. Based on the available evidence, the Xiao procedure is not recommended. The lumbar sacral nerve rerouting procedure is a surgical technique in which the neurologic defect is bypassed by creating a microanastomosis of the fifth lumbar ventral root to the third sacral ventral root. The initial report of this procedure in 20 children with myelomeningocele suggested that it improved or restored bladder control in the majority of patients [57]. A subsequent pilot study of the Xiao procedure in 13 patients treated in the United States demonstrated some transient improvement, albeit less impressive than the original report [58]. However, these results were not confirmed in subsequent observational studies in patients with spinal cord injury [59-61]. In addition, there were reports of complications, such as foot drop. In a randomized controlled trial in 20 children with myelomeningocele or lipomyelomeningocele, the Xiao procedure did not result in voluntary voiding or continence in any patient [62,63].

PROGNOSIS — With good urologic management, preservation of kidney function and, if desired, urinary continence prior to school entry are attainable goals.

Most patients with myelomeningocele will not be able to void normally and will require lifelong treatment with clean intermittent catheterization, medication, and/or surgery to be continent of urine and to protect the upper urinary tract [5].

Thirty to 40 percent of children with myelomeningocele develop some degree of kidney dysfunction [1]. Lack of coordination between the detrusor and external sphincter seems to be an important predictor of urinary tract deterioration, presumably because this condition promotes vesicoureteral reflux and high pressures to the kidneys. In a series of 36 infants with myelomeningocele, 50 percent of infants had discoordination of the detrusor and external urethral sphincter, 25 percent had synergic activity of the sphincter, and 25 percent had absent sphincter activity [10]. Thirteen of the 18 infants with discoordination of the detrusor-external sphincter developed hydroureteronephrosis (72 percent), compared with two of nine with synergy and one of nine with no sphincter activity.

Adults with myelomeningocele are at risk for depression, anxiety, and social isolation compared with the general population, and these psychosocial problems are also associated with lower urinary tract dysfunction [64].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Urinary incontinence in children" and "Society guideline links: Congenital malformations of the central nervous system".)

SUMMARY AND RECOMMENDATIONS

●Nearly all patients with myelomeningocele have bladder dysfunction (neurogenic bladder). This can cause incontinence or urinary stasis, with recurrent urinary tract infections (UTIs) and progressive deterioration of the upper urinary tract. (See 'Introduction' above and 'Pathophysiology' above.)

●Patients with myelomeningocele should be evaluated with kidney and bladder ultrasounds, voiding cystourethrograms, cystometrograms, and electromyograms periodically throughout life (table 1). These studies monitor for changes in urinary tract function and anatomy, and inform treatment decisions. Urinary tract changes may occur with growth, changes in responsiveness or adherence to treatment, or development of a tethered cord. (See 'Monitoring' above.)

●Medical management of neurogenic bladder in patients with myelomeningocele includes the following (see 'Medical management' above):

•For all patients with neurogenic bladder, we suggest early institution (ie, shortly after birth) of a regular regimen of clean intermittent catheterization (CIC) rather than waiting until later in childhood (Grade 2C). Beginning this regimen shortly after birth habituates the child to the procedure and may prevent urinary tract deterioration. (See 'Clean intermittent catheterization' above.)

•For patients with high intravesicular pressure and resultant vesicoureteral reflux (VUR), we suggest treatment with an anticholinergic agent in addition to CIC rather than CIC alone (Grade 2C). (See 'Anticholinergics' above.)

•Patients with myelomeningocele who develop symptomatic UTI are treated similar to other children with UTI, with the exception that children undergoing CIC are at increased risk of infection with resistant organisms. Empiric therapy while awaiting urine culture results can be guided by previous culture results and susceptibilities, if available. When urine culture results from the current episode are available, antibiotic therapy can be tailored according to susceptibilities of the identified uropathogen. (See 'Urinary tract infections' above and "Acute infectious cystitis: Management and prognosis in children older than two years and adolescents", section on 'Complicated cystitis'.)

•To prevent UTIs in patients with myelomeningocele, we suggest against routinely administering prophylactic antibiotics (Grade 2C). The risk of UTI is low if patients are effectively managed for efficient bladder emptying with CIC and anticholinergic agents, and as a result, prophylactic antibiotics are not necessary. (See 'Prophylactic antibiotics' above.)

●Several surgical procedures are used to manage neurogenic bladder in patients with myelomeningocele; these are directed at preventing kidney complications, promoting continence, and facilitating self-catheterization. (See 'Surgical management' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Angelique Champeau, CPNP, who contributed to an earlier version of this topic review.