eMedicine Specialties > Pediatrics: Surgery > Urology

Myelodysplasia and Neurogenic Bladder Dysfunction: Treatment & Medication

Author: Terry F Favazza, MD, Consulting Staff, Urologic Associates of Southern Arizona
Coauthor(s): Harry P Koo, MD, Chairman of Urology Division and Director of Pediatric Urology, Virginia Commonwealth University; Professor of Surgery, VCU School of Medicine, Medical College of Virginia; Director of Urology, Children's Hospital of Richmond
Contributor Information and Disclosures

Updated: Mar 27, 2008

Treatment

Medical Care

Medical care of children with myelodysplasia who have a neurogenic bladder requires constant vigilance and adaptation to new problems. Therapy is based on a few basic goals: to ensure safe intravesical pressures, to prevent urinary stasis and UTIs, and to promote urinary continence. The ultimate goal of medical therapy is to preserve renal function. In older children, medication may help maintain continence.

• Infection
  • UTIs are common in children with myelodysplasia. In the absence of reflux, patients with UTIs are treated symptomatically.
  • Patients with vesicoureteral reflux are often placed on prophylactic antibiotics to reduce the chance of upper UTI or pyelonephritis.
  • Bacteriuria is seen in as many as 55% of individuals who have received clean intermittent catheterization (CIC). Patients who are completley asymptomatic do not need treatment.
• Reflux
  • Reflux occurs in 3-5% of infants with myelodysplasia and is usually associated with detrusor hyperreflexia or DSD.
  • Treatment consists of antibiotic prophylaxis to prevent infection, anticholinergic medications to lower detrusor filling and voiding pressures, and a method of bladder emptying, most commonly IC. In children with lower-grade reflux who empty their bladders completely, treatment may be limited to prophylactic antibiotics. In children with high-grade reflux, IC is started to ensure complete emptying.
  • Children unable to empty their bladders, regardless of reflux, are treated with CIC.
  • Children with detrusor hyperreflexia (with or without hydronephrosis) are started on anticholinergic therapy to decrease intravesical pressures and possibly decompress the upper GU tracts. Reflux treated in this manner has shown a dramatic response, resolving in 30-55% of children.
  • Avoid the Crede maneuver (voiding by suprapubic pressure) in children with reflux because it can increase pressures and aggravate the degree of reflux.
• Intermittent catheterization
  • Because most patients with myelodysplasia are unable to spontaneously empty their bladders, numerous methods have been devised to potentiate bladder emptying. Initially, large numbers of patients underwent urinary diversion; however, frequency of renal failure was substantial. This changed dramatically with the introduction of CIC.
  • Bladder catheterization on a regular basis is a safe, effective method of emptying the bladder and, if performed under clean conditions, does not appear to significantly increase the risk of infection. More than any single concept, the practice of CIC has changed the treatment of and approaches to patients with neurogenic bladders.³
  • Currently, urinary diversion is rarely performed in pediatric patients.
• Continence
  • Although not an issue in infancy, continence becomes more important as patients age. When children reach school age and social interactions increase, managing incontinence becomes more of a priority.
  • Medical therapy consists of anticholinergic medications to increase the functional bladder volume and to reduce involuntary contractions. Additionally, alpha agonists have been used infrequently in children to increase sphincter tone at the bladder neck.
• Bowel function
  • Often, children with myelodysplasia have disturbances of bowel as well as urinary function. This is managed most commonly with mild laxatives, such as mineral oil, combined with enemas or digital stimulation to facilitate removal of bowel contents.
  • Constipation can affect bladder emptying adversely via a mechanism not yet fully understood but likely related to altered tone of the pelvic floor musculature or the physical compression of hard stool distorting the geometry of the bladder. The need for a program to combat constipation by maintaining soft stools and facilitating complete evacuation of bowel contents is an integral part of treatment in children with myelodysplasia.

Surgical Care

Surgery for neurogenic bladder, although once performed on most patients, is now primarily reserved for patients who have progressive renal damage despite maximal medical therapy or for patients with a noncompliant bladder. Most procedures are designed to allow adequate low-pressure bladder storage (thereby protecting the upper GU tract), to correct persistent reflux and prevent renal scarring, or to aid with continence. Experimental intrauterine fetal surgery performed to limit future morbidity is under investigation at some centers.^4,5,6,7

• Intrauterine surgery
  • Studies of surgically created neural tube defects in rats demonstrate that the exposed tissue in the myelomeningocele sustains secondary injury from mechanical and chemical factors during its prolonged exposure to the uterine environment. This has led to research on the effects of in utero closure of the defect.
  • Although considered experimental because of the limited numbers performed, preliminary findings appear to indicate that intrauterine closure can be accomplished with minimal morbidity to the fetus and the mother and that it may decrease the need for VP shunting later in life.
  • Whether in utero repair improves the neurologic outcome in these patients remains unclear.
• Ureteral reimplantation
  • Uretal reimplantation can be performed in patients with recurrent symptomatic UTIs despite adequate bladder drainage and antibiotic prophylaxis or in patients with persistent high-grade reflux with demonstrated renal scarring.
  • The purpose of the procedure is to create a nonrefluxing connection between the ureter and the bladder.
  • Most often, the procedure is performed by tunneling the ureter beneath the detrusor muscle.
  • This treatment is very effective, provided that a regimen is implemented to ensure a low-pressure reservoir and bladder emptying.
• Vesicostomy
  • In infants who cannot be catheterized or who demonstrate worsening renal function despite medical therapy and IC, cutaneous vesicostomy can be performed to establish adequate bladder drainage.
  • The bladder is brought out to the skin, and urine drains continually into a diaper.
  • Vesicostomy is an effective temporary procedure that may be reversed at any time.
• Bladder augmentation
  • Bladder augmentation is an option in patients with small bladder capacity and poor bladder compliance despite maximal medical therapy.
  • By anastomosing a detubularized segment of bowel to the bladder, capacity can be increased and storage pressures can be lowered, minimizing upper GU tract deterioration and improving continence.
  • Depending on the segment of bowel used, problems with metabolic derangements, mucous production, stone formation, and hematuria can develop but usually respond to medical therapy.
  • If incontinence is a significant problem, a bladder neck sling procedure can be performed along with bladder augmentation.
• Urinary diversion and undiversion
  • Formal urinary diversion for neurogenic bladder is very rarely performed today. The risks of major abdominal surgery, metabolic derangements, and long-term upper GU tract deterioration are present with urinary diversion.
  • Since the advent of CIC, some patients who underwent incontinent urinary diversion as infants have undergone successful undiversion with bladder augmentation.

Consultations

Patients with myelodysplasia have a multitude of issues that require constant observation.

• Intervention by a neurosurgeon is needed, starting at birth. Patients require initial closure of the spinal defect, CSF shunting, and monitoring for cord tethering or shunt malfunction.
• Often, consultation with a neurologist is required to define defects and watch for any change in symptoms.
• If significant bone abnormalities are present, consultation with an orthopedist may be necessary.
• Parents, and eventually the child, undoubtedly need the support of a psychologist to help deal with the struggles inherent in raising a child or growing up with myelodysplasia.
• Physical therapy may also be needed.

Diet

Generally, dietary management is the first step to achieving fecal continence.

• Constipation and diarrhea both need to be avoided. The goal is to provide enough bulk to have one bowel movement per day at a socially acceptable time. Usually, digital stimulation, suppositories, or enemas are used to regulate the timing of bowel movements.
• Additionally, if the child has difficulty with constipation, altering the diet to include more fiber and the addition of bowel lubricants, such as mineral oil, may help regulate bowel movements. Adequate bowel and bladder management are crucial to optimizing social, school, and work activities.
• In addition due to neurologic and orthopedic issues, mobility is limited, reducing the patient's ability to exercise. These patients are at high risk for obesity.

Activity

Children with myelodysplasia often have limited development and/or motion of the extremities; however, no specific activity limitations are required. Children are encouraged to be as active as possible within the limitations of the defect.

Medication

Pharmacologic therapy plays an integral role in the treatment of patients with neurogenic bladder dysfunction. Treatment usually centers around 3 major elements: the use of antibiotics to prevent infection, the use of anticholinergic medications to relax the bladder and (hopefully) to increase storage capacity, and the use of alpha agonists to attempt to improve continence.

Antibiotics are used when indicated to treat acute infections and, in vesicoureteral reflux, are used as prophylaxis to prevent UTIs, pyelonephritis, and renal damage. Anticholinergic medications help suppress involuntary and uninhibited bladder contractions. This decreases urgency and incontinence and increases the bladder's functional storage capacity.

The role of alpha agonists is to increase smooth muscle tone at the bladder neck, initiating a state of urinary retention in an effort to alleviate incontinence. Thus far, the use of alpha agonists has had limited use and limited success in patients with myelodysplasia.

Anticholinergic agents

The major stimulus for bladder contraction is activation of the detrusor muscle via muscarinic cholinergic neuronal connections. Anticholinergic medications help suppress bladder contractions, especially involuntary and uninhibited contractions. This serves to decrease urgency and incontinence and to potentially increase the bladder's functional storage capacity.

Oxybutynin (Ditropan)

Synthetic tertiary amine that, similar to atropine, antagonizes the muscarinic actions of acetylcholine. Also has a direct spasmolytic effect on the detrusor muscle and the small intestine, as well as local anesthetic action. Reduces the incidence of uninhibited bladder contractions.

Tolterodine (Detrol)

Competitive muscarinic receptor antagonist for overactive bladder. Differs from other anticholinergic types because it is selective for the urinary bladder over salivary glands. Exhibits a high specificity for muscarinic receptors, and has minimal activity or affinity for other neurotransmitter receptors and other potential targets (eg, calcium channels).

Hyoscyamine (Levbid, Levsin)

Blocks action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and the CNS, which, in turn, has antispasmodic effects.

Propantheline (Pro-Banthine)

Blocks action of acetylcholine at postganglionic parasympathetic receptor sites.

Alpha agonists

The tone of the musculature at the bladder neck is mitigated by alpha-adrenergic stimulation. The role of alpha agonists is to increase tone at the bladder neck, initiating a state of urinary retention, in an effort to decrease incontinence. However, these therapies are often not very effective.

Pseudoephedrine (Sudafed)

Stimulates vasoconstriction by directly activating alpha-adrenergic receptors of the respiratory mucosa. Induces bronchial relaxation and increases heart rate and contractility by stimulating beta-adrenergic receptors.

Tricyclic antidepressants

These medications work by directly inhibiting bladder contractions through a mechanism unrelated to anticholinergic effects. They act to decrease bladder spasms and increase storage capacity.

Imipramine (Tofranil)

Facilitates urine storage by decreasing bladder contractility and increasing outlet resistance. Inhibits reuptake of norepinephrine or serotonin (5-hydroxytryptamine [5-HT]) at presynaptic neurons.

Antibiotics

These agents are used when indicated to treat acute infections. In patients with vesicoureteral reflux, they are often used as prophylaxis to prevent UTIs, which can potentially lead to pyelonephritis and renal damage.

Of the many antibiotics, 3 agents commonly used in the pediatric population are discussed below.

Trimethoprim and sulfamethoxazole (Bactrim, Septra)

Inhibits bacterial growth by inhibiting synthesis of dihydrofolic acid. Antibacterial activity includes common urinary tract pathogens except Pseudomonas aeruginosa.

Amoxicillin (Trimox, Amoxil)

Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria.

Nitrofurantoin (Furadantin, Macrodantin)

Synthetic nitrofuran that interferes with bacterial carbohydrate metabolism by inhibiting acetylcoenzyme A. Bacteriostatic at low concentrations (5-10 mcg/mL) and bactericidal at higher concentrations.

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