Hydronephrosis

Hydroureteronephrosis in the neurogenic patient may lead to renal deterioration, renal failure, and death. A high-pressure, poorly compliant bladder causes upper tract dilatation with or without vesicoureteral reflux. McGuire and colleagues first demonstrated the effect of elevated bladder pressure in patients with spina bifida when he noted that in patients with elevated bladder leak point pressures (>40 cm H ₂ O) there was a 68% incidence of vesicoureteral reflux and an 81% incidence of hydronephrosis. In patients with spinal cord injury Hackler and colleagues compared patients with poor bladder compliance with patients with normal bladder compliance, and showed that the group with poor compliance had more vesicoureteral reflux, 39% compared with 6%, and more hydronephrosis, 64% compared with 21%. When reflux is found in patients with neurogenic disease, it contributes further to the development of hydronephrosis. Hydronephrosis may also be caused by detrusor sphincter dysynergia and calculus disease.

Vesicoureteral reflux

In the adult with a neurogenic bladder the finding of vesicoureteral reflux should be looked on as a failure to control bladder pressure, therefore treatment should be aimed at lowering bladder pressure. Vesicoureteral reflux is primarily seen in spinal cord injured patients, particularly in patients with suprasacral injuries, and is seen in 17% to 25% of patients. Reflux may occur with all forms of bladder management, particularly with the use of an indwelling catheter. When vesicoureteral reflux is found, intermittent catheterization is the best method of bladder drainage in combination with anticholinergic drugs to lower the bladder pressure and to preserve the upper tracts. If bladder pressure can be lowered and maintained, it is rare that vesicoureteral reflux persists. When a bladder augmentation is required to lower detrusor pressure in a patient with reflux, some surgeons perform an antirefluxing surgery at the same time. The use of surgery is somewhat debatable because if a bladder augmentation is successful and results in lower detrusor pressure, reflux may resolve. The decision to reimplant should take into account grade of reflux because approximately 85% of Grade III or less reflux resolves, whereas approximately 66% of patients with Grade V reflux improve. Although an antireflux procedure in a very thickened bladder may not be an easy procedure, Hayashi and colleagues have reported minimal morbidity and good long-term outcomes with preservation of satisfactory renal outcome at a mean follow-up of 12 years in children with high-grade reflux. Persistent reflux, especially of infected urine, increases the risk of upper tract infection, may predispose to calculi formation, and lead to renal deterioration and even death from renal disease in patients with spinal cord injury. In 1965, Hackler and colleagues showed that 60% of patients with spinal cord injury who were dying of renal disease had persistent reflux. Today, with improved bladder pressure management, vesicoureteral reflux should be less of an issue.

Vesicoureteral reflux

In the adult with a neurogenic bladder the finding of vesicoureteral reflux should be looked on as a failure to control bladder pressure, therefore treatment should be aimed at lowering bladder pressure. Vesicoureteral reflux is primarily seen in spinal cord injured patients, particularly in patients with suprasacral injuries, and is seen in 17% to 25% of patients. Reflux may occur with all forms of bladder management, particularly with the use of an indwelling catheter. When vesicoureteral reflux is found, intermittent catheterization is the best method of bladder drainage in combination with anticholinergic drugs to lower the bladder pressure and to preserve the upper tracts. If bladder pressure can be lowered and maintained, it is rare that vesicoureteral reflux persists. When a bladder augmentation is required to lower detrusor pressure in a patient with reflux, some surgeons perform an antirefluxing surgery at the same time. The use of surgery is somewhat debatable because if a bladder augmentation is successful and results in lower detrusor pressure, reflux may resolve. The decision to reimplant should take into account grade of reflux because approximately 85% of Grade III or less reflux resolves, whereas approximately 66% of patients with Grade V reflux improve. Although an antireflux procedure in a very thickened bladder may not be an easy procedure, Hayashi and colleagues have reported minimal morbidity and good long-term outcomes with preservation of satisfactory renal outcome at a mean follow-up of 12 years in children with high-grade reflux. Persistent reflux, especially of infected urine, increases the risk of upper tract infection, may predispose to calculi formation, and lead to renal deterioration and even death from renal disease in patients with spinal cord injury. In 1965, Hackler and colleagues showed that 60% of patients with spinal cord injury who were dying of renal disease had persistent reflux. Today, with improved bladder pressure management, vesicoureteral reflux should be less of an issue.

Renal failure

Renal failure in neurogenic patients occurs because of chronic pyelonephritis, hydronephrosis, and renal stone formation. Vesicoureteral reflux also contributes to renal deterioration, but a high-pressure bladder also impairs renal and ureteral emptying so that reflux does not have to be present in order for a patient with a neurogenic bladder to develop hydronephrosis. Renal deterioration is most commonly seen in spinal cord–injured patients with complete neurogenic lesions, cervical lesions with quadriplegia, and in those managed with indwelling catheters. Patients with spina bifida are also at risk for renal deterioration, especially if they have detrusor overactivity with detrusor sphincter dysynergia, or if they have had aggressive treatment to increase their urethral resistance without management of their bladder pressure. Renal failure remains the leading cause of death in patients with spina bifida at all ages.

Indwelling catheters have been associated with urinary tract infection, upper tract deterioration, and renal failure.

Although a urinary diversion should lead to the creation of a low-pressure system, renal failure can still occur either because the diversion was performed too late after significant renal damage had occurred or because of obstruction, chronic infection, or chronic vesicoureteral reflux. Obstruction may result from ureteroileal anastomotic strictures, stomal stenosis, or poor conduit emptying. Most data on long-term complications of ileal conduits in neurogenic patients are obtained from the pediatric literature and are now considered historical because nowadays diversions are rarely performed in this patient population. These early series report that the rate of ureteroileal anastomotic stricture is 16.5% to 50% after 10 years. It is hoped that renal deterioration and death from renal failure in the neurogenic population is becoming less frequent as urologic care continues to improve.

Infection

All patients with a neurogenic bladder are at risk of development of a UTI, regardless of how they manage their bladder. Poor bladder emptying is a known risk factor for development of UTI. The postvoid residual volume at which an alternative form of bladder emptying should be initiated is unknown. Dromerick and Edwards have shown in a series of patients who have had a stroke that a postvoid residual of 150 mL is an independent risk factor for the development of UTI. In male patients who empty by increasing intravesical pressure, either by a Valsalva maneuver or by a Crede maneuver, reflux of urine into the prostate and seminal vesicles occurs in more than 50% of patients and can lead to other complications such as epididymo-orchitis. Elderly male patients who use condom catheter drainage have been found to have a higher rate of UTI, 63%, than nonusers, 14%.

The rate of bacteriuria following the introduction of a catheter is 5% to 8% for each day of catheterization, with a 100% incidence of bacteriuria with long-term indwelling catheters within 4 weeks. Symptomatic infection is far less common than asymptomatic catheter-associated bacteriuria, but asymptomatic bacteriuria may lead to a symptomatic infection or be indiscriminately treated, which may lead to multiply resistant bacteria. Seminal vesiculitis, prostatitis, epididymitis, and orchitis may all be seen in patients with long-term urethral catheterization with blockage of the ejaculatory and prostatic ducts. Suprapubic catheterization and intermittent catheterization reduce the risk of these infections but do not completely eliminate them. The technique of intermittent catheterization, sterile intermittent catheterization, or clean intermittent catheterization (CIC) was examined in a recent Cochrane analysis, from which there does not seem to be a difference in the incidence of UTIs. The investigators also examined coated or uncoated catheters, single or multiple-use catheters, self-catheterization, or catheterization by others. Based on these data it is not possible to state that one catheter type, technique, or strategy is better than another. The studies used in this analysis had design flaws, and further well-designed studies were strongly recommended.

The rate of bladder infection has been shown to decrease with increased frequency of catheterization, provided low-pressure storage is maintained. Treatment of symptomatic UTIs in the neurogenic patient involves treating with appropriate antibiotics, changing of all catheters once treatment is initiated, and ensuring that frequent complete emptying is achieved. In the patient with relapsing or persistent infections, a search for the source of infections must be undertaken and this may include a cystoscopy to rule out a stone, upper tract imaging to rule out stasis or a stone, and ensuring that the patient has changed all of their reusable catheters and is not reinfecting themselves.

Calculus disease

Patients with neurogenic bladders are at increased risk for urinary tract calculi caused by urinary stasis, indwelling catheters, reflux, infection, and immobility. Stasis occurs in the poorly draining upper tract, generally as a result of high intravesical pressures with or without hydroureteronephrosis and reflux. The incidence of upper tract calculi is 10% to 20% in patients with spinal cord injury, and the risk continues over time, necessitating ongoing follow-up. Treatment of upper tract calculi can be difficult owing to the poor drainage of the upper tract. Although shock wave lithotripsy may be effective at breaking a stone, the patient may be unable to clear the pieces. Ureteroscopy or a percutaneous nephrostolithotomy may represent a better treatment modality to ensure complete stone-free status postoperatively. In neurogenic patients undergoing percutaneous nephrostolithotomy the retreatment and complications rates are higher, primarily because of colonization or infections of the upper tracts. Care must be taken to ensure appropriate cultures are obtained pre- and perioperatively.

Stasis in the bladder is seen in patients with infrequent or incomplete bladder emptying. Stasis can be seen in the patient with an indwelling catheter that does not drain well or in the patient who catheterizes infrequently or fails to empty fully. As noted, bacteriuria is common in patients with neurogenic bladders and this serves as an additional lithogenic factor. DeVivo and colleagues found during an 8-year period that 36% of spinal cord–injured patients at their institution developed bladder calculi. Risk factors for stone formation in the first year included complete neurologic lesions and Klebsiella infections on admission. A follow-up study from the same institution showed that the incidence of bladder stones decreased to 8% from the 1970s to the 1990s. Bladder management played a role in the risk of stone formation. Patients with indwelling catheters had a 9-fold increased risk, and patients managed with CIC or a condom catheter had a 4-fold increased risk compared with continent patients who were catheter free. Bladder management was also noted to play a role in the bladder stone risk by Ord and colleagues, who calculated the risk of stone formation as 0% to 0.5% per year for condom catheterization with sphincterotomy, 0.2% for CIC, and 4% for patients with an indwelling catheter that increased to an annual risk of 16% following the development of 1 stone. Recurrent or persistent infection and/or persistent stone fragments likely play a role in recurrent stones. Although there are some series that conclude that the method of bladder management, particularly an indwelling catheter, does not contribute to the risk of stone formation, one needs to consider what the overall rate is in these series and when the bladder stones develop. One series that examined patients with spinal cord injury managed with suprapubic tubes found that 22% of patients developed bladder stones. Another contemporary series showed an overall rate of bladder calculi in spinal cord–injured patients of 14%, with the greatest risk being in the first 6 months following injury, in contrast to other series in which the risk was noted to be ongoing years after the injury.

A recent review of 56 studies examined variation between morbidity profiles of suprapubic catheters and CIC in older and more recent studies. It was noted in the review that if all patients are managed with anticholinergic medications, frequent catheter changes, and volume maintenance procedures, the morbidity is similar for suprapubic catheters and CIC.

Bladder diverticuli may predispose some patients with neurogenic bladders to not fully empty with self-catheterization and thus form stones in the diverticuli. Foreign objects including catheters or pubic hair in the bladder also serve as a nidus for calculi formation.

Treatment of bladder calculi in the patient with a neurogenic bladder must take into account the patient’s ability to fully empty. Although most bladder stones can be treated endoscopically through the urethra or via a percutaneous approach, the goal of the urologist should be to completely remove all stone particles. The bedridden patient with multiple sclerosis or the patient with a large redundant augmentation may not have complete bladder emptying, despite timely catheterization, because debris and mucus may layer out posteriorly and not be accessed with the catheter. Adequate fluid intake, careful and timely catheterization, daily irrigation, and eradication of urea-splitting organisms should be considered following the treatment of bladder calculi in the patient with a neurogenic bladder.