Transition of Care and Treatment of the Adult Spina Bifida Patient
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- Kalyanaraman, B. & Elliott, S.P. Curr Bladder Dysfunct Rep (2014) 9: 96. doi:10.1007/s11884-014-0229-8
Adult spina bifida patients are an underserved population in terms of healthcare in general and urologic care in particular. These patients have unique urologic issues arising from the underlying disease process as well as prior treatments. Multidisciplinary clinics deliver coordinated care in a limited number of locations and many patients receive care in their local community. In an effort to improve patient care, this article will empower the general adult urologist to care for the urologic needs of adult spina bifida patients and educate the reader about the fundamentals of transitional urologic care.
KeywordsSpina bifidaTransitional careTreatment of adult spina bifidaNeurogenic bladderUrinary incontinenceUrodynamicsUrinary tract reconstructionVoiding dysfunctionMyelodysplasia
Spina bifida (SB), also known as myelodysplasia, encompasses a spectrum of congenital neural tube defects including spina bifida occulta, spina bifida aperta, meningocele, myelomeningocele, and lipomeningocele. The incidence of SB in the United States from 2004-2006 was estimated to be 3.5 per 10,000 live births . Maternal folate deficiency, maternal obesity, pre-gestational diabetes and family history are established risk factors for SB. There has been a 31 % decline in the incidence of SB since 1998, attributable to folic acid supplementation during pregnancy and mandatory folic acid fortification of food grains [2•]. With advances in neonatal and pediatric care, 50-94 % of infants born with SB are estimated to survive into adulthood [3, 4]. However, few centers specialize in the care of adult SB patients. The Spina Bifida Association website lists 43 centers that provide care to adult SB patients, of whom only nine cater exclusively to the needs of the adults and the remaining 34 provide both pediatric and adult care . Several states do not have any adult SB clinics, which means that these patients with disabilities have to travel long distances to obtain specialized care or seek out a general adult urologist familiar with SB care. As with other disabling childhood disorders such as cerebral palsy, transitional care of the adult SB patient remains a challenge . This is evident from the fact that one-third of hospital admissions in adult SB patients are due to potentially preventable conditions, with urinary tract infection being the most common diagnosis at admission. Of all hospitalizations for such potentially preventable conditions, 37.5 % result in death of the SB patient. Healthcare costs from these hospitalizations are in excess of $360 million. Furthermore, the rate of hospitalizations is inversely proportional to age, which could be related to the point of time when adolescents or young adults with SB transition to adult care .
The burden of urologic disease in the SB population is well-known. The rising life expectancy of individuals with SB means that adult urologists will increasingly encounter such patients and will have to manage urologic sequelae of the disease and/or its treatments. This article will review the urologic needs of the SB patient transitioning into adult care and provide a framework for their care, empowering the general adult urologist to care for such patients when specialized care is not available in the community.
Urologic Issues in Adult SB Patients
The primary goals of urologic management in adult SB patients remain essentially the same as in children – to preserve renal function and maximize urinary continence. In addition, adolescents and adults with SB may have concerns regarding sexual performance. Patients can also develop urolithiasis or complications of previous urologic reconstruction.
Patients with SB are at a nine- to 11-fold increased risk of renal insufficiency when compared to the general population . Renal insufficiency was responsible for 30 % of deaths among adult SB patients undergoing follow-up in a specialized SB clinic . Therefore, the importance of lifelong surveillance of SB patients to preserve renal function cannot be overemphasized.
Lower urinary tract dysfunction (LUTD) of varying degrees is seen almost universally in patients with SB. McGuire et al. demonstrated that children with SB who had detrusor leak point pressures greater than 40 cm H2O were at increased risk of upper urinary tract deterioration (UUTD) in the form of vesicoureteral reflux or ureteral dilation [10••]. Several authors have noted the association between adverse urodynamic parameters (elevated leak point pressures, impaired compliance, detrusor external sphincteric dyssynergia) and renal insufficiency in patients with SB [11–13]. Therefore, treatment of LUTD is critical to preservation of renal function in SB patients. Over the past three decades, early institution of clean intermittent catheterization (CIC) and anticholinergic medications has become the mainstay of treatment to maintain safe detrusor pressures and facilitate bladder emptying in SB. This strategy has been shown to preserve upper urinary tracts in 90 % of children with SB . However, patients managed conservatively through puberty continue to have an increase in maximum cystometric capacity, maximum detrusor pressure, and detrusor leak point pressure. These changes have been attributed to the growth of prostate in males and estrogenization of urethra in females . Furthermore, changes in perception of body image that occur as SB patients go through adolescence may cause noncompliance with CIC or medication schedule, thereby exacerbating the risk of UUTD and renal insufficiency .
There is a risk of UUTD and renal insufficiency in SB patients in spite of urinary diversion or lower urinary tract reconstructive surgery. In a multicenter, retrospective cohort study of outcomes following incontinence surgery, eight of 230 surgically managed SB patients (3.4 %) compared to one of 191 medically managed patients (0.9 %) had increase in serum creatinine. Another four of the patients who had undergone surgery developed end-stage renal disease requiring dialysis or transplant . Urodynamic evaluation after a mean duration of 10.4 years following augmentation cystoplasty showed diminished compliance in two of 18 SB patients (11 %) . These studies highlight the importance of close urologic follow-up of SB patients even if they are asymptomatic.
Persistent urinary incontinence is a distressing problem in a majority of adults with SB. Using the definition of incontinence of at least one episode per month, Verhoef et al. reported that 60.9 % of adults with SB in their series were incontinent and 69.7 % of those patients perceived the incontinence as a problem . Interestingly, in the study by Almodhen et al., 45 % of SB patients managed conservatively through puberty became continent spontaneously and upper tracts were preserved in those patients, whereas patients who continued to be incontinent into adulthood were at higher risk of UUTD . Although the number of patients in this study was too low to draw any conclusions, the possible correlation of persistent incontinence and risk of UUTD in adults with SB is significant. The etiology of incontinence can be multifactorial including but not limited to neurogenic detrusor overactivity, incompetent sphincter, urinary tract infection, bladder calculi, constipation, noncompliance with intermittent catheterization, noncompliance with medications, or unsuccessful reconstructive surgery. Identification and correction of the cause of incontinence requires a complete urologic workup, including urodynamic studies (UDS) and urinary tract imaging.
Although rare, tethered cord syndrome can occur in adults with history of SB repair and present as worsening or new onset urinary incontinence . Urodynamic findings can include detrusor hyperreflexia, detrusor external sphincteric dyssynergia, decreased sensation or hypocontractile detrusor. Diagnosis is made by magnetic resonance imaging of the spine and requires referral to a neurosurgeon for treatment.
Studies of sexual function of adults with SB indicate that patients with lower levels of lesion have better genital sensation and sexual function. For instance, Scire et al. reported normal genital sensation in 53 % of male patients with lesions at or below L3 compared with 7.2 % of patients with lesions above L3. This trend also applied to women with SB. In this study, the levels of lesion and continence status were identified as predictors of successful sexual relationship in adults with SB . In contrast, Snyder et al. reported that caudal level of lesion, but not continence status, was a predictor of sexual function in adults with SB . However, it is does seem intuitive that continent adults would be more likely to be socially independent and therefore, more likely to engage in sexual activity. Regardless, all authors agree that sexual counseling should be an integral part of follow-up of an adult SB patient.
Consideration must also be given to pregnancy and delivery in women with SB, especially those who have undergone complex lower urinary tract reconstructive surgery. Stretching of the abdomen during pregnancy can cause stomal prolapse or retraction, and consequently difficulties with proper fitting of stomal appliance in patients with urinary diversion. In patients with continent catheterizable channels, mechanical compression from the gravid uterus can give rise to difficult catheterization, increasing incontinence, or both . Caesarian section may be indicated for reasons such as narrow pelvic outlet, inability to abduct the hips, inability to Valsalva, or previous urethral sling placement. In patients with lower urinary tract reconstructions, the augmented bladder and/or the catheterizable channel can obstruct the obstetrician’s access to the uterus during C-section. The urologist should be involved to ensure an uneventful pregnancy and delivery.
Although there is no large-scale epidemiologic study of urinary tract calculi in the SB population, studies have shown that these patients are at higher risk for nephrolithiasis than the general population due to factors such as decreased- or non-weight-bearing status recurrent urinary tract infections and lower urinary tract reconstructive surgery [24, 25]. In a recent study, Veenboer et al. studied 260 adult SB patients and reported a ten-fold higher risk of bladder calculi in these patients when compared to the general Dutch population . Indwelling urinary catheter was identified as the only risk factor for development of bladder calculi in this population.
The surgical management of urinary calculi in this patient population can be challenging due to factors such as abnormal body habitus and surgically altered anatomy of the lower urinary tract. Percutaneous treatment of renal calculi is made difficult because of skeletal deformities such as kyphosis, scoliosis, and shortened rib cage . Access to the bladder and ureters may be difficult or contraindicated if patient has undergone bladder neck reconstruction. A scope can either be passed through the catheterizable channel or one can gain percutaneous access into the bladder to perform cystolithotomy or ureteroscopy. One should avoid dilation of the catheterizable channel for cystoscope placement; instead use a flexible ureteroscope, or pediatric or adult cystoscope through the channel as indicated by the size of the channel. If cystoscopic visualization with a smaller caliber scope through a narrow channel is difficult then a percutaneous approach should be pursued.
Complications of Lower Urinary Tract Reconstructive Surgery
If conservative measures fail, SB patients undergo lower urinary tract reconstructive surgery to increase bladder capacity and compliance, decrease incontinence, or increase ease of catheterization. Surgical measures include bladder augmentation, bladder neck closure, bladder neck sling placement, continent catheterizable channel creation, artificial urinary sphincter placement, or non-continent urinary diversion . The adult SB patient may present with complications arising out of these surgical procedures even though they may have been done in the remote past.
Perforation of the augmented bladder is probably the most lethal complication that can occur in SB patients. Spontaneous perforation occurs at a rate of 6-13 % and can occur even six years after augmentation . Perforation can also occur as a result of urinary tract manipulation, such as during urodynamic investigation . Because of impaired sensation in SB patients, the clinical picture may be atypical and a high index of suspicion is required to diagnose this condition . Perforation should be suspected in any SB patient with a history of bladder augmentation who presents with fever, abdominal pain, or sepsis. CT cystogram is the most sensitive imaging modality to diagnose perforation and patients require emergent laparotomy.
Complications of continent catheterizable stomas can include false passage, stenosis, bleeding, and incontinence. Patients can present with inability to catheterize and this is an emergency in those who have undergone bladder neck closure; but even in those with an open bladder neck, catheterization of the channel should be re-established urgently in order to prevent stenosis of the channel. Although some of these complications can be resolved with minor procedures such as channel dilation or a skin-level stomal revision, others may require major revision or excision of the conduit [32, 33].
Initial Evaluation of Adult SB Patients
As always, a thorough history and physical examination are essential during the initial visit. Emphasis must be placed on voiding pattern, degree of incontinence, bowel habits, urinary tract infections, current medications, details of any prior urinary tract surgery, history of ventriculoperitoneal shunt, and history of tethered cord release. More often than not, parents accompany the SB patient during transition of care and are able to provide a detailed history of the patient’s medical care up to that point. However, it is important to communicate with the patient’s pediatric urologist and obtain records of any genitourinary surgery performed and the results of the most recent urodynamics and/or upper tract imaging. During physical examination, attention must be paid to the extent of sensory and motor deficit, abdominal scars, presence and location of stomas and any evidence of decubitus ulcers.
Baseline laboratory investigations include urine culture and basic metabolic panel including estimation of glomerular filtration rate (GFR). It has been established that serum creatinine and creatinine clearance are not accurate measures of GFR in SB patients due to their low muscle mass . Cystatin C (Cys C) is a low molecular weight protein whose serum levels are independent of body mass and composition . Therefore it is considered a better measure of GFR than serum creatinine. However, Abrahamsson et al. have shown that Cys C does not accurately diagnose patients with mild or moderately reduced GFR . Therefore, serum creatinine remains the standard method of estimating renal function in SB patients at this time.
UDS, ideally in conjunction with fluoroscopy, is valuable in the initial urologic evaluation and follow-up of certain SB patients. Multi-channel UDS including uroflowmetry, cystometrogram, pressure-flow study and electromyogram of the external sphincter is considered the standard of care for assessment of neurogenic bladder. At our institution, SB patients are not required to discontinue anticholinergic medications prior to urodynamic evaluation. This allows us to assess a patient’s bladder function on his/her current medication regimen so that dosage adjustments can be made as indicated by the results of UDS. UDS combined with fluoroscopy can detect findings such as vesicoureteral reflux, bladder diverticulum, detrusor external sphincteric dyssynergia and incompetent sphincter that may not be readily apparent on routine UDS.
Urinary tract imaging is necessary to screen for UUTD. Renal ultrasound is safe, effective, and economical for this purpose, especially given that patients need periodic imaging to monitor the kidneys. CT scan of the abdomen and pelvis can be substituted for ultrasound for the workup of conditions such as hematuria, flank pain, or recurrent UTI. A plain X-ray of the abdomen is obtained to estimate fecal load if the patient has constipation or fecal incontinence.
Surveillance of Adult SB Patients
At the time of preparation of this manuscript, there are no American Urological Association guidelines for surveillance of adult SB patients. The European Association of Urology guidelines for management of neurogenic lower urinary tract dysfunction, including SB, recommend: urinalysis every second month; renal and bladder ultrasound every six months; physical examination, blood chemistry and urine laboratory every year; and a detailed specialist examination (at the least, UDS) every 1-2 years and on demand [37••]. At our institution, SB patients with stable urinary tracts are followed up on an annual basis. Urine culture, basic metabolic panel and ultrasound of kidneys and bladder are obtained in all patients. Patients who are ten or more years post-augmentation cystoplasty undergo urine cytology and surveillance cystoscopy for bladder malignancy. This is based on the work of Soergel et al., who reported a 1.2 % incidence of malignancy in augmented bladders, assuming a 10-year lag time before the risk matures . A recent review of our cystoscopy surveillance data reveals no instance of bladder cancer in augmented bladders (unpublished data). This is consistent with the findings of Higuchi et al. who did not detect any bladder malignancy after 250 surveillance cystoscopies during a median interval of 15 years after bladder augmentation . However, given the conflicting data, advanced stage of presentation and high mortality associated with adenocarcinoma of the bladder in the SB population , we feel that the cost of annual surveillance cystoscopies in this population is well justified. In addition, patients with history of augmentation cystoplasty also undergo annual serum B12 testing if the terminal ileum has been used for reconstruction (e.g., ileocecocystoplasty). UDS is not performed as part of routine surveillance but is indicated if there is new onset or worsening of incontinence, renal insufficiency, or hydronephrosis. We also perform UDS in SB patients with recurrent urinary tract infections because the spasms felt during uninhibited detrusor contractions or reduced contractility can be perceived by the patient or healthcare provider as a urinary tract infection, especially when combined with findings of bacteriuria in these chronically colonized patients.
Overview of an Adult Spina Bifida Clinic
Other than urologic care, adult SB patients have a multitude of healthcare needs including but not limited to nephrology, neurosurgery, orthopedics, orthotics, occupational therapy, physical therapy, and wound care. In addition, these individuals need assistance from social workers to navigate the complex world of the modern healthcare system. A holistic adult SB clinic can provide a one-stop shop for these patients, thereby delivering the maximum value both to the patient and to the healthcare system. At our institution, the SB patient’s visit is coordinated with all the healthcare providers that are part of his/her care team. All patient areas are wheelchair accessible. Laboratory and imaging tests are done on the day of clinic visit prior to meeting with the healthcare provider, so that results can be discussed with the patient and a plan formulated at the same visit. An ambulatory cystoscopy suite makes it possible to perform surveillance cystoscopies and minor procedures such as intravesical Botox injection. The urology clinic is staffed by registered nurses and nurse practitioners who are also trained in performing UDS. Indeed, the nursing staff with a passion for taking care of adults with physical and cognitive disabilities forms the backbone of the adult SB clinic, which also takes care of patients with conditions such as spinal cord injury, cerebral palsy, and muscular dystrophy.
Transitional urologic care of the spina bifida patient requires basic knowledge of the management of neurogenic bladder and most adult urologists are qualified to provide this care. Complex surgical cases can and should be referred to urologists who specialize in the field of reconstructive urology. However, most adult SB patients should be able to obtain urologic care close to home by the compassionate and engaged general urologist.
Compliance with Ethics Guidelines
Conflict of Interest
Dr. Sean Elliot has received honoraria for consulting, or research grants within the last five years from American Medical Systems, INC, GT Urological, LLC, and the Gilette Foundation, outside of the submitted work. Dr. Balaji Kalyanaraman declares that he has no conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with animal subjects performed by any of the authors.