The incidence of nephrolithiasis in patients with spinal neural tube defects

Percutaneous nephrolithotomy in patients with spinal cord injury: should all these patients be automatically assigned a Guy's stone score of 4?

PURPOSE

To assess the complication and stone-free rates of PCNL in patients with spinal cord injury (SCI) and to evaluate whether this population should be assigned a Guy's stone score (GSS) of 4.

METHODS

A case-control study was conducted, and electronic charts were reviewed to search for patients with SCI, bladder dysfunction, and kidney stones who had undergone PCNL. Control cases were randomly selected from among patients with complete staghorn calculus (GSS = 4).

RESULTS

One hundred and seventeen patients were included. Patients with SCI had a significant shorter operative time (119 vs. 141 min; p = 0.018). There were no significant differences between the groups in terms of the patients' position, number of renal tracts, bleeding or transfusion rate; however, there was a significantly higher complication rate (23.1% vs. 7.8%; p = 0.009) and a longer hospital stay (5.8 vs. 3.1 days; p = 0.002) among patients with SCI. With regards to the stone-free rate in patients with different grades of GSS patients with SCI who had a GSS of 1 had a stone-free rate of 85.7%, while those with a GSS of 2, 3, or 4 had 50%, 50%, and 31.5%, respectively (p = 0.024). Only patients with a GSS of 4 in the SCI group had outcomes that were similar to those of control patients (31.5% vs. 31.6%).

CONCLUSION

Patients with SCI should not be automatically assigned GSS 4. Stone-free rate is related to stone burden in these patients, although they do show a higher complication rate and a longer hospital stay than non-neurological patients.

Patient Characteristics Associated With Completion of 24-hour Urine Analyses Among Children and Adolescents With Nephrolithiasis

OBJECTIVE

To inform the development of strategies to improve adherence to guidelines, we sought to identify characteristics of pediatric patients with nephrolithiasis associated with completing 24-hour urine analyses.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients with nephrolithiasis aged 3-18years treated in a large pediatric healthcare system from May 2012 to May 2017. Multivariable Cox models were fit to estimate the association between patient characteristics and completion of a 24-hour urine analysis.

RESULTS

Among 623 patients, 317 (50.9%) completed a 24-hour urine collection. Median age was 14.4years (interquartile range [IQR] 10.5, 16.3). In adjusted analyses, age at diagnosis (hazard ratio [HR] 1.03; 95% confidence interval [CI] 1.01-1.07), renal colic on presentation (HR 1.72; 95% CI 1.15-2.58), and family history of nephrolithiasis (HR 1.50; 95% CI 1.17-1.93) were associated with an increased likelihood of completion of a 24-hour urine. Public/government assistance insurance (HR 0.68; 95% CI 0.48-0.96) was associated with decreased likelihood of completing a 24-hour urine.

CONCLUSION

Patients who had prior painful experiences with stones (renal colic), and potential better understanding of nephrolithiasis (family history, older age on presentation) were more likely to complete a 24-hour urine. Those patients with public insurance/government assistance were less likely to complete a 24-hour urine. These results can be used to develop strategies to improve pediatric patients' adherence to completing 24-hour urine collections.

Bladder Management and Continence Outcomes in Adults with Spina Bifida: Results from the National Spina Bifida Patient Registry, 2009 to 2015

PURPOSE

Most children with spina bifida now survive into adulthood, although most have neuropathic bladder with potential complications of incontinence, infection, renal damage and diminished quality of life. In this study we sought to 1) describe contemporary bladder management and continence outcomes of adults with spina bifida, 2) describe differences from younger individuals and 3) assess for association with socioeconomic factors.

MATERIALS AND METHODS

We analyzed data on bladder management and outcomes in adults with spina bifida from the National Spina Bifida Patient Registry. A strict definition of continence was used. Results were compared to young children (age 5 to 11 years) and adolescents (12 to 19). Statistical analysis compared cohorts by gender, ethnicity, spina bifida type, lesion level, insurance status, educational attainment, employment status and continence.

RESULTS

A total of 5,250 patients with spina bifida were included, of whom 1,372 (26.1%) were adults. Of the adult patients 45.8% did not take medication, but 76.8% performed clean intermittent catheterization. Continence was decreased in adults with myelomeningocele (45.8%) vs those with nonmyelomeningocele spina bifida (63.1%, p <0.0001). Continence rates were higher in the older cohorts with myelomeningocele (p <0.0001) but not in those with nonmyelomeningocele spina bifida (p = 0.1192). Bladder management and history of urological surgery varied among age groups. On univariate analysis with spina bifida related or socioeconomic variables continence was significantly associated with educational level but on multivariable logistic regression analysis bladder continence was significantly associated with employment status only.

CONCLUSIONS

Bladder management techniques differ between adults and children with spina bifida. Bladder continence outcomes were better in adults, with nearly half reporting continence. Continence was significantly associated with employment status in patients age 25 years or older.

Urinary tract stone development in patients with myelodysplasia subjected to augmentation cystoplasty

Patients with myelodysplasia who have undergone augmentation cystoplasty are at risk for urinary tract stones. We sought to determine the incidence and risk factors for stone development in this population. The charts of 40 patients with myelodysplasia who have undergone augmentation cystoplasty were reviewed. None had a prior history of urinary tract stones. All patients were seen on an annual basis with plain abdominal imaging, renal ultrasonography, and laboratory testing. Statistical analysis included a multivariable bootstrap resampling method and Student's t-test. Fifteen (37.5%) patients developed stones, 14 with bladder stones and 1 with a solitary renal stone, at a mean of 26.9 months after augmentation. Five (33.3%) developed recurrent bladder stones. The patient with a renal stone never developed a bladder stone. The mean follow-up for the stone formers was 117.2 months and for non-stone formers was 89.9 months. The stone incidence per year was 6.8%. Risk factors included a decline in serum chloride after augmentation (P = .02), female sex, younger age at time of augmentation, longer time period since augmentation, and bowel continence. A significant proportion of patients with myelodysplasia subjected to augmentation cystoplasty develop urinary tract stones, predominantly in the bladder. Dehydration may play a role in development of lower urinary tract stones as the decline in serum chloride suggests contraction alkalosis, which could lead to constipation and improved bowel continence. Therefore, improved hydration should be a goal in this cohort.

Congenital causes of neurogenic bladder and the transition to adult care

The population of patients with congenital genitourinary disorders has unique healthcare demands that require an additional interpersonal and medical skillset. Adults with congenital neurogenic bladder may have complex urinary anatomy, abnormal bladder function and atypical voiding mechanisms. While initial surgery and care of these patients is typically managed by a pediatric urologist, growth and development into adulthood necessitates transition of care to an adult care team. Failure of transition to adult care has been demonstrated to result in lower quality healthcare and increased risk of developing preventable complications.

A snapshot of the adult spina bifida patient - high incidence of urologic procedures

Introduction

To describe the urologic outcomes of contemporary adult spina bifida patients managed in a multidisciplinary clinic.

Material and methods

A retrospective chart review of patients seen in our adult spina bifida clinic from January 2004 to November 2011 was performed to identify urologic management, urologic surgeries, and co-morbidities.

Results

225 patients were identified (57.8% female, 42.2% male). Current median age was 30 years (IQR 27, 36) with a median age at first visit of 25 years (IQR 22, 30). The majority (70.7%) utilized clean intermittent catheterization, and 111 patients (49.3%) were prescribed anticholinergic medications. 65.8% had urodynamics performed at least once, and 56% obtained appropriate upper tract imaging at least every other year while under our care. 101 patients (44.9%) underwent at least one urologic surgical procedure during their lifetime, with a total of 191 procedures being performed, of which stone procedures (n = 51, 26.7%) were the most common. Other common procedures included continence procedures (n = 35, 18.3%) and augmentation cystoplasty (n = 29, 15.2%). Only 3.6% had a documented diagnosis of chronic kidney disease and 0.9% with end-stage renal disease.

Conclusions

Most adult spina bifida patient continue on anticholinergic medications and clean intermittent catheterization. A large percentage of patients required urologic procedures in adulthood. Patients should be encouraged to utilize conservative and effective bladder management strategies to reduce their risk of renal compromise.

Complications of surgical management of upper tract calculi in spina bifida patients: analysis of nationwide data

PURPOSE

The management of upper urinary tract stones in patients with spina bifida is challenging but poorly described in the literature. We compared urolithiasis interventions and related complications in patients with spina bifida to those in other stone formers using a national database.

MATERIALS AND METHODS

We retrospectively reviewed the NIS to identify hospital admissions for renal and ureteral stones from 1998 to 2011. We used ICD-9-CM codes to identify urological interventions, including shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy and ureteral stent placement. NSQIP data were used to identify postoperative complications.

RESULTS

We identified 4,287,529 weighted stone hospital admissions, including 12,315 (0.3%) of patients with spina bifida. Compared to those without spina bifida the patients with spina bifida who had urolithiasis were significantly younger (mean age 34 vs 53 years), more likely to have public insurance (72% vs 44%) and renal vs ureteral calculi (81% vs 58%), and undergo percutaneous nephrolithotomy (27% vs 8%). After adjusting for age, insurance, comorbidity, treatment year, surgery type, stone location and hospital factors patients with spina bifida were more likely to have urinary tract infections (OR 2.5), urinary complications (OR 3.1), acute renal failure (OR 1.9), respiratory complications (OR 2.0), pneumonia (OR 1.5), respiratory insufficiency (OR 3.2), prolonged mechanical ventilation (OR 3.2), sepsis (OR 2.7), pulmonary embolism (OR 3.0), cardiac complications (OR 2.4) and bleeding (OR 1.6).

CONCLUSIONS

Compared to those without spina bifida the patients with spina bifida who were hospitalized for urolithiasis were younger, and more likely to have renal stones and undergo percutaneous nephrolithotomy. Urolithiasis procedures in patients with spina bifida were associated with a significantly higher risk of in-hospital postoperative complications.

Development of upper tract stones in patients with congenital neurogenic bladder

OBJECTIVE

Patients with neurogenic bladder are at increased risk of developing upper tract stones. We hypothesized that patients with lower urinary tract stone disease are at greater risk of developing upper tract stones.

METHODS

We performed a 10-year retrospective case-control study of patients with neurogenic bladder to determine the association between bladder and upper tract stones. Independent risk factors for upper tract stones were assessed. Cases and controls were matched 1:1. Univariable analysis was performed by Fisher's exact test and the Mann-Whitney U test. Multivariable logistic regression was performed.

RESULTS

52 cases and controls were identified. Cases were significantly more likely to be non-ambulatory, have bowel-urinary tract interposition, thoracic level dysraphism, and history of bladder stones. On multivariable analysis, independent predictors of stone formation were male sex (OR 2.82; p = 0.02), dysraphism involving the thoracic spine (OR 3.37; p = 0.014) bowel-urinary tract interposition (OR 2.611; p = 0.038), and a history of bladder stones (OR 3.57; p = 0.015).

CONCLUSION

Patients with neurogenic bladder are at increased risk for upper tract stones. The presence of bladder stones may herald the development of upper tract stones. The predictors of stone disease identified should guide prospective studies to better understand the natural history of upper tract stone development in this population.

Unilateral hypercalciuria: a stealth culprit in recurrent ipsilateral urolithiasis in children

PURPOSE

Hypercalciuria is a risk factor for nephrolithiasis. We hypothesized that children with recurrent stones in 1 but not both kidneys and a normal 24-hour bladder urine calcium-to-creatinine ratio might exhibit isolated hypercalciuria of the affected kidney.

MATERIALS AND METHODS

Patients 18 years or younger with symptomatic urolithiasis who had undergone ureteroscopic stone removal were included. All subjects underwent 24-hour bladder urinalysis. Subjects with an increased urine calcium-to-creatinine ratio from the 24-hour urine collection were excluded. The 4 subject cohorts defined were 1) single stone episode in 1 kidney, 2) single stone episode in both kidneys, 3) recurrent stone episodes on 1 side and 4) recurrent stone episodes on both sides. All urine collections were obtained at ureteroscopy. Urine was obtained from the bladder and from the renal pelvis of the kidney forming the stone. Spot urine calcium-to-creatinine ratio was determined from these samples.

RESULTS

A total of 329 patients were included. Nine of 74 subjects (12%) with recurrent stone episodes on 1 side had increased spot urine calcium-to-creatinine ratio from the affected kidney. No patients in the other cohorts had increased spot urine calcium-to-creatinine ratio. Patients who formed recurrent stones in 1 kidney had increased spot urine calcium-to-creatinine ratio in the affected kidney vs other stone formers (ANOVA p <0.001).

CONCLUSIONS

Unilateral hypercalciuria can occur in children with normal calcium levels in bladder urine. Unilateral hypercalciuria should be considered as a risk factor for nephrolithiasis in children with recurrent stone episodes in 1 kidney only.