Bladder stones after bladder augmentation are not what they seem

A Rocky Road: Bladder Stones in the Augmented Exstrophy-Epispadias Complex Patient

OBJECTIVES

To determine the rate of stone formation amongst patients of the exstrophy-epispadias complex with augmentation cystoplasty. We hypothesize that bowel segment choice influences the rate of stone formation after bladder augmentation and the rate of complications from bladder stone surgery.

METHODS

An IRB approved institutional database of 1512 exstrophy-epispadias patients was reviewed retrospectively. Patients that had a history of bladder augmentation and were seen at our institution between 2003 and 2023 were included.

RESULTS

Out of 259 patients, bladder stones developed in 21.6% (56), of which the bowel segment used was colon in 147 patients and ileum in 100. Stones formed in 19% of colon augments compared to 29% ileal augments, however this was not statistically significant (p=0.07). The most common primary stone component was dahllite, followed by struvite for all augments. The median time to stone treatment after augmentation was 4.14 years (0.75-31). 74% of patients had a recurrence that required a second surgery. The median time from first to second surgery and second to third surgery was 1.4 years and 2.22 years, respectively. Bladder stone surgery complications occurred in 14% of patients, vesicocutaneous fistula being the most common, and complications did not differ by augment type. Median follow up after first stone intervention was 6.07 years (0-19.5).

CONCLUSION

The treatment of bladder stones in the exstrophy-epispadias complex remains challenging. Interventions to prevent recurrence are crucial as the majority of patients will require two or more stone surgeries in their lifetime.

Long-term risks of childhood surgery

INTRODUCTION

Several patients, who underwent major reconstruction under the care of an experienced pediatric urologist are now, as adults, several years later, appearing with long term problems and complications. This consensus process was undertaken to give an overview of long term consequences (and their management) of urological childhood surgery.

MATERIAL AND METHODS

Several known urologists with experience in life-long follow up and revisional surgery of patients with congenital conditions were asked to review literature and comment based on their experience about several complications of childhood surgery.

RESULTS

Renal impairment, metabolic consequences, bladder stones, Vit B 12 deficiency and recurrent infections are often encountered. Also recurrent ureteric strictures and difficulties with catheterizable channel (both obstruction and incontinence) can be challenging to manage. Specific attention is needed regarding female sexuality and pregnancy. Both the development of malignancies in reconstructed bladders as secondary malignancies need to be taken into account during follow up.

CONCLUSION

Follow up of patients with rare congenital conditions is highly specialized and revisional surgery can be challenging. Therefore, follow up needs to be organized in specialized centers.

Advancing autologous urothelial micrografting and composite tubular grafts for future single-staged urogenital reconstructions

Urogenital reconstructive surgery can be impeded by lack of tissue. Further developments within the discipline of tissue engineering may be part of a solution to improve clinical outcomes. In this study, we aimed to design an accessible and easily assembled tubular graft with autologous tissue, which could be constructed and implanted as a single-staged surgical procedure within the premises of an ordinary operating room. The ultimate goals would be to optimize current treatment-options for long-term urinary diversion. Therefore, we evaluated the optimal composition of a collagen-based scaffold with urothelial micrografts in vitro, and followingly implanted the construct in vivo as a bladder conduit. The scaffold was evaluated in relation to cell regeneration, permeability, and biomechanical properties. After establishing an optimized scaffold in vitro, consisting of high-density collagen with submerged autologous micrografts and reinforced with a mesh and stent, the construct was successfully implanted in an in vivo minipig model. The construct assemblance and surgical implantation proved feasible within the timeframe of a routine surgical intervention, and the animal quickly recovered postoperatively. Three weeks post-implantation, the conduit demonstrated good host-integration with a multilayered luminal urothelium. Our findings have encouraged us to support its use in more extensive preclinical large-animal studies.

Large bladder stones in an augmented bladder - An open approach to a big problem

Bladder augmentation can be a valuable life-changing operation for patients with bladder dysfunction, however, are associated with several complications that require long-term management. One of the most common complications seen in these patients are bladder calculi. If bladder stones are left untreated, they can become extremely large and cause pain, urinary tract infections, or difficulty emptying the bladder. We present the case of a patient with an augmented bladder who had numerous large bladder stones and his management.

Insights into cellular behavior and micromolecular communication in urothelial micrografts

Autologous micrografting is a technique currently applied within skin wound healing, however, the potential use for surgical correction of other organs with epithelial lining, including the urinary bladder, remains largely unexplored. Currently, little is known about the micrograft expansion potential and the micromolecular events that occur in micrografted urothelial cells. In this study, we aimed to evaluate the proliferative potential of different porcine urothelial micrograft sizes in vitro, and, furthermore, to explore how urothelial micrografts communicate and which microcellular events are triggered. We demonstrated that increased tissue fragmentation subsequently potentiated the yield of proliferative cells and the cellular expansion potential, which confirms, that the micrografting principles of skin epithelium also apply to uroepithelium. Furthermore, we targeted the expression of the extracellular signal-regulated kinase (ERK) pathway and demonstrated that ERK activation occurred predominately at the micrograft borders and that ERK inhibition led to decreased urothelial migration and proliferation. Finally, we successfully isolated extracellular vesicles from the micrograft culture medium and evaluated their contents and relevance within various enriched biological processes. Our findings substantiate the potential of applying urothelial micrografting in future tissue-engineering models for reconstructive urological surgery, and, furthermore, highlights certain mechanisms as potential targets for future wound healing treatments.

Bladder augmentation in exstrophy vesicae: Long-term results of a single experienced center

BACKGROUND

In this study, we present our long-term treatment outcomes of bladder augmentation (BA), bladder neck closure, and Mitrofanoff clean intermittent catheterization (CIC) in managing bladder exstrophy (BE).

METHODS

This was a retrospective medical records' review of 33 children diagnosed as born with BE, followed up at a tertiary pediatric urology clinic from 1988 to 2020. Outcomes such as surgical interventions, presence of renal calculi, hydronephrosis, and continence status were extracted.

RESULTS

The median follow-up of the group was 18.2 (4-26) years. Urinary system stones developed in 10 (30.3%) cases about 8.9 years after BA. Stone development was two times more common in patients who underwent colocystoplasty (33.3%) than those who underwent ileocytoplasty (16.6%). The state of continence of the group was satisfactory in 26 (78.7%; excellent in 23; good in 3 cases) and unsatisfactory (wet) in 6 (18.1%) cases. At the last visit, ultrasonography revealed no hydronephrosis in 23 (69.6%) patients, and the voiding cystourethrogram demonstrated low-grade vesicoureteral reflux in 10 (30.3%) and high-grade vesicoureteral reflux in 2 (6%) patients.

CONCLUSIONS

An elaborated plan of surgical reconstruction for classic BE can lead to satisfactory long-term urinary continence in most patients. Ultimate predictors of outcome in BE repair are difficult to ascertain. Consistently, BA, bladder neck closure, and Mitrofanoff CIC continue to stand out at a critical point in the management of those patients with classic BE. Our study demonstrated that augmentation is required to achieve acceptable dryness with high satisfactory dryness rates in BE.

Incidence of nephrolithiasis after bladder augmentation in people with spina bifida

INTRODUCTION

Risks of nephrolithiasis after bladder augmentation in people with spina bifida (SB) remain unclear. Annual incidence of nephrolithiasis in the general population is 0.01% for 10-14 years old, 0.07% for 15-19 years old and 0.2% for 20-24 years old. Our aim was to assess the incidence and risk factors of nephrolithiasis in SB patients after augmentation.

METHODS

Patients with SB and augmentation followed at our institution were retrospectively reviewed (born ≥1972, surgery 1979-2019). Patients were screened annually with renal bladder ultrasound and abdominal radiograph. Main outcome was nephrolithiasis treatment. Kaplan-Meier survival and Cox proportional hazards analysis were used. Possible predictors were assessed using stepwise forward selection (variables with p < 0.1 on univariate analysis included in multivariate analysis).

RESULTS

427 patients with SB and augmentation were included (51.8% female, 74.9% shunted). Median age at augmentation was 8.5 years (median follow-up: 12.4 years, ileum segment: 81.0%, bladder neck procedure: 60.7%, urinary channel: 74.2%) and 28.8% developed bladder stones. Overall, 47 (11.0%) patients were treated for nephrolithiasis. After correction for differential follow-up, nephrolithiasis was treated in 7.3% at 10 years, 13.2% at 15 years, and 18.0% at 20 years (Figure). Patients presented with either a urinary tract infection (46.8%), on screening (44.7%), or pain (8.5%). Stones were treated percutaneously, endoscopically or by ESWL (63.8%/34.0%/10.7%, respectively). Most were calcium stones (58.3%). On multivariate analysis, compared to younger patients, patients augmented at ≥10 years of age had 1.84 times the risk of nephrolithiasis (p = 0.01). Nephrolithiasis was more common in those who developed bladder stones (HR = 3.00, p < 0.0001). Among those with both renal and bladder stones, bladder stones typically preceded nephrolithiasis (55.2%), were treated concurrently (31.0%) and 13.8% occurred after nephrolithiasis. Gender, wheelchair use, bowel segment used, MACE and skeletal fractures were not associated with higher nephrolithiasis risk (p ≥ 0.11).

DISCUSSION

This study of a large cohort of SB patients with long-term follow-up highlights that the risk of nephrolithiasis is cumulative and related to bladder stone formation, age at augmentation and time since augmentation. An association with bladder stones suggests potential shared metabolic causes. The study's retrospective design likely led to underestimating the risk of nephrolithiasis by not capturing spontaneously passed stones.

CONCLUSION

Approximately 1% of patients with SB develop nephrolithiasis annually after augmentation. Close long-term surveillance after augmentation is strongly indicated, as nephrolithiasis incidence in augmented patient with SB is at least 10 times higher than general population. Patients with bladder stones are especially at risk.

Flexible cystoscopy and laser stone fragmentation via Mitrofanoff stoma: A case series

Objective:

This case series aimed to demonstrate that flexible cystoscopy and laser stone fragmentation via a Mitrofanoff stoma is possible and an effective treatment for symptomatic bladder stones in complex patients with inaccessible urethras and challenging anatomy.

Patients and methods:

We present three cases which were managed in a tertiary centre. The procedure involved using a flexible cystoscope via the Mitrofanoff stoma and laser stone fragmentation without the need for an access sheath.

Results:

This technique was performed safely and demonstrated successful bladder stone clearance on follow-up, with no postoperative complications.

Conclusion:

Our case series illustrates a technique that can be performed in this select group of patients in specialist centres with the relevant surgical exposure and expertise.

Level of evidence

Level 4.

Complications in adulthood for patients with paediatric genitourinary reconstruction

BACKGROUND

Caring for adults with prior paediatric genitourinary reconstruction remains a challenge for adult providers. Reconstructions typically have occurred decades before; surgical records are not always available and patients and families may be unable to convey procedures performed. Spina bifida (SB) patients are vulnerable to cognitive decline which may compound these challenges. Changes in patient body habitus and loss of function may contribute to problems with previous reconstructions.

METHODS

This is a non-systematic review of the literature and represents expert opinion where data are non-existent. This review focuses on the evaluation and management of complications arising from genitourinary reconstruction in congenital neurogenic bladder patients.

RESULTS

Common complications experienced by congenital neurogenic bladder patients include recurrent urinary tract infection, incontinence of catheterizable channel and urinary reservoir as well as malignancy as this population ages. Preservation of renal function and prevention of urinary tract infection while optimizing continence are essential guiding principles in the care of these patients. Many of the recommendations, however, are gleaned from available data in the adult spinal cord patient (a more commonly studied population) or the paediatric urologic literature due to limited studies in adult management of such patients.

CONCLUSION

Close follow-up and vigilance is warranted to monitor for infectious, mechanical and malignant complications while optimizing preservation of the upper urinary tracts and patient quality of life.

Adherence with bladder irrigation following augmentation

BACKGROUND

Patients with bladder augmentation (BA) are routinely counseled to irrigate their bladders daily. However, reports of adherence with this regimen are lacking.

OBJECTIVE

To evaluate adherence to a bladder irrigation protocol and identify risk factors associated with adherence among adults with spina bifida (SB) and BA.

STUDY DESIGN

Adults with SB after BA followed in a multidisciplinary clinic were identified (2017-2019). All patients or caregivers were taught the importance of and the technique for the bladder irrigation protocol prior to and after BA. Patient demographics (age, gender, ambulatory status, and presence of a caregiver in clinics) and surgical details (type of BA, age at surgery, length of follow-up, presence of a catheterizable channel, position of stoma, bladder neck surgery, presence of Malone antegrade colonic enema or ventriculo-peritoneal shunt, and number of stone surgeries) were obtained from the medical record. Patients reported other variables in a standardized clinic questionnaire. Answers were confirmed by health care providers. The variables included who performs clean intermittent catheterization (CIC), size of catheter, frequency of CIC, use of overnight catheterization, difficulties with CIC, number of UTIs, and continence per urethra and per catheterizable channel. Adherence to bladder irrigation was also assessed in the questionnaire. ‛Strict adherence' was defined as bladder irrigation performed ≥6 times/week with ≥120 mL of saline. For statistical analysis, a more lenient definition of ‛higher adherence' was used: bladder irrigation ≥2 times/week with at least 60 mL. ‛Lower adherence' was defined as ≤1 time/week or with less than 60 mL. Factors associated with ‛higher adherence' were assessed with non-parametric tests (Bonferroni-corrected p-value: 0.002).

RESULTS

Adherence was assessed in 87 eligible patients (60.9% females; mean age of 28.8 ± 8.2 years). No patient (0.0%) reported ‛strict adherence', and 62 and 25 patients (71.3% and 28.7%) reported ‛higher' and ‛lower' adherence' to bladder irrigation, respectively. Nine patients (10.3%) in the ‛lower adherence' group did not irrigate at all. No variables were statistically significant on univariate analysis, including previous bladder stone surgery or having a channel (p ≥ 0.01). On exploratory analysis, higher adherence was only associated with self-catheterizations versus those performed by caregivers (76.7% vs 33.3%, p = 0.01).

CONCLUSIONS

Adherence to a bladder irrigation protocol in adults with SB and BA is poor. A history of bladder stones requiring surgery and the presence of a catheterizable channel do not appear to affect adherence. It remains unclear why some patients are more likely than others to irrigate their bladders. Future work will focus on methods to improve adherence.

Augmentation cystoplasty in the patient with neurogenic bladder

PURPOSE

To review the indications and techniques of augmentation cystoplasty (AC) in patients with neurogenic bladder (NGB) while also examining the long-term outcomes, complications, and follow-up surgeries.

METHODS

PubMed/MEDLINE, Cochrane Library, and Embase databases were searched for articles related to AC and NGB.

RESULTS

AC is indicated for an overactive or poorly compliant bladder refractory to conservative therapies, such as anticholinergic medications and bladder botulinum toxin injections. A variety of surgical techniques using gastrointestinal segments, alternative tissues, and synthetic materials have been described, though bowel remains the most durable. Ileocystoplasty is the most common type of AC, which uses a detubularized patch of ileum that is anastomosed to a bivalved bladder. Some patients undergo concomitant surgeries at the time of AC, such as catheterizable channel creation to aid with clean intermittent catheterization, ureteral reimplantation to treat vesicoureteral reflux, and bladder outlet procedure to treat incontinence. Following AC, the majority of patients experience an improvement in bladder capacity, compliance, and continence. Most patients also experience an improvement in quality of life. AC has significant complications, such as chronic UTIs, bladder and renal calculi, metabolic disturbances, bowel problems, perforation, and malignancy. AC also has a high rate of follow-up surgeries, especially if the patient undergoes concomitant creation of a catheterizable channel.

CONCLUSIONS

Enterocystoplasty remains the gold standard for AC, though more research is needed to better evaluate the morbidity of different surgical techniques and the indications for concomitant surgeries. Experimental methods of AC with tissue engineering are a promising area for further investigation.

Bladder Augmentation (Enterocystoplasty): the Current State of a Historic Operation

PURPOSE OF REVIEW

The goal of this paper was to evaluate the current use of enterocystoplasty, a historical operation for bladder dysfunction but with continued and increasing modern relevance.

RECENT FINDINGS

Since the advent of third line neuromodulation techniques for neurogenic and idiopathic overactive bladder (OAB), the usage of enterocystoplasty has decreased. However, this procedure continues to be utilized in pediatric urology patients and the most refractory OAB patients. Adult urologist should be familiar with this operative technique in an effort to manage pediatric patients transitioning to adulthood. Minimally invasive techniques for this surgical procedure have been described with very limited outcome data. It is important for all urologists to be familiar with enterocystoplasty, both technically and with the unique needs of these patients postoperatively. Further studies evaluating the outcomes of this procedure in idiopathic overactive bladder patients and efforts to standardize recommendations for neurogenic bladder patients will help guide care in the future.

Long-term Outcomes of Augmentation Cystoplasty in a Pediatric Population With Refractory Bladder Dysfunction: A 12-Year Follow-up Experience at Single Center

PURPOSE

Augmentation cystoplasty (AC) is a surgical procedure used in adults and children with refractory bladder dysfunction, including a small bladder capacity and inadequate bladder compliance, and in whom conservative and medical treatment has failed. This study was aimed to determine the long-term outcomes of AC in children.

METHODS

A retrospective analysis was conducted of 42 patients (31 males; mean age, 14.2±6.2 years) who underwent AC for neurogenic and nonneurogenic bladder dysfunction, with a median 12.0±1.5 years of follow-up. All patients underwent AC using the ileum with or without continent reconstruction. Pre-AC, concurrent, and post-AC procedures and complications were analyzed. Patients who underwent ureterocystoplasty, were lost to follow-up, or had less than 10 years of follow-up were excluded. The primary outcomes were the complication and continence rates, the post-AC linear rate of height and weight gain, and renal function. The Student t-test was used to evaluate between-group differences and the paired t-test was used to evaluate longitudinal changes in measured variables.

RESULTS

Renal function was stable or improved in 32 of 42 patients (76.2%), with a post-AC continence rate of 88.1%. Thirty patients (71.4%) required 72 procedures post-AC. There was no statistically significant difference in the mean percentile of height (P=0. 212) or weight (P=0.142) of patients in the pre- and post-AC periods. No cases of bladder perforation or malignancy were detected.

CONCLUSION

We consider AC to be a safe and effective procedure that does not negatively affect future physical growth, while achieving a good rate of stable renal function. Patients need long-term follow-up to address long-term complications.

Nephrological and urological complications of homozygous c.974G>A (p.Arg325Gln) OSGEP mutations

BACKGROUND

Galloway-Mowat syndrome (GAMOS) (OMIM #251300) is a severe autosomal recessive disease characterized by the combination of early-onset steroid-resistant nephrotic syndrome (SRNS) and microcephaly with brain anomalies caused by WDR73 as well as OSGEP, TP53RK, TPRKB, or LAGE3 mutations.

OBJECTIVE

We report on the hitherto undescribed urological and nephrological complications of the homozygous c.974G>A (p.Arg325Gln) OSGEP mutations in a 7-year-old Caucasian girl.

CASE DIAGNOSIS

The patient came to the attention of pediatric nephrology at the age of 3 years and 11 months, when she presented with status epilepticus due to profound hypomagnesemia (0.31 mmol/L, normal 0.65-1.05). A 24-h urine demonstrated a magnesium loss of 0.6 mmol/kg/day with associated proteinuria suggesting renal tubulopathy. Subsequently, she developed recurrent urinary tract infections (UTIs) and was diagnosed with neurogenic bladder dysfunction. The patient continued to have UTIs associated with seizures and sequential cultures growing multi-drug-resistant organisms despite of antibiotic prophylaxis. In addition, the proteinuria (median microalbumin/creatinine ratio 647 mg/mmol) increased, and she developed partial Fanconi syndrome. At age 7, she developed a large bladder calculus (3.3 × 3.2 cm) and three left non-obstructing renal calculi associated with elevated urinary cystine, hypercalciuria, and ongoing hypomagnesemia and required surgical intervention. Glomerular filtration rate (GFR) remained normal and she never developed frank nephrotic syndrome (average albumin 31 g/L).

CONCLUSIONS

It is unclear if patients with OSGEP mutations with tubular symptoms rather than nephrotic syndrome should be considered a different entity. Nephrological and urological complications of OSGEP mutations can be challenging and require a multidisciplinary approach.

Neuropathic Bladder and Augmentation Cystoplasty

Surgical indications for individuals with neuropathic bladder include unsafe urinary storage pressures, progressive upper tract deterioration, and continued urinary incontinence that is recalcitrant to oral pharmacologic or intradetrusor injection therapy and intermittent catheterization. Bladder augmentation is currently the gold standard surgical procedure used to increase bladder capacity and reduce storage pressures but has significant long-term risks. The medical and surgical management of neuropathic bladder, as well as long-term consequences of bladder augmentation, are reviewed.

Advances in Pediatric Urinary Diversion

Pediatric urinary diversion is performed for a unique set of indications with many options to consider. Although surgical intervention has decreased in necessity overall due to advances in expectant management, it remains an important tool. There are many options and various factors to consider in choosing the right type of diversion for an individual and these patients require lifelong follow-up with a pediatric urologist and eventually an adult urologist. This article provides a detailed review of the most relevant techniques used by pediatric urologists for urinary diversion.

A case of base rate bias, or are adolescents at a higher risk of developing complications after catheterizable urinary channel surgery?

OBJECTIVE

Adolescents are considered to be at high risk of developing complications after lower genitourinary tract reconstruction. This perception may be due to base rate bias, where clinicians favor specific information (adolescents with complications), while ignoring more general information (number of total adolescents being followed). The goal of this study was to assess whether age was a true risk factor for subfascial and stomal revisions after continent catheterizable urinary (CCU) channel procedures.

MATERIALS AND METHODS

Consecutive patients aged <21 years and who underwent appendicovesicostomy and Monti surgery at the present institution were retrospectively reviewed; demographic and surgical data were collected. Time to subfascial or stomal revision was stratified by age at initial surgery (child: <8, preteen: 8-12, adolescent: 13-17, adult: ≥18 years old) and analyzed with Cox proportional-hazards regression. Secondary analyses included: different age categories at initial surgery (<8, 8-11, 12-15, 16-19, ≥20 years), analyzing age as a continuous and a time-varying covariate.

RESULTS

Of the 510 patients with CCU channels (median age at surgery: 7.9 years), 63 (12.4%) had subfascial and 53 (10.4%) had stomal revision (median follow-up: 6.8 years). Median age at subfascial and stomal revision was 11.3 and 10.3 years, respectively. Preteens contributed 33.0% and adolescents contributed 29.3% of the total follow-up time (3263.9 person-years). Over 80% of revisions occurred within 5 years of surgery, regardless of age at initial surgery (P ≥ 0.57) (Summary table). On multivariate analysis, age at initial surgery was not associated with undergoing subfascial (P ≥ 0.62) or stomal revisions (P ≥ 0.69). Montis were 2.1 times more likely than appendicovesicostomies to undergo a subfascial revision (P = 0.03). No other variables were associated with the risk of subfascial or stomal revision (P ≥ 0.11). Secondary analyses provided similar results.

DISCUSSION

Since the median age at surgery was 8 years old and most complications occurred within the first 5 years of follow-up, it is not surprising that most revisions occurred in 8-13 year olds. Pediatric urologists appear to base their impression of adolescents being "high risk" on specific information (adolescents having complications), while subconsciously ignoring more general information (adolescents represent a large proportion of patients in follow-up). This study had several limitations: channel complications treated non-surgically (e.g. prolonged catheterization) were not included. The findings may not be generalizable to other genitourinary reconstructive procedures or clinical settings.

CONCLUSIONS

While complications were twice as high in Monti channels than appendicovesicostomies, no single age group was at increased risk. The impression that adolescents are a high-risk group appears to represent a base rate bias.

Long-term follow-up of composite bladder augmentation incorporating stomach in a multi-institutional cohort of patients with cloacal exstrophy

INTRODUCTION

Composite bladder augmentation, incorporating gastric and bowel segments, has the theoretical advantage of metabolic neutrality while potentially avoiding the morbidities of gastrocystoplasty, such as hematuria-dysuria syndrome. The most common indication for this operation is a paucity of bowel, such as in cloacal exstrophy. Despite several early descriptive studies of this technique, there are no reports, to date, of long-term follow-up in this population.

OBJECTIVE

To describe the outcomes of composite bladder augmentation utilizing stomach in a cohort of cloacal exstrophy patients.

MATERIALS AND METHODS

A retrospective review of cloacal exstrophy patients who underwent composite bladder augmentation from 1984 to 2006 at two institutions was performed. The incidence of mortality and morbidities related to augmentation was evaluated.

RESULTS

Eleven patients with cloacal exstrophy underwent composite bladder augmentation. Median age at initial augmentation was 6.4 years (interquartile range (IQR) 4.4-9.1). Median follow-up was 13.2 years (IQR 11.2-24.6). The Summary table describes the types of composite bladder augmentations. Of the three patients with pre-operative metabolic acidosis, two improved with composite bladder augmentation and one developed metabolic alkalosis. Three developed hematuria-dysuria syndrome: one improved with staged ileocystoplasty, and two had persistent symptoms successfully treated with H2 receptor blockers. Two of 11 developed symptomatic bladder stones. There were no reported bladder perforations, bladder malignancies, conversions to incontinent urinary diversions, or deaths.

CONCLUSION

With long-term follow-up, very few patients developed metabolic acidosis/alkalosis after composite bladder augmentation. The composite bladder augmentation will continue to be used in patients with cloacal exstrophy, in order to minimize the impact on the pre-existing short gut in these patients.

Characterization of Urolithiasis in Patients Following Lower Urinary Tract Reconstruction with Intestinal Segments

PURPOSE

Urinary diversion and augmentation cystoplasty are associated with long-term complications, including metabolic derangements, infectious complications, and urolithiasis. The aim of this series was to characterize upper and lower urinary tract (LUT) calculi in this population.

METHODS

A retrospective chart review was performed on all patients with a history of urinary diversion or augmentation cystoplasty who subsequently underwent treatment for urolithiasis between January 1998 and May 2015. Data collected included demographics, perioperative characteristics, type of reconstructive procedure, urine culture, stone analysis, and metabolic evaluation. A statistical analysis was performed.

RESULTS

Ninety-nine patients were identified with a history of urolithiasis and incontinent urinary diversion (28), neobladder (21), continent cutaneous diversion (12), and augmentation cystoplasty (38). LUT stones were more common than upper tract stones in all except for incontinent diversions, which only had one lower tract stone (p = 0.0001). Twenty-three percent of stones were metabolic. Several metabolic derangements were noted, including hypocitraturia (100%), elevated urine pH (100%), low urine volume (70%), and hyperoxaluria (35%). There was a 44% rate of recurrent urolithiasis.

CONCLUSIONS

Given the high rate of stone recurrence among patients with a history of urinary diversion and augmentation cystoplasty, all measures should be taken to prevent recurrent stones. In addition to actions aimed to prevent infectious stones such as bladder and pouch irrigation, we recommend these patients undergo a full metabolic workup with targeted dietary changes and medical therapies.