Bladder augmentation in children: current problems and experimental strategies for reconstruction

Complications after augmentation enterocystoplasty in children

INTRODUCTION

In the pediatric population, lower urinary tract dysfunction, usually, is due to neurogenic or anatomic defects. In this context, when conservative treatment fails, augmentation enterocystoplasty is a treatment option with good functional results. Nevertheless, multiple complications have been associated with this technique.

METHODS

We conducted a retrospective review of the patients who underwent bladder augmentation surgery at our hospital over the past 25 years. Statistical analyses were performed to identify potential factors associated with the occurrence of complications.

RESULTS

A total of 34 patients underwent augmentation enterocystoplasty during the study period. A total of 90 complications were recorded in 30 patients (88.2%). The average number of complications per patient was 2.6 ± 1.9. Reintervention was required in 28 patients (82.4%) due to complications, with a mean of 2.29 reoperations per patient. The most frequent complication was lithiasis (17/90), followed by stoma-related issues in the catheterizable duct (14/90), and urinary tract infections (10/90). Patients with exstrophy (p = 0.0028, IRR 3.4, 95% CI 1.71-6.78), bladder neck surgery (p = 0.014, IRR 2.04, 95% CI 1.29-3.21), and catheterizable duct (p = 0.002, IRR 2.56, 95% CI 1.61-4.06) had a significantly higher number of complications.

CONCLUSIONS

In our study, over 85% of patients who underwent bladder augmentation surgery experienced at least one complication during follow-up. The risk was significantly higher in patients with bladder exstrophy and in those who had a bladder neck procedure.

Bladder patch repair using mesothelial Cell-Seeded autologous granulation tissue: an experimental study in male rabbits

OBJECTIVE

Currently, bladder reconstruction using gastrointestinal segments is considered as the gold standard for bladder repair or augmentation. However, postoperative complications including bowel dysfunction, metabolic abnormalities, chronic urinary tract infection and stone formation are common. This study aims to evaluate the utility of the compound graft for bladder patch repair by seeding mesothelial cells onto autologous granulation tissue.

METHODS

22 Fr silastic tubes were implanted subcutaneously in 18 male rabbits. The animals were equally divided into two groups. In the experimental group, nine animals underwent omentum biopsies and mesothelial cells were cultured and expanded in vitro. Two weeks after the implantation, the autologous granulation tissue encapsulating the silastic tubes were harvested. The tissue was cut longitudinally and trimmed to 2 × 2 cm2. In the experimental group, mesothelial cells were seeded onto the outer surface of the tissue and cocultured for 7 days to construct a compound graft. In each animal, a full-thickness defect of 2 × 2 cm2 in the anterior wall of the bladder was created. The defect was repaired with the constructed compound graft in the experimental group and with the granulation tissue directly in the control group. The bladder was harvested and analyzed grossly and histologically at 1, 2 and 6 months postoperatively. In addition, urodynamics were performed 6 months postoperatively to evaluate the function of the bladder.

RESULTS

In the experimental group, no severe fibrosis and shrinkage were observed postoperatively and the mucosa at the grafts site appeared sleek and normal in color. Histologically, multilayers of urothelium surrounded by increasingly organized smooth muscles were observed. In contrast, severe contracture and fibrosis of the grafts occured in the control group. Gross examination of bladder mucosa revealed ulcer and stone formation at the site of the grafts. Histologically, accumulation of inflammatory cells and fibroblasts, and extensive scarring occurred. Six months after surgery, the urodynamic results showed that the experimental group had a larger bladder capacity (83.33 ± 2.08 ml vs. 76.33 ± 3.22 ml, p = 0.034), a lower maximum intravesical pressure (18.77 ± 1.79 mmHg vs. 24.02 ± 1.22 mmHg, p = 0.014) and a better bladder compliance (5.64 ± 0.8 ml/mmHg vs. 3.87 ± 0.13 ml/mmHg, p = 0.019), compared to the control group.

CONCLUSIONS

Mesothelial cell-seeded granulation tissue can be successfully used for bladder patch repair in male rabbits. With further investigations, this technique may be considered for clinical use in human. Keywords · ··.

Augmentation cystoplasty and continent catheterizable channels in the bladder exstrophy-epispadias complex: A 20-year experience

INTRODUCTION

The variable presentation of the exstrophy-epispadias complex (EEC) has led to a variety of surgical and medical care practices for management of the condition. Augmentation cystoplasty (AC) is a procedure that can be used to increase the volume and compliance of the bladder to facilitate a functional storage vessel for urine that does not put the upper urinary tract under high pressure.

OBJECTIVE

To determine risk factors for complications after augmentation cystoplasty (AC) with continent catheterizable channel (CCC) in the EEC.

STUDY DESIGN

An IRB approved institutional database of EEC patients was reviewed retrospectively. Patients that had primary augmentation performed at our institution between 2003 and 2023 were included. Gender, race, primary closure outcome, bowel segment choice for augmentation and stoma, preoperative bladder capacity, bladder neck status, age at augmentation, 30- and 90-day complications, number of stomal revisions, and length of longer term follow-ups were reviewed. Comparisons were made among different risk factors and complications across AC type and CCC type.

RESULTS

186 patients underwent primary AC with CCC at our institution and 157 met final inclusion criteria (Table 1). The patients included 148 (94.3 %) classic bladder exstrophy, 6 (3.8 %) male epispadias and 3 (1.9 %) female epispadias. The mean age at time of AC was 11.3 years with a median follow up of 6.46 years. There was no significant difference in the length of bowel harvested by the ileum and colon groups (p = 0.0836) or closure outcome (p = 0.3013). There was increased usage of Monti stoma in patients with an ileum AC (p = 0.0034). Stomal revisions were also significantly more common in the ileum group (p = 0.0392). Closure outcome did not influence the rate of 30- and 90-day complications (p = 0.6560, p = 0.6761) or stoma choice (p = 0.7384). There was no significant difference between the ileum and colon augment groups in terms of 30- and 90-day complications (p = 0.8329, p = 0.2923, respectively). Multivariate Cox regression showed no significant association between stoma or augmentation type and time to postoperative complication (p = 0.94 and p = 0.77, respectively). Patients with a history of primary successful closure had a shorter hospital stay (p = 0.0042) but there was no difference in hospital stay between the ileum and colon groups (p = 0.6632).

DISCUSSION

Bowel segment choice for AC does not influence the risk for complications in the EEC population. History of a failed primary closure leads to a longer hospital stay after AC, but there is no increased risk for complications.

CONCLUSION

Risks factors in the EEC population for complications after AC with CCC remain unknown.

Clinical and urodynamic findings in children and adolescents with neurogenic bladder undergoing augmentation cystoplasty: a systematic review

BACKGROUND

Augmentation cystoplasty (AC) is a procedure to improve the clinical and urodynamic parameters of neurogenic bladder (NB) in children and adolescents refractory to other treatments. We performed a systematic review to investigate these parameters in children and adolescents with NB undergoing AC.

METHODS

We followed PRISMA guidelines and searched electronic databases until March 2024 for studies involving patients aged three to 19 years diagnosed with NB undergoing AC. We assessed clinical and urodynamic parameters before and after surgery, focusing on improvements in urinary incontinence, vesicoureteral reflux (VUR), bladder capacity, compliance, and end filling detrusor pressure (EFP).

RESULTS

A total of 212 NB patients underwent AC and were evaluated for urinary incontinence before and after surgery. Two studies showed a 76.5% to 78.9% improvement in incontinence without bladder outlet procedures (BOP). Another study found no significant difference in incontinence improvement rates between AC with and without BOP. The VUR resolution rate assessed in three studies ranged from 12.5 to 64%. Three studies showed a variation in bladder capacity from 52.8 to 70% of the expected bladder capacity pre-AC to 95.9 to 119%, post-AC. A fourth study showed a variation in bladder capacity from 87 ml pre-AC to 370 ml post-AC. Two studies showed a variation from 3.2 to 4.6 ml/cm H2O pre-AC to 13.7 to 41.3 ml/cm H2O post-AC in bladder compliance. The EFP in three studies varied from 37.2 to 47.6 cm H2O pre-AC to 11 to 17.4 cm H2O post-AC.

CONCLUSION

After AC, urinary incontinence, bladder capacity, EFP, and bladder compliance improved in children and adolescents with NB.

Partial bladder transplantation with en bloc kidney transplant-long-term, 17 years, the outcome of a "bladder patch technique"

A transplant of a portion of the bladder with an en bloc kidney from a 2-year-old donor was previously reported in a 12-month-old girl due to her extremely small bladder. Bilateral kidneys were transplanted en bloc with their ureters connected to a patch of the donor bladder (bladder patch technique). The long-term outcomes and complications of this technique have not been documented. Here, we report a long-term, 17-year follow-up of this patient with an evaluation of whole bladder functions at 18 years of age. The patient has had no episodes of urinary tract infections. Cystoscopy showed a viable transplanted bladder with a well-perfused mucosa. We observed that the native bladder has stretched over time, forming more than half of the bladder wall. Urodynamic studies showed preserved bladder compliance at 43 mL/cmH2O, and native bladder contractility was preserved. Prolonged voiding time and postvoid residual urine were also observed. These findings were suggestive of detrusor underactivity. No reflux across the donor ureterovesical junctions was observed. The recipient was instructed to continue timed voiding and double voiding to empty the bladder. In conclusion, en bloc kidney transplantation with a bladder patch is a feasible and safe option for kidney transplant recipients with a small bladder capacity.

Pediatric Rhabdomyosarcomas of the Genitourinary Tract

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric and adolescent population, with 350 new cases diagnosed each year. While they can develop anywhere in the body, the genitourinary tract is the second most common primary location for an RMS to develop. Overall survival has improved through the increased use of protocols and multidisciplinary approaches. However, the guidelines for management continue to change as systemic and radiation therapeutics advance. Given the relative rarity of this disease compared to other non-solid childhood malignancies, healthcare providers not directly managing RMS may not be familiar with their presentation and updated management. This review aims to provide foundational knowledge of the management of RMSs with an emphasis on specific management paradigms for those arising from the genitourinary tract. The genitourinary tract is the second most common location for an RMS to develop but varies greatly in symptomology and survival depending on the organ of origin. As the clinical understanding of these tumors advances, treatment paradigms have evolved. Herein, we describe the breadth of presentations for genitourinary RMSs with diagnostic and treatment management considerations, incorporating the most recently available guidelines and societal consensus recommendations.

Factors predicting the success of intradetrusor onabotulinum toxin-A treatment in children with neurogenic bladders due to myelomeningocele: The outcomes of a large cohort

OBJECTIVE

This study aimed to determine the effectiveness of intradetrusor injections of onabotulinum toxin-A (BoNT-A) in pediatric patients with neurogenic bladders (NB) due to myelomeningocele (MMC). The factors predicting success were also evaluated.

STUDY DESIGN

We retrospectively identified 62 patients with NB due to MMC who underwent intravesical BoNT-A injection (100-300 U) between May 2013 and December 2018. Indications for BoNT-A injection were according to the European Association of Urology guidelines and included children for whom clean intermittent catheterization (CIC) and anticholinergic therapy had failed. Children who had previous bladder surgery or anti-reflux operations, coagulation disorders, myasthenia gravis, and non-neurogenic bladders were excluded. Twenty-one patients had accompanying vesicoureteral reflux (VUR). Preoperative and postoperative urodynamic parameters, clinical success, and VUR grades for all patients were recorded. Clinical success was defined as 4 h of dryness or bladder control between CICs. Logistic regression analysis was performed to evaluate the factors affecting treatment success.

RESULTS

The mean age of the children was 9 ± 3.36 years. The mean follow-up was 28.5 ± 12.2 months. Clinical success was achieved in 64.5% (n: 40) of the patients. The mean maximal cystometric capacity increased from 172.4 ± 45.6 mL to 236.3 ± 67.2 mL. The mean bladder compliance increased from 14.8 ± 8.1 mL/cm H₂O to 19.3 ± 7.4 mL/cm H₂O, and the mean maximal detrusor pressure decreased from 56.7 ± 18.8 cm H₂O to 36.6 ± 10.1 cm H₂O. Urodynamic parameters did not improve in patients with hypocompliant (fibrotic) bladders. In patients with accompanying VUR, reflux was completely resolved in 53.8% (n: 14) of the ureters, improved in 26.9% (n: 7) of the ureters, and remained unchanged in 19.2% (n: 5) of the ureters after subureteral injection.

CONCLUSION

Intradetrusor BoNT-A injections provide excellent outcomes in children with NB refractory to conservative treatments. Poor responses were observed in patients who had low-compliant bladders without detrusor overactivity.

Revascularized Pyelo-Uretero-Cystoplasty in Patients with Chronic Bladder Outlet Obstruction Due to Ectopic Ureterocele: A Safe Surgical Technique with Superior Continence Outcomes

PURPOSE

To present the outcomes of revascularized pyeloureterocystoplasty with ureterocele unroofing in end stage bladder patients with duplex system and ureterocele.

METHODS

Thirteen patients with obstruction of intrauterine outlet from an ectopic obstructive ureterocele were included. Fourteen units of duplex systems underwent upper pole partial nephrectomy in conjunction with augmentation revascularized pyeloureterocystoplaty and ureterocele unroofing. The anterior and lateral walls of the ureterocele were excised before cystoplasty, and the resultant edges of the posterior wall were sutured to the bladder epithelium. Anastomosis of the upper pole vein and artery to the inferior iliac artery and the common iliac vein was performed. Detubularization of the whole ureter was performed with exception of the intramural ureteric part that kept tubularized for 'jet/turbulent' occurrence. Five patients (control group) underwent pyeloureterocystoplasty without revascularization. Patients underwent several evaluations in long-term follow-up.

RESULTS

Patients were all dry by day and night in our long-term follow-up. Urinary incontinence improved in patients with no need for re-augmentation technique. Vesicoureteral reflux subsided in all patients postoperatively except one, who was asymptomatic. After five years, median bladder capacity rose from 128.5 ml to 395 ml and bladder compliance showed significant improvement from 15 ml/cm H₂O to 29 ml/cm H₂O, in experimental group and remained stable for 24-36 months. Median bladder capacity did not rise significantly in control group.

CONCLUSION

Pyeloureterocystoplasty is an efficient choice in this type of patients, which may prevent the recurrence of hypocompliant bladders and prevent ischemia and subsequent fibrosis.

OnabotulinumtoxinA for the treatment of neurogenic detrusor overactivity in children

AIMS

This study evaluated whether one (or more) of three doses of onabotulinumtoxinA were safe and effective to treat neurogenic detrusor overactivity (NDO) in children.

METHODS

This was a 48-week prospective, multicenter, randomized, double-blind study in children (aged 5-17 years) with NDO and urinary incontinence (UI) receiving one onabotulinumtoxinA treatment (50, 100, or 200 U; not to exceed 6 U/kg). Primary endpoint: change from baseline in daytime UI episodes. Secondary endpoints: change from baseline in urine volume at first morning catheterization, urodynamic measures, and positive response on the treatment benefit scale. Safety was also assessed.

RESULTS

There was a similar reduction in urinary incontinence from baseline to Week 6 for all doses (-1.3 episodes/day). Most patients reported positive responses on the treatment benefit scale (75.0%-80.5%). From baseline to Week 6, increases were observed in urine volume at first morning clean intermittent catheterization (50 U, 21.9 ml; 100 U, 34.9 ml; 200 U, 87.5 ml; p = 0.0055, 200 U vs. 50 U) and in maximum cystometric capacity (range 48.6-63.6 ml) and decreases in maximum detrusor pressure during the storage phase (50 U, -12.9; 100 U, -20.1; 200 U, -27.3 cmH₂ O; p = 0.0157, 200 U vs. 50 U). The proportion of patients experiencing involuntary detrusor contractions dropped from baseline (50 U, 94.4%; 100 U, 88.1%; 200 U, 92.6%) to Week 6 (50 U, 61.8%; 100 U, 44.7%; 200 U, 46.4%). Safety was similar across doses; urinary tract infection was most frequent.

CONCLUSIONS

OnabotulinumtoxinA was well tolerated and effective for the treatment of NDO in children; 200 U showed greater efficacy in reducing bladder pressure and increasing bladder capacity.

Bladder Augmentation Using Lyoplant®: First Experimental Results in Rats

Background

Congenital defects of the urinary bladder (micro- or contracted bladder, bladder exstrophy) remain a challenging problem for pediatric surgeons. Even when conservative treatment options are fully exhausted, irreversible renal dysfunction can be observed in a large number of cases that can even lead to chronic renal failure and the need for kidney transplantation. To protect kidney function bladder augmentation using intestinal tissue is commonly applied as the standard treatment method. However due to the unphysiological nature of intestinal tissue a number of problems and complications such as urinary tract infections or bladder stone formation limit the clinical success of this approach. Moreover a number of substitutes for the implementation of a bladder augmentation have been tested without success to date. Here we used an experimental model to test wether the biocompatible collagen mesh Lyoplant may be a suitable candidate for bladder augmentation.

Methods

We implanted a biocompatible collagen mesh (Lyoplant^®) in a bladder defect rat model for bladder augmentation (Lyoplant^®-group: n = 12; sham group n = 4). After 6 weeks the abdomen was reopened and the initial implant as well as the bladder were resected for histological and immunohistochemical examination.

Results

All but one rat exhibited physiological growth and behaviour after the operation without differences between the Lyoplant^®-group (n = 12) and the sham group (n = 3). One rat from the sham group had to be excluded because of a suture leakage. No wound healing complications, wound infections and no herniation were observed. After 5 weeks the implants showed an adequate incorporation in all cases. This was confirmed by immunohistological analyses where a significant cell infiltration and neovascularization was observed.

Conclusion

In summary, Lyoplant^® appears to be a promising tool in experimental bladder augmentation/regeneration in rats.