Dominic Frimberger

Challenges in a larger bladder replacement with cell-seeded and unseeded small intestinal submucosa grafts in a subtotal cystectomy model

To evaluate small intestinal submucosa (SIS), unseeded or seeded, as a possible augmentation material in a canine model of subtotal cystectomy.

Growth of bone marrow stromal cells on small intestinal submucosa: an alternative cell source for tissue engineered bladder

To assess the potential use of bone marrow stromal cell (BMSC)‐seeded biodegradable scaffold for bladder regeneration in a canine model, by characterizing BMSCs and comparing them to bladder smooth muscle cells (SMCs) by immunohistochemistry, growth capability, and contractility.

Management of Urachal Remnants in Early Childhood

PURPOSE Generally, it is recommended that all urachal remnants be excised to avoid recurrent disease and possible malignant transformation later in life. However, spontaneous resolution with no need for further intervention has been reported. We reviewed the experience with urachal remnants at a single institution and evaluated which patients could be treated nonoperatively and which required surgical intervention. MATERIALS AND METHODS We reviewed the medical records and radiographic studies of all patients with urachal remnants from January 1999 to January 2007. Patients were analyzed according to initial presentation, imaging findings and treatment. Serial clinical examinations and radiographic imaging were used to follow patients. RESULTS An external urachal sinus was found in 9 patients (39.1%) and 1 was surgically excised. Of the 12 urachal cysts (52.2%) 9 ultimately required surgical excision, of which 6 were infected initially. A patent urachus was found in 2 patients, which resolved during an observation period. Radiographic imaging and/or physical examination diagnosed all remnants initially and confirmed complete resolution during followup. Eight of the 10 urachal remnants (80.0%) that resolved developed in patients younger than 6 months. Various accompanying urogenital anomalies were found in 8 patients (34.8%). CONCLUSIONS A small urachal remnant, especially at birth, may be viewed as physiological. Urachal remnants in patients younger than 6 months are likely to resolve with nonoperative management. However, if symptoms persist or the urachal remnant fails to resolve after 6 months of age, it should be excised to prevent recurrent infections.

Occurrence of Urinary Tract Infection in Children With Significant Upper Urinary Tract Obstruction

OBJECTIVES Ureteropelvic junction obstruction and obstructive megaureter are common causes of upper urinary tract obstruction. Recent data have demonstrated that the rate of urinary tract infection (UTI) among children with upper tract obstruction not treated with prophylactic antibiotics is >36%. The aim of this study was to evaluate the occurrence of UTI in our patients with ureteropelvic junction obstruction and megaureter to better assess the role of prophylactic antibiotics. METHODS A retrospective analysis was conducted. The inclusion criteria were grade 3 or 4 hydronephrosis secondary to obstructive megaureter or ureteropelvic junction obstruction in children not maintained on prophylactic antibiotics. UTI was defined as a culture-documented symptomatic infection. Fishers exact tests were used to evaluate for an association between the occurrence of UTI with sex, level of obstruction, grade of hydronephrosis, and circumcision status. RESULTS A total of 92 patients met the study criteria. The rate of UTI in all patients was 4.3% (95% confidence interval 0.2%-8.6%). No statistically significant difference in the infection rate was noted according to sex, obstruction level, hydronephrosis grade, or circumcision status. CONCLUSIONS Our results have demonstrated a low occurrence of UTI in antenatally diagnosed patients not maintained on antibiotics. We have concluded that antibiotic prophylaxis is unlikely to benefit most children with grade 3 or 4 hydronephrosis secondary to upper tract obstruction.

Operative Versus Nonoperative Management of Ureteropelvic Junction Obstruction in Children

OBJECTIVES To describe and validate our strategy for treating patients with ureteropelvic junction obstruction operatively or nonoperatively according to ultrasonography and nuclear renal scan findings. METHODS A retrospective analysis of 243 patients from 1999 to 2006 with grade 3-4 hydronephrosis was performed. Depending on the grade of hydronephrosis with parenchymal thinning on ultrasonography and renal function on the nuclear renal scan, patients were treated with immediate pyeloplasty, pyeloplasty after a period of observation, or observation only. RESULTS Of 243 patients, 116 were found to have UPJO as determined by a half-life >20 minutes. The mean follow-up was 24.0 months (range 3-69). Immediate pyeloplasty was performed in 32 children, and 84 were treated conservatively. Crossover from observation to surgery occurred in 47 children. In the immediate pyeloplasty group, the mean pre- and postoperative differential function was 30.4% and 38.8%, respectively (P < .0001). In the observation-only group (n = 37), the initial mean renal function was 41.4% and stayed stable throughout the follow-up period, at a mean of 43.2% (P = .2764). In the delayed pyeloplasty group (n = 47), the initial mean renal function was 35.9% and increased to a mean of 41.6% after intervention (P = .0003). The median improvement of hydronephrosis on ultrasonography for those who underwent immediate surgery from before to after the intervention was from grade 4 to grade 3 (P < .0001). For those not undergoing surgery, it improved from grade 4 to grade 2.25 (P = .0026) and for those who underwent delayed surgery, from grade 4 to 3 (P = .0003). CONCLUSIONS According to our findings, the serial ultrasonography findings and initial renal function on nuclear renal scan are better indicators than the half-life alone for determining whether pyeloplasty is indicated.

Bladder regeneration in a canine model using hyaluronic acid-poly(lactic-co-glycolic-acid) nanoparticle modified porcine small intestinal submucosa

Whats known on the subject? and What does the study add?

Regional variations in small intestinal submucosa evoke differences in inflammation with subsequent impact on tissue regeneration in the rat bladder augmentation model.

To examine the histological differences in the inflammatory response and regenerative outcomes of distal vs proximal porcine small intestinal submucosa (SIS) grafts in the rat bladder, as SIS from distal small intestine yields reliable and reproducible bladder regeneration, while SIS from proximal portions of small intestine does not provide similar results.

Total and Partial Urogenital Mobilization: Focus on Urinary Continence

PURPOSE Total and partial urogenital mobilization procedures are the most common contemporary vaginoplasty surgeries for patients with congenital adrenal hyperplasia, urogenital sinus and cloacal anomalies. There is controversy regarding the urinary continence outcomes of these procedures. We reviewed the urinary continence outcomes of children who underwent total or partial urogenital mobilization at our institution and reviewed the literature to determine the continence rates of these procedures. MATERIALS AND METHODS We retrospectively reviewed 25 patients who underwent total or partial urogenital mobilization with a focus on postoperative continence status. Continence was defined as parental report of full toilet training with no accidents during the day and rare accidents (fewer than 2 per month) at night after age 3 years. RESULTS A total of 14 congenital adrenal hyperplasia, 5 urogenital sinus and 6 cloacal anomaly cases were managed by total (18) or partial (7) urogenital mobilization procedures with a mean followup of 4.41 years (range 0.21 to 12.1). In our cohort 21 of 22 patients (95.5%) were continent by age 3 years and there were no urinary complications. A total of 111 patients were identified in the literature with congenital adrenal hyperplasia or urogenital sinus, with 107 in 7 studies being continent (96.4%) by age 3 to 4 years. In 4 studies 32 patients were identified with cloacal anomalies who underwent total or partial urogenital mobilization, of whom 28 (87.5%) were continent by age 3 to 4 years. CONCLUSIONS There was no significant difference between total and partial urogenital mobilization procedures regarding postoperative urinary continence in our cohort and the literature. The urinary continence rate was 96% in the congenital adrenal hyperplasia/urogenital sinus group and 89.5% in the cloacal group.

The Current Management of the Neurogenic Bladder in Children with Spina Bifida

The urological care of the neurogenic bladder consists of 2 components: medical management with preservation of renal function and quality-oflife issues with achieving dryness and independence of bladder and bowel management. Both components are equally important for patients to live a healthy and fulfilled life. This report explores the diagnosis of the neurogenic bladder; quality-of-life issues that caregivers and patients should expect; the importance of primary care knowledge of the neurogenic bladder and treatment; surgical options; the transition of pediatric patients to adult care; and the importance of caregiver and patient understanding of their disease, treatment options, and responsibilities.

The use of tissue engineering and stem cells in bladder regeneration

Tissue engineering techniques for bladder regeneration have been applied successfully for many years in a variety of in vitro and in vivo models. But despite these rapid advances, to date, none of the tissue-engineered constructs could be used in human models due to inconsistent results of the described techniques in animal models. Three factors have been identified to influence the regeneration process: identification of the ideal scaffold, appropriate cell population for seeding and the optimal regeneration conditions necessary. Identifying the role of each component will help to unlock the complex regeneration mechanisms required to achieve consistent, reliable results that will allow transition of the technology into clinical practice. This review will discuss the role and applicability of the each factor and provide a future prospective on tissue engineering techniques for bladder regeneration.