JBJohn W. Brock

John W. Brock

*This is an algorithmically generated author record based on publicly available information.

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John W. Brock has a total of 251 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Bladder Function After Fetal Surgery for Myelomeningocele

    by John W. Brock, Michael C. Carr, N. Scott Adzick, Pamela K. Burrows, John C. Thomas, Elizabeth A. Thom, Lori J. Howell, Jody A. Farrell, Mary E. Dabrowiak, Diana L. Farmer, et al.

    BACKGROUND: A substudy of the Management of Myelomeningocele Study evaluating urological outcomes was conducted. METHODS: Pregnant women diagnosed with fetal myelomeningocele were randomly assigned to either prenatal or standard postnatal surgical repair. The substudy included patients randomly assigned after April 18, 2005. The primary outcome was defined in their children as death or the need for clean intermittent catheterization (CIC) by 30 months of age characterized by prespecified criteria. Secondary outcomes included bladder and kidney abnormalities observed by urodynamics and renal/bladder ultrasound at 12 and 30 months, which were analyzed as repeated measures. RESULTS: Of the 115 women enrolled in the substudy, the primary outcome occurred in 52% of children in the prenatal surgery group and 66% in the postnatal surgery group (relative risk [RR]: 0.78; 95% confidence interval [CI]: 0.57–1.07). Actual rates of CIC use were 38% and 51% in the prenatal and postnatal surgery groups, respectively (RR: 0.74; 95% CI: 0.48–1.12). Prenatal surgery resulted in less trabeculation (RR: 0.39; 95% CI: 0.19–0.79) and fewer cases of open bladder neck on urodynamics (RR: 0.61; 95% CI: 0.40–0.92) after adjustment by child’s gender and lesion level. The difference in trabeculation was confirmed by ultrasound. CONCLUSIONS: Prenatal surgery did not significantly reduce the need for CIC by 30 months of age but was associated with less bladder trabeculation and open bladder neck. The implications of these findings are unclear now, but support the need for long-term urologic follow-up of patients with myelomeningocele regardless of type of surgical repair.


  • Diagnosis of constipation does not correlate with trans-abdominal ultrasound of rectal distention

    by Matthew D. Mason, Christina B. Ching, Douglass B. Clayton, John C. Thomas, John C. Pope, Mark C. Adams, John W. Brock, Stacy T. Tanaka


  • Development of upper tract stones in patients with congenital neurogenic bladder

    by Heidi A. Stephany, Douglass B. Clayton, Stacy T. Tanaka, John C. Thomas, John C. Pope, John W. Brock, Mark C. Adams


  • Contributors

    by Mark C. Adams, David M. Albala, Jennifer T. Anger, Elizabeth Anoia, Dean G. Assimos, Brian K. Auge, Demetrius H. Bagley, Linda A. Baker, Daniel A. Barocas, John M. Barry, et al.

  • Genitoplasty

    by John W Brock, John C Pope

  • Use of small intestinal submucosa for corporal body grafting in cases of severe penile curvature.

    by Bradley P Kropp, Earl Y Cheng, John C Pope, John W Brock, Martin A Koyle, Peter D Furness, Noel D Weigel, Rick W Keck, Kenneth A Kropp

    Small intestinal submucosa is a unique biomaterial that has been found to promote tissue specific regeneration in the urinary tract. We present our experimental and clinical experience with small intestinal submucosa (SurgiSis, Cook Biotech, Spencer, Indiana) for pediatric corporal body reconstruction. A total of 20 Fischer rats underwent implantation of a 7 x 3 mm. small intestinal submucosa graft following excision of an ellipse of tunica albuginea and 14 control animals underwent tunical excision with reimplantation of this autologous segment. The animals were euthanized, and the penis was sectioned and histologically studied at intervals of 1, 2, 4, 6, 16 and 24 weeks. In 15 pediatric patients small intestinal submucosa was used for corporal body grafting. The grafting procedure was performed along the ventral (hypospadias cases) or dorsal (epispadias cases) surface of the corporal bodies. The tunica albuginea was incised full thickness at the point of maximal curvature down to the cavernosal tissue and the defect was filled with a single layer of small intestinal submucosa. Measurements of the animal small intestinal submucosa grafts did not reveal significant graft contraction through 6 months. There was no graft expansion or ballooning after pharmacological induction of an artificial erection. Histologically, marked inflammation at 1 week precipitously decreased to a normal appearing tunica albuginea at 3 and 6 months. In all clinical cases small intestinal submucosa was found to be technically easy to handle. Mean followup is 14 months (range 5 to 26). All patients have a straight phallus as documented by observation of spontaneous erections or artificial erection at the time of stage 2 hypospadias repair. No complications occurred. Small intestinal submucosa demonstrates tissue specific regeneration properties in the rat and human tunica albuginea. It is an off-the-shelf material that is safe, technically easy to use and readily available.


  • The use of small intestinal submucosa as an off-the-shelf urethral sling material for pediatric urinary incontinence.

    by James R Colvert, Bradley P Kropp, Earl Y Cheng, John C Pope, John W Brock, Mark C Adams, Paul Austin, Peter D Furness, Martin A Koyle

    Use of autologous rectus fascia for urethral slings in the pediatric population has produced reliable and predictable results. However, the potential morbidity and complications associated with harvesting the autologous rectus fascia have driven efforts to find a reliable off-the-shelf material for urethral slings. Small intestinal submucosa is a collagen based material that has been shown to promote tissue specific regeneration in a variety of organs. We report the clinical experience at 4 institutions with small intestinal submucosa for urethral slings. A total of 20 patients 3 to 18 years old (mean age 8.7) received urethral slings using the commercially available form of small intestinal submucosa (STRATASIS, Cook Urologic Spencer, Indiana) via a sling suspension procedure from a suprapubic approach. The material was consistently uniform to work with and user-friendly. All 20 patients tolerated the procedure well with no intraoperative complications. Postoperative followup has ranged from 9 to 26 months (mean 13), and 14 (70%) patients are completely dry (85% in females and 43% in males). Of the 14 dry patients 13 are on intermittent catheterization and 1 female with epispadias voids spontaneously. This report is the largest and longest followup series using small intestinal submucosa as an "off the shelf" urethral sling material in children. These continence rates are equal to autologous fascia without additional morbidity of graft harvest.


  • Factors that influence outcomes of the Mitrofanoff and Malone antegrade continence enema reconstructive procedures in children.

    by Travis Clark, John C Pope, Mark C Adams, Nancy Wells, John W Brock

    Surgical techniques that provide adequate urinary and fecal continence in children with neurogenic bladder and bowel dysfunction are becoming increasingly used. We reviewed our experience and discuss factors that influence outcome. Between 1994 and 2000, 65 stomal procedures were performed in 47 patients. For the urinary continent catheterizable channel we used appendix in 60% of cases, a continent bladder tube in 20%, a Yang-Monti tube in 16% and ureter in 4%. For the antegrade continence enema continent catheterizable channel we used appendix in 85% of cases, a Yang-Monti tube in 5% and a cecal tube in 10%. In the 19 patients who underwent simultaneous Mitrofanoff and antegrade continence enema procedures the urinary continent catheterizable channel was appendix in 21%, a Yang-Monti tube in 32% and continent vesicostomy in 47%. Patients were divided into 2 groups based on compliance status. In addition, percentile body weight for age was evaluated. Stomal continence was achieved in 63 of the 65 cases (97%). Of the patients who underwent the antegrade continence enema procedure 95% achieved continence via the rectum. Except for ureter stenosis rates according to continent catheterizable channel type did not differ greatly, namely 19% for appendix, 11% for the Yang-Monti tube, 22% for the bladder tube, 50% for ureter and 0% for the cecal tube. Infectious complications developed in 16 patients and 4 had stones. The rates of infection (p = 0.004), stomal stenosis (p = 0.001) and revision (p = 0.004) were statistically lower in the compliant group and the stone formation rate showed a trend favoring the compliant group (p = 0.11). No significant difference was noted for incontinence. Percentile weight predicted a higher rate of stomal stenosis with the highest rate of stomal stenosis overall in the greater than 100th percentile group. The Mitrofanoff and antegrade continence enema procedures are reliable and effective. Proper patient selection and surgical technique with a tension-free anastomosis are essential. The choice of tissue for constructing the continent catheterizable channel is not as important as patient compliance, age and possibly body habitus. This report reinforces the importance of careful screening, and rigorous preoperative and postoperative teaching to achieve overall patient success.


    • 1 April 2002
      • Vol. 167  (4) , 1818-20

    Laparoscopic variability of the internal inguinal ring: review of anatomical variation in children with and without a patent processus vaginalis.

    by Randy G Nixon, John C Pope, Mark C Adams, George W Holcomb, John W Brock

    Diagnostic laparoscopy is routinely performed at our institution in children with a unilateral inguinal hernia to determine whether the contralateral processus vaginalis is patent. We reviewed the anatomical variability of the inguinal ring at laparoscopy in children with and without a hernia in various age groups. Since 1992, we have performed diagnostic laparoscopy in more than 1,500 children with a known inguinal hernia. Intraoperative imaging was correlated with clinical and operative findings to characterize the anatomical variability of the internal ring. The internal ring had many variations. The photographs presented show evidence of the progression from the flat closed ring to the widely open sac. Clefts and veils of peritoneum sometimes made determining the exact anatomy difficult. Experience shows that the various anatomical variations are associated with different pathological conditions. Characterization of the anatomical variability of the internal ring is essential for determining the patency of the processus vaginalis at diagnostic laparoscopy in children with a known inguinal hernia. We classified these variations in accordance with clinical and surgical findings.