Daniel B. Herz

EFFICACY OF ENDOSCOPIC SUBURETERAL POLYDIMETHYLSILOXANE INJECTION FOR TREATMENT OF VESICOURETERAL REFLUX IN CHILDREN: A NORTH AMERICAN CLINICAL REPORT

PURPOSE Subureteral injection of bulking agents is an accepted surgical treatment of vesicoureteral reflux in children. Polydimethylsiloxane, a silicone elastomer, is an ideal agent because of bulky consistency, lack of migration, minimal local inflammatory reaction and is safe in laboratory animals. We record our experience with endoscopic subureteral polydimethylsiloxane injection in children for vesicoureteral reflux. MATERIALS AND METHODS During a 2-year period 16 boys and 58 girls, with an average age of 8 years, with 112 refluxing ureters underwent endoscopic subureteral polydimethylsiloxane injection to treat vesicoureteral reflux. Vesicoureteral reflux was grade I in 8, II in 43, III in 50, IV in 10 and V in 1 ureter. Operative indications were breakthrough urinary tract infection in 29 children, nonresolution of reflux 38 and high grade reflux 7. All procedures were on an outpatient basis and performed with patient under general anesthesia. All children had a postoperative ultrasound and voiding cystourethrogram at 12 weeks. Followup was from 6 to 24 months. RESULTS Overall, reflux was corrected in 90 (81%) ureters and 56 (76%) children after a single injection. With repeat injection reflux was corrected in 101 (90%) ureters and 63 (85%) children. Correction by grade was 85%, 84%, 80%, 45% and 0% for grades I to V, respectively. With repeat injection correction was 100%, 92%, 90% and 55% for grades I to IV, respectively. There were no surgical complications. De novo contralateral reflux developed in 2 (3%) children. There were 3 (4%) children who required open ureteral reimplantation for failed injection. Detection of the polydimethylsiloxane implant by followup ultrasound was 89% sensitive and 86% specific for the correction of reflux. CONCLUSIONS Endoscopic subureteral polydimethylsiloxane injection is an effective treatment of vesicoureteral reflux in children. The procedure is safe with low associated morbidity. The presence of the polydimethylsiloxane implant can be documented accurately by ultrasound, and there is a strong correlation between implant stability and correction of reflux.

A prospective randomized clinical trial to evaluate methods of postoperative care of hypospadias

PURPOSE Hypospadias repair is a common operation performed by pediatric urologists. Perhaps the greatest variable and source of controversy of postoperative care is the surgical dressing. We hypothesized that using no dressing would achieve surgically comparable results to those traditionally achieved by a postoperative dressing and it would also simplify postoperative parent delivered home care. Accordingly we designed a prospective randomized clinical trial to compare surgical outcome and postoperative care after hypospadias repair in boys with no dressing and those who received 1 of the 2 most common types of dressing. MATERIALS AND METHODS In a 12-month period 120 boys with an average age of 2.2 years underwent primary 1-stage hypospadias repair at a single center with 4 participating surgeons. Repair was performed in 60 boys with proximal and 60 with distal hypospadias on an outpatient basis. Ethics and Internal Review Board approval, and informed consent were obtained. Boys were then prospectively randomized to receive no dressing, an adhesive biomembrane dressing or a compressive wrap dressing. Comprehensive instructions on postoperative care were distributed to all families and a questionnaire was distributed to the parents at the initial followup. Surgical outcome was evaluated and questionnaire responses were analyzed. Fishers exact test was done to test the significance of differences in surgical outcomes and questionnaire responses. RESULTS A total of 117 boys completed the prospective randomized trial. Surgical staff withdrew 3 cases from randomized selection to place a dressing for postoperative hemostasis. We obtained 101 questionnaires for response analysis. The type or absence of the dressing did not correlate with the need for repeat procedures, urethrocutaneous fistula, or meatal stenosis or regression. Analysis revealed less narcotic use in the no dressing group and fewer telephone calls to the urology nurse, or on-call resident and/or fellow. These findings were statistically significant. In addition, there were more unscheduled visits to the urology clinic, emergency room or primary physician office by boys with than without a dressing. Furthermore, 29% of the parents were not psychologically prepared to remove the dressing and 12% were so reluctant that the dressing was removed at the urology outpatient clinic. CONCLUSIONS The surgical outcome and rate of adverse events or complications were not compromised without a postoperative dressing. An absent dressing simplified postoperative ambulatory parent delivered home care. We recommend that dressings should be omitted from routine use after hypospadias repair.

TUNICA VAGINALIS FOR CORRECTING PENILE CHORDEE IN A RABBIT MODEL: IS THERE A DIFFERENCE IN FLAP VERSUS GRAFT?

PURPOSE We compared tunica vaginalis applied as a flap versus a graft for covering defects in the ventral tunica albuginea in a rabbit model. MATERIALS AND METHODS We used 18 New Zealand White rabbits in the study. The urethra was mobilized off of the corpus cavernosum. A defect was created in the ventral aspect of the tunica albuginea by excising a 1 x 0.5 cm. rectangular area. The defect was covered by the testicular surface of tunica vaginalis as a vascularized flap in 9 animals and as a graft in 9. At 2, 6 and 12-week intervals 3 animals per group were sacrificed. Transverse sections of the penis at the repair site were stained with hematoxylin and eosin, and Massons trichrome for microscopy. RESULTS Autopsy revealed no contracture in any of the tunica vaginalis flaps. In contrast, the tunica vaginalis grafts had contracted by a mean of 22% (range 20% to 25%) at 2, 38% (range 30% to 44%) at 6 and 42% (range 38% to 48%) at 12 weeks. Microscopic examination of the tunica vaginalis flaps showed evidence of an intact blood supply and viable cremasteric muscle layer but no evidence of necrosis. Collagen remodeling and maturation was noted at 12 weeks. In tunica vaginalis grafts there was evidence of necrosis of all tunica vaginalis layers at 2 weeks with granulation tissue and active fibrosis at the periphery. At 6 and 12 weeks most necrotic tissue was replaced by fibrosis. Osseous metaplasia was identified in 1 graft at 12 weeks. CONCLUSIONS The optimal use of tunica vaginalis for correction of chordee is as a flap rather than as a free graft. Grafts were associated with significant necrosis and contracture, of which neither was associated with flaps.

Healing of unstented tubularized incised plate urethroplasty: an experimental study in a rabbit model

To develop a rabbit model to study the temporal healing taking place after an unstented tubularized incised plate urethroplasty (TIPU).

High resolution ultrasound characterization of early allograft hemodynamics in pediatric living related renal transplantation

PURPOSE Allograft vascular thrombosis occurs in 5% to 10% of pediatric renal transplants. The hemodynamics of renal allograft immediately after implantation is unclear. High resolution Doppler ultrasound of the renal allograft performed in the operating room after incision closure is an effective and objective method to advance our understanding of baseline renal allograft hemodynamics, and identify unsuspected vascular complications early enough to ensure prompt surgical repair. MATERIALS AND METHODS Between September 1998 and July 2000 high resolution, color power Doppler ultrasound was prospectively performed on 21 living related renal transplants in the operating room immediately after incision closure. Each ultrasound described allograft anastomotic blood flow, direction of diastolic flow, parenchymal perfusion and resistive indexes. RESULTS There were 20 (95%) allografts with good power Doppler perfusion that had satisfactory immediate function with no vascular complications at 9 to 26-month followup. Initially, anastomotic turbulence was described in 15 (71%) allografts, and resistive indexes were abnormal in 8 (38%). Turbulence and abnormal resistive index normalized in all allografts by 1-month followup. Ultrasound of 1 allograft identified unsuspected poor perfusion and reversal of diastolic flow in the operating room after incision closure. In another allograft in which a 4-hour post-transplant ultrasound was compared with the baseline study in the operating room an unsuspected thrombosis of the right common iliac vein was confirmed. CONCLUSIONS Good parenchymal perfusion and forward diastolic flow after renal reperfusion correlated well with immediate graft function. Initial turbulence and abnormal resistive index in the presence of favorable perfusion are misleading and not independent predictors of graft function. Ultrasound performed in the operating room identified 2 unsuspected major vascular complications facilitating prompt surgical correction.