R. Dixon Walker

Injectable bioglass as a potential substitute for injectable polytetrafluoroethylene

Injectable polytetrafluoroethylene (Teflon) and collagen have inherent problems that may prevent their long-term success. In search of a different injectable biomaterial we confirmed in rabbits the safety of injected Bioglass particles suspended in sodium hyaluronate. A second study was performed testing the ability of the Bioglass suspension to increase urethral resistance in pigs. Bioglass particles in suspension have the potential to substitute for polytetrafluoroethylene or collagen in the treatment of urinary incontinence or vesicoureteral reflux.

Initial Experience with Extracorporeal Shock Wave Lithotripsy in Children

The clinical experience is presented of 4 United States centers at which extracorporeal shock wave lithotripsy was used for the treatment of renal calculi in 38 children 12 months to 16 years old. Patient characteristics, treatment specifics and followup data are detailed. Complete fragmentation of calculi was obtained in 97 per cent of those treated, with a 5 per cent complication rate. This experience demonstrates that with proper safeguards, extracorporeal shock wave lithotripsy can be performed safely and effectively in the pediatric population.

Treatment of Pediatric Urolithiasis Between 1984 and 1994

PURPOSE We report our experience with the management of pediatric urolithiasis during a 10-year period. Our aim was to assess the impact of new technology in the treatment of pediatric urolithiasis. MATERIALS AND METHODS We retrospectively reviewed the records of all patients up to age 18 years in whom urolithiasis was treated from 1984 to 1994. In 37 cases 24-hour urine collections were available for metabolic evaluation. RESULTS A total of 100 pediatric patients was treated for urolithiasis. Mean followup was 36 months. A total of 79 patients underwent 115 procedures for symptomatic urolithiasis and 21 were treated nonoperatively. In 42 patients structural anomalies of the urinary tract required additional management. Metabolic abnormalities in 48 patients included hypercalciuria in 19, defined as greater than 4 mg./kg./24 hours calcium by 24-hour urine collection. Only 24 of the 100 patients had no identifiable predisposing factors. Procedures included shock wave lithotripsy in 42 cases, basket extraction with or without ureteroscopy in 20, percutaneous nephrostolithotomy in 11 and litholapaxy in 12. Open surgery included cystolithotomy in 10 cases and other forms of open lithotomy in 15. Thus, open surgical removal was necessary in 1 of 5 cases. CONCLUSIONS Compared to the traditional mode of stone treatment, fewer patients required open surgery. Our results indicate that a comprehensive approach to the care of pediatric patients with urolithiasis requires attention to metabolic and structural abnormalities.

The Management of Posterior Urethral Valves by Initial Vesicostomy and Delayed Valve Ablation

We managed 32 neonates and infants with temporary vesicostomy and delayed valve ablation. The criterion on which successful management was gauged was estimated creatinine clearance. Renal failure or death occurred in 30% of the patients and 7% required transplantation. There was no apparent difference between our patients managed initially with vesicostomy and other series managed initially with valve ablation in preventing the complications of posterior urethral valves.

Management of the Failed Pyeloplasty

PURPOSE We present our experience with repeat surgery for persistent ureteropelvic junction obstruction. MATERIALS AND METHODS We retrospectively reviewed the records of patients who underwent pyeloplasty for ureteropelvic junction obstruction between 1984 and 1994, focusing on those who underwent repeat surgery for persistent ureteropelvic junction obstruction after initial pyeloplasty. RESULTS During the 10-year period 127 pyeloplasties were done by a single surgeon (R. D. W.). Three cases of persistent ureteropelvic junction obstruction occurred in this primary pyeloplasty series (success rate 97.6%). During the same period 9 other patients were referred to us from elsewhere for persistent ureteropelvic junction obstruction after initial pyeloplasty (total 12 patients). Ten patients underwent repeat pyeloplasty with a postoperative stent in place. Two patients needed nephrectomy at the initial repeat procedure and 1 of the 10 repeat pyeloplasty patients ultimately underwent nephrectomy. Six patients who had recurrent ureteropelvic junction obstruction were younger than 6 months at the time of the original pyeloplasty. Excessive urinary drainage was noted in 2 of our 3 cases of failed pyeloplasty. Thus, in 9 patients satisfactory resolution of obstruction was achieved by repeat pyeloplasty (salvage rate 75%). CONCLUSIONS Persistent ureteropelvic junction obstruction is an uncommon complication after pyeloplasty. Infants who undergo pyeloplasty may be more prone to persistent obstruction after pyeloplasty. Prolonged urinary drainage seems to be a harbinger of persistent ureteropelvic junction obstruction. Careful repeat pyeloplasty with attention to preservation of the blood supply and meticulous watertight anastomosis led to satisfactory resolution of ureteropelvic junction obstruction in 75% of the cases.

Prevention of Urethral Strictures in the Management of Posterior Urethral Valves

Our 28 patients with posterior urethral valves managed with transurethral resection have sufficient followup to evaluate the development of urethral strictures. Of these 28 patients 14 were less than 1 year old when the valves were resected and strictures developed in 7 (50 per cent). Of the 14 patients who were more than 1 year old when the valves were resected none had a stricture. Within the latter group was a subgroup of patients who were treated with early vesicostomy and later valve resection. None of these patients suffered a stricture. Our data indicate that stricture formation is high when valve resection is attempted in the neonate or small infant and can be prevented by primary vesicostomy and delayed valve resection.

COMPARISON OF SONICATED ALBUMIN ENHANCED SONOGRAPHY TO FLUOROSCOPIC AND RADIONUCLIDE VOIDING CYSTOGRAPHY FOR DETECTING VESICOURETERAL REFLUX

PURPOSE We compared sonicated albumin enhanced sonography to fluoroscopic and radionuclide voiding cystography for detecting vesicoureteral reflux. MATERIALS AND METHODS After obtaining informed consent we enrolled in our study 20 patients with known or suspected vesicoureteral reflux and no contraindications to intravesical sonicated albumin. All patients underwent albumin enhanced sonography, following which 10 patients each underwent radionuclide and fluoroscopic voiding cystography. Reflux was graded by the observing radiologist and urologist. RESULTS In 10 patients albumin enhanced sonography demonstrated reflux in 6 of the 7 (83%) ureters in which radionuclide cystography identified reflux. In 2 patients ultrasound studies were inadequate due to excessive movement during the procedure, and the patients were classified as unevaluable. In the remaining 10 patients 12 of 20 ureters (60%) were equal in the absence or presence of and degree of reflux on enhanced sonography and voiding cystourethrography. In 6 ureters voiding cystourethrography detected reflux more readily or revealed a higher grade of reflux. Two ureters had a higher reflux grade on enhanced sonography. No adverse effects were associated with intravesical sonicated albumin. CONCLUSIONS In experienced hands sonicated albumin enhanced sonography is safe for evaluating vesicoureteral reflux. It provides the simultaneous evaluation of renal contours, parenchyma and size in addition to bladder visualization. This new technique may prove to be useful as a followup study in patients with previously documented reflux or as a primary study for sibling screening.

Periurethral Polytetrafluoroethylene Injection Following Urethral Reconstruction in Female Patients with Urinary Incontinence

We present our results with periurethral polytetrafluoroethylene (Polytef) injection after urethral reconstruction in 20 female patients with urinary incontinence. These patients have failed previous urethral reconstructive procedures to cure incontinence, including Young-Dees-Leadbetter bladder neck reconstruction, transvaginal urethroplasty, transvaginal urethral plication and vesical flap urethroplasty. Of the patients 4 also underwent a bladder augmentation procedure. After polytetrafluorethylene injection 10 patients (50 per cent) were cured of the incontinence, 2 (10 per cent) had marked improvement from the preoperative condition, 5 (25 per cent) had definite improvement but still wear pads for protection and 3 (15 per cent) had no change from the preoperative condition. Bladder pressure recordings did not demonstrate a difference in results among patients with detrusor stability or instability. Periurethral polytetrafluoroethylene injection remains a valuable procedure in the management of persistent incontinence after bladder neck and urethral reconstruction.

The Repair of Urethral Fistulas Occurring after Hypospadias Repair

Abstract A successful method for repair of urethral fistulas occurring after correction of hypospadias has been developed. This repair was done in 14 patients with no fistula recurrence. The advantages of this technique include the decreased number of recurrent fistulas and the decreased hospital stay.

Vesicoureteral reflux update: effect of prospective studies on current management.

Until recemly, management decisions regarding vesicoureteral reflux (VUR) were based on a combination of bias and scattered objective data. These data provided some information about the natural history and pathogenesis of reflux but little as 1.0 whether medical or surgical treatment was the most advantageous. Management of VUR has been based on a series of premises. These include the following: VUR disappears spontaneously in many infants and young children but if still present at puberty is much less likely to resolve’- ‘; spontaneous resolution is lessened by severe grade of VUR, but can still occur even when associated with anomalies such as duplex ureter and paraureteral diverticulumJx5; sterile VUR does not appear to cause reflux nephropathy (RN), although it may be associated with minimal abnormalities of function such as alterations in concentrating ability.h,7 An exception to this may be that patients with sterile VUR and dysfunctional voiding with elevated bladder pressure have the potential for development of hydronephrosis and its associated effects on the renal parenchyma. Longterm antibacterials are well tolerated by children”; and surgical procedures to eliminate reflux are quite effective and indeed have traditionally set a standard against which medical management is measured.“~” Within the past decade four prospective studies have yielded data that provide a measure of how accurate our biases have been. These are the Birmingham Reflux Study, iL the Reflux study of the Southwest Pediatric Nephrology Group,13 and the American and European arms of the International Reflux Stud):”