Biomedical subjects
Publications and source records attributed to S A Koff.
Augmentation enterocystoplasty was used as an aid to reconstruction of the urinary tract and undiversion in 14 children with neurogenic bladder dysfunction. The long-term results have been excellent in children in whom an effective program of clean intermittent catheterization has been possible. The elements and the importance of the preoperative evaluation are discussed.
While the great majority of patients with neurogenic bladder and sphincter dysfunction have identifiable neurologic disease a small group will present with obvious genitourinary problems caused by not so obvious neurologic conditions. Thirteen such patients are presented, with a discussion of the ability of various urodynamic tests to predict the presence of significant neurologic disease.
The postnatal outcome of nine patients with the prenatal diagnosis of fetal hydronephrosis is reported. In only three of the nine cases was true obstructive hydronephrosis demonstrated, and in only one of these cases (11%) the patient might have benefited from decompressive surgery at the time of diagnosis of the abnormality. Twenty-nine additional cases from the literature are reviewed. It is concluded that a major deterrent to early fetal surgery is that most of the cases of obstructive hydronephrosis are identified too late in gestation.
The diuretic radionuclide urogram has been shown to be an effective method to discriminate obstructive from nonobstructive hydronephrosis in nontransplanted renal units. This test was evaluated in 9 renal transplant patients with suspected partial ureteral obstruction. An obstructed pattern in 2 patients was confirmed and relieved by an operation. Nonobstructed patterns in 7 patients were verified by long-term clinical followup and subsequent ancillary testing. Accurate in all 9 cases, this investigation appears to provide a safe, noninvasive method to diagnose suspected post-transplantation ureteral obstruction.
While it is obvious that the combination of elevated intravesical pressure, urinary tract infection, and reflux can be devastating to the upper urinary tracts, it has been appreciated only recently that a single mechanism, obstruction due to disorders of vesicourethral function, can produce all three pathologic phenomena in neurologically normal children. Advances in pediatric urodynamics now permit these patients to be recognized and their particular pattern of bladder and sphincter dysfunction to be diagnosed with certainty. Individualized therapy aimed at the underlying functional disturbance is often successful and may make surgical therapy unnecessary.
Explore the source record for details and available documents.
Abdominal wall electromyography, using sticky surface patch electrodes placed on the rectus abdominus muscles, was used during noninvasive urodynamic studies in 60 children to detect straining. Straining, which usually was imperceptible to the examiner, occurred in 64 per cent of neurologically normal children. Urodynamics identified detrusor-sphincter dyssynergia during straining to void but reverted to normal when the same children voided without straining. Because the urodynamic findings that characterize detrusor-sphincter dyssynergia are mimicked by straining and other common urologic entities, the potential for misdiagnosis is great unless some assessment of intra-abdominal pressure is made during neurourologic testing.
Explore the source record for details and available documents.
The ultrasonographic features of multicystic renal dysplasia in 15 patients (14 children, 1 adult) are described with emphasis on differentiating this condition from hydronephrosis. The most useful ultrasonographic criteria for identifying multicystic kidney include: (a) the presence of interfaces between cysts (accurate in 100% of cases); (b) nonmedial location of the largest cyst (100%); (c) absence of an identifiable renal sinus (100%); (d) multiplicity of oval or round cysts that do not communicate (93%); and (e) absence of parenchymal tissue (73%). The role and usefulness of radionuclide renal scanning are also discussed. Ultrasonography followed by nuclear scintigraphy appears to be a logical diagnostic sequence in the evaluation of neonates with flank masses. Excretory urography is of value in assessing the status of the uninvolved kidney.
Explore the source record for details and available documents.
A canine model with partial ureteral obstruction and progressive hydroureteronephrosis was utilized to validate and compare the accuracy of several diagnostic methods currently used to assess urinary tract obstruction. Tests of renal function and measurements of intrapelvic pressure were not helpful in following the progress of hydroureteronephrosis but did provide insight into the mechanisms by which incomplete ureteral occlusion impairs renal function. Serial intravenous pyelography, diuretic radionuclide urography, and perfusion pressure flow studies were frequently accurate in assessing obstruction, but each was subject to potential and, at times, regular misinterpretation. In applying the results of these laboratory studies to the problems of evaluating human hydroureteronephrosis, the clinician must recognize the pitfalls and limitations of these methods in order to ensure an accurate diagnosis of partial urinary obstruction.
Explore the source record for details and available documents.
Conventional radionuclide renography has been modified to include a pharmacologic intervention by administration of intravenous furosemide. The procedure is applied in patients with hydroureteronephrosis to distinguish dilated, nonobstructed systems from those with significant mechanical obstruction. Diagnostic patterns are derived from computer-generated time-activity histograms that depict the accumulation of radiotracer prior to diuresis and in response to diuresis. In dilated, nonobstructed systems, increased urine flow following diuresis causes a decline or "washour" of activity. In significantly obstructed systems, there is a failure of tracer activity to decrease in response to diuresis. The procedure is applied most commonly in suspected ureteropelvic junction and ureterovesical junction obstruction. The significance of residual urinary tract dilatation following corrective surgery also can be readily assessed. The major current limitation to the technique is poor renal function with inadequate response of urine flow to diuresis.
We reviewed the records of 255 children who have been managed by clean intermittent catheterization during the last 10 years to determine the incidence of bacilluria and upper tract changes. Bacteriuria was documented in 56 per cent of the children but febrile urinary tract infections occurred in only 11 per cent and fresh renal damage in 2.6 per cent. In the absence of vesicoureteral reflux bacilluria proved to be innocuous, since vesicoureteral reflux, progressive hydronephrosis or increasing parenchymal scarring did not develop. Bacteriuria in association with low grade reflux was rarely harmful and the reflux actually disappeared in up to 50 per cent of cases. However, bacteriuria in patients with high grade reflux was not an innocent phenomenon, since not only did the reflux tend to persist but pyelonephritis occurred in more than 60 per cent of the patients. In this latter group of patients reimplantation is an important therapeutic consideration if sterile urine cannot be achieved.
During the last 9 years 49 children with vesicoureteral reflux and neurogenic bladder dysfunction were treated with intermittent catheterization. Reflux spontaneously abated in 22 of 72 ureters (31 per cent). Reflux has been followed non-operatively in 17 ureters without renal deterioration. Reimplantation was successful in 24 ureters. In no instance was there ureterovesical obstruction or recurrence of the reflux and in none of the 12 unilateral reimplantations did contralateral reflux develop. Our experience suggests that children with reflux may be managed safely by intermittent catheterization, and that ureteroneocystostomy is reliable and effective in neurogenic bladder disease provided that bladder dysfunction is controlled.
Urethral mobilization is an adjunctive surgical technique for improving the position of the urethral meatus in a hypospadias operation. In patients with mild degrees of hypospadias and chordee the mobilized urethral meatus can be placed out onto the glans without constructing a neourethra. In more severe cases of hypospadias urethral advancement distally will reduce the length requirement for the neourethra. Mobilization of the urethra has been done in 21 children in conjunction with standard hypospadias repair techniques and the outcome has been highly successful for the majority.
We studied 37 children soon after ureteroneocystostomy using diuretic radionuclide urography to assess the patency of the ureterovesical junction. Postoperative obstruction was excluded correctly in 90 per cent of the patients. Transient ureterovesical obstruction occurred in 5 patients, identification of which was useful in assigning risk and in guiding followup studies. Because it is a safe, noninvasive and relatively low radiation test the diuretic radionuclide urogram proves to be an attractive alternative to the excretory urogram in the early and late followup of patients undergoing a ureterovesical junction operation.
Sixty-two children with 90 refluxing ureters and neurogenic bladder dysfunction were initially managed by clean intermittent catheterisation. The upper urinary systems demonstrated hydronephrosis and/or parenchymal scarring in 57 kidneys and were normal in 33. Each child was placed on low dose antimicrobials and followed nonoperatively unless there was evidence of a febrile urinary tract infection or upper tract deterioration at which point antireflux surgery or urinary diversion was performed. Our experience suggests that children with neurogenic bladders and reflux may be safely managed by clean intermittent catheterisation and that low or moderate degrees of reflux may actually disappear. If recurrent bacilliuria or febrile urinary infections are noted then ureteroneocystostomy is a reliable and effective treatment option in neurogenic bladder disease provided that the bladder dysfunction is controlled. Higher grades of reflux have proven more difficult to manage and in our experience the reflux has not spontaneously abated and frequently there are associated episodes of acute pyelonephritis and renal damage. Because of our success with reimplantation surgery, we now favour early ureteroneocystostomy in such circumstances. With effective management of the neurogenic bladder dysfunction with intermittent catheterisation permanent urinary diversion should only occasionally be necessary because of vesicoureteral reflux.