A surgical model for normotensive chronic renal failure in the growing piglet

Studying the effects of chronic uremia in children has been hindered by the lack of a suitable large mammalian animal model with normotensive renal failure. We performed nephrectomy with simultaneous contralateral partial nephrectomy using a stapling device and absorbable staples in 22 domestic piglets. Up to 93% of the total renal mass could be excised by this method. A chronic uremic state was reproducibly developed and correlated with the percentage of renal mass excised. There were no associated postoperative complications with the stapled partial nephrectomy. Pigs with moderate renal failure had a significant decrease in growth compared to those with mild renal failure, which represents the successful development of a normotensive large mammalian animal model that could be used to study the effects of chronic renal failure and hyperfiltration during a state of rapid growth. In addition, this study confirms the successful use of a stapling device to perform partial nephrectomy.

Extravesical nondismembered ureteroplasty with detrusorrhaphy: a renewed technique to correct vesicoureteral reflux in children

We performed an extravesical nondismembered reimplant to correct surgically primary vesicoureteral reflux in 45 patients (65 renal units) between April 1989 and September 1990. Of the units 6 had grade I reflux, 16 grade II, 23 grade III, 14 grade IV and 6 grade V. Only patients with primary reflux were included in this study. The success rate was 100% for grades I to III, 92.9% for grade IV and 66.7% for grade V. Overall, the reflux was cured in 62 of the 65 operated renal units (95.4%) or 95.6% of the patients (43 of 45). Postoperative morbidity and complications were minimal. No cases of postoperative obstruction were detected on excretory urography 6 weeks postoperatively. Seven children (16%) suffered from transient inadequate bladder emptying as assessed by post-void ultrasound residual evaluations. This problem resolved spontaneously after a maximum of 4 weeks of clean intermittent catheterization. Compared to conventional transvesical technique, the discomfort related to bladder spasms during the postoperative period was subjectively decreased and patients had no prolonged hematuria.

Rapid development of an immunoblastic lymphoma and death in children following cadaveric renal transplantation

We report on three children who underwent cadaveric renal transplantation and subsequently developed an immunoblastic lymphoma, leading to death in two patients. The development of the lymphoma occurred following a multi-drug immunosuppression regimen ending with monoclonal antilymphocyte (OKT3) treatment for biopsy-proven cellular and vascular acute rejection. These patients represent three of 11 children who received OKT3 treatment for rejection in the last 18 months at this institution. Following the diagnosis of lymphoma, all three patients were treated by transplant nephrectomy, cessation of immunosuppression, and administration of intravenous acyclovir. The first two patients died at 4 days and 4 weeks, respectively, after the definitive diagnosis was made with widespread metastatic disease. The remaining child is a short-term survivor (13 months), free of demonstrable malignancy. Multidrug regimens for immunosuppression have a profound effects on T cell function. These effects, when combined with a primary infection by the Epstein-Barr virus, are implicated in the rapid development of the lymphomas and are responsible for the death of these two children.

Evaluation of factors contributing to mortality in pediatric renal transplant recipients

From 1969 to 1985, 303 renal allografts (290 cadaveric) were placed in 215 pediatric recipients. A review of actuarial recipient and allograft survival 2 years posttransplant showed good results in patients over 6 years of age (greater than 90% for patients, about 70% for allografts) but less satisfactory results in younger patients (75% for patients, about 45% for allografts). Thirty-nine patients died. Loss of allograft function preceded death in 67% of cases and was due to rejection (61%), renal vascular thrombosis (35%), and recurrence of original disease (4%). On retrospective analysis, 13 deaths might have been preventable with current diagnostic and therapeutic modalities. Allograft dysfunction from thrombosis occurs at a higher frequency in the young child and may be confused with rejection. Treatment of rejection without biopsy, overagressive treatment of a chronically failing graft, and failure to withdraw immunosuppressive therapy in face of infection are poorly tolerated in the very young recipient and are prominent causes of preventable mortality. Transplant nephrectomy and repeated attempts at transplantation are poorly tolerated in very young patients. Patient survival is very dependent on the success of the initial allograft in children.

Complications of surgical significance in pediatric renal transplantation

From 1969 to 1986, 303 renal allografts (290 cadaveric) were placed in 215 pediatric recipients. Twenty-three patients (7.6%) had renovascular complications and 16 (5.3%) had nonrenovascular complications. The overall incidence of surgically significant complications was 12.9%. Of these, 54% were felt to be of a technical etiology. The remainder were surgically significant in that their management necessitated operative intervention.

The ectopic ureterocele: a proposed practical classification based on renal unit jeopardy

A classification system for ectopic ureteroceles based on renal unit jeopardy is presented. This system has been found to be predictive of response to surgical reconstruction and is thus helpful in selecting the initial reconstructive approach. Specific guidelines for the selection of an appropriate surgical strategy are provided.

Omeprazole in post-gastrocystoplasty metabolic alkalosis and aciduria

The use of segments of stomach for bladder augmentation is gaining popularity in pediatric urology due to favorable muscular and secretory properties. However, in a renal failure patient who underwent gastrocystoplasty a high level of acid production within the bladder associated with persistent hypergastrinemia was noted leading to severe systemic metabolic alkalosis. This condition was unresponsive to standard acid-inhibiting or neutralizing therapies but it was treated successfully with omeprazole, a proton-pump inhibitor recently introduced for treatment of peptic ulcer disease.

Reduction in tumor burden allowing partial nephrectomy following preoperative chemotherapy in biopsy proved Wilms tumor

During the last 6 years a treatment protocol of radiographic staging along with percutaneous biopsy to establish a histological diagnosis has been used in 37 patients with Wilms tumor. Combination chemotherapy was given for 4 to 6 weeks before definitive surgical resection. In 9 patients tumor shrinkage was sufficient to permit preservation of a portion of the affected kidney(s). In stage V disease partial nephrectomy was accomplished in 5 patients. In 4 additional patients with unilateral disease downstaging also allowed partial nephrectomy. The radiological and histological changes that allowed this limited surgery are analyzed and compared.

Continence in bladder exstrophy: determinants of success

We evaluated 19 female and 18 male patients with bladder exstrophy, who had completed staged reconstruction, had required no further surgery and underwent urodynamic studies. Of the male population 61% were continent based on a significantly higher urethral continence length (25.8 +/- 6.4 mm., mean plus or minus standard error) and a higher urethral closing pressure (69.4 +/- 5.8 cm. water) compared to the incontinent male population (11.4 +/- 3.1 mm. and 43.4 +/- 4.6 cm. water). No significant difference was noted in the bladder capacity of these 2 groups. Of the female population 57.9% were continent. They also demonstrated a higher urethral continence length (21.1 +/- 4.4 mm.) and a higher urethral closing pressure (62.7 +/- 10.2 cm. water) compared to the incontinent female subjects (8.4 +/- 2.5 mm. and 32.7 +/- 6.9 cm. water). Moreover, those who were continent had a significantly higher bladder capacity (201.2 +/- 39.5 ml.) compared to those who were incontinent (84.3 +/- 23.6 ml.). These findings support a multifactorial mechanism in achieving continence but they suggest that of all the factors urethral length may be the most important.

Renal autotransplantation in children: a successful treatment for renovascular hypertension

Renovascular hypertension in children is not a common disease. With improved surgical technique the incidence of nephrectomy has decreased and renovascular reconstruction is currently the preferred method to manage this entity. Between 1977 and 1988, 21 patients with renovascular hypertension were treated at our hospital: 7 patients 6 to 16 years old underwent renal autotransplantation. Of the children 4 had unilateral and 3 had bilateral disease requiring bilateral autotransplantation. Autotransplantation was performed by anastomosis of each renal artery end-to-side to the common iliac artery. The renal veins were anastomosed end-to-side to the common iliac veins. The ureters were left intact in all but 1 patient who required a bench operation. Of the 4 patients who had a unilateral procedure 3 are cured and 1 is improved with a normal blood pressure on a small dose of antihypertensive medication. The 3 patients with bilateral autotransplants are cured. These results, with normalization of the blood pressure in 86% of the patients and improvement in blood pressure in 14% with a patency rate of 87%, are similar to other reported reconstructive modalities in children.

Magnetic resonance imaging of cystic, partially differentiated nephroblastoma

The magnetic resonance imaging (MRI) appearance of a cystic, partially differentiated nephroblastoma is described, together with pathologic correlation. The difficulty in reaching a correct preoperative diagnosis even with multimodal imaging techniques is emphasized. MRI is an adjunct to ultrasonography and may be superior to computerized tomography (CT) scan in the evaluation of a child with multiloculated cystic renal mass.

Lithostar extracorporeal shock wave lithotripsy in children

The Siemens Lithostar lithotriptor was used to treat 20 children (4 to 17 years old) with renal or ureteral calculi. Two patients had bilateral renal and 2 had ureteral calculi. Of 34 calculi treated 47% were in the renal pelvis, 29% in the lower calix, 12% in the upper calix, 3% in the middle calix and 9% in the upper ureter. Stone size ranged from 2 X 2 to 40 X 20 mm. and averaged 10 X 7 mm. Of the children 60% were treated while they were under neuroleptic anesthesia. No major complications were encountered. The 3-month rate free of stones after 1 treatment was 60% and increased to 80% with multiple treatments. The success rate, defined as being either free of stones or with residual fragments equal to or less than 4 mm. in diameter, was 95%. We conclude that lithotripsy with the Lithostar device in children, at least for the short term, is safe and effective.

Effects of the artificial urinary sphincter on prostatic development and sexual function in pubertal boys with meningomyelocele

Although sexual development in boys with meningiomyelocele may progress normally through puberty, the effects of surgical correction of incontinence by insertion of an artificial sphincter device around the bladder neck remain unclear. We studied 13 boys who received an artificial urinary sphincter before puberty and compared them to 12 age-matched pubertal controls with meningomyelocele. The prostate morphology was evaluated by means of transrectal ultrasonography, and we compared this finding, as well as sexual development, erectile function and seminal emissions between the 2 groups. Boys in both groups had similar development of secondary sexual characteristics and reported similar erectile function. Ultrasonography demonstrated an imprint of the sphincter cuff on the prostate but patients and controls had equal prostatic growth. In both groups an unexpected finding was the unexplained presence of sonolucent and sonodense lesions within the prostate glands. We conclude that transrectal ultrasonography is an excellent means of examining the prostate in pubertal boys with meningomyelocele. An artificial urinary sphincter placed around the bladder neck does not alter sexual development, function, prostatic growth or prostatic morphology.

Duplicate bladder exstrophy: a new variant of clinical and embryological significance

A case of duplicate exstrophy of a nature not previously encountered is reported, which we believe has important clinical and embryological implications. The patient presented with what appeared to be classical exstrophy. The inability to identify the ureteral orifices at operation led to the discovery of a previously unrecognized subjacent bladder of normal size and configuration except for a patulous bladder neck and associated epispadias. On excision of the duplicate bladder plate a coloniform projection was discovered that was lined with colonic mucosa. The surgical and potential embryological significance of this rare entity is described.

Submucosal injection of polyvinyl alcohol foam in rabbit bladder

Submucosal injection of either polytetrafluoroethylene (Teflon) or collagen has been used in the treatment of vesicoureteral reflux. Although the methods and principles of this treatment are effective, there are concerns regarding the safety and long-term effectiveness of these substances. We present a pilot study to explore the potential of an alternate substance (polyvinyl alcohol foam) for this treatment. Polyvinyl alcohol foam (Ivalon) particles measuring 150 to 250 mu. were injected submucosally into the bladder of New Zealand white rabbits. The bladder was examined macroscopically and microscopically at 1 and 2 weeks, and 1, 2 and 3 months after the injection. The particles created a raised lesion under the mucosa that was visible to the naked eye as late as 3 months after the submucosal injection. The particles remained in a submucosal location after 3 months. At 1 week after injection there was a foreign body giant cell response to the particles. At 3 months the giant cell response persisted and the particles were surrounded by a fibrotic reaction. There was little inflammatory response otherwise. These preliminary results indicate that polyvinyl alcohol foam may be suitable for subureteral injection in the treatment of vesicoureteral reflux.

Occult spinal dysraphism: clinical and urodynamic outcome after division of the filum terminale

A highly select group of 31 patients presenting with urinary incontinence failed to respond to conservative management and were found to have unstable bladders and spina bifida occulta. After thorough evaluation they were suspected of having neurogenic bladder dysfunction possibly due to a tethered cord. Following division of the filum terminale daytime incontinence resolved in 72%, urodynamic detrusor hyperreflexia disappeared in 59% and bladder compliance improved in 66% of the patients. The operation was well tolerated and did not result in any neurological complications. The clinical, radiological and urodynamic characteristics of these patients before and after treatment are reported.

High grade vesicoureteral reflux: analysis of observational therapy

Between 1981 and 1987, 300 patients with high grade (III, IV and V international classification) vesicoureteral reflux were treated at a single pediatric hospital. Only patients with primary vesicoureteral reflux were included in the study. The guiding principle during this period was that all patients with high grade vesicoureteral reflux would be observed on prophylactic antibiotics (observational therapy) and surgical correction would be reserved for specific indications. Of the 300 patients 132 received observational therapy alone and 168 required surgical correction for specific indications after varying periods of observation. In both groups the duration of persistent reflux was analyzed using a life-table method. In patients with grade V reflux we observed resolution in 3 patients whereas 23 required surgical correction. Of those patients in the observation group with grade IV reflux 83% had persistent reflux at 2 years and 70% still had reflux at 5 years. For those with grade III reflux the persistence rate was 83% and 50%, respectively. Neither age, sex nor side of reflux had a correlation with the rate of resolution. When tested grade of reflux correlated loosely (p = 0.07). During the period of observational therapy new renal scars developed in 23 patients (8%). We conclude that high grade vesicoureteral reflux can resolve in a minority of patients over a protracted interval. On the basis of this analysis, we advocate consideration of surgical correction in these patients after a 4-year period of observational therapy and for specific indications.

Factors predisposing to renal scarring: following staged reconstruction of classical bladder exstrophy

Preservation of renal function is one of the major goals of staged reconstruction of bladder exstrophy. In 68 exstrophy patients who have completed staged reconstruction, 10 (14.7%) have developed renal scarring. A multiple factorial analysis of these patients showed the following factors to be statistically related to the development of renal scarring: (1) one or more febrile urinary tract infections prior to bladder neck reconstruction (P less than .001); (2) failure to utilize antibiotic prophylaxis following initial bladder closure (P less than .005); (3) elevated urinary residuals greater than 50 mL (P less than .02); (4) a diagnosis of elevated urinary residuals greater than 6 months following the onset of continence (P less than .001); and (5) one or more febrile urinary tract infections following bladder neck reconstruction (P less than .005).

Emergency treatment and long-term follow-up of posterior urethral valves

Posterior urethral valves have a broad spectrum of clinical severity determined by the degree and reversibility of the long stepwise sequence of secondary pathology. Neonatal azotemia and severe bilateral reflux are particularly important negative prognostic factors. In the mild cases, valve ablation with or without delayed reconstruction is good therapy. In the very severe cases, our interpretation of all the clinical and experimental information now available suggests that the time interval and the level of decompression are extremely important. Achievement of consistent low caliceal pressure without stasis and infections should be achieved as soon as possible. We do not agree with the philosophy of "valve ablation and wait and see" for secondary reconstruction as applied to the severe cases. An analogous philosophy would be treating all respiratory infections as upper respiratory infections and applying aggressive appropriate therapy for pneumonia only if the patient does not respond clinically. However, all controversy aside, the management of neonatal infants with posterior urethral valves remains a difficult and challenging problem for us all. The real challenge will be to improve published management results to the point that the family faced with decisions regarding an in utero diagnosis of posterior urethral valves will have enough hope to continue the pregnancy.

Inguinal pathology and its association with classical bladder exstrophy

One hundred thirty-four cases of classical bladder exstrophy, managed at our institution, were reviewed. Fifty-six percent of the boys and 15% of the girls developed inguinal hernias over an average follow-up time-span of 10 years. Thirty-one percent of the patients with hernias underwent repair at the time of initial bladder closure. Forty-six percent of the patients who developed a hernia were diagnosed during the first year following their initial procedure. More than 50% of the individuals in the latter category presented with an incarcerated hernia, and required emergent management. Boys managed by staged reconstruction had a statistically significant risk of developing an inguinal hernia (P less than .001) compared with boys undergoing primary cystectomy and diversion. We believe the increased incidence of herniation with this congenital anomaly is secondary to a lack of obliquity of the inguinal canal, due to pubic diastasis along with an increased elevation of intraabdominal pressure following initial closure of the abdominal wall and bladder plate. To decrease the attendant morbidity of incarcerated hernias in this population, we stress the need for careful physical examination of the inguinal region and spermatic cord prior to surgery, along with repair of the patent processus vaginalis at the time of initial repair.

Percutaneous transluminal angioplasty for transplant renal artery stenosis in children

Severe hypertension developed secondary to renal artery stenosis in 11 of 229 children who received a renal allograft. Renal artery stenosis was suspected because of de novo development of hypertension or exacerbation of pre-existing hypertension, which was detected 1 to 24 months after transplantation. Selective renal angiography was performed 2 to 74 months after transplantation (mean 13 months). Follow-up was 1 to 8 years (mean 2.5 years). The stenosis involved the anastomosis in 5 patients and was distal to the anastomosis in 6. One graft had an arteriovenous malformation. Seven grafts were suitable for vessel dilation; percutaneous transluminal angioplasty was partially successful in 4 cases in which the stenosis occurred at the anastomosis. The remaining patients were treated with medical therapy alone and the grafts were not lost. Our findings suggest that strictures distal to the anastomosis rarely are amenable to percutaneous transluminal angioplasty and should be treated medically whenever possible. Strictures at the anastomosis respond to vessel dilation but antihypertensive medication also often is required. An operation should be reserved for patients who do not respond to these measures.

Influence of early function on long-term pediatric cadaveric renal allograft survival

The significance of early renal graft function on long-term transplant survival is controversial. From our pediatric renal transplant population we studied 151 children who had an initial cadaveric renal transplant, were dependent on dialysis before transplantation and were 5 to 19 years old at transplantation. We used dependence upon dialysis as the parameter for early graft function. There was a statistically significant difference in long-term graft survival between patients who were independent of and dependent on dialysis at 1 week and 1 month postoperatively. Our results show that early renal graft function is important for long-term graft survival. All efforts should be directed to obtaining early renal graft function by proper organ procurement, storage, operative technique and aggressive postoperative management.

The influence of HLA matching on renal allograft survival at a single pediatric center

Between January 1, 1969, and February 2, 1988, 331 pediatric renal transplants were performed at a single pediatric center. Of these 225 were first cadaveric allografts. Graft allocation was independent of the outcome of human lymphocyte antigen (HLA) matching. The results of class I antigen matching were analyzed in 224 transplants, and actuarial graft survivals were calculated. Class II antigen matching was analyzed in 80 patients from January 1, 1982, and submitted to the same analysis. HLA matching could not be demonstrated to be beneficial. It is proposed that any matching benefit is small and obscured in our series by the dominance of other factors.

Torsion of cavernous lymphangioma: an unusual cause of acute scrotum

A case of scrotal cavernous lymphangioma is described. Torsion of the pedicle resulted in an acute scrotal emergency that required surgical treatment.