Long-term outcome of patients with obstructive uropathy

Limited surgical interventions in children with posterior urethral valves can lead to better outcomes following renal transplantation

There is currently no consensus as to the most appropriate means by which children with posterior urethral valves (PUV) are to be managed prior to transplantation. We compared (i) renal allograft survival and function in patients with PUV vs. those with non-obstructive causes of ESRD and (ii) graft outcomes in children who had limited interventions (Group 1) vs. those with more extensive urologic surgeries to decompress the urinary tract (Group 2). Twenty-six pediatric renal transplant recipients had ESRD due to PUV (Group 1, n = 16; Group 2, n = 10). The study group was compared to 23 matched controls with ESRD due to non-obstructive causes. Five yr patient and graft survival was similar in all patients with PUV (Groups 1 and 2) when compared to all other kidney recipients in the transplant program, 96.2% vs. 98.0% and 87.5% vs. 87.0%, respectively. Although calculated creatinine clearance (Ccr), was similar between the PUV group and controls for the first 4 yr, the 5 yr graft function was significantly lower in the PUV group. (53.7 +/- 15.7 vs. 70.2 +/- 21.0 mL/min/1.73 m2; p = 0.03). When the two PUV groups were compared, graft survival was equivalent, but graft function was significantly better at 5 yr in Group 1(60.4 +/- 10.8 vs. 33.8 +/- 9.3 mL/min/1.73 m2; p = 0.02). Thus, patients with PUV managed by a limited intervention approach of vesicostomy with delayed valve ablation or primary valve ablation, had better outcomes. When ESRD is virtually certain, additional pre-transplant surgeries affecting the urinary tract should be avoided.

Partial bladder outlet obstruction in the fetal rabbit

PURPOSE

We developed and tested an animal model of bladder dysfunction due to posterior urethral valves using partial outlet obstruction of the fetal rabbit bladder.

MATERIALS AND METHODS

Partial bladder outlet obstruction of fetal rabbit bladders was created on day 23 of gestation. Of the litter of 8 to 10 fetuses half was obstructed and the remainder served as controls. The doe and fetuses were sacrificed on day 30 of gestation (full term 31 to 32 days) and the fetal bladders were removed. Bladders that had doubled in weight from the average bladder weight of the control littermates were deemed sufficiently obstructed. Hematoxylin and eosin staining was performed and bladder strip response to 32 Hz. field stimulation, 200 microM. bethanechol and 200 mM. potassium chloride was measured.

RESULTS

Average body weight did not differ between the control and obstructed fetuses, indicating that surgery did not hinder fetal development. Hematoxylin and eosin staining confirmed smooth muscle cell hypertrophy and increased connective tissue in the obstructed bladders. Obstructed bladder strips responded significantly less to field stimulation, and significantly more to bethanechol and potassium chloride (mean plus or minus standard deviation 5.18 +/- 1.52, 6.29 +/- 1.3 and 10.15 +/- 2.18 x force per/100 mg. tissue, respectively)than control bladder strips (9.0 +/- 1.19, 3.5 +/- 0.46 and 6.16 +/- 1.33 x force per/100 mg. tissue, respectively) suggesting that denervation supersensitivity may have resulted from obstruction.

CONCLUSIONS

Partial outlet obstruction of the fetal rabbit bladder results in bladder hypertrophy and dysfunction but these changes are markedly different from those in the adult rabbit. Since rabbit fetal development is delayed compared to human fetal development, this model can be used to assess the consequences of posterior urethral valves.

Results of renal transplantation in boys treated for posterior urethral valves

The results of renal transplantation in boys treated for posterior urethral valves were evaluated and compared with a matched control group. Patient and graft survival was equal in both groups, although serum creatinine levels were slightly higher in the posterior urethral valves group. Postoperative complications, such as urinary tract infections, occurred more frequently in the posterior urethral valves group. Urodynamic evaluation was performed before transplantation in 11 of 20 patients. Adequate treatment of bladder dysfunction, such as poor compliance and/or hyperreflexia, is essential in diminishing the risks of secondary graft damage due to severe bladder dysfunction.

Renal function and upper urinary tract configuration following urinary diversion to a continent ileal reservoir (Kock pouch): a prospective 5 to 11-year followup after reservoir construction

We followed 17 patients who underwent urinary diversion via a continent ileal reservoir (Kock pouch) with yearly examinations for 5 to 11 years postoperatively. The examinations involved control of renal function and configuration of the upper urinary tract. In 5 patients the upper urinary tract had become dilated during followup and in 2 of these renal scarring also had developed. All 5 patients had endured temporary outflow obstruction or reflux (stricture, overdistension of the reservoir or a defective antireflux valve). Of the patients 1 had a marked decrease in renal function before the outflow obstruction was corrected by an operation. Routine blood chemistry study was normal and hyperchloremic acidosis was not noted in any patient. After peroral loading of 6 patients with ammonium chloride significant excretion of titratable acid was found in the urine. Substitution with vitamin B12 was given to 6 patients due to subnormal values in 2 and borderline values in 4.

Urologic disorders of immature cats

Numerous inherited and congenital disorders may affect the urinary system of cats. Those associated with clinical signs include renal dysplasia, renal hypoplasia, polycystic kidneys, ectopic ureters, urachal anomalies, and fistulas between the lower urinary tract and other structures. Acquired disorders of the urinary system of immature cats have been uncommonly recognized. Further studies are warranted to better define their prevalence in immature cats.

Drainage of the upper urinary tract as recorded with renography in patients with a continent urostomy (Kock pouch). An experimental study with various degrees of reservoir filling

The drainage from the upper urinary tract was studied by the use of renography in thirteen patients with well functioning continent ileal reservoirs for urinary diversion (Kock-pouch). Renography was performed with empty reservoir and with submaximal or maximal filling of the reservoir. The reservoir pressure was continuously recorded when renography was performed with a full reservoir. When the reservoir was empty renography showed normal drainage in all patients. When the reservoir was full the renography was normal in eight patients, these having a mean reservoir volume of 715 ml but showed a delay in five patients, these having a mean reservoir volume of 930 ml. When the renography was repeated in the latter group of patients with submaximal filling (mean reservoir volume 544 ml) there was no delay of the drainage phases on the renograms. In these five patients the considerable "over-filling" of the reservoir had resulted in volumes greatly exceeding the previously recorded maximal reservoir capacity and also in pressures exceeding considerably those usually recorded in ileal reservoirs. These results show that the pressure in the bladder substitute is of great significance for the drainage from the upper urinary tract and that the low pressure ileal reservoir under ordinary circumstances does not obstruct the flow from the upper urinary tract.

Ultrasonographic anatomy and diagnosis of fetal uropathies affecting the upper urinary tract. II. Nonobstructive uropathies

The authors describe the ultrasonographic anatomy and semiology of allowing detection of the main types of fetal non-obstructive uropathies. The results of the author's personal experience in this domain are compared to data from the literature. Differential features of the uropathies are given and the limitations and practical significance of prenatal and postnatal ultrasonography are discussed.

Obstructive uropathies diagnosed in utero. The postnatal outcome--a study of 43 cases

The ultrasonic antenatal diagnosis of obstructive uropathies is now common. This study of 43 cases in which the mean follow-up is more than 2 years already allows us to show the importance of early diagnosis. The importance of a thorough postnatal examination is emphasised as well as the importance of preventing urinary tract infection. Although relief of the obstruction in the neonatal period in many cases allows an excellent recovery due to the exceptional qualities of the urinary tract at this age, there remain serious uropathies associated with significant renal dysplasia, for which ultrasonic diagnosis in utero is still insufficient. The results obtained allow us to be optimistic regarding the prognosis for many of these children.

Prognostic features in infants with obstructive uropathy due to posterior urethral valves

The histories of 22 infants presenting during the first year of life with obstructive uropathy due to posterior urethral valves were analyzed to determine outcome and prognostic features. Mean patient age at the time of the initial surgical intervention was 39 days, and the mean duration of followup inclusive of renal function data was 5.8 years. One patient died (5 per cent) and one had end stage renal disease. The mean preoperative and postoperative serum creatinine concentrations during the initial hospitalization were 3.1 and 1.4 mg. per dl., respectively. Neither value was significantly predictive of the creatinine concentration at final followup. In contrast, the nadir creatinine value during the first year of life correlated significantly with final renal function. Children with nadir creatinine values less than or equal to 0.8 mg. per dl. by 12 months of age maintained creatinine levels less than or equal to 1.1 mg. per dl. at the time of final evaluation, whereas children with higher values during the first year of life were likely to have progressive renal failure. Of 19 final creatinine determinations 6 were normal and 5 exceeded 1.5 mg. per dl. Proteinuria, hypertension, renal biopsy findings, urinary infection, unilateral nephrectomy and type of surgery did not correlate significantly with functional outcome. Followup studies of longer duration are needed to determine the ultimate outcome of these patients, more than half of whom had some degree of renal insufficiency at final evaluation.