Urinary tract obstruction in children. J Urol. 1995;154:1874-1883; discussion 1874-1883. [PMID: 7563375 DOI: 10.1097/00005392-199511000-00086]

Acute kidney injury due to bilateral ureteral obstruction in children

Bilateral ureteral obstruction in children is a rare condition arising from several medical or surgical pictures. It needs to be promptly suspected in order to attempt a quick renal function recovery. In this paper we concentrated on uncommon causes of obstruction, with the aim of giving a summary of such multiple, rare and heterogeneous conditions joint together by the common denominator of sudden bilateral ureteral obstruction, difficult to be suspected at times. Conversely, typical and well-known diseases have been just run over. We considered pediatric cases of ureteral obstruction presenting as bilateral, along with some cases which truly appeared as single-sided, because of their potential bilateral presentation. We performed a review of the literature by a search on PubMed, CrossRef Metadata Search, internet and reference lists of single articles updated to May 2014, with no time limits in the past. Given that we deal with rare conditions, we decided to include also papers in non-English languages, published with an English abstract. For the sake of clearness, we divided our research results into 8 categories: (1) urolithiasis; (2) congenital urinary tract malformations; (3) immuno-rheumatologic causes of ureteral obstruction; (4) ureteral localization of infections; (5) other systemic infective causes of ureteral obstructions; (6) neoplastic intrinsic ureteral obstructions; (7) extrinsic ureteral obstructions; and (8) iatrogenic trigonal obstruction or inflammation. Of course, different pathogenic mechanisms underlay those clinical pictures, partly well-known and partly not completely understood.

Transurethral incision of duplex system ureteroceles in neonates: does it increase the need for secondary surgery in intravesical and ectopic cases?

OBJECTIVE

To evaluate the relevance of ureterocele ectopia and associated reflux on the outcome of duplex system ureteroceles (DSU) after neonatal transurethral incision (TUI).

PATIENTS AND METHODS

The study included 41 neonates with a diagnosis of DSU; the ureterocele was ectopic in 24 (58%). Before TUI, vesico-ureteric reflux (VUR) was present in 13 lower moieties (32%) and seven contralateral ureters (17%). TUI was always performed within the first month of life. The follow-up and management were tailored for each patient from the findings at ultrasonography, voiding cysto-urethrography and renal scintigraphy. Results of intravesical and ectopic DSU were compared using Fisher's exact test.

RESULTS

TUI was effective in allowing ureteric decompression in all but one patient (2.4%). After TUI, VUR ceased in six lower ipsilateral moieties and in two contralateral ureters, while new VUR occurred in three contralateral kidneys. De novo VUR in the punctured moiety appeared in 13 cases (32%). Nine upper poles were not functioning. Twenty-one patients (51%) required secondary surgery. Ureteric reimplantation was indicated exclusively for reflux in the punctured moiety in only in two cases (5%), while in a further two iatrogenic reflux in a nonfunctioning upper moiety required total heminephro-ureterectomy. There was no significant difference between intravesical and ectopic ureteroceles in the occurrence of VUR in the punctured moiety, rate of nonfunctioning upper poles or need for secondary surgery.

CONCLUSIONS

About half of the patients with a DSU need secondary surgery, but this is rarely indicated for de novo reflux in the punctured moiety only. The need for secondary surgery was greater whenever there was associated reflux before endoscopic incision. There was no difference in the outcome of intravesical and ectopic ureteroceles and such distinction seems no longer to be of clinical relevance.

Predictive value of renal histological changes for postoperative renal function improvement in children with congenital ureteropelvic junction stenosis

BACKGROUND

The aim of this study was to evaluate the relationship between renal function, as measured by diuretic radionuclide renography, and the outcome of pyeloplasty. A study was designed to evaluate renal parenchymal biopsy specimens derived from children undergoing corrective surgery for ureteropelvic junction (UPJ) stenosis, and compare these to preoperative and postoperative renal function status.

METHODS

Thirty-five children with congenital unilateral UPJ stenosis were evaluated. In addition to all conventional diagnostic procedures for UPJ stenosis, differential renal functional (DRF) activity was assessed in each of these children by obtaining 99mTc diethylenetriaminepentaacetic acid renogram curves. All children underwent dismembered pyeloplasty, and follow-up renogram evaluation was conducted 6 and 12 months after surgical repair. Biopsy specimens from renal cortical regions obtained during the surgical correction of UPJ stenosis were evaluated, and changes in renal histology were graded from I to V according to their severity. Spearman's correlation test was used to compare the histological evaluation results and the basal, 6- and 12-month follow-up DRF findings. A Wilcoxon paired test was used to evaluate statistical differences between values.

RESULTS

The findings showed a positive correlation between the severity of histological changes and DRF activity. All kidneys (22) with a DRF activity value of < 40% preoperatively demonstrated at least grade III changes when biopsy specimens were examined. Of children with a DRF activity value > 40% (13), only three showed severe histological changes. Histological grades were correlated between basal (r = -0.4; P = 0.019), 6-month (r = 0.54; P = 0.002) and 12-month (r = 0.54; P = 0.02) findings. In the Wilcoxon paired test, there was a statistically significant difference between basal and 6-month values (P < 0.05), and also between basal and 12-month values (P < 0.01). There was no statistically significant difference between 6- and 12-month values (P > 0.20).

CONCLUSION

Comparative evaluation of postoperative renal function with DRF activity and renal parenchymal histological alterations revealed a close correlation in terms of renal function improvement potential following reconstructive surgery in children with UPJ stenosis.

Does the prenatal diagnosis of fetal urinary tract anomalies affect perinatal outcome?

A review of the literature is presented. Congenital renal and urinary tract anomalies are described, and the possible consequences of detecting them in utero are discussed. Prenatal detection of lethal anomalies affords the parents the option of terminating the pregnancy. If termination of pregnancy is not an acceptable option for the parents, the antenatal knowledge of lethal fetal anomaly helps the clinician to avoid unnecessary obstetric intervention, e.g., cesarean delivery for fetal distress. In certain cases of nonlethal renal and urinary tract anomalies, antenatal detection may influence both obstetric and postnatal management. It seems reasonable to anticipate that this might improve the prognosis of some children in terms of better preservation of kidney function. However, no scientific evidence is available to support such a statement. There are no randomized trials evaluating the outcome of congenital renal and urinary tract anomalies using different prenatal and postnatal diagnostic and therapeutic approaches. It is hoped that further research will lead to more rational antenatal and postnatal management protocols.