cases in utero with parenchymal compression and a nonfunc-tional kidney postnatally. This concept has a bearing ontreatment as it may be equally appropriate to decompress arelatively small subcapsular urinoma as to manage conser-vatively a large extrarenal extravasation. Imaging is unableto distinguish between these 2 situations with any certainty,but the rapid recovery of unilateral renal function followingdecompression may infer retrospectively the subcapsular na-ture of the extravasation.

The management of urinary extravasation with posteriorurethral valves is a short chapter in the long-term care ofthese patients and most of the decisions must be made earlywithout the benefit of individual kidney function assessmentby nuclear medicine. An algorithm for management is pre-sented in figure 2.

When faced with a newborn with posterior urethral valvesand extravasation obviously the initial move must be to drainthe urinary tract with a bladder catheter and observeprogress. If the clinical course is satisfactory and the ultra-sound appearance of the renal parenchyma is uncompro-mised then no intervention is required. There are some casesin which massive abdominal distention, either with ascites orretroperitoneal collections, demands decompression for respi-ratory or feeding difficulties, and this may be achieved byneedle aspiration initially with placement of a drainage cath-eter if fluid reaccumulates. The presence of persistent hyper-tension or obvious parenchymal compression on ultrasoundshould lower the threshold for intervention in keeping withthe concept of a subcapsular collection. Similarly, a progres-sive accumulation, reaccumulation or increase in plasma cre-atinine may indicate that drainage is appropriate.

There has been no real consistency in the management ofour cases during a 25-year period, which has seen the intro-duction of ultrasound and nuclear medicine. However, retro-spective analysis has allowed the formulation of an algorithmwhich acts as a framework for treatment, although manage-ment of these cases must always be individualized. The abil-ity to decompress under ultrasound control has reduced thehazards of intervention and facilitates the decision for activemanagement.

CONCLUSIONS

With a unilateral urinoma ipsilateral renal function isimpaired. Bilateral urinomas are associated with good renalfunction but urinary ascites alone has a poorer prognosis.This series of cases lends some support to the concept of earlyurinary tract decompression in utero in all cases of posteriorurethral valves by early vesicoamniotic shunting rather thanwaiting until extreme conditions occur, since extravasationsat lower pressures are associated with a much better renalprognosis.

REFERENCES

1. Greenfield, S. P., Hensle, T. W., Berdon, W. E. and Geringer,A. M.: Urinary extravasation in the newborn male with pos-terior urethral valves. J Pediatr Surg, 17: 751, 1982

2. Ahmed, S., Borghol, M. and Hugosson, C.: Urinoma and urinaryascites secondary to calyceal perforation in neonatal posteriorurethral valves. Br J Urol, 79: 991, 1997

3. Williams, D. I. and Eckstein, H. B.: Obstructive valves in theposterior urethra. J Urol, 93: 236, 1965

4. Fordyce, W.: Intrauterine ascites, its obstetrical significance andpathology. Tetratologia, 1: 61, 1894

5. Chantler, C. and Barratt, T. M.: Estimation of glomerular filtra-tion rate from the plasma clearance of 51-chromium edetic

acid. Arch Dis Child, 47: 613, 19726. Dubois, D. and Dubois, E. F.: A formula to estimate the approx-

imate surface area if height and weight be known. Arch InternMed, 17: 863, 1916

7. Lord, J. M.: Foetal ascites. Arch Dis Child, 28: 398, 19538. Moncada, R., Wang, J. J., Love, L. and Bush, I.: Neonatal uri-

nary ascites associated with urinary tract obstruction (urineascites). Radiology, 90: 1165, 1968

9. Garrett, R. A. and Franken, E. A., Jr.: Neonatal ascites: perire-nal urinary extravasation with bladder outlet obstruction.J Urol, 102: 627, 1969

10. Kay, R., Brereton, R. J. and Johnston, J. H.: Urinary ascites inthe newborn. Br J Urol, 52: 451, 1980

11. Mitchell, M. E. and Garrett, R. A.: Perirenal urinary extravasa-tion associated with urethral valves in infants. J Urol, 124:688, 1980

12. Krane, R. J. and Retik, A. B.: Neonatal perirenal urinary extrav-asation. J Urol, 111: 96, 1974

13. Fernbach, S. K., Feinstein, K. A. and Zaontz, M. R.: Urinomaformation in posterior urethral valves: relationship to laterrenal function. Pediatr Radiol, 20: 543, 1990

14. Cuckow, P. M., Dinneen, M. D., Risdon, R. A., Ransley, P. G. andDuffy, P. G.: Long-term function in the posterior urethralvalves, unilateral reflux and renal dysplasia syndrome. J Urol,158: 1004, 1997

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EDITORIAL COMMENT

The authors present a retrospective review of their experiencewith urinary extravasation in neonates with posterior urethralvalves. They divide the patients into groups according to the pres-ence or absence of ascites. They speculate that ascites without evi-dence of perirenal urinomas results from bladder rupture, an eventthat might require higher intraluminal pressure than forniceal rup-ture. Indeed the 3 boys in that category ended up with severelycompromised function. The hypothesis that isolated ascites withoutperirenal urinomas may result from bladder rupture is supported byother cases of bladder rupture in neonates with posterior urethralvalves.1, 2

Overall the presence of urinary extravasation seems to worsen theprognosis since overall 14 of 18 patients (78%) had a GFR of less than79 ml. per minute per m.2, a proportion much larger than thatreported in some series.3 This fact alone justifies, in my opinion, theproposed interventional approach to the treatment of neonates withclear evidence of extravasation, be it by draining the ascitic fluid orthe perinephric urinomas that do not quickly resolve with bladdercatheter drainage.

The statement that early vesicoamniotic shunt placement in allcases of posterior urethral valves should be investigated is not sup-ported by any of the data presented. However, I am in completeagreement that it represents the only currently available treatmentthat might improve the long-term prognosis of newborns with pos-terior urethral valves.

Ricardo GonzalezDepartment of SurgeryduPont Hospital for ChildrenWilmington, Delaware

1. Arora, P., Seth, A., Bagga, D., Aneja, S. and Taluja, V.: Sponta-neous bladder rupture secondary to posterior urethral valvesin a neonate. Indian J Pediatr, 68: 881, 2001

2. Claahasen-van der Griten, H. L., Monnens, L. A., Degier, R. P.and Feitz, W. F.: Perinatal rupture of the uropoietic system.Clin Nephrol, 57: 432, 2002

3. Denes, E. D., Barthold, J. S. and Gonzalez, R.: Early prognosticvalue of serum creatinine levels in children with posteriorurethral valves. J Urol, 157: 1441, 1997

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