eMedicine Specialties > Radiology > Pediatrics

Posterior Urethral Valve: Follow-up

Author: John S Wiener, MD, FACS, FAAP, Clinical Assistant Professor, Division of Urology, University of North Carolina at Chapel Hill; Associate Professor of Surgery and Associate Residency Program Director, Division of Urologic Surgery, Associate Professor of Pediatrics, Duke University School of Medicine
Coauthor(s): Anamaria Gaca, MD, Clinical Instructor, Division of Pediatric Radiology, Duke University Medical Center; Jeffrey Sekula, MD, Staff Physician, Chief Resident in Urology, Department of Urology, Duke University Medical Center
Contributor Information and Disclosures

Updated: Aug 7, 2007

Intervention

Prenatal intervention is essentially experimental and limited to a few centers. Options include percutaneous placement of a vesicoamniotic shunt, open fetal surgery, and fetal cystoscopic ablation. Significant complications may occur, resulting in maternal or fetal morbidity, as well as fetal loss. It is unclear whether prenatal intervention has a significant effect on the long-term prognosis of males with posterior urethral valves. Pulmonary function has been shown to benefit from the reversal of oligohydramnios, but no renal benefit has been noted.

In newborn males with suspected posterior urethral valves, ultrasonography should be performed in the first 24 hours to document bladder dilatation and changes in the upper tract. After the study, a 5F feeding tube may be placed as a urethral catheter. Some pediatric urologists favor a suprapubic catheter for the initial bladder drainage; however, urethral catheterization may be difficult because the valves obstruct retrograde passage of the catheter or the catheter may obliterate more flimsy valves, making later VCUG more difficult to interpret.

When VCUG is performed, ideally the urethral catheter should be removed during voiding to optimally demonstrate the valves. When the valves are diagnosed, the urethral catheter should then be replaced to continue decompression of the bladder. A serum creatinine level is determined to assess renal function. If the renal function is stable, transurethral valve ablation is performed through a cystoscope with a cold knife, electrocautery, or laser energy. If the serum creatinine level does not stabilize and if the upper tracts show no improvement, more drastic measures for bladder drainage may be required. Vesicostomy may be performed in such cases or if the urethra is too small to accept the small cystoscope. Routine performance of more proximal upper-tract diversion (pyelostomy, cutaneous ureterostomy) is reserved for rare circumstances.

The symptomatic older child usually undergoes cystoscopy for diagnosis with endoscopic ablation of the valves, if seen.

Medicolegal Pitfalls

  • Despite antenatal diagnosis of posterior urethral valves, severely affected male fetuses may die in utero or early in life. Early diagnosis may require the clinician to make recommendations regarding the potential viability and quality of life for an affected male fetus so that parents may make informed decisions regarding the elective termination of pregnancy. The upper gestational age limit for elective termination varies among states and countries.
  • Lack of definitive documentation of the valves on radiologic studies does not rule out their presence. Newborns with suspected lower tract obstruction and findings on VCUG should undergo decompression with a catheter until definitive therapy is performed. Ultimate renal function may improve as long as the obstruction is relieved early. Cystourethroscopy may ultimately be required to make the diagnosis.
  • Cystourethroscopy and endoscopic management may lead to urethral stricture formation. Incontinence of urine due to iatrogenic sphincter injury may not be seen until the boy reaches the normal age of continence. Retrograde ejaculation after puberty may be seen and be a cause of infertility.
  • Voiding dysfunction (urgency, frequency, and enuresis) is not uncommon in boys and typically improves spontaneously. If the symptoms are severe or do not improve, obstruction due to posterior urethral valve must be ruled out with VCUG. A missed diagnosis of obstruction may result in permanent bladder dysfunction, with possible renal failure.
 


More on Posterior Urethral Valve

Overview: Posterior Urethral Valve
Imaging: Posterior Urethral Valve
Follow-up: Posterior Urethral Valve
Multimedia: Posterior Urethral Valve
References
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References

  1. Young HH, Frontz WA, Baldwin JC. Congenital obstruction of the posterior urethra. J Urol, 3: 289-365, 1919. J Urol. Jan 2002;167(1):265-7; discussion 268. [Medline].

  2. Imaji R, Dewan PA. The clinical and radiological findings in boys with endoscopically severe congenital posterior urethral obstruction. BJU Int. Aug 2001;88(3):263-7. [Medline]. [Full Text].

  3. Williams CR, Pérez LM, Joseph DB. Accuracy of renal-bladder ultrasonography as a screening method to suggest posterior urethral valves. J Urol. Jun 2001;165(6 pt 2):2245-7. [Medline].

  4. Bani Hani O, Prelog K, Smith GH. A method to assess posterior urethral valve ablation. J Urol. Jul 2006;176(1):303-5. [Medline].

  5. Glassberg KI, Horowitz M. Urethral valve and other anomalies of the male urethra. In: Belman AB, King LR, Kramer SA, eds. Clinical Pediatric Urology. 4th ed. London, UK: Martin Dunitz Ltd; 2002:899-946.

  6. Krishnan A, de Souza A, Konijeti R, Baskin LS. The anatomy and embryology of posterior urethral valves. J Urol. Apr 2006;175(4):1214-20. [Medline].

  7. Salam MA. Posterior urethral valve: outcome of antenatal intervention. Int J Urol. Oct 2006;13(10):1317-22. [Medline].

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Further Reading

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Keywords

PUV, bladder outlet obstruction, posterior urethra, congenital obstructing posterior urethral membrane, COPUM, voiding dysfunction

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Contributor Information and Disclosures

Author

John S Wiener, MD, FACS, FAAP, Clinical Assistant Professor, Division of Urology, University of North Carolina at Chapel Hill; Associate Professor of Surgery and Associate Residency Program Director, Division of Urologic Surgery, Associate Professor of Pediatrics, Duke University School of Medicine
John S Wiener, MD, FACS, FAAP is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Surgeons, American Medical Association, American Urological Association, Society for Fetal Urology, Society for Pediatric Urology, and Society of University Urologists
Disclosure: Nothing to disclose.

Coauthor(s)

Anamaria Gaca, MD, Clinical Instructor, Division of Pediatric Radiology, Duke University Medical Center
Disclosure: Nothing to disclose.

Jeffrey Sekula, MD, Staff Physician, Chief Resident in Urology, Department of Urology, Duke University Medical Center
Disclosure: Nothing to disclose.

Medical Editor

Lori Lee Barr, MD, FACR, FAIUM, Clinical Associate Professor of Radiology, University of Texas Health Science Center in San Antonio; Clinical Assistant Professor of Radiology, University of Texas Medical Branch at Galveston; Member, Board of Directors, Austin Radiological Association; Consulting Staff, Seton Health Network, Columbia/St David's Healthcare System, Healthsouth Rehabilitation Hospital of Austin, Georgetown Hospital, St Mark's Medical Center, Cedar Park Regional Medical Center
Lori Lee Barr, MD, FACR, FAIUM is a member of the following medical societies: American Association for Women Radiologists, American College of Radiology, American Institute of Ultrasound in Medicine, American Roentgen Ray Society, American Society of Pediatric Neuroradiology, Association of University Radiologists, Radiological Society of North America, Society for Pediatric Radiology, Society of Radiologists in Ultrasound, Southern Medical Association, Texas Radiological Society, and Undersea and Hyperbaric Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.

Managing Editor

Kieran McHugh, MBBCh, Honorary Lecturer, The Institute of Child Health; Consultant Pediatric Radiologist, Department of Radiology, Great Ormond Street Hospital for Children, London, UK
Kieran McHugh, MBBCh is a member of the following medical societies: American Roentgen Ray Society and Royal College of Radiologists
Disclosure: Nothing to disclose.

CME Editor

Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute
Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray Society and Radiological Society of North America
Disclosure: Nothing to disclose.

Chief Editor

Eugene C Lin, MD, Consulting Radiologist, Virginia Mason Medical Center; Clinical Assistant Professor of Radiology, University of Washington School of Medicine
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, and Society of Nuclear Medicine
Disclosure: Nothing to disclose.

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