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Pediatrics: Surgery > Urology
Urethral Anomalies and Urethral Prolapse
Article Last Updated: Sep 15, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 10
Author: Jyoti Upadhyay, MD, FAAP, Associate Professor of Urology, Chief, Section of Pediatric Urology, Department of Urology and Pediatrics, State University of New York Upstate Medical University; Director of Pediatric Urology, University Hospital
Jyoti Upadhyay is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Medical Association, American Urological Association, Endourological Society, and Society for Pediatric Urology
Coauthor(s):
Carlos A Angel, MD, Associate Professor of Pediatrics, Division of Pediatric Surgery, University of Tennessee School of Medicine; Consulting Staff, East Tennessee Children's Hospital, East Tennessee Pediatric Surgery Group
Editors: Bartley G Cilento, Jr, MD, Instructor, Department of Surgery, Division of Urology, Children's Hospital of Boston and Harvard Medical School; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Harry P Koo, MD, Chairman of Urology Division and Director of Pediatric Urology, Virginia Commonwealth University; Professor of Surgery, VCU School of Medicine, Medical College of Virginia; Director of Urology, Children's Hospital of Richmond; Daniel Rauch, MD, FAAP, Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine; William J Cromie, MD, MBA, President and Chief Executive Officer, Health Care, Capital District Physicians' Health Plan
Author and Editor Disclosure
Synonyms and related keywords:
urethral anomalies, urethral prolapse, lacuna magna, sinus of Guérin, urethral duplication, epispadiac urethral duplication, hypospadiac urethral duplication, Y-type urethral duplication, anterior urethral valves, urethral diverticula, anterior urethral diverticula, megalourethra, scaphoid megalourethra, fusiform megalourethras, urethral diverticulum, urethral polyps, congenital urethral polypse, Cowper duct cysts, urethral prolapse, prune belly syndrome, cloacal malformations, vertebral, anal, cardiac, tracheal, esophageal, renal, limb, VACTERL
Background
This article discusses a variety of urethral anomalies observed in male infants and children and the distinct entity of urethral prolapse in prepubescent females. Urethral prolapse is a protrusion of urethral mucosa beyond the urethral meatus and generally occurs in prepubertal African American girls or in postmenopausal white females. This article discusses the pediatric entity of urethral prolapse.
Similarities in the modes of presentation of these conditions are striking, underscoring the importance of a thorough history, physical examination, and radiologic imaging with careful and complete cystourethrography, sonography, or endoscopy.
Pathophysiology
Lacuna magna
Lacuna magna, also known as sinus of Guérin, is a dorsal diverticulum in the roof of the fossa navicularis presenting either as a pit or a 4- to 6-mm sinus, dorsal and parallel to the urethra. This lesion is thought to arise embryologically from an incomplete fusion between the ingrowing ectoderm at the tip of the penis and the glandular urethra.
Urethral duplications
Urethral duplications are rare anomalies characterized as epispadiac, hypospadiac, and Y-type. They may be either complete, if venting externally, or incomplete, in which case the connection with the urinary tract is variable. In complete duplications the patient may void with a double stream. Epispadiac duplications usually are associated with significant dorsal curvature of the penis. The most common type of urethral duplication is the Y-type; individuals with Y-type urethral duplication have an orthotopic meatus and a perineal meatus, through which most of the urine passes. The etiology of these conditions is unknown.
Anterior urethral valves
Anterior urethral valves are rare anomalies, occurring 7-8 times less frequently than posterior urethral valves (PUV), but with consequences just as devastating. These lesions can occur anywhere in the anterior urethra, and the valve mechanism usually is formed by an associated diverticulum; isolated valves formed by cusps or irislike diaphragms also have been reported. The diverticulum has been postulated to arise from incomplete formation of the ventral corpus spongiosum, an incomplete urethral duplication, or a congenital cystic dilation of a periurethral gland. However, these lesions are embryologically distinct from the much more common PUV.
Megalourethra
Megalourethra can be described as a urethral diverticulum affecting the entire penile urethra. Two types, scaphoid and fusiform, have classic descriptions. Scaphoid megalourethras have an absence of corpus spongiosum, whereas fusiform megalourethras lack both spongiosum and corpora cavernosa. Often associated with lethal congenital anomalies, fusiform megalourethras are present in some stillborns, and this finding therefore has more academic than clinical pertinence. Temporary obstruction during early development may be an etiologic factor in fusiform megalourethra. In the scaphoid type, in which failure of development of erectile tissue is present, a mesenchymal defect is suggested akin to what is observed in the prune belly syndrome.
Anterior urethral diverticula
Anterior urethral diverticula occur in males and may involve the proximal part of the penile urethra and the distal part of the bulbous urethra. An underlying defect in the spongiosum is suggested, as observed in scaphoid megalourethra, or, possibly, these lesions may result from the rupture of a periurethral cyst or a partial duplication of the urethra.
Urethral polyps
Urethral polyps are rare anomalies, characterized as benign urothelial-lined masses attached to a fibrovascular stalk arising from the verumontanum, presenting almost exclusively in boys. Urethral polyps' association to the verumontanum suggests the embryologic persistence of müllerian structures. Some of these polyps, diagnosed later in life, may represent acquired lesions.
Cowper duct cysts
Cowper duct cysts involve the Cowper glands, 2 paired periurethral structures located in the urogenital diaphragm, which are drained by ducts measuring 2-3 cm long that empty into the bulbous urethra through 2 small, flush openings. These glands, homologous of the Bartholin gland in the female, secrete a clear fluid that functions as a lubricant and a coagulation factor for semen during ejaculation. Abnormalities of these glands and their ducts may result from obstruction and, less frequently, trauma and infection.
Urethral prolapse
Urethral prolapse is the complete protrusion of the urethral mucosa beyond the meatus. This is an uncommon condition observed particularly in prepubertal African American and Latin American girls. Increased incidence has been reported in children from the lower socioeconomic strata. This condition is thought to result from poor attachments between the longitudinal and circular, oblique, smooth muscle layers and the mucosa of the urethra in association with recurrent episodes of increased intraabdominal pressure. Other contributing factors such as trauma, malnutrition, urinary and vaginal infections, and urethral mucosa redundancy have been postulated in the etiology of this condition.
Frequency
International
Most conditions discussed in this article are infrequent or rare. Although the dorsal urethral diverticulum in the roof of the fossa navicularis (ie, lacuna magna) may be present in approximately 30% of examined boys, this condition rarely is symptomatic. Urethral duplications are rare; only 150 cases had been reported in the literature prior to 1986. A ratio of the incidence of anterior urethral valves relative to that of PUV is 1:8; PUV occurs in 1 in 8000 to 1 in 25,000 live male births. Fewer than 50 cases of megalourethra had been reported in the literature by 1993, with the scaphoid type more common. Megalourethras often have been associated with other severe anomalies, such as the prune belly syndrome, cloacal malformations, and the vertebral, anal, cardiac, tracheal, esophageal, renal, limb (VACTERL) association of congenital anomalies.
Diverticula of the anterior urethra are uncommon but are the second most common form of congenital urethral obstruction, after PUV, in infants and children. Both Cowper duct cysts and congenital urethral polyps are quite rare. Urethral prolapse has an estimated incidence of 1 in 3000 and is most common in young African American or Latin American girls.
Mortality/Morbidity
- Morbidity of the sinus of Guérin (ie, lacuna magna) is limited to those few symptomatic patients who present with dysuria, hematuria, or hematospermia.
- While most patients with incomplete urethral duplications are asymptomatic, patients with complete duplications can present with urinary obstruction, incontinence, infection, or double stream.
- Epispadiac duplications are associated with a significant dorsal curvature of the penis. In general, associated upper urinary tract anomalies are infrequent but should be investigated.
- In at least 50% of patients with anterior urethral valves, associated hydronephrosis or vesicoureteral reflux (VUR) is present.
- Although most attention has been focused on PUV, anterior valves can be just as obstructing and devastating, in some cases leading to chronic or end-stage renal failure.
- Prognosis of patients with megalourethra depends on the number and severity of the associated anomalies. Often, patients with fusiform megalourethras have associated lethal congenital malformations.
- Urethral diverticula, polyps, and Cowper duct cysts are benign conditions that may cause urinary retention, hematuria, irritative voiding symptoms, dribbling, or urinary tract infections (UTIs). Because these lesions may be obstructive, evaluation of the upper urinary tracts is essential.
- Urethral prolapse may result in vaginal discharge, spotting, or bleeding and, if unattended, can lead to necrosis of the prolapsed portion of the urethra.
Race
Prepubertal African American and Latin American girls have the highest incidence of urethral prolapse.
Sex
Urethral prolapse is the only condition discussed in this article that affects females.
Age
Urethral prolapse in the pediatric population occurs most commonly in prepubertal African American girls.
History
Because lacuna magna, anterior urethral valves, congenital urethral polyps, and Cowper duct cysts present with quite similar complaints, careful consideration of these urethral anomalies, along with a complete physical examination and appropriate imaging studies, are required to reach the correct diagnosis.
- Lacuna magna: Children with lacuna magna can report intermittent postvoid spotting, hematuria, dysuria, or severe pain in the vicinity of the glans during voiding.
- Urethral duplications: Most patients with incomplete urethral duplications are asymptomatic, but those with complete duplications may complain of urinary incontinence, discharge from the accessory urethra, double urinary stream, or symptoms of UTIs.
- Anterior urethral valves
- Infants present with severe outlet obstruction.
- Older children present with irritative voiding symptoms, weak stream, incontinence, dribbling, or UTIs. Emptying of the valve diverticulum or overflow incontinence may cause dribbling.
- Diverticula of the anterior urethra also can present in infancy with urinary obstruction or retention and, later, as UTIs or dribbling.
- Congenital urethral polyps: In children, symptoms include intermittent bladder obstruction, hematuria, dysuria, and UTI.
- Cowper duct cysts: These are manifested by hematuria, passage of mucous plugs, dysuria, intermittent obstructions, and postvoid dribbling. These symptoms become more apparent in adolescent males.
- Urethral prolapse: This is the only condition discussed in this article that affects females. Patients usually present with vaginal bleeding, spotting, dysuria, urinary frequency, introital pain, and, occasionally, urinary incontinence or retention.
Physical
Many of the conditions discussed in this article may be suggested by history; however, the anomalies may not be obvious on physical examination. Some of these conditions are clearly evident.
- In patients with urethral duplications, dorsal curvature of the penis (in the epispadiac type), double stream, or multiple meatus can be present.
- In children with anterior urethral valves and congenital urethral diverticula, the urethra may bulge while voiding and the stream may be weak.
- In boys with fusiform megalourethra, the penis is flabby and soft due to the absence of corpora cavernosa, and the urethra balloons during micturition. Unfortunately, fusiform megalourethra is usually an autopsy finding since this condition often is associated with stillbirths.
- Occasionally, urethral polyps prolapse through the meatus, or a perineal mass can be palpated in patients with a Cowper duct cyst.
- The physical findings in girls with urethral prolapse are quite striking. In these girls, a doughnut-shaped anterior vulvar mass completely surrounding the urethra is pathognomonic. The demonstration of the meatus in the center of the edematous tissue is important for diagnosis.
- This mass appears as an edematous fleshy rosette that may become ulcerated, necrotic, or gangrenous.
- Finding the urethral meatus is critical in making the diagnosis of urethral prolapse. The meatus can be located by inspecting the urethra, placing a Foley catheter, or watching the child void.
- Urethral prolapse is the only condition in which a circumferential mass surrounding the urethra can be found.
Causes
See Pathophysiology.
Child Abuse & Neglect: Sexual Abuse
Rhabdomyosarcoma
Rhabdomyosarcoma: Surgical Perspective
Ureteral Duplication, Ureteral Ectopia, and Ureterocele
Urethral Anomalies and Urethral Prolapse
Urinary Tract Infection
Voiding Dysfunction
Other Problems to be Considered
Prune belly syndrome Urinary incontinence Vaginal tumors (rhabdomyosarcoma) Dysfunctional vaginal bleeding Vaginitis Bladder rhabdomyosarcoma Urethral papilloma
Lab Studies
- Perform a complete urinalysis and urine culture for any child who presents with symptoms suggestive of a UTI.
- Hematuria in the absence of infection and the evaluation of urinary incontinence are beyond the scope of this article, but they merit thorough investigation (see Hematuria, Urinary Incontinence).
- In cases of urethral prolapse, taking a culture from the prolapsed mass or from any associated vaginal discharge may be useful.
Imaging Studies
- Study all patients with culture-proven UTIs with a voiding cystourethrogram (VCUG) and a renal and bladder ultrasound.
- In the absence of UTIs, most suspected urethral lesions can be documented with a VCUG or a retrograde urethrogram (RUG).
- Evaluation of the upper tracts with sonograms, nuclear scans, or intravenous pyelograms is particularly important in patients with anterior urethral valves, urethral duplications, megalourethras, urethral diverticula, polyps, or Cowper duct cysts because various degrees of obstructive uropathy may be present.
- In patients with megalourethras and urethral duplications, additional imaging studies may be necessary due to the high incidence of associated anomalies.
- Patients with urethral prolapse do not require further evaluation of their urinary tracts. However, if the diagnosis is in question, performing a bladder ultrasound to exclude a bladder rhabdomyosarcoma is reasonable.
Procedures
- Cystoscopy can be used to clarify a diagnosis or for therapeutic purposes.
Medical Care
- Treatment of urethral prolapse ranges from conservative therapy (eg, applications of antibiotic ointments, estrogen creams, sitz baths, herbal remedies, oral antibiotics) to a variety of surgical techniques. While some medical professionals have advocated conservative measures, the author feels that these measures should be used in the milder cases of urethral prolapse or when general anesthesia is contraindicated, because the results of medical treatment are less predictable than those of surgery. Certainly, when the urethral mucosa appears gangrenous or necrotic, conservative measures are not appropriate.
- Treatment of the other urethral anomalies discussed in this article is mostly operative.
- UTIs are managed with conventional treatment. For pyelonephritis, conventional treatment typically includes a second-generation cephalosporin (eg, cefotaxime) intravenously and antibiotics adjusted later, according to sensitivities.
Surgical Care
- Treatment of urethral duplications is individualized. In most instances, the ventral urethra is the functional one. Two thirds of patients require surgery. A decision as to which urethra to preserve (usually the ventral) must be made. Hypospadias and epispadias are treated with standard techniques (see Hypospadias, Exstrophy and Epispadias). Unknowing excision of the functional urethra may result in urinary retention or incontinence.
- Managing anterior urethral valves is a subject of controversy. While Rushton recommends cutaneous vesicostomy in the neonate, followed by endoscopic valve ablation when the child is older, others suggest 2-stage urethroplasty, the first stage to be performed in the neonatal period.
- Treatment of megalourethra follows the principles of surgery for hypospadias.
- Endoscopic resection is the treatment of choice for urethral polyps. Conversely, endoscopic marsupialization is used to correct urethral diverticula, sinus of Guérin anomalies, and Cowper duct cysts.
- Urethral prolapse is managed best with a modification of the Kelly-Burnam operation in which prolapsed mucosa is excised and the mucocutaneous junction is reapproximated with absorbable sutures. Ligation of the prolapsed mucosa over a Foley catheter is discouraged because of a higher complication rate (eg, infection, recurrence, prolonged need for analgesics).
- Perioperative antibiotics are used in all open and endoscopic procedures for the treatment of urethral anomalies and urethral prolapse.
Consultations
- Consult a pediatric urologist for children in whom urethral anomalies or urethral prolapse are suggested.
- Consult a pediatric nephrologist when associated obstructive uropathy is present (particularly in patients with anterior urethral valves).
Start treatment of pyelonephritis with a broad-spectrum IV antibiotic, which is modified according to sensitivities. Continue until the patient has been afebrile for 48 hours and the WBC count has normalized, at which time therapy can be switched safely to PO.
Drug Category: Antibiotic agents
These agents are used to treat pyelonephritis. Conventional treatment typically is initiated with a second-generation cephalosporin (eg, cefotaxime) IV. Antibiotic regimens are adjusted later according to culture and sensitivities.
| Drug Name | Cefotaxime (Claforan) |
| Description | Third-generation cephalosporin with gram-negative spectrum. Lower efficacy against gram-positive organisms. Arrests bacterial cell wall synthesis, which in turn inhibits bacterial growth. |
| Adult Dose | 1-2 g IV/IM q6-8h |
| Pediatric Dose | <1 week: 50 mg/kg/dose IV q12h 1-4 weeks: 50 mg/kg/dose IV q8h Children <50 kg: 50-180 mg/kg/d IV/IM divided q4-6h |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid may increase cefotaxime levels; coadministration with furosemide and aminoglycosides may increase nephrotoxicity |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Adjust dose in severe renal impairment; has been associated with severe colitis |
| Drug Name | Ampicillin (Marcillin, Omnipen, Polycillin, Principen, Totacillin) |
| Description | Usually used in combination with an aminoglycoside. Increased resistance to Escherichia coli is beginning to emerge. Exerts bactericidal activity against susceptible organisms. |
| Adult Dose | 500 mg to 3 g IV q4-6h; not to exceed 12 g/d |
| Pediatric Dose | 100-400 mg/kg/d IV/IM divided q4-6h |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives |
| Pregnancy | B - Usually safe but benefits must outweigh the risks.
|
| Precautions | Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction |
| Drug Name | Gentamicin (Garamycin, Gentacidin) |
| Description | Aminoglycoside antibiotic for gram-negative coverage. Used in combination with both an agent against gram-positive organisms and one that covers anaerobes. |
| Adult Dose | Loading dose and maintenance dose: 1-2.5 mg/kg IV and 1-1.5 mg/kg IV, respectively, q8h Extended dosing regimen for life-threatening infections: 5 mg/kg/d IV/IM q6-8h Follow each regimen by at least a trough level drawn 30 min prior to the third or fourth dose; may draw a peak level 0.5 h after 30-min infusion |
| Pediatric Dose | <5 years: 2.5 mg/kg/dose IV/IM q8h >5 years: 1.5-2.5 mg/kg/dose IV/IM q8h or 6-7.5 mg/kg/d divided q8h; not to exceed 300 mg/d; monitor as in adults |
| Contraindications | Documented hypersensitivity; non–dialysis-dependent renal insufficiency |
| Interactions | Coadministration with other aminoglycosides, cephalosporins, penicillins, and amphotericin B may increase nephrotoxicity; aminoglycosides enhance effects of neuromuscular blocking agents; thus, prolonged respiratory depression may occur Coadministration with loop diuretics may increase auditory toxicity of aminoglycosides; possible irreversible hearing loss of varying degrees may occur (monitor regularly) |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Narrow therapeutic index (not intended for long-term therapy); caution in renal failure (not on dialysis), myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; adjust dose in renal impairment |
Further Outpatient Care
- After any operation, schedule a follow-up visit to evaluate surgical outcome.
- In patients without obstructive uropathy, progress can be monitored by focusing on the symptomatology and, perhaps, with surveillance of the urine.
- When significant obstruction is present, follow-up care should include serial renal ultrasounds and at least one VCUG or RUG to document anatomic relief of the obstruction.
Complications
- In general, treatments are safe and effective and complications are infrequent. The following can complicate the operative repair of urethral anomalies and urethral prolapse:
- Bleeding
- Infection
- Urinary retention
- Incontinence
Prognosis
- Associated anomalies determine the prognosis of patients with fusiform megalourethra.
- While obstructive lesions may be managed successfully with various operative techniques, prognosis ultimately depends on renal damage secondary to obstruction and infection.
Medical/Legal Pitfalls
- Sexual abuse is common. Evidence indicates that physicians often are unable to recognize abnormalities in prepubertal female genital anatomy. This, in addition to a lack of familiarity with conditions such as urethral prolapse, can lead to a mistaken diagnosis of sexual abuse and serious consequences to the child and family.
- The literature reports at least one child with urethral prolapse who was temporarily separated from her family due to a mistaken diagnosis of sexual abuse.
- Anveden-Hertzberg et al found misdiagnosis or failure to diagnose in 79% of cases in a series of 24 patients with urethral prolapse.
- Urethral prolapse is the only condition in which a circumferential mass around the urethra can be found. This fact cannot be emphasized enough.
- AAP. Practice parameter: the diagnosis, treatment, and evaluation of the initial urinary tract infection in febrile infants and young children. Committee on Quality Improvement. Subcommittee on Urinary Tract Infection. Pediatrics. Apr 1999;103(4 Pt 1):843-52. [Medline].
- Anveden-Hertzberg L, Gauderer MW, Elder JS. Urethral prolapse: an often misdiagnosed cause of urogenital bleeding in girls. Pediatr Emerg Care. Aug 1995;11(4):212-4. [Medline].
- Bartone FF. The urethra. In: O'Donnell B, Koff S, eds. Pediatric Urology. 3rd ed. Butterworth-Heinemann;1994:526-536.
- Casale AJ. Posterior urethral valves and other obstructions of the urethra. In: Gonzales ET, Bauer SB, eds. Pediatric Urology Practice. 1st ed. Lippincott Williams & Wilkins;1999:240-244.
- Fernandes ET, Dekermacher S, Sabadin MA, Vaz F. Urethral prolapse in children. Urology. Mar 1993;41(3):240-2. [Medline].
- Goldman M, Lahat E, Strauss S, et al. Imaging after urinary tract infection in male neonates. Pediatrics. Jun 2000;105(6):1232-5. [Medline].
- Jerkins GR, Verheeck K, Noe HN. Treatment of girls with urethral prolapse. J Urol. Oct 1984;132(4):732-3. [Medline].
- Johnson CF. Prolapse of the urethra: confusion of clinical and anatomic characteristics with sexual abuse. Pediatrics. May 1991;87(5):722-5. [Medline].
- Lowe FC, Hill GS, Jeffs RD, Brendler CB. Urethral prolapse in children: insights into etiology and management. J Urol. Jan 1986;135(1):100-3. [Medline].
- Rudin JE, Geldt VG, Alecseev EB. Prolapse of urethral mucosa in white female children: experience with 58 cases. J Pediatr Surg. Mar 1997;32(3):423-5. [Medline].
- Rushton HG, Parrott TS, Woodard JR, Walther M. The role of vesicostomy in the management of anterior urethral valves in neonates and infants. J Urol. Jul 1987;138(1):107-9. [Medline].
- Schoellnast H, Lindbichler F, Riccabona M. Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography. J Ultrasound Med. Jun 2004;23(6):769-76. [Medline].
- Shurtleff BT, Barone JG. Urethral prolapse: four quadrant excisional technique. J Pediatr Adolesc Gynecol. Aug 2002;15(4):209-11. [Medline].
- Smith GH, Duckett JW. Urethral lesions in infants and children. In: Gillenwater JY, Grayhack JT, Howards SS, Duckett JW, eds. Adult and Pediatric Urology. 3rd ed. Mosby-Year Book;1996:2431-2443.
- Valerie E, Gilchrist BF, Frischer J, et al. Diagnosis and treatment of urethral prolapse in children. Urology. Dec 1999;54(6):1082-4. [Medline].
Urethral Anomalies and Urethral Prolapse excerpt Article Last Updated: Sep 15, 2006
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