Vol. 117, April Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
DUPLICATION OF THE MALE URETHRA SAKTI DAS
STANLEY A. BROSMAN
From the Department of Surgery/Urology, Harbor General Hospital, Torrance, California
Our experience with 4 male subjects with accessory urethras is reported. The anatomic types, clinical presentations and treatment modalities of urethral duplication are discussed. Our scrutiny of all cases reviewed in the literature led us to classify patients into 3 types, depending upon the anatomic and embryologic features. Type 1 is a complete accessory urethra arising from a separate or confluent opening within the bladder and extending to an external orifice. Type 2 includes accessory urethras that arise from the primary urethra and may or may not extend to a distal orifice. Type 3 is the most unusual anomaly, in which 1 of the duplicated urethras arises from the bladder or proximal urethra and opens onto the perineum. Urethral duplication is an unusual congenital anomaly initially described by Aristotle. I The anomalous urethra occurs primarily in men and may be complete or partial. Each form of duplication has a distinctive anatomic appearance and specific symptom complex. Many accessory urethras are disregarded by the patient because there is an insignificant abnormality and a lack of obvious urinary dysfunction. Our experience with the diagnosis and treatment of 4 patients prompted this review.
lower urinary tract infection associated with dysuria and postvoid dribbling. An excretory urogram was normal and a urethrogram outlined an incomplete duplication of the urethra communicating with the floor of the bulbar urethra and extending distally for 3 cm. (fig. 2). Endoscopic examination revealed the opening of the accessory urethra and effiux of fluid from the bladder was noted to elevate a mucosal flap permitting filling of the accessory tract. Transurethral division of the interurethral mucosal septum was performed by passing an electrode fashioned with a wire stylet through a No. 3 ureteral catheter. The accessory channel, thus, was marsupialized into the main urethra. The patient has been free of urinary tract infections for several years postoperatively. Case 3. T. L., a 29-year-old man, had been treated for bacterial prostatitis. Previous investigation had disclosed the presence of a urethral duplication. Urethrography disclosed an incomplete non-communicating accessory urethra opening onto the glans. The patient had no urologic symptomatology and no therapy for the accessory urethra was advised. Case 4. E. H., a 53-year-old man, had a life history of voiding through 2 orifices. The patient presented in urinary retention because of an inflamed bulbous urethral stricture. A ventral orifice on the glans communicated with the penile urethra for 6 cm. Because the accessory urethra produced no clinical problems therapy was restricted to management of the urethral stricture.
Case 1. G. L., a 42-year-old man, had a history of recurrent attacks of gonorrhea. The patient complained of purulent discharge from an opening on the glans penis dorsal to the normally placed urethra. There was no history of urethritis or passage of urine from the dorsal meatus. A dorsal curvature of the penis was present on erection but did not affect sexual performance. The patient voided and ejaculated only through the normally situated external meatus. On examination the only abnormality was an accessory opening on the glans penis 1 cm. dorsal to the normal external meatus. Retrograde urethrography demonstrated a normal ventral urethra with a parallel dorsal accessory urethra ending blindly approximately 1 cm. superior to the prostatic urethra (fig. 1). A 2 cm. accessory channel arising from the floor of the proximal bulbar urethra also was demonstrated. The dorsal channel was examined with a 12F pediatric panendoscope and revealed only areas of congestion in a tapering blindending tube. Endoscopy of the ventral urethra showed neither obstruction nor communication with the dorsal urethra. The orifice of the ventral accessory channel could be identified in the bulbous urethra. Because of the recurrent episodes of refractory gonococcal urethritis involving the blind accessory dorsal urethra surgical excision was performed. A transverse sleeve incision was made over the dorsal half of the penile circumference and skin flaps were dissected proximally to the symphysis pubis and distally to the balanopreputial groove. The accessory urethra was dissected from its bed beneath Buck's fascia and between the 2 corpora cavernosa. The distal end was totally excised with a small segment of the glans. Proximally, the tract was dissected beneath the symphysis to the urogenital diaphragm, clamped and divided. The wound was closed and a small suction drain was left in place for 48 hours. Convalescence was uneventful. Case 2. B. W., a 12-year-old boy, had several episodes of Accepted for publication June 25, 1976. Read at annual meeting of Western Section, American Urological Association, Coronado, California, February 22-26, 1976.
Urethral duplication is a relatively rare anomaly, having been reported in approximately 136 patients. I-20 In 1950 Gross and Moore presented the most comprehensive report, consisting of 83 patients culled from the literature and included 2 of their own. I Since the review by Gross and Moore 53 patients have been reported, including 4 of our own. We have not included in this review the reports of double urethras associated with more complex anomalies, such as diphallus, vesical duplex and colonic duplication. The anatomical variations have been classified and modified by various authors since the early descriptions of this anomaly. Gross and Moore defined a complete duplication as a second passage from the bladder to the meatus, through the dorsal surface of the penis or vulva. However, at some point, particularly at the beginning or termination of the urethra, this passage may become atretic or obliterated. Therefore, an embryologically complete duplication may not be anatomically patent at the time of presentation. After a review of the literature we noted that the patients could be divided into 3 groups based upon anatomic features (fig. 3).
In type 3 a rare pattern is observed. In 7 of our ;,o.citau,c:, a complete accessory urethra arose from a opening in the bladder neck or from a dilated prostatic urethra and ended in the perineum, anterior to the anal verge. The main urethra may be normal or atretic. EMBRYOLOGY
FIG. 1. Case 1. Simultaneous injecting urethrogrnm shows long dorsal accessory urethra and short ventral duplication.
Because of the anatomic variants the same embryologic mechanism may not explain each type of duplication. The embryologic theories offered to explain this anomaly include: 1) progressive mesenchymal constriction of abnormally placed urethral tissue, which can lead to a complete or partial separation of these epithelial structures resulting in a complete or incomplete accessory urethra, 2) abnormal forward continuation of the urorectal septum causing bifurcation of the urethral anlage, 3) bifurcation of the urethral gutter or crest and 4) delayed fusion of the paired buds of the genital tubercle. Our explanation is based on the theory that embryologic anomalies can arise from a disparity in the growth of various components of an organ system secondary to defective or disproportionate formative stimuli. Type 1, or complete urethral duplication, could arise as a result of uncoordinated growth between the phallic segment of the urogenital sinus and the maturation of the urethral crest epithelium. A delay in the development of the urethral crest may occur while the pars phallica of the urogenital sinus, or part ofit, continues to grow distally into the genital tubercle or the phallus. The urethral segrnent of the urogenital sinus grows towards the dorsally located genital tubercle and any ventral migration also is prevented the barrier provided the mesenchyma of the urorectal septum. This may ~,,,-u-uu the accessory urethra in a complete duplication always is located dorsally. However, at a later stage the urethral crest cells mature, proliferate and establish a new and more definitive communication with the ostium of the urogenital sinus. According to the hypothesis the ventral urethra appears chronologically and develops
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from a ;;,p1n'"""'t·p or confluent ~r,·····co tends to an external dorsal to main the accessory urethra was real urethra. The external may be located on the or the groove the glans, at the corona or at the base of the 2 the accessory urethra arises from the urethra and continues dorsal or with or an external opening. This also includes patients with accessory urethras with openings and variable lengths of urethra that terminate blindly. The patients in this group tend to be equally divided into a dorsal or ventral location of the accessory urethra. Forgaard and Ansell presented a patient in whom a urethral trifurcation existed with a dorsal as well as a ventral accessory urethra communicating separately with the main urethra. 2 One of our patients also had a small ventral tract from the bulbar urethra that could be interpreted as a third urethra. The differential diagnosis in these patients includes urethral diverticula, a dilated Cowper's duct, a disrupted retention cyst of Cowper's gland or a false passage of the urethra. ~~LU·J-O~LC,ULLL,.~
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FIG. 3. Types of duplication
DAS AND BROSMAN
later in fetal life. This concept may be supported by a number of instances in which the main urethra is hypospadiac. Type 2, or incomplete accessory urethras, may arise as a result of anomalous fusion of the genital folds causing bifur-cation or complete sequestration of a part of the urethral anlage. The type 3 patients, in whom the functional accessory urethra opens into the perineum, seem to have undergone a feminine differentiation anatomically and embryologically. The pars phallica of the urogenital sinus remains undifferentiated in the 25 mm. embryo. Further sexual differentiation of the urethra depends on the preponderance of the wolffian or mullerian duct activity. A transient non-suppression or overactivity of the mullerian system would result in the urogenital sinus opening more ventrally in the perineum. Later, as masculine differentiation from wolffian duct activity proceeds, the development of the phallus and the phallic portion of urethra is completed. Incomplete descent of the testes has been associated in this type of urethral deformity. CLINICAL FEATURES AND DIAGNOSIS
Symptoms, if present, can include urinary tract infection, a double stream, incontinence, outflow obstruction and dorsal chordee. The specific symptom complex depends upon the type of duplication. Patients with type 1 duplication commonly present with a double stream, which can be annoying, especially if one of the urethras opens proximally on the penis. Varying degrees of incontinence were noted in 12 of the 41 patients reviewed. This may be related to inadequate development of the proximal continence zone and sphincter mechanism of the accessory urethra. Dorsal chordee was seen more often in type 1 patients because of the dorsal location of the ill developed accessory urethra. Infection is the most common presenting feature in patients with type 2 blind-ending tracts. In 1 of our patients recurrent gonococcal infection was localized to the accessory urethra. This may be owing to stagnation and absence of a cleansing stream of urine. Urinary obstruction occurred in a few children with type 2 duplication.s-10 In our second patient the obstruction was caused by a mucosal flap at the urethral bifurcation acting as an occluding valve during voiding. Distension of a blind accessory urethra9 or an accessory urethra with a stenosed distal opening8 can cause obstruction by compression on the main urethra. In type 3 duplication the perinea! urethra appears to be more prominent anatomically and functionally. Patients are continent of urine. They void and ejaculate mostly through the perineal urethra and often suffer recurrent lower urinary tract infection. The principal diagnostic studies include retrograde and voiding cystourethrography and cystourethroscopy. The latter often is supplemented by dye instillation to determine a possible site of communication. Funfack succeeded in injecting air to observe a minute orifice in the bladder that did not show with contrast studies. 11 TREATMENT
Various treatment modalities have been used, depending upon the type of duplication and the clinical presentation. Complete duplication (type 1) may be excised by a combined retropubic and penile approach. Urethrourethrostomy has been performed successfully to eliminate annoying double
stream and is especially suitable when 1 of the urethras is epispadiac 12 or hypospadiac. 13 Electrodesiccation or injection of sclerosants can produce thrombosis of the corpora or chordee from fibrosis and are of unpredictable efficacy. Incomplete duplications (type 2) that give rise to recurrent infections can be excised. Bifid urethras with urinary tract obstruction can be managed with transurethral or open 10 excision of the thin interurethral septum. An open division and urethroplasty may be necessary for patients with more substantial interurethral tissue. Type 3 duplication presents the most formidable problem of reconstruction. Scott treated his patient by dissecting the perineal urethra and implanting it into the bulbar portion of the phallic urethra. 3 Chatelain and associates excised the perinea! urethra and reconstructed the narrow penile urethra. 7 Williams advocated a staged approach, in which the perineal urethra is first transplanted more anteriorly and subsequently advanced to the distal penis by a buried strip urethroplasty. 4 REFERENCES
1. Gross, R. E. and Moore, T. C.: Duplication of the urethra. Report of two cases and summary of literature. Arch. Surg., 60: 749, 1950. 2. Forgaard, D. M. and Ansell, J. S.: Trifurcation of the anterior urethra: a case report. J. Urol., 95: 785, 1966. 3. Scott, W. W.: Two unusual urethroplasties. Amer. Surg., 26: 196, 1960. 4. Williams, D. I.: Paediatric Urology. London: Butterworth & Co., p. 268, 1968. 5. Selvaggi, F. P. and Goodwin, W. E.: Incomplete duplication of the male urethra. Report of an unusual case. Brit. J. Urol., 44: 495, 1972. 6. Karanjavala, D. K.: An unusual case of complete reduplication of the urethra. Aust. New Zeal. J. Surg., 39: 284, 1970. 7. Chatelain, C., Boureau, M., Van Kote, G. and Weisgerber, G.: Bifidite urethrale a abouchement pre-anal. J. Urol. Nephrol., 79: 648, 1973. 8. Higgins, T. T., Williams, D. I. and Nash, D. F. E.: The Urology of Childhood. London: Butterworth & Co., 1951. 9. Liban, E.: Rare malformation of urethra as a cause of congenital obstruction of lower urinary tract. Amer. J. Dis. Child., 84: 340, 1952. 10. Fellows, G. J. and Johnston, J. H.: Incomplete urethral duplication and urinary retention. Brit. J. Urol., 46: 449, 1974. 11. Funfack, M.: Komplette doppelte Harnriihre beim Manne; ein weiterer Beitrag zur Kasuistik von Fehlbildungen der Harnorgane. Z. Urol., 46: 391, 1953. 12. Romeu, J. G.: Doble anomalia uretral. Rev. Cubana Ped., 33: 125, 1962. 13. Durrani, K. M., Shah, P. I. and Kakalia, G. R.: Interurethral fenestration for a case of double urethra with hypospadias. J. Urol., 108: 586, 1972. 14. Olsen, J. G.: Complete urethral duplication in a boy. J. Urol., 95: 718, 1966. 15. Casselman, J. and Williams, D. I.: Duplication of the urethra. Acta Urol. Belg., 34: 535, 1966. 16. Hermann, G. and Goldmann, H.: Double urethra with vertebral anomaly. Int. Surg., 58: 574, 1973. 17. Cullen, T. H.: Duplication of the male urethra. Brit. J. Surg., 60: 751, 1973. 18. Susan, L. P., Roth, R. B. and Kaminsky, A. F.: Complete duplication of urethra. Urology, 5: 390, 1975. 19. Redman, J. F. and Bissada, N. K.: Accessory urethra withjuxtaposed meatus. Urology, 5: 246, 1975. 20. Mehan, D. J. and Gonzales, J. H.: Urethral duplication. With associated agenesis of left kidney and right ureteral ectopia. Urology, 6: 476, 1975.