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
AND
STANLEY A. BROSMAN
From the Department of Surgery/Urology, Harbor General Hospital, Torrance, California
ABSTRACT
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 REPORTS
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.
DISCUSSION
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).
452
453
DUPLICATION
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
Duplication urntllro arises proximally from Ci ~ps:m:ite or co11fllll@nt opening in th® bia!l!di11' cmd
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
DUPLICATION OF THE MALE URETHRA SAKTI DAS
AND
STANLEY A. BROSMAN
From the Department of Surgery/Urology, Harbor General Hospital, Torrance, California
ABSTRACT
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 REPORTS
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.
DISCUSSION
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).
452
453
DUPLICATION
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
Duplication urntllro arises proximally from Ci ~ps:m:ite or co11fllll@nt opening in th® bia!l!di11' cmd
