Urethral Duplication in Children: Experience of Twenty Cases.

BACKGROUND AND
OBJECTIVE: Urethral duplication is a rare congenital anomaly having multiple anatomical variants and varied presentations. Multiple surgical techniques have been described for this anomaly, and no surgical technique is ideal. The aim of this study was to present our experience of twenty cases of urethral duplication in the management of this anomaly.
MATERIALS AND METHODS: Retrospectively over a period of 10 years from 2006 to 2016, records of all urethral duplications were reviewed. All available records were evaluated for clinical presentation, imaging studies (micturating cystourethrogram, retrograde urethrogram, ultrasonography, and cystourethroscopy), and classified according to the Effmann's classification. The intraoperative details, outcome, and follow-up (including cystoscopy and contrast studies) were noted.
RESULTS: There were 20 patients of urethral duplications. Age of patients ranged from 3 months to 9 years with a mean age of 4.6 years. The details of management, outcome, and follow-up were obtained.
CONCLUSION: Management varies with the symptoms and the severity of the anomaly. Y-type urethral duplication is more complex and challenging and requires extensive urethral reconstruction. Combined use of the bladder and buccal mucosa for reconstruction gives better results than bladder mucosa alone. Copyright:

INTRODUCTION

Urethral duplication is a rare congenital anomaly that was first described by Aristotle and Vesalius.[1] Since then, it has been reported as case reports or small case series and is mainly reported in young children and rarely in adulthood. Urethral duplication is more common in males with few case reports in females. The anatomic diversity and lack of a uniform embryologic theory have led to many classifications of urethral duplication. However, Effmann et al.[2] described a more complete classification of urethral duplication into three types and are currently mostly reported classification in the literature.

Presentation of urethral duplication differs according to the anatomical variant of duplication and can be asymptomatic as well. Management of urethral duplication depends on the presence of symptoms and type of anomaly and should be adapted to the individual patient. We present our experience of twenty cases of urethral duplication over 10 years to determine the appropriate management for this rare and complex anomaly. To the best of our knowledge, this is one of the largest series of urethral duplication reported in the literature.

MATERIALS AND METHODS

This retrospective study was conducted in the Department of Paediatric Surgery, Indira Gandhi Institute of Child Health, Bengaluru, India. Over a period of 10 years from 2006 to 2016, twenty cases of urethral duplication were managed. All available records were evaluated for clinical presentation, imaging studies, and classified according to the Effmann's classification [Table 1].

Table 1

Effmann’s classification of urethral duplication

Type	Description	Photographic representation
Type I	Duplicated urethra which opens on the penis
Type IIA1	Two independent urethras emerging from bladder and opening with two meatuses
Type IIA2	Second channel arising from the first independently courses into a second meatus
Type IIA2 (Y type)	Prostatic urethra splits into two channels with one extending to the glans and the more functional ventral one coursing to the perineum near the rectum
Type IIB	One meatus, two urethras arising from the bladder or posterior urethra unite in one channel
Type III	Urethral duplication as a component of partial or complete caudal duplication

Micturating cystourethrogram, retrograde urethrogram, ultrasonography, and cystourethroscopy data were retrospectively reviewed to delineate internal anatomy, type of urethral duplication, and associated anomaly. The intraoperative details, outcome, and follow-up assessment including cystoscopy and contrast studies were analyzed, results were tabulated, and conclusions were drawn.

RESULTS

There were 20 patients of urethral duplications. Age of patients ranged from 3 months to 9 years with the mean age of 4.6 years. Of twenty cases [Table 2], six patients were classified as Y-duplication [Figure 1], ten patients Type IIA2 [Figure 2a and b], two patients Type I [Figure 3], and one patient each Type IIB and Type IIA1. Type of urethral duplication, clinical presentation, management, outcome, and follow-up are shown in Table 3.

Table 2

Types of urethral duplication

Type	Frequency (%)
IIA2	10 (50.0)
Y	6 (30.0)
1	2 (10.0)
II B	1 (5.0)
IIA1	1 (5.0)
Total	20 (100.0)

Figure 1

(a and b) Y-urethral duplication

Figure 2

(a and b) Type IIA2 urethral duplication

Figure 3

Type I urethral duplication

Table 3

Type, presentation, management, and outcome of twenty cases of urethral duplication

Patients	Type	Presentation	Procedure done	Number of procedure	Associated anomaly	Outcome and follow-up
1	Y	Passage of urine from a ventral urethra situated near the dentate line	Staged BMTU	3	Nil	Had meatal stenosis, replaced with buccal mucosa, single good stream
1	Y	Passage of urine from a ventral urethra situated near the dentate line with dribbling from glans	Staged BMTU	2	VUR (left grade-2)	Had meatal stenosis, replaced with buccal mucosa, single good stream. Meatus at corona
1	Y	Passage of urine from a ventral urethra situated near the dentate line	Perineal urethrostomy with buccal mucosa tube urethroplasty	2	Nil	Recalcitrant stricture, not responding to dilatations, underwent Mitrofanoff procedure
1	Y	Passage of urine from a ventral urethra situated near the dentate line	Distal buccal and proximal bladder mucosal tube urethroplasty	3	Bilateral VUR (left grade-4 and right grade-2)	Penoscrotal fistula. Passing single good stream after fistula repair
1	Y	Passage of urine from the dorsal urethra with dribbling from the ventral urethra situated near the dentate line	Distal buccal and proximal bladder mucosal tube urethroplasty	2	Nil	Single good stream
1	Y	Passage of urine from the opening near the dentate line with dribbling from the meatus at the glans	Distal buccal and proximal bladder mucosal tube urethroplasty	2	Nil	Single good stream
1	I	Discharging sinus in prepubic area	Excision of accessory urethra	1	Nil	Single good stream
1	I	Penoscrotal abscess with fistula	Penoscrotal fistula excision	1	Left solitary kidney	Single good stream
1	II A1	Two urinary streams	Closure of opening of dorsal urethra within the bladder	1	Nil	Single good stream
1	II B	Straining with single stream	Urethrourethrostomy	3	Nil	Developed anastomotic stricture. Passing single good stream after urethral dilations[2]
1	II A2 with meatal stenosis	Thin stream with meatal stenosis	Meatoplasty	1	Nil	Single good stream
1	II A2	Straining while passing urine	PADUA technique	1	Nil	Single good stream
1	II A2	Dribbling from duplicated glans (Diphallus)	Excision of stenosed segment (2 cm) of the ventral urethra and ventral hypoplastic glans and Byar’s staged urethroplasty of proximal good caliber ventral urethra was done while retaining dorsal glans	2	Left solitary kidney with polydactyly	Single good stream
1	II A2	Straining during micturition and SPC was done in some another hospital	Perineal urethrostomy with buccal mucosa tube urethroplasty	3	Nil	Waiting for end-to-end anastomosis of perineal urethrostomy
1	II A2	Straining while passing urine. Single glans with two meati in the sagittal plane	VIU of ventral urethra done followed by repeated dilatations[3]	4	Nil	Single good stream
1	II A2 with EC	EC	Excision of duplicated urethral plate and end-to-end anastomosis of the ventral urethra with bladder closure	1	Nil	Occasional stress incontinence but passing single good stream
1	II A2	Two urinary streams	Awaiting	-	Nil	-
3	II A2	Asymptomatic	No procedure		Nil	-

BMTU: Bladder mucosa tube urethroplasty, PADUA: Progressive augmentation by dilating the urethra anterior, EC: Exstrophy complex, SPC: Suprapubic cystostomy, VIU: Visualized internal urethrotomy, VUR: Vesicoureteral reflux

Associated anomaly was present in 4 (20%) patients [Table 3].

Among six patients of Y-duplication, two patients underwent bladder mucosa tube urethroplasty (BMTU). Both the patients develop stricture at the distal meatus which required replacement with buccal mucosa. One patient underwent perineal urethrostomy with buccal mucosa tube urethroplasty. This patient develops multiple strictures not responding to dilatations and underwent Mitrofanoff procedure because parents did not agree for further urethral reconstructive procedures. Three patients underwent distal buccal and proximal bladder mucosal tube urethroplasty. All the three patients have single good urinary stream.

Surgical procedures and results of Type IIA2, Type I, Type IIB, and Type IIA1 are shown in Table 3. One patient with Type IIA2 is awaiting the surgical procedure. Three patients with Type IIA2 were asymptomatic, and no surgical intervention was done in these patients.

DISCUSSION

Urethral duplication is a rare congenital anomaly with roughly 300 cases reported in the literature till 2009.[3] This anomaly is found mostly in males with few cases reported in females. The embryology of urethral duplication is not well established, with possible explanations including ischemia, abnormal mullerian duct termination, failure of mesodermal fusion, and division of the notochord with subsequent formation of hindguts, allantois, and cloacae.[2456]

Urethral duplication most commonly occurs in the sagittal plane with one urethra located ventrally and the other dorsally and is divided into either dorsal or ventral duplication. Some rare duplication occurs in the same horizontal plane (collateral urethral duplication) in which urethras lie collaterally (side by side).

These anomalies may be complete or incomplete.[7] Incomplete urethral duplications are more common than complete urethral duplications.[8] A complete duplicated urethra emerges from the urinary bladder and opens somewhere on the penis or on the perineum. An incomplete duplicated urethra may not originate from the bladder and may not have an external opening.

There are three anatomic variants of urethral duplication: epispadiac (dorsal), hypospadiac (ventral), and Y-type.[9] However, according to the Effmann's classification,[2] there are three types. Type I is a blind incomplete urethral duplication. Type IA is represented by a duplicated urethra which opens on the penis and does not communicate with the urethra. In Type IB, the duplicated urethra opens like an extension from the urethra and ends blindly in the periurethral tissue (this is a rare type). In Type II, there is complete urethral duplication. In Type IIA1, there are two independent urethras emerging from bladder and opening with two meatuses. Type IIA2 is represented by a single proximal channel opening in double streams, and Type IIB is represented by two urethra opening in a single meatus. In Type III, urethral duplication is a component of caudal duplication.

The common clinical presentation of urethral duplication is a double meatus and double urinary stream. Other presentations can be straining, incontinence, urinary tract infection, penile chordee, and urinary obstruction secondary to a mucosal flap at the urethral bifurcation acting as occluding valve during voiding.

The incidence of Y-duplication in our series is 31.8%. Other authors have reported 6% to 30%.[1011] Associated anomalies have been described in the genitourinary, gastrointestinal, and musculoskeletal system. Most of the series have reported associated anomalies in 60% to 80%.[3] In our patients, associated anomalies were seen in 20.0% of patients. Mane et al.[3] reported associated anomalies in 25% of cases in his series.

Management of the urethral duplication varies with the symptoms, anatomy, and the severity of the anomaly. Individually tailored treatment is advised by most authors, and there is a consensus on treating only symptomatic patients.[11213] In our patients also, we treated only symptomatic patients. In symptomatic patients, no standard surgical techniques have been described for urethral duplication; many authors have reported various techniques in their studies. Surgical procedure is individualized depending on the type of malformation. Gozar et al.[14] reported two and Luciano et al.[15] reported three cases of Type I of urethral duplication. The authors excised the duplicated (accessory) urethra with good functional and cosmetic outcome. In our series, we did excision of accessory urethra (Type I) in one patient with good outcome.

Mane et al.[3] in their series reported two cases of Type IIB, one was managed with excision of accessory urethra and other one by dilatation of urethra. Authors reported the good outcome with single good urinary stream in both the patients. We did urethrourethrostomy with tubularized incised plate repair in one patient with Type IIB anomaly. He had anastomosis stricture; after dilatation, he is now passing single good urinary stream.

Surgical repair of the Y-type urethral duplication is more complex and challenging and requires extensive urethroplasties with tissue transfer such as buccal or bladder mucosa grafts. The Y-duplication occurs when the prostatic urethra splits into two channels with one extending to the glans and the more functional ventral one coursing to the perineum near the rectum. In the management of urethral duplication, the first step is to identify the normal-functioning urethra (the urethra with the largest caliber, a normal verumontanum, and an intact sphincter). This variety of urethral duplication requires mobilization of the ectopic ventral channel from the perianal region and later on distal urethroplasty in the second stage or completing the reconstruction in a single stage. Various types of tissue can be used for the urethral reconstruction such as the bladder mucosa, buccal mucosa, preputial island flaps, and scrotal flaps. Williams and Bloomberg[16] had used scrotal flaps for Y-type urethral duplication. However, results with scrotal flaps for hypospadias have been disappointing because of the possibility of creating a hairy urethra. Foreskin, bladder mucosa, and buccal mucosa are reasonably good option for urethroplasty. Mane et al.[3] have used buccal mucosal graft in two cases and combined bladder and buccal mucosal graft in one case with good outcomes. We used bladder mucosa in two patients; both had stricture at distal meatus which required replacement with buccal mucosa. Combined bladder and buccal mucosal graft was used in three patients. Proximally bladder mucosa and distally buccal mucosa were used. All the three patients have good cosmetic and functional results. Buccal mucosal tube in distal part of reconstruction was used to prevent stenosis/stricture of exposed bladder mucosa. We learned this from the complications we faced with complete bladder mucosal tube repair in two patients. Tunneling the tube through the scrotum and penile dartos fascia without opening it has the advantage of achieving good cosmesis. We did it in four patients with good functional and cosmetic outcome [Figure 4a and b].

Figure 4

(a) Bladder mucosa urethral tube. (b) Tunneling of the tube through the scrotum and penile dartos fascia

CONCLUSION

Urethral duplication is an uncommon anomaly with variable clinical presentation. Surgical management varies with the symptoms and the severity of the anomaly. Asymptomatic patients do not require any surgical treatment. Simple accessory duplicate urethra can be excised provided the native urethra is of normal caliber.

Y-type urethral duplication is more complex and challenging and requires extensive urethral reconstruction. Combined use of bladder and buccal mucosa for reconstruction gives better results than bladder mucosa alone.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.