Y-Type Urethral Duplication Presented with Perianal Fistula in an Infant İnfantta Perianal

Urethral duplications are rare lower urinary tract anomalies. Here we present an unusual presentation of urethral duplication in which, completely patent accessory urethra was coursing laterally on perianal region, near the anus, and presented as perianal fistula. A 2-month-old boy presented with discharge from the perianal region. On physical examination a fistula was observed on perianal region, in the 1 o’clock position and only 1 cm near the anus. Fistulography showed an opening to the prostatic urethra. The opening to the urethra was seen left superior part of the verumontanum on cystourethroscopy by giving methylene blue from the fistula. The accessory urethra was dissected from the skin to the prostatic part of the orthotopic urethra and excised completely with anterior sagittal approach. His postoperative course was uneventful. In unusual form of urethral duplications of Effmann Type IIA2, as in our case, orthotopic urethra is normal and ventral urethra opens to the perineum. It should be kept in mind that especially laterally placed ones can be misdiagnosed as anal fistula.


INTRODUCTION
Duplication of urethra is a rare lower urinary tract anomaly and is more common in males (1,2).Multiple anatomical variants were described with different clinical manifestations (3).We report here an unusual presentation of urethral duplication in which, completely patent accessory urethra was coursing laterally on perineal region, near the anus, and presenting as an anal fistula.

CASE REPORT
A 2-month-old boy presented with discharge from the perianal region.There was no story of perianal abscess, no instrumentations and no other traumas in his past medical history.On physical examination, a fistula was observed on perianal region, at the 1 o'clock position and only 1 cm near the anus.Other physical findings and abdominal ultrasonography were normal.Informed consent was obtained from the patient's relatives prior to the procedure.

Case Report / Olgu Sunumu
The fistulography with water-soluble contrast showed that the fistula tract was coursing anteriorly from the perineum to the posterior prostatic urethra (Figure 1).He was diagnosed as urethral duplication and cystourethroscopy was made first to evaluate the orthotopic urethra.
The orthotopic urethra, the verumontanum and the bladder were normal.During cystourethroscopy methylene blue was injected into the fistula on the perianal region and the flow was seen in the left part of prostatic urethra just near the verumontanum (Figure 2).The therapeutic decision was excision of the posterior ventral tract communicating between the urethra and the perineum.A ureteral stent was inserted into the meatus of accessory urethra on the perineum (Figure 3).Anterior sagittal incision was made between the anus and scrotum.The accessory urethra was the skin to the prostatic part of the orthotopic urethra and was excised totally (Figure 4).His postoperative course was uneventful.Urethral duplication 59 DISCUSSION duplications may be sagittal or coronal.Most of them occur in the sagittal plane with two channels running one above the other in the sagittal plane.Effman et al, classified urethral duplications into three types and elaborated them.In type I, there is partial duplication of the urethra.Type II is the complete duplication of urethra and can be classified in two subtypes.There are two meatus in Type IIA.In Type IIB there is two urethral channels arise from bladder or posterior urethra and they unite at the distal part and has one meatus.Type III urethral duplication comprises complete duplication of the urethra and bladder (1).
Y-Type duplication is a special form of Type IIA2 urethral duplications.In type of duplication both two urethras originate from a common bladder neck or posterior urethra and the ventral accessory urethra opens onto perineum independently.Possible mechanism of embryologic development of Y-Type duplication is the fistula formation in the dorsal margin of urogenital sinus due to possible vascular accident.On the other side impaired growth of the dorsoinferior wall of urogenital sinus and faulty closure of the urorectal membrane are the other suspicious mechanisms for the development of Y-Type duplication (4,5).
Patients may present with different clinical manifestations and on different ages.Clinical symptoms may be very variable such as double urinary stream, urinary incontinence, recurrent urinary tract infections, epididymitis, perineal abscess and outflow obstructions.Diagnosis of Y-Type urethral duplication is made with voiding cystourethrography, retrograde urethrography and fistulography.Cystourethroscopy should be performed to confirm the radiographic findings.It is important to determine which urethra is the more functioning one, especially in Y-Type duplications.The normal urethra has larger calibration, a well developed sphincter mechanism and a normal verumontanum (6,7).
There are two variants of Y-Type duplications: (i)Stenotic orthotopic: Orthotopic dorsal urethra is stenotic, more functional accessory ventral urethra opens into the perineum or anal channel.
(ii)Unusual form: There is hypoplastic ventral urethra and dorsal urethra is the normal channel.Because in all duplications except this very rare form, the ventral urethra is the more functioning urethra (1,6,7).
The excision of accessory perineal urethra is the surgical treatment of unusual forms, and it is enough alone.Y-Type duplications with stenotic orthotopic urethra, due to the perineal urethra has got verumontanum and sphincter mechanisms, and require more complex surgical interventions (2,4,5,6,7).

CONCLUSION
It should be kept in mind, especially the duplications that open laterally, outside the midline, such as in our case may be misdiagnosed as an anal fistula.Cystourethroscopy should be performed to confirm the radiographic findings and to determine the functioning urethra, especially for Y-Type urethral duplications, then the surgical management should be planned.

Figure 1 .
Figure 1.Contrast material outlining the accessory urethral tract from the left perianal region to the prostatic urethra.

Figure 2 .
Figure 2. Communication of the duplicated urethra with the prostatic urethra is demonstrated by injection of contrast material through the perianal orifice during the cysto-urethroscopy procedure (cystourethroscope is in the native urethra).

Figure 3 .
Figure 3.The accessory urethral tract is dissected by the aid of traction sutures and a stent inserted in the duplicated accessory urethra while a Foley catheter is in the native urethra.

Figure 4 .
Figure 4. Dissection of the accessory urethra through a midline perineal incision is in progress.