Urethroperineal fistula in a patient with a stone in a bulbar diverticulum after a scrotal skin flap urethroplasty: A case report.

Introduction

The urethra is vulnerable to trauma, disease, or congenital defects and management options are often narrow. Urethral reconstruction has been done for years, and advances in techniques and procedures are ongoing. One of the oldest procedures is ventral scrotal skin flap urethroplasty, a procedure of which one of the most common complications is urethral diverticulum, thus the new trend of using a buccal mucosa urethroplasty. A urethral diverticulum is a localized pouch like dilatation extending from and adjoining to the urethra and is a rare clinical entity. Urethral diverticula in males are usually caused by trauma, infection, impacted stone or stricture disease. Rarely, it can develop as a complication of urological procedures. Urethral diverticulum with a urethral calculus causing a urethroperinial fistula is a rare and peculiar finding and has been reported only once before in English literature. We present a case of 62 years old male with a history of scrotal skin flap urethroplasty 30 years ago. The patient had a urethroperineal fistula extending from the ventral aspect of the penis towards the perineum associated with a diverticulum of the bulbar urethra with a taut of hair being a nidus for stone formation. To the best of our knowledge only one case in English literature has been published.

Case report

We present a 62 years old male who is a known case of Diabetes Miletus, Hypertension, and Dyslipidemia who was presented to our Urology clinic complaining of long standing lower urinary tract symptoms (dysuria, weak stream, and intermittency) for 10 years associated with purulent urethral discharge. He had a history of a urethral stricture 35 years ago, for which he underwent Urethroplasty with a scrotal skin flap. Upon examination, a mass was felt at the midline of perineum behind the scrotum (Fig. 1), the mass appeared inflamed, hard, non-mobile, with a punctum and purulent discharge. Clinically the patient was stable with normal laboratory values, MRI of the pelvis showed a urethroperineal fistula extending from the ventral aspect of the penis towards the perineum with no internal anorectal opening. Urethrogram was done which showed a diverticulum of the posterior urethra, with a filling defect representing a possible stone with no contrast leak through the perineum (Fig. 2). On cystoscopy, there was a bulbar urethral diverticulum with hair growing in and a stone just distal to the external urethral sphincter. The bladder was trabeculated so a suprapubic catheter was inserted under direct vision to divert the urine. Intra-operatively, through a perineal elliptical incision around the fistula dissection was done till the urethral diverticulum was reached and opened, The diverticulum was 4 cm in length and 5 cm in width, a stone was seen inside the diverticulum along with the hair growing in from the scrotal skin flap (Fig. 3). Excision of the urethral diverticulum and scrotal skin flap was done keeping a urethral plate of 3 cm which allowed for primary closure with absorbable sutures. The patient then was discharged with Foley's catheter as well as a suprapubic catheter. Cystourethrogram was done 3 weeks after discharge, which showed normal contrast passage with no leak or stricture. Patient was kept off Foley's catheter and Uroflowmetery was done showing urine peak flow rate of 20 ml/s and a post void residual of 30 ml. Suprapubic catheter was removed then and patient was voiding freely.

Fig. 1

The mass is observed at the midline of perineum.

Fig. 2

Retrograde urethrogram showing a bulbar diverticulum with a filling defect representing a stone.

Fig. 3

The stone wrapped with hair inside the diverticulum.

Discussion

Major complications of scrotal flap urethroplasty include stricture recurrence, post void dripping and the formation of a diverticulum along the urethra. The presence of urethral stones is a rare finding, 0.3% of all stones in the genitourinary tract, and is usually preceded by urethral stricture and diverticulum formation. The most common site for urethral stones to form is the posterior urethra. Patients who undergo urethroplasty with untreated scrotal skin flap carry the risk of having a hair bearing urethra. They are at increased risk of obstructing their urethra by the hair growth over the scrotal flap, and with time a diverticulum develops and a stone may be present or form, this may be a potential source of infection. Urethral stones and diverticulae are often present together and accompanied by lower urinary tract symptoms. Hair growth over the scrotal skin flap suggests the possibility of primary stone formation and the subsequent development of the diverticulum. One of the most important risk factors in primary stone formation in a male urethral diverticulum is urethral surgeries, especially with scrotal skin flap used in urethroplasty as in our case, urethral hair growth, stone and diverticulum formation might be a severe complication for such a surgery. Urethral calculi that cause urethropreineal fistula are extremely rare. We believe that this rare finding is under reported in the literature and needs more attention by Urologists.