Photoselective vaporisation of the prostate (PVP) therapy, also known as Greenlight laser, is an alternative treatment modality to transurethral resection of the prostate (TURP) for management of benign prostatic hypertrophy (BPH). A rare complication is the occurence of prostatosymphyseal fistula (PSF). There has been 14 reported cases in the literature to date. We describe a new technique of robotic prostatosymphyseal fistula repair by using the urachus as an interposition flap.

A 70-year-old male presented to our hospital with a history of lower urinary tract symptoms, 2 litre chronic urinary retention, large bladder diverticulae and prostatomegaly. He then underwent PVP and a follow-up robotic diverticulectomy procedure. After this second procedure, he developed perineal pain and difficulty mobilising on post-operative day 7. Urine culture demonstrated enterococcus faecalis. A pelvis MRI demonstrated osteomyelitis of the pubic symphysis and a fistula tract extended from the anterior prostate to the pubic symphysis. He failed conservative management with an indwelling urethral catheter and intravenous antibiotics.

We performed our procedure on the Da Vinci Robotic Xi platform. The operative steps are as follows. The bladder was mobilised off from the anterior abdominal wall and the Space of Retzius was developed. The prostate was separated from the pubic symphysis via endopelvic fascia dissection. This enabled the fistula tract to be identified. The pubic bone was then debrided. A Y-V plasty was performed at the bladder neck, therefore allowing the fistula tract to be closed over. The urachus was then mobilised into the pelvis. It was then sutured over the Y-V plasty reconstruction site. A leak test was performed which was negative. Our patient had an uncomplicated post operative recovery. They had a negative cystogram and passed a successful trial of void on post operative day 14. He had a prolonged course of oral antibiotics. Follow-up imaging involving CT and MRI imaging scans showed resolution of the fistula. At the 1-year follow-up he no longer had any perineal pain and denied having further lower urinary tract symptoms.

Prostatosymphyseal fistula is a very rare complication of PVP. The urachus is a very vascular structure and is readily accessible in the pelvis. It can serve as a valuable reconstruction option in fistula repair. In our patient, we have demonstrated successful implemention of the urachus interposition flap technique in robotic assisted prostatosymphyseal fistula repair.