What is a Urinary Fistula?
A urinary fistula is an opening in the urethra that causes urine leakage. It most commonly occurs at the junction of the native and neourethra, although a fistula can occur anywhere along the neourethra. A fistula that heals with excessive scarring may eventually lead to stricture formation.
Precise estimates of the risk of fistula are difficult to ascertain, but they can differ by procedure:1
- Suprapubic abdominal flaps have a high fistula rate of 55%.
- RFFF phalloplasty has reported fistula rates ranging from 22 to 68%.
- Prelaminated Osteocutaneous Fibula Flap Phalloplasty has fistula rates ranging from 15 to 22%.
- Surprisingly, the pedicled flaps namely the ALTF and the extended pedicle groin flap have the lowest reported fistula rates of <10%.
What Causes a Fistula?
- Inadequate blood supply to the urethra
- Too much moisture causing junction of native and neourethra to not heal well
- Urethral catheters left in too long2
Most urethral fistulas can be managed using non-surgical options and/or urinary diversion with a catheter. Fang et al reported spontaneous closure of the fistula within 2 months in as many as 35.7% of patients.3 Up to 15% of patients required revision surgery in the study with the longest follow-up duration, to date.4
For fistula repair surgery, Reconstructive Urologist Dr. Dmitriy Nikolavsky uses a fasciocutaneous groin flap or a labial fat pad flap harvested from the neoscrotum.5
New Techniques to Minimize Fistula
New FTM Phalloplasty and Urethroplasty techniques are being developed to minimize the risk of fistula. For example, Dr. Salgado has developed a technique that integrates a pedicled gracilis flap into the urethral construction. In his study, the four patients who underwent the immediate myofascial gracilis flap procedure had no evidence of urethral fistula at up to 12 months follow-up duration.6
Footnotes1. Rashid M, Tamimy MS. Phalloplasty: The dream and the reality. Indian J Plast Surg [serial online] 2013 [cited 2017 Aug 2];46:283-93. http://www.ijps.org/text.asp?2013/46/2/283/118606
2. David J. Ralph. "Urethral Complications in Phalloplasty", http://library.transgenderzone.com/?page_id=1680.
3. Fang, R.-H., Lin, J.-T. and Ma, S. (1994), Phalloplasty for female transsexuals with sensate free forearm flap. Microsurgery, 15: 349–352. doi:10.1002/micr.1920150512, http://onlinelibrary.wiley.com/doi/10.1002/micr.1920150512/abstract
4. Morrison, Shane D., Chen, Mang L., Crane, Curtis N. An overview of female-to-male gender-confirming surgery, Nature Reviews Urology, 14, 486–500 (2017). http://www.nature.com/nrurol/journal/v14/n8/full/nrurol.2017.64.html
5. Dmitriy Nikolavsky et al, "Management of Unfavorable Urologic Sequelae After Phalloplasty in Transgender Patients," in Gender Affirmation: Medical and Surgical Perspectives (Thieme, Dec 1, 2016.)
6. Salgado CJ, Nugent A2, Moody AM, Chim H, Paz AM, Chen HC. Immediate pedicled gracilis flap in radial forearm flap phalloplasty for transgender male patients to reduce urinary fistula. J Plast Reconstr Aesthet Surg. 2016 Nov;69(11):1551-1557. doi: 10.1016/j.bjps.2016.05.011. Epub 2016 Jun 2. https://www.ncbi.nlm.nih.gov/pubmed/27372000