The most common and frustrating complication after hypospadias surgery repair is the formation of urethra-cutaneous fistula(fistula is a tract connecting two epithelial surfaces) causing leakage of urine from an unintended site. It occurs after the breakdown of the repair site anywhere from the previous opening site to the tip of penis.
The reported incidence of urethral fistula is around 0 to 30%.
With the development of fistula, the child passes urine through the fistula and from the urethral opening at the tip of penis both. Sometimes all the urine leaks through the fistula if the new urethra becomes tight distal to fistula.
MECHANISM OF FISTULA FORMATION
The two most important factors are Infection and ischemia. Incorporation of urethral mucosa in the ventral repair, irritation and inflammatory reaction to the sutures can also initiates fistula formation
RISK FACTORS
The actual causes of fistula formation remain unknown. Some of the common reasons are technical and avoidable. Fistula risk is high in cases of infection, ischemia, an inadequate procedure, Poor tissue healing, and Distal obstruction due to meatal stenosis/encrustation.
FISTULA PREVENTION
Fistula chances are minimized by following considerations:
- Technical points – use of fine suture with minimal tissue reaction- Fine instruments- Magnification
- Protective intermediate layer – De-epithelialized skin – Tunica vaginalis – Dartez flap – Dorsal subcutaneous preputial flap – External spermatic fascia
- Urethral stenting
- Proper and sterile Dressing
TIMING OF THE REPAIR
After the appearance of fistula, the tissues in the adjacent area are edematous and friable, any attempt to close the fistula at that time will result in further inflammation and much bigger opening.
Ideally no attempt at repair should be carried out for 6-12 months
In case of recurrent fistula, a minimum of one year gap from the previous repair is recommended to allow tissues to heal.
TREATMENT
A number of options are available for closure of fistula depending on the size, location and configuration of fistula. The technique of fistula repair is always chosen wisely after understanding the failure mechanism due to risk of high recurrence. The distal urethra is always examined for strictures or diverticulum to rule out any distal obstruction.
- The small fistula can be managed conservatively with urinary diversion, antibiotics and wound care. They may heal spontaneously in 2-3 weeks’ time.(30% cases approximately)
- Those with fistulas, who do not heal by themselves, need surgery. Surgery usually involves debridement, dissection of the fistula, elaborate excision of the fistulous tract(including the fistula corn) down to healthy thin urethral tissue, closing by inverting suture, and protective intermediate layer closure with robust outer coverage using small skin flap.
- In some recurrent or mega fistulae the two – stage repair is recommended.
FAQs
1. What is the expected outcome?
Outcome depends on the location and size of the fistula and status of surrounding tissues. Although most of the fistula closes after the surgery, some may recur and require further surgery.
2. What is the duration of surgery?
It usually takes less time than the original hypospadias repair and completes in less than an hour.
3. Does it require hospital admission?
The surgery is performed under general anesthesia and as a day care procedure. Patients can go home the same day after recovery from anesthesia.
4. What are the complications?
The most common complication is recurrence of the defect. Others complications include infection, difficulty in urination and stricture formation
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Written by : Dr. Sobia Yasmeen
Copyrights: Pakistan association of Plastic Surgeons