The procedure was developed by Thai colorectal surgeon, Arun Rojanasakul, The first reports of preliminary healing result from the procedure were 94% in 2007. Additional ligation of the intersphincteric fistula tract did not improve the outcome after endorectal advancement flap. Fistula clip closure (OTSC Proctology) is a recent surgical development, which involves the closure of the internal fistula opening with a superelastic clip made of nitinol (OTSC). During surgery, the fistula tract is debrided with a special fistula brush and the clip is transanally applied with the aid of a preloaded clip applicator. The surgical principle of this technique relies on the dynamic compression and permanent closure of the internal fistula opening by the superelastic clip. Consequently, the fistula tract dries out and heals instead of being kept open by continuous feeding with stool and fecal organisms. This minimally-invasive sphincter-preserving technique has been developed and clinically implemented by the German surgeon Ruediger Prosst. First clinical data of the clip closure technique demonstrate a success rate of 90% for previously untreated fistulae and a success rate of 70% for recurrent fistulae. VAAFT is a surgical kit for treating anal fistulae. The system comprises:
A video telescope (fistuloscope) to allow surgeons to see inside the fistula tract. A unipolar electrode for diathermy of the internal tract. This is connected to a high frequency generator. A fistula brush and forceps for cleaning the tract and clearing any granulation tissue.The VAAFT procedure is done in 2 phases, diagnostic and operative.
Grade I & II are simpler fistulas and can be managed by Fistulotomy whereas Grade III-V are complex fistulas in which fistulotomy should be not be done. They should be managed by Fistula experts. Unlike Parks and St James University Hospital Classification, this correlation is quite accurate with Gargs classification. Therefore this new classification is useful to both surgeons and radiologists. Types
Depending on their relationship with the internal and external sphincter muscles, fistulae are classified into five types:

Extrasphincteric fistulae begin at the rectum or sigmoid colon and proceed downward, through the levator ani muscle and open into the skin surrounding the anus. Note that this type does not arise from the dentate line (where the anal glands are located). Causes of this type could be from a rectal, pelvic or supralevator origin, usually secondary to Crohns disease or an inflammatory process such as appendiceal or diverticular abscesses. Suprasphincteric fistulae begin between the internal and external sphincter muscles, extend above and cross the puborectalis muscle, proceed downward between the puborectalis and levator ani muscles, and open an inch or more away from the anus. Transphincteric fistulae begin between the internal and external sphincter muscles or behind the anus, cross the external sphincter muscle and open an inch or more away from the anus. These may take a U shape and form multiple external openings. This is sometimes termed a horseshoe fistula. Intersphincteric fistulae begin between the internal and external sphincter muscles, pass through the internal sphincter muscle, and open very close to the anus.