Diagnosis and Treatment of Transsphincteric Perianal Fistulas

textabstractFistula’ is the Latin word for a reed, pipe or flute. In medicine it implies a chronic granulating track connecting two epithelium lined surfaces. These surfaces may be cutaneous or mucosal. Perianal fistulas run from the anal canal to the perianal skin or perineum. Perianal fistulas are associated with considerable discomfort and morbidity to the patient. The two principal goals in the treatment of perianal fistulas are eradication of the fistulous tract and preservation of sphincter function. In patients with an intersphincteric fistula, these objectives can be achieved by laying open the fistulous tract. Although this procedure affects anal pressure, the functional results are quite satisfactory. The management of fistulas, crossing the upper two-thirds of the external anal sphincter, however, remains a difficult surgical challenge. Treatment of these high transsphincteric fistulas by a traditional laying open technique will lead to an almost complete transsection of a substantial part of the external anal sphincter with wide separation of both ends. To prevent this, several techniques have been developed. Accurate preoperative assessment of perianal fistula is necessary for planning the most suitable surgical procedure and therefore enables the surgeon to inform the patient on the type of surgery and its possible complications. Based on the findings of this thesis, it is concluded that: (1) The results of 3D endoanal sonography enhanced with hydrogen peroxide and endoanal magnetic resonance scanning are comparable. (2) The outcome of transanal mucosal advancement flap repair is successful in 75 percent of all patients. This technique is a worthwhile treatment for perianal fistulas. (3) Fecal incontinence after transanal mucosal advancement flap repair is caused by the use of a Parks’ anal retractor, not by inclusion of fibers of the internal anal sphincter. (4) The anocutaneous advancement flap repair is not a viable alternative to the transanal mucosal advancement flap repair, since the results are moderate to poor. Furthermore, the incidence of impaired continence is comparable to that after transanal mucosal advancement flap repair. (5) Smoking of cigarettes adversely affects the outcome after transanal mucosal advancement flap repair. (6) The healing rate of transanal advancement flap repair of low rectovaginal fistulas is poor (less than 50 percent). (7) The results of transanal advancement flap repair of low rectovaginal fistulas can not be improved by the addition of a labial fat flap transposition