Anal fistulas are abnormal tunnels from the anus or rectum usually to the skin near the anus but occasionally to another organ. They may cause pain and discharge, and are often associated with abscesses that, when infected, may produce systemic symptoms. These fistulas tend to occur more frequently in men than in women, and also in people with Crohn’s disease or tuberculosis. They also occur in people with diverticulitis, cancer, or an anal/rectal injury.
Traditionally, surgical intervention is required for anal fistula repair. Although the conventional form of fistula surgery is usually relatively straightforward, the potential for complication exists. This surgery usually involves cutting a portion of the anal sphincter muscle in order to unroof the tunnel, thereby joining the external and internal opening(s) and converting the tunnel into a groove that will then heal from within outward.
Incontinence resulting from partial division or loss of the sphincter muscle is a possible complication of fistula surgery. This has made the need for the development of alternative treatments an important step in optimizing patient care.
At Stony Brook, our colorectal service performs the new minimally invasive repair of anal fistula by means of the anal fistula plug (AFP). This repair is a unique alternative to traditional fistula surgery. The AFP is a conical device made of a natural biomaterial that supports tissue healing. The plug is placed by drawing it through the fistula tract and suturing it in place.
With the AFP, the fistula tract is repaired without cutting the sphincter muscle; thus, the risk of incontinence is minimized. The AFP provides an innovative yet simple treatment. When the AFP is implanted, host tissue cells and blood vessels colonize the “graft.” In essence, the plug provides a scaffold or matrix for the patient's connective tissue growth.
Early clinical results for the anal fistula plug show significant improvement over conventional treatments:
- High percentage of success and greater efficacy shown from early use.
- Minimally invasive procedure.
- Sphincter-saving procedure minimizes risk for postoperative incontinence.
- Suturable biomaterial offers more staying power than fibrin glue.
- Recurrence, while higher rate, does not preclude use of other options or repeat treatment.
Consensus on AFP
In May 2007, Dr. Marvin L. Corman took part in a consensus conference held in Chicago, IL, to develop uniformity of opinion from surgeons who have had considerable experience with the AFP technique in the management of anal fistula. Of the 15 surgeons in attendance, five had performed 50 or more AFP procedures.
The panel members concluded that implantation of the AFP is a reasonable alternative for the surgical management of anal fistula disease, and that a success rate of 50% to 60% should be considered acceptable. In order to achieve the highest probability of success, the panel concluded that patient selection, avoidance of local infection, and meticulous technique are required.
It was further concluded that, outside of the cost, patients should be affected no more adversely than prior to plug implantation, and all other options of management are still available. However, even with observed healing, the recurrence rate is unknown. Ideally, a prospective, randomized trial comparing the AFP procedure with that of conventional fistulotomy will be forthcoming.