Pig Plugs

A State-of-the-Art Idea for Treating Fistulas
David N. Armstrong, M.D., FRCS, FACS, FASCRS
Program Director, Georgia Colon and Rectal Surgical Clinic, Atlanta, GA

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A “fistula” is defined as an abnormal channel between any two epithelial-lined tracts of the body. The most common fistulas occur in the anorectal region as a result of infection in “anal glands” (the same glands your dog has!). The resulting abscesses drain via the skin in the perianal region and result in fistulas. Fistulas cause pain, constant drainage, and the risk of repeat abscess formation. These so-called “crypto glandular fistulas” are very common, and approximately 100,000 fistula surgeries are performed per year in the US. Similarly, rectovaginal fistulas may develop from complications of childbirth, or GYN surgery. Worldwide, rectovaginal fistulas are the most common fistula in humans. The cause is often a result of inadequate health-care in third world countries which can result in unmanaged pregnancies and unsupervised delivery, subsequently leading to childbirth trauma.
One of the most debilitating forms of fistula is caused by Crohns disease. Crohns disease is an inflammatory disease which can occur anywhere in the intestine, and the resulting fistulas may invade any organ in the body – bladder, uterus, another segment of the gut – or drain onto the body’s skin surface. Depending on where these fistulas erode, Crohns fistulas are one of the most difficult challenges in modern medicine, and may cause a multitude of life-threatening complications.





Conventional surgery for anorectal fistulas consists of surgically “laying open” the fistula tract (fistulotomy), but this often results in sphincter damage and resulting incontinence. Alternatively, a surgical drain “seton” may be inserted through the tract, to prevent abscess formation. Unfortunately these setons are usually required lifelong, and the patient experiences continued drainage from the tract as well as discomfort.

In 2003, I began making small plugs out of 2x3 cm sheets of Surgisis® ESTM Soft Tissue Grafts, to close anorectal fistulas and rectovaginal fistulas. The simple premise was to develop a “biological” plug, which could be inserted into the entrance to the fistula, and close the tract in exactly the same manner as putting a plug in a hole, or a cork in a bottle. Surgisis, derived from a layer (submucosa) of pig small intestine, is composed of an “extracellular matrix” that is gradually repopulated by the host’s cells.

Preliminary studies were published in March 2006 reporting successful closure of 87% of anorectal fistulas using the new plug. Most exciting was the discovery that, in our early experience, the Surgisis plug was successful in closing 80% of Crohns fistulas, so seriously impacting one of the most serious challenges facing Crohn’s patients.

The new plug also offers the additional benefits of little or no discomfort after surgery (the plug is simply sutured in the fistula tract), and most important, the plug avoids the need to divide or cut any tissue whatsoever. This therefore avoids the risk of sphincter damage, and eliminates the potential of incontinence – a dramatic leap forward in surgery of fistulas.

It is early days and exciting times for the Surgisis plug. Engineers at Cook are collaborating with surgeons in many specialties – Urology, Plastics, Bariatrics, and Gynecology, to develop innovative and imaginative ways of using Surgisis plugs to close the many kinds of fistula which afflict mankind. Unique delivery systems are under development to allow surgeons to deploy the plugs into abdominal fistulas, such as entercutaneous fistulas, to make an otherwise dangerous and complex abdominal surgery as simple as corking a bottle.