Fat Tissue Treatment Shows Promise for Complex Anal Fistula

Nearly 74% of Patients Healed Without Repeat Surgery

Anal fistulas are abnormal tunnels that form between the anal canal and the skin near the anus. Complex anal fistulas involve a significant portion of the sphincter muscles that control bowel movements. This makes them difficult to treat without risking incontinence. In this pilot study, researchers tested whether injecting specially processed fat tissue from the patient's own body could help these challenging fistulas heal safely.

First-Time Patients Saw Better Results Than Those with Prior Failures

The study included 19 patients with complex transsphincteric anal fistulas. Researchers divided them into two groups. Group I had 12 patients receiving this treatment as their first sphincter-saving procedure. Group II had seven patients who had already failed other sphincter-saving treatments. After an average follow-up of nine months, 83.3% of first-time patients healed completely. Among those with prior failed treatments, 57.1% achieved healing. The overall healing rate across both groups was 73.7%.

Procedure Used Patient's Own Processed Fat Tissue

The treatment used Lipogems® technology to process fat tissue harvested from the patient's abdomen. Doctors first collected fat using a gentle liposuction technique with local numbing solution. The fat was then processed in a special device that breaks it into tiny fragments while removing blood and oils that could cause inflammation. This micro-fragmented adipose tissue (specially processed fat) contains pericytes (helper cells that support healing) and mesenchymal stem cells (regenerative cells that aid tissue repair).

Treatment Combines Fat Injection with Fistula Tract Repair

All patients first had a loose seton (a thread placed through the fistula) for four to six weeks before the main procedure. During the treatment, surgeons cleaned out the fistula tract and closed the internal opening with stitches. They then injected about 10 milliliters of the processed fat tissue around the internal opening and throughout the fistula tract. The entire procedure took an average of 55 minutes.

Minimal Pain and Few Complications Reported

Patients reported very low pain levels after surgery. On a scale of zero to ten, the average pain score was just two. The study recorded no serious complications such as:

• Postoperative fever

• Abdominal infection

• Bleeding from the treatment area

• Loss of bowel control

Only minor issues occurred. Three patients developed small bruises on their abdominal wall where fat was collected. These resolved without treatment. One patient developed a perianal abscess requiring additional care.

What This Means for Your Treatment Decision

This pilot study suggests that micro-fragmented adipose tissue injection may offer a safe option for complex anal fistula. The procedure uses your own tissue, reducing the risk of rejection or allergic reactions. It avoids cutting through sphincter muscles, which helps protect bowel control.

However, this was a small study with 19 patients and follow-up averaging nine months. Larger studies with longer follow-up are needed to confirm these findings. If you have had previous failed treatments, your success rate may be lower than for first-time patients. Discuss with your doctor whether this approach suits your specific situation, including the type and location of your fistula.

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Source: Naldini et al., Techniques in Coloproctology, 2018.