Effect of Platelet-Rich Plasma Injection on Wound Healing After Fistulotomy for Simple Anal Fistula Randomized Controlled Trial (RCT)

Effect of Platelet-Rich Plasma Injection on Wound Healing After Fistulotomy for Simple Anal Fistula Randomized Controlled Trial (RCT)

Anal fistula is a common benign anorectal condition characterized by an abnormal tract between the anal canal and perianal skin, often resulting from cryptoglandular infection. Surgical fistulotomy remains the standard treatment for simple low anal fistulas, with success rates exceeding 90% .

However,wound healing following fistulotomy can be prolonged,ranging from 6-10 weeks,which affects patient comfort, quality of life, and return to normal activity (1,2).

After a fistulotomy, the tract is laid open, leaving behind a raw wound extending from the anal canal to the perianal skin.Traditionally,this wound is left open to heal by secondary intention(granulation and epithelialization).

In marsupialization, the cut wound edges (the mucosa and anoderm/skin) are sutured to the wound base.Thismakesthewoundshallowerandkeepsitopenfordrainage.Itpreventsadeepcavitythat would otherwise take longer to granulate and epithelialize.

Marsupialization of the wound edges has been introduced as a modification of standard fistulotomy to improve healing outcomes. Several randomized trials have shown that marsupialization accelerates wound healing (by 1-4 weeks) and preserves sphincter function better compared to leaving the wound open, without increasing recurrence or complications (3,4,5).

Platelet-rich plasma(PRP) has been widely investigated and applied in several surgical fields because of its ability to promote tissue regeneration and accelerate healing. In orthopedic surgery, PRP has been used to enhance bone and tendon healing, particularly in the managementofchronictendinopathiesandfractures.Inplastic and reconstructive surgery,it has been applied to improve graft take, flap survival, and cosmetic outcomes in wound coverage.In maxillofacial and dental surgery, PRP has shown benefits in bone regeneration, implant integration, and periodontal healing. More recently, colorectal and general surgery have explored PRP for difficult-to-heal wounds, including anal fistula, where it has been demonstrated to shorten healing time and reduce recurrence rates

Inclusion Criteria:

• Age18-65years. Both males and females. Clinical diagnosis of simple low anal fistula(confirmed by examination±imaging).

Simple fistula is defined as:

Fistula affecting less than one third of anal sphincter Fistula willnot affect sphincter function after surgery(no risk for fecal incontinence).

All types of low fistula which will not affect anal continence after surgery.

Exclusion Criteria:

• Complex or high anal fistulas:

( multiple tracts, suprasphincteric, extrasphincteric, or high transsphincteric tracts.) -Underlying diseases that impair healing: (Crohn's disease, ulcerative colitis, tuberculosis, HIV infection, anorectal malignancy)

• Hematological disorders: coagulopathy, thrombocytopenia, or platelet dysfunction.
• Systemic factors:

Uncontrolled diabetes mellitus. Immunosuppressive therapy (e.g., steroids, chemotherapy). Previous surgery for anal fistula (to avoid bias from scar tissue and recurrence)..

-Known allergy to any agents used in PRP preparation (rare, e.g., calcium chloride).