"Feasibility and Safety of the Calcium Alginate Hydrogel Sealant for the Treatment of Cryptoglandular Fistula-in-ano: Phase I/IIa Clinical Trial"

"Feasibility and Safety of the Calcium Alginate Hydrogel Sealant for the Treatment of Cryptoglandular Fistula-in-ano"

Background: Complex perianal fistulas pose a challenge to surgeons since the fistulous tract must be eliminated without impairing continence. Biological sealants have emerged as an effective alternative for maintaining the integrity of the anal sphincter. The investigators aimed to assess the feasibility and safety of calcium alginate hydrogel injections into the tract as treatment for complex cryptoglandular fistulas.

Methods: A prospective, single-center, case series of this novel technique was conducted in a level 3 hospital, including patients diagnosed with trans-sphincteric perianal fistulas and treated with a calcium alginate hydrogel sealant. A strict follow-up was performed by an independent surgeon at 1, 3, 6, and 12 months. The main outcome measures were feasibility, safety (number of adverse events) and efficacy of the treatment.

Inclusion Criteria:

• Signed Informed Consent Form
• Age ≥18 years
• Cryptoglandular PAF treated by Seton placement for at least 3 months, with a single External Fistulous Orifice and Internal Fistulous Orifice

Exclusion Criteria:

• Informed Consent Form not signed or withdrawn
• Not possible to adhere to follow-up routine
• Another investigational drug in the previous 3 months
• Allergy to alginate
• Grade IV in American Society of Anesthesiologists scale
• Pregnancy
• History of radiotherapy in the perineal area
• Diagnosis or suspicion of Intestinal Blow Disease
• Immunosuppression, active neoplasia at the time of recruitment or in previous year, or positive for human immunodeficiency virus Internal Fistulous Orifice not located during the procedure
• Simple anal fistula (submucosa or low Intersphincteric Perianal Fistula, except association with Faecal Incontinence
• Anal stenosis that prevents exploration
• Undrained collections >2 cm
• Rectovaginal fistulas
• Fistulas of non-cryptoglandular origin