Abstract

Background Complex fistula-in-ano is a challenging anorectal condition characterized by multiple tracts, high fistulas, recurrent disease, and proximity to sphincter muscles. Conventional surgical approaches risk sphincter damage, incontinence, and recurrence. Kshara Sutra Therapy (KST), an Ayurvedic minimally invasive technique using medicated setons, has been recognized for decades as an effective option for fistula management. Objective To review the evidence base for Kshara Sutra therapy in complex fistula-in-ano, discuss technical innovations, and contextualize its mechanism and outcomes within both Ayurvedic and modern surgical frameworks. Methods A narrative review was conducted using databases including PubMed, Google Scholar, DHARA, AYUSH Research Portal, and key surgical journals. Traditional Ayurvedic texts (Sushruta Samhita, Ashtanga Hridaya) and recent clinical trials, case series, and systematic reviews were analyzed. Results Kshara Sutra therapy demonstrates high healing and low recurrence rates in complex fistulae when compared to conventional fistulotomy/fistulectomy, particularly in high anal fistulas and recurrent cases. Innovations such as modified setons (Guggulu/Triphala coated), preoperative imaging guidance, and improved postoperative care have enhanced outcomes. Mechanistic evidence suggests gradual chemical cauterization, fibrosis, and drainage as critical components of healing. Conclusion Kshara Sutra therapy is a viable, sphincter-preserving approach for complex fistula-in-ano with robust clinical evidence. Integrative surgical practice incorporating Kshara Sutra may reduce morbidity and recurrence. Future directions include standardization and multicenter RCTs.