Continuous endoscopic manual suturing for colorectal anastomotic fistula closure

A 54-year-old male underwent a low anterior resection in 2015 for rectal adenocarcinoma. He presented to the emergency department with a two-week history of fever, perianal pain, an erythematous, warm, and actively draining mass. Physical examination revealed a perianal abscess in the left posterior gluteal region, with a palpable internal fistulous orifice 3 cm from the anal margin. Abdominal and pelvic CT and MRI demonstrated a discontinuity in the distal sigmoid colon pre-anastomotic, communicating with a perirectal abscess and an extrasphincteric fistulous tract towards the left ischioanal fat. Despite initial antibiotic therapy with amoxicillin/clavulanic and poor clinical response, colonoscopy revealed a 10 mm, erythematous, and friable fistulous orifice at the anastomosis. Histopathology did not reveal any adenomatous or dysplastic tissue. Vacuum-assisted closure was attempted but was unsuccessful due to technical difficulties and the small size of the cavity. Given the characteristics of the fistula, we proceeded with continuous manual suturing after argon application, achieving complete closure of the fistulous opening. However, after two weeks, there was a sluggish evolution. A follow-up colonoscopy showed persistence of the fistulous orifice with suture material, although radiologically there was a clear decrease in the abscess. Finally, after one month of hospitalization with a stable fistula but no definitive resolution, a planned surgical intervention was decided.