Abstract: Objective To observe the postoperative efficacy and complications of endoscopic low-temperature plasma ablation for congenital piriform sinus fossa fistula(CPSF)in children with different inflammatory stages and explore the selection of surgical indications and the judgment of postoperative cure criteria. Methods The clinical data of 45 patients with congenital pyriform sinus fistula treated in our department in the past 3years were retrospectively analyzed. According to the clinical characteristics, it was divided into early infection, abscess, and inflammatory quiescence stages. All children were treated with low-temperature plasma under endoscopic guidance. The curative efficacy was observed. Results All children were followed up for 6 months to 3 years. A total of 33 cases(73.3%)were cured. In 17 cases, the secondary endoscopic exploration was completed, the internal fistula was closed, and no abnormalities were found on a postoperative B-ultrasound examination. Sixteen children underwent only B-ultrasound follow-up and no second surgical exploration, and no abnormalities were noted. Eleven cases(24.4%)improved. None underwent a second endoscopic exploration, and postoperative B-ultrasound follow-up showed microtubule residue but no clinical symptoms during more than 6 months of follow-up. One case(2.3%)was not cured. In this case, endoscopic exploration was completed, the internal fistula was closed, and a B-ultrasound reexamination showed microtubule residue. The neck of the affected side became re-infected 7 months postoperative, but it recovered after antibiotic treatment. The patient was followed up for 1 year without recurrence and remains under surveillance. Four children had early inflammation; of them, 2 had neck abscesses soon after surgery that were cured after incision and drainage. Among 15 cases in the abscess stage, no neck infection occurred during postoperative follow-up. Among the 26 children in the inflammatory quiescence stage,1 had recurrent neck swelling on the affected side at 7 months postoperative that recovered after anti-infective treatment. One patient(inflammatory quiescence stage)developed hoarseness postoperatively and recovered after 1 month of follow-up, while the rest had no complications. Conclusion Endoscopic low-temperature plasma ablation for the treatment of CPSF fistula in the period of quiescent inflammation and acute infection is effective, safe, and minimally invasive, making it the first choice for the initial treatment of CPSF.

Key words: Congenital pyriform sinus fistula, Endoscopic, Low temperature plasma, Curative effect