[Analysis of 15 children with type Ⅳ branchial cleft cyst treated with endoscopic transoral approach].

<b>Objective:</b> To analyze the clinical characteristics and endoscopic surgical procedures of the second branchial cleft cyst type Ⅳ in children. <b>Methods:</b> A retrospective review was conducted on 15 pediatric cases with type Ⅳ second branchial cleft cysts treated at the Beijing Children's Hospital affiliated with Capital Medical University and Henan Children's Hospital from September 2019 to November 2023. All patients underwent excision via a two-person, three-hand endoscopic transoral approach. The cohort included 12 males and 3 females, with an age range of 10 months to 10 years and 5 months, and a median age of (59.20±32.05) months. The clinical data of initial symptoms, sides, imaging features, treatment methods, complications, length of hospital stay, prognosis and outcome were recorded and analyzed. SPSS 22.0 software was used for statistical analysis. <b>Results:</b> Of the 15 children, 13 cases presented with snoring as the primary symptom, 1 case with dysphagia, and 1 case was asymptomatic and was found unintentionally. The mean disease duration was (6.74±9.05) months (range, from 3 days-2 years). MRI revealed cystic lesions on the right side in 12 cases and on the left side in 3 cases, characterized by uniform long T2 signal, equal T1 or short T1 signal. The cysts appeared dumbbell-shaped in 10 cases with the pharyngeal constrictor muscle as the waist, the posterior outside of the mass was adjacent to the internal carotid artery. The remaining 5 cases showed an isolated cyst located inside the pharyngeal constrictor muscle. The intraoperative MRI findings were consistent. Partial cystectomy was performed in 10 cases near the internal carotid artery, leaving only the portion with a clear arterial pulse intact. Five cases with isolated cysts on the medial side of the pharyngeal constrictor muscle were totally removed. The average length of hospital stay was (4.53±0.52) days (4-5 days). All patients were followed up for 7-56 months [median (30±15.12) months] with no recurrence of symptoms observed. <b>Conclusions:</b> The second branchial cleft cyst type Ⅳ in children is characterized by prominent pharyngeal cystic mass, with snoring as a predominant initial symptom, MRI provides excellent diagnostic value. The two-person, third-hand endoscopic transoral approach for cyst excision is feasible, safe, and offers the benefits of minimal invasiveness and reduced hospitalization time.