Ultrasound-guided-fine-needle Aspiration Drainage and Percutaneous Ethanol Injection for Benign Neck Cysts

BACKGROUND: Ultrasound-guided-fine-needle aspiration drainage (US-FNAD) and US-percutaneous ethanol injection (US-PEI) have been widely used in the management of benign neck cysts. However, the long-term results of US-FNAD and US-PEI are not well elucidated. METHODS: We retrospectively collated patients under neck US examinations from March 2007 to December 2017 and investigated the recurrence after US-FNAD and US-PEI. Univariate and multivariate Cox regression analyses were used to assess significant risk factors for recurrence after US-FNAD. RESULTS: A total of 1075 patients were recruited, and their age was 50 ± 15 (mean ± standard deviation) years. A total of 862 patients had thyroid cysts, 118 patients had thyroglossal duct cysts (TGDC), twenty patients had branchial cleft cysts, 64 patients had parotid sialocysts, and 11 patients had plunging ranulas. Majority of the patients (97%, 1037/1075) reported significant symptom improvement immediately. However, 38% of the patients had recurrence with a median 3-year follow-up period. In a multivariate Cox regression analysis with adjustment for age and gender, plunging ranula (hazard ratio [HR]: 2.44, 95% confidence interval [CI]: 1.19–4.99) and lateral dimension size ≥ 0.8 cm (HR: 1.32, 95% CI: 1.04–1.67) after US-FNAD were independent risk factors for recurrence. There were 15 male and 19 female patients who received US-PEI therapy after repeated US-FNAD, of whom 23 patients had thyroid cysts, 6 had plunging ranulas, 4 had TGDC, and one had a branchial cleft cyst. The overall success rate was 94% (32/34), with a median follow-up period of 1.6 years. Two recurrent symptomatic patients had plunging ranulas. Some patients stated mild pain (21%, 7/34) and swelling sensation (26%, 9/34) after the injection. No major complications, such as vocal fold paresis or airway compression, were found. CONCLUSION: US-FNAD is an effective tool in the management of benign neck cysts with a 38% recurrence rate. Plunging ranulas have the highest rate of recurrence after FNAD. US-PEI is effective for most recurrent neck cysts after repeated US-FNAD.