Aims: Percutaneous aspiration and ethanol injection (PEI) is effective in managing predominantly cystic (>50% cystic) thyroid nodules with efficacy ranging from 38-85%. We aimed to evaluate efficacy, safety, and factors determining outcomes of PEI in managing simple cystic (purely cystic) vs. complex cystic (having both cystic and solid components) thyroid nodules.
Materials and methods: Predominantly cystic thyroid nodules, without any ultrasonography and/or fine needle aspiration, evidence of malignancy were aspirated ultrasonography guided. Sterile 100% ethanol (50-100% volume aspirated) was injected and reviewed monthly for 3 months and thereafter 3 monthly. Responders were defined as ≥ 50% reduction in nodule volume.
Results: Sixty-five patients out of 152 considered underwent PEI. Sixty patients [simple cystic (42) and complex cystic (18)] with mean follow-up of 12.3 ± 2.88 months were analyzed. Response rate of PEI was 78.33% [simple cystic (92.86%) and complex cystic (44.44%) nodules; P < 0.001]. Also, 31.67% patients achieved remission at 1(st) month. And, 46.67% patients achieved remission between 1-6-months follow-up. Kaplan Meier analysis showed significantly improved outcomes in patients with simple cystic nodules (P < 0.001). Cox-regression revealed type of nodule (simple cystic vs. complex cystic) to be predictive of outcome (P = 0.034). Complex cystic nodules were 67.6% less likely to go into remission, compared to simple cystic nodules. Baseline nodule size, aspirate, or volume of ethanol injected did not predict outcome.
Conclusions: PEI is safe and should be treatment of choice for simple cystic thyroid nodules. PEI for complex cystic thyroid nodules are associated with lower response, increased recurrence, and need for repeated PEI.
Keywords: Complex cystic nodule; percutaneous ethanol ablation; simple cystic nodule thyroid cyst.