Objective - To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of hyperthyroidism caused by bilateral hyperplastic thyroid nodules in cats. Design - Prospective study. Animals - 7 cats. Procedure - Hyperthyroidism was diagnosed on the basis of clinical signs and increased serum total thyroxine (Π4) concentrations. The presence of 2 cervical thyroid nodules was confirmed by use of ultrasonography and technetium Tc 99m albumin thyroid scans. After the death of 1 cat that received PEI in both thyroid nodules at the same time, the protocol was changed to injecting ethanol into 1 nodule at a time, with at least 1 month between injections. Clinical signs, serum Π4 concentrations, serum ionized calcium concentrations, laryngeal function, findings on ultrasonographic examinations of the ventral cervical region, and results of thyroid scans were monitored. Results - Serum Π4 concentrations transiently decreased in all 6 cats (into the reference range in 5 of 6 cats) within 4 days of the first staged ethanol injection. Each subsequent injection resulted in a transient decrease in serum Π4 concentration. The longest period of euthyroidism was 27 weeks. Adverse effects included Homer's syndrome, dysphonia, and laryngeal paralysis. One cat died of unrelated causes. One cat underwent bilateral thyroidectomy, 2 cats were treated with methimazole, and 2 cats that had increased serum Π4 concentrations were not treated further, because they remained clinically normal. Conclusions and Clinical Relevance - Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of the American Veterinary Medical Association|
|State||Published - Apr 15 2001|
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