Does the ultrasound dissector improve parathyroid gland preservation during surgery?

BACKGROUND: The most common complication of thyroid surgery is hypoparathyroidism, usually temporary. Ischemic injury or parathyroid avulsion are the causes of surgical hypoparathyroidism. We assessed the value of an ultrasound scalpel, the Harmonic Focus(®) (HF), could prevent surgical-related hypoparathyroidism. METHODS: Patients consecutively undergoing total thyroidectomy using the HF from November 2009 to February 2011 were recruited and their clinical characteristics, type of operation, histology, and postoperative calcium levels (normal range: 2.10-2.55 mMol/l) were recorded. The prevalence of transient and permanent hypocalcemia was calculated for benign vs. malignant diseases and compared with a control group of 147 patients treated surgically in 2005 using manual technique. RESULTS: 139 patients treated by the same surgeon with a total thyroidectomy (41.7% for a malignant disease) were considered. Prevalence of transient hypoparathyroidism (THP) was 45.2% and of definitive hypoparathyroidism (DHP) 1.4%. None of the patients with malignancies were hypocalcemic at 1-year follow-up. In the control group THP was found in 51.7% of cases and DHP in 5.4% (p < 0.001). CONCLUSIONS: Use of the ultrasound scalpel improved the likelihood of the parathyroid glands preservation during thyroid surgery. Paradoxically, the HF appears to be more effective in treating malignant disease, i.e. when central node dissection is required.