Total versus subtotal thyroidectomy. Arguments, approaches, and recommendations.

Arguments for routine total thyroidectomy or routine, less than total resection have been espoused for treatment of well-differentiated intrathyroidal carcinoma. Numerous reports in the literature support either approach. No prospective randomized studies have been performed, partly because of the indolent nature of the disease. Many reports are also complicated by the failure of the authors to divide patients into high-risk and low-risk groups and to categorize and evaluate fully the histologic types of the resected tumors. Good evidence exists to show that in the majority of cases of intrathyroidal, well-differentiated lesions, bilateral subtotal resection yields results that compare favorably with total thyroidectomy. Logically, at least, a total thyroidectomy would seem to be preferable, because subtotal resection can be imprecise. Therefore, subtotal thyroidectomy can be recommended over total thyroidectomy, if only on the basis of comparison of complications. The type and rate of complications vary among surgeons. Each thyroid surgeon, therefore, must establish an individual complication rate. Total thyroidectomy in inexperienced hands is not recommended. We recommend, therefore, that total thyroidectomy be used selectively by surgeons who have the skill and experience necessary to make the decision intraoperatively. If, for example, during resection of the lobe that contains the primary tumor, the laryngeal nerves and parathyroid glands can be clearly identified and if there is minimal bleeding and trauma, the surgeon may proceed to side two to perform a total thyroidectomy. If the lesion is large, however, with distortion of anatomy, dissection may be difficult even for an experienced surgeon. Intracapsular parathyroids or undiscovered parathyroids on the side of initial resection should prompt the surgeon to perform a subtotal resection on side two. Under these circumstances, the surgeon should not feel that a total thyroidectomy justifies the increased risk. A unilateral resection, such as lobectomy plus isthmusectomy, can be performed with satisfactory long-term results in low-risk patients, that is, in those with small (less than 1.5 cm) unilateral intrathyroidal exposure and in those with no evidence of metastatic disease. Alternately, the AGES criteria of Hay et al can be used to identify patients in low- or high-risk groups. If the decision to perform a bilateral resection is based on the previous criteria, we recommend that a total thyroidectomy be performed only by an experienced surgeon. During surgery, if there is any suggestion that the laryngeal nerves or parathyroid glands would be at increased risk if a total resection were performed, it may be necessary to revert to a subtotal procedure.(ABSTRACT TRUNCATED AT 400 WORDS)