Endocrine Abstracts

Aim: For the surgical treatment of Graves’ Disease (GD), total/near total thyroidectomy is usually preferred over subtotal thyroidectomy due to recurrence risk being low. But in some institutions, subtotal thyroidectomy is preferred due to lower complication rates and for sustaining euthyroidism without the need for replacement. The aim of this study is to analyze the extent of thyroidectomy and its effect on recurrence and complications rates; and in the patients going under subtotal thyroidectomy, study the relationship between remnant thyroid tissue and recurrence.

Methods: Patients who underwent surgery for GD, in a tertiary university hospital between 1987 and 2018 were retrospectively analyzed. Patients who underwent total/near total or subtotal thyroidectomy were grouped as TT and ST respectively. Both groups were compared in terms of demographic characteristics, postoperative complication and recurrent hyperthyroidism rates. In the ST group, patients with or without recurrence were analyzed separately and ROC analysis was used to determine remnant cut-off value. Fisher and chi-square tests were used for categorical analysis while student’s t-test or Mann-Whitney-U tests were used for continuous variables. Significance was determined as P < 0.05

Results: Of the 427 patients included in the study, 125 were in the ST group and 302 were in the TT group. No significant difference was found between the two groups in terms of age and gender (P = 0.5). In the ST group, 10 (8%) patients had recurrent hyperthyroidism while none were seen in the TT group (P < 0.01). Transient hypoparathyroidism was found to be significantly higher in the TT group compared to the ST group (0.8% vs 16.9%; P < 0.01). Persistent hypoparathyroidism (1.6% vs.1%); temporary (0.8% vs. 1%) and permanent (0% vs. 0.3%) vocal cord paralysis rates were comparable. In the ST group, patients with recurrence had higher remnant tissue compared to those who did not (5.3 ± 0.94 g vs.3.4 ± 1.34 g; P < 0.01). In the ST group, the residual tissue cut-off value in terms of recurrence prediction with ROC analysis is found to be 4 g. While no recurrence was seen in the ST group with remnant tissue less than 4 g, patients with remnant tissue ≥4 gr have a recurrence rate of 17.8% (P < 0.01).

Conclusion: In the treatment of GD, the recurrence rates for TT is lower compared to ST without significant increase in long-term complication rates. For patients going under ST, remnant tissue higher than 4 g carries a higher risk of recurrence.