Surgical treatment for Graves’ disease Subtotal or Total Thyroidectomy? Dr. Chun-Fan KU Department of Surgery Pamela Youde Nethersole Eastern Hospital

Treatment of Graves’ disease Antithyroid medication I131 ablation Surgery

Surveys of the European and American Thyroid Associations 1987,1990

Antithyroid medication Requires long treatment duration Low permanent remission rates Side effects

I131 ablation Pregnancy or lactation Children ?severe ophthalmopathy ?large goitre May requires >1 dose of I131 Eventually developed hypothyroidism

Surgical indications --Suspect malignancy --Desiring pregnancy --Local compression --Fear of irridation --Children --Poorly compliant patients --Cosmetic --Severe Graves’ ophthalmopathy --Need of rapid symptom control --Roe SM J Am Coll Surg 2001

Subtotal vs Total Thyroidectomy Simpler operation with lower complication rates --recurrent laryngeal nerve injury --parathyroid injury Achieves a low recurrence rate while maintaining euthyroidism

Subtotal vs Total Thyroidectomy Complication rates Subtotal n=6703 Total n=538 p value Temporary RLN palsy 2.8% 7.7% >0.05 Permanent RLN palsy 0.7% 0.9% Temporary hypoparathyroidism 7.4% 9.6% Permanent Hypoparathyroidism 1.0% --Palit TK. J. Surg. Res. 2000

Thyroid function after Subtotal Thyroidectomy Hypothyroidism% Recurrence% Farnell 100 75 1 Dominello 184 69 3 Menegaux 215 49 4 Sugino 728 46 15 Chou 205 44 7 Kasuga 134 42 17 Noguchi 325 8 Noh 14

Instability of thyroid function after Subtotal Thyroidectomy 79% of patients change thyroid status during follow up period of 8-12yrs --Kuma K. Am J Med Sci 1991

--Dominello A. Asian J of Surg. 2000

Predictability thyroid function after Subtotal Thyroidectomy TSH receptor antibody Lymphoid infiltration Antimicrosomal and other antithyroid antibodies

wt of residual thyroid (g) Remnant size 8.9% decline in the rate of hypothyroidism for each gram of thyroid remnant --Palit TK. J. Surg. Res. 2000 wt of residual thyroid (g) Recurrence rate (%) 6-8 23.8 4 9.4 <2 --Hermann M. Surgery. 1998

Graves’ ophthalmopathy Theoretical advantage of downregulating the autoimmune response of ophthalmopathy by removal of persistent antigenic stimulation after total thyroidectomy Protosis improvement of –0.9mm vs +0.5mm --Kurihara H. Thyroid.2002

Total Thyroidectomy Comparable permanent complication rates Predictable outcome in terms of thyroid function No risk of recurrence (need for life long thyroxine replacement)

Conclusion Surgeon’s preference Patient’s choice between chance of recurrence and life long thyroxine replacement