[Prognostic factors of thyroid function following surgical therapy in Graves-Basedow's disease].
BACKGROUND
The goals of this work are to describe late thyroid function and to determine predictive factors of permanent hypothyroidism following surgery in Graves-Basedow's disease.


METHODS
From 1979 to 1999, 107 patients with hyperthyroidism due to Graves-Basedow's disease underwent subtotal thyroidectomy. We performed life-table analysis and calculated the cumulative incidence of hypothyroidism by means of the Kaplan-Meier's method. Survival (euthyroidism)within patients groups was compared using the Mantel-Cox method. Variables influencing long-term thyroid function were determined by estimating the Odds ratio with a logistic regression model.


RESULTS
The probability of euthyroidism among all 107 patients at 240 months was 51.4%.Age, gender, duration of both hyperthyroidism and antithyroid therapy and weight of resected thyroid tissue did not influence the eventual outcome. The weight of thyroid remnant was 5.4 (1.5)g and the conditional logistic regression analysis showed that weight of thyroid remnant was the only variable influencing long-term thyroid function. Hyperthyroidism relapsed in 5 patients.


CONCLUSIONS
In our experience,surgery represents a definitive alternative treatment with a risk of hypothyroidism within the first 2 years of 43.9%. The weight of thyroid remnant is the only variable influencing long-term thyroid function.
Amat
M
M
Cirugía General y Digestiva. Hospital Prínceps d'Espanya. Ciutat Sanitària i Universitària Bellvitge, L'Hospitalet de Llobregat, Barcelona.
Gómez
J M
JM
Biondo
S
S
Rafecas
A
A
Jaurrieta
E
E
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006111:Graves Disease / Q000601:surgery*; D006801:Humans; D007037:Hypothyroidism; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis; D013960:Thyroid Function Tests; D013965:Thyroidectomy