ISSN 2348–392X BMH Med. J. 2014;1(1):3-8 Research Article

Background: Risk factors for post hemithyroidectomy (HT) biochemical hypothyroidism (BH) and its course are not well understood. The aim of the study was to look at the incidence, risk factors and the course of BH after HT Material and Methods: Longitudinal observational study at a tertiary care referral centre. Patients undergoing HT (Jan to Dec 2009), having a follow up for 2 years, with no history of head and neck radiation and euthyroid pre op status were included. Serum TSH, FT4, TPO Ab, Anti Tg Ab, FNAC and USG thyroid are performed pre operatively. Post operatively the residual thyroid volume was assessed using USG at 1 week. TSH was performed at one, three, six, twelve months after surgery. Statistical analysis: SPSS vs. 12 used and appropriate statistical tests applied Results: Patients (n=92) satisfied the inclusion criteria (14 males and 78 females). The mean age, duration of the goiter, TPO Ab and serum Anti Tg Ab levels were 38.58 ± 9.98 years, 35.08 ± 49.39 months, 43.87 ± 85.7 IU/mL and 2.65 ± 2.28 IU/mL respectively. BH was observed in 43.48% (n=40). Patients who had BH after HT were older, had significantly lower residual thyroid volume and smaller sized involved lobe. Patients with thyroiditis had a relative risk of 1.97 for post operative BH. At one year 23.33 % (n=21) had BH. Conclusions: Post hemithyroidectomy BH is common in older patients with lesser amount of residual thyroid volume. 50 % of these recover spontaneously within the first year after surgery necessitating monitoring of thyroxine replacement. Key Words: Hemithyroidectomy, hypothyroidism, thyroid volume, thyroiditi