Prevalence of hypothyroidism among patients with isthmus-preserved thyroid lobectomy.

Objective To investigate the prevalence of hypothyroidism following thyroid lobectomy with isthmus preservation. Methods This retrospective, case series study included patients who had undergone thyroid lobectomy with preserved isthmus that was reversed onto the contralateral lobe. Neck ultrasound was performed in all patients and the patients were followed for 2 years. Results Out of 170 patients enrolled into the study, three were excluded due to preoperative hypothyroidism and one due to isthmusectomy; of the remaining 166 included in the final analyses, 139 patients (83.7%) were female, 27 (16.3%) were male, and patient age ranged between 17 and 77 years. The indication for intervention was thyroid swelling in 141 patients (84.9%). Final diagnoses following histopathological examination comprised benign lesion in 145 cases (87.3%), malignancy (follicular carcinoma and papillary thyroid carcinoma) in 12 cases (7.2%) and thyroiditis in nine cases (5.4%). During the 2-year post-surgery follow-up, 165 patients (99.4%) were euthyroid and one patient (0.6%) developed hypothyroidism. Conclusion Postoperative hypothyroidism following thyroid lobectomy appears to be very rare when the isthmus is preserved and reversed onto the contralateral lobe.