Prospective Analysis of Risk for Hypothyroidism after Hemithyroidectomy

Abstract

Objectives. To evaluate risk factors and to develop a simple scoring system to grade the risk of postoperative hypothyroidism (PH). Methods. In a controlled prospective study, 109 patients, who underwent hemithyroidectomy for a benign thyroid disease, were followed up for 12 months. The relation between clinical data and PH was analyzed for significance. A risk scoring system based on significant risk factors and clinical implications was developed. Results. The significant risk factors of PH were higher TSH (thyroid-stimulating hormone) level and lower ratio of the remaining thyroid weight to the patient's weight (derived weight index). Based on the log of risk factor, preoperative TSH level greater than 1.4 mU/L was assigned 2 points; 1 point was for 0.8–1.4 mU/L. The derived weight index lower than 0.8 g/kg was assigned 1 point. A risk scoring system was calculated by summing the scores. The incidences of PH were 7.3%, 30.4%, and 69.2% according to the risk scores of 0-1, 2, and 3. Conclusion. Risk factors for PH are higher preoperative TSH level and lower derived weight index. Our developed risk scoring system is a valid and reliable tool to identify patients who are at risk for PH before surgery.

Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy

“…In the current study, we also confirmed previous studies that reported the cutoff value of preoperative serum TSH level as 1.7 mIU/L by receiver operating characteristic curve analysis. The cutoff values in previous studies ranged between 1.4 and 2.5 mIU/L (10,11,14,29). Intriguingly, right-side lobectomy associated with postoperative hypothyroidism in the current study might be related to the residual thyroid volume, given that right thyroid lobe is usually bigger than left lobe (30); however, this conclusion is limited as the volume of the resected lobe was not measured.…”

“…Previous studies suggested that preoperative serum TSH level was an important risk factor for hypothyroidism after lobectomy (5,11,27). Higher prelobectomy serum TSH levels might reflect decreased functional reserves in the thyroid gland and might be a critical factor for postoperative hypothyroidism (28).…”

“…Critically, studies investigating risk factors for this postlobectomy complication are not in agreement because of varying follow-up durations, hypothyroidism definitions, thyroid-function assessment timings, and thyroid-hormone-supplementation criteria between the studies (1,(7)(8)(9)(10). Most studies reported that postoperative hypothyroidism developed within the first postoperative year in 90% of patients; however, median follow-up periods in previous studies were relatively short, generally being ,24 months (7,8,(10)(11)(12), which may have underestimated the incidence of postoperative hypothyroidism.…”

Hypothyreose nach Hemithyreoidektomie − überraschend häufige Komplikation während der Nachsorge

“…In Anlehnung an bisherige Untersuchungen wurden für diese Studie die Patienten nach dem postoperativen TSH-Wert in zwei Gruppen eingeteilt: Patienten mit TSH-Werten von über 4.0 mU/L wurden als hypothyreot klassifiziert, solche mit TSH-Werten von 0.4-4.0 mU/L wurden als euthyreot eingeteilt [6]. Die vorliegende Arbeit wurde durch die lokale Ethikkommission (EKNZ2015-022) genehmigt.…”

Electron microscopic study of changes in pancreatic exocrine secretory cells in both early and late stages of hypothyroidism

“…The importance of thyroid pathology has also increased in recent years because of the environmental pollution and iodine deficiency [1,10]. Due to the steady increase in the frequency of thyroid diseases that requires surgery, the problem of postoperative hypothyroidism is becoming increasingly urgent [11]. At the same time, there is very limited information about changes in the structure, and particularly ultrastructure, of pancreatic cells in hypothyroidism.…”