Detection and Management of Hypothyroidism Following Thyroid Lobectomy: Evaluation of a Clinical Algorithm

Abstract

The incidence of hypothyroidism following TL is low, and a significant proportion of individuals who become biochemically hypothyroid will demonstrate only a transient elevation in their TSH levels. As well, individuals with LI, or GC formation, within their resected thyroid lobe may be at increased risk for post-TL hypothyroidism.

Hypothyroidism After Hemithyroidectomy: Incidence, Risk Factors, Natural History and Management

“…Routine thyroxine replacement may be recommended, rather than close follow-up monitoring, for some posthemithyroidectomy patients with risk factors, such as elevated thyroid antibody concentrations or histologic evidence of autoimmune thyroiditis (Su et al, 2009). In contrast, other researchers have reported that elevated serum TSH concentration alone may not justify the initiation of thyroid hormone replacement, since nearly 70% of individuals who developed biochemical (asymptomatic) hypothyroidism during the early postoperative period after hemithyroidectomy recovered normal thyroid function without pharmacologic intervention (Johner et al, 2011). Therefore, determination of the true indication is important prior to initiating thyroid hormone replacement therapy.…”

“…However, hypothyroidism after hemithyroidectomy is an under-reported or underwww.intechopen.com recognized complication, with patients most often monitored only for a short time postoperatively. Recently, however, Johner et al (2011) reported that the overall incidence of early postoperative hypothyroidism was 21.6%, with the incidence of permanent hypothyroidism only 7.8%. In addition to showing that the incidence of hypothyroidism following hemithyroidectomy is low, this study showed that a significant proportion of individuals who become biochemically hypothyroid (asymptomatic) demonstrate only a transient elevation in their TSH levels.…”

“…Although closer monitoring or earlier initiation of thyroid hormone replacement therapy may be advisable for these high-risk patients, no specific TSH concentration alone is indicative of increased risk of permanent or overt hypothyroidism, suggesting that transient biochemical hypothyroidism be closely monitored rather than routinely treated. Accurate detection and diagnosis of sustained hypothyroidism after thyroid surgery is also important to avoid its associated morbidity and mortality (Johner et al, 2011).…”

“…The degree of lymphocytic infiltration, graded on a scale of 0-IV, into the resected thyroid lobe may aid in predicting the development of hypothyroidism in post-hemithyroidectomy patients (Koh et al, 2008). An extensive review of histopathologic data, which assessed whether the degree of lymphocytic infiltration and germinal center formation within the thyroid lobe could accurately predict the development of postoperative hypothyroidism, found that when inflammation was graded based on the extent of lymphocytic infiltration (graded 0-3) and the frequency of germinal centers was qualitatively assessed as a histologic measure of immunologic activation (graded 0-3), most patients with lymphocytic infiltration or germinal center formation in the resected thyroid lobe are at increased risk for posthemithyroidectomy hypothyroidism (Johner et al, 2011). Other studies have assessed the relationship between postoperative pathologic findings and risk of developing hypothyroidism, but, since these findings were detected after surgery, they could not be used to determine the need for postoperative thyroidectomy.…”

“…A recent modification of an earlier algorithm (Johner et al, 2011) recommended that TSH be measured 6 and 12 months after hemithyroidectomy, indicating that the measurement of TSH at 3 months was no longer required because most study participants displayed marked increases in serum TSH concentration immediately after surgery, which subsequently normalized over time. This new algorithm recommended that serum TSH be measured biannually in asymptomatic patients with mild biochemical hypothyroidism (TSH 5.6-6.9 uIU/L).…”