Impact of Branch vs. Truncal Ligation of Inferior Thyroid Arteries on Post-Thyroidectomy Hypocalcaemia:

A Meta-Analysis of Controlled Trials

Abstract

Background: Hypoparathyroidism following a thyroidectomy remains a significant clinical challenge for an endocrine surgeon. Recently, it has been proposed by some endocrine surgeons that truncal ligation may lead to a higher incidence of postoperative hypocalcemia, while others have refuted this notion by citing no long-term impact on incidence of hypoparathyroidism. This study aims to compare the effect of truncal versus branch ligation of inferior thyroid arteries on postoperative hypocalcaemia.

Data Sources: Articles were identified using the MeSH, and Free Keyword searches “Thyroid”, “Truncal Ligation” and “Hypocalcaemia” in PubMed, Embase, PubMed Central, Cochrane library, Latin American and Caribbean Health Sciences Literature database and Google Scholar.

Methods: Randomized and nonrandomized controlled trials of patients who underwent subtotal/total thyroidectomy, completion thyroidectomy and thyroidectomy with neck dissection were searched, and outcomes of truncal ligation versus branch ligation of inferior thyroid arteries were compared. Quality of methods of randomized controlled trials were reviewed in accordance with Cochrane Collaboration Guidelines on RevMan and non-randomized controlled trials were assessed with Newcastle-Ottawa Quality Scale. Meta-analysis was performed using a random effects model, and pooled results shown as risk differences. The primary outcome was transient postoperative and definite hypocalcaemia.

Results: We found 13 randomized controlled trials (RCT) and 11 nonrandomized controlled trials (non-RCT) with 2580 patients: 1267 patients belonged to trunk ligation group and 1261 to the branch ligation group. The risk difference of symptomatic hypocalcaemia was 8% (95% CI :3% to 12%), for biochemical hypocalcaemia; 8% (95%CI:  4% to 13%), and for definite hypocalcaemia was 0% (95% CI: -1% to 1%).

Conclusion: An increase in the risk of transient postoperative hypocalcaemia is observed following truncal ligation, compared to branch ligation of the inferior thyroid arteries, with no significant risk difference in definite hypoparathyroidism.