Association of obesity and thyroidectomy-specific perioperative outcomes.

Background: There is limited large-scale data on the effect of obesity on thyroidectomy-specific outcomes. To fill this gap in the literature, this study evaluates the association between obesity and thyroidectomy-specific outcomes using a large real-world surgical outcomes dataset.

Materials and methods: The 2016-2019 American College of Surgeons National Surgical Quality Improvement Program Targeted Thyroidectomy dataset (ACS NSQIP) was queried. Using an inverse probability weighted (IPW) model, the impact of BMI on the primary (postoperative voice hoarseness, neck hematoma, and hypocalcemia.) and secondary outcomes (operative time and postoperative length of stay) were estimated. BMI was evaluated as per the WHO obesity categories. Sensitivity analysis was performed.

Results: 24,370 patients were evaluated with an average BMI of 30.6, a mean age of 51.8 years, 77.5% were female, and 7.9 % were Hispanic. In univariate analysis, patients with BMI >30 had a higher risk of postoperative voice hoarseness (6.7 vs. 5.8% and p = 0.005) and neck hematoma (2.1 vs. 1.7% and p = 0.014) and a lower risk in hypocalcemia rates (3.6% vs. 4.6 % and p < 0.001). In the fully adjusted multivariable IPW models, BMI >30 was associated with a higher rate of postoperative voice hoarseness (RR 1.12 and p = 0.031) and neck hematoma (RR 1.25 and p = 0.024) but a lower rate of hypocalcemia (RR 0.81 and p = 0.001). Also, patients with BMI >30 had longer OR time (adjusted difference: 6.33 min and p < 0.001) and length of stay (adjusted difference: 1.36 h and p = 0.002).

Conclusion: In this national cohort of patients undergoing thyroidectomy, obesity was associated with a decreased rate of hypocalcemia but an increased rate of postoperative voice hoarseness and neck hematoma.