The effectiveness of parathyroid gland autotransplantation in preserving parathyroid function during thyroid surgery for thyroid neoplasms: A meta-analysis

Objective We conducted this meta-analysis to assess the effectiveness of parathyroid gland auto transplantation in preserving parathyroid function during thyroid surgery for thyroid neoplasms. Methods We conducted a search by using PubMed, Embase, and the Cochrane Library electronic databases for studies that were published up to January 2019. The reference lists of the retrieved articles were also reviewed. Two authors independently assessed the methodological quality and extracted the data. A random-effects model was used to calculate the overall combined risk estimates. Publication bias was evaluated with a funnel plot using Egger's and Begg's tests. Results A total of 25 independent studies involving 10,531 participants were included in the meta analysis. Compared with patients who did not undergo parathyroid gland autotransplantation, the overall pooled relative risks for patients who underwent parathyroid gland autotransplantation were 1.75 (95% CI: 1.51-2.02, p<0.001) for postoperative hypoparathyroidism, 1.72 (95% CI: 1.45-2.05, p<0.001) for protracted hypoparathyroidism, 1.06 (95% CI: 0.44-2.58, p = 0.894) and 0.71 (95% CI: 0.22-2.29, p = 0.561) for biochemical hypoparathyroidism and biochemical hypocalcemia at 6 months postoperatively, respectively, and 1.89 (95% CI: 1.33-2.69, p<0.001) and 0.22 (95% CI: 0.09-0.52, p = 0.001) for biochemical hypoparathyroidism and biochemical hypocalcemia at 12 months postoperatively, respectively. The pooled relative risks for patients who underwent one parathyroid gland autotransplantation and patients who underwent two or more parathyroid gland autotransplantations were 1.71 (95% CI: 1.25-2.35, p = 0.001) and 2.22 (95% CI: 1.43-3.45, p<0.001) for postoperative hypoparathyroidism, 1.09 (95% CI: 0.59-2.01, p = 0.781) and 0.55 (95% CI: 0.16-1.87, p = 0.341) for hypoparathyroidism at 6 months postoperatively compared with those of patients who did not undergo parathyroid gland autotransplantation. Conclusions Parathyroid gland autotransplantation is significantly associated with increased risk of postoperative and protracted hypoparathyroidism, and the number of autoplastic parathyroid glands is positively correlated with the incidence of postoperative hypoparathyroidism.