Current guidelines recommend transcervical thymectomy (TCT) during parathyroidectomy (PTX) for Multiple Endocrine Neoplasia Type 1 (MEN1)-associated primary hyperparathyroidism (PHPT) despite limited evidence substantiating efficacy. We aimed to determine the role of TCT in disease control and safety outcomes.

A systematic review and meta-analysis were conducted on comparative observational studies exploring the efficacy of PTX with or without concomitant TCT for managing PHPT in patients with MEN1. Pooled event proportions were estimated using Freeman-Tukey double arcsine transformation method and converted to relative risk. Six studies (n = 306 patients) were included.

TCT showed significantly reduced rates of persistent (relative risk 0.15; 21.9% vs. 3.1%; p < 0.01) and recurrent PHPT (RR 0.34, 43.8% vs. 12.9%; p = 0.004) necessitating re-operation compared to PTX alone, suggesting improved disease control. Interestingly, the addition of TCT reduced rates of transient PHPT (RR 0.07; 9.3% vs. 0%; p < 0.01 and permanent recurrent laryngeal nerve injury (RR 0.32, 3.9% vs. 1.0%; p = 0.04), indicating possible benefits in morbidity.

Concomitant TCT may improve the safety and efficacy of PTX in MEN1-associated PHPT by synergistically clearing all cervical disease and minimizing adverse sequelae. Our findings provide further evidence to support existing recommendations for TCT and can guide surgical decision-making.