Measuring the Efficacy of Thymectomy for Pediatric Myasthenia Gravis Across Tertiary Children's Hospitals.

BACKGROUND: Thymectomy is a treatment for pediatric myasthenia gravis, but the efficacy over time is unknown. Multi-institutional data are also lacking. Therefore, the objective of this study was to determine the efficacy of thymectomy for pediatric myasthenia gravis using medication burden and health care utilization as proxies for disease severity.

METHODS: This was a cross-sectional study of the Pediatric Health Information System database among children who underwent thymectomy at one of 49 children's hospitals from 2004 to 2022. Differences in annual median number of doses of myasthenia-related medications, admissions, and health care costs in the year before thymectomy to three years after were compared. A comparison cohort that did not undergo thymectomy was utilized. Medians were compared using the Wilcoxon signed-rank test. Generalized linear regression estimated the effect of surgical approach on outcomes.

RESULTS: A total of451 patients (238 patients who underwent thymectomy and 213 nonthymectomy patients) were identified. Following thymectomy, the decrease in annual median total number of myasthenia-related doses was 12.0 (interquartile range: 6 to 31) (P < 0.001). The decrease in number of annual admissions was 2.0 (1 to 4) (P < 0.001), which represented a cost difference of $5292 ($3533 to $8681) (P < 0.001). No differences were observed in the control cohort. In a generalized linear regression model, surgical approach was not associated with the efficacy of thymectomy (P = 0.55).

CONCLUSIONS: Thymectomy is an effective treatment for pediatric myasthenia gravis, evidenced by the decreased medication burden and health care utilization after surgery. Surgical approach did not influence the success of surgery. Thymectomy should be considered earlier in the treatment algorithm.