Purpose: To clarify the efficacy of a right-sided video-assisted thoracoscopic extended thymectomy (RtVATET) as a surgical alternative for myasthenia gravis (MG) and to determine the optimal timing for a thymectomy.
Methods: Thirty-three patients who underwent RtVATET in two institutes were enrolled in this study. Another 66 paired, traditional trans-sternal extended thymectomy (TET) patients from the registered database were used to compare these two surgical modalities for MG.
Results: Mean blood loss was 88.5 ml in RtVATET and 226.8 ml in TET group patients (P < 0.001). Mean operation duration was 207.3 min for RtVATET and 172.8 min for TET patients (P = 0.003). Complete stable remission (CSR) rates and total improvement rates for the RtVATET and TET patients were 42.4% vs 60.6% (P = 0.087) and 87.9% vs 90.1% (P = 0.637), respectively. Furthermore, when we focused on the minor grades (classes I and IIa), TET groups showed significantly better CSR than the RtVATET groups (P = 0.012), but there was no statistically significant difference for the more severe grades (classes IIb and III, P = 0.827).
Conclusion: Both RtVATET and TET are effective for treating MG, although this study does indicate an advantage for TET. We suggest that a thymectomy should therefore be performed earlier, or that the procedures should be extensive enough to remove all of the tissue that contains thymic tissue.