Clinical Outcomes of Myasthenia Gravis with Thymoma and Thymic Hyperplasia Undergoing Extended Transsternal Thymectomy: A Single-Center Experience

Background: Despite the widespread use of thymectomy in myasthenia gravis (MG) patients, it has remained controversial as to whether this procedure is of a similar efficacy and clinical outcome among MG patients with thymoma and thymic hyperplasia. Aim: We sought to determine the long-term clinical outcomes of MG patients who received extended transsternal thymectomy associated with pyridostigmine and prednisolone postoperatively. Materials and Methods: In a retrospective study from January 1999 to December 2013, MG patients who underwent thymectomy were followed up. Out of 41 MG patients admitted in our center, 25 patients had undergone thymectomy adjunctive to pyridostigmine and prednisolone therapy postoperatively. The primary endpoints included improvement in individual diplopia, ptosis, dysphagia, dysarthria, dyspnea, and limb weakness. In addition, according to the MG Foundation of America (MGFA) criteria, response to therapy was defined as complete stable remission (CSR), pharmacologic remission (PR), and minimal manifestation (MM) as secondary endpoints. Results: Majority of the patients were male (60%) and the mean age of the patients was 32.2 +/- 13.9 years. Fifteen (60%) and 10 patients (40%) had thymoma and thymic hyperplasia, respectively. All the patients were followed up during a mean period of of 86.9 +/- 50.3 months (minimum 10 months and maximum 168 months). The rates of CSR, PR, and MM were comparable between the thymoma and thymic hyperplasia groups (P = 0.584). Based on the Kaplan Meier analysis, the probabilities of CSR, PR, and MM were not significantly different between patients with thymoma and thymic hyperplasia. Conclusion: The extended transsternal thymectomy, along with the postoperative regimen of pyridostigmine and prednisolone was associated with a high rate of clinical improvement among MG patients with thymoma or thymic hyperplasia.