Thymectomy in myasthenia gravis via original video-assisted infra-mammary cosmetic incision and median sternotomy: long-term results in 180 patients

Objective: The clinical outcome of 180 non-thymomatous myasthenia gravis (MG) consecutive cases surgically treated is reported herein. The original surgical access, consisting of a video-assisted infra-mammary cosmetic incision and median sternotomy, has originally been designed and described by our group. Methods: The in-hospital patients' charts and the outpatients' clinic follow-up information of the 180 cases have been extensively reviewed. In addition to the strictly surgical benchmark referral, data on the rate of cure of the MG (complete stable remission - CSR; pharmacological remission - PR) as indicated by the Myasthenia Gravis Foundation of America (MGFA) have been analysed as recorded at the 12 months after surgery checkpoint. Cosmetic outcome was evaluated as well. Results: Female to male ratio was 156 (86.7%):24 (13.3%). Mean age: 29.1 ± 10.9 years. Preoperative MGFA score: stage I: 4 patients (2.2%); IIa: 57 (31.7%); IIb: 32 (17.8%); IIIa: 41 (23.3%); IIIb: 42 (23.3%); IVa: 2 (1.1%); V: 2 (1.1%). Median operative time was 110 min (70-130 min) and median postoperative hospital stay was 4 days (3-10 days). Postoperative mortality was nil and morbidity occurred in seven patients (3.8%). Final pathology was consistent with: 146 hyperplastic thymus (81.1%); 28 involuted thymus (15.6%) and 6 normal thymus (3.3%). Ectopic thymic tissue was found in 68% of the patients. Mean follow-up was 62.9 ± 34.6 months. A CSR was obtained in 55%; PR in 18.3%; improvement in 39.9%, unchanged in 3.5%, worse in 1.1% and died in 0.5%. Kaplan-Meier estimates of CSR were 34.1% and 75.8% at 5 and 10 years, respectively. The preoperative therapy was the only parameter significantly associated with Kaplan-Meier CSR rates (univariate analysis - p <0.001). Remarkably, 171 (95%) patients judged their cosmetic results to be excellent or very good. Conclusions: Thymectomy in MG patients via video-assisted infra-mammary cosmetic incision and median sternotomy has shown to be a useful surgical approach as demonstrated by the good functional and very good aesthetic results, associated with a very low morbidity and no mortality. Patients with preoperative mono-therapy have higher CSR rates. CSRs are durable, as the CSR rate improves with extended follow-up.