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

Abstract

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. 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. 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. 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.