VATS thymectomy for myasthenia gravis: a retrospective review of 500 cases

Objective To review video-assisted thoracoscopic thymectomy as a treatment for myasthenia gravis (MG),compare outcomes of thoracoscopic thymectomy for thymoma and non-thymoma MG,and assess the efficacy of Video-assisted Thoracoscopic Extended Thymectomy (VATET) combined with mediastinoscopy.Methods A retrospective review of 500 patientswith MG who underwent VATS thymectomy between 2001 and 2011 has been done.They were divided into three groups:118 cases of thymoma MG group,thoracoscopy for non-thymoma MG group 301cases,and VATET for non-thymoma MG group 81cases.Results There was no mortality.Thoracoscopic thymectomy was successfully performed for 495 cases.In the thoracoscopy group for non-thymoma MG,the operating time is (111.3 ± 31.6) min,11.0％ having post-operative myasthenic crises ; in the VATET group,the operating time is (145.0 ± 71.6) min,9.9％ having post-operative myasthenic crises ;in the thymoma MG group,the operating time is (128.5 ± 77.8)min,24.6％ having post-operative myasthenic crises.During the follow-up,CSR was 37.3％,36.5％ and 28.7％ in the groups of thoracoscopy for non-thymoma MG,VATET and thymoma MG respectively.However,the disease-free survival curve shows that CSR of the thymoma MG group became lower than other two groups 3 years after surgery,and CSR of the VATET group becoming higher than that of thoracoscopy for nou-thymoma MG group 5 years after surgery.CSRs of groups of thoracoscopy for non-thymoma MG,VATET and thymoma MG might reach 50％,60％ and 36％.Conclusion The VATET combined with mediastinoscopy has a better long-term outcome because the more thymus might be removed comparing with non-thymoma MG,thoracoscopic thymectomy for thymoma MG had a worse long-term outcome. Key words: Myasthenia gravis;  Thymoma ;  Surgical procedures, minimally invasive ;  Thymectomy