Analysis of extended thymectomy for the treatment of myasthenia gravis of 527 cases / 中华胸心血管外科杂志

ABSTRACT

Objective:To summarize the surgical treatment experience of extended thymectomy for myasthenia gravis(MG), and to explore the surgical treatment of MG.Methods:Retrospectively analyzed the clinical data of 527 MG patients undergoing extended thymectomy in our hospital from June 1996 to October 2017, including 242 males and 285 females, aged 5 to 77 years, with a mean age of(52.6±13.7) years old. The course of illness was 12 days to 18 years. There were 22 cases of hyperthyroidism, 7 cases of pure red blood cell aplastic anemia, 1 case each of hypothyroidism, irritable bowel disease, rheumatoid arthritis, ankylosing spondylitis and thrombocytopenia syndrome. There were 272 cases of MG in Osserman Ⅰ, 72 cases inⅡa, 78 cases inⅡb, 81 cases in Ⅲ, and 24 cases in Ⅳ, respectively. The muscle fatigue test and neostigmine test of all patients were positive, and the diagnosis was confirmed by chest CT examination. Meanwhile, summarize the perioperative data and postoperative follow-up.Results:3 cases died during the postoperative period, all of which were thymoma with MG, including 2 cases of Osserman Ⅲ MG and 1 case of Ⅳ MG; 15 cases of postoperative myasthenia crisis, including 2 OssermanⅡb cases, 11 Osserman Ⅲ cases and 2 Osserman Ⅳ cases, also including 7 cases of tracheotomy; 70 cases of plasma exchange, of whom 2 cases of hypotonic syndrome and 2 cases of lower extremity venous thrombosis. The postoperative pathological types were followed by thymic hyperplasia 293 cases(55.60%), thymoma 207 cases(39.28%), thymic cyst 24 cases(4.55%) and thymic atrophy 3 cases(0.57%) in descending order. 378 cases were followed up with an average follow-up of(85.9±58.5)months; MG with complete remission, partial remission, no change and deterioration accounted for 135(35.71%), 192(50.79%), 41(10.85%) and 10(2.65%)cases, respectively. Complete remission rate ranked as Osserman typeⅠ>Ⅱa>Ⅳ>Ⅱb>Ⅲ, the deterioration rate from high to low was Osserman type Ⅲ>Ⅳ>Ⅰ. 18 OssermanⅠcases showed no effects, whose preoperative course of disease> 5-10 years; 1 OssermanⅠcase was worsening who initially was diagnosed with ophthalmic MG and underwent video-assisted thoracoscopic thymectomy. The left thymus lobe was left unresected and developed 6 years later. Another operation was performed to remove the left lobe thymus, confirming the compensatory hypertrophy of the left lobe thymus. Among the worsening patients, 6 died, all of them were thymoma with MG, including 5 cases of type Ⅲ and one case of type Ⅳ. The cause of death was omyasthenia crisis(3 cases), sudden respiratory arrest after 3 months of rapid stopping of brompistigmine(2 cases)and cholinergic crisis(1 case).Conclusion:Standardized extended thymectomy is an effective method for the treatment of MG. Earlier surgery for ocular muscle type MG can effectively reduce the risk of generalization. MG with Osserman Ⅱb or higher is prone to myasthenia crisis. Comprehensive treatments should be taken to reduce MG-related risks. Myasthenia crisis can occur repeatedly in severe patients in the long term after surgery, requiring regular medication and comprehensive MG treatments.