Notice from the American Board of Thoracic Surgery

Sixty-five patients with thymomatous myasthenia gravis were investigated. Thymomas were present in 44% of the male patients and 19% of the female patients with myasthenia gravis. The incidence of thymomatous disease in male patients was higher than in female patients in all age groups. Eighty percent of men more than 50 years old and women more than 60 years old had myasthenia gravis with thymoma. Germinal center formation in the thymus of patients with thymomatous myasthenia gravis was positive in 91% and was high grade.The prognosis for patients undergoing extended thymectomy of thymomatous myasthenia gravis was significantly better than in those having transsternal simple thymectomy, but it was worse than the prognosis for patients with nonthymomatous myasthenia gravis. No increase in the rate of remission or palliation was seen one year after thymectomy. It is concluded that early thymectomy is effective in control of myasthenia gravis in thymomatous myasthenia gravis.     

Surgical treatment for myasthenia gravis.

A new surgical technique for thymectomy is presented. Three hundred and seventeen patients with myasthenia gravis and 20 with thymomas who had myasthenic symptoms were operated on. The new surgical approach--a small transverse sternotomy--was used in 257 cases (in 240 patients with myasthenia gravis and 17 with thymomas) and conventional median sternotomy in 80. In myasthenic patients small transverse sternotomy enabled radical thymectomy to be performed with an uneventful postoperative course and very good cosmetic results. There were no hospital deaths among patients with myasthenia gravis after thymectomy. The long term results, assessed after 18-24 months, were good: the total remission rate was 39.5%, and there was a great improvement in 48.5% and an improvement in 9%. After thymectomy about 30% of patients received supplementary treatment with prednisone. A correlation between the duration of symptoms and the result of thymectomy was established: the shorter the duration of myasthenia gravis the better the results. In the small group of 20 patients with thymomas two died in hospital. In 12 patients with encapsulated thymic tumours the long term results were similar to those in patients with myasthenia gravis, whereas in patients with infiltrating thymic tumours the results were unsatisfactory.     

影响重症肌无力患者术后疗效的危险因素分析

目的探讨影响重症肌无力患者胸腺切除术后疗效的因素。方法136例重症肌无力患者行胸腺切除术,采用相对记分法进行术后疗效评定;选择6个可能影响重症肌无力患者行胸腺切除术后疗效的临床因素,包括性别、年龄、术前病程等,将各因子有关资料进行量化赋值,采用有序反应变量累积log it模型,分析各因素对术后疗效的影响。结果重症肌无力患者的性别、年龄和术前病程对术后疗效有明显的影响,而临床分型、胸腺的病理改变类型和术前胆碱酯酶抑制剂用量对术后疗效的影响无统计学意义。结论重症肌无力患者术后症状的缓解和改善会受到一些危险因素的影响,对患者预后的评估应适当考虑这些因素;早期诊断、早期手术治疗能提高疗效,缩短改善症状的时间。     

Association of IgA nephropathy and myasthenia gravis

Three patients with IgA nephropathy associated with myasthenia gravis are described. In all 3 cases, myasthenia gravis emerged after the discovery of glomerulonephritis. Myasthenic symptoms were improved by thymectomy in 2 cases, but progression of the renal disease was not improved. Some systemic abnormalities, including immunological aberrations, were observed in these two disorders. It is postulated that T cell abnormalities in IgA nephropathy might be independent of the development of myasthenia gravis.     

Appearance of thymoma 15 years after extended thymectomy for myasthenia gravis without thymoma.

Several cases of thymoma recurrence after resection have been reported. However, thymoma appearance following an extended thymectomy for non-thymomatous myasthenia gravis is very rare. We report a case of thymoma in a 48-year-old woman, 15 years after an extended thymectomy for non-thymomatous myasthenia gravis. The importance of a complete dissection of mediastinal adipose tissue during the extended thymectomy as well as careful follow-up for such patients is also noted.     

Thymectomy in the treatment of ocular myasthenia gravis

BACKGROUND: Thymectomy is an effective and accepted treatment for myasthenia gravis, but thymectomy for ocular myasthenia gravis (Osserman stage I) is controversial. OBJECTIVE: To assess the efficacy and propriety of thymectomy for the treatment of ocular myasthenia gravis. METHODS: We conducted a review and follow-up of all patients who had thymectomy for the treatment of ocular myasthenia gravis between 1970 and 1998 at the University of California, Davis, Medical Center, and the University of Rome, "La Sapienza," Rome, Italy. Patient response to thymectomy was categorized as follows: cured, patients who became symptom-free and required no further medication; improved, patients who required less medication and whose symptoms were less severe; unchanged, patients whose symptoms and medications were the same; worse, patients who had more severe symptoms, needed more medication, or died. RESULTS: Sixty-one patients (mean age 37 years; range 14-73 years) were followed up for a mean duration of 9 years (range 0.5-29 years). Ocular myasthenia gravis with mixed and cortical thymomas, stages I to IV, occurred in 12 patients, and ocular myasthenia without thymomas occurred in 49 patients. Transsternal thymectomy (n = 55) and transcervical thymectomy (n = 6) resulted in cure in 31 (51%) patients, improvement in 12 (20%) patients, no change in 16 (26%) patients, and worsening of symptoms (including 1 postoperative death) in 2 patients. Patient outcomes were statistically independent of the duration of preoperative symptoms (mean 9.5 months), patient age, or the presence or absence of thymoma. In patients with ocular myasthenia, 70% were cured or improved after thymectomy; in the subgroup of patients with ocular myasthenia and thymoma, 67% were cured or improved. CONCLUSION: Thymectomy is an effective and safe treatment for patients with ocular myasthenia gravis.     

A case report of extended thymectomy in an elderly patient with myasthenia gravis associated with Hashimoto's disease

We experienced a case of late-onset myasthenia gravis associated with Hashimoto's disease. A 74-year-old female with chief complaints of extremities acratia and hypohidrosis was diagnosed as having myasthenia gravis by the Tensilon test. In addition severe hypothyroidism was noted, and histological examination of a thyroid biopsy revealed Hashimoto's thyroiditis. Extended thymectomy was carried out, and the postoperative course was uneventful due to administration of an anti-ChE drug and a thyroid hormone. This case is extremely rare because only 10 patients with late-onset (over 70 years old) myasthenia gravis have been reported in the literature in Japan, and only three of them were associated with Hashimoto's disease. It was suggested that, in cases of myasthenia gravis in elderly patients, we should take into consideration radical therapy including thymectomy as a positive approach to treatment.     

Clinical and pathologic predictors of outcome in thymoma-associated myasthenia gravis

BACKGROUND: Myasthenia gravis is by far the most common paraneoplastic syndrome of thymomas. There is little information regarding the influence of clinical variables and thymoma-associated factors on biologic development of myasthenia gravis. The aim of the study was to determine independent predictors of clinical outcome in thymoma with myasthenia gravis. METHODS: We studied 108 patients with thymoma-associated myasthenia gravis undergoing removal of the mediastinal mass between 1967 and 2000. Clinical and pathologic variables associated with clinical outcome of myasthenia were assessed by multivariate Cox regression analysis. RESULTS: Patients were followed for a mean period of 10 years (9 months to 33 years). A total of 38 patients died (35.2%), in 14 cases (37%) because of myasthenia gravis and in 6 (16%) because of recurrence of thymoma. With respect to clinical outcome of myasthenia gravis, at the end of the follow-up period, the rate of remission was 16% (n = 17). Of the 91 patients in whom remission was not achieved, 55 had no symptoms with immunosuppressive medication and 36 had symptoms with medication. CONCLUSIONS: In patients with thymoma-associated myasthenia gravis, well-differentiated thymic carcinoma (Müller-Hermelink system), age more than 55 years, and interval from the onset of symptoms to thymectomy of less than 1 year were found to be independent predictors of nonremission of myasthenia gravis after thymectomy.     

胸腺切除治疗重症肌无力的远期疗效

目的 探讨胸腺切除治疗重症肌无力的远期疗效。方法 １９９０年４月地１９９４年８月胸腺切除治疗重症肌无力１２４例中,１０４例获得远期随访随访期平均为２３．６个月。患者平均年龄２９．２岁。术前病程平均为３４．２个月。按改良Ｏｓｓｅｎｎａｎ标准分为Ⅰ型２９例、Ⅱ型６４例、Ⅲ型１１例。随访疗效评价分优、良、无效和差。结果 总有效率为８２．７％,无效１３．５％,差１．９％,２例死亡,手术疗效与临床分型,术前     

机器人胸腺和胸腺瘤切除术

目的总结用达芬奇S（Da Vinci S）机器人行胸腺和胸腺瘤切除术治疗重症肌无力的情况,观察其安全性及手术效果。方法 2009年5月25日至2011年4月30日,使用D avinci S机器人系统,连续完成胸腺和胸腺瘤切除并行胸腺周围脂肪组织清扫术19例。结果 19例患者均手术成功,无中转开胸,出血少,恢复快,除1例术后出现肌无力危象外无其他并发症发生。结论机器人行不开胸胸腺和胸腺瘤手术安全可行,效果确切。     

经胸腔镜胸腺扩大切除术治疗重症肌无力42例报告

目的总结胸腔镜胸腺扩大切除治疗重症肌无力的经验。方法42例重症肌无力患者行胸腔镜或胸腔镜辅助小切口手术,切除范围包括胸腺组织及前上纵隔的脂肪软组织。结果手术均顺利完成,全组均无中转开胸。平均手术时间116.3（65-165）min,术中平均出血量为81.7（52-110）ml,术后平均住院时间为8.5（6-16）d。术后发生重症肌无力危象2例,予机械辅助通气及对症处理后好转。术后病理示26例为胸腺增生,16例为胸腺瘤。35例获随访,平均27.2（4-43）月,完全缓解7例,改善27例,1例无明显改善。结论胸腔镜胸腺扩大切除治疗重症肌无力,方法可行、可靠,具有创伤小、恢复快的优点。     

Cervical thymectomy in the treatment of myasthenia gravis

Treatment modalities in myasthenia gravis consist of surgery, chemotherapy and plasmapheresis. Thymectomy can be accomplished either through a median sternotomy or through a small, transverse cervical incision. Forty patients who underwent cervical thymectomy for non-thymomatous myasthenia gravis were studied retrospectively. Twenty-six patients (65%) showed a favourable response to thymectomy and there were statistically significant improvements in myasthenic symptoms and reductions in medication requirements. Age, sex, duration of symptoms and thymic histology were not predictive of response to thymectomy. Operative mortality was zero and operative morbidity was minimal. During the last 6 years, only two of 22 patients required admission to the intensive care unit postoperatively. The postoperative hospital stay ranged from 2 to 23 days. Cervical thymectomy does not preclude later sternotomy in those patients who fail to respond favourably. We therefore recommend cervical thymectomy as the initial surgical procedure in the treatment of non-thymomatous myasthenia gravis.     

Contemporary Management of Myasthenia Gravis: The Clinical Role of Thymectomy

Thirty-six patients with myasthenia gravis have been evaluated and treated over the past five years. Eleven patients had ocular myasthenia gravis and responded well to anticholinesterase medications. Twenty-five patients had generalized myasthenia gravis, and 22 of them were initially treated with anticholinesterase medications; 18 (82%) failed to improve or to maintain an initial improvement on medication, and 14 of these 18 patients underwent thymectomy. In addition, 3 patients underwent thymectomy as part of their initial treatment during the later part of this study. All thymectomies were performed through a median sternotomy.All 17 patients manifested sustained improvement as judged by a gain in strength and decrease in medications. Thymectomy is beneficial in the treatment of myasthenia gravis, and it is most efficacious when performed early in the course of the disease.     

Effects of thymectomy in myasthenia gravis.

Factors influencing onset of remission in myasthenia gravis were evaluated in 2062 patients, of whom 962 had had thymectomy. Multivariate analysis showed that appearance of early remissions among all patients was significantly and independently influenced by thymectomy, by milder disease, and by absence of coexisting thymomas. Patients with mild generalized symptoms treated with thymectomy reached remission more frequently, even when compared with those with ocular myasthenia treated without surgery. Short duration of disease before thymectomy in mild cases was another factor associated with earlier remissions. Mortality for all patients was significantly and independently influenced by severity of symptoms, age, associated thymomas, and failure to remove the thymus. Patients without thymectomy and with thymomas had, in addition, earlier onset of extrathymic neoplasms. Morbidity after the transcervical approach was minimal. This study demonstrates that early thymectomy by the transcervical approach, when technically feasible, has significant clinical advantages over the transthoracic approach and should be advocated for all patients with myasthenia gravis, including those with ocular disease.     

Surgical outcome of thymectomy for myasthenia gravis

Background The medical treatment for myasthenia gravis has been reported to have remission rates as low as 15%. Thymectomy on the other hand has been reported to have clinical remission rates up to 80% and therefore has become the accepted mode of treatment. Methods 57 patients diagnosed with myasthenia gravis underwent thymectomy at the Christian Medical College and Hospital, Vellore from January 1994 to December 2003. The aim of this study was to determine the outcome for myasthenia gravis after thymectomy. Results Our results indicated that female sex had a better over all prognosis, Ossermann stage, I, IIA, & III was associated with higher incidence of complete clinical remission and the response to thymectomy decreased with increasing Ossermann stage. Post operative medication requirement reduced significantly as compared to the preoperative requirement. Conclusion We therefore conclude that trans-sternal thymectomy was found to be beneficial to all patients of mild to moderate myasthenia gravis, with 70.2% patients showing improvement postoperatively. We also advocate thymectomy for ocular myasthenia gravis.     

电视胸腔镜胸腺扩大切除治疗重症肌无力107例临床分析

目的探讨电视胸腔镜下胸腺扩大切除术治疗重症肌无力的临床效果。方法对1995年6月至2004年6月,台湾长庚纪念医院胸外科和北京大学人民医院胸外科根据临床表现及肌电图检查诊断证实为单纯重症肌无力,行电视胸腔镜胸腺完整切除及前纵隔脂肪组织廓清术治疗的107例患者的临床资料进行回顾分析。结果术后随访1—98个月,完全缓解34例,改善55例,全组完全缓解及改善率为83％,无手术死亡病例。结论电视胸腔镜下手术切除胸腺及前纵隔脂肪组织治疗重症肌无力临床效果良好,安全,创伤较小。     

Thymectomy for myasthenia gravis

Opinion statement No Class I studies of the effectiveness of thymectomy for myasthenia gravis (MG) have been performed. Most Class II studies comparing outcomes in MG patients with and without thymectomy demonstrated higher MG remission and improvement rates in patients undergoing thymectomy. However, these Class II studies were also consistently confounded by important differences between MG patients in surgical and nonsurgical groups. Myasthenia gravis patients undergoing thymectomy were younger, more often women and were more likely to have severe myasthenia. The authors of this paper cannot determine from these Class II studies whether the observed association between thymectomy and improved MG outcomes was a result of a thymectomy benefit or was merely a result of the multiple differences in baseline characteristics between the surgical and nonsurgical groups. The authors concluded that the benefit of thymectomy in non-thymomatous autoimmune MG has not been conclusively established. Thus, for patients with non-thymomatous autoimmune myasthenia gravis, thymectomy should only be considered an option to increase the probability of remission or improvement. The quality standards subcommittee of the American Academy of Neurology recently adopted this position [1].     

Experience with programmed steroid treatment with thymectomy in nonthymomatous myasthenia gravis

BACKGROUND: The benefit of thymectomy in myasthenia gravis management is recognized but the perioperative course can fluctuate. The goal of this study was to assess the feasibility and clinical benefit of dose-escalated steroid therapy with thymectomy for nonthymomatous myasthenia gravis. METHODS: We reviewed the records of 69 myasthenia gravis patients who were followed up after undergoing transsternal thymectomy with extended anterior mediastinal dissection in our hospital between 1976-2000. Forty-eight patients in the programmed treatment group who had dose-escalated and de-escalated steroid therapy during the perioperative period comprised 17 patients with ocular myasthenia gravis and 31 patients with generalized myasthenia gravis. Clinical benefits and clinical remission, which was diagnosed when the patients were symptom-free without medications for at least 1 year, were compared with those of 21 patients in the occasional treatment group who received medications occasionally over the perioperative period. RESULTS: Postoperative respiratory failure and myasthenic crisis did not occur in the programmed treatment group but did occur in 6 patients in the occasional treatment group. Remission rates in the programmed treatment group (mean follow-up, 6.4 years) were 30% at 3 years, 38% at 5 years, and 46% at 10 years; rates in the occasional treatment group (mean follow-up, 9.6 years) were 25% at 3 years, 25% at 5 years, and 45% at 10 years. CONCLUSIONS: Programmed steroid therapy in patients with nonthymomatous myasthenia gravis is feasible and it provides clinical benefit when fluctuating symptoms occur during the perioperative period.     

Long-term outcome and quality of life after open and thoracoscopic thymectomy for myasthenia gravis: analysis of 131 patients

Background  Myasthenia gravis is an autoimmune disease with a great impact on quality of life. Besides conservative treatment with mestinon and immunosuppressive medication, thymectomy is an established intervention that offers substantial improvements of the disease. Since the past decade, minimally invasive procedures have been performed. This study aimed to report on the long-term results for all the patients who underwent thymectomy for myasthenia gravis, paying special attention to postoperative disease-related outcome, quality of life, and differences regarding the operative approach. Methods  This report describes a series of 131 patients with generalized myasthenia gravis who underwent thymectomy between 1980 and 2005. The clinical course data during the hospitalization and consultation in our outpatient clinic were reviewed, and survival data were generated. The patients were seen in the outpatient clinic, where a modified Osserman and quality-of-life score was evaluated at the end of the follow-up period for all surviving patients. Results  A total of 106 patients with myasthenia gravis were followed up after thymectomy for a median time of 8 years (range, 1–27 years). Eight patients died during this period. The perioperative mortality rate was 0%, and the morbidity rate was 19.8%. The patients with thymoma and a high preoperative Osserman score had a significantly shorter survival. With minimally invasive procedures, the hospital stay was significantly shorter, and the rate for improvement of myasthenia gravis-associated symptoms was significantly higher. The rate of perioperative complications and myasthenia-related complications during the follow-up period showed no significant differences. Conclusions  Transsternal and minimally invasive thymectomy contribute to an improvement in myasthenia gravis symptoms for all subgroups. Surgery can be performed with low individual risks. In our trial, minimally invasive surgery was found to be superior in terms of improvement in myasthenia gravis-associated symptoms. Additionally, the hospital stay was shorter, and the patients felt less disturbed by direct effects of the operation. Therefore, minimally invasive thymectomy can be regarded as the treatment of choice for patients undergoing surgery for myasthenia gravis.     

Autoimmune myasthenia gravis: Recommendations for treatment and immunologic modulation

Opinion statement Treatment for myasthenia gravis should be individualized to each patient based on the clinical characteristics of myasthenia including the distribution, duration, and severity of weakness and resulting functional impairment; the risks for treatment complications related to age, gender, and medical comorbidities; and the presence of thymoma. Acetylcholinesterase inhibitors provide temporary, symptomatic treatment for all forms of myasthenia gravis. Immune modulators address the underlying autoimmune process in myasthenia gravis, but are associated with potential complications and side effects. Most patients with generalized myasthenia who have significant weakness beyond the ocular muscles and who remain symptomatic, despite treatment with cholinesterase inhibitors, are candidates for immune modulation. Although corticosteroids are effective for long-term immune modulation in myasthenia gravis, several more contemporary immunomodulators including azathioprine, cyclosporine, and mycophenolate mofetil have shown efficacy in myasthenia gravis and are used increasingly as first-line treatments and as steroid-sparing agents. Plasma exchange is used to achieve rapid improvement in patients with myasthenic crisis or exacerbation, to improve strength before a surgical procedure or thymectomy, and to minimize steroid-induced exacerbation in patients with oropharyngeal or respiratory muscle weakness. Intravenous immunoglobulin represents an alternative to plasma exchange in patients requiring relatively rapid short-term improvement in the setting of poor venous access. Because of a lack of controlled trials, the role of thymectomy in nonthymomatous myasthenia gravis is unclear, although evidence suggests that thymectomy increases the probability for myasthenic remission or improvement.