Decade-long experience with surgical therapy of myasthenia gravis: early complications of 324 transsternal thymectomies.

BACKGROUND: We studied the incidences and evaluated the management of early postoperative complications after thymectomy for myasthenia gravis. METHODS: During the period between 1987 and 1996, 324 thymectomies were performed through median sternotomy access under general anesthesia. Postoperative management was administered according to a standardized protocol of anticholinesterase medication, which was withdrawn for the 48 hours of obligatory postoperative mechanical ventilation. The mean age of patients was 34 years (range, 8 to 71 years). RESULTS: One hundred forty-nine patients made an uneventful recovery; 104 patients had only minor complications, whereas 71 patients had major complications. The mortality rate was 0.6% (2 patients). The major surgical complications were recorded as sternal bleeding (1 patient) and sternal disruption (1 patient). The major general complications were recorded as tracheal stenosis (1 patient), pneumonia (3 patients), heart failure (1 patient), gastric hemorrhage (1 patient), and respiratory insufficiency (71 patients). Forty-six reintubations were performed on 40 patients and 19 tracheostomies (6%) were performed postoperatively. CONCLUSIONS: The excessive incidence of respiratory insufficiency and airway-associated morbidity was potentially related, at least partially, to prolonged mechanical ventilation and withdrawal of anticholinesterase medication. Earlier weaning of patients with revision of 48-hour withdrawal of anticholinesterase medication is necessary.

Dominantly inherited familial myasthenia gravis as a separate genetic entity without involvement of defined candidate gene loci.

Myasthenia gravis (MG) is a sporadic autoimmune disorder affecting neuromuscular transmission. Very rarely autoimmune myasthenia gravis may be inherited within a family. We present here the genetic analysis of a Hungarian family where nine members from two generations are affected by myasthenia gravis. Genetic characterisation of this unique Hungarian family using linkage analysis and mutation screening excludes the involvement of defined candidate gene loci. These findings point to familial MG as a separate genetic entity. Identification of the underlying genetic defect in this family may greatly enhance our understanding of the pathogenesis of myasthenia gravis.

Myasthenia gravis: effect of thymectomy in 425 patients. A 15-year experience.

We report 425 myasthenic patients who underwent thymectomy during the last 15 years. The authors analyse the results of thymectomy in separate groups, including thymomas (12.7%), childhood myasthenia (9.4%) and combined cases (12.4%). They evaluate the results according to the Disability Status Scale based on a points system. Three series were evaluated: patients operated upon between 1972-1977, 1977-1982 and 1982-1987. Although the results in all three series were good, there has been steady improvement over the years. Childhood myasthenia gravis gave the best results but thymectomy was beneficial in the combined (immunological) group, in long-lasting myasthenia and in thymomas. Factors influencing the results of thymectomy were patients' age, time interval between onset of disease and thymectomy, resistence to therapy and thymic tumour. Thymic activity as reflected in germinal centres can also influence the results: the more active the thymus, the better the results.

Altered polyamine levels in skeletal muscle of patients with myasthenia gravis.

Forty patients with myasthenia gravis were tested for polyamine content of the musculus sternothyreoideus removed during thymectomy. Cases with slight muscle alteration were found to show elevated values for all the three polyamines (putrescine, spermidine and spermine) examined with an increased spermidine/spermine ratio. In severe muscular atrophy, however, the high spermidine and spermine levels were accompanied by unchanged putrescine content and spermidine/spermine ratio. Denervational changes in polyamine levels parallel to the degree of muscular damage are useful indicators of the actual grade of muscle atrophy associated with myasthenia gravis. In histologically intact samples, without apparent signs of muscular atrophy the spermidine level and spermidine/spermine ratio were increased in comparison to the control. In addition to being very early signs of denervation, these higher values are possibly the biochemical expression of some adaptive, compensatory hyperfunction of the muscle fibers.

Myasthenia gravis: demonstration of membrane attack complex in muscle end-plates.

The membrane attack complex (MAC) assembles from C5b-9 complement components and has neoantigenic properties. Antihuman-MAC rabbit immunserum was applied in order to localize the MAC in myasthenic muscles. Using the indirect immunoperoxidase method MAC was demonstrated at the motor end-plates in eleven myasthenic patients who underwent thymectomy. This result provides direct evidence of antibody-dependent complement-mediated injury of acetylcholine receptors in myasthenia gravis.

[Myasthenia gravis: results of thymectomy in 550 patients]. / Myasthenia gravis: thymectomia eredménye 550 betegen.

Report is giving on 550 myasthenic patients who underwent thymectomy during the last 18 years. Results of thymectomy are analysed in separate groups and according to different aspects, including thymic tumours (13.63%), operations in childhood (9.64%), and combined cases (11.1%). The results are evaluated according to Disability Status Scale based on a point-system. Successive improvement was observed in the three series concerning the results of operation. Childhood myasthenia gravis gave the best results but thymectomy was beneficial in the combined group, in long-lasting myasthenia and in tumourous cases, too. There are quite a few factors influencing the results, such as the interval between the disease onset and thymectomy, the patients' age, thymoma, crisis-danger and the activity of the thymus gland reflecting in the number of the germinative centres. The more active the thymus, the better the results.

[Tumor-associated myasthenia gravis and myasthenia syndrome]. / Tumorhoz társult myasthenia gravis és myasthenia syndroma.

Out of 700 patients operated on account of myasthenia gravis, 144 cases with tumours (20.57%) were evaluated. Classification took place in five groups: 1. Thymoma and myasthenia gravis; 2. Thymic cysts and myasthenia gravis; 3. Thymoma and latent myasthenia gravis; 4. Paraneoplastic myasthenia-syndrome; 5. Thymoma, myasthenia gravis and myasthenia-syndrome. Up-to-date classification of thymomas is: epithelioma with minimal, marked or overwhelming lymphatic reaction. Dark-cell and light-cell epitheliomas equally associate with myasthenia. Concerning prognosis, location of the tumour to thymic capsula, surrounding, perithymic tissue is more important than the histologic structure of the tumour. Previous examination in the case of mediastinal tumour can reveal latent, mild myasthenia which was not known till that time. Term of postthymectomic myasthenia can be excluded on the basis of these examinations. Heterogeneity is considerable among myasthenia-syndromes concerning both histopathologic and clinical features. There is a double indication of operation in the case of myasthenia with tumour: the tumour and the disease. Good results can be achieved in myasthenia gravis associated with tumour by means of total operation, post-operative radiation and by other up-to-date therapeutical procedures. The results are hardly beyond those of non-tumours myasthenia gravis.