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Thoracoscopic thymectomy is feasible in adolescents with myasthenia gravis. It allows complete resection of the gland with less morbidity, shorter ICU and hospital stay and far superior cosmetic result as compared to trans-sternal thymectomy. Our experience with this procedure in 9 adolescents with myasthenia gravis is presented along with review of the relevant literature.
Anaphylactic shock was induced in adult guinea pigs eight months after operative thymectomy. It was established that thymectomy caused depletion of lymphoid tissue with atrophy of lymphyc follicles and disappearence of germinative centers in the spleen, mesenterial lymph gland and intestinal lymph tissue. There was no anaphyactic shock in 81.2% of the thymectomized animals as a result of the inhibited immunoallergic reactivity, but dystrophic and inflammatory changes in their parenchymatous organs were more frequent and graver in comparison with the nonthymectomized animals.
BACKGROUND: Anesthesia without muscle relaxants has been reported to be effective for early extubation after thymectomy, but postoperative respiratory status of the patients has not been studied intensively. METHODS: Fifty-two consecutive patients undergoing thymectomies for myasthenia gravis (MG) were evaluated. RESULTS: Forty-two (81%) of the 52 patients were extubated in the operating room, and 49 (94%) patients were extubated within 24 hours. However, 6 (12%) patients required subsequent reintubation for respiratory support. There was a sudden increase in the respiratory rate (RR) and PaCO(2). The mean value of the increase in PaCO(2) at the time of reintubation was 23 mmHg (12-58 mmHg). The mean value of the increase in RR above the preoperative level at the time of reintubation was 16/min (7-30/min). In univariate analysis, vital capacity (VC), %VC, the preoperative pyridostigmine dose and the duration of surgery correlated with reintubation, but with multivariate analyses, the pyridostigmine dose was the only significant factor related to reintubation. CONCLUSION: The patients who received at least or more than 240 mg of pyridostigmine should be monitored carefully after tracheal extubation.
Ultrastructural and quantitative immunocytochemical studies of rat pancreata were carried out 1 month after adult thymectomy. The proportions of insulin-, glucagon-, and somatostatin-immunoreactive cells in the pancreas were estimated on paraffin sections using the unlabelled peroxidase-antiperoxidase method. Relative islet volume, islet size and number were determined on hematoxylin and eosin stained sections. A moderate increase of the islet volume on account of size was found in the pancreas of the thymectomized rats. The proportion of insulin-immunoreactive cells was also elevated. Ultrastructural studies showed a rich supply of secretory granules in most beta-cells. Mixed beta-endocrine-acinar cells were often observed. Mitotic figures were found in single beta-cells. The blood glucose level was in the normal range. The findings suggest a moderate stimulation of beta-cell secretory activity after thymectomy which is not associated with elevated blood glucose levels.
The first patient was a 37-year-old man with an invasive and lymphoid cell dominant thymoma (stage III). He underwent extended total thymectomy and partial resection of the upper lobe of the left lung. Four years after the operation, he had ptosis and diplopia and was diagnosed as having myasthenia gravis (positive Tensilon test and raised antiacetylcholine receptor antibody titer). His symptoms improved with the steroid therapy. The second patient was a 37-year-old woman with an invasive and mixed type thymoma (stage III). Extended total thymectomy with combined resection of the mediastinal pleura and right phrenic nerve was performed, but the tumor recurred in the right thorax 2 years postoperatively. Subtotal resection of the parietal pleura and recurrent tumors was performed by right thoracotomy, and steroid therapy was given. She developed malaise, ptosis and diplopia three months later, and was diagnosed as having myasthenia gravis. Her symptoms disappeared after the steroid therapy was stopped. A review of the Japanese literature is presented and problems regarding the pathogenesis of this disease are discussed.
The authors describe a case of systemic lupus erythematosus in a 33-year-old female patient who developed the disease 12 years after thymectomy on account of myasthenia gravis. The activity of systemic lupus erythematosus was controlled by pulsed treatment with methyl prednisolone followed by long-term oral glucocorticoid and immunosuppressive therapy. The authors discuss the risk of systemic lupus erythematosus after thymectomy on account of myasthenia gravis with regard to the HLA haplotype.
Forty-five patients with myasthenia gravis (MG) were subjected to thymectomy by the median sternotomy technique and were followed up for 4,380 patient months. No operative deaths occurred and 93.3% of the patients benefited from surgery with 28.8% achieving remission. Forty patients (88.5%) showed improvement within one month, and 73% of those who achieved remission did so in the first 2 years. Outcome was not affected by thymic pathology except in one patient who had a thymoma removed. These results confirm the value of thymectomy in the management of MG patients with generalised disease and the efficacy of the simple median sternotomy procedure.
OBJECTIVE: To determine predictability factors, clinical features and outcome in the patients after transsternal radical thymectomy (TRT) for Myasthenia Gravis (MG). METHOD: A 14-year retrospective review (1990-2004) and analysis of medical data on 32 patients with MG who underwent TRT. Two patients were lost to follow-up. Preoperative medication included anticholinesterase drugs and steroids. Plasmaphereses were used in 2 cases before operation. The modified Osserman clinical classification (Table 1) was used to define disease severity. The status of the patients was evaluated as follows: A (remission), B (improvement), C (no change), D (deterioration), E (death due to myasthenia gravis). Using univariate analysis, sex, age, onset, Osserman class and pathology correlated with outcome and statistical significance is defined as P < 0.05. RESULTS: Among the 30 patients in the present study with MG who underwent TRT women comprised 70% (21 of 30 patients), and mean age was 42.87 +/- 12.16 year (19-65 years). The preoperative duration of the disease ranged from 0.5 to 120 months (mean = 25.72 +/- 30.68 months). Clinical statuses of patients as assessed on initial evaluation were 13 patients (43.3%) were in class IIA, 6 (20%) in class IIB, and 11 (36.7%) in class III. (Table 2) The histology of thymus glands consisted of hyperplasia in 22 patients, normal in 2, atrophic thymus in 3, thymomas in 3, (2 were malignant thymomas). Hospital mortality was 0, but 9-month mortality was 3.33% (1 of 30 patients). The mean follow-up period was 41.80 +/- 53.89 months. Complete remission (A) was achieved in 40% of patients (12 of 30), and marked improvement (B) of MG in 40% (12 of 30), for a total benefit rate of 80%. 6.7% (2 of 30) were unchanged (C), 10% (3 of 30) were worse (D) and 3.3% died because of MG (E). Using univariate analysis on sex, clinical status by Osseman classification, and histopathology correlated significantly with outcome (P < 0. 05); 95.2% of women (20 of 21) benefited from the procedure, versus 44.4% of men (4 of 9). 100% (19 of 19) of patients in class IIA and IIB benefited from the procedure, versus 45.5% (4 of 9) of patients in class III. All patients with thymoma presented a less favorable outcome (deteriorated in 2, and died in 1) versus 11.1% (3 of 24) of patients without thymomas were deteriorated. CONCLUSION: The remission and improvement in 80% of patients suggested that adequate thymic tissue were removed with radical thymectomy. Female, absence of thymoma, thymic hyperplasia, patients in class IIA, and IIB (non-respiratory involvement) are favorable predictability prognostic factors.
A retrospective matched-pair comparison was undertaken to evaluate the surgical and neurological outcomes after open and VATS thymectomy for patients with myasthenia gravis (MG) and thymoma. Ten women and seven men aged 14-77 years were operated upon in St. Petersburg Center of intensive pulmanology and thoracic surgery during the years 1995-2002. Results of two groups were compared: 1 - operated by VATS (9 patients) and 2 - operated via sterno- or thoracotomy (8 patients). The first step evaluated the distribution of age, gender, myasthenia severity, size, type of thymoma and Masaoka's stage. No difference between the groups was found. At the same time, the length of chest tube, blood loss, severity of postoperative pains were significantly lower in the first group as compared with the second one: 1.3+/-0.9 vs 6.2+/-4.5 days; 82.5+/-22.7 vs 557.1+/-212 ml; and 1.9+/-0.8 vs 6.1+/-1.2 points respectively. The number of postoperative complications was almost the same. All the patients were followed up during 24-96 months. There were no thymoma recurrences in the both groups. No statistical differences were found in MG course between the groups. A conclusion is made that VATS removing of noninvasive thymoma is technically feasible and safe for the patients. VATS thymectomy can provide the same results in MG treatment as the open approaches.
The effect of thymectomy on zoxazolamine paralysis and metabolism was investigated in young female untreated and PCN- or ACTH-pretreated rats. Thymectomy performed at least 24 hr before injection of zoxazolamine significantly prolonges paralysis time. Pretreatment with PCN (an inducer of hepatic microsomal enzymes) or ACTH (known to alter protein binding and excretion of zoxazolamine) shortened paralysis in thymectomized animals; but only in comparison to thymus ablated controls. The surgical intervention seemed to decrease the metabolism of zoxazolamine in the 9,000g supernatant fraction of the liver.
OBJECTIVE: To investigate the prognostic factors of myasthenic crisis after extended thymectomy in patients with generalized myasthenia gravis (MG). METHODS: Extended thymectomy was performed on 176 patients with generalized MG, 74 males and 102 females, aged 4 - 67, of which 36 experienced postoperative myasthenic crisis and required prolonged mechanical ventilation. The relations among the age, sex, preoperative course of disease, pathologic type of thymus, Osserman classification, history of infection during 1 month preoperatively, history of myasthenic crisis 1 month preoperatively, thymoma, preoperative daily dose of pyridostigmine, preoperative steroid use, operation time, intra-operative blood loss, and intra-operative pleura injury and postoperative myasthenia crisis were analyzed. RESULTS: Univariate analysis showed that bulbar symptoms (OR = 8.494, P = 0.001), history of myasthenic crisis 1 month preoperatively (OR = 5.667, P = 0.000), thymoma (OR = 2.147, P = 0.047), Osserman types III and IV (OR = 0.459, P = 0.000), history of infection during 1 month preoperatively (OR = 3.30, P = 0.038), large pre-operative dose of pyridostigmine (OR = 1.019, P = 0.001), long operation time (OR = 1.012, P = 0.034), and more blood loss (186 ml +/- 163 ml) (OR = 1.004, P = 0.012), were all prognostic factors or postoperative myasthenic crisis. However, multivariate logistic regression analysis revealed that preoperative bulbar symptoms (OR = 7.709, P = 0.003), history of infection during 1 month preoperatively (OR = 4.582, P = 0.037), history of myasthenic crisis 1 month preoperatively (OR = 4.526, P = 0.001, large pre-operative dose of pyridostigmine (OR = 1.016, P = 0.001) were prognostic factors of postoperative myasthenic crisis. CONCLUSION: Preoperative bulbar symptoms, history of preoperative myasthenic crisis, history of preoperative infection, and large preoperative dose of, pyridostigmine are all independent influencing factors of postoperative myasthenic crisis. Ample preoperative care may prevent postoperative myasthenic crisis in the patients with such factors.
The time course of structural and functional changes in the parotid and submaxillary salivary glands after neonatal thymectomy was considered. A combination of various methods including histological, histochemical, cytophotometric ones and transmission electron microscopy, was employed. They showed that neonatal thymectomy resulted in an increase in secretory activity of the salivary glands and was followed by hemolymphodynamic disorders and lymphoplasmocytic infiltration.
The dynamics of morphological, enzymatic and immunologic salivary glands indices in pubertal rates was investigated after thymectomy. The data obtained analysis demonstrated the functional salivary glands reconstruction, having immunologic and secretory characteristics: stimulation of the humoral and cellular immunity factors; reduction of the albuminous and rise of the mucous salivary glands component represented the remote effect of thymectomy /3 months]. Activation of the salivary glands immune characteristics may be explained by their belonging to the thymic-peripharyngeal complex.
Mammary tumours which developed in factorless C3Hf mice when transplanted to MTV-S+ and MTV-S- recipients were found to grow at the same rate' early thymectomy failed to influence their growth. The observed accelerated growth of mammary tumour transplants from C3H/He mice to MTV-S+ recipients, as compared to the MTV-S- ones, and inhibition of the tumour growth after early thymectomy seemed to be connected with the peculiarities of the immunological reaction to the virus-induced antigens.
Between 1986 and 1989 27 patients with myasthenia gravis underwent radical thymectomy: 24 patients without and two patients with thymoma through a trans-sternal incision, another with thymomatous myasthenia through a left-sided thoracotomy. The patients were staged according to the modified Ossermann classification. The results were evaluated prospectively according to the Disability Status Scale of Oosterhuis. During a mean follow up of 22.4 months, 21 patients (77%) benefited from the operation with complete remission achieved in 9 (33%) and significant improvement noted in 12 (44%). There were no operative deaths and no hospital morbidity. The mean operation time was 88 minutes, the mean postoperative hospital stay 10.5 days. These results support the recommendation for radical trans-sternal thymectomy in the treatment of patients with myasthenia gravis as a safe procedure.
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.
An experimental model was devised in which an AKR lymphoma is conditioned to grow in BALB mice leading to reproducible tumor incidence which makes tumor-bearing (progressor) and tumor-rejecting (regressor) animals simultaneously available. The object of this paper was to determine the effect of neonatal thymectomy (xT) on allogeneic tumor incidence and on anti-tumor cytophilic activity. The latter was determined by the adherence of lymphoma cells to guinea pig peritoneal macrophages previously incubated with preheated mouse serum. The results obtained, in 2-3 month old animals, show no difference in lethal tumor incidence between xT and intact mice, 36% (14/39) vs. 39% (14/36). Neither did xT alter the significant increase in cytophilic antibodies detected in regressor serum, 115 +/- 15 (S.E.) vs. 106+/- 22 0/00 macrophages bearing tumor cells as compared to control values in either xT or normal serum, 53 +/- 3 vs 52 +/- 3. This background cytophilic activity was not significantly altered in progressor serum of either xT or intact mice, 36 +/- 5 vs 65 +/- 6. The specificity of the antitumor cytophilic antibodies was determined by the negative results obtained when a different tumor was used as target cell. It can be concluded that ant-tumor cytophilic antibodies are detectable in regressor but not in progressor serum. Thymectomy in this model does not alter either in vivo tumor incidence or humoral cytophilic activity. Since no thymic remnants were encountered at autopsy, it is postulated that AKR lymphoma cells, which proved to be neoplastic T cells, are capable of rendering T-immunocompetent a thymectomized allogeneic BALB host.
Review of our results with thymectomy for myasthenia gravis supports the role of early surgery for this debilitating and often lethal disease. The data presented here confirm the fact that thymectomy has rare complications and low operative mortality. Approximately 80 percent of patients with myasthenia gravis can expect clinical improvement with surgery, which also offers a chance for complete remission.