Importance of thymectomy and prognostic factors in the complex treatment of myasthenia gravis

Abstract

BACKGROUND: Thymectomy is indicated in patients with seropositive myasthenia gravis (SPMG) in patients under the age of 50 and in patient with myasthenia gravis (MG) associated with thymoma. METHODS: 345 patients with MG who underwent an extended thymectomy from April 1990 to December 2010. Patients were separated into the 4 groups: group with a complete stable remission, pharmacological remission group, group of patients with signifi cant improvement and the group with mild improvement of symptoms. RESULTS: In our study, we observed 345 patients with MG and thymectomy. 137 patients (39.71 %) attained the complete stable remission (CSR) and 92 patients (26.67 %) the pharmacological remission (PR). The signifi cant improvement of MG symptomatology was achieved in 95 patients (27.54 %). The rest of 21 patients from total 345 (6.08 %) have reached only a mild improvement. Patients after thymectomy with CSR were in the clinical stage I and IIA, in accordance to the modifi ed Osserman classifi cation and most benefi ted from the thymectomy. CONCLUSIONS: The extended thymectomy combined with immunotherapy is the preferred treatment with an expected satisfactory long-term remission rate. Despite the recent improvements in MG medical therapy, thymectomy plays an important role in the otherwise complex treatment of the disease. Because of early diagnosis with thymectomy performed without a delay, patients can achieve signifi cantly more often favorable outcomes and even stable remissions (Tab. 4, Fig. 7, Ref. 17).

Comparison of Short-Term Post-Thymectomy Outcomes by Time-Weighted Dosages of Drug Requirements between Thymoma and Non-Thymoma Myasthenia Gravis Patients

“…This is because thymectomy and long-term and proper-dose immunosuppressive treatment will bring about desirable neurological outcomes [ 12 , 13 , 15 ]. Recently published studies, including a few systematic reviews and meta-analyses evaluating post-thymectomy outcomes, also supported early thymectomy in non-ThMG patients, because thymectomy resulted in the decreased requirement of MG treatment medicines, the improvement of MG clinical status as evaluated by MG-PIS, or even the complete recovery of MG [ 6 , 8 , 9 , 10 , 13 , 15 , 16 , 17 , 18 , 22 ]. Another study advised that extensive transsternal thymectomy should be carried out in generalized, non-Th MG patients aged 18–65 years with a positive AChR Ab test [ 23 ], since the delayed removal of an MG patient’s thymus could cause progressive immunological degradation or irreversible damage of the post-synaptic NMJ receptors.…”

“…Moreover, it has been known that the thymus of MG patients acts as the primary source of auto-antibody production regardless of thymic histopathology, i.e., either thymoma (Th) or non-thymoma (non-Th). Therefore, early thymectomy is advocated, although obvious clinical benefits may require several years after thymectomy [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Additionally, a number of studies have suggested that early thymectomy was superior to conservative treatment in terms of MG clinical remission, regardless of the thymic tissue histopathology [ 7 , 8 , 9 , 10 , 15 , 16 , 17 ].…”

“…Therefore, early thymectomy is advocated, although obvious clinical benefits may require several years after thymectomy [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Additionally, a number of studies have suggested that early thymectomy was superior to conservative treatment in terms of MG clinical remission, regardless of the thymic tissue histopathology [ 7 , 8 , 9 , 10 , 15 , 16 , 17 ]. Currently, the assessment of post-thymectomy outcomes as recommended by the Myasthenia Gravis Foundation of America Post-Intervention Status (MGFA-PIS) requires a neuromuscular specialist, and the evaluation is based only on the groups of drugs, i.e., symptomatic drugs, immunosuppressants or the combination of both, prescribed which were able to minimize or get rid of MG symptoms or signs for at least one year.…”

The comparison of modified minimally invasive and open surgical approaches in the treatment of epithelial thymic tumours

“…The modifi ed maximal minimally invasive thymectomy is a surgical technique that provides the highest level of resection extent of thymic tissue as required by Jaretzki (31). This property is especially important in patients with MGAT (28). All the patients were checked and assessed for symptoms of MG and blood autoantibodies at the Centre of Neuromuscular Diseases which is a centralized and one-of-a-kind facility in Slovakia.…”

“…With the advent of minimally invasive and robotic techniques, these advances were introduced also into thoracic surgery and surgical treatment of thymic pathology (20)(21)(22)(23)(24). In this light, the comparison of these novel techniques with standard care represented by longitudinal sternotomy became the aim of many studies (25)(26)(27)(28). In the Department of Thoracic Surgery in Bratislava we perform a combined mini-invasive method of maximal minimally invasive thymectomy (MMIT) in patients with thymomas regardless of myasthenia gravis involvement (29,30).…”