Thymectomy For Myasthenia Gravis Research Articles

Physiological and pathological roles of the thymus and value of thymectomy in myasthenia gravis: a narrative review.

Myasthenia gravis (MG) is a well-elucidated autoimmune disorder affecting the neuromuscular junction. Given the relationship between MG and thymic pathologies, with T cell and antibody-mediated pathogenesis, surgical (i.e., thymectomy) and non-surgical approaches remain a mainstay of management of the disease. This review seeks to outline the involvement of the thymus in the development of lymphocytes leading to MG. Different databases were searched exploring the role of thymectomy in treatment and outcomes in various MG patient subpopulations, including in ocular versus generalized disease, different age groups, and antibody status. Overall, the findings of multiple studies and reviews provide evidence to support the efficacy and long-term success of thymectomy in the management of MG; outcomes have included remission status, symptom severity, and need for adjunctive therapy. However, the heterogeneity in the MG population suggests that there are multiple factors that may confound the results of thymectomy and still need further examination. Separately, other autoimmune diseases develop following thymectomy, and further research is required to elucidate this susceptibility. Finally, our review will discuss the different surgical approaches for thymectomy, including their advantages, limitations, and perioperative complications. Overall, in light of the known pathogenesis and association of the thymus with MG, thymectomy remains an extremely effective approach for long-term management and improved clinical outcomes.

Results Of Minimally Invasive Vats Thymectomy In Miastenia Gravis Patients Compared With More Invasive Approaches - 10-Year Experience In A Single Center.

Myasthenia gravis (MG) is an autoimmune, neurologic disease that causes a wide range of symptoms. While the transsternal, transcervical and thoracotomy approaches are accepted as effective, there is still debate regarding the VATS approach. We analyzed our center's surgical experience with thymectomy for myasthenia gravis, comparing the results of patients operated on using VATS and more invasive approaches, over a period of 10 years. A search of the department's surgical database for myasthenia gravis cases between January 2010 and January 2021, revealed a total of 40 cases. Twenty-four patients were included in the final analysis and were distributed into two groups: the VATS procedure group (group A) and the open procedure group (group B). The latter included sternotomy, thoracotomy, transcervical and hemiclamshell approaches. Only radical thymectomies were included. The established outcomes were clinical improvement defined as asymptomatic remission, reduction, or discontinuation of the medication necessary to achieve optimal symptom control. The median follow-up time was 27 months (ranging from 4 to 75 months). Videothoracoscopy radical thymectomy was performed on 12 patients. Complete remission with no medication was achieved in 1 case (8.3%), while 2 patients (16.7%) became asymptomatic with reduced medication. An improvement (reduced symptoms or decreased medication) was observed in 8 cases (66.6%). No change in clinical outcome was noted in 1 patient (8.3%). None of the patients reported worsening symptoms. Open thymectomy was performed on 12 patients. Complete remission with no medication was achieved in 1 case (8.3%), while 2 patients (16.7%) became asymptomatic with reduced medication. An improvement was noted in 6 cases (50%). No change in clinical outcome was observed in 3 patients (25%) whereas 2 of them (16.7%) experienced slightly better symptom control but with a significant increase in medication. One patient (8.3%) described the clinical results as without any significant change. None of the patients reported worsening symptoms. The videotoracoscopic approach in the treatment of myasthenia gravis is non-inferior compared to the open approach and effective in a long-term follow-up, offering all the additional benefits of less invasive surgery.

Are the minimally invasive techniques the new gold standard in thymus surgery for myasthenia gravis? Experience of a reference single-site in VATS thymectomy.

The thymus is the primary lymphoid organ responsible for the maturation and proliferation of T lymphocytes. During the first years of our lives, the activation and inactivation of T lymphocytes occur within the thymus, facilitating the correct maturation of central immunity. Alterations in the positive and negative selection of T lymphocytes have been studied as the possible origins of autoimmune diseases, with Myasthenia Gravis (MG) being the most representative example. Structural alterations in the thymus appear to be involved in the initial autoimmune response observed in MG, leading to the consideration of thymectomy as part of the treatment for the disease. However, the role of thymectomy in MG has been a subject of controversy for many years. Several publications raised doubts about the lack of evidence justifying thymectomy's role in MG until 2016 when a randomized study comparing thymectomy via sternotomy plus prednisone versus prednisone alone was published in the New England Journal of Medicine (NEJM). The results clearly favored the group of patients who underwent surgery, showing improvements in symptoms, reduced corticosteroid requirements, and fewer recurrences over 3 years of follow-up. In recent years, the emergence of less invasive surgical techniques has made video-assisted or robotic-assisted thoracoscopic (VATS/RATS) thymectomy more common, replacing the traditional sternotomy approach. Despite the increasing use of VATS, it has not been validated as a technique with lower morbidity compared to sternotomy in the treatment of MG. The results of the 2016 trial highlighted the benefits of thymectomy, but all the patients underwent surgery via sternotomy. Our hypothesis is that VATS thymectomy is a technique with lower morbidity, reduced postoperative pain, and shorter postoperative hospital stays than sternotomy. Additionally, VATS offers better clinical improvement in patients with MG. The primary objective of this study is to validate the VATS technique as the preferred approach for thymectomy. Furthermore, we aim to analyze the impact of VATS thymectomy on symptoms and corticosteroid dosage in patients with MG, identifying factors that may predict a better response to surgery.

Association between systemic lupus erythematosus and myasthenia gravis: A population-based National Study

BackgroundSystemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune diseases. Previous case reports and case series suggest an association may exist between these diseases, as well as an increased risk of SLE after thymectomy for MG. We undertook this study to determine whether SLE and MG were associated in large cohorts. MethodsWe searched the IBM Watson Health Explorys platform and the Department of Veterans Affairs Million Veteran Program (MVP) database for diagnoses of SLE and MG. In addition, we examined subjects enrolled in the Lupus Family Registry and Repository (LFRR) as well as controls for a diagnosis of MG. ResultsAmong 59,780,210 individuals captured in Explorys, there were 25,750 with MG and 65,370 with SLE. 370 subjects had both. Those with MG were >10 times more likely to have SLE than those without MG. Those with both diseases were more likely to be women, African American, and at a younger age than MG subjects without SLE. In addition, the MG patients who underwent thymectomy had an increased risk of SLE compared to MG patients who had not undergone thymectomy (OR 3.11, 95% CI: 2.12 to 4.55). Autoimmune diseases such as pernicious anemia and miscellaneous comorbidities such as chronic kidney disease were significantly more common in MG patients who developed SLE. In the MVP, SLE and MG were also significantly associated. Association of SLE and MG in a large SLE cohort with rigorous SLE classification confirmed the association of SLE with MG at a similar level. ConclusionWhile the number of patients with both MG and SLE is small, SLE and MG are strongly associated together in very large databases and a large SLE cohort.

Attitudes and Beliefs Toward Thymectomy in the Myasthenia Gravis Patient Registry.

To evaluate patient attitudes and beliefs toward thymectomy for myasthenia gravis (MG). The Myasthenia Gravis Foundation of America administered a questionnaire to the MG Patient Registry, an ongoing longitudinal survey of adult MG patients. Questions assessed reasons for or against thymectomy and how hypothetical scenarios would have affected their decision. Of 621 respondents, 190 (31%) reported a history of thymectomy. Of those who underwent thymectomy for nonthymomatous MG, 97 (51.6%) ranked symptom improvement as most important and 100 (53.2%) ranked reducing medication as least important. Among 431 nonthymectomy patients, the most frequent reason for not undergoing thymectomy was that their doctor did not discuss it (152 of 431 = 35.2%) and 235 (56.8%) said that they would have considered it more strongly if their doctor spent more time discussing it. Thymectomies are motivated more by symptoms than by medication, and a lack of neurologist discussion is the most common barrier to thymectomy.

The short and long-term effects of open vs minimally invasive thymectomy in myasthenia gravis patients: a systematic review and meta-analysis.

Thymectomy has been utilized as a treatment for Myasthenia Gravis (MG) for many decades, with both open and minimally invasive surgical (MIS) techniques currently used. Although MIS has shown improved short-term results, long-term effects remain uncertain. This systematic review and meta-analysis aim to compare the post-operative and long-term outcomes of MIS versus open thymectomy in MG patients. MEDLINE, EMBASE and CENTRAL databases were searched from inception till January 2022 for keywords related to MG and open or MIS thymectomy. Primary outcome was complete stable remission (CSR), and secondary outcomes were clinical improvement, complications, length of stay, operation time, and blood loss. Grading of recommendations, assessment, development, and evaluation was used to assess the certainty of evidence. 26 studies with 3588 patients were included in the analysis. At 1, 3 and 5years, there was no statistical difference noted in CSR between open versus MIS thymectomy. However, CSR was improved at 1year for MIS thymectomy in non-thymomatous MG (P = 0.03). There was no significant difference in rates of partial clinical improvement between techniques at 1-year. Although analyses on length of hospital stay and blood loss showed improvement following MIS thymectomy, operative time was shorter for open thymectomy. This is the first systematic review and meta-analysis assessing long-term effects of MIS versus open thymectomy in MG patients. Given the lack of significant differences noted, either MIS or open thymectomy can be performed, based on surgeon preference. Further high-level, long-term research should be conducted to determine the benefit of each technique.

Discussion

Discussion

Thymectomy in myasthenia gravis: "The real world" experience beyond studies.

Thymectomy in myasthenia gravis: "The real world" experience beyond studies.

Complete atrioventricular block under epidural ropivacaine infusion in a patient with first-degree atrioventricular block and myasthenia gravis: a case report

BackgroundFirst-degree atrioventricular block (AVB) may lead to complete AVB. Herein, we present a case of a complete AVB under thoracic epidural catheter infusion of ropivacaine with fentanyl in a patient with first-degree AVB and myasthenia gravis.Case presentationA 74-year-old woman with first-degree AVB underwent thymectomy for myasthenia gravis. Continuous thoracic epidural catheter infusion of 0.2% ropivacaine with fentanyl was initiated at 15 min before the end of the surgery. At 9 h postoperatively, the electrocardiogram showed a 10-s-long pause due to complete AVB. Thus, a temporary pacemaker was implanted, and at 19 h postoperatively on postoperative day 1, cardiac pacing was initiated and lasted approximately 30 s. After catheter removal, she had no further episodes of complete AVB.ConclusionFirst-degree AVB may lead to complete AVB under the influence of thoracic epidural infusion of ropivacaine in patients with myasthenia gravis.

Factors predicting surgical outcome of thymectomy in myasthenia gravis

Aim of the study is to evaluate predictors of outcome after thymectomy in the management of non thymomatous myasthenia gravis. One hundred patients who underwent thymectomy for myasthenia gravis in the period between June 2019 and September 2021 in Kasr Alainy hospitals were recruited to this study.
 Preoperative assessment included age, gender, co morbidities, MGFA classification, duration of symptoms from time of diagnosis till surgery, preoperative medication, preoperative plasmapheresis. All patients performed CT chest, electromyography, and acetyl choline receptor antibody titer before and after surgery. Thymectomy was performed either by transsternal or VATS approach with documentation of the extent of resection; primary outcome was assessment of improvement by MGFA classification and need for medication. Secondary outcome was postoperative complications. Complete stable remission was achieved in 5 patients, clinical and pharmacological improvements were achieved in 71 patients, 21 patients didn’t improve and only 3 patients worsen after surgery. Finally, we found that early onset MG, absent preoperative comorbidity, performing extended thymectomy and reduction of postoperative Acetyl choline receptor antibody titer were significant predictors of improvement of MG symptoms after thymectomy.

Comparison of two-lung and one-lung ventilation in bilateral video-assisted thoracoscopic extended thymectomy in myasthenia gravis: a retrospective study.

BackgroundMyasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.MethodsWe retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0–T8) and collected respiratory and hemodynamic variables, including arterial O2 index (PaO2/FiO2).ResultsSpO2 at T1–T3 and T8 was significantly lower in group D than in group S. The FiO2 in group S was lower than that in group D at all time points. The number of PaO2/FiO2 ≤ 300 and PaO2/FiO2 ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D.ConclusionsThis retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.

Thymectomy in Myasthenia Gravis: A Narrative Review.

Myasthenia gravis (MG) is a rare condition caused by autoantibodies against acetylcholine receptors on postsynaptic membrane that leads to weakness of skeletal muscles. About 7 of 10 patients with MG have thymic hyperplasia and about 1 of 10 patients have thymoma. Thymectomy has increasingly been used as a treatment modality for MG. Several observational studies have shown that thymectomy results in improvement in MG and a randomized trial has established that thymectomy leads to a better outcome in non-thymomatous generalized MG. However, thymectomy is yet controversial in some disease subtypes and there are potential concerns regarding the selection of the ideal surgical approach to achieve complete removal of the thymic tissue to achieve stable remission rates. This review highlights the role of thymectomy in non-thymomatous and thymomatous MG, the effectiveness of various thymectomy methods, postoperative myasthenic crisis, and remission after thymectomy.

Robotic thymectomy for myasthenia gravis surgical techniques and outcomes.

Myasthenia gravis (MG) is an autoimmune disorder in which antibodies are produced against post-synaptic acetylcholine receptors, thereby causing impairment of neuromuscular transmission. Diagnosis of MG is confirmed with the AChR antibody test and via an Electromyography. Although medical treatment with acetylcholinesterase inhibitors remains the main treatment of MG, in recent years thymectomy has become an integral part of the treatment algorithm. Numerous factors such as the Patient’s age, presence of AChR antibodies, or MuSK antibody, the severity of disease affect the decision of preforming the thymectomy. Historically thymectomy was preformed via sternotomy associated with significant morbidity. Advancement in the minimally invasive approaches to thymic resection has led to more acceptance of thymectomy in the management of MG. Among these approaches, robotic thymectomy is gaining popularity across the globe due to the unique advantages of the robotic platform like 3D visibility, enhanced dexterity, and wrist like articulating movements of instruments. This has led to less post-operative pain and morbidity; faster recovery and shorter hospital stay. Successful treatment of MG requires a multi-modality approach, which has led to the formation of MG teams in most academic centers, comprising of a specialist neurologist, intensivist, and thoracic surgeon. In this article, we describe the techniques and outcomes of the robotic thymectomy for MG.

Narrative Review of Surgery for Myasthenia Gravis

Myasthenia Gravis (MG) is a rare autoimmune disorder characterized by antibody mediated blockade of neuromuscular transmission. Up until the last decade, evidence suggesting benefit of thymectomy for myasthenia gravis has been based on non-randomized control studies. Our paper serves as an expert narrative review of new literature pertaining to surgical management of myasthenia gravis based on review of articles from PubMed and Cochrane database from date of inception through June 14, 2021. We used the MeSH search terms: “myasthenia gravis”; “thymectomy”; “thymoma”; and “surgery” to identify any new relevant articles for inclusion in our review. The results of these studies are summarized below. We reviewed multiple articles including two randomized control trials. As a result of these studies over the past decade, the American Academy of Neurology’s most recent practice advisory, published online March 25, 2020, gives a level ‘B’ recommendation for thymectomy for MG in patients with acetylcholine receptor antibody-positive generalized MG age 18-65 years old. They additionally noted the need for further discussion surrounding the benefits and risks of surgery and whether minimally invasive approaches to thymectomy would provide the same benefits as the traditional transsternal approach. Evidence recommending thymectomy during pregnancy remains limited due to lack of available data. Emerging evidence suggests that performance of video-assisted or robotic-assisted thymectomy is feasible, but further study is needed due to a lack of randomized control trials.

Surgical Approaches to Thymectomy in Myasthenia Gravis

The relationship of the thymus to myasthenia gravis (MG) has been appreciated since Blalock reported the clinical benefit of thymectomy in myasthenic

Impact of the Surgical Approach to Thymectomy Upon Complete Stable Remission Rates in Myasthenia Gravis: A Meta-analysis.

To determine whether the available operative techniques for thymectomy in myasthenia gravis (MG) confer variable chances for achieving complete stable remission (CSR), we performed a meta-analysis of comparative studies of surgical approaches to thymectomy. Meta-analysis was done of all studies providing comparative data on thymectomy approaches, with CSR reported and minimum 3-year mean follow-up. Twelve cohort studies and 1 randomized clinical trial, containing 1,598 patients, met entry criteria. At 3 years, CSR from MG was similar after video-assisted thoracoscopic (VATS) extended vs both basic (relative risk [RR] 1.00, p = 1.00, 95% confidence interval [CI] 0.39-2.58) and extended (RR 0.96, p = 0.74, 95% CI 0.72-1.27) transsternal approaches. CSR at 3 years was also similar after extended transsternal vs combined transcervical-subxiphoid (RR 1.08, p = 0.62, 95% CI 0.8-1.44) approaches. VATS extended approaches remained statistically equivalent to extended transsternal approaches through 9 years of follow-up (RR 1.51, p = 0.05, 95% CI 0.99-2.30). The only significant difference in CSR rate between a traditional open and a minimally invasive approach was seen at 10 years when the now-abandoned basic (non-sternum-lifting) transcervical approach was compared to the extended transsternal approach (RR 0.4, p = 0.01, 95% CI 0.2-0.8). A significant difference in the rate of CSR among various surgical approaches for thymectomy in MG was identified only at long-term follow-up and only between what might be considered the most aggressive approach (extended transsternal thymectomy) and the least aggressive approach (basic transcervical thymectomy). Extended minimally invasive approaches appear to have CSR rates equivalent to those of extended transsternal approaches and are therefore appropriate in the hands of experienced surgeons.

Rocuronium reversed with sugammadex for thymectomy in myasthenia gravis: A retrospective analysis of complications from Japan.

Postoperative respiratory failure is a serious problem in the anaesthetic management of patients with myasthenia gravis who undergo thymectomy. Although the classical recommendation is to avoid neuromuscular blockers, there is no strong evidence to support it. To evaluate the postoperative outcomes in patients with myasthenia gravis after thymectomy when anaesthetic management included rocuronium reversed with sugammadex. A retrospective cohort study. Nationwide acute in-patient care database. A total of 1143 patients with myasthenia gravis who underwent thymectomy were included. Data were collected from the medical insurance claims data of acute care in-patient hospitals. The postoperative complications when rocuronium reversed with sugammadex was compared against no muscle relaxant use using propensity score matching. The primary outcomes were the rates of in-hospital mortality, plasma exchange following thymectomy and the use of immunoglobulins. The secondary outcomes were the length of stay in the high dependency/ICUs, the total length of hospital stay and the duration and type of respiratory support following thymectomy. There were no significant differences between the propensity score matched groups in terms of plasma exchange [relative risk, 0.96; 95% confidence interval (CI), 0.64 to 1.43] and use of immunoglobulins (relative risk, 1.09; 95% CI, 0.60 to 1.97). The length of hospital stay was significantly shorter in patients in whom rocuronium and sugammadex were used: 29.0 vs. 35.4 days, P = 0.035. Anaesthetic management with rocuronium reversed by sugammadex was not associated with increased risk of respiratory complications. These findings could help in the anaesthetic management of patients with myasthenia gravis.

The role of thymectomy in myasthenia gravis: A programmatic approach to thymectomy and perioperative management of myasthenia gravis

BackgroundMyasthenia gravis is a rare autoimmune disease caused by antibodies that probably originate from the thymus glands. This study examined the epidemiology of patients with MG, who underwent thymectomy over the last three decades. MethodsThe objectives of this observational study were to investigate the clinicopathological features, treatment modalities, and prognostic factors for patients with thymic masses, over three decades at the Royal Hospital, Muscat, Oman. ResultsThere were 100 patients who underwent thymectomy with a mean (SD) age of 32.0 (8.6) years, of which 20% were men and 80% were women. Their follow up period, cardiac and neurology clinics, ranged from 1.5 to 12.0 years with a mean (SD) of 6.0 (3.0) years. Small percentage of MG patients had diabetes and hypertension and 10% of patients have positive family history of MG.Symptoms at the onset of the disease were ophthalmoplegia in 75%, limb weakness in 39%, bulbar symptoms in 57% and respiratory symptoms in 39% of patients. The Osserman grading was Grade I – 5%, Grade IIA – 39%, Grade IIB – 34%, and Grade III – 22%.Post thymectomy, 21% of patients had complete clinical remission, 76% of patients had significant clinical improvement and 3% had no apparent improvement in their clinical status. Histologically, hyperplasia was found in 57% and involuted thymus in 18% of patients. ConclusionThymectomy can reduce patient’s need for medication and reduce the severity of MG regardless of age, sex, severity, or length of sickness, or thymic masses. The early-onset, sever M.G, female, thymic hyperplasia benefit the most. Patients classified as Osserman Class IIA and IIB benefit most from this procedure.

Determinants of Suboptimal Outcome Following Thymectomy in Myasthenia Gravis.

Response to thymectomy in myasthenia gravis (MG) is influenced by various patient-, disease-, and therapy-related factors. Retrospective analysis of 128 patients with MG who underwent maximal thymectomy over 15 years was done to identify the determinants of suboptimal clinical outcome. Among the 128 patients, 62 (48.4%) were females with a mean age of 38.97 (12.29) years. Thymomatous MG occurred in 66 (51.6%). Overall improvement from preoperative status was noted in 88 (68.8%) patients after mean follow-up of 51.68 (33.21) months. The presence of thymoma was the major predictor of suboptimal clinical outcome (P = 0.001), whereas age, gender, preoperative disease severity, and seropositive status did not attain significance. Patients with better outcome had received higher steroid dose preoperatively (P = 0.035). Suboptimal response after thymectomy occurred in one-third of MG patients, more commonly with thymomatous MG. Relationship of preoperative steroid therapy to remission merits evaluation.

Transition of maximum phonation time after extended thymectomy in myasthenia gravis: a case report

Transition of maximum phonation time after extended thymectomy in myasthenia gravis: a case report