The Incidence of Myasthenia Gravis in the Province of Ferrara, Italy, in the Period of 2008-2022: An Update on a 40-Year Observation and the Influence of the COVID-19 Pandemic

Myasthenia gravis (MG) is the most common neuromuscular junction disorder. We evaluated the MG incidence rate in the province of Ferrara, Northern Italy, over two time frames (2008-2018 and 2019-2022, i.e., the COVID-19 pandemic) and considered early-onset (EOMG), late-onset (LOMG), and thymoma- and non-thymoma-associated MG. Moreover, in the second period, we assessed its possible relationship with SARS-CoV-2 infection or COVID-19 vaccination. We used a complete enumeration approach to estimate the MG incidence and its temporal trend. For the period of 2008-18, 106 new cases were identified (mean incidence rate 2.7/100,000 people). The highest rates were observed for the over-70 age group and in rural areas, with 17% of thymoma-associated MG. During the COVID-19 period, 29 new cases were identified (average incidence rate 2.1/100,000 people), showing a marked (though not statistically significant) decrease in the mean annual incidence compared to the previous period. Again, the highest rate was observed for the over-70 age group. The first period was in line with our previous observations for the period between 1985 and 2007, highlighting a rising incidence of LOMG and a marked decrease in EOMG. During the COVID-19 period, incidence rates were lower in the first years whereas, when the pandemic ended, the previous trend was confirmed.

FcRN receptor antagonists in the management of myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disorder characterized by autoantibodies specifically directed against proteins located within the postsynaptic membrane of the neuromuscular junction. These pathogenic autoantibodies can be reduced by therapies such as plasma exchange, IVIG infusions and other immunosuppressive agents. However, there are significant side effects associated with most of these therapies. Since there is a better understanding of the molecular structure and the biological properties of the neonatal Fc receptors (FcRn), it possesses an attractive profile in treating myasthenia gravis. FcRn receptors prevent the catabolism of IgG by impeding their lysosomal degradation and facilitating their extracellular release at physiological pH, consequently extending the IgG half-life. Thus, the catabolism of IgG can be enhanced by blocking the FcRn, leading to outcomes similar to those achieved through plasma exchange with no significant safety concerns. The available studies suggest that FcRn holds promise as a versatile therapeutic intervention, capable of delivering beneficial outcomes in patients with distinct characteristics and varying degrees of MG severity. Efgartigimod is already approved for the treatment of generalized MG, rozanolixizumab is under review by health authorities, and phase 3 trials of nipocalimab and batoclimab are underway. Here, we will review the available data on FcRn therapeutic agents in the management of MG.

The Clinical Outcome in AChR-Positive Generalized Myasthenia Gravis: A Retrospective Observational Study

Background

Myasthenia gravis (MG) is an autoimmune disease affecting the neuromuscular junction, and in over 80% of cases, antibodies are identified against the nicotinic type of acetylcholine receptor (AChR) on the muscle endplate. Despite the availability of various treatment options, patients with MG experience relapses and remission during the course of the disease. Aims and Objective: To understand the clinical profile, predictors of outcomes in acetyl choline receptor (AChR) antibody positive generalized MG.

Methods

This is a retrospective, single-centre, observational study of 108 patients with AChR positive generalized MG. We collected data on clinical and demographical profiles, treatments received, and treatment responses from those who fulfilled inclusion criteria over a mean follow up period of 33.75 ±7.30 months. Clinical outcomes were studied in terms of the type of remission and crisis or disease exacerbations patients had, considering different variables and treatment received.

Results

We found the commonest initial symptoms were ocular or oculo-bulbar, which progressed to generalized MG in the first year of disease onset. 36 (33.3%) patients experienced a crisis requiring mechanical ventilation within a mean period of 9.4 ±4.77 months from the disease onset. Multivariate regression analysis showed late-onset MG (age of onset between 50-70 years) and treatment with rituximab were better correlated with remission, (odd ratio of 4.7; 95 % CI ,1.12 -12.6; P value < 0.05 and odd ratio of 4.56; 95 % CI ,1.2 -10.04; P value < 0.05) respectively. While treatment with Mycofenolate Mofetile (MMF) was associated with a higher number of relapses (odd ratio of 1.8; 95 % CI ,0.08 -0.96; P value < 0.05). Treatment with Rituximab showed a higher rate of remission as compared to treatment refractory (TR) on conventional immunosuppressant therapy (IST). Out of 35(32 %) thymoma patients, 21 patients underwent thymectomy and these patients showed significantly greater rate of remission as compared both thymoma patients who denied thymectomy as a treatment option (N = 10 ;55.60 % vs N = 4; 23.50%).

Conclusion

In this study of AChR antibody positive generalized MG patients, we found that nearly one-third of them experienced myasthenic crisis despite receiving the best medical care. Rituximab appeared to be effective in the treatment of refractory MG and those who failed thymectomy. Thymectomy was associated with better outcomes in patients, both with or without a thymoma.

The role of the gut microbiota and fecal microbiota transplantation in neuroimmune diseases

The gut microbiota plays a key role in the function of the host immune system and neuroimmune diseases. Alterations in the composition of the gut microbiota can lead to pathology and altered formation of microbiota-derived components and metabolites. A series of neuroimmune diseases, such as myasthenia gravis (MG), multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSDs), Guillain-Barré syndrome (GBS), and autoimmune encephalitis (AIE), are associated with changes in the gut microbiota. Microecological therapy by improving the gut microbiota is expected to be an effective measure for treating and preventing some neuroimmune diseases. This article reviews the research progress related to the roles of gut microbiota and fecal microbiota transplantation (FMT) in neuroimmune diseases.

Case report: Persistent hypogammaglobulinemia in thymoma-associated myasthenia gravis: the impact of rituximab or Good's syndrome?

Introduction

Rituximab (RTX) showed good efficacy and safety for patients with myasthenia gravis. However, the percentage of peripheral CD20+ B cell may be absent for years after low dose of RTX treatment. Persistent hypogammaglobulinemia and opportunistic infection may occur in patients under treatment of RTX with thymoma relapse.

Case representation

We report a case of refractory myasthenia gravis. After two doses of 100 mg rituximab, the patient developed transient neutropenia. The peripheral blood CD20+ B cell percentage was 0 more than 3 years. Eighteen months later, the patient's symptoms relapsed with thymoma recurred. She had persistent hypogammaglobulinemia and multiple opportunistic infections.

Conclusion

In MG patient under B cell depletion therapy had thymoma relapse, Good's syndrome may induce prolonged B cell depletion, hypogammaglobulinemia and opportunistic infections.

An asymptomatic giant AB thymoma in a patient with Down syndrome: a case report

Background

Mediastinal mass management may represent a real challenge for all the physicians who deal with it. Mediastinum, in fact, contains different vital structures which are often involved by growing neoplasms with increasing severity. Therefore, up to 60% of the patients with mediastinal mass are symptomatic, according to the structure involved. Different neoplasms may arise essentially from all mediastinal organs, whereas thymic epithelial tumors and lymphomas represent more than 90% of mediastinal tumors.

Case Description

We report the first case described of a giant asymptomatic mediastinal mass in a 43-year-old male affected by Down syndrome (DS), turned out to be a thymoma, treated exclusively and successfully with radical surgery. Despite the absence of any symptoms, the giant thymoma infiltrated the diaphragm, the pericardium, the upper lobe of the left lung together with the left phrenic nerve resulting in the compression of heart and great vessels.

Conclusions

To date, this is the first description of a thymic malignancy in a patient with DS, that usually is characterized by a low-incidence of solid tumor except for germ-cells ones. Surgery has been extremely challenging, due the clinical condition of the patient together with the tumor features; nevertheless, oncological radicality criteria were completely fulfilled. After four years from surgery, the patient is alive and still disease-free, highlighting the importance of radical surgery.

Single-cell transcriptomics and network pharmacology reveal therapeutic targets of Jianpi Yiqi Bugan Yishen decoction in immune cell subsets of children with myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) is an acquired autoimmune disease of the neuromuscular junction. As immunosuppressive agents used to treat MG have a significant impact on the growth and development of children, treatment is extremely challenging. Jianpi Yiqi Bugan Yishen Decoction (JYBYD) has been developed to treat MG and has achieved satisfactory results in clinical practice. This study aimed to explore its action mechanism and evaluate its active ingredients and potential therapeutic targets.

METHODS

Single-cell transcriptome sequencing of peripheral blood immune cells of children with MG was performed to reveal the changes in immune cell profiles before and after JYBYD treatment. Lewis rats were included in the model, with classic MG induced by subcutaneous injection of the immunogen acetylcholine receptor (AChR). Twenty rats were divided into two groups and administered normal saline and JYBYD by gavage daily.

RESULTS

An increase in cell populations characterized by cortactin expression was observed, which has a potential effect on the recovery of lesions at the neuromuscular junction in patients with MG. Based on the differential expression of genes in various immune cells and the predicted targets of traditional Chinese medicine (TCM) compounds, the possible therapeutic targets of JYBYD in different cell subsets were identified, among which STAT1, MCL1, and FOS were the most frequent. Comprehensive network pharmacological analysis suggested quercetin, luteolin, and resveratrol as important active ingredients of JYBYD for the treatment of children with MG. JYBYD could relieve myasthenia symptoms and reduce the AChR-Ab titer in the rat model. Immunohistochemistry results of the muscle showed that JYBYD treatment decreased the expression of STAT1, MCL1, and c-FOS proteins in the muscles of MG rat models.

CONCLUSIONS

The results of this study are of significance for the clinical application of JYBYD and drug development against MG in children.

Assessment of length of stay and cost of minimally invasive versus open thymectomies in patients with myasthenia gravis in Florida

BACKGROUND

Thymectomy has become a standard component in treatment for myasthenia gravis. The best surgical approach is still subject to debate. Minimally invasive surgery may have a lower mortality and morbidity rate, improved cosmetic results, and equivalent efficacy at improving neurologic symptoms to open approaches. We compared the perioperative outcomes and cost between the two techniques.

METHODS

We queried Florida Inpatient Discharge Dataset for patients who underwent thymectomy and had a primary diagnosis of non-thymomatous myasthenia gravis using International Classification of Diseases (ICD)-9 and ICD-10 codes to carry out this retrospective cohort study. The dates ranged between January 1st, 2013, to December 31st, 2018. We compared outcomes of patients who underwent minimally invasive thymectomy versus those who had open thymectomy.

RESULTS

An open approach was used in 108 patients, whereas a minimally invasive approach was used in 40 patients. Minimally invasive surgery group had a shorter length of stay (3.0 vs. 6.0 days, P<0.001) and had a non-significant lower total cost ($18.4K vs. $22.1K, P=0.186). After adjusting for age and Elixhauser score, length of stay for minimally invasive group was 32% (P=0.01) lower compared to the open surgery group.

CONCLUSIONS

Patients who underwent minimally invasive thymectomy for Myasthenia gravis had a significantly shorter length of stay and a lower, although not significant, overall cost.

Taste disorder in a patient with invasive thymoma without myasthenia gravis: a rare case report

Taste disorder has been reported as a non-motor symptom caused by myasthenia gravis (MG)-related autoimmune mechanism. Taste disorder in some cases recovered along with MG treatment, such as thymothymectomy or immunosuppressive treatment. However, symptom of taste disorder in thymoma patients without MG is very rare. Here, we reported a case of invasive thymoma without MG which had concurrent taste disorder. The taste disorder was successfully treated with cyclosporine. A female in her seventies had an anterior mediastinal tumor of 78-mm in diameter and pleural dissemination. She also had taste disorder, limited to sweet taste, and pure red cell aplasia (PRCA). Symptoms and physical findings showed no feature of MG. Pre-operative blood examination revealed no elevation of anti-acetylcholine receptor antibody . Extended total thymothymectomy and resection of all detectable pleural disseminations was performed. Pathological examination showed type B3 thymoma. Clinical stage was Masaoka stage IVa. After operation, there was no improvement in taste disorder and PRCA. Six months after operation, cyclosporine was administered for PRCA. In parallel with gradual improvement of anemia, taste disorder also gradually improved. Three months after the first administration of cyclosporine, taste disorder had completely recovered. This is the first case of taste disorder without any myasthenic status, which recovered with immunosuppressive drug. Our case suggested the potency of immunosuppressive treatment for taste disorder associate with thymoma without MG.

Outcomes of extended surgical resections for locally advanced thymic malignancies: a narrative review

BACKGROUND AND OBJECTIVE

Thymic malignancies represent the most common anterior mediastinal neoplasms, as well as rare and challenging tumors. Surgery is the cornerstone in the treatment of thymic malignancies, although a multidisciplinary approach is mandatory, for both, locally advanced or metastatic disease. In our narrative review, we explored the recent literature to investigate clinical and radiological assessment, multimodality approach and outcomes of locally advanced thymic tumors. More than one-third of patients affected by an anterior mediastinal mass are asymptomatic at diagnosis. In case of locally advanced thymoma, symptoms are related to compression or invasion of adjacent structures, such as the superior vena cava (SVC), innominate veins and pericardium. Paraneoplastic syndromes, such as myasthenia gravis (MG), are related to release of antibodies, hormones and cytokines.

METHODS

Diagnostic methods must be chosen accurately to avoid unnecessary surgical resections, to define the best strategy of care, and to plan the surgical strategy. Therefore, each case must be evaluated in a multidisciplinary context, where surgery plays an essential role.

KEY CONTENT AND FINDINGS

In this narrative review, we describe indications and surgical techniques for the treatment of locally advanced thymoma; focusing on oncological outcomes after different approaches.

CONCLUSIONS

In conclusion, aggressive surgery is always indicated, when possible, and when a complete resection can be planned, yet, the multidisciplinary approach is mandatory, in case of both locally or metastatic advanced disease.

Relationship between anti-acetylcholine receptor antibodies and the development of post-thymectomy myasthenia gravis in patients with thymoma: a single-center experience

Background

Approximately 15-29.6% of patients with thymoma have myasthenia gravis (MG). Some of these patients develop MG after thymectomy despite having no history of MG or related symptoms. Few previous studies have examined the risk factors for the development of post-thymectomy MG in patients with thymoma. Herein, we retrospectively reviewed our institutional experience with patients with thymoma who developed MG after thymectomy.

Methods

Twenty-six patients with thymoma but without MG, who were tested preoperatively for anti-acetylcholine receptor antibody (anti-AChR-Ab) levels, underwent surgical resection at our hospital between 2013 and 2020. Patients with thymic carcinoma were excluded from the study. We evaluated the association of outcomes with preoperative anti-AChR-Ab levels and post-thymectomy MG. We performed a χ² test for bivariate analysis of categorical data. Differences were considered significant at P<0.05.

Results

The characteristics of the 26 patients (median age: 62 years; 8 men, 18 women) were as follows: World Health Organization (WHO) classifications AB (n=8), B1 (n=9), B2 (n=6), B3 (n=1), and others (n=2) and Masaoka stage I (n=12), II (n=9), III (n=3), and IVa (n=2). Among the 26 patients, only five had high (>0.3 nmol/L) preoperative anti-AChR-Ab levels. Post-thymectomy MG occurred in two of the five patients (40%) with high preoperative anti-AChR-Ab levels. A high preoperative serum anti-AChR-Ab titer was significantly associated with post-thymectomy MG (P=0.0267). The anti-AChR-Ab titer was also measured postoperatively in four of the five (80%) patients with high preoperative levels. The anti-AChR-Ab titer decreased in two of these four patients, and neither developed postoperative MG.

Conclusions

Preoperative and postoperative anti-AChR-Ab positivity might be associated with post-thymectomy MG. Therefore, regular measurement of anti-AChR-Ab levels after thymectomy is required.

Influenza vaccination in autoimmune neuromuscular diseases: A survey of current practices and perceptions

INTRODUCTION

Recommendations for receiving the influenza vaccination in patients with autoimmune neuromuscular disorders, such as myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), or Guillain-Barré syndrome (GBS), may vary among neurology practitioners. This survey examined the current practices and perceptions of neurologists regarding the influenza vaccination in these patients.

METHODS

We performed an Internet-based survey among neurologists across the United States through online forums for neurologists.

RESULTS

Across practice settings, 184 neurologists followed 6465 MG, 2313 CIDP, and 1907 GBS patients. Among the respondents, 82.6%, 58.8%, and 42.3% reported that they recommend the influenza vaccine for all patients with MG, CIDP, and GBS, respectively. Respondents practicing for more than 10 y were more conservative in recommending the influenza vaccine for all patients with MG. A history of exacerbation following the influenza vaccine was regarded as the most important factor influencing vaccine recommendation for MG and CIDP.

DISCUSSION

Influenza vaccination recommendation practices varied between surveyed neurologists, despite existing guidelines. Clearer professional society recommendations and education are an unmet need based on this apparent knowledge gap.

Immunopathology of Autoimmune Myasthenia Gravis: Implications for Improved Testing Algorithms and Treatment Strategies

Myasthenia gravis (MG) is a heterogeneous condition, characterized by autoantibodies (Abs) that target functionally important structures within neuromuscular junctions (NMJ), thus affecting nerve-to-muscle transmission. MG patients are more often now subgrouped based on the profile of serum autoantibodies, which segregate with clinical presentation, immunopathology, and their response to therapies. The serological testing plays an essential role in confirming MG diagnosis and guiding disease management, although a small percentage of MG patients remain negative for antibodies. With the advancements in new highly effective pathophysiologically-specific immunotherapeutic options, it has become increasingly important to identify the specific Abs responsible for the pathogenicity in individual MG patients. There are several new assays and protocols being developed for the improved detection of Abs in MG patients. This review focuses on the divergent immunopathological mechanisms in MG, and discusses their relevance to improved diagnostic and treatment. We propose a comprehensive "reflex testing," algorithm for the presence of MG autoantibodies, and foresee that in the near future, the convenience and specificity of novel assays will permit the clinicians to consider them into routine systematic testing, thus stimulating laboratories to make these tests available. Moreover, adopting treatment driven testing algorithms will be crucial to identify subgroups of patients potentially benefiting from novel immunotherapies for MG.

Genomic alterations in thymoma-molecular pathogenesis?

Thymomas and thymic carcinomas (TCs) are neoplasms of thymic epithelial cells. Thymomas exhibit a low mutational burden and a few recurrently mutated genes. The most frequent missense mutation p.(Leu404His) affects the general transcription factor IIi (GTF2I) and is specific for thymic epithelial tumors (TETs). The clinically indolent types A and AB thymomas express the miRNA cluster C19MC. This miRNA cluster known to be the largest in the human genome, is-with expression otherwise restricted mostly to embryonal tissue-silenced in the more aggressive type B thymomas and TCs. Thymomas associated with the autoimmune disease myasthenia gravis (MG) exhibit more frequent gene copy number changes and an increased expression of proteins homologous to molecules that are targets for autoantibodies. TCs, however, display a higher mutational burden, with frequent mutations of TP53 and epigenetic regulatory genes and loss of CDKN2A. The knowledge of molecular alterations in TETs fosters the understanding of their pathogenesis and provides guidance for further studies that may lead to the development of targeted therapies.

Uniportal video-assisted thoracoscopic thymectomy: the glove-port with carbon dioxide insufflation

Background

Since 2004, uniportal video-assisted thoracic surgery (VATS) approach was progressively widespread and also applied in the treatment of thymoma, with promising results. We report the first series of patients who undergone uniportal VATS thymectomy using a homemade glove-port with carbon dioxide (CO₂) insufflation. The aim of this article is to analyze the safety and feasibility to perform an extended thymectomy (ET).

Methods

A prospective, single-centre, short-term observational study including patients with mediastinal tumours undergoing scheduled uniportal VATS resection using a glove-port with CO₂. Operations were performed through a single incision of 3.5 cm at the fifth intercostal space, right or left anterior axillary line. A 5 mm-30° camera and working instruments were employed through a glove-port with CO₂.

Results

Thirty-eight patients (20 men; mean age 61.6 years) underwent ET between September 2016 and October 2019. Thirteen patients had a history of Myasthenia Gravis (MG) with thymoma and 8 had incidental findings of thymoma. Additionally, 8 mediastinal cysts and 9 thymic hyperplasia were included. Mean diameter of the tumor was 5.1 cm (range, 1.6-14 cm) and mean operation time was 143 minutes. Mean postoperative drainage duration and hospital stay were 2.3 and 4.3 days, respectively. Mean blood loss was 41 mL. There was no occurrence of surgical morbidity or mortality. During the follow-up period (1-36 months), no recurrence was noted.

Conclusions

Our results suggest that uniportal VATS thymectomy through glove-port and CO₂ is safe and feasible procedure, even with large thymomas. Furthermore, the glove-port system represents a valid, cheap and widely available alternative to the commercial devices usually adopted in thoracic surgery.

[Transverse myelitis syndrom as a result of neuromyelitis optica spectrum disorders, systemic lupus erythematosus and myasthenia gravis combination]

Neuromyelitis optica spectrum disorders (NMOSD) - autoimmune condition characterized by an inflammatory lesions mainly of the spinal cord with the development of longitudinally extensive transverse myelitis (LETM) and/or involvement of the optic nerve with the development of usually bilateral optical neuritis (ON). In recent years, there has been increased awareness that NMOSD can be combined with other autoimmune diseases, including myasthenia gravis (MG), systemic lupus erythematosus (SLE) et al. The simultaneous presence of several autoimmune diseases in one patient can adversely affect the course of each of the diseases, causing the so-called mutual burden or «overlap syndrome». In this article, we describe our own clinical observation of a 51-year-old woman of European origin who developed acute relapsing TM seropositive for AQP4-IgG, by 23 years after the diagnosis of generalized MG seropositive for antibodies to acetylcholine receptors (AChR-Ab) and the occurrence of SLE, criterially confirmed, several months after the initial TM attack. During the fourth TM attack, partial positive dynamics was achieved only against the background of the combined use of intravenous methylprednisolone (pulse therapy), high-volume plasma exchange, rituximab and cyclophosphamide. The NMOSD is a rare disease leading to severe disability. In patients with MG, when symptoms of damage to the central nervous system appear, an analysis should be performed for AQP4-IgG and possibly for antibodies to myelin glycoprotein of oligodendrocytes (MOG-Ab), as well as markers characteristic of systemic connective tissue diseases (SCTD). In patients with STDD, when symptoms of involvement nervous systemappear, testing for AQP4-IgG (and, if necessary, for MOG-Ab) should be performed to exclude NMOSD, as well as AChR-Ab (and, if necessary, antibodies against muscle specific kinase (MuSK-Ab)) to exclude MG.

Anti-LRP4 Antibody-associated Myasthenia Gravis with a Rare Complication of Thymoma Successfully Treated by Thymectomy

We herein report the case of a 65-year-old woman diagnosed with myasthenia gravis (MG) after complaining of double vision. The patient had anti-low-density lipoprotein receptor-related protein 4 (LRP4) antibody in her serum, although antibodies against the acetylcholine receptor and muscle-specific tyrosine kinase were not detected. Chest computed tomography showed an anterior mediastinal tumor with a high uptake on fluorodeoxyglucose-positron emission tomography. Endoscopic thymectomy successfully ameliorated her ocular symptoms and showed the lesion to be thymoma. The present case revealed that anti-LRP4 antibody-associated MG can be associated with thymoma, which has been regarded as a rare complication of this disease thus far.

Myositis-myasthenia gravis overlap syndrome complicated with myasthenia crisis and myocarditis associated with anti-programmed cell death-1 (sintilimab) therapy for lung adenocarcinoma

Immune checkpoint inhibitors (ICIs) have improved clinical outcomes with a number of advanced malignancies. However, diverse immune-related adverse events (iRAEs) occurred with the widespread use of ICIs, some of which are rarely and life-threatening. Here we report a 66-year-old patient with lung adenocarcinoma who received two doses of sintilimab, a human monoclonal antibody against programmed cell death-1 (PD-1), experienced a fatal storm of iRAEs. He was admitted to the intensive care unit (ICU) by immune induced-myositis/myocarditis and rhabdomyolysis. Despite immediate immunosuppressive therapy with methylprednisolone (MP) and immunoglobulin intravenously, he developed into myositis-myasthenia gravis (MG) overlap syndrome complicated with myasthenia crisis. We commenced plasma exchange (PLEX), mechanical ventilation, immunosuppressive therapy, as well as other supportive therapies. Three months later, the patient's serum creatine phosphate kinase (CPK) and anti-acetylcholine receptor antibody (anti-AChR-Ab) returned to normal despite tumor progression. Herein we discuss the incidence, operating mechanism and management strategies of the fatal iRAEs. Early admission to the ICU and multidisciplinary collaborative treatment for unstable patients with iRAEs could help to achieve a favorable outcome.

Comparison between thoracoscopic and open approaches in thymoma resection

Background

To investigate the feasibility and indications of video-assisted thoracic surgery (VATS) in thymoma resection.

Methods

The clinical data of 103 patients undergoing thymoma resection via different approaches [including conventional lateral thoracotomy approach (LTA) in 41 cases, median sternotomy approach (MSA) in 40 cases, and right-sided VATS in 22 cases] were analyzed. Among them, 59, 13, 25, and 6 patients were in Masaoka stage I, II, III, and IV, respectively. Myasthenia gravis (MG) was also found in 54 cases. The patients were followed up for postoperative survival and the improvement in MG. The prognostic indicators of patients undergoing thymoma resection via different surgical approaches (i.e., LTA, MSA, and VATS) were statistically analyzed.

Results

Eight of 103 patients died. Six patients underwent unilateral sacral nerve resection, among whom 4 patients developed respiratory dysfunction, and 3 died. Two patients died of MG after surgery, 1 patient died of tumor recurrence and metastasis, 1 patient died of heart disease, and the cause of death was unknown in the remaining patient. The drainage time was shorter in VATS group than in open groups, along with smaller tumor size. The VATS group also had shorter hospital stay in the whole series and the subgroup without accompanying MG. The improvement in MG showed no significant difference among the three surgical groups. Both 5- and 10-year survival rates were 91% in the entire cohort.

Conclusions

VATS is like a conventional surgeries for improving MG in thymoma patients with accompanying MG. VATS resection can still be considered for thymoma that only invades the mediastinal pleura. For thymomas that have intact capsules and have not invaded mediastinal pleura, MSA surgery shall be performed to ensure patient safety if the anteroposterior diameters of the tumors are large and the masses have produced severe compression of the innominate vein, even if the tumors are still in the Masaoka stage II. For thymomas with large left-to-right diameters and with most parts of the tumors located in the left thoracic cavity, a left-sided approach (either VATS or an open approach) may be used in the absence of MG; if MG accompanies the condition, an MT approach or a bilateral VATS may be considered. In patients with unilateral pericardial phrenic nerve and/or local pericardial involvement, right-sided VATS thymectomy may be considered for thymomas located at the right side and bilateral VATS surgery can be performed for tumors located at the left side. In summary, VATS is feasible for the treatment of thymoma complicated by MG. VATS can be performed in patients with Masaoka stage I, II and (a certain portion of) III thymoma; for some patients with Masaoka stage II thymoma, especially those with compression of the innominate vein, the use of VATS should be cautious.

Clinical analysis of Chinese anti-low-density-lipoprotein-receptor-associated protein 4 antibodies in patients with myasthenia gravis

BACKGROUND AND PURPOSE

Low-density-lipoprotein-receptor-associated protein 4 (LRP4) autoantibodies have recently been detected in myasthenia gravis (MG), but little is known about the clinical characteristics associated with this serological type. In this study, the clinical features of Chinese patients with anti-LRP4 antibody-positive MG were characterized.

METHODS

A total of 2172 MG serum samples were collected from patients in various parts of China. An enzyme-linked immunosorbent assay was used to detect acetylcholine receptor (AChR) antibody and titin antibody, and cell-based assays were used to detect muscle-specific kinase antibody and LRP4 antibody. Clinical data for patients with MG were collected from different provinces in China.

RESULTS

In total, 16 (0.8%) patients with LRP4-MG were found amongst 2172 total patients, including three patients with AChR/LRP4-MG. Additionally, 13 (2.9%) patients with LRP4-MG were found amongst 455 patients with double seronegative MG. The ratio of males to females for these 13 patients was 1:1.6, and 53.8% patients were children. A total of 91.7% of cases exhibited initial ocular involvement, and 58.3% of cases exhibited simple eye muscle involvement. Responses to acetylcholinesterase inhibitors and prednisone were observed.

CONCLUSION

The expanded sample confirmed that the positive rate of LRP4 antibodies in China is lower than that in western countries. Our results highlighted the differences between LRP4-MG and other antibody groups. Children and female patients with LRP4-MG have a higher prevalence, often involving the ocular muscles and limb muscles. The clinical symptoms are mild, and satisfactory responses to treatment are often achieved.

The Cancer Genome Atlas dataset-based analysis of aberrantly expressed genes by GeneAnalytics in thymoma associated myasthenia gravis: focusing on T cells

Background

Myasthenia gravis (MG) is a group of autoimmune disease which could be accompanied by thymoma. Many differences have been observed between thymoma-associated MG (TAMG) and non-MG thymoma (NMG). However, the molecular difference between them remained unknown. This study aimed to explore the differentially expressed genes (DEGs) between the two categories and to elucidate the possible pathogenesis of TAMG further.

Methods

DEGs were calculated using the RNA-Sequencing data from 11 TAMG and 10 NMG in The Cancer Genome Atlas (TCGA) database. GeneAnalytics was performed to characterize the associations between DEGs and tissues and cells, diseases, gene ontology (GO) terms, pathways, phenotypes, and drug/compounds, respectively. Genes related to T cells were sorted out using LifeMapDiscovery Cells and Tissues Database. Genes directly related to the phenotype of autoimmune diseases that were identified by VarElect were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

Results

The expression level of 169 genes showed a significant difference between the two groups, with 94 up-regulated and 75 down-regulated. Overexpression of six genes (ATM, SFTPB, ANKRD55, BTLA, CCR7, TNFRSF25), which are expressed in T cells and directly related to autoimmune disease through VarElect, was identified. The overexpression of soluble BTLA (sBTLA) (P=0.027), CCR7 (P=0.0018), TNFRSF25 (P=0.0013) and ANKRD55 (P=0.0026) was validated by RT-qPCR in thymoma tissues from our center.

Conclusions

Overexpression of sBTLA, CCR7, TNFRSF25 and ANKRD55 was identified and validated by RT-qPCR, which could partly explain the underlying pathogenesis in TAMG.

Autoimmune Channelopathies at Neuromuscular Junction

The neuromuscular junction, also called myoneural junction, is a site of chemical communication between a nerve fiber and a muscle cell. There are many types of channels at neuromuscular junction that play indispensable roles in neuromuscular signal transmission, such as voltage-gated calcium channels and voltage-gated potassium channels on presynaptic membrane, and acetylcholine receptors on post-synaptic membrane. Over the last two decades, our understanding of the role that autoantibodies play in neuromuscular junction disorders has been greatly improved. Antibodies against these channels cause a heterogeneous group of diseases, such as Lambert-Eaton syndrome, Isaacs' syndrome and myasthenia gravis. Lambert-Eaton syndrome is characterized by late onset of fatigue, skeletal muscle weakness, and autonomic symptoms. Patients with Isaacs' syndrome demonstrate muscle cramps and fasciculation. Myasthenia gravis is the most common autoimmune neuromuscular junction channelopathy characterized by fluctuation of muscle weakness. All these disorders have a high risk of tumor. Although these channelopathies share some common features, they differ for clinical features, antibodies profile, neurophysiological features, and treatments. The purpose of this review is to give a comprehensive insight on recent advances in autoimmune channelopathies at the neuromuscular junction.

Remission of myasthenia gravis following cervical adjustment

Myasthenia gravis (MG) is an autoimmune disorder, caused by circulating antibodies against the acetylcholine receptor (AChR) and associated proteins. Anticholinesterase medications and immunomodulating therapies are the mainstays of current treatment. Presented here is a case of a 51-year-old female who had been diagnosed with MG based on symptoms and continued elevation of antibody to AChR (anti-AChR) by her family physician. The patient's anticholinesterase medication was halted due to significant side effects affecting bowel function. She only received acupuncture treatment in the past 4 months prior to this presentation. Myasthenic symptoms deteriorated and the anti-AChR titer kept elevating after stopping medication. She originally came to us due to neck and back pain rather than myasthenic complaints. This case is interesting that her back pain and myasthenic symptoms went into complete remission within 1 month of initiating chiropractic adjustment. The concomitant recession of the myasthenic symptoms raises considerable interest for the mystery of MG, including the causal link between stress and autoimmune disease, the role of ACh in immune regulation, and the possible mechanisms of disease amelioration. Further studies would shed more light on the efficacy of various modalities in treating MG.

Thymic epithelial tumor complicated by immunological abnormalities: results from a single-center retrospective study in China

Background

To describe the clinical manifestations, immunological features, treatments, and outcomes of patients with thymic epithelial tumor (TET) complicated by immunological abnormalities, and to improve knowledge on immunological abnormalities in this rare disease.

Methods

Patients with pathologically confirmed TET at Beijing Chaoyang Hospital between January 2013 and May 2018 were included in this study, and clinical data were analyzed retrospectively. Immunological abnormalities were classified into two groups as follows: Good syndrome (GS) and autoimmune disease (AD).

Results

Fifty-nine TET patients were enrolled; twenty-two patients (37.3%) had immune dysfunction. There were no gender, age, or histological type differences between groups with or without immunological abnormalities. Six patients had GS, of whom four patients were diagnosed after thymectomy. Recurrent respiratory infections, particularly opportunistic infections, were the most common manifestation. Three GS patients developed a second cancer (50%; P=0.011). Anti-infective therapy and immunoglobulin supplements effectively treated GS. Seventeen patients developed ADs, including myasthenia gravis (MG) (n=13), Hashimoto's thyroiditis (n=4), Sjogren's syndrome (n=1), rheumatoid arthritis (n=1), pemphigus (n=1), and Evans syndrome (n=1). One patient developed both MG and GS and 4 patients presented with two ADs. Three AD cases occurred after thymectomy. Pemphigus and 80% (8/10) of MG cases were resolved following thymectomy.

Conclusions

There is a strong association between immunological abnormalities and TET, which may present at any time point during the disease, even after thymectomy. In addition to infection, GS patients are more likely to develop a second cancer. Thymectomy may produce favorable outcomes for MG in this study, while surgery does not improve immunodeficiency in GS patients.

The Risks and Benefits of Immune Checkpoint Blockade in Anti-AChR Antibody-Seropositive Non-Small Cell Lung Cancer Patients

Background: Anti-programmed cell death 1 (PD-1) monoclonal antibodies (Abs) unleash an immune response to cancer. However, a disruption of the immune checkpoint function by blocking PD-1/PD-ligand 1(PD-L1) signaling may trigger myasthenia gravis (MG) as a life-threatening immune-related adverse event. MG is a neuromuscular disease and is closely associated with being positive for anti-acetylcholine receptor (anti-AChR) Abs, which are high specific and diagnostic Abs for MG. Methods: A 72-year-old man was diagnosed with chemotherapy-refractory lung squamous cell carcinoma and nivolumab was selected as the third-line regimen. We describe the first report of an anti-AChR Ab-seropositive lung cancer patient achieving a durable complete response (CR) to an anti-PD-1 antibody therapy. To further explore this case, we performed multiplex immunofluorescence analysis on a pretreatment tumor. Results: The patient achieved a durable CR without developing MG. However, the levels of anti-AChR Abs were elevated during two years of anti-PD-1 antibody therapy. The tumor of the subclinical MG patient had high PD-L1 expression and an infiltrated–inflamed tumor immune microenvironment. Conclusions: This study suggests that immune checkpoint inhibitors can be safely used and provide the benefits for advanced cancer patients with immunologically ‘hot’ tumor even if anti-AChR Abs are positive. Although careful monitoring clinical manifestation in consultation with neurologist is needed, immune checkpoint inhibitors should be considered as a treatment option for asymptomatic anti-AChR Ab-seropositive cancer patients.

Incidence and clinical variable inter-relationships of thymic epithelial tumors in northwest China

Background

Thymic epithelial tumors (TETs) are the most common primary thymus tumors, but neither the possible ethnical/regional differences in the incidence of TETs nor the inter-relationships among the clinical variables has been revealed in northwest China.

Methods

A retrospective chart review was performed among pathologically confirmed TET patients from January 2004 to December 2015 in a tertiary general hospital of northwest China and the incidence, clinical features and the inter-relationships among clinical variables were analyzed.

Results

A total of 603 pathologically confirmed TETs patients (age range, 5-78 years; 308 males) were enrolled and the most common lesion location was anterior mediastinum (98.5%), among them, 192 (31.8%) had myasthenia gravis (MG). Twenty-six (5.7%), 112 (24.6%), 83 (18.2%), 137 (30.1%), 74 (16.3%), and 23 (5.1%) patients fell into the World Health Organization (WHO) type A, AB, B1, B2, B3 and thymic carcinoma (TC), respectively. The incidence of TETs was slightly higher in the female population and the age group of 40-60 years old. In addition, MG predominantly coexisted with WHO types A-B3 TETs and the TETs with MG were smaller than those without MG. The correct diagnosis rates were 42.3% (77 out of 182), 61.1% (127 out of 208), 89.3% (250 out of 280) and 75.0% (3 out of 4) for chest X-ray, non-contrast computed tomography (CT), contrast CT scan and magnetic resonance imaging (MRI), respectively.

Conclusions

Distinct gender and age differences exist in the incidence of TETs and the A-B3 TETs are closely related with MG. Contrast CT scan plays more important role in diagnosing TETs.

The long noncoding RNA MALAT-1 functions as a competing endogenous RNA to regulate MSL2 expression by sponging miR-338-3p in myasthenia gravis

Myasthenia gravis (MG) is a cell-dependent autoimmune disease commonly associated with thymic pathology. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) has been associated with gene regulation and alternative splicing. It has shown relationship with proliferation, apoptosis, migration, and invasion. In this study, we found that MALAT-1 expression was downregulated in MG. The level of the miR-338-3p was increased in peripheral blood mononuclear cells from MG patients compared with those from control subjects. MALAT-1 competed for binding to miR-338-3p with male-specific lethal 2 (MSL2) in luciferase reporter assays. We confirmed the MALAT-1-miR-338-3p-MSL2 interaction network in MG in vitro. Thus, MALAT-1 directly induced MSL2 expression in MG by acting as a competing endogenous RNA for miR-338-3p, suggesting that it may serve as a therapeutic target for MG treatment.

Relapsed Myasthenia Gravis after Nivolumab Treatment

Nivolumab is a newly introduced promising therapy for treating lung cancer that restores the anti-tumor immunity by disrupting programmed cell death-1-mediated immuno-suppressive signaling. Although "new-onset" autoimmune diseases are well-known immune-related adverse events, whether or not nivolumab exacerbates "pre-existing" autoimmune disease remains unclear. We herein report a patient with "pre-existing" myasthenia gravis in whom nivolumab was administered that flared up after the treatment with nivolumab. Regardless of the disease stability, nivolumab has the potential to exacerbate an autoimmune disease, and we must pay close attention to each patient's medical history before administering this agent.

Myasthenia gravis as a prognostic marker in patients with thymoma

Background

Thymoma is the most common mediastinal tumor, representing <1% of all cancers. It is usually associated with paraneoplastic disorders, mainly myasthenia gravis (MG). The aim of the present study was to describe patients with thymoma and the differences between those with MG and those without it.

Methods

A retrospective 10-year database of the patients with thymoma treated at a single cancer referral hospital (National Institute of Cancer, Mexico City), was analyzed.

Results

Sixty-four files from patients with thymoma were analyzed, 18 of them had MG. The symptoms that occurred most frequently in patients with MG were ptosis, diplopia, appendicular weakness, dysphonia and dysphagia. The most frequent Myasthenia Gravis Foundation of America (MGFA) stage was IIIb followed by stage I. Almost all the patients with MG had positive Acetylcholine Receptor antibodies (P<0.001), with not specified antibodies in four patients. The median overall survival showed a trend to be higher among the patients with MG, but there were no significant differences.

Conclusions

In patients with thymoma MG manifests with different clinical and autoimmune traits, but not survival differences. A larger multi-centric study should be encouraged to evaluate the prognostic implications of having MG in patients with thymoma.

Inter-relationship among myasthenia gravis, WHO histology, and Masaoka clinical stage and effect on surgical methods in patients with thymoma: a retrospective cohort study

Background

The aim of study is to analyze the inter-relationship among WHO histology, myasthenia gravis (MG) and Masaoka stage and to assess the feasibility of thoracoscopic surgery in thymoma patients.

Methods

Data from 142 consecutive thymoma patients from January 2009 to March 2016 were retrospectively reviewed in our institution. Histological classification and clinical staging were assessed by WHO histology criteria and Masaoka stage. We investigated the clinical characteristics, inter-relationship among WHO histology, MG and Masaoka stage, and compared the feasibility and safety of thoracoscopic thymectomy by comparison of open thymectomy.

Results

Among 142 patients, the incidence of MG was 29.6%. Compared with A and AB-type thymomas, a higher prevalence of advance clinical stage was in B1 to C-type thymomas (37/63 vs. 9/43, P<0.001), and there was an increased trend of Masaoka stage from A to C-type thymomas (P<0.001). The incidence of MG was significantly higher in AB, B1 and B2-type thymomas than other type thymomas (23/63 vs. 6/44, P=0.009) and in early Masaoka clinical stage than advanced Masaoka clinical stage (29/80 vs. 12/59, P=0.042). Thoracoscopic surgery could significantly decrease blood loss in patients with (104.06±137.36 vs. 350.91±560.79 mL, P=0.001) or without MG (91.90±77.70 vs. 266.32±292.60 mL, P=0.02), with comparable complications. Additionally, thoracoscopic surgery could achieve an equal effect on the remission of MG with open surgery (7/11 vs. 10/14, P=1.000), and Masaoka stage was significantly associated with the remission of MG after thymectomy.

Conclusions

Our study suggests that WHO histology, MG, and Masaoka stage interrelate with one another, and Masaoka stage is an important prognostic factor in remission of MG after thymectomy in thymoma patients. Thoracoscopic thymectomy could achieve an equal efficacy to open thymectomy and should be recommended as a routine surgery for patients with early Masaoka stage.

Feasible and promising modified trans-subxiphoid thoracoscopic extended thymectomy for patients with myasthenia gravis

Background

We have used a promising, minimally invasive thoracoscopic technique of extended thymectomy for patients with myasthenia gravis (MG). The aim of this study was to report our promising technique, a modified single-port trans-subxiphoid approach (MTXA) and to compare perioperative outcomes and effects on MG between our approach and sternotomy.

Methods

We retrospectively reviewed records of all patients undergoing extended thymectomy for MG and/or thymoma between January 1, 2010 and December 31, 2016. The patients were divided into the MTXA group and Sternotomy group.

Results

Of the 50 consecutive patients undergoing extended thymectomy for MG, finally, 13 patients undergoing our MTXA extended thymectomy technique were compared with 20 patients undergoing extended thymectomy via sternotomy. Intraoperative blood loss, postoperative length of stay, and C-reactive protein value on postoperative day 1 were significantly more favorable in the MTXA group than the Sternotomy group (P<0.0001, P=0.0040 and P=0.0073, respectively). Furthermore, no significant differences in the frequency of patients with improvement of their Quantitative Myasthenia Gravis score and/or MG-Activities of Daily Living scale, decrease in the serum level of acetylcholine receptor antibody, and dose reduction of oral prednisone were seen between the two groups.

Conclusions

Our approach to extended thymectomy might be more favorable than sternotomy in patients with MG.

Robotic-assisted thoracoscopic surgery thymectomy

In recent decades, mediastinal surgery has undergone radical innovations. In fact, introduction of minimally invasive methods, such as video-assisted thoracoscopic surgery (VATS), showed several clinical benefits over median sternotomy. Recently the introduction of robotic-assisted thoracoscopic surgery (RATS) has added more technological advantages in mediastinal dissection such as 3-dimensional (3D) vision and multi-articulated instruments. We agree with many authors about the advantages of RATS for the treatment of patients with thymomas and patients with myasthenia gravis (MG) resistant to medical treatment, but actually we express concerns about the high costs of this procedure. Furthermore we are waiting for long term clinical and oncological outcomes compared with trans-sternal or VATS approach. Here we report our series experience.

Subxiphoid uniportal VATS thymectomy

Background

To present the technique of minimally invasive extended thymectomy performed through the uniportal subxiphoid approach, with double elevation of the sternum for nonthymomatous myasthenia gravis (MG).

Methods

Operative technique: the whole dissection was performed through the 4-7 cm transverse or longitudinal subxiphoid incision with use of videothoracoscope. The sternum was elevated with two hooks connected to the sternal frame (Rochard bar, Aesculap-Chifa, Nowy Tomysl, Poland). The lower hook was inserted through the subxiphoid incision and the superior hook was inserted percutaneously, after the mediastinal tissue including the major mediastinal vessels were dissected from the inner surface of the sternum. The fatty tissue of the anterior mediastinum and the aorta-pulmonary window was completely removed.

Results

There were four patients in the period 1.1.2017-30.4.2017. There was no mortality and morbidity.

Conclusions

The uniportal subxiphoid approach combined with double elevation of the sternum enabled very extensive thymectomy in case of thymoma.

The Zakopane Pulmonary Hospital experience on subxiphoid thymectomy

BACKGROUND

To present the technique of minimally invasive extended thymectomy performed through the subxiphoid-bilateral subcostal video-assisted thoracoscopic surgery (VATS) approach, with double elevation of the sternum for nonthymomatous myasthenia gravis (MG).

METHODS

The whole dissection was performed through the 4-7 cm transverse subxiphoid incision with single 10 mm extra-long bariatric laparoscopy ports inserted subcostally to the right and left chest cavities for videothoracoscope and subsequently for chest tubes. The sternum was elevated with two hooks connected to the sternal frame (Rochard bar, Aesculap-Chifa, Nowy Tomysl, Poland). The lower hook was inserted through the subxiphoid incision and the superior hook was inserted percutaneously, after the mediastinal tissue including the major mediastinal vessels were dissected from the inner surface of the sternum. The fatty tissue of the anterior mediastinum and the aorta-pulmonary window was completely removed.

RESULTS

There were 147 patients (62 patients operated on for thymomas, 75 patients for nonthymomatous MG and 10 for rethymectomies) in the period 1.1.2009-30.3.2016. There was no mortality and morbidity. The mean operative time was 109.1 min (range, 75-150 min).

CONCLUSIONS

The subxiphoid approach combined with bilateral single port subcostal VATS and double elevation of the sternum enables very extensive thymectomy in case of nonthymomayous MG.

VATS thymectomy for early stage thymoma and myasthenia gravis: combined right-sided uniportal and left-sided three-portal approach

The traditional approach to thymectomy requires median sternotomy based on the assumption that it is the best means to achieve adequate resection margins, complete removal of the thymus and clearance of the anterior mediastinal fat. However, in recent years, VATS thymectomy has been gaining acceptance as a means to achieve adequate oncologic results and symptomatic improvement of myasthenic symptoms with less impact on the patient. We have adopted a flexible approach based on the location of the tumor and on whether the patient has myasthenia gravis (MG) or not when planning minimally invasive VATS thymectomy. A preferential approach from the left side is chosen for clinical stage I-II thymomas located on the left side or on the midline in patients without MG, and a bilateral approach (uniportal VATS on the right side and three-portal VATS on the left side) for MG patients with or without thymoma in order to achieve complete clearance of the anterior mediastinal fat on both sides. Such techniques are herewith clearly illustrated in hope that surgeons wishing to endeavor in such an effort will be facilitated.

The results of video-assisted thoracoscopic thymectomies in Saint Petersburg, Russia: 20-year of experience

BACKGROUND

During the period from 1996 to 2016, we have performed 281 thymectomies in patients with various diseases of the thymus. In 179 patients, thymic pathology was associated with autoimmune myasthenia gravis (MG), and, in 108 patients, thymoma was diagnosed.

METHODS

The majority of surgeries [254] were performed using video thoracoscopy, 79 of them with an additional cervical approach. The long-term results of video thoracoscopic thymectomies in myasthenic patients were followed up for 1 to 15.5 years.

RESULTS

In 26% of the patients, a complete and stable remission was achieved, in 47%-clinical manifestation improved. Local recurrence of thymoma developed in one patient (0.9%).

CONCLUSIONS

Comparison of postoperative complications and long-term results demonstrated that extended video-assisted thoracoscopic thymectomy (VATS-TE) is a radical, efficient, safe, technically feasible and a well-tolerated surgery. It improves the course of MG as a part of multimodality treatment more efficiently than a conservative therapy alone. The course of MG after VATS-TE shows that the cumulative incidence of remissions/improvements reaches its maximum by the 3rd year after the surgery. VATS-TE is radical and safe for removal of noninvasive thymomas up to 8 cm in size. Additional neck incision (VATS-TE + cervical approach) does not provide further advantages, but rather may be a cause of specific postoperative complications.

Definitions and standard indications of minimally-invasive techniques in thymic surgery

BACKGROUND

The minimally invasive thoracic procedures are those performed through the intercostal, subxiphoid, subcostal or transcervical incisions. In most of these procedures (with exception of some transcervical procedures) the video-assisted thoracic surgery (VATS) technique is used for performance of an operation under guidance of a video monitor.

METHODS

According to the definition the minimally invasive procedures do not include the sternal manubriotomy (upper sternal split), transverse sternotomy and subcutaneous longitudinal sternotomy. Currently, a minimally invasive extended thymectomy became a widespread procedure advised for nonthymomatous myasthenia gravis (MG) and early-stage thymomas. The definition of an extended thymectomy is a removal of the whole thymus with the surrounding adipose tissue. Instead of the term "extended thymectomy" some authors recommended a term "complete thymectomy", which means total removal of the whole thymus, without the adjacent fatty tissue.

RESULTS

There are a lot of doubts about the definition of extended thymectomy. There have been no prospective randomized trials comparing the transsternal and minimally invasive approaches for MG or thymomas. Possible scenarios for such trials are analyzed in this paper.

CONCLUSIONS

There are several issues of a minimally invasive thymectomy for MG and thymomas necessitating further clarifications.

Extended thymectomy by a cervical incision additional to bilateral VATS approach

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) in thymectomy has shown safe and effective with many advantages in myasthenia gravis (MG) patients with or without thymoma than transsternal approach. This video aims to show the procedure of extended thymectomy via a cervical incision additional to bilateral VATS approach in a MG patient with an early stage thymoma.

METHODS

The patient was a 46-year-old male who had onset of symptoms of blurred vision, dysarthria and dysphagia for 10 months before administration. A diagnosis of MG was then confirmed using anticholinesterase test and electromyography test by neurologists. A CT scan showed enlarged thymus and a mass close to the left innominate vein in the anterior mediastinum with a size of 12 mm × 13 mm. Without any contradictions, the patient was planned to receive a procedure of extended thymectomy.

RESULTS

The patient recovered with no complications and was discharged on the 8th postoperative day. Histological pathology examination revealed a type B3 thymoma of Masaoka stage II.

CONCLUSIONS

Oncological principles and immunological considerations are equally important in surgery for the MG patients with thymoma. All the thymus gland in the mediastinum including ectopic thymic tissue in the cervical region should be removed in the procedure. In conclusion, we suggest this approach to be safe and feasible for thymoma surgery in patients with MG.

Robotic thymectomy

Thymectomy is the most frequent surgical operation involving the mediastinum, both for the treatment of thymic tumors and for the multidisciplinary management of myasthenia gravis (MG). Different surgical approaches have been described, either traditional open approaches or minimally invasive ones. Robotic thymectomy represents a further step in the evolution of minimally invasive surgery. Available data show that robotic thymectomy may be considered a safe and feasible operation, with encouraging long-term results in myasthenic patients and promising results in patients with early stage thymoma, both in terms of surgical and oncological outcomes. We present the surgical technique of robotic thymectomy that we apply for patients affected by myasthenia gravis and early stage thymoma.

Left video-assisted thoracic surgery thymectomy

Video-assisted thoracic surgery (VATS) for the management of non-thymomatous myasthenia gravis (MG) as well as the management of small thymomas and other benign thymic pathology has been gaining in acceptance and popularity as an alternative to the traditional median sternotomy approach. Although VATS thymectomy has been described in several variations, our current preference is a left sided VATS approach due to the exposure it provides in critical areas of dissection. Here we describe our technique for the left sided VATS thymectomy including patient selection, preoperative preparation, operative steps, and postoperative care. We also share pitfalls and tips to prevent them at each step of the procedure learned from our experience with this approach.

Postoperative survival for patients with thymoma complicating myasthenia gravis-preliminary retrospective results of the ChART database

BACKGROUND

It is so far not clear that how myasthenia gravis (MG) affected the prognosis of thymoma patients. The aim of this assay is to compare the postoperative survival between patients with thymoma only and those with both thymoma and MG.

METHODS

The Chinese Alliance for Research in Thymomas (ChART) registry recruited patients with thymoma from 18 centers over the country on an intention to treat basis from 1992 to 2012. Two groups were formed according to whether the patient complicated MG. Demographic and clinical data were reviewed, patients were followed and their survival status were analyzed.

RESULTS

There were 1,850 patients included in this study, including 421 with and 1,429 without MG. Complete thymectomy were done in 91.2% patients in MG group and 71.0% in non-MG group (P<0.05). There were more percentage of patients with the histology of thymoma AB, B1, or B2 (P<0.05) in MG group, and more percentage of patients with MG were in Masaoka stage I and II. The 5- and 10-year overall survival (OS) rates were both higher in MG group (93% vs. 88%; 83% vs. 81%, P=0.034) respectively. The survival rate was significantly higher in patients with MG when the Masaoka staging was 3/4 (P=0.003). Among patients with advanced stage thymoma (stage 3, 4a, 4b), the constituent ratios of 3, 4a, 4b were similar between MG and non-MG group. Histologically, however, there were significantly more proportion of AB/B1/B2/B3 in the MG group while there were more C in the non-MG group (P=0.000). Univariate analyses for all patients showed that MG, WHO classification, Masaoka stage, surgical approach, chemotherapy and radiotherapy and resectability were significant factors, and multivariate analysis showed WHO classification, Masaoka stage, and resectability were strong independent prognostic indicators.

CONCLUSIONS

Although MG is not an independent prognostic factor, the survival of patients with thymoma was superior when MG was present, especially in late Masaoka stage patients. Possible reasons included early diagnosis of the tumor, better histologic types, an overall higher R0 resection and less recurrence.

Thymectomy versus tumor resection for early-stage thymic malignancies: a Chinese Alliance for Research in Thymomas retrospective database analysis

BACKGROUND

To evaluate the surgical outcomes of tumor resection with or without total thymectomy for thymic epithelial tumors (TETs) using the Chinese Alliance for Research in Thymomas (ChART) retrospective database.

METHODS

Patients without preoperative therapy, who underwent surgery for early-stage (Masaoka-Koga stage I and II) tumors, were enrolled for the study. They were divided into thymectomy and thymomectomy groups according to the resection extent of the thymus. Demographic and surgical outcomes were compared between the two patients groups.

RESULTS

A total of 1,047 patients were enrolled, with 796 cases in the thymectomy group and 251 cases in the thymomectomy group. Improvement rate of myasthenia gravis (MG) was higher after thymectomy than after thymomectomy (91.6% vs. 50.0%, P<0.001). Ten-year overall survival was similar between the two groups (90.9% after thymectomy and 89.4% after thymomectomy, P=0.732). Overall, recurrence rate was 3.1% after thymectomy and 5.4% after thymomectomy, with no significant difference between the two groups (P=0.149). Stratified analysis revealed no significant difference in recurrence rates in Masaoka-Koga stage I tumors (3.2% vs. 1.4%, P=0.259). However in patients with Masaoka-Koga stage II tumors, recurrence was significantly less after thymectomy group than after thymomectomy (2.9% vs. 14.5%, P=0.001).

CONCLUSIONS

Thymectomy, instead of tumor resection alone, should still be recommended as the surgical standard for thymic malignancies, especially for stage II tumors and those with concomitant MG.

Multi-institutional European experience of robotic thymectomy for thymoma

BACKGROUND

Robotic thymectomy for early-stage thymomas has been recently suggested as a technically sound and safe approach. However, due to a lack of data on long term results, controversy still exists regarding its oncological efficacy. In this multi-institutional series collected from four European Centres with high volumes of robotic procedures, we evaluate the results after robot-assisted thoracoscopic thymectomy for thymoma.

METHODS

Between 2002 and 2014, 134 patients (61 males and 73 females, median age 59 years) with a clinical diagnosis of thymoma were operated on using a left-sided (38%), right-sided (59.8%) or bilateral (2.2%) robotic approach. Seventy (52%) patients had associated myasthenia gravis (MG).

RESULTS

The average operative time was 146 minutes (range, 60-353 minutes). Twelve (8.9%) patients needed open conversion: in one case, a standard thoracoscopy was performed after robotic system breakdown, and in six cases, an additional access was required. Neither vascular and nerve injuries, nor perioperative mortality occurred. A total of 23 (17.1%) patients experienced postoperative complications. Median hospital stay was 4 days (range, 2-35 days). Mean diameter of resected tumors was 4.4 cm (range, 1-10 cm), Masaoka stage was I in 46 (34.4%) patients, II in 71 (52.9%), III in 11 (8.3%) and IVa/b in 6 (4.4%) cases. At last follow up, 131 patients were alive, three died (all from non-thymoma related causes) with a 5-year survival rate of 97%. One (0.7%) patient experienced a pleural recurrence.

CONCLUSIONS

Our data suggest that robotic thymectomy for thymoma is a technically feasible and safe procedure with low complication rates and short hospital stays. Oncological outcome appears to be good, particularly for early-stage tumors, but a longer follow-up period and more cases are necessary in order to consider this as a standard approach. Indications for robotic thymectomy for stage III or IVa thymomas are rare and should be carefully evaluated.

Clinical Outcomes of Myasthenia Gravis with Thymoma and Thymic Hyperplasia Undergoing Extended Transsternal Thymectomy: A Single-Center Experience

BACKGROUND

Despite the widespread use of thymectomy in myasthenia gravis (MG) patients, it has remained controversial as to whether this procedure is of a similar efficacy and clinical outcome among MG patients with thymoma and thymic hyperplasia.

AIM

We sought to determine the long-term clinical outcomes of MG patients who received extended transsternal thymectomy associated with pyridostigmine and prednisolone postoperatively.

MATERIALS AND METHODS

In a retrospective study from January 1999 to December 2013, MG patients who underwent thymectomy were followed up. Out of 41 MG patients admitted in our center, 25 patients had undergone thymectomy adjunctive to pyridostigmine and prednisolone therapy postoperatively. The primary endpoints included improvement in individual diplopia, ptosis, dysphagia, dysarthria, dyspnea, and limb weakness. In addition, according to the MG Foundation of America (MGFA) criteria, response to therapy was defined as complete stable remission (CSR), pharmacologic remission (PR), and minimal manifestation (MM) as secondary endpoints.

RESULTS

Majority of the patients were male (60%) and the mean age of the patients was 32.2 ± 13.9 years. Fifteen (60%) and 10 patients (40%) had thymoma and thymic hyperplasia, respectively. All the patients were followed up during a mean period of of 86.9 ± 50.3 months (minimum 10 months and maximum 168 months). The rates of CSR, PR, and MM were comparable between the thymoma and thymic hyperplasia groups (P = 0.584). Based on the Kaplan Meier analysis, the probabilities of CSR, PR, and MM were not significantly different between patients with thymoma and thymic hyperplasia.

CONCLUSION

The extended transsternal thymectomy, along with the postoperative regimen of pyridostigmine and prednisolone was associated with a high rate of clinical improvement among MG patients with thymoma or thymic hyperplasia.

Minimally invasive thymectomy: the Mayo Clinic experience

BACKGROUND

The prevalence of minimally invasive thymectomy (MIT) is increasing and may have significant benefit to patients in terms of morbidity and post-operative recovery. Our aim was to review the Mayo Clinic experience of MIT.

METHODS

We reviewed data from all MIT cases collected in a prospectively maintained database from January 1995 to February 2015. Data were collected regarding patient demographics, perioperative management and patient outcomes.

RESULTS

A total of 510 thymectomies were performed in 20 years. Fifty-six patients underwent MIT (45 video-assisted thoracoscopy, 11 robotic-assisted). The median age was 55 years (range, 23-87 years) with male to female ratio of 25:31. Thymoma was the main pathologic diagnosis in 27/56 patients (48%), with 11/27 (41%) associated with myasthenia gravis (MG), and 16/27 (59%) non-MG. Other pathologies included 1/56 (2%) of each teratoma, lymphoma, lymphangioma, carcinoma and thymolipoma. There were 3/56 (5%) atrophic glands, 4/56 (7%) cysts, 6/56 (11%) benign glands and 11/56 (20%) hyperplastic. Mean blood loss (mL) and operative time (min) were significantly lower in the video-assisted thoracoscopic surgery (VATS) group compared to robotic (65±41 vs. 160±205 mL, P=0.04 and 102±39 vs. 178±53 min, P=0.001, respectively). There was no 30-day mortality. Post-operative morbidity occurred in 7/45 (16%) VATS patients (phrenic nerve palsy 7%, pericarditis 4%, atrial fibrillation 2%, pleural effusion 2%) and 1/11 (9%) robotic (urinary retention requiring self-catheterization). Reoperation was required in 1/3 of VATS patients with phrenic nerve palsy. There was no significant difference in length of hospital stay [VATS 1.5 days (range, 1-4 days) and robotic 2 days (range, 1-5 days) VATS; P=0.05]. Mean follow-up was 18.4 months (range, 1-50.4 months) with no tumor recurrences.

CONCLUSIONS

MIT can be performed with low morbidity and mortality. VATS is associated with reduced blood loss, operative times and earlier hospital discharge compared to robotic MIT.