An update on thymectomy in myasthenia gravis

Long-term prognosis in patients with thymoma combined with myasthenia gravis: a propensity score-matching analysis

Introduction

We aimed to assess the impact of myasthenia gravis (MG) on the long-term prognosis in patients with thymoma after surgery and identify related prognostic factors or predictors.

Methods

This retrospective observational study included 509 patients with thymoma (thymoma combined with MG [MG group] and thymoma alone [non-MG group]). Propensity score matching was performed to obtain comparable subsets of 96 patients in each group. A comparative analysis was conducted on various parameters.

Results

Before matching, the 10-year survival and recurrence-free survival rates in both groups were 93.8 and 98.4%, and 85.9 and 93.4%, respectively, with no statistically significant difference observed in the survival curves between the groups (p > 0.05). After propensity score matching, 96 matched pairs of patients from both groups were created. The 10-year survival and recurrence-free survival rates in these matched pairs were 96.9 and 97.7%, and 86.9 and 91.1%, respectively, with no statistical significance in the survival curves between the groups (p > 0.05). Univariate analysis of patients with thymoma postoperatively revealed that the World Health Organization histopathological classification, Masaoka-Koga stage, Tumor Node Metastasis stage, resection status, and postoperative adjuvant therapy were potentially associated with tumor recurrence after thymoma surgery. Multivariate analysis demonstrated that the Masaoka-Koga stage and postoperative adjuvant therapy independently predicted the risk of recurrence in patients with thymoma after surgery.

Conclusion

There was no difference in prognosis in patients with thymoma with or without MG. The Masaoka-Koga stage has emerged as an independent prognostic factor affecting recurrence-free survival in patients with thymoma, while postoperative adjuvant therapy represents a poor prognostic factor.

Improving Outcome in Severe Myasthenia Gravis and Guillain-Barré Syndrome

When progressive and severe, myasthenia gravis and Guillain-Barré syndrome may have the potential for fatal and unfavorable clinical outcomes. Regardless of important differences in their clinical course, the development of weakness of oropharyngeal muscles and respiratory failure with requirement of mechanical ventilation is the main driver of poor prognosis in both conditions. The need for prolonged mechanical ventilation is particularly relevant because it immobilizes the patient and care becomes extraordinarily complex due to daily risks of systemic complications. Additionally, patients with myasthenia gravis often require long-term immunosuppressive treatments with associated toxicity and infectious risks. Unlike myasthenia gravis, the recovery period is prolonged in Guillain-Barré syndrome, but often favorable, even in the more severely affected patients. Outcome, for a large part, is determined by expert neurocritical care.

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.

Thymoma-associated autoimmune encephalitis with myasthenia gravis: Case series and literature review

OBJECTIVES

This comprehensive review aimed to compile cases of patients with thymoma diagnosed with both autoimmune encephalitis (AE) and myasthenia gravis (MG), and describe their clinical characteristics.

METHODS

Clinical records of 3 AE patients in the first affiliated hospital of Sun Yat-sen University were reviewed. All of them were diagnosed with AE between 1 November 2021 and 1 March 2022, and clinical evidence about thymoma and MG was found. All published case reports were searched for comprehensive literature from January 1990 to June 2022.

RESULTS

A total of 18 cases diagnosed with thymoma-associated autoimmune encephalitis (TAAE) and thymoma-associated myasthenia gravis (TAMG) were included in this complication, wherein 3 cases were in the first affiliated hospital of Sun Yat-sen University and the other 15 were published case reports. 5/18 patients had alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antibody (AMPAR-Ab) in their serum and cerebrospinal fluid (CSF). All of them had positive anti-acetylcholine receptor antibody (AChR-Ab). And 12/18 patients showed a positive response to thymectomy and immunotherapy. Besides, thymoma recurrences were detected because of AE onset. And the shortest interval between operation and AE onset was 2 years in patients with thymoma recurrence.

CONCLUSIONS

There was no significant difference in the clinical manifestations between these patients and others with only TAMG or TAAE. TAAE was commonly associated with AMPAR2-Ab. Significantly, AE more commonly heralded thymoma recurrences than MG onset. And the intervals of thymectomy and MG or AE onset had different meanings for thymoma recurrence and prognoses of patients.

National Multicenter Study on the Comparison of Robotic and Open Thymectomy for Thymic Neoplasms in Myasthenic Patients: Surgical, Neurological and Oncological Outcomes

Thymectomy is the gold standard in the treatment of thymic neoplasm and plays a key role in the therapeutic path of myasthenia gravis. For years, sternotomy has been the traditional approach for removing anterior mediastinal lesions, although the robotic thymectomy is now widely performed. The literature is still lacking in papers comparing the two approaches and evaluating long-term oncological and neurological outcomes. This study aims to analyze the postoperative results of open and robotic thymectomy for thymic neoplasms in myasthenic patients. Surgical, oncological and neurological data of myasthenic patients affected by thymic neoplasms and surgically treated with extended thymectomy, both with the open and the robotic approach, in six Italian Thoracic Centers between 2011 and 2021 were evaluated. A total of 213 patients were enrolled in the study: 110 (51.6%) were treated with the open approach, and 103 (48.4%) were treated with robotic surgery. The open surgery, compared with the robotic, presented a shorter operating time (p < 0.001), a higher number of postoperative complications (p = 0.038) and longer postoperative hospitalization (p = 0.006). No other differences were observed in terms of surgical, oncological or neurological outcomes. The robotic approach can be considered safe and feasible, comparable to the open technique, in terms of surgical, oncological and neurological outcomes.

Combined effect of thymectomy on myasthenia gravis in patients with concomitant auto-immune diseases: a 22-year single-center experience

Myasthenia gravis (MG) is an autoimmune disease (AD), and patients with MG often have other types of ADs. We analyzed the prognosis of patients with MG complicated by AD after thymectomy. A retrospective analysis was performed for patients with MG complicated by ADs treated surgically in our center over the past 22 years, and their general condition and follow-up data were collected and analyzed. 33 patients were included totally. 28 patients displayed improvement or even complete recovery of MG, and 23 of 36 ADs revealed improvement or even complete recovery. The prognosis of MG is significantly correlated with the duration of postoperative follow-up time (p = 0.028), and in patients with thymoma, the larger the tumor diameter, the better the prognosis of MG (p = 0.026). Thymic hyperplasia patients were predominantly female (p = 0.049) and young (p < 0.001). The most common concomitant AD in this study was a thyroid-associated AD, which was associated with thymic hyperplasia (p < 0.001), Osserman type I MG (p < 0.001), and young age (p < 0.001). Thymectomy had a good therapeutic effect on MG complicated by AD, and there was a close correlation between surgery, thymus, MG, and ADs.

Clinical Comparative Analyses of Thymectomy Between Subxiphoid and Subcostal Arch Thoracoscopic Resection and Median Sternotomy for the Treatment of Thymoma With Myasthenia Gravis in Chinese Patients

INTRODUCTION

This study aims to retrospectively compare the efficacy and safety of subxiphoid and subcostal arch thoracoscopic resection (SR) and the median sternotomy (MS) for thymoma with myasthenia gravis (MG) via propensity-matched analysis.

METHODS

We retrospectively analyzed 502 patients with thymoma and MG in Tangdu Hospital of the Fourth Military Medical University from December 2012 to December 2017. The patients were allocated to SR group (n = 424) and MS group (n = 78). Perioperative outcomes were compared between SR group and MS group by using propensity-matched analysis.

RESULTS

All SR and MS operations were accomplished successfully. Most postoperative outcomes between the two groups showed no significant difference such as remission of MG and postoperative complication (P > 0.05). There were statistically significant differences between MS group and SR group in operation time [(116.3 ± 33.7) min versus (52.2 ± 31.3) min], intraoperative blood loss [(145.2 ± 26.7) mL versus (51.2 ± 10.3) mL], chest drainage duration (3.4 d versus 0 d), days of hospital-stay (5.2 d versus 2.7 d), patient satisfaction score (5.9 ± 2.3 versus 8.7 ± 1.2), the incidence of complications and pain scores, with all P values < 0.05.

CONCLUSIONS

This study suggests that subxiphoid and subcostal arch thoracoscopic resection is a less invasive procedure with good safety and feasibility as compared with median sternotomy for thymoma with myasthenia gravis.

Learning Curve of Robot-Assisted Thymectomy: Single Surgeon's 7-Year Experience

Background

Robot-assisted thymectomy (RAT) has rapidly emerged as the preferred approach over open trans-sternal or video-assisted thoracoscopy for the surgical treatment of thymomas and non-thymomatous myasthenia gravis (MG). The aim of this study was to describe and discuss the learning curve (LC) of a single surgeon performing 113 consecutive RATs.

Methods

A single-center retrospective analysis of prospectively collected clinical data was performed on all patients who had been operated on by the same surgeon in an RAT setting between October 2013 and February 2020. The cumulative sum (CUSUM) analysis of the operative time was used to define the completion of the learning curve (CLC) in RAT. The CLC was separately calculated for myasthenic patients, non-myasthenic patients, and docking time.

Results

In myasthenic patients, the CLC cut-off was found in 19 patients. Considering the CLC cut-off of 19 patients, the mean operative time in phase 1 (first 19 cases) was 229.79 ± 93.40 min, while it was 167.35 ± 41.63 min in phase 2 (last 51 cases), p≪0.001. In non-myasthenic patients, the CLC cut-off was found in 16 cases. The mean operative time in phase 1 (first 16 cases) was 277.44 ± 90.50 min, while it was 169.63 ± 61.10 min in phase 2 (last 27 cases), p = 0.016. The LC for docking time was reached at 46 cases, recording a significant reduction of time after the first phase (28.09 ± 5.37 min vs. 19.75 ± 5.51 min, p≪0.001). The intraoperative and 30-day mortality were null in all phases of the LC in both myasthenic and non-myasthenic patients. There were no differences between the two phases of the LC in terms of blood loss, duration of postoperative drainage, and postoperative stay in both myasthenic and non-myasthenic groups. However, significantly higher hospital readmission at 30 days post surgery was recorded for myasthenic patients operated on during the first phase of the LC (2 cases vs. 0, p = 0.02).

Conclusions

According to our data, LC in RAT seems to be steep, and RAT confirms to be safe even before reaching CLC.

Effect of myasthenia gravis on the surgical outcomes of patients with thymoma

BACKGROUND

Myasthenia gravis (MG) is the most common paraneoplastic syndrome in thymoma. However, the association between MG and postoperative outcomes is controversial. Therefore, we examined the effect of MG on the surgical outcomes of patients with thymoma.

METHODS

This study enrolled 145 consecutive patients with thymoma who underwent surgical resection at our institution between January 2000 and December 2020. The patients were classified into thymoma with MG (MG group) and without MG (non-MG group). Data about characteristics of patients, surgical outcomes, and prognostic factors were compared between the two groups.

RESULTS

Of 145 patients, 47 (32%) presented with MG and 98 (68%) did not. There was no significant difference in terms of the incidence of postoperative complications, overall survival (OS), and recurrence-free survival (RFS) between the two groups. The deaths were not caused by thymoma. Among the patients aged >60 years, the MG group had a lower survival rate than the non-MG group. In the univariate analysis, age ≥60 years was a poor prognostic factor for OS, whereas in the multivariate analysis, Masaoka stage III and IV classifications were poor prognostic factors for RFS.

CONCLUSION

The incidence of postoperative complications did not differ between patients with thymoma and without MG. In the MG group, age ≥60 years was a poor prognostic factor for OS. The postoperative follow-up of patients aged ≥60 years with thymoma with MG should focus on not only recurrence but also progression of diseases other than thymoma.

Thymectomy for treatment of anti-NMDA receptor encephalitis

In this case report, we present a 25-year-old woman who was diagnosed with anti-NMDA receptor encephalitis and subsequently was found to have thymic hyperplasia. She underwent robotic bilateral access thymectomy for treatment of her anti-NMDA receptor encephalitis and has remained asymptomatic after her operation without any medication. This is only the second reported case of thymectomy for treatment of this condition. This case may further suggest thymic tissue is involved in the development of anti-NMDA receptor encephalitis and that thymectomy is an appropriate treatment for a subset of patients with this disease.

PARANEOPLASTIC SYNDROMES REVIEW: THE GREAT FORGOTTEN ONES

Paraneoplastic syndromes (PNS) are a group of disorders that can affect the oncologic patient, and which are not directly attributable to tumour invasion, tumour compression or metastasis. In fact, they are due to tumour secretion of functional hormones or peptides or are related to immune cross-reactivity with the host tissue. These syndromes are called paraneoplastic because the components that cause them do not derive from the organ or tissue of origin, but from the neoplasm suffered by the patient. It is estimated that 10-15% of people with cancer suffer from a PNS.(1) PNS is the second direct cause of death (27% of cases) in cancer patients, after cancer itself. Consequently, it is of remarkable importance to recognize and treat SPNs specifically.(2) In view of the above, the aim of this article is to review the state of the art in neurological, haematological, endocrine, and dermatological paraneoplastic syndromes. It is a review in which the most relevant PNS and their symptomatology are described, inquiring into their diagnosis and treatment.

Childhood-Onset Myasthenia Gravis Patients Benefited from Thymectomy in a Long-Term Follow-up Observation

INTRODUCTION

 The effect of thymectomy on the treatment of childhood-onset myasthenia gravis (CMG) remains debatable. The objective of this study was to evaluate the clinical outcome and relevant prognostic factors of thymectomy for CMG patients.

MATERIALS AND METHODS

 A total of 32 CMG patients who underwent thymectomy before 18 years of age were included in this retrospective study. Clinical state following thymectomy was assessed by quantified myasthenia gravis (QMG) scores, myasthenia gravis-related activities of daily living (MG-ADL) scores, and Myasthenia Gravis Foundation of America postintervention status. Repeated-measures analysis of variance (ANOVA) examined the changes in postoperative scores during the 5-year follow-up. Univariate logistic regression was applied to identify factors associated with short-term (1-year postoperation) and long-term (5-year postoperation) clinical outcomes.

RESULTS

 Repeated-measures ANOVA showed that QMG scores (F = 6.737, p < 0.001) and MG-ADL scores (F = 7.923, p < 0.001) decreased gradually with time. Preoperative duration (odds ratio [OR] = 0.85, 95% confidence interval [CI]: 0.73-1.00, p = 0.043), gender (OR = 0.19, 95% CI: 0.04-0.94, p = 0.041), and MG subgroup (OR = 13.33, 95% CI: 1.43-123.99, p = 0.023) were predictors for 1-year postoperative prognosis. Shorter disease duration (OR = 0.82, 95% CI: 0.70-0.97, p = 0.018) and generalized CMG (OR = 6.11, 95% CI: 1.06-35.35, p = 0.043) were found to have more favorable long-term results.

CONCLUSION

 Our results suggest that thymectomy is effective in treating CMG. Thymectomy could be recommended for CMG patients, especially for patients in the early course of GMG.

Myasthenia gravis in an old woman discovered during sedation for diagnostic digestive fibroscopy: Case report

Introduction and importance: Myasthenia gravis is an autoimmune disease characterized by the destruction of postsynaptic acetylcholine receptors in skeletal striated muscles. It is most common in young women. Myasthenia can be diagnosed by the detection of anti-acetylcholine receptor antibodies. Treatment includes anticholinesterase drugs, thymectomy, and restricting drugs that may aggravate myasthenia. The authors report a rare case of accidental revelation of myasthenia gravis in an elderly woman during sedation for diagnostic gastrointestinal fibroscopy. Case presentation: A 85-years-old female patient scheduled for diagnostic gastrointestinal fibroscopy presented signs of myasthenic crisis during the perioperative with severe respiratory failure. The diagnosis of myasthenia was confirmed by bioassay and electromyogram (EMG). Her chest CT scan showed a thymoma. The evolution was favorable as a result of early and appropriate management. Conclusion: Myasthenia can occur in perioperative settings outside the usual circumstances. The prognosis depends on early and adapted management.

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Myasthenia gravis is rare in women of advanced age.

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The myasthenic crisis can be inaugural of the disease whatever the age without distinction of sex.

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This case reports a form of discovery of the myasthenic crisis outside the usual circumstance.

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The early diagnosis and the implementation of a medical treatment allow extubating the patient quickly and successfully.

Robotic thymectomy for thymoma in patients with myasthenia gravis: neurological and oncological outcomes

OBJECTIVES

The goal of this study was to analyse the outcomes in 53 patients with thymoma, 34 of whom had myasthenia gravis (MG), who were treated with robotic surgery. The oncological outcomes of the whole series of patients were analysed. Furthermore, because consistent data are not yet available in the literature, the main focus was the analysis of the neurological results of the patients affected by MG and thymoma.

METHODS

The clinical outcomes of 53 patients with a diagnosis of thymoma who underwent robotic thymectomy between January 2014 and December 2019 in our institution were collected and evaluated; 34 of these patients had a concomitant diagnosis of MG. The neurological status of the patients was determined from a clinical evaluation according to the Osserman classification and on pre- and post-surgery Myasthenia Gravis Composite scores, whereas neurological clinical outcomes were assessed using the Myasthenia Gravis Foundation of America Post-Intervention Score. Reduction of steroid therapy was also considered. The recurrence rate, adjuvant radiotherapy and overall survival of the patients with a thymoma were evaluated.

RESULTS

Neurological outcomes: improvement of the clinical conditions was obtained in 26 patients (76.5%) following the operation: complete stable remission was observed in 5 patients (14.7%), pharmacological remission in 10 (29.4%) and minimal manifestation in 11 (32.3%). Four patients (11.8%) exhibited no substantial change from the pretreatment clinical manifestations or reduction in MG medication and 4 (11.8%) patients experienced worsening of clinical conditions. In 21 patients (61.7%) a reduction of the dosage of steroid therapy was obtained. Oncological outcomes: at an average follow-up of 36 months, the overall survival was 96%, 4 patients (7.5%) had pleural relapses and 12 patients (22.6%) underwent postoperative radiotherapy, according to their stage. In accordance with Masaoka staging, 34% were in stage I, 56.6% in stage II and 9.4% in stage III.

CONCLUSIONS

Our results suggest that robotic surgical treatment of patients with thymoma and concomitant MG is effective in improving the neurological outcomes. Moreover, the oncological results obtained in this series confirm the efficacy of robotic surgery for the treatment of thymic malignancies, with results in line with those of open surgery. However, due to the indolent growth of thymomas, further observations with longer follow-up are necessary.

Minimally invasive thymectomy for myasthenia gravis favours left-sided approach and low severity class

OBJECTIVES

Complete thymectomy is a key component of the optimal treatment for myasthenia gravis. Unilateral, minimally invasive approaches are increasingly utilized with debate about the optimal laterality approach. A right-sided approach has a wider field of view, while a left-sided approach accesses potentially more thymic tissue. We aimed to assess the impact of laterality on perioperative and medium-term outcomes, and to identify predictors of a 'good outcome' using standard definitions.

METHODS

We performed a multicentre review of 123 patients who underwent a minimally invasive thymectomy for myasthenia gravis between January 2000 and August 2015, with at least 1-year follow-up. The Myasthenia Gravis Foundation of America standards were followed. A 'good outcome' was defined by complete stable remission/pharmacological remission/minimal manifestations 0, and a 'poor outcome' by minimal manifestations 1-3. Univariate and multivariable logistic regression analyses were performed to assess factors associated with a 'good outcome'.

RESULTS

Ninety-two percent of thymectomies (113/123) were robotic-assisted. The left-sided approach had a shorter median operating time than a right-sided: 143 (interquartile range, IQR 110-196) vs 184 (IQR 133-228) min, P = 0.012. At a median of 44 (IQR 27-75) months, the left-sided approach achieved a 'good outcome' (46%, 31/68) more frequently than the right-sided (22%, 12/55); P = 0.011. Multivariable analysis identified a left-sided approach and Myasthenia Gravis Foundation of America class I/II to be associated with a 'good outcome'.

CONCLUSIONS

A left-sided thymectomy may be preferred over a right-sided approach in patients with myasthenia gravis given the shorter operating times and potential for superior medium-term symptomatic outcomes. A lower severity class is also associated with a 'good outcome'.

Myasthenic Crisis as the First Presentation of Myasthenia Gravis: A Case Report

BACKGROUND Myasthenic crisis is a condition characterized by the sudden onset of myasthenic weakness involving the respiratory muscles and requires ventilatory support to prevent death. This is a case report of respiratory failure in a 43-year-old man as the first presentation of myasthenia gravis. CASE REPORT A 43-year-old man with underlying hypertension and a lacunar stroke with good muscle-power recovery presented with severe community-acquired pneumonia, complicated with respiratory failure requiring invasive ventilatory support. He responded well to the intravenous antibiotic therapy and after 1 week of treatment, he was hemodynamically stable and his septic parameters improved. However, he persistently failed to maintain adequate spontaneous respiratory effort after the removal of the ventilatory support and had to be reintubated multiple times. There was no other identifiable cause for the worsening respiratory failure. He had no clinical features or muscle weakness suggestive of myasthenia gravis. However, his blood test was positive for serum anti-acetylcholine receptor antibodies and repetitive nerve stimulation tests showed the characteristic decremental response of compound muscle action potential amplitude, in keeping with the diagnosis of myasthenia gravis. He responded well to intravenous immunoglobulin and was discharged with anticholinesterase inhibitors and long-term immunosuppression therapy. CONCLUSIONS This report demonstrates that when patients are admitted to the hospital with acute respiratory failure without any underlying pulmonary disease and with weakness of the respiratory muscles, the diagnosis of myasthenia gravis presenting with a myasthenic crisis should be considered.

The morphological basis of the development of the chick embryo immune system

The chick immune system is a fundamental model in basic immunology. In birds, the bone marrow derived pluripotent stem cells after entering the circulation, migrate to bursa of Fabricius to benefit from a microenvironment which supports the differentiation and maturation of B lymphocytes by the help of its resident cells and tissues. Delivering sufficient functional B cells is required to maintain their peripheral population and normal peripheral humoral responses. Additionally, bursa acts as an active site for the generation of antibody diversity through gene conversion. Being consisted of 98% B lymphocytes, the organ is occupied by other cell types including T cells, macrophages, eosinophils and mast cells. Thymus, which is an epithelial organ is the main site of T cell development where positive and negative selections contribute to the development of functional and not autoreactive T cell repertoire. Bursectomy and thymectomy are surgical exercises through which the involvement of cells of specific immunity including B cells and T cells can be determined.