Clinical outcome and predictive factors of postoperative myasthenic crisis in 173 thymomatous myasthenia gravis patients

Myasthenic crisis

Myasthenic crisis (MC) is a life-threatening manifestation of myasthenia gravis (MG) defined by respiratory insufficiency that requires the use of invasive or non-invasive ventilation. This is often the result of respiratory muscle weakness but can also be due to bulbar weakness with upper airway collapse. MC occurs in approximately 15%-20% of patients with MG usually within the first 2 to 3 y of the disease course. Many crises have a specific trigger with respiratory infections being most common; however, no specific trigger is found in 30%-40% of patients. MG patients with a history of MC, severe disease, oropharyngeal weakness, muscle-specific kinase (MuSK) antibodies and thymoma appear to be at higher risk. Most episodes of MC do not occur suddenly, providing a window of opportunity for prevention. Immediate treatment is directed toward airway management and removing any identified triggers. Plasmapheresis is preferred over intravenous immune globulin as the treatments of choice for MC. The majority of patients are able to be weaned from mechanical ventilation within 1 mo and the outcomes of MC are generally favorable. The mortality rate in United States cohorts is less than 5% and mortality in MC seems to be driven by age and other medical co-morbidities. MC does not appear to affect long-term prognosis as many patients are able to eventually achieve good MG control.

Outcomes of Extended Resection for Locally Advanced Thymic Malignancies

BACKGROUND

Thymic malignancies are rare tumors about which data are limited. Our objective here was to evaluate the outcomes and risk factors for complications and death in patients who underwent extended surgery to remove thymic malignancies.

METHODS

We retrospectively included patients who underwent extended resection of locally advanced, nonmetastatic thymic malignancies at our institution. Patients were deemed eligible for resection by a multidisciplinary team. During surgery, priority was given to achieving complete resection rather than to sparing organs.

RESULTS

The 108 patients had a mean age of 53 ± 15 years (range, 9-83); among them, 91 had thymoma, 12 thymic carcinoma, and 5 neuroendocrine tumor. The Masaoka stage was III or higher in 86 patients; examination of operative specimens resulted in downstaging of 22 patients. Tumor-free resection margins were achieved in 98 patients. Overall 5- and 10-year survival rates were 80% and 68%, respectively. Myasthenia gravis, present in 36 patients, was the only independent significant risk factor for major postoperative complications. Age older than 70 years, thymic carcinoma or neuroendocrine tumor, pT3 or pT4 stage, and R1 or R2 resection margins independently predicted death. The number of resected structures was not associated with survival. Thymic carcinoma or neuroendocrine tumor was independently associated with shorter disease-free survival.

CONCLUSION

In an expert center, extended resection targeting complete resection rather than organ preservation provided good outcomes in patients with locally advanced thymic malignancies. The risk/benefit ratio of surgery should be assessed with special care in patients who are elderly or have myasthenia gravis.

Postoperative clinical outcomes of patients with thymic epithelial tumors after over-3-year follow-up at a single-center

BACKGROUND

To evaluate postoperative clinical outcomes and analyze influencing factors for patients with thymic epithelial tumors over 3 years after operation.

METHODS

Patients with thymic epithelial tumors (TETs) who underwent surgical treatment in the Department of Thoracic Surgery at Beijing Hospital from January 2011 to May 2019 were retrospectively enrolled in the study. Basic patient information, clinical, pathological, and perioperative data were collected. Patients were followed up by telephone interviews and outpatient records. Statistical analyses were performed using SPSS version 26.0.

RESULTS

A total of 242 patients (129 men, 113 women) with TETs were included in this study, of which 150 patients (62.0%) were combined with myasthenia gravis (MG) and 92 patients (38.0%) were not. 216 patients were successfully followed up and their complete information was available. The median follow-up period was 70.5 months (range, 2-137 months). The 3-year overall survival (OS) rate of the whole group was 93.9%, and the 5-year OS rate was 91.1%. The 3-year relapse-free survival (RFS) rate of the whole group was 92.2%, and the 5-year relapse-free survival rate was 89.8%. Multivariable COX regression analysis indicated that recurrence of thymoma was an independent risk factor for OS. Younger age, Masaoka-Koga stage III + IV, and TNM stage III + IV were independent risk factors for RFS. Multivariable COX regression analysis indicated that Masaoka-Koga staging III + IV, WHO type B + C were independent risk factors for postoperative improvement of MG. For patients with MG, the postoperative complete stable remission (CSR) rate was 30.5%. And the result of multivariable COX regression analysis showed that thymoma patients with MG with Osserman staging IIA + IIB + III + IV were not prone to achieving CSR. Compared with patients without MG, MG was more likely to develop in patients with WHO classification type B, and patients with myasthenia gravis were younger, with longer operative duration, and more likely to develop perioperative complications.

CONCLUSIONS

The 5-year overall survival rate of patients with TETs was 91.1% in this study. Younger age and advanced stage were independent risk factors for RFS of patients with TETs, and recurrence of thymoma were independent risk factors for OS. In patients with MG, WHO classification type B and advanced stage were independent predictors of poor outcomes of MG treatment after thymectomy.

Risk Factors for Postoperative Myasthenic Crisis After Thymectomy in Patients With Myasthenia Gravis

BACKGROUND

The objective of this study is to characterize postoperative myasthenic crisis (POMC), after extended thymectomy and discuss the treatment options for this condition.

METHODS

Clinical data from patients with generalized myasthenia gravis (MG) who underwent extended thymectomy at Xuanwu Hospital of the Capital Medical University from 2016 to 2018 were reviewed retrospectively. Patients were divided into two groups-POMC and non-POMC. Variables that could potentially predict POMC were analyzed. In the POMC group, the aforementioned variables were compared between patients with and without pneumonia.

RESULTS

Ninety-seven patients were enrolled. Thirty-eight (39.2%) patients developed POMC. The mean duration of mechanical ventilation (MV), length of intensive care unit stay, and duration of hospital stay were significantly longer in the POMC group (P < 0.001). Multivariate logistic regression analysis showed that disease severity, symptom duration longer than 12 mo, and transsternal thymectomy were independent risk factors for POMC. Postoperative pneumonia significantly prolonged the MV period (P = 0.012) and weaning from MV after intravenous immunoglobin (IVIg) treatment (P = 0.005) in POMC patients. Twenty-four (24.7%) POMC patients who received IVIg were successfully weaned from MV and were discharged.

CONCLUSIONS

Disease severity, symptom duration longer than 12 mo, and transsternal thymectomy were independent risk factors for POMC. Postoperative pneumonia worsens the prognosis of POMC.

Thymomatous myasthenia gravis: 10-year experience of a single center

OBJECTIVES

To summarize the clinical features of thymomatous myasthenia gravis (T-MG), examine the association between MG and thymoma, and identify the related factors or predictors for long-term prognosis of T-MG.

METHODS

A retrospective, observational study was conducted on 100 patients with T-MG and 96 patients with non-T-MG (NT-MG) between January 1, 2009 and December 31, 2019. The baseline characteristics were recorded for each patient. Logistic regression was used to measure the association between all clinical variables and T-MG prognosis.

RESULTS

Between the T-MG and NT-MG groups, age at onset (45.66 ± 11.53 years vs 39.06 ± 14.39 years); age >40 years (72.0% vs. 40.6%); AChR-Ab positive rate (100.0% vs. 83.3%); Myasthenia Gravis Foundation of America (MGFA) classification at the worst condition (≥grade III, 61.0% vs. 33.0%); thyroid dysfunction (7.0% vs. 20.8%); and outcome (complete stable remission + pharmacologic remission + improvement, 74.0% vs. 93.7%) were statistically significant (P < .05). Presence of thymoma (OR = 0.196, 95%CI = 0.076-0.511, P = .001) was a risk factor for MG. Male sex, post-operative complications, higher grade of MGFA classification, and thymoma Masaoka-Koga pathological stage were risk predictors for long-term prognosis of T-MG (P < .1). Use of preoperative anticholinesterase drugs (OR = 5.504, 95%CI = 1.424-21.284, P = .013) was identified as an independent predictor for T-MG.

CONCLUSION

T-MG is clinically different from NT-MG, and thymoma is considered a risk factor for MG. Preoperative anticholinesterase drug use is a protective factor for long-term prognosis of T-MG. A comprehensive understanding of the characteristics of T-MG will likely help improve its prognosis.

Assessment of the risks of a myasthenic crisis after thymectomy in patients with myasthenia gravis: a systematic review and meta-analysis of 25 studies

Background

Despite the burgeoning literature describing preoperative and postoperative risks of a myasthenic crisis after thymectomy (MCAT) in patients with myasthenia gravis, substantial differences exist in the risk factors identified by previous studies. We conducted a meta-analysis to assess the reported risk factors and MCAT risk.

Methods

We collected relevant studies on the risk factors for MCAT by searching the PubMed, Embase, The Cochrane Library, China Biology Medicine (CBM), WanFang Data, VIP and CNKI databases. The search period ranged from the establishment of the database to November 2019.

Results

Twenty-five of the 458 identified studies were eligible for the meta-analysis. Seven retrospective cohort studies and 18 case-control studies were included, and 14 risk factors for MCAT were extracted. Meta-analyses of the association between MCAT and risk factors related to the patient’s preoperative condition included a preoperative history of MC, preoperative bulbar symptoms, IIa + IIb + III + VI, IIb + III + VI, VI + V, dosage of pyridostigmine bromide prior to the operation, a preoperative AchR-Ab level > 100 (nm/L), preoperative pulmonary function, preoperative complications, and preoperative disease course. Meta-analyses of the association between MCAT and surgery-related risk factors included intraoperative blood loss > 1000 mL and the mode of operation. Meta-analyses of the association between MCAT and postoperative risk factors included postoperative lung infection, thymoma and the WHO classification. The operation time was not an independent risk factor for MCAT.

Conclusions

The independent risk factors for MCAT were a preoperative history of MC, preoperative bulbar symptoms, preoperative MG Osserman stage, preoperative dosage of pyridostigmine bromide, preoperative serum AchR-Ab level, lung function, major postoperative complications, disease duration before thymectomy, blood loss, thoracotomy, postoperative lung infection, thymoma, and WHO classification.

Surgical outcomes of 215 patients with thymic epithelial tumors: A single-center experience

Objectives

To evaluate the oncological prognosis and neurological outcomes for patients with thymic epithelial tumors (TETs) after thymectomy.

Methods

Consecutive patients with TETs who underwent thymectomy at Beijing Hospital from January 2011 to December 2018 were retrospectively enrolled into the study. Clinical, pathological, and perioperative data was collected. Patients were followed‐up by telephone interview and outpatient records. Statistical analyses were performed using SPSS version 19.0.

Results

A total of 215 patients (115 men and 100 women) were included in this study of which 133 patients (61.9%) had TETs associated with myasthenia gravis (MG), and 82 patients (38.1%) had thymic tumors without MG. A total of 194 (90.2%) patients were successfully followed‐up. The median follow‐up period was 42 months. The five‐year overall survival (OS) rate was 88.6%. MG was the first cause of death for patients with MG (6/10). Prognosis in MG patients was similar to those without MG. Multivariate Cox regression analysis demonstrated that TNM stage III + IV was an independent risk factor for OS. Incomplete resection and younger age were risk factors for tumor recurrence. For patients with MG, the cumulative complete stable remission (CSR) rate increased with the postoperative follow‐up period, and the five‐year CSR rate was 44.7%. Univariate Cox analysis indicated that age, preoperative MG duration and preoperative medication might correlate with CSR. Multivariate Cox analysis only indicated older age as a negative factor of achieving CSR.

Conclusions

MG had little influence on OS and tumor recurrence of thymic tumors. The new TNM staging system was an independent prognostic factor. Incomplete resection and younger age were risk factors for tumor recurrence. Older age was a negative factor of achieving CSR for thymoma patients with MG after extended thymectomy.

Key points

Myasthenic crisis and late deep vein thrombosis following thymectomy in a patient with myasthenia gravis: A case report

INTRODUCTION

Surgical stress and pain are potential provoking factors for postoperative myasthenic crisis (POMC). We report the occurrence of early POMC and late deep vein thrombosis (DVT) in a man with myasthenia gravis (MG) undergoing thymectomy, addressing possible link between reversal of opioid overdose with naloxone and the triggering of POMC.

PATIENT CONCERNS

A 71-year-old man with impaired renal function (ie, estimated glomerular filtration rate [egfr]: 49.1 mL/min/1.73 m) with diagnosis of MG made 2 months ago was scheduled for thymectomy. After uncomplicated surgery, he experienced opioid overdose that was treated with naloxone. Hyperlactatemia then developed with a concomitant episode of hypertension. Three hours after reversal, he suffered from myasthenic crisis presenting with respiratory failure and difficult weaning from mechanical ventilation.

DIAGNOSIS

Stress-induced hyperlactatemia and subsequent myasthenic crisis INTERVENTIONS:: Pyridostigmine and immunosuppressive therapy with prednisolone were initiated. Hyperlactatemia subsided on postoperative day (POD) 5. Tracheal extubation was performed successfully on POD 6.

OUTCOMES

During the course of hospitalization, his eGFR (ie, 88.9 mL/min/1.73 m) was found to improve postoperatively. After discharge from hospital, he developed DVT in the left femoral and popliteal veins on POD 24 when he was readmitted for immediate treatment with low-molecular-weight heparin. He was discharged without sequelae on POD 31. There was no recurrence of myasthenic crisis or DVT at 3-month follow-up.

CONCLUSIONS

Following naloxone administration, hyperlactatemia may be an indicator of pain-related stress response, which is a potential provoking factor for myasthenic crisis. Additionally, patients with MG may have an increased risk of DVT possibly attributable to immune-mediated inflammation. These findings highlight the importance of perioperative avoidance of provoking factors including monitoring of stress-induced elevations in serum lactate concentration, close postoperative surveying for myasthenic crisis, and early recognition of possible thromboembolic complications in this patient population.

Surgical effect and prognostic factors of myasthenia gravis with thymomas

Background

To evaluate the surgical effect and prognostic factors of extended thymectomy for myasthenia gravis (MG) patients with thymomas.

Methods

Patients with MG with thymomas who underwent extended thymectomy at Peking University People's Hospital and Beijing Hospital between January 2010 and December 2018 were retrospectively enrolled. Patients were followed up by telephone or outpatient record review . Statistical analyses were performed using SPSS version 19.0.

Results

A total of 194 patients were included in this study. According to the Osserman classification, there were 56 type I, 52 type IIa, 67 type IIb, 14 type III, and five type IV. Video‐assisted thoracoscopic surgery (VATS) thymectomies were performed in 137 patients, and transthymectomies in 57 patients. The average operation time was 136.6 ± 46.5 minutes, average blood loss was 129.3 ± 287.4 mL, and average postoperative stay was 8.3 ± 7.4 days. A total of 170 patients (87.6%) were successfully followed up. The median follow‐up period was 45 months, and the five‐year overall survival (OS) rate was 81.9%. Cox regression analysis demonstrated that age, Masaoka stage, and recurrence were prognostic factors of OS. Tumor recurrence tended to occur in patients with Masaoka stage III + IV, and age was a protective factor. A total of 20 patients experienced postoperative myasthenic crisis (POMC). Univariate analysis indicated that presence of bulbar symptoms, surgical procedure, and blood loss were risk factors for POMC, but multivariate analysis only indicated the presence of bulbar symptoms as an independent risk factor. A total of 162 patients were evaluated for post intervention MG status. A total of 55 patients achieved complete stable remission; the overall effective rate was 84.5%. Older patients and those with B‐type thymomas had a lower probability of achieving complete stable remission. Efficacy was similar in patients who underwent VATS or the transsternal procedure.

Conclusions

Age, Masaoka stage, and recurrence were prognostic factors of OS. Presence of bulbar symptoms was an independent risk factor for POMC. Age and World Health Organization classification influence the postoperative effect of MG.

Key points

Significant findings of the study

Age, Masaoka stage, and recurrence were prognostic factors of OS for MG with thymomas. The presence of bulbar symptoms was an independent risk factor for POMC. Age and World Health Organization classification may influence the postoperative effect of MG.

What this study adds

Our study had a relatively large sample size of MG patients with thymomas only. We emphasize the analysis of the postoperative effect of MG and overall survival for these patients, which is a complement to previous studies.

Risk factors of myasthenia crisis after thymectomy among myasthenia gravis patients: A meta-analysis

BACKGROUND

The purpose of the study was to determine the risk factors of post-surgery myasthenia crisis (PMC) among myasthenia gravis (MG) patients.

METHODS

A meta-analysis to synthesize all eligible literatures was conducted to analyze PMC predictors among MG patients.

RESULTS

A total of 15 trials with 2626 patients were included for the meta-analysis. As a result, patients with history of MC (RR = 3.36, 95%CI: 2.46-4.59, P < .001), generalized MG (RR = 0.39, 95%CI: 0.26-0.59, P < .001), bulbar symptom (RR = 3.59,95%CI:2.53-5.09, P < .001), thymoma (RR = 2.10, 95%CI:1.37-3.21, P = .001), post-surgery morbidity presence(RR = 2.59, 95%CI:1.90-3.54, P < .001), high-dose pyridostigmine usage (SMD = 0.480, 95%CI: 0.35-0.61 P < .001) tended to develop PMC. Large dose of steroid may reduce the incidence of PMC (RR = 0.41 95%CI: 0.18-0.94, P = .036). Regular steroid use (P = .066), immunosuppressive therapy (P = .179), gender (P = .774), and age at thymectomy (P = .212) had no impact upon PMC development.

CONCLUSION

History of PMC, thymoma, generalized MG, bulbar symptom, and concomitant complication are the risk factors of PMC.

Prognostic Analysis of Thymoma-Associated Myasthenia Gravis (MG) in Chinese Patients and Its Implication of MG Management: Experiences from a Tertiary Hospital

BACKGROUND

Myasthenia gravis (MG) is an autoantibody-mediated neuromuscular disorder. Approximately 10-20% of all MG patients experience thymoma (benign tumor arising from thymus tissue). Thymectomy has been the standard of care for thymomatous myasthenia gravis (TMG). However, the clinical outcome of TMG after thymectomy has not been sufficiently studied, especially the long-term prognosis. Therefore, the aim of this study was to analyze the clinical characteristics contributing to the prognostic factors of TMG.

METHODS

We reviewed 70 TMG patients in the Xiangya Hospital and classified them into the minimal manifestation (MM) group and No MM group, according to the long-term treatment outcome. MM-or-better status was defined as the goal treatment for TMG patients. We collected and analyzed the demographic data, the WHO classification of thymoma, MG-associated antibody levels, disease severity, treatment-related data as well as clinical outcome at six months. Variables selected by univariate analysis were used in the multivariate logistic regression model to identify the prognostic factors.

RESULTS

The differences in clinical outcome at six months and worst QMGS were significant, while the differences in other factors were insignificant between groups. Clinical outcome at six months (OR=23.5 95% CI 2.4-231.5, P=0.007) and dyspnea before thymectomy (OR=0.2, 95% CI 0.03-0.75, P=0.021) were identified as the prognostic factors of long-term treatment.

CONCLUSION

Demographic and clinical features were similar in TMG patients treated at our hospital. The early achievement of MM-or-better status may indicate a good outcome in the long term. Dyspnea before thymectomy appears to associate with a poor prognosis.

Myasthenia Gravis and Thymoma Surgery: A Clinical Update for the Cardiothoracic Anesthesiologist

Myasthenia gravis (MG) is a rare neuromuscular disorder characterized by skeletal muscle weakness. Patients with MG who have thymoma and thymic hyperplasia have indications for thymectomy. The perioperative care of patients with MG scheduled for thymus resection should be focused on optimizing their neuromuscular function, identifying factors related to postoperative mechanical ventilation, and avoiding of triggers associated with myasthenic or cholinergic crisis. Minimally invasive surgical techniques, use of regional analgesia, and avoidance or judicious administration of neuromuscular blocking drugs (NMBs) is recommended during the perioperative period. If NMBs are used, sugammadex appears to be the drug of choice to restore adequately the neuromuscular transmission. In patients with postoperative myasthenic crisis, plasma exchange or intravenous immune globulin and mechanical support is recommended.