Transcervical thymectomy for myasthenia gravis achieves results comparable to thymectomy by sternotomy

Myasthenia Gravis with Toxic Goiter: Challenges with Management in a Low-Resource Setting in Africa; Review of Literature and Case Report

ABSTRACT

Myasthenia gravis (MG) is an antibody-mediated autoimmune disease with the cardinal feature being exertional voluntary skeletal muscle weakness and fatigability. It can be an isolated finding or in association with other autoimmune conditions such as Hashimoto's thyroiditis, Graves' disease, systemic lupus erythematosus (SLE), or rheumatoid arthritis. Thymectomy is recommended for most patients with MG whose symptoms begin before the age of 60 years. Patients with thymoma or thymic hyperplasia do respond to thymectomy compared to those without thymoma or enlarged thymus. Those with enlarged goiter would benefit from thyroidectomy. The management of these patients requires a multidisciplinary approach as performed in a low-resource setting. We are reporting the case of a 24-year-old who presented with MG with toxic goiter and had good control on medication. A computed tomography scan of the chest showed a superior mediastinal mass and a soft tissue scan of the neck was done which showed a diffusely enlarged thyroid gland. She subsequently had thymectomy and subtotal thyroidectomy with a satisfactory outcome. We highlight this case to show that MG with thymoma and goiter could coexist. Reports of such findings are infrequently reported in our environment.

The impact of thymectomy in subgroups of Myasthenia gravis patients: a single center longitudinal observation

BACKGROUND

Myasthenia gravis (MG) is a rare neuromuscular disorder. Symptoms can range from ptosis only to life threatening myasthenic crisis. Thymectomy is recommended for anti-acetylcholine receptor-antibody positive patients with early-onset MG. Here, we investigated prognostic factors shaping therapeutic outcomes of thymectomy to improve patient stratification.

METHODS

We retrospectively collected single-center data from a specialized center for MG from all consecutive adult patients that underwent thymectomy from 01/2012 to 12/2020. We selected patients with thymoma-associated and non-thymomatous MG for further investigations. We analyzed the patient collective regarding perioperative parameters in relation to the surgical approach. Furthermore, we investigated the dynamics of the anti-acetylcholine receptor-antibody titers and concurrent immunosuppressive therapies, as well as the therapeutic outcomes in dependence of clinical classifications.

RESULTS

Of 137 patients 94 were included for further analysis. We used a minimally invasive approach in 73 patients, whereas 21 patients underwent sternotomy. A total of 45 patients were classified as early-onset MG (EOMG), 28 as late-onset MG (LOMG) and 21 as thymoma-associated MG (TAMG). The groups differed in terms of age at diagnosis (EOMG: 31.1 ± 12.2 years; LOMG: 59.8 ± 13.7 years; TAMG: 58.6 ± 16.7 years; p < 0.001). Patients with EOMG and TAMG were more often female than patients in the LOMG group (EOMG: 75.6%; LOMG: 42.9%; TAMG: 61.9%; p = 0.018). There were no significant differences in outcome scores (quantitative MG; MG activities of daily living; MG Quality of Live) with a median follow-up of 46 months. However, Complete Stable Remission was achieved significantly more frequently in the EOMG group than in the other two groups (p = 0.031). At the same time, symptoms seem to improve similarly in all three groups (p = 0.25).

CONCLUSION

Our study confirms the benefit of thymectomy in the therapy of MG. Both, the concentration of acetylcholine receptor antibodies and the necessary dosage of cortisone therapy show a continuous regression after thymectomy in the overall cohort. Beyond EOMG, groups of LOMG and thymomatous MG responded to thymectomy as well, but therapy success was less pronounced and delayed compared to the EOMG subgroup. Thymectomy is a mainstay of MG therapy to be considered in all subgroups of MG patients investigated.

[The value of thymectomy in the treatment of non-thymomatous myasthenia gravis]

The value of thymectomy in the treatment of non-thymomatous myasthenia gravis has been controversially discussed. The relatively low incidence and prevalence of this disease, the inconsistent documentation in various studies and the necessity of a long-term follow-up to assess the therapeutic effects has made the generation of valid data difficult. The publication in 2016 of the MGTX trial in the New England Journal of Medicine delivered the first randomized controlled data in which patients aged 18-65 years with generalized myasthenia gravis and positive for acetylcholine receptor antibodies showed a significant benefit after surgical resection of the thymus via median sternotomy. Despite a lack of validation of the advantages of thymectomy by minimally invasive surgery from randomized controlled studies, this technique seems to positively influence the outcome of certain patient groups in a similar way. Video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracic surgery (RATS) using subxyphoidal and transcervical access routes showed not only esthetic advantages but also showed no relevant inferiority in the influence on clinical outcomes of myasthenia gravis compared to median sternotomy; however, not only the benefits and the esthetic results show differences but also the advantages in the various subtypes of myasthenia gravis show divergent prospects of success with respect to remission. The clinical spectrum of myasthenia is heterogeneous with respect to the occurrence of antibodies, the body region affected and the age of the patient at first diagnosis. Ultimately, thymectomy is an effective causal treatment of myasthenia gravis.

Outcomes After Transcervical Thymectomy for Ocular Myasthenia Gravis: A Retrospective Cohort Study With Inverse Probability Weighting

BACKGROUND

The benefit of thymectomy in reducing requirement for corticosteroids, symptom severity, need for immunosuppression, and hospitalization rates in patients with seropositive generalized myasthenia has recently been established. It is unclear whether this benefit applies to patients with myasthenia and purely ocular manifestations (ocular myasthenia gravis [OMG]).

METHODS

We conducted a retrospective single-center cohort study of patients with OMG. Patients were included if their diagnosis was confirmed by acetylcholine receptor or muscle-specific kinase antibodies, abnormal electrophysiology, or a positive edrophonium test and at least 1 year of clinical follow-up. At each visit, the presence and severity of ocular and generalized symptoms was ascertained using a 4-point scale. Prednisone dose, steroid-sparing agent use, and need for intravenous immunoglobulin or plasmapheresis were recorded. The effect of thymectomy on time-weighted prednisone dose and symptom severity score was assessed using linear regression models. To adjust for nonrandomization of thymectomy, we used inverse probability weighting using a propensity score model derived from the prethymectomy observation period for thymectomy patients and a 6-month lead-in period for nonthymectomy patients that incorporated age, sex, acetylcholine receptor antibody seropositivity, disease severity (as defined by both symptom severity and treatment requirement), and treating physician preferences.

RESULTS

Eighty-two patients (30 with thymectomy and 52 nonthymectomy) were included. In unadjusted analyses, time-weighted daily prednisone dose was 2.9 mg higher with thymectomy compared with nonthymectomy (95% CI: 0.2-5.7), but after inverse probability weighting, this was no longer statistically significant (difference = 1.7 mg, 95% CI: -0.8 to 4.2). There was no statistically significant difference in symptom severity score (adjusted difference = 0.35, 95% CI: -0.02 to 0.72) or risk of generalization (P = 0.22).

CONCLUSIONS

In this retrospective study that used statistical techniques to account for nonrandomization, no significant differences in prednisone dose or symptom severity after thymectomy in ocular myasthenia were demonstrated.

Prevalence and risk factors of myasthenia gravis recurrence post-thymectomy

Objectives:

To evaluate the prevalence and the factors associated with recurrence of myasthenia gravis following thymectomy.

Methods:

Six electronic databases which reported on recurrence of myasthenia gravis following thymectomy and/or its risk factors from 1985 to 2018 were searched. Summary prevalence and risk values obtained based on the random effect models were reported.

Results:

Seventy (70) papers containing 7,287 individuals with myasthenia gravis who received thymectomy as part of their management were retrieved. The patients had a mean follow-up of 4.65 years post-thymectomy. The prevalence of myasthenia gravis recurrence post-thymectomy was 18.0% (95% CI 14.7–22.0%; 1865/7287). Evident heterogeneity was observed (I²=93.6%; p<0.001). Recurrence rate was insignificantly higher in male compared with female patients (31.3 vs. 23.8%; p=0.104). Pooled recurrence rates for thymomatous (33.3%) was higher than the rate among non-thymomatous (20.8%) myasthenia gravis patients (Q=4.19, p=0.041). Risk factors for recurrence include older age, male sex, disease severity, having thymomatous myasthenia gravis, longer duration of the myasthenia gravis before surgery, and having an ectopic thymic tissue.

Conclusion:

A fifth of individuals with myasthenia gravis experience recurrence after thymectomy. Closer monitoring should be given to at-risk patients and further studies are needed to understand interventions to address these risks.

International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update

Objective

To update the 2016 formal consensus-based guidance for the management of myasthenia gravis (MG) based on the latest evidence in the literature.

Methods

In October 2013, the Myasthenia Gravis Foundation of America appointed a Task Force to develop treatment guidance for MG, and a panel of 15 international experts was convened. The RAND/UCLA appropriateness method was used to develop consensus recommendations pertaining to 7 treatment topics. In February 2019, the international panel was reconvened with the addition of one member to represent South America. All previous recommendations were reviewed for currency, and new consensus recommendations were developed on topics that required inclusion or updates based on the recent literature. Up to 3 rounds of anonymous e-mail votes were used to reach consensus, with modifications to recommendations between rounds based on the panel input. A simple majority vote (80% of panel members voting “yes”) was used to approve minor changes in grammar and syntax to improve clarity.

Results

The previous recommendations for thymectomy were updated. New recommendations were developed for the use of rituximab, eculizumab, and methotrexate as well as for the following topics: early immunosuppression in ocular MG and MG associated with immune checkpoint inhibitor treatment.

Conclusion

This updated formal consensus guidance of international MG experts, based on new evidence, provides recommendations to clinicians caring for patients with MG worldwide.

Minimal Access Surgery for Thymoma

Thymoma is a rare epithelial tumor of the thymus gland. Despite rarity, it is the most common tumor of the anterior mediastinum. Surgical resection in the form of extended thymectomy is the gold standard operation. Conventionally and even in the current era of significant advances in the minimally invasive surgery, open transsternal extended thymectomy is considered the gold standard, particularly for advanced-stage tumors. There is however significant evidence now available for the use of minimally invasive approaches for early-stage thymomas. This article aims to discuss the various minimally invasive approaches currently being employed for thymomas.

Thymectomy in Non-Thymomatous Myasthenia Gravis: Does An RCT Solve The 75-Year-Old Controversy?

The role of thymectomy in thymomatous myasthenia gravis (MG) is unambiguous. However, its role in non-thymomatous MG (NTMG) remains debatable. The evidence till date is not robust. In this short review, we try to see the pros and cons of thymectomy in NTMG and critically appraise the evidence available till date.

Unraveling the role of ectopic thymic tissue in patients undergoing thymectomy for myasthenia gravis

Extended thymectomy has been considered the goal of surgery for myasthenia gravis (MG) mainly due to the existence of ectopic thymic tissue. Recently, ectopic thymic tissue has attracted increasing attention in patients with MG following thymectomy. However, the specific role of ectopic thymic tissue in patients with MG is still under debate. A systematic search of the literature was performed on PubMed and Medline according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISM) statement. Studies evaluating the rate of ectopic thymic tissue in patients with MG with or without thymoma were included. Extraction was performed for all eligible studies and the rate of ectopic thymic tissue at common locations was calculated. Eighteen out of fifty-nine studies were eligible for inclusion, of which ten studies reported the common locations of ectopic thymic tissue in mediastinal fat. Of these ten studies, the presence of ectopic thymic tissue was investigated in different anatomical locations in 882 patients, of whom, 509 patients (58%) have at least one positive location with the most common ones being anterior mediastinal fat, pericardiophrenic angles, aortopulmonary window, cervical region (pretracheal fat) and lateral to phrenic nerves. On the other hand, nine studies analyzed the influence of the presence of ectopic thymic tissue on the clinical outcomes of MG patients. Of these, six found that the presence of ectopic thymic tissue in MG patients is a significant predictor of poor outcome after thymectomy, however, the other three did not find a significance. Altogether, ectopic thymic tissue is likely to present in more than a half of patients undergoing thymectomy for MG. Besides, MG patients who have ectopic thymic tissue after thymectomy do not seem to have as good outcome as those who have not.

Non-Myasthenia Gravis Immune Syndromes and the Thymus: Is There a Role for Thymectomy?

Thymectomy has long been considered, performed, and discussed for many different nonmyasthenic immune syndromes. Thymectomy is now an established treatment for MG, and has been performed for other immune syndromes with varying degrees of improvement. Although numerous reports document immune syndromes' association with thymoma, few address the role of thymectomy in symptom resolution. This review assesses thymectomy in the various nonmyasthenic immune syndromes for which it has been tried. Based on this review, it seems appropriate to revisit a more active role for thymectomy in pure red cell aplasia, pemphigus, rheumatoid arthritis, autoimmune hemolytic anemia, and ulcerative colitis.

A Neurologist's Perspective on Thymectomy for Myasthenia Gravis: Current Perspective and Future Trials

The first randomized blinded study of thymectomy in nonthymomatous myasthenia gravis was designed to answer 3 questions: does the combination of prednisone and removal of the thymus gland via extended transsternal thymectomy after 3 years compared with an identical dosing protocol of prednisone alone (1) lead to better disease status for generalized MG patients with antiacetylcholine receptor antibodies, (2) reduce their prednisone requirements, and/or (3) reduce the side-effect burden from medications used to treat the disease? The study demonstrated that thymectomy confers these benefits for patients and sets the stage for inquiries into the benefits of less-invasive approaches to thymic resection.

Thoracoscopic thymectomy - The method of choise in surgical treatment of non-invasive thymomas

Background

Thymomas are very rare malignances, with an estimated incidence of 0.15 cases per 100.000. Metastases of Thymoma are usually involved the pleura, pericardium or diaphragm, whereas the probability of extrathoracic metastases are extremely low. Success in the treatment of thymomas mainly depends on the radicalism of the performed operation.

Materials and methods

Since 2008 33 Thoracoscopic Thymectomies were performed in the thoracic department of the N.N.Blokhin Russian Cancer Research Center. The right-sided approach was in 23 (69,7%) patients, 7 (21,2%) operated on the left and 3 (9,1%) patients had combined approach. We include 26 patients with similar characteristics of the primary tumor operated from sternotomy approach to compare direct and long-term results of surgical treatment.

Results

Thoracoscopic approach in comparison with sternotomy in surgical treatment of non-invasive Thymomas significantly reduces the incidence of postoperative therapeutic complications (p < 0.01). There was a decrease in the frequency of postoperative surgical complications (p = 0.08).

Conclusion

Thoracoscopic thymectomy in comparison with thymectomy from open surgical approach contributes to a significant decrease in the length of patients' stay in the intensive care unit and hospital, and the duration of analgesia with narcotic analgesics in the postoperative period. All of the above factors contribute to shorter periods of functional recovery of patients and a full return to a normal lifestyle.

Update on ocular myasthenia gravis in Taiwan

Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Autoantibodies to the acetylcholine receptor or, less frequently, to muscle-specific kinase, attack against the postsynaptic junctional proteins, resulting in fluctuating and variable weakness of muscles. Extraocular, levator palpebrae superioris, and orbicularis oculi muscles are particularly susceptible. The majority of patients with MG present with purely ocular symptoms including ptosis and diplopia initially. About half of these patients progress to generalized disease within 2 years. The prevalence of MG in Taiwan is 140 per million with male to female ratio of 0.7. The incidence rate is higher in the elderly. Several immune-related diseases such as lymphoid malignancy, diabetes, and thyroid diseases are associated with MG in the national population-based studies in Taiwan. Ice pack test, rest test, Tensilon/neostigmine test, circulating antibody measurement, and electrophysiological studies are useful diagnostic tools with variable sensitivity and specificity. For the patients with ocular MG, acetylcholinesterase inhibitors are usually the first-line treatment. Corticosteroids and immunosuppressant could provide better disease control and may reduce the risk of conversion to generalized form although there is still some controversy. A thymectomy is also beneficial for ocular MG, especially in refractory cases. The correction of ptosis and strabismus surgery could improve the visual outcome but should be performed only in stable disease.

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.

First-in-Man Transcervical Surgical Aortic Valve Replacement Using the CoreVista System

OBJECTIVE

This study aimed to evaluate a novel device system for surgical aortic valve replacement (SAVR) using a unique new less invasive access approach. The hypothesis is that SAVR can be performed through a short transverse incision in the neck, similar to that used for transcervical thymectomy avoiding chest disruption.

METHODS

A new device system was developed to provide retraction, step-by-step illumination, and on-screen visualization for the new approach. Preliminary feasibility studies were performed in cadavers. Comprehensive risk analysis was performed, and training was implemented in Thiel preserved cadavers. For the first-in-man clinical case, a 63-year-old woman with symptomatic critical aortic stenosis (The Society of Thoracic Surgeons risk, 11%) and heavily calcified aortic valve was selected. A short transverse incision was made in the neck; the device was introduced, and the sternum was elevated; femorofemoral cardiopulmonary bypass was established; substernal dissection was guided by the sequenced illumination, and high-definition visualization was provided by the device, allowing for optimal exposition of the aorta and aortic valve; and a 23-mm Medtronic ENABLE sutureless valve prosthesis was implanted. Procedure success was evaluated according to the standardized composite end point definition of "device success" proposed by the Valve Academic Research Consortium.

RESULTS

Access, delivery, and deployment of the valve prosthesis were successful. The correct position and intended performance of the valve were demonstrated (mean gradient, 6 mm Hg; aortic valve area, 2.5 cm) with the absence of moderate or severe prosthetic aortic regurgitation. Only one valve prosthesis was used.

CONCLUSIONS

Transcervical SAVR with sutureless valve is feasible using this novel access system. The new approach has potential to offer patients substantially shorter stay and fewer, less serious complications, as has been observed in transcervical thymectomy. Further studies are merited.

Thymectomy in Myasthenia Gravis

In recent years, thymectomy has become a widespread procedure in the treatment of myasthenia gravis (MG). Likelihood of remission was highest in preoperative mild disease classification (Osserman classification 1, 2A). In absence of thymoma or hyperplasia, there was no relationship between age and gender in remission with thymectomy. In MG treatment, randomized trials that compare conservative treatment with thymectomy have started, recently. As with non-randomized trials, remission with thymectomy in MG treatment was better than conservative treatment with only medication. There are four major methods for the surgical approach: transcervical, minimally invasive, transsternal, and combined transcervical transsternal thymectomy. Transsternal approach with thymectomy is the accepted standard surgical approach for many years. In recent years, the incidence of thymectomy has been increasing with minimally invasive techniques using thoracoscopic and robotic methods. There are not any randomized, controlled studies which are comparing surgical techniques. However, when comparing non-randomized trials, it is seen that minimally invasive thymectomy approaches give similar results to more aggressive approaches.

Randomized Trial of Thymectomy in Myasthenia Gravis

BACKGROUND

Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone.

METHODS

We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period.

RESULTS

A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003).

CONCLUSIONS

Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

Predictors of Outcome for Myasthenia Gravis after Thymectomy

The aim of this study was to assess the clinical outcome of patients with myasthenia gravis treated with maximal thymectomy and to identify prognostic variables that predict the outcome. Over 15 years, from 1986 to 2001, we collected data on 100 patients with myasthenia gravis who underwent maximal thymectomy and retrospectively reviewed their outcome. Women comprised 63% and the median age was 25 years (range, 4 to 61). The median duration of the disease was 26 months (range, 1 to 240). According to the Osserman classification, there were seven patients in class I, 31 in class II, 47 in class III, and 15 in class IV. In non thymomatous patients (93 patients), complete remission rate progressively increased from 37.4% to 58.2% and 75% at 3, 10 and 15 years of follow-up respectively. These findings suggest that the complete remission rate is prone to increase with time after maximal thymectomy. The total benefit rate achieved was estimated to be 86% while 14% did not improve at a mean follow-up period of 7.6 years (range, 8 to 180 months). Univariate analysis ( p < 0.05) showed that age, thymic histology and ectopic thymic tissue are significant prognostic factors for outcome.

Eight-year follow-up of patients with myasthenia gravis after thymectomy

PURPOSE

To depict the long-term outcome of patients with myasthenia gravis after thymectomy in combination with immunotherapy, and the factors that may potentially affect the outcome.

METHODS

The 306 patients with myasthenia gravis who underwent extended thymectomy from January 1984 to December 2011 at Tongji Hospital were retrospectively evaluated.

RESULTS

The patients consisted of 174 cases with thymoma and 132 cases without thymoma. Pharmaceutical treatment was tailored for each case during follow-up. Nine patients with thymomatous myasthenia gravis died during the perioperative period, and 297 patients were followed for 8.6 years. By their latest visits, 241 patients (81.1%) gained satisfactory efficacy, 24 cases died (8.1%), and 32 cases (10.8%) remained unchanged or deteriorated. Favorable factors for satisfactory efficacy included the presence of ocular myasthenia gravis before operation, no presence of thymoma, and lack of concomitant diseases. It is interesting to mention that, patients with non-thymomatous myasthenia gravis obtained significantly higher rates of complete stable remission and clinical remission than the patients with thymomatous myasthenia gravis.

CONCLUSIONS

Extended thymectomy combined with immunotherapy is a preferred treatment with a satisfactory long-term remission rate. Patients with non-thymomatous myasthenia gravis have a much more promising prognosis than the patients with thymomatous myasthenia gravis. However, appropriate caution must be taken to discontinue pharmaceutical therapy as relapse remains a major concern after a patient who has already undergone thymectomy becomes symptom-free.

The myasthenic patient in crisis: an update of the management in Neurointensive Care Unit

Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular transmission leading to generalized or localized muscle weakness due most frequently to the presence of autoantibodies against acetylcholine receptors in the postsynaptic motor end-plate. Myasthenic crisis (MC) is a complication of MG characterized by worsening muscle weakness, resulting in respiratory failure that requires intubation and mechanical ventilation. It also includes postsurgical patients, in whom exacerbation of muscle weakness from MG causes a delay in extubation. MC is a very important, serious, and reversible neurological emergency that affects 20-30% of the myasthenic patients, usually within the first year of illness and maybe the debut form of the disease. Most patients have a predisposing factor that triggers the crisis, generally an infection of the respiratory tract. Immunoglobulins, plasma exchange, and steroids are the cornerstones of immunotherapy. Today with the modern neurocritical care, mortality rate of MC is less than 5%.

Thoracoscopic thymectomy: technical pearls to a 21st century approach

PURPOSE

Thoracoscopic approaches to thymectomy have increased as imaging and instrumentation have advanced. Indications for the thoracoscopic approach are evolving. We reviewed our experience in the transition from sternotomy to thoracoscopy and have gleaned technical points to aid in performing thymectomy.

METHODS

The experience during the transition of sternotomy to thoracoscopy was reviewed.

RESULTS

THE FOLLOWING COMPONENTS HAVE BEEN OBSERVED TO BE ADVANTAGEOUS: (I) initial patient positioning is crucial; (II) thoracoscopy provides improved visualization (a separate camera setup can facilitate visualization of the left phrenic nerve); (III) CO2 aids in dissection; (IV) electrocautery and harmonic scalpel aid in dissection and hemostasis; (V) circumferential dissection identifies anatomic boundaries; (VI) endoscopic ligation of innominate vein branches is adequate; and (VII) minimal access techniques impart a shorter convalescence. In our transition, the length of stay has decreased from 4.3±2.9 to 2.3±1.2 days (P=0.0217).

CONCLUSIONS

We are routinely able to employ this thoracoscopic approach for complete removal of thymic tissue in patients with myasthenia gravis and those with small (<3 cm) thymic masses. A standard approach to dissection in thoracoscopic thymectomy streamlines the procedure and enables safe resection.

Single-institution experience on robot-assisted thoracoscopic operations for mediastinal diseases

OBJECTIVE

: After the introduction of video-assisted thoracoscopic surgery 20 years ago, the minimally invasive techniques in thoracic surgery have found a growing application. The recent introduction of robotic technology has increased the potentiality of thoracoscopic technique leading to an expansion of indications and applications, particularly for the management of mediastinal diseases. We reviewed our experience in robot-assisted thoracoscopic resection of benign and malignant mediastinal diseases.

METHODS

: Between 2002 and 2010, 108 patients (79 women and 29 men; median age 38 y) underwent robot-assisted thoracoscopy using the "da Vinci" robotic system for several mediastinal diseases. There were 100 thymectomies, 3 resections of paravertebral tumors, 1 thymic cyst, 1 ectopic goitre, 1 ectopic mediastinal parathyroidectomy, 1 thymic carcinoid, and 1 foregut cyst. Ninety-five (87.9%) patients were affected by myasthenia gravis.

RESULTS

: All procedures were completed successfully using the da Vinci robot; no open conversions were required, but in three (2.8%) cases, a fourth access was added. There was no surgical mortality; four (3.6%) patients had postoperative complications (two hemothorax, one chylothorax, and one fever) treated conservatively. Median operation time was 120 (range 60-300) minutes and median hospitalization was 3 (range 2-14) days. Global benefit rate for patients with myasthenia gravis reached the value of 93.4% with progressive improvement over years.

CONCLUSIONS

: Several mediastinal operations may be feasible by using a robot-aided thoracoscopic approach. The technical innovations offered by robotic instrumentation make all procedures safer and easier when compared with standard thoracoscopic approach, with particular reference for application in mediastinal field.

Factors predicting surgical outcome of thymectomy in myasthenia gravis: A 16-year experience

Aim:

To assess the surgical outcome of myasthenia gravis (MG) following thymectomy and to determine the outcome predictors to such therapeutic approach.

Materials and Methods:

This study is a retrospective review of 80 consecutive thymectomies performed for MG over a 16-year period.

Results:

There were 41 females and 39 males (mean age, 34.32 years) with mean disease duration of 17.45 months prior to surgery. Stagewise distribution of the patients revealed 2.5% in stage I, 48.7% in stage IIA, 33.8% in stage IIB, 8.7% in stage III, and 6.3% in stage IV. The surgical approach was either trans-sternal (n=67) or video-assisted thoracoscopic route (n=13). Follow-up was obtained in 91.2% (n=73) of patients with mean duration of 67.7 months. At their last follow-up, 26.0% were in complete remission, 35.6% were asymptomatic on decreased medications, and 17.8% had clinical improvement on decreased medications. Overall, 79.4% of patients benefited from surgery, 8.2% had unchanged disease status, and 12.3% worsened clinically. Factors influencing favorable outcome include sex, disease stage, gland weight, and preoperative medication with anti-cholinesterase (P<0.05). There was one death in the perioperative period due to septicemia. Two patients died at fourth and seventh month following thymectomy.

Conclusion:

Thymectomy for MG is safe and effective. Certain influencing factors may shape treatment decisions and target higher risk patients.

Intravenous flurbiprofen for post-thymectomy pain relief in patients with myasthenia gravis

Background

Post-thymectomy pain in myasthenia gravis (MG) patients can inhibit breathing and coughing. Inappropriate usage of analgesics may exacerbate respiratory inhibition and even cause myasthenic crisis. Flurbiprofen is a non-steroidal anti-inflammatory drug (NSAID) that is commonly used to control moderate postoperative pain and is not associated with respiratory inhibition. We hypothesized that flurbiprofen may provide post-thymectomy pain relief without increasing the risk of complications in MG patients.

Methods

Two hundred MG patients underwent extended thymectomy from March 2006 to December 2010 and were randomly allocated to a flurbiprofen group (110 patients, 50 mg intravenous flurbiprofen axetil) or a control group (90 patients, 100 mg intramuscular tramadol) as postoperative analgesia. Visual analog scale (VAS) pain score, heart rate, blood pressure, respiratory rate, pulse oximetry (SpO₂), and adverse effects were recorded before and up to 24 h after drug administration.

Results

There were no significant differences in the preoperative clinical characteristics of the flurbiprofen and control (tramadol) groups. Both flurbiprofen and tramadol significantly alleviated post-thymectomy pain (p < 0.05 for both), but patients in flurbiprofen group had significantly lower VAS pain scores at 0.5 h, 2 h, 4 h, and 8 h after surgery (p < 0.05 for all times). There were no significant post-thymectomy changes of heart rate, respiratory rate, mean arterial blood pressure, or SpO₂ in either group at all time points.

Conclusions

Post-thymectomy intravenous administration of flurbiprofen axetil provides safe and effective analgesia for MG patients.

Can invasive thymomas be resected by video-assisted thoracoscopic surgery?

Although video-assisted thoracic surgery can be used for well-encapsulated thymomas, its role in invasive thymomas remains controversial. Between 1998 and 2009, 77 patients aged 22-76 years underwent thymomectomy by video-assisted thoracic surgery. Tumors <5 cm without major invasion on preoperative computed tomography were selected. There were 13 invasive thymomas (Masaoka stage III and IV). A modified dissection technique was employed to prevent breaching the tumor capsule and risking tumor seedling. Limited resection of the phrenic nerve, pericardium, perithymic fat, and a wedge of lung was performed en bloc with the tumor. The mean duration of surgery was 138 min. Hospital stay was 3.6 days. Eleven patients had associated myasthenia gravis. There was 1 case of wound infection and no operative mortality. The mean size of the thymomas was 34 mm (range, 23-55 mm). All patients had adjuvant radiotherapy. During follow-up of 4.9 years (range, 1-10 years), there was one local recurrence. With the modified video-assisted thoracic surgery technique, selected invasive thymomas detected during surgery can be removed safely without resorting to sternotomy.

Technique of the transcervical-subxiphoid-videothoracoscopic maximal thymectomy

Background:

The aim of this study is to present the new technique of transcervical-subxiphoid-videothoracoscopic “maximal”thymectomy introduced by the authors of this study for myasthenia gravis.

Materials and Methods:

Two hundred and sixteen patients with Osserman scores ranging from I–III were operated on from 1/9/2000 to 31/12/2006 for this study. The operation was performed through four incisions: a transverse 5–8 cm incision in the neck, a 4–6 cm subxiphoid incision and two 1 cm incisions for videothoracoscopic (VTS) ports. The cervical part of the procedure was performed with an open technique while the intrathoracic part was performed using a video assisted thoracoscopic surgical (VATS) technique. The whole thymus with the surrounding fatty tissue containing possible ectopic foci of the thymic tissue was removed. Such an operation can be performed by one surgical team (the one team approach) or by two teams working simultaneously (two team approach). The early and late results as well as the incidence and localization of ectopic thymic foci have been presented in this report.

Results:

There were 216 patients in this study of which 178 were women and 38 were men. The ages of the patients ranged from 11 to 69 years (mean 29.7 years). The duration of myasthenia was 2–180 months (mean 28.3 months). Osserman scores were in the range of I–III. Almost 27% of the patients were taking steroids or immunosuppressive drugs preoperatively. The mean operative time was 201.5 min (120–330 min) for a one-team approach and it was 146 (95–210 min) for a two-team approach (P < 0.05). While there was no postoperative mortality, the postoperative morbidity was 12%. The incidence of ectopic thymic foci was 68.4%. The rates of complete remission after one, two, three, four and five years of follow-up were 26.3, 36.5, 42.9, 46.8 and 50.2%, respectively.

Conclusion:

Transcervical-subxiphoid-VTS maximal thymectomy is a complete and highly effective treatment modality for myasthenia gravis. The need for sternotomy is avoided while the completeness of the operation is retained.

Transcervical video-assisted thymectomy: preliminary results of a modified surgical approach

PURPOSE

A number of surgical approaches have been reported for thymectomy, including transsternal, transcervical, a combination of complete transsternal and transcervical, and various video-assisted thoracoscopic surgery techniques. A modified video-assisted transcervical approach to thymectomy is here described.

METHODS

A video-assisted total thymectomy was performed through a 30-mm cervical incision. No hyperextension of the patient's neck or sternal retractor was used. The surgical instruments utilized for the resection were the ones created for the minimally invasive video-assisted thyroidectomy.

RESULTS

Five patients have been operated on so far. The encapsulated gland was removed without any difficulties. No complications occurred. No pain relief was administered after the first 24 h. The patients were discharged within the first two postoperative days. An improvement in clinical symptoms was registered in all patients.

CONCLUSIONS

An advantage of this minimally invasive video-assisted transcervical approach to thymectomy is that the entire operation can be performed without neck hyperextension or permanent sternum elevation. Moreover, the surgical instruments created for minimally invasive video-assisted thyroidectomy enabled us to be very precise and to complete the resection without any postoperative morbidity.

Novel use of the internal thoracic artery retractor in transcervical thymectomy

Transcervical thymectomy is a standard approach to the thymus and anterior mediastinum, but it is limited by poor exposure of the lower recesses of the anterior mediastinum. A novel technique using the widely available internal thoracic artery sternal retractor and a 30°-video camera allows enhanced exposure of the anterior mediastinum.

Visual and systemic outcomes in pediatric ocular myasthenia gravis

PURPOSE

To evaluate visual and systemic outcomes in pediatric patients with purely ocular myasthenia gravis (OMG) treated at the Children's Hospital of Philadelphia.

DESIGN

Retrospective chart review.

METHODS

Pediatric patients with OMG seen at a single institution over a 16-year period with a minimum follow-up of 1 year were reviewed. Associations of demographic and clinical characteristics with disease resolution, amblyopia, and development of generalized symptoms of myasthenia gravis were analyzed.

RESULTS

Thirty-nine patients were identified, with a mean age of 5.4 ± 4.8 years and mean follow-up of 4.8 ± 4.3 years. Fifteen patients were treated with pyridostigmine only, 19 (49%) also received steroids, and 15 (38%) underwent thymectomy. Four patients (10%) received steroid-sparing immunosuppressive therapy. Resolution occurred in 10 patients, and generalized symptoms eventually occurred in 9 patients. Although 10 patients were treated for amblyopia, only 1 had amblyopia at the final visit. There was no correlation between sex or age with amblyopia or development of generalized symptoms. Thymectomy, when performed before the onset of generalized symptoms, showed a trend toward protection from the development of generalized symptoms (P = .07).

CONCLUSIONS

In our series, 24% of patients had disease resolution and 23% had generalized symptoms. Our larger cohort confirms previous findings that treated and untreated pediatric patients with OMG have a relatively low risk of developing generalized symptoms and that related amblyopia is readily reversible. Although our treatments were more aggressive than those previously reported, our rates of amblyopia and development of generalized symptoms are comparable.

Clinical outcome of video-assisted thymectomy for myasthenia gravis and thymoma

We reviewed our experience of video-assisted thoracoscopic thymectomy for myasthenia gravis and thymomas in 119 patients, aged 12-83 years, who were treated between 1998 and 2007. Disease severity was graded using the Osserman classification. To prevent rupture of the tumor capsule and tumor seeding, thymomas were resected using a modified no-touch technique. Thymoma diameters were 10-90 mm (mean, 50 mm). There were no operative deaths, 12 (10%) patients had complications, and 87 (73.1%) improved by 1 or more Osserman grades postoperatively. After follow-up of 1.9-10 years (mean, 4.9 years), 74 (62%) patients remained asymptomatic, with 21% in complete stable remission. Using multivariate regression analysis, there were no statistical differences in median pre- and postoperative Osserman grades with regards to age, sex, duration of symptoms, and presence of thymoma. Video-assisted thoracoscopic thymectomy for myasthenia gravis and selected thymomas can achieve long-term clinical outcomes comparable to those of standard approaches.

Extended transcervical thymectomy: the ultimate minimally invasive approach

The ideal operative technique for thymectomy in myasthenia gravis remains controversial. Most surgeons perform thymectomy through median sternotomy; more recently, thoracoscopic and robotic approaches have been described. "Extended transcervical thymectomy" is an out-patient procedure that appears less morbid and costly than other approaches. It allows a complete extracapsular thymic resection. Kaplan-Meier complete stable remission rates after transcervical thymectomy are 33% and 35% at 3 and 6 years (higher including patients remaining on single-drug immunosuppression). The major surgical complication rate is 0.7%. We believe that this less morbid and less costly operation is a very reasonable choice in the surgical treatment of myasthenia gravis.

Video-assisted thoracic surgery thymectomy: the better approach

Minimally invasive video-assisted thoracic surgery (VATS) thymectomy has evolved significantly over the last decade. The most common indication for VATS thymectomy is the treatment of myasthenia gravis (MG). Video-assisted thoracic surgery thymectomy results in less postoperative pain, better preserved pulmonary function, and improved cosmesis, which can be particularly important to many young female MG patients. Results of VATS thymectomy, in terms of complete stable remission from MG and symptomatic improvement, as well as safety, are comparable with conventional surgical techniques. This more patient-friendly approach would lead to wider acceptance by MG patients and their neurologists for earlier thymectomies and improved outcomes.

Juvenile myasthenia gravis: three case reports and a literature review

Juvenile myasthenia gravis is a rare disorder acquired in childhood, representing 10% to 15% of all cases of myasthenia gravis. Like the adult form, it is generally characterized by an autoimmune attack on acetylcholine receptors at the neuromuscular junction. Most patients present with ptosis, diplopia, and fatigability. More advanced cases may also have bulbar problems and limb weakness. Left untreated, the disease may progress to paralysis of the respiratory muscles. Early recognition of this disease helps avoid unnecessary testing, prevent undue parental anxiety, and stop the progression of symptoms. Here, we relate the clinical course and current status of 3 patients with juvenile myasthenia gravis, discuss the disease in general, and review current treatment modalities.

Thymectomy is more effective than conservative treatment for myasthenia gravis regarding outcome and clinical improvement

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease with a tremendous impact on the quality of life. Controversies over which patients should be operated on because they may benefit most from thymectomy are still ongoing. The aim of this study was to report our long-term results of patients with MG with comparison of thymectomy and conservative treatment.

METHODS

We report a series of 252 patients with MG. Survival data were generated. Patients were seen in the outpatient clinic, where a modified Osserman score and quality of life score were evaluated at the end of the follow-up period for all surviving patients.

RESULTS

A total of 172 patients with MG were followed after thymectomy or with conservative treatment for a median time of 9.8 years. Patients who underwent thymectomy had significantly greater rates of remission and improvement compared with conservative treatment. Furthermore, they had a significantly greater survival.

CONCLUSION

Currently, different effective modalities of treatment are available in patients with MG. In our long-term follow-up, thymectomy was superior to conservative treatment regarding overall survival, clinical improvement, and remission rate. Therefore, thymectomy should be considered strongly for all patients with generalized MG.