Subcostal thoracoscopic extended thymectomy for patients with myasthenia gravis

Background

Extended thymectomy is indicated for patients with myasthenia gravis (MG) when drug-resistance or dependence is seen. We have employed a technique for subcostal thoracoscopic extended thymectomy (STET) on patients with MG.

Methods

Clinical data of 15 eligible patients who underwent STET in our department from February 2015 to November 2015 by the same surgical team were retrospectively analyzed. The operation time, blood loss, duration of postoperative hospital stay, thoracic drainage periods were concerned.

Results

All the surgeries were finished successfully without conversion to sternotomy. Mean operation time was 157.53±40.31 min (range, 73–275 min). Mean blood loss was 56.33±7.07 mL (range, 10–200 mL). Mean pleural drainage volume in the first 24 hours was 72.67±17.68 mL (range, 0–250 mL). Mean postoperative thoracic drainage periods were 1.20±0.71 days (range, 0–3 days). Mean duration of postoperative hospital stay was 6.13±0.71 days (range, 3–22 days).

Conclusions

This procedure showed satisfactory results for patients with MG. Moreover, the STET approach is more easily for surgeons to fully reveal the bilateral phrenic nerve and the upper thymic poles. We believe that STET is a satisfactory procedure for performing extended thymectomy in well selected patients.     

Video-assisted thoracoscopic thymectomy for myasthenia gravis

Background: Thymectomy is an effective, but radical therapy for myasthenia. Video‐assisted thoracic surgery (VATS) may allow a minimally invasive altern­ative to the standard sternotomy approach. Aims: To audit prospectively the outcome of VATS thymectomy for myasthenia gravis in a unit specializing in advanced VATS techniques. Methods: Twenty‐six patients underwent VATS thymectomy between 1997 and 2001. Most underwent preoperative plasma exchange therapy. Seventeen women and nine men with a median age of 36 years (range 17?71 years) had a right‐sided VATS approach to remove all anterior mediastinal fat and thymic tissue. Results: There was no perioperative mortality and all procedures were concluded successfully, with one patient requiring sternotomy. Twenty‐five patients were extubated in theatre and one patient required 17 h of assisted ventilation . The other significant complication was a diathermy injury to the phrenic nerve, which recovered. Median postoperative stay was 4 days (range 2?6 days), with median postoper­ative chest drainage for 2 days (range 1?3 days). Three patients had progression of disease postoperatively. The remainder were asymptomatic (7), improved (14) or stable (2). Conclusion: In a dedicated unit with neurological and intensive care support, VATS thymectomy is a safe, effective method of obtaining remission or improvement in myasthenia gravis (MG). While achieving the same surgical goal, this approach offers advantages of improved cosmesis, shorter recovery time and minimal chest wall disruption over the gold standard of sternotomy. Better patient acceptance of this minimally invasive technique may result in wider application of the benefits of thymectomy in MG. (Intern Med J 2002; 32: 367?371)     

Sevoflurane for trans-sternal thymectomy in myasthenia gravis

Myasthenic gravis (MG) is an autoimmune disease associated with acetylcholine receptor deficiency. Patients with MG exhibit increased sensitivity to non-depolarising muscle relaxants. In an attempt to avoid neuromuscular blockers, we used sevoflurane in two myasthenic patients undergoing trans-sternal thymectomy. Inhalation of 8% sevoflurane in oxygen using vital capacity technique produced rapid, pleasant and smooth induction and provided good tracheal intubating conditions. In both patients anaesthesia was maintained with 1.5-2% end-tidal concentration of sevoflurane and nitrous oxide in oxygen without adjunctive neuromuscular blocking agents. There were minimal changes in cardiovascular variables and recovery was faster. It is suggested that sevoflurane may be the main anaesthetic for both induction and maintenance in myasthenic patients undergoing trans-sternal thymectomy.     

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.     

Video-assisted thoracic surgery thymectomy for nonthymomatous myasthenia gravis

STUDY OBJECTIVES: Minimal-access thymectomy has become increasingly popular as surgical treatment for patients with nonthymomatous myasthenia gravis (NTMG) because of its comparable efficacy, safety, and lesser degree of tissue trauma compared with conventional open surgery. We reviewed and analyzed our data on video-assisted thoracic surgery (VATS) thymectomy and present the clinical outcomes according to the Myasthenia Gravis Foundation of America classification. DESIGN: A retrospective review of VATS thymectomy for NTMG in a university hospital over a 12-year period. Data were collected from the medical records and supplemented with telephone surveys. The impact of surgery and other variables potentially affecting complete stable remission (CSR) were calculated using Kaplan-Meier survival curves; comparisons between survival curves was performed using the log-rank test. RESULTS: A total of 38 consecutive patients underwent VATS thymectomy for NTMG. Median postoperative stay was 3 days. Pathologic examination revealed thymic hyperplasia in 61.1% of cases, normal thymus in 22.2%, and thymic atrophy in 16.6%. There was no perioperative mortality; complications occurred in four patients. After a median follow-up of 69 months, 91.6% of patients experienced improvement, with crude CSR achieved in 22.2%. Kaplan-Meier survival curve demonstrated a 75% CSR rate at 10-year follow-up. On univariate analysis, only disease duration < or = 12 months (p = 0.03) was associated with a statistically significant improvement in CSR. CONCLUSIONS: VATS thymectomy for NTMG results in symptomatic improvement in the vast majority of patients, with a high rate of CSR. The procedure is associated with low morbidity and no perioperative mortality. Future studies on thymectomy for myasthenia gravis should be reported in a standardized manner to allow accurate comparisons between results in the absence of randomized prospective trials.     

Robotic thymectomy for myasthenia gravis surgical techniques and outcomes

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

Discordant thymectomy in identical twins concordant for myasthenia gravis

BACKGROUND: Thymectomy is standard therapy fornonthymomatousmyasthenia gravis despite the absence of randomized clinical trials (1). Myasthenia gravis is uncommonly reported in monozygous twins; disease concordance occurs in approximately one third of such identical twin pairs; and treatment for myasthenia gravis, when described,is usually concordant in identical twin pairs (2).OBJECTIVE: To report an 11-year clinical course of a pair of identical twins concordant for generalized acetylcholine receptor antibody–positive nonthymomatous myasthenia gravis in whom only 1 was treated with extended transsternal thymectomy. CASE REPORT: Twin A was a 19-year-old white woman who presented with an 8-week history of intermittent leg weakness, causing her to fall during activities, such as climbing stairs. On examination,she had moderately severe fatigable proximal muscle weakness and ptosis. Her weakness improved with intravenous edrophonium administration.Initial binding acetylcholine receptor antibody titer was 1.22 nmol/L (normal value, 0.03 nmol/L). Repetitive 2-Hz nerve(median, ulnar, and facial) stimulation studies demonstrated up to a 16% decremental response. Chest computed tomography showed residual thymic tissue without thymoma. An extended transsternal thymectomy was performed 11 weeks after the onset of symptoms.     

Complications and efficacy of transsternal thymectomy in myasthenia gravis

Between January 1977 and September 1985, 75 patients in our department underwent elective surgery for myasthenia gravis through a median sternotomy. The main prerequisite was optimal stabilization by medical treatment with the best possible vital capacity. The Osseman types were as follows: type I (22), type IIa (19), type IIb (26), type III (7), and type IV (1). All patients, except for 3 who were mechanically ventilated for a few hours after surgery, were immediately extubated at the end of the operation. The most frequent histologic finding was thymic hyperplasia (36%); 21.3% of the patients had thymomas. No surgery-related deaths occurred. Wound healing was impaired in 6.7% of the patients, including one patient with complete sternal instability, while 5.3% developed pneumonia. The most serious complications were myasthenic (9.3%) and cholinergic (2.7%) crises. Paresis of the phrenic (2.7%) and recurrent laryngeal (1.3%) nerves occurred only in the thymoma patients, who also had a higher frequency of all other complications. The effect on the myasthenic symptoms 3 months after surgery was as follows: 7.5% of the patients were in complete remission, 61.2% had improved, 9% had deteriorated. In a logistic regression model, the parameters age, sex, duration of disease, Osserman type, histology, pre-operative antibody titer to acetylcholine receptors, and post-operative change in titer were examined with respect to their influence on the effect of surgery. Only thymic histology had an appreciable influence (p = 0.057). The effect of these parameters on the success of surgery as well as the type and frequency of complications in relation to perioperative procedure are discussed in detail.     

Crohn's disease and myasthenia gravis: a possible role for thymectomy.

A female patient with a three year history of Crohn's disease of the colon developed myasthenia gravis. Despite diversion of the faecal stream by an ileostomy, and total colectomy, the patient had continuing problems with perineal and perianal abscesses and fistulas. Her myasthenia gravis became unresponsive to anti-cholinergics so a thymectomy was performed. The perineal and perianal disease improved subsequently. This case supports the theory that functional disturbances of the thymus may have a role in the pathogenesis of inflammatory bowel disease.     

Factors influencing improvement and remission rates after thymectomy for myasthenia gravis.

BACKGROUND: Thymectomy has become an accepted option in the treatment of myasthenia gravis (MG). However, the optimal selection of patients for surgery remains controversial. OBJECTIVE: The objective of the study is to define factors influencing improvement and remission rates after thymectomy for MG. METHODS: We retrospectively reviewed our experience in the surgical management of patients with MG over the last 20 years, and analyzed if patient's age, sex, preoperative Osserman Stage, thymic histology, duration of symptoms, or radiological findings influenced outcome. RESULTS: There were 25 women and 10 men. Most of them presented with Osserman stage IIA (n = 12) and stage IIB (n = 17). Hyperplasia of the thymus was observed in 15 patients (43%), thymoma in 12 (34%), and atrophic or normal thymus in 8 (23%). Computed tomography (CT) had a positive predictive value of 91% in detecting thymoma and of 80% in detecting thymic hyperplasia. Over a mean follow-up of 96 months, MG improved markedly in 26 patients. Postoperative improvement was significantly greater in patients with advanced MG (stage IIB, III and IV), whereas a higher rate of remission occurred in patients with mild MG (stage I and IIA), and in those with thymic hyperplasia. No relation was observed between outcome and age, sex, duration of symptoms and abnormal CT findings. CONCLUSIONS: The beneficial effects of thymectomy are characterized by postoperative clinical improvement in most patients with moderate to severe preoperative myasthenic involvement and by a higher remission rate in patients with thymic hyperplasia and/or mild myasthenic symptoms.     

Recurrence of thymic hyperplasia after trans-sternal thymectomy in myasthenia gravis

A 23-year-old woman with myasthenia gravis underwent thymectomy in September, 1975 by a trans-sternal approach for the removal of an hyperplastic gland. Surgical intervention was followed by marked improvement of her symptoms. Five years later, symptoms recurred. In March, 1982 diagnostic pneumomediastinum disclosed an anterosuperior mediastinal mass which, on excision, proved to be an hyperplastic thymus. This report confirms previous findings of thymus regrowth after surgery. It also demonstrates that surgical techniques using the trans-sternal approach do not guarantee complete removal of the thymus.