Videothoracoscopic thymectomy for nonthymomatous myasthenia gravis: Results of 90 patients

History of Myasthenia Gravis Revisited

The first description of myasthenia gravis (MG) was given by Thomas Willis in 1672. MG was the focus of attention after mid-nineteenth century and a great amount of information has been accumulated in a span of 150 years. The aim of this review is to convey this information according to a particular systematic and to briefly relate the experience of Istanbul University. MG history was examined in four periods: 1868-1930, 1930-1960, 1960-1990, and 1990-2020. In the first period (1868-1930), all the clinical characteristics of MG were defined. Physiological/pharmacological studies on the transmission at the neuromuscular junction were initiated, and the concept of repetitive nerve stimulation emerged. A toxic agent was believed to be the cause of MG which appeared to resemble curare intoxication. Association of MG with thymus was noticed. No noteworthy progress was made in its treatment. In the second period (1930-1960), acetylcholine was discovered to be the transmitter at the neuromuscular junction. Repetitive nerve stimulation was used as a diagnostic test. The autoimmune nature of MG was suspected and experiments to this end started to give results. The hallmark of this period was the use of anticholinesterases and thymectomy in the treatment of MG. The third period (1960-1990) can probably be considered a revolutionary era for MG. Important immunological mechanisms (acetylcholine receptor isolation, discovery of anti-acetylcholine receptor antibodies) were clarified and the autoimmune nature of MG was demonstrated. Treatment modalities which completely changed the prognosis of MG, including positive pressure mechanic ventilation and corticosteroids as well as plasma exchange/IVIg and azathioprine, were put to use. In the fourth period (1990-2020), more immunological progress, including the discovery of anti-MuSK antibodies, was achieved. Videothoracoscopic thymectomy reduced the morbidity and mortality rate associated with surgery. New drugs emerged and clinical trials were performed. Valuable guidelines were published. In the last part of the review, the experience in MG of Istanbul University, a pioneer in Turkey, is related.

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.

Unilateral extended thoracoscopic thymectomy for nontumoral myasthenia gravis--a new standard

Myasthenia gravis (MG) is a heterogeneous disorder with a fluctuating, clinical, pathologic, and immunobiological picture. Today, it is believed that effective treatment of MG must include both immunosuppression and surgery. Thymectomy is recommended by neurologists for patients with nontumoral MG as an option to increase the probability of remission or improvement. Currently, thoracoscopic thymectomy is considered a good alternative to the standard open approach because of its higher rate of acceptance, low morbidity, and high efficacy, as measured by complete stable remission rates. We present a review of the experience of unilateral extended thoracoscopic thymectomy for nontumoral MG, a technique that could became a new standard in the complex management of MG treatment.

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.

Does a relationship exist between the number of thoracoscopic thymectomies performed and the learning curve for thoracoscopic resection of thymoma in patients with myasthenia gravis?

This study aimed to analyze surgeons' learning curve for thymoma resection with video-assisted thoracoscopic surgery (VATS). Two hundred and eleven myasthenia gravis patients had VATS thymic resections, including 25 patients with a thymoma. Three groups of surgeries, according to the order of operations, were analyzed: Group A comprised the first 70 thymectomies, Group B comprised the second 70 thymectomies, and Group C comprised the final 71 thymectomies. We compared the groups on a set of preoperative (age, gender, body mass index, and Osserman stage), operative (number in each group, size, and Masaoka stage), and postoperative (complications and length of stay) variables. A significant difference was observed in the number of thymoma operations (Group A: four patients, Group B: seven patients, and Group C: 14 patients; P: 0.031) and the duration of operation (Group A: 66 min, Group B: 52 min, and Group C: 48 min; P: 0.024). A strong correlation was found between the duration of operation and order of patients (Pearson r: -0.554, P: 0.000). We recommend the start of a program for the resection of thymoma with VATS after surgical staff have performed 70 VATS thymectomy operations.

Extended videothoracoscopic thymectomy in nonthymomatous myasthenia gravis

Myasthenia gravis (MG) is an uncommon, organ-specific, autoimmune chronic neuromuscular disorder involving the production of autoantibodies directed against the nicotinic acetylcholine receptors (anti-AchRab). It is characterized by weakness and rapid fatigability of voluntary muscles. Thymectomy is performed early in the course of the disease and is indicated for adults less than 70 years old. For many years, the clinical efficacy of thymectomy has been questioned and so far, its benefits in nonthymomatous MG have not been firmly established. Furthermore, the precise mechanisms of action of thymectomy are unknown although possible explanations include removal of the source of continued antigen stimulation and of the AchRab-recruiting B-lymphocytes as well as immunomodulation. However, thymectomy remains indicated in patients with MG and is widely applied to increase the probability of improvement or remission. This article presents the evolution of technical and surgical advances achieved within the authors' program of extended endoscopically assisted thymectomy since 1995. The use of video-assisted thoracic surgery and its variants for performing thymectomy in MG patients is now well established and will continue to evolve for further improvement in the results.

Myasthenic crisis

Myasthenic crisis is a life-threatening medical emergency requiring early diagnosis and respiratory assistance. It can affect between one-fifth and one-third of all patients with generalized autoimmune myasthenia gravis. Myasthenic crisis is to be distinguished from other causes of acute neuromuscular paralysis which in most cases, can be achieved clinically. High dose corticosteroids in combination with plasma exchange or immunoglobulin are the cornerstone of treatment for this fully reversible cause of neuromuscular paralysis.