Minimally invasive lumpectomy has become pivotal in surgery, whether in general surgery, urology, orthopedics or thoracic surgery, the application of lumpectomy has broken through one forbidden area after another. While surgical techniques are constantly developing breakthroughs, the majority of patients are also benefiting from them. Myasthenia gravis (MG) is a neuromuscular disease characterized by neuromuscular conduction disorders of the transverse muscles. The typical manifestation of MG is: “The transverse muscles are easily fatigued and weak after activity, among which the eye muscles are most easily involved, manifesting as eyelid drooping, with symptoms usually light in the morning and heavy in the evening, and corresponding dysphagia and dyspnea when the pharyngeal muscles and diaphragm are affected”. More than 80% of myasthenia gravis patients have thymic hyperplasia or thymoma, of which 15-30% are thymoma. “Thymectomy has been recognized as an effective treatment for myasthenia gravis. According to the literature, 80-90% of patients have varying degrees of remission after thymectomy, and 25-50% of these patients can completely stop taking anticholinesterase drugs. Conventional thymectomy is usually a median splitting of the sternum and removal of the thymus as well as all the fat in the mediastinum. So what is the key to this procedure? Director Gu Lijia said, “In fact, traditional thymectomy is not difficult, but often many patients have poor post-operative results because the ‘ectopic thymus’ in the mediastinal fat is not completely removed. Thorough removal of the ectopic thymus is the key to successful surgery. Traditional surgery for myasthenia gravis is effective, but it has many shortcomings. Firstly, the sternum needs to be split and propped open during surgery, and then fixed with wire sutures, which often affects patients’ coughing and breathing due to pain. especially those taking hormones at the same time, sternal non-healing and infection are one of the main postoperative complications.” Thoracoscopic techniques have been performed in our cardiothoracic surgery department for more than 10 years, and have been widely used in pneumothorax, pulmonary esophageal tumors, mediastinal tumors, and hyperhidrosis. So, can thoracoscopic technology play an advantage in the treatment of myasthenia gravis? Director Gu Lijia said, “The key to surgical treatment of myasthenia gravis is to completely remove the ‘ectopic thymus’ in the mediastinum, and whether thoracoscopy can completely remove the mediastinal fat becomes the key to surgery”. Through the collection and study of foreign related literature, combined with the application of anatomical study of mediastinal surgery under lumpectomy, our department gradually carried out expanded thoracoscopic thymectomy. The key to the operation is “to take advantage of the minimally invasive thoracoscope and at the same time to ensure complete removal of the thymic tissue in the mediastinum”. The difficult part of the lumpectomy was to remove the fatty tissue from the contralateral diaphragm. In high-definition lumpectomy, the microscopic magnification of the camera system allows for clearer separation of fat and blood vessels than in direct vision surgery, and there is no “unreachable” dead zone in lumpectomy. At present, “total thoracoscopic enlarged thymectomy” is a routine operation in our cardiothoracic surgery department. Compared with the traditional surgery, the operation time is shorter, the trauma is significantly reduced, the patient recovers faster after the operation, there is no damage to the bony thorax and respiratory muscles, the postoperative pain is significantly reduced, the incidence of lung infection and respiratory failure is significantly reduced, and there are only three scars about 1-2 cm long in the inconspicuous area of the armpit. The reduced aesthetic impact makes it easier for more young female patients to undergo the surgery. According to our department, the total cost of hospitalization is lower than that of traditional surgery due to shorter hospital stays and fewer postoperative complications.