Robotic thymectomy safe, effective for treating MG: Study
Long-term improvements seen for most patients
Robotic thymectomy is a safe and effective treatment for people with myasthenia gravis (MG), including patient groups that have historically showed poorer outcomes, a study found.
Five years after undergoing robotic thymectomy, a minimally invasive surgery to remove the thymus gland, 84% of patients saw their MG symptoms ease, and 18% were in complete remission. Based on the relative rarity of complications seen during and after surgery, the researchers said, “robotic thymectomy in patients with MG is a safe surgical procedure.”
The study, “Robotic Thymectomy for Myasthenia Gravis: Analysis of the Surgical and Neurological Outcomes After a 20 Years’ Experience,” was published in the European Journal of Neurology.
The thymus gland is an immune organ located in the upper chest that researchers think may contribute to the production of the self-reactive antibodies that drive MG. These antibodies target proteins involved in nerve-muscle communication, disrupting the process, and leading to muscle weakness and other MG symptoms.
In a thymectomy, surgeons remove the thymus gland, which is abnormal in many MG patients. The procedure is also used to remove tumors, or thymomas, which are seen in 10%-15% of people with MG. A randomized clinical trial demonstrated that when used in combination with medication, thymectomy is superior to medical therapy alone at improving the clinical outcomes of MG patients.
More precise, less invasive
In recent decades, robotic systems have been developed to assist during the procedure. Robotic thymectomies can be more precise and less invasive, providing more favorable surgical outcomes.
Yet studies of robotic thymectomies have been small and had limited follow-up time, according to the research team.
“Needing larger and more consistent data, our present study was specifically conducted to evaluate the surgical and long-term outcomes of robotic thymectomy, analyzing our 20 years’ experience,” they wrote.
The study looked at 267 patients who were followed for a median of 83 months (about seven years). Participants underwent robotic thymectomies between 2002 and 2022 at the University Hospital in Padua, Italy. At the time of surgery, they had a median age of 42 and had been exhibiting symptoms for a median of 11 months.
Five years after the operation, 18% of the patients were in complete stable remission, meaning they had been symptom-free for at least a year without receiving any MG treatment. Some 84% of the patients showed improvements on the MG Foundation of America Post-Intervention Status (MGFA-PIS) rating scale, meaning they had attained a status of minimal manifestations (no functional limitations from MG, while having some degree of muscle weakness), pharmacological remission (symptom-free for at least one year while receiving MG treatment), or complete stable remission.
After 10 years, 92% experienced improvements and 36% were in complete stable remission.
A relatively large portion of patients taking two commonly prescribed MG medications, pyridostigmine (sold as Mestinon, also available as generics) and steroids before surgery, managed to reduce the dosage or interrupt treatment altogether over the course of follow-up.
Statistical models showed that people who were younger at the time of the operation and those who were not prescribed pyridostigmine were more likely to reach complete stable remission.
Patients who had surgery later in the time period studied were also more likely to achieve complete stable remission. Because there were no major changes in MG treatments during this time, small improvements in robotic systems, surgeon experience, and neurological care at the hospital could explain this effect, the researchers said.
Unlike the previous clinical trial, this study included people who did not test positive for MG-causing antibodies, as well as those with thymoma. These factors did not have a significant effect on the rate of complete stable remission, supporting the efficacy of robotic thymectomy in these groups of MG patients.
The team also examined the safety of the procedure over the 20-year study period. About 7% of patients experienced postoperative complications, most commonly myasthenic crisis, which happens when respiratory muscles become too weak to support breathing. There were no deaths associated with the surgery.
“This large 20 years’ single-center experience showed that extended robotic thymectomy in patients with MG is a safe surgical procedure,” the researchers wrote. “Long-term neurological follow-up shows high efficacy, with remission or reduction in medication in most patients, also in those subgroups that historically showed worse outcomes, as patients with thymoma, seronegative disease or advanced MGFA class.”
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