Advanced minimally invasive approaches to thymectomy are associated with complete stable remission (CSR) rates similar to those achieved with advanced transsternal approaches and may be preferable in patients with myasthenia gravis (MG) according to a meta-analysis published in Neurology .
While several case series have demonstrated the benefits of a thymectomy in patients with MG, there is only one prospective randomized study on the subject. The thymectomy study in patients with non-thymomatous myasthenia gravis who received prednisone (MGTX) showed that thymectomy with prednisone was superior to treatment with prednisone alone. However, the optimal surgical technique was not clear.
The current meta-analysis of studies comparing 2 or more surgical approaches to thymectomy aimed to determine which type of surgery is best for patients with MG. The international team of study authors emphasized that the best surgical approach is the one that is least invasive, but achieves the same CSR rates as more morbid approaches.
This systematic review comprised 13 comparative studies, including 12 cohort studies and a single randomized clinical study with a total of 1,598 patients with MG (mean age 20.50-43.96 years; 65% female).
The combined transcervical / subxiphoid approach was the technique with the longest average total operating time (181.31 minutes), while the transsternal base technique had the shortest average operating time (86.83 minutes).
Two studies compared different degrees of thymus resection using a median sternotomy. After 3 years, the risk of achieving CSR was similar in patients who underwent extended transsternal versus simple transsternal thymectomy (P = 0.58). The same was true for 5 years of follow-up.
The comparison of different dimensions of transsternal thymectomy with different minimally invasive approaches was carried out in 9 studies. After 3 years, the risk of achieving CSR from MG was similar after video-assisted thoracoscopic extended and basic transsternal approaches (P = 1.00). This estimate remained unchanged up to a follow-up period of 5 years. There was no difference in the CSR rates achieved by the extended video-assisted thoracoscopic thymectomy compared to the extended transsternal thymectomy at any time point up to 9 years of follow-up (relative risk [RR], 1.51; 95% CI 0.99-2.30; P = 0.05).
While there was no difference in CSR after 3 years in patients with a combined transcervical / subxiphoid vs. extended transsternal approach (P = .62), the combined approach was superior to the basic transsternal approach (RR 3.06; 95% CI, 1, 65-5.66; P <0.001).
The only significant difference in the CSR rate between a traditional open and a minimally invasive approach was found after 10 years when the now-abandoned basic transcervical approach (without sternum lifting) was compared to the extended transsternal approach (RR 0.40 ; 95.). % CI, 0.20-0.80; P = 0.01).
The study had several limitations; These included the inclusion of only a single randomized controlled trial, small cohort sizes, significant publication bias, and the fact that all studies were conducted outside of North America.
“This meta-analysis suggests that, despite the fact that the MGTX study envisioned an advanced transsternal technique, neurologists should feel comfortable referring their MG patients to experienced thymic surgeons who prefer advanced minimally invasive thymectomy approaches (e.g. [video-assisted thoracoscopic surgery] or robotic, enlarged transcervical, combined transcervical subxiphoid), ”the researchers concluded.
Solis-Pazmino P, Baiu I, Lincango-Naranjo E, et al. Influence of the surgical approach to thymectomy on completely stable remission rates in myasthenia gravis: a meta-analysis. Neurology. 2021; 97 (4): e357-e368. doi: 10.1212 / WNL.0000000000012153