Cellular immunity following video-assisted thoracoscopic and open resection for non-thymomatous myasthenia gravis

Myasthenia gravis (MG) is a common chronic disorder of neuromuscular transmission, frequently treated surgically. Little is known about perioperative cellular immune responses following video-assisted thoracoscopic surgery (VATS) when compared with open resection.

Between January and December 2009, 127 patients with non-thymomatous MG underwent surgery, with 54 undergoing VATS and 73 undergoing conventional trans-sternal extended thymectomy (TS). Operative details, ectopic thymic tissue findings, postoperative concentrations of serum immunoglobulin and complement components as well as T-cell immunity were compared in the VATS and TS groups.

There were no between-group differences in patients' age, gender, preoperative duration of MG and operation time. Patients who underwent VATS had a lower rate of postoperative stay in the intensive care unit (P = 0.02), less blood loss (P = 0.01) and a lower probability of ectopic thymic tissue. Prominent cellular immunity difference occurred in serum IgG and C3 concentrations and CD4(+) and CD8(+) T-cell counts between the VATS and TS groups. In VATS patients, serum IgG concentration increased slightly on postoperative days 1 and 3. C3 concentration increased gradually in both groups after surgery, but decreased by postoperative day 7. CD4(+) and CD8(+) T-cell counts were relatively stable postoperatively in the VATS group, but were markedly increased in the TS group on postoperative days 1 and 3, with CD4(+), but not CD8(+), T-cells declining on postoperative day 7.

VATS for non-thymomatous MG has short-term advantages, with less effect on cellular immune responses than open resection.