Impact of the surgical approach to thymectomy upon complete stable remission rates in myasthenia gravis: a meta-analysis

Objectives: To determine whether any of the available operative techniques confer variable chances for complete stable remission (CSR) in myasthenia gravis (MG), we performed a meta-analysis of all comparative studies of surgical approaches.

Methods: Meta-analysis of all studies providing comparative data on thymectomy approaches, with CSR reported and minimum 3 years mean follow-up.

Results: 12 cohort studies and one randomized clinical trial, containing 1598 patients, met entry criteria. At 3 years, CSR from MG was similar following VATS extended vs. both basic (RR 1.00, p=1.00, 95% CI 0.39-2.58) and extended (RR 0.96, p=0.74, CI: 0.72-1.27) transsternal approaches. CSR at 3 years was also similar following extended transsternal vs. combined transcervical-subxiphoid (RR 1.08, p=0.62, CI: 0.8-1.44) approaches. VATS extended approaches remained statistically equivalent to extended transsternal approaches through 9 years of follow-up (RR 1.51, p=0.05, CI: 0.99-2.30).  The only significant difference in CSR rate between a traditionally open and a minimally invasive approach was seen at 10 years when comparing the now-abandoned basic (non-sternum-lifting) transcervical approach and the extended transsternal approach (RR 0.4, p=0.01, CI: 0.2-0.8).

Conclusions: A significant difference in the rate of CSR among various surgical approaches for thymectomy in MG was identified only at long-term follow-up, and only between what might be considered the most aggressive approach (extended transsternal thymectomy) and the least aggressive approach (basic transcervical thymectomy).  Extended minimally invasive approaches appear to have equivalent CSR rates to extended transsternal approaches and are therefore appropriate in the hands of experienced surgeons.