Strengths and limitations
Our meta-analysis possesses several strengths. Our findings were comparable to those presented in the previously published meta-analyses.34–36 Unlike the preceding meta-analytic publications about the same topic, the present study included more randomized controlled trials and other comparative studies which the search had yielded. Aiming at a better assessment of efficacy and safety, we also added more parameters for comparison. As much as we could, we held some variable risk factors constant, such as the source of the graft tissue and the graft placement method, to reduce clinical heterogeneity.
Admittedly, our meta-analysis has a few limitations. There was a noticeable variance in the other risk factors influencing surgical outcomes (e.g. the age of patients, and the size or location of TM perforation). This variance resulted in raising concerns about clinical heterogeneity. Furthermore, publication bias with highly significant heterogeneity could limit the integrity of our analytic results regarding operative time and ABGs improvement. Nevertheless, this study provided results that may be beneficial to decision-making and outcome prediction in patients receiving ET.