Dear Editor-in-Chief,

We read the paper by Taterra et al. [1] with interest. The authors performed a meta-analysis with 60 studies met the inclusion criteria, providing data for 5437 patients to provide comprehensive data on the prevalence and anatomical characteristics of the AKA. They concluded that as an AKA is present in the majority of the population, caution should be taken during vascular and endovascular surgical procedures to avoid injury or ensure proper reconstruction. All surgeons operating in the thoracolumbar spinal cord should have a thorough understanding of the anatomical characteristics and surgical implications of an AKA. After carefully reading, we wish to put forth the following suggestion.

Repeatedly including the same study population will affect the total sample size and the number of participants in each group; thus, duplicated studies using the same study population should not be included in a meta-analysis. However, we found that data from several studies may have by error been included twice due to reporting of different aspects of the study in separate publications, which significantly affect the reliability of the results. For instance, the studies in the references 27 [2], 28 [3], and 29 [4], included for the characteristics of included trial comparisons, were conducted by the same group of authors, the participants are from the same country, and have the same number of participants. Hence, we suspect that these are two duplicate studies. Similarly, the references 31 and 33; 34 and 35; 39 and 40; 10, 46 and 47; and 55 and 56 are duplicates, too. Therefore, we suspected that this article might include more of the same studies and the same patients. The authors should formulate strict inclusion and exclusion criteria, eliminate duplicate documents that employ the same study population, and select the ones with the best quality or the largest sample size for analysis.