Mechanical Thrombectomy for Pediatric Stroke

I am doing a meta analysis for a medical school research publication. I have 8 studies and have captured the available medians, IQR, total range for each variable of interest. I do not know how to pool these data together and to assess them collectively. I would like to be able to run some sort of chi-square or something to show variance between one study and the next. Unfortunately, I do not know how to do this. Please see the attached excel file for a rundown of the variables I want to assess. Look at tab 1 of the excel sheet. As one example, in each of these studies, a proportion of the subjects are reported as male. Is there a way I can statistically assess the proportion variance from one study to the next (like a chi-square)? My primary outcome will be the reduction in pre NIHSS and 24-hour post NIHSS. These are stroke scores which will demonstrate the effectiveness of our surgical treatment.