Fig. 6
![Fig. 6](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12894-017-0239-x/MediaObjects/12894_2017_239_Fig6_HTML.gif)
Forest plots for operation time using pairwise meta-analysis. a Standard versus total tubeless PCNLs, b standard versus tubeless PCNLs, and c tubeless versus small-bore PCNLs. SD, standard deviation; MD, Mean difference; CI, confidence interval; W, Weight