Study limitations
Firstly, although the relatively small number of subjects might underpower the statistical analysis, in this per-segments analysis, 768 regions were considered, which in turn could improve statistical confidence. Secondly, Imp-min and late recurrence had an associative tendency, although not significant in the segments other than SAE, which might be derived from a small number of subjects for statistics. Thirdly, acute PVRs were distributed heterogeneously; therefore, it was preferable to assess each segment to clarify the regional difference in the characteristics of acute PVRs, which requires more number of subjects for evaluation. Lastly, if the impedance-guided HPSD procedure is warranted for clinical practice, its safety aspects, especially regarding esophageal injury, should be assessed as they have not been sufficiently evaluated to date.