Relative locations of ECs and isolation lines and their association with first-pass isolation success rate
The success rate of first-pass isolation was similar between the EC-negative and EC-positive groups (36/51, 70.6% vs. 14/23, 60.9%; ns) (Table 2).
In the EC-positive group, patients were also divided into three groups according to the relative location of the EC site and the originally designed isolation line (on-the-line group, 11 patients; inside-line group, 10 patients; outside-line group, 2 patients). The ECs were located on the anterior to the carina segment of the right-sided PV (10 patients in the on-the-line group and 9 patients in the inside-line group) and anterior segment of the right inferior PV (1 patient in the on-the-line group, 1 patient in the inside-line group, and 2 patients in the outside-line group). The distance from the EC site to the center of the carina segment was not significantly different among the three groups (Table 3). The success rate of first-pass isolation in the on-the-line group was significantly higher than that in the inside-line group (10/11, 91% vs. 2/10, 20%; p=0.0019) (Figure3).