Fig. 4
EFS-induced contractions in laser-enucleated tissues, grouped for preoperative catheterization and preoperative treatment with α1-blockers. Data from EFS-induced contractions were grouped as indicated, for preoperative catheterization of patients due to urinary retention (a), for preoperative treatment with α1-blockers (b), or both (c-f). Patients’ data regarding catheterization and medical treatment were available from 47 of a total of 51 patients participating in this series (25 without, 22 with catheter; 26 treated, 21 not treated with α1-blocker). Shown are means ± standard deviation (SD) in frequency response curves, and all single values for Emax and EF50 calculated by curve fitting (each value representing one prostate tissue, examined by single or multiple determinations) together with means (bars). Frequency response curves were compared by two-way ANOVA. Emax and EF50 values were compared by unpaired, two-tailed t test if data were normally distributed in both groups (i. e., EF50 values in (b) and (f)), and by unpaired, two-tailed Mann Whitney test if data were not normally distributed in at least one of both groups (all others). P values ≥ 0.05 are not shown. One EF50 value (labelled by grey color) could not be calculated by curve fitting, as the sample showed no contraction (corresponding to an Emax of 0% of KCl), but was set to the highest applied frequency, i.e. 32 Hz for illustration.
