On intention-to-treat analysis , both the PKEP and OP groups had equivalent Qmax ( @ ml/s vs @ ml/s , respectively ; p = @ ) , International Prostate Symptom Score ( @ -LSB- @-@ -RSB- vs @ -LSB- @-@ -RSB- , respectively p = @ ) , quality of life ( @ -LSB- @-@ -RSB- vs @ -LSB- @-@ -RSB- , respectively ; p = @ ) , and postvoid residual urine ( @ -LSB- @-@ @ -RSB- vs @ -LSB- @-@ -RSB- ml , respectively ; p = @ ) at @ mo postoperatively .