Background: Transurethral resection of prostate  is a “gold standard” of bening prostatic hyperplasia surgical treatment. However, up to 30% of patients after transurethral resection of prostate still keep storage symptoms. The persisting of urgency after transurethral resection of prostate mainly explains poor life quality and unsatisfactory results of surgery. Patient Global Impression of Improvement (PGI-C) scale is a convincing tool, allowing to evaluate the patient satisfaction after treatment. In patients majority the urodynamic marker of urgency is detrusor overactivity detected by cystometry.  The type of detrusor overactivity in benign prostatic hyperplasia patients can be an important predictor of transurethral resection of prostate symptomatic outcome.  
Objective: to evaluate Patient Global Impression of Improvement after transurethral resection of prostate in patients with high and low amplitude detrusor overactivitybe detected by cystometry before surgery.

180 benign prostatic hyperplasia patients (mean age 62.5 yrs) hospitalized for transurethral resection of prostate were clinically assessed for study participation eligibility. Inclusion criteria were as follows: the presence of urgency symptoms; involuntary detrusor contractions during the storage phase of urodynamic filling cystometry. Patients with detected detrusor overactivity were divided into two groups according the amplitude of maximal detrusor contraction during filling (Pdetmax). We accepted Pdetmax < 20 cmH2O as low-amplitude detrusor overactivity and  Pdetmax >20 cmH2O as high-amplitude detrusor overactivity. Patient Global Impression of Improvement was used to evaluate the patient's impression of improvement 2 months after transurethral resection of prostate.

Detrusor overactivity was detected in 108 (60%) of 180 patients before surgery.  51 (47.2%) patients demonstrated high-amplitude detrusor overactivity with mean Pdetmax = 29.8 ± 2.3 cmH2O. 57 (52.8%) patients demonstrated detrusor overactivity with mean Pdetmax= 16.8 ± 1.7 cmH2O. After transurethral resection of prostate  Patient Global Impression of Improvement in the first group was estimated as 3.75 ± 0.2 and 2.45 ± 0.5 in the second group (p<0,01).

Patients with pre-operative high-amplitude detrusor overactivity have significantly worse transurethral resection of prostate effect evaluated by Patient Global Impression of Improvement in comparison with pre-operative low-amplitude detrusor overactivity.

High-amplitude detrusor overactivity can be considered as a predictor of unsatisfactory symptomatic transurethral resection of prostate results.