Hypothesis / aims of study
The Prostatic urethral Lift (PUL) is a minimal invasive endoscopic technique for treatment of LUTS in males with benign prostatic obstruction (BPO). Literature already showed that this technique provides a comparable decrease of LUTS as after TURP, whereas uroflowmetry just shows an improvement in flow comparable to an alfa-blocker.1,2 Therefore we performed this pilot study to assess PUL urodynamically.
Primary objective is to investigate whether PUL results in a negative shift in urodynamic parameters that define bladder outlet obstruction (urethral resistance algorithm [URA], Schäfer grade, PdetQmax, PdetOpen).
Study design, materials and methods
Twenty patients (main inclusion criteria: ≥ 50 years of age, BPO, IPSS ≥ 13, a prostate volume ≤ 60 mL, without a middle prostatic lobe) were enrolled in the study and a PUL (Urolift® System) was performed. Patients underwent urodynamics and filled out the IPSS and ICIQ QoL before and after PUL. A paired T test was used to analyze the results. A p-value ≤ 0.05 was considered significant.
Results
The mean age was 68 years (range 55-79), mean prostate volume (TRUS) was 45 mL (range 20-59) and mean PSA was 2.0 ug/L (0.2-4.4). Of 16 patients urodynamic traces were analyzable pre- and postoperative. IPSS reduced significantly after 3 months. Also the IPSS quality of life improved significantly after surgery. Qmax during pressure flow study improved significantly, whereas there was no significant difference found in Qmax during free flow study. When corrected for volume voided > 150ml (n=6 both pre and post treatment), there was also no significance in free Qmax pre- and post-treatment. There was no significant difference found in post voiding residual volume before and after treatment. Although opening pressure of the bladder decreased after surgery, this difference was not significant. Also closure pressure of the bladder remained unchanged after surgery. URA decreased significantly post treatment. The Schäfer obstruction plot decreased significantly. If we consider a URA of < 29 cmH2O as nonobstructive, 13 patients had an obstructive URA pre-treatment (we observed 3 missing values) and 10 patients still had an obstructive URA post-treatment (1 missing value). When we consider Schafer obstruction plot ≥ III obstructive, 11 patients had obstructive Schafer plots pre-treatment (1 missing value), and 7 patients had obstructive Schafer plots post-treatment (0 missing values). Seven patients were converted to Greenlight Laser Vaporization due to unsatisfactory result after 3 months.
Interpretation of results
PUL decreases LUTS subjectively based on improvement of IPSS including the QoL question, which has been shown previously and was also observed in this study. The mean improvement is from the moderate/severe range (IPSS 22) to the moderate range (IPSS 14). This study furthermore analyzed the urodynamic pressure flow results. When interpreting the obstruction plots URA and the Schäfer classification, the desobstructing effects are modest at best. Analyzing URA, 10/13 (76%) were still obstructed after PUL treatment. With the Schäfer classification 7 out of 11 (64%) still were obstructed.