Urodynamics and laser prostatectomy

[S2e guideline of the German urologists: Instrumental treatment of benign prostatic hyperplasia]

This report summarizes the relevant aspects of the S2e guideline of the German Urologists for the instrumental treatment of the lower urinary tract symptoms due to benign prostatic hyperplasia. Recommendations are given regarding open and transurethral procedures (TUR-P, bipolar TUR-P, TUI-P, HE-TUMT, TUNA, and the different Laser techniques). Recommendations are also given concerning intraprostatic stents and injection therapies. The influence of the different therapeutic options on bladder outlet obstruction (BOO) is described in detail.

Comparative study of pressure-flow parameters

Methods for quantification of bladder outlet obstruction (BOO) are still controversial. Parameters such as detrusor opening pressure (p(det.open)), maximum detrusor pressure (p(det.max)), minimum voiding pressure (p(det.min.void)), and detrusor pressure at maximum flow rate (P(det.Qmax)) separate obstructed from nonobstructed patients to some extent, but two nomograms, the Abrams-Griffiths nomogram and the linearized passive urethral resistance relation (LinPURR), are more accepted for this purpose, along with the urethral resistance algorithm. In this retrospective, methodologic study, we evaluated the properties of these parameters with regard to test-retest reproducibility and ability to detect a moderate (pharmacologic) and a pronounced (surgical) relief of bladder outlet obstruction. We studied the pressure-flow charts of 42 patients who underwent 24 weeks of androgen suppressive therapy, 42 corresponding patients who received placebo, and 30 patients who had prostate surgery. The patients performed repeat void pressure-flow examinations before and after treatment or placebo. The various parameters were compared. Among the bladder pressure parameters, P(det.Qmax) seemed to have some advantages, supporting the belief that it is the most relevant detrusor pressure parameter to include in nomograms to quantify BOO. In assessment of a large decrease in urethral resistance, such as after TURp, resistance parameters that are based on maximum flow rate as well as detrusor pressure are preferable.

Urodynamic effects of various treatment modalities for benign prostatic hyperplasia

PURPOSE

I studied the effects of various treatments for benign prostatic hyperplasia on urethral resistance.

MATERIALS AND METHODS

I reviewed the literature on urodynamic effects of treatments for benign prostatic hyperplasia. Articles that reported pretreatment and posttreatment values of relevant urodynamic parameters were analyzed. Average before and after treatment values of maximum flow rate and detrusor pressure at maximal flow rate for every study were plotted on an Abrams-Griffiths nomogram and classified as obstructed, equivocal or nonobstructed. Average values of maximum flow rate and detrusor pressure at maximal flow rate were calculated for the total number of patients treated by a certain modality.

RESULTS

Based on this analysis, the rank order of urodynamic efficacy was that open prostatectomy is more effective in reducing urethral resistance than is transurethral prostatectomy. These treatments diminish obstruction better than laser treatment or transurethral incision of the prostate, which again are more effective than balloon dilation, alpha-blockers or transurethral microwave thermotherapy. Finally, androgen deprivation performs better than placebo treatment.

CONCLUSIONS

The rank order of urodynamic efficacy as determined in this analysis shows a high level of agreement with reported rank order of symptomatic efficacy of various modalities. After placebo treatment there is no significant change in urethral resistance. This finding indicates that pressure-flow studies are a sensitive way to compare active to placebo treatment and that pressure-flow studies have excellent long-term reproducibility.

Pressure-flow study analyses in patients treated with high energy thermotherapy

PURPOSE

We evaluated the urodynamic changes after high energy microwave thermotherapy in patients with lower urinary tract symptoms and benign prostatic enlargement.

MATERIALS AND METHODS

A total of 120 patients was available for analysis with urodynamic investigation and pressure-flow studies before and 6 months after treatment. Several obstruction parameters were used to evaluate treatment outcome.

RESULTS

A significant decrease (p < 0.001) in all obstruction parameters was noted. Mean detrusor pressure at maximum flow decreased from 64.7 to 39.1 cm. water, urethral resistance factor from 41.8 to 23.5 cm. water and linear passive urethral resistance relation from 3.0 to 1.4. Analysis of subgroups showed better results in patients with greater degrees of obstruction.

CONCLUSIONS

High energy thermotherapy results in a significant and substantial decrease in bladder outlet obstruction.

High-energy transurethral microwave thermotherapy: a thermoablative treatment for benign prostatic obstruction

OBJECTIVES

High-energy transurethral microwave thermotherapy (TUMT) was developed to increase treatment efficacy over former low-energy treatment protocols as an outpatient-based, anesthesia-free procedure for patients with benign prostatic obstruction. A Phase II study was conducted to evaluate treatment outcome and to enlighten possible prognostic factors.

METHODS

Eighty-five patients with lower urinary tract symptoms were included in the study. A Madsen symptom score of 8 or more, a maximum flow less than 15 mL/s, and a postvoid residual urine volume (PVR) of under 350 mL were the main requirements for entry.

RESULTS

Eleven patients were lost to follow-up, making 74 patients evaluable at 1-year follow-up. Significant improvement was noticed in all indices: the Madsen symptom score improved 58% from baseline; the maximum flow rate improved from 9.4 to 14.9 mL/s, with a decrease in PVR of 80 mL to 25 mL; bladder outlet obstruction could be relieved in 78% of patients; and prostate volume decreased by 20%, with cavity formation in 42% of patients. Patients with bigger prostates (greater than 40 cm3) and patients with more severe bladder-outlet obstruction appeared to be the best responders. Post-treatment morbidity consisted of a prolonged need for transurethral catheter drainage (mean 16 days), with correlated irritative voiding complaints for an average of 2 to 3 weeks.

CONCLUSIONS

Overall improvement of high-energy thermotherapy now shows comparable results to surgical resection of the prostate.

Urodynamic assessment in the laser treatment of benign prostatic enlargement

OBJECTIVE

To determine if bladder outlet obstruction can be adequately relieved after laser prostatectomy.

PATIENTS AND METHODS

Since November 1992, a total of 105 patients underwent laser treatment of the prostate because of complaints related to benign prostatic enlargement (BPE). To date, urodynamic data from a study of pressure flow analysis are available for 79 patients both at baseline and at 6 months after treatment. Patients were evaluated using changes in symptoms (IPSS symptom score), peak flow rate (Qmax), post-voiding residual volume (PVR), detrusor pressure at maximum flow (Pdet at Qmax), and the linear passive urethral resistance relation (LPURR). Moreover, patients with minimal bladder outlet obstruction were compared to patients with severe bladder outlet obstruction.

RESULTS

There was a significant improvement in mean IPSS score from 21.3 at baseline to 5.3 at the 6-month follow-up. The Qmax improved from 7.9 mL/s to 17.8 mL/s, and the PVR decreased from 91.6 mL to 15.6 mL. At baseline, > 80% of the patients were considered obstructed according to the analysis of pressure flow, whereas 6 months after laser treatment, only 5% of the patients were still considered obstructed. A comparison of the outcome between minimally obstructed patients and severely obstructed patients showed comparable improvements.

CONCLUSION

Laser therapy of the prostate was, according to urodynamic parameters, capable of relieving outlet obstruction and minimally obstructed patients also showed a significant relief of outlet obstruction.