Detrusor contraction strength in men undergoing prostatectomy

Impact of Detrusor Underactivity on Surgical Outcomes of Laser Prostatectomy: Comparison in Serial 12-Month Follow-Up Outcomes Between Potassium-Titanyl-Phosphate Photoselective Vaporization of the Prostate (PVP) and Holmium Laser Enucleation of the Prostate (HoLEP)

OBJECTIVE

To evaluate impacts of preoperative detrusor underactivity (DU) on outcomes of photoselective vaporization of the prostate (PVP) or holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia, and to compare them between the two surgeries.

MATERIALS AND METHODS

A total of 1423 men, who underwent PVP (group A) or HoLEP (group B), were categorized into four groups: A1 (239 without DU), A2 (432 with DU), B1 (329 without DU), and B2 (423 with DU). DU was defined as bladder contractility index of <100. Outcomes were assessed at 1, 3, 6, and 12 months postoperatively using International Prostate Symptom Score (IPSS), uroflowmetry, and prostate-specific antigen. Successful outcome was defined as reductions by ≥50% of total IPSS at 12 months postoperatively.

RESULTS

In all four groups, almost all parameters of IPSS and uroflowmetry improved starting from 1 month. A1 or B1 had greater increases in maximum flow rate than A2 or B2. Decreases of total IPSS in A2 were less than in A1 starting from 1 month after PVP, whereas those in B2 were less than those in B1 as late as 12 months after HoLEP. B2 showed greater improvements in maximum flow rate, subtotal voiding symptom score, bladder voiding efficiency, and total IPSS than A2. In all patients, multivariate regression analysis revealed that the absence of DU, presence of bladder outlet obstruction, and higher baseline total IPSS were independent predictors of successful outcome after surgery, but the type of laser surgery (PVP vs HoLEP) was not.

CONCLUSION

Our data suggest that micturition symptoms, maximum flow rate, bladder voiding efficiency, and quality of life improve starting from the early period after PVP or HoLEP, irrespective of DU. However, patients with DU may have less degree of improvement in micturition after PVP or HoLEP than those without DU.

Maximum isometric detrusor pressure to measure bladder strength in men with postprostatectomy incontinence

OBJECTIVE

To describe the use of isovolumetric detrusor pressure (Piso) in men with postprostatectomy incontinence and compare the rates of detrusor underactivity using Piso versus other common measurements/surrogates of bladder strength.

METHODS

We evaluated 62 men referred to our institution during a 3-year period for workup of postprostatectomy incontinence. During videourodynamic evaluation, the maximum Piso was measured using a mechanical stop test--with the examiner gently occluding the penile urethra during volitional voiding. Statistical analysis was performed to evaluate the effect of patient variables on Piso.

RESULTS

The mean Piso was 54.6 ± 25.4 cm H(2)O. The Piso was <50 cm H(2)O in 40%. Isometric strength did not significantly correlate with age, interval since radical prostatectomy, abdominal leak point pressure, maximal urethral closure pressure, or pad use. The bladder contractility index and other approximations of detrusor underactivity were not predictive of low isometric pressure.

CONCLUSION

Detrusor underactivity is relatively common in men with postprostatectomy incontinence, with 40% demonstrating a Piso <50 cm H(2)O. Our data do suggest, however, that the use of common bladder contractility nomograms, such as the bladder contractility index, might not be appropriate in this population.

Analysis of the Pressure-Flow Study in Weak Detrusor Patients with Benign Prostatic Hypertrophy

OBJECTIVE

Pressure-flow study is a method used to evaluate the degree of bladder outlet obstruction and the strength of detrusor contractility during voiding. However, whether or not the operation for benign prostate hyperplasia should be avoided in detrusor underactivity patients remains controversial. To address this, we performed a retrospective analysis of our pressure-flow study data for benign prostate hyperplasia patients. We especially focused on the backgrounds of patients with weak detrusor contractility.

METHODS

Patients (n = 288; average age, 71.5 years) who underwent pressure-flow study to evaluate operative indications between February 2001 and April 2010 were included in this study. We analyzed the relationships between background factors and detrusor contraction strength according to Schäfer's nomogram.

RESULTS

Patients with weak detrusor contractility had poor flow (5.81 mL/sec) and low voided volume (141.2 mL) compared to patients with normal (8.77 mL/sec, 202.0 mL) or strong (8.97 mL/sec, 178.3 mL) detrusor contractility. Twenty-six of 74 weak detrusor patients underwent prostate operation. The operated group had high obstruction grade (3.35, P < 0.001), but a low rate of detrusor overactivity (19.2%, P < 0.05), compared to the non-operated group (2.16, 41.7%). The operated group also had high urinary retention rate (38.5%) compared to the non-operation group (18.8%).

CONCLUSION

We performed prostate surgery in patients who had episodes of urinary retention, with outlet obstruction, and with no detrusor overactivity, even in those with weak detrusor contractility. The operation may not be contraindicated for these patients. Pressure-flow study is an important tool to ensure adequate informed consent.

Is the short-term outcome of transurethral resection of the prostate affected by preoperative degree of bladder outlet obstruction, status of detrusor contractility or detrusor overactivity?

AIM

The aim of this study was to investigate whether the preoperative degree of bladder outlet obstruction (BOO), detrusor underactivity (DUA) or detrusor overactivity (DO) affected the short-term outcome of transurethral resection of the prostate (TURP) for patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH).

METHODS

Ninety-two patients with LUTS/BPH aged 50 years or older who were considered to be appropriate candidates for TURP were included in this study. Pressure-flow study and filling cystometry were performed to determine BOO, DUA and DO before TURP. The efficacy of TURP was determined at 3 months after surgery using the efficacy criteria for treatment of BPH assessed by the International Prostate Symptom Score, QOL index, maximum flow rate and postvoid residual urine volume.

RESULTS

On preoperative urodynamics, 60%, 40% and 48% of patients showed BOO, DUA and DO, respectively. After TURP, 76% showed 'excellent' or 'good' overall efficacy, whereas only 13% fell into the 'poor/worse' category. The efficacy was higher as the preoperative degree of BOO worsened. In contrast, neither DO nor DUA influenced the outcome of TURP. However, the surgery likely provided unfavorable efficacy for patients having DO but not BOO. Only 20% of the patients who had both DO and DUA but did not have BOO achieved efficacy.

CONCLUSIONS

Transurethral resection of the prostate is an effective surgical procedure for treatment of LUTS/BPH, especially for patients with BOO. DUA may not be a contraindication for TURP. The surgical indication should be circumspect for patients who do not have BOO but have DO.

The relevance of preoperative cystometrography in patients with benign prostatic hyperplasia: correlating the findings with clinical features and outcome after prostatectomy

Preoperative water cystometrograms in 437 patients with benign prostatic hyperplasia (BPH) were examined in a retrospective study. The cystometrographic results were analyzed regarding the preoperative clinical features: patient age, presence or absence of urinary incontinence, history of urinary retention and rate of residual urine. The prognostic value in improvement in voiding difficulty and postoperative urinary incontinence was also analyzed at 1 and 6 months after elective prostatectomy. Subjective symptoms of the patients were the primary reasons for prostatectomy, the majority of which were performed by a single competent resectionist (K. T.) who evaluated the outcome but was blinded to the cystometric findings. Of these patients 263 (60.2%) had detrusor instability (group 1), while 174 did not (group 2). Vesical denervation supersensitivity to bethanechol chloride was noted in 47 of 375 patients (12.5%). The difference in clinical features was significant between the 2 groups, with group 1 showing older patient age (p < 0.01), and a greater incidence of urinary incontinence (p < 0.001) and retention (p < 0.001). The difference between groups 1 and 2 in mean bladder capacity (p < 0.01), compliance (p < 0.01) and a greater positive rate of vesical denervation supersensitivity (p < 0.001) was also significant. The clinical and cystometrographic parameters studied worsened with advancing patient age. Although the majority of the patients (94.7%) were relieved of obstructive symptoms after transurethral prostatectomy (6 months later), 113 (25.9%) were not at 1 month. Compared to 324 patients with early improvement (74.1%), those without improvement at 1 month were characterized by older age (p < 0.01), greater prevalence of preoperative incontinence (p < 0.05), retention (p < 0.01), greater residual rate (p < 0.05), a less compliant bladder (p < 0.01) and a higher positive rate of vesical denervation supersensitivity (p < 0.05). Cystometrographic findings, however, had no relevance to late (6 months) outcome of voiding difficulty. On the other hand, postoperative incontinence was noted in 100 patients (22.9%) at 1 month after transurethral prostatectomy, with the majority having episodes similar to those experienced preoperatively (70.0%) as well as detrusor instability (87.0%). They also were older (p < 0.01), and had a less compliant bladder (p < 0.01) and a higher positive rate of vesical denervation supersensitivity (p < 0.01) than did continent patients. Only 18 elderly patients (4.1%) remained incontinent 6 months later, all with a less compliant (p < 0.01) and more unstable (p < 0.01) bladder initially. The genesis of this detrusor dysfunction was believed to be aging in male patients, in whom BPH evolves and progresses. In conclusion, preoperative cystometrography in patients with BPH is valuable in that it correlated well with the clinical features and it can predict to some extent the outcome of obstructive symptoms and urinary incontinence after transurethral prostatectomy.