Effects of catheter size on urodynamic measurements in men undergoing elective prostatectomy

Thirty men undergoing prostatectomy for symptoms of bladder outflow obstruction and low measured maximum flow rates (20 before and 10 after operation) were studied by means of urodynamic investigation. Paired studies were performed on each patient using a large catheter assembly (4 and 10 F) and a small catheter assembly (epidural line, outside diameter 1.1 mm). The order in which the studies were performed was varied randomly. Detrusor pressure at maximum flow rate was significantly greater in the large catheter study (73 +/- 30 cm H2O) than in the small catheter study (65 +/- 27 cm H2O; P less than 0.003). The maximum flow rate was significantly smaller in the large catheter study (8.9 +/- 9.5 ml/s) than in the small catheter study (12 +/- 7 ml/s; P less than 0.001). The increase in detrusor pressure at maximum flow that was noted during the large catheter study was confirmed in the 20 men who were studied before prostatectomy (mean increase 11 +/- 11 cm H2O; P less than 0.001) but no difference was found between the two methods in the 10 men studied after prostatectomy (50 +/- 19 cm H2O and 49 +/- 15 cm H2O). Using a large catheter assembly to perform urodynamic investigations has the advantage that repeated studies can be performed without recatheterisation, but it has the disadvantage of producing a small increase in detrusor pressure at maximum flow in men with symptoms of bladder outflow obstruction. Few errors in diagnosis should result, however, if laboratories using such catheters are aware of this effect and establish their own limit of normal for voiding pressures.     

De novo detrusor underactivity after laparoscopic radical prostatectomy

Objective: The aim of this study was to investigate bladder function following laparoscopic radical prostatectomy, with a focus on de novo detrusor underactivity. Methods: Records on pre‐ and postoperative urodynamic studies were retrospectively investigated in 110 patients who underwent laparoscopic radical prostatectomy. Patients exhibiting de novo detrusor underactivity were selected on the basis of an overt strain voiding pattern during the postoperative pressure flow study with detrusor pressure at a maximum flow rate <10 cm H₂O accompanied by an increase in abdominal pressure. In these patients, a follow‐up urodynamic study was performed to assess subsequent long‐term changes in the bladder function. Results: Of the 110 patients, 10 (9.1%) were observed to exhibit de novo detrusor underactivity during the postoperative urodynamic study. During the voiding phase of the pre‐ and postoperative pressure flow study in these 10 patients, the mean detrusor pressure at maximum flow rate showed a significant decrease postoperatively from 57.6 to 3.0 cm H₂O (P < 0.001), although the mean abdominal pressure at maximum flow rate significantly increased from 23.1 to 102.5 cm H₂O (P < 0.001). The follow‐up urodynamic study performed on seven patients at 36 months following surgery revealed no significant change in each urodynamic parameter. De novo detrusor underactivity persisted even over the long term following surgery, and no improvement in bladder function was observed. Conclusions: Detrusor contractility may be impaired during radical prostatectomy. Postoperative detrusor underactivity following radical prostatectomy seems to be an irreversible phenomenon persisting even over the long term.     

Measurement of voiding pressures on ambulatory monitoring: comparison with conventional cystometry

A series of 20 patients underwent conventional medium fill cystometry (CMG) and ambulatory monitoring during natural bladder filling (AM). The measurement of voiding pressures by the 2 techniques was compared. The maximum subtracted detrusor contraction pressure recorded during CMG (50 +/- 30 cm H2O) was significantly less than that recorded during AM (86 +/- 35 cm H2O). Voiding pressures during natural filling are greater than those observed during conventional urodynamic studies: this finding may have important implications in the definition of bladder outflow obstruction.     

Vesico-ureteral reflux in women with idiopathic high-pressure detrusor overactivity: prevalence,bladder function,and effect on the upper urinary tract

Introduction and hypothesis

To assess the prevalence of vesico-ureteral reflux (VUR) and upper urinary tract damage in women with idiopathic high-pressure detrusor overactivity (IHPDO) and to characterize their bladder function.

Methods

A retrospective chart review of women diagnosed with IHPDO (detrusor pressures > 40 cm H₂O during involuntary bladder contractions) from 2007 to 2010 was conducted. Women were assessed for VUR by X-ray voiding cysto-urethrogram. Renal ultrasound or CT urogram, serum BUN/creatinine, and urinalyses were performed if reflux reached the renal pelvices. Cystometric and voiding pressure study data were reviewed for detrusor overactivity pressure and volume, voiding dysfunction, urethral relaxation, compliance, and bladder outlet obstruction.

Results

Sixty-five women were diagnosed with IHPDO, and 50 completed an X-ray voiding cysto-urethrogram. The median (range) detrusor overactivity pressure was 65 (41–251) cm H₂O. Four (8.0 %) women had IHPDO; none had upper urinary tract deterioration. The majority of women exhibited urethral relaxation with voiding, impaired compliance, and bladder outlet obstruction.

Conclusions

Women with IHPDO are at risk of low-grade vesico-ureteral reflux. However, most women with IHPDO are likely protected from reflux by intermittent exposure to high detrusor pressures and the ability to decompress the bladder by urethral relaxation.     

Pressure/flow studies in elderly men without voiding problems: Estimation of the urethral pressure/flow relation and urethral elasticity

The flow in the urethra is controlled by an elastic constriction, the flow-controlling zone. The distensibility of this zone is described by the pressure/area relation, which gives the static pressure as a function of the cross-sectional area at the flow-controlling zone. The pressure/area relation can be calculated from the pressure/flow relation, which is estimated from the pressure/flow plot obtained at a urodynamic examination. In this study the urethral pressure/flow and pressure/area relations were estimated for 21 randomly selected men (62–75 years old) without voiding problems. Nineteen of 21 persons in this group had pressure/flow relations with a low slope. This corresponds to a low slope in the pressure/area relation indicating high distensibility of the flow-controlling zone, which for 18 persons was estimated to be distended to areas larger than 10 mm² during micturition. Twenty persons had a minimal urethral opening pressure below 55 cm H₂O. The estimated pressure/area relation was linear in 59% of the micturitions, indicating that the flow-controlling zone could have been distended to a larger cross-sectional area, if the bladder had achieved a higher pressure. The 10th–90th percentiles for maximum flow and detrusor pressure at maximum flow were 7.2–24.3 ml/s and 24–76 cm H₂O, respectively. Four persons had low flow and low pressure, indicating diminished detrusor contractility with age. Twenty-four percent of the persons had unstable bladder contractions with a pressure rise < 15cm H₂O and 19% with a pressure rise < 15cm H₂O.     

逼尿肌收缩压测定在BPH患者术后疗效评估中的意义

目的 探讨逼尿肌收缩压测定在BPH患者术后疗效评估中的应用价值.方法 BPH患者109例.年龄62～83岁,平均71岁.均行尿动力学检查,明确诊断BOO,排除神经、内分泌以及其他系统疾病因素.根据逼尿肌收缩情况分为2组:Ⅰ组为逼尿肌亢进型61例,逼尿肌收缩压≥40 cm H2O(1 cm H2O=0.098 kPa),单纯行TURP或开放手术;Ⅱ组为逼尿肌无力型48例,逼尿肌收缩压≤20 cm H2O,同期行TURP和膀胱造瘘术,术后持续开放造瘘管至少2周.统计学比较2组患者术后1、3个月逼尿肌收缩压、Qmax和残余尿等参数.结果 2组患者术前最大逼尿肌收缩压分别为(78.4±37.0)、(19.2±5.4)cm H2O,Qmax分别为(7.6±2.2)、(2.5±1.1)ml/s,组间差异均有统计学意义(P＜0.05);术后1个月Qmax分别为(17.4±2.9)、(12.5±2.0)ml/s,组间差异有统计学意义(P＜0.05);术后3个月Qmax分别为(18.3±2.8)、(15.2±1.8)ml/s,组间差异无统计学意义(P＞0.05).结论 BPH患者BOO解除后,收缩乏力状况可以逐渐恢复,Qmax能获得改善,对合并逼尿肌收缩无力患者积极手术解除梗阻,可促进逼尿肌功能恢复.

Abstract：

Objective To study the value of the preoperative detrusor contractility to the outcome assessment of prostatectomy for benign prostatic hyperplasia (BPH).Methods A total of 109 patients with BPH were analyzed.Their ages ranged from 62 to 83 years with a mean of 71 years.All patients underwent urodynamic study to confirm a diagnosis of BOO preoperatively.Further more, their BOO was not caused by nervous, endocrine or other diseases.Pateints were divided into two groups based on maximum detrusor contractility.Group Ⅰ (n =61, BPH with maximum detrusor contractility ≥ 40 cm H2O, 1cm H2O =0.098 kPa) underwent TURP or open surgery, respectively.Group Ⅱ (n =48, BPH with maximum detrusor contractility ≤ 20 cm H2O ) underwent TURP and suprapubic punctural cystostomy simultaneously,the bladder fistula was kept open continuously for at least two weeks postoperatively.The difference in outcome between the two grous was assessed by using urodynamic parameters including maximum detrusor contractility, Qmax and residual urine at one and three months postoperatively respectively.Student's t-test was used to compare the result for normally distributed data and Wilcoxon's signed-ranks test for skewed data in this study.Results There was significant difference in preoperative maximum contractility, Qmax between group Ⅰand groupⅡ (78.4 ±37.0 cm H2O) vs (19.2 ±5.4 cm H2O)(P＜0.01), (7.6±2.2 ml/s) vs (2.5 ± 1.1 ) ml/s (P ＜ 0.05) respectively.Although there was significant difference at one month postoperatively in Qmax (17.4 ±2.9)ml/s vs (12.5 ±2.0)ml/s (P＜0.05), no significant difference was found in Qmax between the two groups after three months ( 18.3 ±2.8 ml/s) vs ( 15.2 ± 1.8)ml/s (P ＞ 0.05).Conclusions The Qmax may improve and the impaired detrusor recovered gradually after the BOO was removed.Performing an operation on patients with BOO accompanied with detrusor underactivity may be useful to recover detrusor contractility.     

Maximal bladder capacity is a positive predictor of response to desmopressin treatment in patients with MS and nocturia

Objective The aim of the study is to evaluate the efficacy of desmopressin therapy in the symptomatic treatment of nocturia in patients with multiple sclerosis (MS) and neurogenic detrusor overactivity, and to investigate the validity of maximal bladder capacity as a predictor of response to intranasal desmopressin inhalation. Material and methods A set of 20 women with MS and neurogenic detrusor overactivity enrolled in a prospective pilot study and were divided into two groups: Group A, the large bladder capacity group (maximal bladder capacity >250 ml, compliance >20 ml/cm H₂O, n = 10) and Group B, the small bladder capacity group (maximal bladder capacity <250 ml, compliance <20 ml/cm H₂O, n = 10). Maximal bladder capacities were measured by urodynamic evaluation. The dosage selected for the study was based on the established dose of commercially available desmopressin nasal spray (20 μg before bedtime) and on clinical trial experience. All patients were monitored for arterial blood pressure before and after treatment and for weight increase for the first 5 days of treatment. Night time voiding diaries were maintained for the 6 weeks of the trial; similarly, serum electrolyte levels and urine osmolality were measured twice weekly during the trial. Results The mean volume of nocturnal incontinence decreased significantly in both groups (P < 0.005). The average number of episodes of nocturia per night in Group A decreased from 2.35 to 0.89 and in Group B from 2.31 to 1.65. The maximum hours of sleep uninterrupted by nocturia increased from 2.54 to 4.62 in Group A and from 2.45 to 3.23 in Group B. Side effects were infrequent; only 2 patients complained of transient headaches. Neither hyponatremia nor serum electrolyte abnormalities occurred. Conclusions Our results suggest that desmopressin is effective in the symptomatic management of nocturia in patients with MS and neurogenic detrusor overactivity. Maximal bladder capacity is a valuable predictor of response to desmopressin.     

Magnetic stimulation of the sacral roots

Magnetic stimulation using an external surface coil induces an electrodynamic field that penetrates various tissues and stimulates peripheral nerves in a similar fashion to conventional electrical stimulation. An 83 mm magnetic surface coil was used to stimulate 11 spinal cord injury (SCI) patients, during which time detrusor activity and evoked potentials of the striated urinary sphincter motor pathways were evaluated. AH patients had urodynamic studies and conventional sacral evoked potentials prior to magnetic stimulation. The mean bladder capacity was 337 ml (range 109–590), mean leak point pressure was 50 cm H₂O (range 10–80), and mean sacral reflex (afferent-efferent) latency was 37.9 ms (range 25.1–49.3). Eight patients had detrusor-sphincter dyssynergia. Magnetic stimulation over the sacral spine at different bladder volumes was performed. Detrusor and striated sphincter responses were recorded during stimulation. In all patients the technique was easy and the results were reproducible. The mean sacral motor pathway (efferent) latency was 27.9 ms (range 18.7–39.6). Using maximal stimulation, no detrusor response was recorded at bladder volumes <200 ml. However, a detrusor response was recorded in 7 patients (>10 cm H₂O in 2, <10 cm H₂O in 5) when the bladder volume was >200 ml. No complications were seen. Sacral evoked potential measurements assess the function and integrity of the sacral arc but it does not distinguish between afferent and efferent pathways. Magnetic stimulation is a safe and effective method to assess the integrity and function of the detrusor and striated sphincter motor (efferent) pathways. When combined with sacral evoked potential studies, the sensory (afferent) pathways can be evaluated indirectly. Independent assessment of the motor (efferent) and sensory (afferent) pathways of the sacral arc has significant implications in the understanding of the pathophysiology of the different types of neuropathic voiding dysfunction. The magnitude of the detrusor contraction induced by magnetic stimulation was too small to allow any conclusions. However, it appears that the detrusor threshold for stimulation increases with increased bladder volumes.     

The comparative pressure‐flow plot properties of radiological bladder neck and prostatic obstruction

OBJECTIVES

To test the hypotheses that: (i) significant differences should exist in pressure/flow data between radiologically determined bladder neck and prostatic obstruction; (ii) these differences should inform understanding of the pathophysiology of male outflow obstruction. The biomechanics of the voiding/pressure/flow plot imply that a urodynamic assessment trace should identify outflow obstruction and characterise the urethral viscoelastic properties. Micturating cystourethrograms (MCUG) images might provide a useful diagnostic dichotomy for testing these assumptions.

MATERIALS AND METHODS

The pressure/flow data from 71 men who also provided video‐urodynamic imaging data that a radiologist could classify unequivocally as showing bladder neck obstruction (42) or prostatic obstruction (29) were analysed. The following variables were recorded: the detrusor pressure at initiation of voiding (P_det.open); the detrusor pressure at the end of voiding (P_det.close); the detrusor pressure at maximum flow rate (Q_max), (P_det.Q_max), and Q_max. The urethral resistance relation (URR) was drawn onto the pressure‐flow plot and the gradient of the URR, ΔP_det/ΔQ, was calculated.

RESULTS

There were significant between group differences in P_det.open (95% confidence interval of the difference 5.2–28.6, U = 352, P = 0.003); P_det.close (0.2–15.0, U = 428, P = 0.034); P_det.Q_max (0.0–18.9, U = 439, P = 0.05); Q_max and ΔP_det/ΔQ did not distinguish between the MCUG groups (95% confidence interval of the difference 2.3–18, U = 111; P = 0.004). The best‐fit model from linear combinations of the data achieved an area under the receiver operator curve of 0.72 for discriminating between the MCUG groups.

CONCLUSIONS

The urodynamic assessment identified interesting and coherent biomechanical differences, and could distinguish between the obstructions with a moderate degree of accuracy.     

Chronology and urodynamic characterization of micturition in neurohormonally induced experimental prostate growth in the rat

The purpose of this study was to evaluate the impact of chronic urinary tract obstruction which was produced in the rat using neurohormonally induced experimental prostate growth. In this model, we considered the chronology of changes in the micturition characteristics of awake rats relative to prostate weight and stiffness. The corresponding urodynamic characteristics of both the upper and lower tracts were evaluated in anesthetized animals relative to the development and extent of the obstruction produced. Prostate growth was produced by capitalizing on the synergistic properties afforded by the combined administration of dihydrotestosterone propionate (DHT) and the α1 adrenoreceptor antagonist prazosin (PRZ). DHT (1.25 mg/kg/day) was dissolved in 0.1 ml sesame oil (SO) and coadministered with PRZ 30 μg/kg/day subcutaneously for 14 days to 12 experimental rats. SO alone was given to 8 control rats. Micturition studies were first performed using all 20 awake rats, which were placed unrestrained in metabolic cages. Urodynamics of the upper and lower urinary tracts were repeated following anesthesia at the 5th, 10th, and 15th weeks after initiation of hormonal or SO treatment. Following the urodynamic studies, the rats were killed and prostates were removed and weighed, and stiffness was measured. Studies with awake rats show that hormonal treatment produces a significant and progressive increase in mean frequency of micturition, ranging from 0.63 ± 0.16 in controls and reaching the maximum of 2.15 ± 0.40/hr by the 10th wk. Results from urodynamic studies with anesthetized rats also show typical and progressive obstructive characteristics: maximum detrusor voiding pressure (P_detmax) increased from 52.7 ± 2.03 in controls to a maximum of 77.5 ± 2.2 cm H₂O by the 10th week; urethral opening pressure P_uo likewise increased from 52.6 ± 2.7 in controls to 73.3 ± 2.1 cm H₂O in experimental rats. The duration of time during which the detrusor sustains contraction during voiding also rose, from 16.8 ± 1.8 sec in controls to 32.0 ± 3.2 sec by the 10th week. There were no significant changes in bladder capacity, baseline filling pressures, or arterial pressures. Prostate weight increased significantly from 0.76 ± 0.05 g in controls to 1.17 ± 0.1 g by the 15th week. Similarly, stiffness increased from control values of 1.33 ± 0.18 g/cm to a maximum of 3.59 ± 0.14 g/cm by the 10th week. It is concluded that neurohormonally stimulated prostate growth in the rat is a suitable animal model for the study of the development of urinary tract obstruction. Obstructive characteristics were validated in both awake rats by the increase in the frequency of micturition and urodynamically under anesthesia in terms of elevations in maximum detrusor pressures, urethral opening pressure, detrusor contraction time, and prostatic stiffness. The effect of obstruction was further shown to be associated with vesicoureteral reflux during micturition and elevated upper tract pressures. Neurourol. Urodyn. 17:55–69, 1998. © 1998 Wiley-Liss, Inc.     

Variability of Pressure-Flow Analysis Parameters in Repeated Cystometry in Patients with Benign Prostatic Hyperplasia

Urodynamic investigation becomes increasingly important in the diagnosis of bladder outflow obstruction in patients with benign prostatic hyperplasia. To date, different methods for evaluation of the pressure-flow relationship and quantification of the grade of obstruction are available. Models for pressure-flow analysis are briefly explained.The variability of the parameters is investigated by evaluation of 75 patients in whom 2 sequential voidings during urodynamic investigation were analyzed. The results showed that in 87 percent of these patients individual maximum flow differences of first and second voidings were less than 2 ml. per second. Individual detrusor pressure at maximum flow differences were less than 15 cm. water in 80 percent of these patients, while in 80 percent the intra-individual variation of the pressure-flow results was less than 15 cm. water for the minimal voiding pressure parameters (minimal urethral opening detrusor pressure and urethral resistance factor). For the pressure-flow parameter that defines the theoretical urethral lumen during voiding, the variation was less than 1.5 mm.² in 84 percent of the patients. Patients with larger intra-individual differences are discussed. We concluded that the observed, aforementioned differences can be regarded as an indication of normal intra-individual variability of voiding during urodynamic investigation. This intra-individual variability, however, seldom leads to a change in the clinical grade of bladder outflow obstruction. We conclude that investigators involved in therapeutic trials of benign prostatic hyperplasia must be aware of this intra-individual variability of micturition, since this variability is greater than the refined scale of the pressure-flow analysis models.     

The bladder neck in neurological degenerative disorders

Bladder neck incompetence occurs frequently in the Shy-Drager syndrome. The behavior of the bladder neck in patients with multiple sclerosis and Parkinson's disease, however, has not been well defined. Complete urodynamic studies were performed on 48 patients with urgency incontinence and one of the following neurological diagnoses: Parkinson's disease (13 patients), Shy-Drager syndrome (13 patients), and multiple sclerosis (22 patients). Complete studies were also performed on 73 patients with no neurological diagnoses and no incontinence. None of the patients had ever undergone prior transurethral surgery. All patients with a neurological diagnosis had detrusor hyperreflexia on cystometrogram. Bladder neck function was evaluated with fluoroscopy as well as with intraluminal-pressure measurements utilizing a 10 French triple-lumen catheter. Only 11 (22%) of the neurological patients had an incompetent bladder neck on fluoroscopy (6 with Shy-Drager, 3 with Parkinson's, and 2 with multiple sclerosis). Mean bladder neck pressures of the 48 neurological patients were as follows: Parkinson's: 12 cm H₂O, SE = 5; multiple sclerosis: 15 cm H₂O, SE = 1.2; and Shy-Drager: 7 cm H₂O, SE = 2. Bladder neck incompetence, commonly seen in Shy-Drager and strongly suggestive of sympathetic dysfunction, is uncommon in incontinent patients with other degenerative neurological disorders and detrusor hyperreflexia.     

Transurethral incision of the prostate and bladder neck for the treatment of outflow obstruction caused by a small benign prostate]

Transurethral incision of the prostate and bladder neck (TIPBn) was compared with transurethral resection of the prostate (TURP) followed by bladder neck incision in the treatment of 22 patients with outflow obstruction caused by a small prostate adenoma (below 15 gm). Eleven patients underwent TIPBn and another 11 TURP. An evaluation of the urodynamic findings and subjective symptoms was undertaken before the operation and 3 months afterwards. Urodynamic findings were evaluated, based upon uroflowmetry, i.e., in terms of maximum flow rate, average flow rate, voiding time, initiation time and residual rate. All patients in the TIPBn group revealed an improvement in every urodynamic parameter (MFR: from 6.1 to 10.8 ml/sec, AFR: from 3.1 to 5.8 ml/sec, Voiding time: from 95.5 to 24.2 sec/100 ml, Initiation time: 34.3 to 10.2 sec, Residual rate: 31.6 to 17.8%, in mean value). Ten out of the 11 in the TIPBn group subjectively considered the result to be good. The improvements in the urodynamic parameters in the TIPBn group were statistically comparable to those in the TURP. The improvements in voiding time and initiation time, however, tended to be much better in the TIPBn group. We conclude that TIPBn can be the operation of choice in the treatment of outflow obstruction caused by a small prostate.     

Diagnosing bladder outlet obstruction in women

PURPOSE: There are no universally accepted urodynamic criteria for diagnosing female bladder outlet obstruction. When accepted criteria for men are applied to women, the diagnosis of obstruction may often be missed, which is most likely due to differences in voiding dynamics. We propose video urodynamic criteria for diagnosing obstruction in women, and describe the urodynamic findings in those with and without obstruction. MATERIALS AND METHODS: We reviewed the charts of 331 women who underwent multichannel video urodynamics for nonneurogenic voiding dysfunction. Of these women 261 (mean age 55.8 years) had evaluable voiding pressure flow studies with simultaneous video fluoroscopy of the bladder outlet during voiding. At video urodynamics cases were classified as obstructed if there was radiographic evidence of obstruction between the bladder neck and distal urethra in the presence of a sustained detrusor contraction. Strict pressure flow criteria were not used. Maximum flow rate, detrusor pressure at maximum flow rate, post-void residual, bladder capacity and the incidence of detrusor instability were compared between obstructed and unobstructed cases. RESULTS: A total of 76 women met the criteria for obstruction (mean age 57.5 years), while 184 (mean age 55) did not. Causes of obstruction were dysfunctional voiding in 25 cases, cystocele in 21, primary bladder neck obstruction in 12, iatrogenic from incontinence surgery in 11, urethral stricture in 3, uterine prolapse in 2, urethral diverticulum in 1 and rectocele in 1. Obstructed cases had lower mean maximum flow rate (9 versus 20.2 ml. per second, p <0.0001), higher mean detrusor pressure at maximum flow rate (42.8 versus 22.1 cm. water, p <0.0001) and higher mean post-void residual (157 versus 33 ml., p <0.0001). There was no difference in bladder capacity (381 versus 347 ml.) or incidence of detrusor instability (45 versus 41%). CONCLUSIONS: Using the proposed video urodynamic criteria obstructed cases had significantly higher voiding pressures, lower flow rates and higher post-void residual than unobstructed cases, as expected. However, absolute values, especially for voiding pressure, are not as dramatic in women as in men. Pressure flow studies alone may fail to diagnose obstruction but simultaneous imaging of the bladder outlet during voiding greatly facilitates diagnosis.     

Preoperative voiding detrusor pressures do not predict stress incontinence surgery outcomes

Introduction and hypothesis

The aim of this study was to determine whether preoperative voiding detrusor pressures were associated with postoperative outcomes after stress incontinence surgery.

Methods

Opening detrusor pressure, detrusor pressure at maximum flow (p _det Q_max), and closing detrusor pressure were assessed from 280 valid preoperative urodynamic studies in subjects without advanced prolapse from a multicenter randomized trial comparing Burch and autologous fascia sling procedures. These pressures were compared between subjects with and without overall success, stress-specific success, postoperative detrusor overactivity, and postoperative urge incontinence using independent sample t tests.

Results

There were no clinically or statistically significant differences in mean preoperative voiding detrusor pressures in any comparison of postoperative outcomes.

Conclusions

We found no evidence that preoperative voiding detrusor pressures predict outcomes in women with stress predominant urinary incontinence undergoing Burch or autologous fascial sling procedures.     

Interrelationships of bladder compliance with age, detrusor instability, and obstruction in elderly men with lower urinary tract symptoms

Data on the interrelationships of bladder compliance (BC), detrusor instability (DI), and bladder outflow obstruction (BOO) in elderly men with lower urinary tract symptoms (LUTS) are scarce and were therefore assessed in this study. Principle inclusion criteria for this study were men aged > or = 50 years suffering from LUTS as defined by an International Prostate Symptoms Score (IPSS) of > or = 7 and a peak flow rate (Qmax) of < or = 15 ml/sec. Patients with previous surgery of the bladder, prostate, or urethra as well as a pathological neurourological status were excluded from this study. The following parameters were studied in all patients: IPSS, prostate volume calculated by transrectal ultrasonography, free uroflow study, post-void residual volume determined by transurethral catheterization, and a multichannel pressure flow study (pQS). A group of 170 men were included in the analysis. The mean BC in the overall group was 32 +/- 2 ml/cm H2O (mean +/- standard error of the mean [SEM]; range, 4-100 ml/cm H2O). In 36.5% of patients, BC was significantly reduced (< or = 20 ml/cm H2O), and in a further 37.1%, it ranged from 20 to 40 ml/cm H2O. BC decreased statistically significantly (p < 0.05) in patients with advanced age, lower Qmax, higher voiding pressures, and larger prostates. In men with DI (n = 61), mean BC was significantly lower (22 +/- 3 ml/cm H2O) compared to those without (37 +/- 3 ml/cm H2O; p = 0.001; n = 109). Patients with severe BOO as defined by a linear passive urethral resistance relationship of > or = 3 (n = 109), had a significantly lower BC (23 +/- 2 ml/cm H2O) compared to those without or minimal obstruction only (39 +/- 3 ml/cm H2O; p = 0.0002; n = 61). Stepwise logistic regression analysis revealed that DI, a low bladder capacity, and a high maximum detrusor pressure were independent predictors of markedly reduced BC (< 20 ml/cm H2O). BC is decreased in elderly men with high voiding pressures, BOO, and DI. The mechanism leading to the reduction of BC under these circumstances is largely unknown and could result from cytostructural alterations of the detrusor and changes in detrusor innervation.     

Neurogenic bladder in lower motor neuron lesion: Long-term assessment

We have comprehensively investigated 10 patients with lower motor neuron (LMN) lesions (mean duration of lesions: 14 years) who were managed with intermittent catheterization. All patients (9 males and 1 female) underwent complete neurologic examination and, if necessary, extensive electromyographic studies to define the level and completeness of the lesion. The causes of the LMN lesions were traumatic injury (5), congenital (2), inflammation (1), and surgery (2). Patients were arranged into 2 groups. Five patients had complete lesions (no sensory or motor function at sacral level) and 5 had incomplete lesions (some remaining function). All patients were continent between catheterizations. A detailed urodynamic investigation, including cystometrogram (CMG), urethral pressure profile (UPP), voiding cystourethrogram (VCUG), phentolamine (5 mg i.v.), and bethanechol (5 mg s.c.), Tests, was performed in all patients. Detrusor compliance (DC) at 100 ml was statistically the same in both groups (21.9 ml/cm H₂O in complete lesions and 37.2 ml/cm H₂O in incomplete lesions) and did not change at all after phentolamine in incomplete lesions (37.2 ml/cm H₂O) but was somewhat increased in complete ones (27.5 ml/cm H₂O). Bethanechol decreased DC in patients with complete and incomplete lesions (2.9 and 7.1 ml/cm H₂O, respectively). Maximal urethral pressure was the same in both groups before and after pharmacological tests. The bladder neck was completely closed (VCUG) in all 5 patients with incomplete lesions in comparison to only 1 from the other group. Phentolamine had only a slight effect on bladder neck in both groups. Bladder compliance is normal in patients with LMN lesions treated with intermittent catheterization and the bladder neck is opened only in complete lesions. This may also account for the absence of incontinence in these patients.     

Herpes zoster-associated acute urinary retention: a case report

An 87-year-old woman presents with a 4-week history of urinary incontinence during which she had been treated for disseminated herpes zoster virus (HZV). On physical exam painful vesicles involving the entire vulvar region with mainly right sacral distribution were found. A catheterized volume exceeded 600 ml of retained urine after the patient failed to void spontaneously. Multichannel voiding-pressure urodynamic studies revealed an acontractile neurogenic bladder with overflow incontinence. The patient was discharged on a conservative regimen with arrangement for visiting nurse services to perform intermittent self-catheterization twice daily. Urodynamic testing was repeated 10 weeks after initial symptoms. During voiding cystometry a biphasic increase in detrusor pressure of 15 cm H₂O was observed with no increase in abdominal pressure. The patient emptied 400 ml with a postvoid residual of 300 ml. Recovery from HZV-associated bladder emptying dysfunction can be achieved usually through conservative management, including intermittent self-catheterization. Complete recovery time ranges from 4 to 10 weeks.     

Urodynamic effects of α1-blocker tamsulosin on voiding dysfunction in patients with neurogenic bladder

BACKGROUND: The therapeutic role of alpha-blockers in the treatment of voiding disorders due to benign prostatic hyperplasia has been extensively examined. To investigate a possible effect of alpha1-blocker on urodynamic voiding parameters in patients with neurogenic bladder, we conducted a clinical trial using tamsulosin. METHODS: Twenty-four patients (14 men and 10 women) ranging from 24 to 82 years of age (mean age 61 years) with neurogenic bladder were analyzed. Urodynamic studies were performed before and after treatment with 0.4 mg tamsulosin daily for 4 weeks. RESULTS: On uroflowmetry, the average flow rate (from 4.6 +/- 3.3 to 6.7 +/- 3.0 mL/s, P = 0.04), maximum flow rate (from 9.4 +/- 6.8 to 14.1 +/- 7.0 mL/s, P = 0.016) and residual urine rate (from 46 +/- 29 to 32 +/- 21%, P = 0.02) improved significantly. In patients with detrusor contraction during voiding, detrusor opening pressure and detrusor pressure at maximum flow decreased significantly from 69.0 +/- 36.2 to 49.2 +/- 26.4 cmH2O (P = 0.046) and from 66.7 +/- 34.6 to 53.6 +/- 26.5 cmH2O (P = 0.007), respectively. On the other hand, in patients with detrusor areflexia, vesical opening pressure (from 78.2 +/- 23.4 to 61.6 +/- 25.2 cmH2O), or vesical pressure at maximum flow (from 68.6 +/- 23.2 to 62.9 +/- 25.2 cmH2O) did not change significantly after treatment. CONCLUSION: Tamsulosin reduces functional urethral resistance during voiding and improves flow rate in patients with neurogenic bladder. It has more beneficial urodynamic effects in patients with detrusor contraction during voiding than in patients with detrusor areflexia.     

Creation of a feline model of obstructive uropathy

The aim of this project was to create a reproducible, quantifiable feline model of obstructive uropathy. Seventy-three adult female cats of comparable age were evaluated to obtain the normal control urodynamic data base. Twenty-four cats had a silastic cuff installed around the urethra to induce bladder outlet obstruction, and eight underwent a sham operation. Repeated urodynamic evaluations were performed at predetermined postoperative intervals. The obstructed and normal cats inhibited detrusor contractility by reflex striated urethral sphincter activity. Measurements of voiding pressure to verify the presence, and to assess the degree of induced outlet obstruction, required paralysis of the sphincter by curare. Following cuff implantation, voiding pressure increased from a mean normal of 17.2 cm./H2O to 31.6 to 42.5 cm./H2O in animals designated as moderately obstructed, and to 101.7-125.0 cm./H2O in animals designated as severely obstructed. 84.6% of the high pressure bladders developed vesicoureteral reflux. Analysis of resting, low bladder volume, urethral pressure profile (UPP) data and voiding pressures indicate a compensatory sphincteric response to filling in non-curarized animals, and a lack of that response in curarized animals. It appears that implantation of a silastic cuff to prevent full opening of the urethra during voiding, without actually compressing it, is a reasonable model of obstructive uropathy. The observation that the relationship between striated urethral sphincter activity and inhibition of detrusor contractility is influenced by administration of curare was unexpected, and may have clinical implications.