TitleDysfunctional voiding in male and f. Citation 泌尿器科紀要 (1983), 29(8):

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Citation 泌尿器科紀要 (1983), 29(8): 1009-1013 Issue Date 1983-08

1 TitleDysfunctional voiding in male f Author(s) Gleason, Donald M. Citation 泌尿器科紀要 (1983), 29(8): Issue Date URL Right Type Departmental Bulletin Paper Textversion publisher Kyoto University

2 1009 racta Urol. Jpn. Vol. 29'1 No. 8, August 1983 DYSFUNCTIONAL VOIDING IN AND FEMALE PATIENTS MALE Biomedical Donald M. GLEASON, M. D. Engineering, College of Engineering, Department College of Medicine, University of Arizona of Surgery, urinary rate is product of area velocity to. For any given rate larger area, slower velocity vice versa. narrowest point of is usually vena contracta, i.e., jet beyond meatus. An intricate mechanism relates bladder pressure, out resistance, rate velocity. Ideally, velocity is directly related to bladder pressure according to formula gp=1/2pv22(1) where g is gravitational constant, P bladder pressure, p density of urine, v velocity (cm/s). However, ideal relationship is never realized in urethra because of energy losses due to viscosity of fluid, friction of fluid walls of urethra etc. Rar, an energy loss term must be introduced energy loss will n be proportional to velocity. Energy Loss (L) =k v2(2) where k= energy loss constant refore gp =1 /2 p (l +k) v2(3) is equation relates bladder pressure urinary velocity. energy loss coefficient describes severity of proximal obstruction can be calculated if bladder pressure velocity are known. Since velocity will reflect bladder pressure energy loss, severe obstruction or hypotonic bladder will reduce velocity sufficiently in relation to rate, se studies can aid in diagnosis assessment of a patient's clinical status out necessity of instrumenting patient. Velocity studies have been used for diagnostic purposes since work of Schwarz Brenner' in y related cast distance of to velocity n to pathology. A more intricate method involved measurement of droplet velocity between two beams of light, as urinary broke down into droplets after leaving meatus2>. I have used dynamometer disc most extensively over last ten years3). This disc measures impact force of urinary voided against it; this impact force equals rate times velocity, also defined as momenturn: F= Qv(4) where F is impact force, Q rate v velocity. rate is measured electronically a gravimetric meter. Parallel force curves are generated from velocity area can be calculated at any point in. v=f/q(5) A=Q/v=Q2/F(6) are two equations relate velocity area of where A is area. Urometry values for a group of normal women is given in Table 1. urinary rate in this group is closely related to volume voided; an observation generally acknowledged in literature. force also relates to volume voided as one might expect since rate is dominant corn-

1010 Acta Urol. Jpn. Vol. 29 No. 8, 1983 Table 1. Mean values of female parameters No. of woman Volume Voided (ml) Maximum Flow Rate (ml/s) Force (GM) At Max. Flow Rate Stream Velocity (cm/s) At Max.

3 1010 Acta Urol. Jpn. Vol. 29 No. 8, 1983 Table 1. Mean values of female parameters No. of woman Volume Voided (ml) Maximum Flow Rate (ml/s) Force (GM) At Max. Flow Rate Stream Velocity (cm/s) At Max. Flow Rate Stream Area At Max. Flow (cmu) Normal Stress Incontinence Voiding Dysfunction Not Instrumented Instrumented ponent of force formulation. In normal female, rate is not related to patient age; it is related to area but not to velocity. In hydrodynamic terms, this relation of rate to exit area is characteristic of a nozzle controlled. By word of explanation, analogy of garden hose is applicable. When is modified by nozzle at its end, is considered to be nozzle controlled, in contradistinction to a proximal constriction when for example spigot is closed. implication of course, is that urinary in females is indeed a nozzle controlled characterized by a zone of constriction distally. More than 100 women urethral syndrome were studied -velocity measurements were compared to normals (see Table 1)4). In women urethral syndrome, i.e., symptoms of frequency, uregency bladder discomfort, about 40% tend to void smaller volumes than ir normal cohorts. Moreover, close relationship between rate volume voided degenerates in women urethral syndrome. rate is still related to area but area of is considerably smaller than that in normal female. Furrmore, area of tends to increase during course of voiding so that area at peak is about 30 to 40 percent greater than that at mean. This relationship between area at mean peak is generally maintained in presence of voiding dysfunction, though absolute value of area is less than normal by a considerable margin. However, if patient has been instrumented, i.e., her urethra has been repeatedly dilated or some sort of urethral "enlarging" procedure has been done, urethra seems to lose some of its capability to exp during peak. result is a area roughly same at peak as it is at mean. This suggests that urethra has become rigid or lost compliance possibly influenced adversely by very instrumentation intended to improve it. Stream velocities in female, as might be expected are not of great clinical interest being similar in both normal subjects patients voiding dysfunction. In fact, separation of patients according to ir urethral procedure (including dilation, meatotomy, urethrotomy, urethroplasty) shows no great difference among m, except for a small group of patients (about 20%) who have benefitted from urethrotomy have rates in normal range. All instrumented patients seem to void at lower rates areas than eir normals or uninstrumented patients. Indeed, much research into mechanism of voiding dysfunction tends to support physiological not a mechanical impediment to voiding in urethral syndrome. Medical treatments ranging from musculotropic agents, anti-cholinergics, prostaglin inhibitors even striated muscle relaxants have been tried varying degrees of success.

Gleason Fig. 1. : Dysfunctional urinary is directed against voiding dynamometer disc measures impact force. urine is voiding Fig. 2.

4 Gleason Fig. 1. : Dysfunctional urinary is directed against voiding dynamometer disc measures impact force. urine is voiding Fig A simple velocity meter was constructed from a light plastic paddlewheel against patient voided. rotation of paddlewheel turned a small ele- directed downwards into a gravimetric urometer. From measured force rate, velocity area can be calculated ctric motor generated an current. voltage generated proportional was easily to measured electric was velocity a small vol- tmeter Women an interesting stress incontinence have pattern5). y voiding tend to void smaller amounts than ir normal cohorts. More likely this represents a habit pattern, born of tendency to leak more freely as bladder fills. However, relationship of rate to volume voided is retained in se women, y tend to void lower rates than normal, mean value for peak lying in region of 21 ml/s (compared to about 28 ml/s for normals ). data is skewed however, about 30% void supernormal values. area closely follows rate is decreased for majority of population of stress incontinent women but may be increased to higher than normal values in few supernormal. An interesting variables: city, in bladder small incontinence area relationship pressure, group of who have of rate, From engineering known that output at high pressure increase its high rates. of constriction resistance reduce reference tion, to a small incontinence than higher urinary power will normal, urethra than pump ory, be expected slows increase a is normal rate With popula- area a result as part will of out- patient occurring rate of women probably by any pressure. present number have tract output removal bladder an bladder mechanisms, Similarly, require lower its fluid a high biochemical pressure. pump would to a high low output. a limit intrinsic out ease. stress pump given raise To in power is or is power into pressure, pressure. it a specific its energy low high velo- is found at at lous convert of pumps four women can fluid ory a pump stress larger of a patu- of ir dis- correspondingly according bladder pressure to fall to subnormal to would levels.

5 1012Acta Urol. Jpn. Vol. 29 No. 8, 1983 velocity, as explained before, relates back to bladder pressure, falls in parallel falling bladder pressure. Thus, re seems to be a paradox: very high rate in absence of a bladder contraction, (or more precisely, in absence of significant bladder pressure). This finding defined as "trapdoor urethra" occurred in about 10% of our group presented high rate low velocity. recognition of such patients could be determined from study of alone out necessity for instrumentation. In contrast to women, men have a quite different hydrodynamics of related to ir urethral anatomy. Whereas women exhibit "nozzle controlled ", i.e., control region of urethra lies distally, in male, constrictive region wher it lies at bladder neck, prostate or membranous urethra, lies in proximal urethra. mechanism limiting rate in male is based on energy losses imposed on by fluid viscosity, turbulence due to local areas of constriction expansion of, wall friction or factors. velocity, measures energy content of is exhausted by se impedimenta to. result is a rate that is closely correlated, not area as in female, but velocity. In fact, area in most males tends to be constant. We studied a group of about 650 males including 120 normals ors benign prostatic hypertrophy, stricture or obstructive conditions. We used a very simple device, a light paddle wheel (Fig. 2) patients voided against to measure velocity. speed of rotation of paddle wheel was proportional to velocity of turned a small electric toy motor generated a voltage proportional to velocity. peak rate was measured a Peakometer, a commer cially available disposable meter. Patients voiding volumes less than 125 ml/s m U Velocity (cm/s) Fig. 3. A plot of individual patient -velocity date points obtained at maximum rate tended to cluster into groups. Normal subjects could be separated from obstructed patients more easily using two discriminants toger than y could using each alone were eliminated from study. relation of rate to volume voided age is already well known6). On or h, velocity is responsive to volume voided only at low volumes, less than 200 ml. At volumes beyond that velocity is volume insensitive. velocity is directly linearly related to rate. Stream velocity decreases advancing age in a linear fashion up to age 55, after it seems to level off. Obstructive disease modifies se relationships. velocity is decreased by obstructive prostatism, for instance, never reaches normal levels despite degree of bladder filling. relationship of velocity to rate in both normal diseased states, is best seen in two dimensional data plots. If rate is plotted against velocity (Fig. 3), patient data points will cluster separating normal subjects from obstructed patients7). Flow velocity toger provide much greater discrimination in separation of patient populations than eir parameter alone.

Title risk patients with urinary retentio. Citation 泌尿器科紀要 (2005), 51(4):

Title risk patients with urinary retentio. Citation 泌尿器科紀要 (2005), 51(4): Title Urethral stent (Angiomed-Memotherm) risk patients with urinary retentio Uchikoba, Takushi; Horiuchi, Kazuta Author(s) Oka, Fumiatsu; Saitoh, Yuka; Tsuboi Taiji Citation 泌尿器科紀要 (2005), 51(4): 235-239