- Email: [email protected]
Spontaneous uroflowmetry in prostatism
SPONTANEOUS UROFLOWMETRY KLAUS M.-E. REGINALD PETER
JENSEN,
M.D.
C. BRUSKEWITZ,
IVERSEN,
PAUL 0. MADSEN,
IN PROSTATISM*
M.D.
M.D. M.D.
From the Section of Urology, William S. Middleton Memorial Veterans Administration Hospital, and Department of Urology, University of Wisconsin, Madison, Wisconsin
ABSTRACTUroflowmetry is a valuable urodynamic screening procedure in selecting patients with prostatism for surgery. A prospective study was undertaken in which patients were selected for transurethral resection of the prostate by means of nonurodynamic data only. All patients underwent extensive urodynamic testing. Fifty-three patients were studied preoperatively, while 38 were examined at three months and 22 at twelve months postoperatively. A weak correlation was noted between maximum flow rate and symptom scores, pressure variables, and minimum urethral resistance. However, classification of patients by groups of high, medium, and low maximum flow rates did not identify groups of patients with less favorable outcome of surgery, i.e., patients with higher flow rates did as well as those with lower flow rates. A clear role for spontaneous uroflowmetry could not be identified in the preoperative evaluation of patients with prostatism.
Measurement of the voiding stream has had a prominent place in evaluating disorders of the lower urinary tract. The first uroflowmeters were developed in 1897 by Rehfisch’ and in 1925 by Grijnval. 2 After the description of Drake’s apparatus in 194S3 von Garrelts4 and Kaufman5 developed more sophisticated electronic devices in 1956 and 1957, and uroflowmeter development accelerated. The most useful flow variable in prostatism has been the maximum flow rate (Qmax), which decreases with advancing patient age and increases with increasing vo1ume.6-10 The volumeflow relationship has been mathematically described as a straight line and as hyperbolic and parabolic curves. When Qmax is plotted against the square root of the volume, the graph approximates a straight line,“-I3 implying that the ratio Qmax/dvolume is constant, and consequently that a minimal acceptable volume of *Research supported in part by Veterans Administration
UROLOGY
/ OCTOBER
1984
150 ml is not crucial. This fact is especially important in patients with uninhibited detrusor contractions resulting in small functional bladder capacity. The volume considered should be bladder volume rather than voided volume because the latter, in the presence of residual urine, will lead to overestimation of voiding ability. l l In patients with prostatism uroflowmetry has been found to be valuable as a simple, noninvasive procedure in both pre- and postoperative evaluation.10.14,‘5 For prostatism current dogma holds that patients with Qmax > 15 ml/set are nonobstructed and will not benefit from surgery, while patients with Qmax < 10 mllsec may be obstructed.g*10.16 To evaluate the clinical usefulness of spontaneous uroflowmetry in prostatism, we addressed the following questions: (1) How do maximum flow rates correlate with other variables believed to describe obstruction? (2) What is the predictive value of maximum flow rate,
/ VOLUME XXIV, NUMBER 4
403
i.e., will patients with high flow rates do worse after surgery than patients with low flow rates? Material and Methods All patients evaluated presented with prostatism and were selected for surgery on the basis of nonurodynamic data only. The evaluation was comprised of physical examination, detailed symptom analysis, excretory urography, post-void residual urine determination, routine blood chemistry, urinalysis, and urine culture. Under symptom analysis, each symptom was graded on a scale from 0 to 4. The total obstructive symptom score was based on the quality of the urinary stream, abdominal straining during voiding, hesitancy, intermittence, sensation of complete bladder emptying, and terminal dribbling. The maximum obtainable score was 18 points. Likewise, the irritative symptom score was derived from the symptoms, urge, nocturia, and frequency; the maximum obtainable was 9 points. All other investigations, including cystoscopic findings and residual urine volume, were scored by a graded number system. The decision to proceed with transurethral resection of the prostate (TURP) was based on total clinical score. Patients less than fifty years of age, with urinary retention, carcinoma of the prostate, urethral stricture, previous TURP, extensive pelvic surgery, or serious psychiatric or neurologic diseases were excluded. Patients with urinary tract infection were excluded temporarily. All patients underwent extensive urodynamic investigation. Using the DISA uroflowmeter, one or more spontaneous uroflowmetry was obtained in each case, followed by residual urine determination. Medium-fill water cystometry was performed with the patient standing, using 0.9 per cent saline at 37” C with a fill rate of 80 ml/min through a 14-F Foley catheter. Intravesical pressure was recorded using an 8.3-F transurethral pigtail catheter while the intraabdominal pressure was recorded by means of an 18-F esophageal catheter inserted per rectum. l7 After cystometry the filling catheter was removed, and the pressure flow study was performed. The graphs, including a subtracted detrusor pressure graph, were recorded on a DISA 8-channel strip chart recorder. Terminology used is in accordance with the International Continence Society proposals,ls except for maximum bladder capacity and the maximum straining pressure.
404
max ave maximum bladder capacity
pves, Qmax pves, max pves, open pdet, Qmax pdet, max pabd, max
R min
maximum flow rate I average flow = the greatest bladder volume (voided volume + residual urine) obtained either at spontaneous uroflowmetry or at pressure flow study = intravesical pressure at maximum flow = maximum intravesical pressure = intravesical pressure at initiation of flow = detrusor pressure at maximum flow = maximum detrusor pressure = maximal intra-abdominal pressure-peak above pressure-baseline, either in cystometrogram or in pressure-flow study = minimum urethral resistance (pves, Qmax/Qmax2)
To determine whether or not differences in Qmax reflected differences in corresponding bladder volume, corrections were made using the formula: corrected Qmax = Qmax/ Jbladder volume, as described previously. After TURP the weight of resected tissue was recorded, and the tissue was examined histologically. Three and twelve months postoperatively the patients were reevaluated using both urodynamic and symptomatologic studies. In addition, all patients were asked to give their subjective evaluation of the result of surgery, graded on a scale of 1 to 5 (from poor to good). All results were placed in a Data General Eclipse computer with Wisar data base and statistically treated by means of correlation analysis, Kruskal-Wallis test for analysis of variance (one-way), Wilcoxon’s test for paired differences, chi-square test with Yates correction, and Fisher’s exact test. Results To date 53 patients have undergone preoperative evaluation while 38 and 22 patients have been reevaluated three and twelve months postoperatively, respectively. Six patients were not reevaluated as scheduled. Urethral stricture developed in 2 patients, 3 were lost for follow-up, and 1 patient died. In a correlation analysis of Qmax and Qave versus symptom scores, cystoscopic and urodynamic
UROLOGY
/ OCTOBER
1984
/ VOLUME
XXIV, NUMBER 4
data revealed a weak correlation with the symptom scores and various urodynamic pressure parameters, while there was no correlation with bladder neck to verumontanum distance and resected weight (Table I). There appeared to be a better correlation with Qmax than Q ave. The 53 patients who underwent preoperative evaluation were divided into the following groups according to the results at preoperative spontaneous uroflowmetry: Group I had Qmax 2 15.0 mllsec, Group II had Qmax in the range of 10.0 to 14.9 mllsec, and Group III had Qmax < 10.0 mllsec. The distribution of patients into Groups I to III is shown in Table II. All preoperative data from the three groups were compared and, apart from differences in Qmax, significant differences were also found in voided volume, bladder volume, and maximal bladder capacity. All volumes were greatest in Group I (Table III Further analysis revealed that the Qmaxi b bladder volume ratio also differed significantly between the groups; that is, even if the patients in the three groups had had the same bladder volume, there still would have been significant differences in Qmax at spontaneous uroflowmetry. No differences between groups were found in symptom scores, bladder neck to verumontanum distance, resected weight, or in the various pressure variables from the pressure flow study. As outlined in Tables IV and V, the three groups did not differ either three or twelve months postoperatively except for the pves, open three months postoperatively. No significant differences were demonstrated between the grou s regardin1g Qmax and the ratio of Qmax,dladd er vo ume postoperatively. Concerning uninhibited detrusor contractions (UDC) no differences were shown between the groups. The overall incidence of UDC was 56.7 per cent preoperatively, 47.1 per cent three months postoperatively, and 29.4 per cent twelve months postoperatively. Although more patients in Group III tended to have persistent
Number of patients evaluated pre- and postoperatively in the different groups
TABLE II.
Group I II III
UROLOGY
’ OCTOBER 1984 / VOLUME XXIV, NUMBER 4
Preoperative 13 14 26
Postoperative 3 Months 12 Months 9 10 19
6 6 10
405
were rather uniform (Table VI). All groups improved in symptom scores and in R min as measured three months postoperatively, while there generally was no change in the pressure variables. Only Group III had an improved
UDC three months postoperatively compared with the other groups, this difference was insignificant. When the postoperative outcome was considered, the results obtained in the three groups TABLE III.
Group I Median Range II Median Range III Median Range Statistics
Comparison of preoperative symptom scores, cystoscopic findings, and various urodynamic data in patients with different Qmax-values at spontaneous urojlometry Resected Weight (Gm)
Uroflowmetry Voided Qmax (ml) Vol. (ml)
Total
SSI
Obstructive
BIVD (cm)
15 11-22
4 3-7
11 6-16
2.5 1.5-4.0
23.5 10-30
65 55-75
17.4 15.4-37.5
359 162-622
434 162-665
16.5 9-20
5 l-9
11 5-15
2.5 1.5-4.0
20 9-50
64.5 54-81
11.2 10.0-14.1
234 102-546
320.5 133-1400
16.5 9-24
5 l-9
12 2-16
3.0 1.0-4.2
20 5-42
65 55-88
8.0 4.4-9.9
156.5 54-334
239 86-127
p < 0.9
p < 0.75
p < 0.75
p < 0.75
p < 0.95
p < 0.9
p < 0.001
p < 0.001
p < 0.005
Age W)
Bladder Vol. (ml)
Comparison of various symptomatologic and urodynamic data three months postoperatively; classification of groups based on preoperative Qmax-values
TABLE IV.
MBC Group I Median Range II Median Range III Median Range Statistics
Uroflowmetry Bladder Qmax Vol. (ml) (ml sec~i)
Total
SSI
Obstructive
(ml)
Voided Vol. (ml)
6 o-14
3 o-7
2 o-11
361.5 157-815
173 69-347
171 69-470
18.9 5.2-38.8
9.9 2.8-20.8
2 o-13
1 o-7
0.5 O-8
415 101-955
357 77-595
367 112-610
19.3 5.5-24.2
10.9 3.1-12.7
3 o-11
2 o-7
2 o-7
373 133-649
171.5 27-369
180 107-409
14.1 3.2-35.5
7.0 2.0-16.0
p < 0.50
p < 0.75
p < 0.50
p < 0.90
p < 0.50
p < 0.25
p < 0.25
p < 0.50
Comparison of various symptomatologic and urodynamic postoperatively; classijication of groups based on preoperative
TABLE V.
Group I Median Range II Median Range III Median Range Statistics
406
Voided Vol. (ml)
Qave (ml see-‘)
data twelve months Qmax-values
Uroflowmetry Bladder Qmax Vol. (ml) (ml set-r)
Total
SSI
Obstructive
MBC (ml)
6 o-14
2.5 o-5
4 O-10
511 139-779
222.5 43-633
232 48-683
23.0 5.1-44.3
10.8 2.5-27. I
6.5 o-11
1 o-7
3 O-10
830 658-897
179 54-638
233 64-798
13.1 6.1-24.4
7.8 3.3-14.0
2.5 o-12
2 o-5
1 o-7
428 224-706
225 84-318
232.5 142-463
15.0 7.8-30.2
8.5 2.0-15.5
p < 0.50
p < 0.75
p < 0.50
p < 0.10
p < 0.95
p < 0.99
p < 0.50
p < 0.90
UROLOGY
i
OCTOBER 1984 i
Qave (ml sect’)
VOLUME XXIV, NUMBER 4
Qmax postoperatively, while all groups improved their Qmax when correction for differences in bladder volume was made, using the ratio of Qmaxldbladder volume. Most differences between preoperative measurements
and those obtained twelve months postoperatively were insignificant. Regarding the patients’ subjective evaluation of surgery three months postoperatively, those with preoperative Qmax < 10.0 ml/set (Group III) reported
TABLE III. ~
Continued
Uroflowmetry
;k
Pressure-Flow Study
&$%% rnW set _ ’
MBC
(see)
(ml)
G:x (cm HzO)
40 22-90
0.84 0.71-1.72
476 215-665
80 60-130
97.5 65-180
45 o-75
43 19-106
0.65 0.37-0.87
362.5 133-1400
100 60-135
100 60-190
41 11-127
0.52 0.23-0.91
280.5 95-530
90 40-200 p < 0.50
p < 0.95 KEY:
p <
p < 0.01
0.001
SSI = symptom
scores irritative;
:z 62; “,d:: (cm HSO) (cm HSO) (cm H,O)
:z (cm H,O)
“t$:’ (cm HzO)
52.5 15-80
87.5 50-130
25 O-110
0.60 0.17-4.25
57.5 35-95
61.5 35-100
95 50-150
35 O-90
1.31 0.30-7.62
100 56-240
55 5-175
65 15-230
90 25-215
25 O-90
1.03 0.27-20.80
p < 0.95
p < 0.25
p < 0.50
p < 0.90
p < 0.75
p < 0.25
BlVD = bladder neck/verumontanumdistance; MBC = maximal bladder capacity. TABLE IV.
-
Continued
Uroflowmetry __ k:
(,R,$ ml2 secmz)
Pressure-Flow Study
ti~;~~vol.
~:x
;;;
pdet,
pdet,
pves,
pabd,
c,R,ming,
(set)
(ml0 5 set-l)
(cm HZO)
(cm HzO)
22 14-47
1.53 0.63-1.89
87.5 70-130
85 75-130
35 25-60
45 25-60
85 75-100
47.5 25-70
0.23 0.10-0.42
38 13-261
1.17 0.36-1.51
60 25-l 10
75 35-160
40 20-65
45 25-70
45 25-185
55 25-145
0.22 0.10-0.72
18 11-51
1.15 0.64-2.43
75 50-135
85 50-145
35 10-75
45 20-110
70 35-110
40 20-90
0.29 0.07-1.78
p < 0.75
p < 0.95
p < 0.99
p < 0.05
p < 0.90
p < 0.75
p < 0.25 KEY:
p < 0.50
SSI = symptom
p < 0.25
scores irritative;
MBC
(cz?&)
(cnY;O)
ml2 secm2)
Continued
Uroflowmetry ;2
(cz’;O)
= maximal bladder capacity
TABLE V. -
(cz;O)
Pressure-Flow Study
&~(h=&,*.
g;x
;v
;?>x
p,“;‘;
“0;;
P;;>
(&rn&
(see)
(ml0 5 see-I)
(cm HzO)
(cm H*O)
(cm H*O)
(cm H,O)
(cm HzO)
(cm H,O)
21.5 15-49
1.57 0.74-1.82
62.5 40-90
85 40-110
35 30-50
45 40-50
72.5 30-95
25 25-40
0.14 0.03-0.32
16.5 13-173
0.99 0.32-1.35
85 35-105
165 50-110
40 O-65
40 5-85
75 50-80
60 45-95
0.34 0.06-1.64
22 14-42
0.90 0.52-1.40
82.5 35-130
95 35-145
27.5 lo-60
32.5 lo-60
75 35-145
40 20-105
0.25 0.11-3.85
p < 0.25
p < 0.75
p < 0.90
p < 0.90
p < 0.50
p < 0.90
p < 0.25
p < 0.50
p < 0.75 KEY:
SSI = symptom scores irritative;
UROLOGY
/ OCTOBER
1984
MBC
ml2 secm2)
= maximal bladder capacity
/ VOLUME XXIV, NUMBER 4
407
TARLE VI.
Preoperative data compared with data obtained three and twelve months postoperatively in same group
Group I 3M 12M Total symptom score Irritative score Obstructive score Max. bladder capacity pves, Qmax pves, max pdet, Qmax pves, open pabd, max R min Bladder vol. Qmax Voided vol. Qmaxim
Q ave
Flow time KEY: M = months;
S S S
S S S
NS NS NS NS NS NS
NS
S
NS NS NS S NS NS NS NS NS S
S NS S S NS NS (p
Comment Although uroflowmetry has been considered practical and useful in screening disorders of the lower urinary tract in males, no critical evaluation has documented its relevance in the preoperative assessment of patients with prostatism. In this investigation patients with prostatism were selected for surgery by nonurodynamic data; the urodynamic diagnosis was not available to the urologist who selected the patients. This study design allowed a thorough evaluation of the applicability of spontaneous uroflowmetry in patients presenting with the symptom complex of prostatism, since patients with moderate and severe symptoms and with both high and low flow underwent surgery.
NS NS
NS NS
S
NS
NS
S
NS
S S S
NS NS
NS
NS
S S
S S S
NS
NS
S NS
NS
NS NS NS NS NS
S
< 0.05):
a significantly better result than patients with higher preoperative Qmax values. This difference was statistically insignificant twelve months postoperatively (Table VII).
NS
NS NS NS S
S S
NS NS NS
NS NS NS
S
12M
S S
S NS
S
3M S
S S
NS NS NS NS NS NS
S
Group III
12M
S
NS
S
S = significant
Group II 3M
S
S
NS = nonsignificant.
In contrast to both Abrams’O and Andersen, Nordling, and Walterr we found a weak but significant correlation between Qmax and symptom scores, which supports the data of Shoukry et ~1.~ The same weak correlation was found when intravesical pressure, detrusor pressure, and minimum urethral resistance were considered, indicating that Qmax might be as useful as these variables in the evaluation of bladder outlet obstruction. Although uroflowmetry was able to define groups of patients with significant differences in volume-corrected flows preoperatively, this classification did not identify groups of patients who differed significantly after surgery. Considering each group separately, all groups showed significant improvement in symptom scores both three and twelve months postoperatively. To our surprise even the high flow group (Qmax 1 15 ml/set) benefited significantly from surgery. This finding is in contrast to the observations of Abrams,‘O who identified a
TABLE VII. Subjective evaluation of outcome of surgery three and twelve months postoperatively, respectively, in patients with preoperative Qmax 2 10.0 ml/set and < 10.0 ml/see Qmax Postoperative 3 Months 12 Months 1 10.0 mlisec < 10.0 ml/see 2 10.0 mlisec < 10.0 mlisec Improved Not Improved Statistics
408
73.7% 26.3%
100.0% 0
66.7% 33.3%
p = 0.02
90.0 % 10.0% p = 0.19
UROLOGY
i
OCTOBER 1984
/
VOLUME XXIV. NUMBER 4
group with high preoperative flow rates and a lower success rate following prostatectomy. Regarding Qmax only Group III improved after surgery, while all groups improved their corrected Qmax when measured three months postoperatively. However, this improvement was insignificant in both Groups I and II one year after surgery, perhaps because of the relatively small number of patients investigated to date. While no objective differences were revealed postoperatively between the groups, patients with preoperative Qmax < 10 ml/set had a significantly better subjective outcome of surgery as determined three months postoperatively, although the difference was insignificant one year after surgery. The reason for this difference at three months after surgery is unclear, but factors other than the voiding process itself, e.g., impairment of potency or orgasm,20 might have influenced this evaluation. In this prospective study, no role could be identified for spontaneous uroflowmetry as a screening procedure in patients with wellestablished prostatism. Identification of patients destined to have a less favorable outcome of surgery was not possible. However, measurement of flow might be justified in patients with vague symptoms of prostatism, in patients with azotemia and/or hydroureteronephrosis in the absence of prostatism, and in postoperative follow-up. Madison, Wisconsin 53705 (DR. BRUSKEWITZ) References 1. Rehfisch M: Uber den Mechanismus lusses und der Harnentleerung, Virchows 111 (1897).
UROLOGY
i
OCTOBER
1984
des HarnblasenverschArch [Pathol Anat] 150:
! VOLUME
XXIV. NUMBER
2. Gronvall H: Blastomningens mekanism, Lakartidningen 22: 577 (1925). 3. Drake WM Jr: The uroflowmeter: an aid to the study of the lower urinary tract, J Urol 59: 650 (1948). 4. Von Garrelts B: Analysis of micturition: a new method of recording the voiding of the bladder, Acta Chir Stand 112: 326 (1956). 5. Kaufman JJ: A new recording uroflowmeter: a simple automatic device for measuring voiding velocitv.I _ I Urol 78: 97 (1957). 6. Drach GW, Layton TN, and Binard WJ: Male peak urinary flow rate: relationships to volume voided and age, ibid 122: 210 (1979). 7. Layton TN, and Drach GW: Selectivity of peak versus average male urinary flow rates, ibid 125: 839 (1981). 8. Shoukry I, Susset JG, Elhilali MM, and Dutartre D: Role of uroflowmetr) in the assessment of lower urinary tract obstruction in adult males. Br I Urol 47: 559 (1975). 9. Anikwe RM:* Urinary flow ‘rate’in benign prostatic hypertrophy, Int Surg 61: 109 (1976). 10. Abrams PH: Prostatism and prostatectomy: the value of urine flow rate measurement in the preoperative assessment for operation, J Urol 117: 70 (1977). 11. Von Garrelts B: Micturition in the normal male, Acta Chir Stand 114: 197 (1957). 12. Siroky MB, Olsson CA, and Krane RJ: The flow rate nomogram: I. Development, J Urol 122: 665 (1979). 13. Ryall RL, and Marshall VR: Normal peak urinary flow rates obtained from small voided volumes can provide a reliable assessment of bladder function, ibid 127: 484 (1982). 14. Scott FB, Cardus D, Quesada EM, and Riles T: Uroflowmetry before and after prostatectomy, South Med J 60: 948 (1967). 15. Pearson RM, and Noe HN: Why urodynamic studies are important in urologic problems of the elderly, Geriatrics 34: 43 (1979). 16. Von Garrelts B: The urinary flow rate and the voiding pressure, in Hinman F Jr (Ed): Hydrodynamics of Micturition, Springfield, Illinois, Charles C Thomas, 1971, p 169. 17. Bruskewitz R, and Raz S: Use of esophageal catheter to record rectal pressures in urodynamics, Urology 15: 508 (1980). 18. Bates P, et al: The standardization of terminology of lower urinary tract function, J Urol 121: 551 (1979). 19. Andersen JT, Nordling J, and Walter S: Prostatism. I. The correlation between symptoms, cystometric and urodynamic findings, Stand J Urol Nephrol 13: 229 (1979). 20. Jensen K.M.-E., Sonneland P, and Madsen PO: Seminal vesicletissue in resectate of transurethral resection of the prostate, Urology 22: 20 (1983).
4
409
JENSEN,
M.D.
C. BRUSKEWITZ,
IVERSEN,
PAUL 0. MADSEN,
IN PROSTATISM*
M.D.
M.D. M.D.
From the Section of Urology, William S. Middleton Memorial Veterans Administration Hospital, and Department of Urology, University of Wisconsin, Madison, Wisconsin
ABSTRACTUroflowmetry is a valuable urodynamic screening procedure in selecting patients with prostatism for surgery. A prospective study was undertaken in which patients were selected for transurethral resection of the prostate by means of nonurodynamic data only. All patients underwent extensive urodynamic testing. Fifty-three patients were studied preoperatively, while 38 were examined at three months and 22 at twelve months postoperatively. A weak correlation was noted between maximum flow rate and symptom scores, pressure variables, and minimum urethral resistance. However, classification of patients by groups of high, medium, and low maximum flow rates did not identify groups of patients with less favorable outcome of surgery, i.e., patients with higher flow rates did as well as those with lower flow rates. A clear role for spontaneous uroflowmetry could not be identified in the preoperative evaluation of patients with prostatism.
Measurement of the voiding stream has had a prominent place in evaluating disorders of the lower urinary tract. The first uroflowmeters were developed in 1897 by Rehfisch’ and in 1925 by Grijnval. 2 After the description of Drake’s apparatus in 194S3 von Garrelts4 and Kaufman5 developed more sophisticated electronic devices in 1956 and 1957, and uroflowmeter development accelerated. The most useful flow variable in prostatism has been the maximum flow rate (Qmax), which decreases with advancing patient age and increases with increasing vo1ume.6-10 The volumeflow relationship has been mathematically described as a straight line and as hyperbolic and parabolic curves. When Qmax is plotted against the square root of the volume, the graph approximates a straight line,“-I3 implying that the ratio Qmax/dvolume is constant, and consequently that a minimal acceptable volume of *Research supported in part by Veterans Administration
UROLOGY
/ OCTOBER
1984
150 ml is not crucial. This fact is especially important in patients with uninhibited detrusor contractions resulting in small functional bladder capacity. The volume considered should be bladder volume rather than voided volume because the latter, in the presence of residual urine, will lead to overestimation of voiding ability. l l In patients with prostatism uroflowmetry has been found to be valuable as a simple, noninvasive procedure in both pre- and postoperative evaluation.10.14,‘5 For prostatism current dogma holds that patients with Qmax > 15 ml/set are nonobstructed and will not benefit from surgery, while patients with Qmax < 10 mllsec may be obstructed.g*10.16 To evaluate the clinical usefulness of spontaneous uroflowmetry in prostatism, we addressed the following questions: (1) How do maximum flow rates correlate with other variables believed to describe obstruction? (2) What is the predictive value of maximum flow rate,
/ VOLUME XXIV, NUMBER 4
403
i.e., will patients with high flow rates do worse after surgery than patients with low flow rates? Material and Methods All patients evaluated presented with prostatism and were selected for surgery on the basis of nonurodynamic data only. The evaluation was comprised of physical examination, detailed symptom analysis, excretory urography, post-void residual urine determination, routine blood chemistry, urinalysis, and urine culture. Under symptom analysis, each symptom was graded on a scale from 0 to 4. The total obstructive symptom score was based on the quality of the urinary stream, abdominal straining during voiding, hesitancy, intermittence, sensation of complete bladder emptying, and terminal dribbling. The maximum obtainable score was 18 points. Likewise, the irritative symptom score was derived from the symptoms, urge, nocturia, and frequency; the maximum obtainable was 9 points. All other investigations, including cystoscopic findings and residual urine volume, were scored by a graded number system. The decision to proceed with transurethral resection of the prostate (TURP) was based on total clinical score. Patients less than fifty years of age, with urinary retention, carcinoma of the prostate, urethral stricture, previous TURP, extensive pelvic surgery, or serious psychiatric or neurologic diseases were excluded. Patients with urinary tract infection were excluded temporarily. All patients underwent extensive urodynamic investigation. Using the DISA uroflowmeter, one or more spontaneous uroflowmetry was obtained in each case, followed by residual urine determination. Medium-fill water cystometry was performed with the patient standing, using 0.9 per cent saline at 37” C with a fill rate of 80 ml/min through a 14-F Foley catheter. Intravesical pressure was recorded using an 8.3-F transurethral pigtail catheter while the intraabdominal pressure was recorded by means of an 18-F esophageal catheter inserted per rectum. l7 After cystometry the filling catheter was removed, and the pressure flow study was performed. The graphs, including a subtracted detrusor pressure graph, were recorded on a DISA 8-channel strip chart recorder. Terminology used is in accordance with the International Continence Society proposals,ls except for maximum bladder capacity and the maximum straining pressure.
404
max ave maximum bladder capacity
pves, Qmax pves, max pves, open pdet, Qmax pdet, max pabd, max
R min
maximum flow rate I average flow = the greatest bladder volume (voided volume + residual urine) obtained either at spontaneous uroflowmetry or at pressure flow study = intravesical pressure at maximum flow = maximum intravesical pressure = intravesical pressure at initiation of flow = detrusor pressure at maximum flow = maximum detrusor pressure = maximal intra-abdominal pressure-peak above pressure-baseline, either in cystometrogram or in pressure-flow study = minimum urethral resistance (pves, Qmax/Qmax2)
To determine whether or not differences in Qmax reflected differences in corresponding bladder volume, corrections were made using the formula: corrected Qmax = Qmax/ Jbladder volume, as described previously. After TURP the weight of resected tissue was recorded, and the tissue was examined histologically. Three and twelve months postoperatively the patients were reevaluated using both urodynamic and symptomatologic studies. In addition, all patients were asked to give their subjective evaluation of the result of surgery, graded on a scale of 1 to 5 (from poor to good). All results were placed in a Data General Eclipse computer with Wisar data base and statistically treated by means of correlation analysis, Kruskal-Wallis test for analysis of variance (one-way), Wilcoxon’s test for paired differences, chi-square test with Yates correction, and Fisher’s exact test. Results To date 53 patients have undergone preoperative evaluation while 38 and 22 patients have been reevaluated three and twelve months postoperatively, respectively. Six patients were not reevaluated as scheduled. Urethral stricture developed in 2 patients, 3 were lost for follow-up, and 1 patient died. In a correlation analysis of Qmax and Qave versus symptom scores, cystoscopic and urodynamic
UROLOGY
/ OCTOBER
1984
/ VOLUME
XXIV, NUMBER 4
data revealed a weak correlation with the symptom scores and various urodynamic pressure parameters, while there was no correlation with bladder neck to verumontanum distance and resected weight (Table I). There appeared to be a better correlation with Qmax than Q ave. The 53 patients who underwent preoperative evaluation were divided into the following groups according to the results at preoperative spontaneous uroflowmetry: Group I had Qmax 2 15.0 mllsec, Group II had Qmax in the range of 10.0 to 14.9 mllsec, and Group III had Qmax < 10.0 mllsec. The distribution of patients into Groups I to III is shown in Table II. All preoperative data from the three groups were compared and, apart from differences in Qmax, significant differences were also found in voided volume, bladder volume, and maximal bladder capacity. All volumes were greatest in Group I (Table III Further analysis revealed that the Qmaxi b bladder volume ratio also differed significantly between the groups; that is, even if the patients in the three groups had had the same bladder volume, there still would have been significant differences in Qmax at spontaneous uroflowmetry. No differences between groups were found in symptom scores, bladder neck to verumontanum distance, resected weight, or in the various pressure variables from the pressure flow study. As outlined in Tables IV and V, the three groups did not differ either three or twelve months postoperatively except for the pves, open three months postoperatively. No significant differences were demonstrated between the grou s regardin1g Qmax and the ratio of Qmax,dladd er vo ume postoperatively. Concerning uninhibited detrusor contractions (UDC) no differences were shown between the groups. The overall incidence of UDC was 56.7 per cent preoperatively, 47.1 per cent three months postoperatively, and 29.4 per cent twelve months postoperatively. Although more patients in Group III tended to have persistent
Number of patients evaluated pre- and postoperatively in the different groups
TABLE II.
Group I II III
UROLOGY
’ OCTOBER 1984 / VOLUME XXIV, NUMBER 4
Preoperative 13 14 26
Postoperative 3 Months 12 Months 9 10 19
6 6 10
405
were rather uniform (Table VI). All groups improved in symptom scores and in R min as measured three months postoperatively, while there generally was no change in the pressure variables. Only Group III had an improved
UDC three months postoperatively compared with the other groups, this difference was insignificant. When the postoperative outcome was considered, the results obtained in the three groups TABLE III.
Group I Median Range II Median Range III Median Range Statistics
Comparison of preoperative symptom scores, cystoscopic findings, and various urodynamic data in patients with different Qmax-values at spontaneous urojlometry Resected Weight (Gm)
Uroflowmetry Voided Qmax (ml) Vol. (ml)
Total
SSI
Obstructive
BIVD (cm)
15 11-22
4 3-7
11 6-16
2.5 1.5-4.0
23.5 10-30
65 55-75
17.4 15.4-37.5
359 162-622
434 162-665
16.5 9-20
5 l-9
11 5-15
2.5 1.5-4.0
20 9-50
64.5 54-81
11.2 10.0-14.1
234 102-546
320.5 133-1400
16.5 9-24
5 l-9
12 2-16
3.0 1.0-4.2
20 5-42
65 55-88
8.0 4.4-9.9
156.5 54-334
239 86-127
p < 0.9
p < 0.75
p < 0.75
p < 0.75
p < 0.95
p < 0.9
p < 0.001
p < 0.001
p < 0.005
Age W)
Bladder Vol. (ml)
Comparison of various symptomatologic and urodynamic data three months postoperatively; classification of groups based on preoperative Qmax-values
TABLE IV.
MBC Group I Median Range II Median Range III Median Range Statistics
Uroflowmetry Bladder Qmax Vol. (ml) (ml sec~i)
Total
SSI
Obstructive
(ml)
Voided Vol. (ml)
6 o-14
3 o-7
2 o-11
361.5 157-815
173 69-347
171 69-470
18.9 5.2-38.8
9.9 2.8-20.8
2 o-13
1 o-7
0.5 O-8
415 101-955
357 77-595
367 112-610
19.3 5.5-24.2
10.9 3.1-12.7
3 o-11
2 o-7
2 o-7
373 133-649
171.5 27-369
180 107-409
14.1 3.2-35.5
7.0 2.0-16.0
p < 0.50
p < 0.75
p < 0.50
p < 0.90
p < 0.50
p < 0.25
p < 0.25
p < 0.50
Comparison of various symptomatologic and urodynamic postoperatively; classijication of groups based on preoperative
TABLE V.
Group I Median Range II Median Range III Median Range Statistics
406
Voided Vol. (ml)
Qave (ml see-‘)
data twelve months Qmax-values
Uroflowmetry Bladder Qmax Vol. (ml) (ml set-r)
Total
SSI
Obstructive
MBC (ml)
6 o-14
2.5 o-5
4 O-10
511 139-779
222.5 43-633
232 48-683
23.0 5.1-44.3
10.8 2.5-27. I
6.5 o-11
1 o-7
3 O-10
830 658-897
179 54-638
233 64-798
13.1 6.1-24.4
7.8 3.3-14.0
2.5 o-12
2 o-5
1 o-7
428 224-706
225 84-318
232.5 142-463
15.0 7.8-30.2
8.5 2.0-15.5
p < 0.50
p < 0.75
p < 0.50
p < 0.10
p < 0.95
p < 0.99
p < 0.50
p < 0.90
UROLOGY
i
OCTOBER 1984 i
Qave (ml sect’)
VOLUME XXIV, NUMBER 4
Qmax postoperatively, while all groups improved their Qmax when correction for differences in bladder volume was made, using the ratio of Qmaxldbladder volume. Most differences between preoperative measurements
and those obtained twelve months postoperatively were insignificant. Regarding the patients’ subjective evaluation of surgery three months postoperatively, those with preoperative Qmax < 10.0 ml/set (Group III) reported
TABLE III. ~
Continued
Uroflowmetry
;k
Pressure-Flow Study
&$%% rnW set _ ’
MBC
(see)
(ml)
G:x (cm HzO)
40 22-90
0.84 0.71-1.72
476 215-665
80 60-130
97.5 65-180
45 o-75
43 19-106
0.65 0.37-0.87
362.5 133-1400
100 60-135
100 60-190
41 11-127
0.52 0.23-0.91
280.5 95-530
90 40-200 p < 0.50
p < 0.95 KEY:
p <
p < 0.01
0.001
SSI = symptom
scores irritative;
:z 62; “,d:: (cm HSO) (cm HSO) (cm H,O)
:z (cm H,O)
“t$:’ (cm HzO)
52.5 15-80
87.5 50-130
25 O-110
0.60 0.17-4.25
57.5 35-95
61.5 35-100
95 50-150
35 O-90
1.31 0.30-7.62
100 56-240
55 5-175
65 15-230
90 25-215
25 O-90
1.03 0.27-20.80
p < 0.95
p < 0.25
p < 0.50
p < 0.90
p < 0.75
p < 0.25
BlVD = bladder neck/verumontanumdistance; MBC = maximal bladder capacity. TABLE IV.
-
Continued
Uroflowmetry __ k:
(,R,$ ml2 secmz)
Pressure-Flow Study
ti~;~~vol.
~:x
;;;
pdet,
pdet,
pves,
pabd,
c,R,ming,
(set)
(ml0 5 set-l)
(cm HZO)
(cm HzO)
22 14-47
1.53 0.63-1.89
87.5 70-130
85 75-130
35 25-60
45 25-60
85 75-100
47.5 25-70
0.23 0.10-0.42
38 13-261
1.17 0.36-1.51
60 25-l 10
75 35-160
40 20-65
45 25-70
45 25-185
55 25-145
0.22 0.10-0.72
18 11-51
1.15 0.64-2.43
75 50-135
85 50-145
35 10-75
45 20-110
70 35-110
40 20-90
0.29 0.07-1.78
p < 0.75
p < 0.95
p < 0.99
p < 0.05
p < 0.90
p < 0.75
p < 0.25 KEY:
p < 0.50
SSI = symptom
p < 0.25
scores irritative;
MBC
(cz?&)
(cnY;O)
ml2 secm2)
Continued
Uroflowmetry ;2
(cz’;O)
= maximal bladder capacity
TABLE V. -
(cz;O)
Pressure-Flow Study
&~(h=&,*.
g;x
;v
;?>x
p,“;‘;
“0;;
P;;>
(&rn&
(see)
(ml0 5 see-I)
(cm HzO)
(cm H*O)
(cm H*O)
(cm H,O)
(cm HzO)
(cm H,O)
21.5 15-49
1.57 0.74-1.82
62.5 40-90
85 40-110
35 30-50
45 40-50
72.5 30-95
25 25-40
0.14 0.03-0.32
16.5 13-173
0.99 0.32-1.35
85 35-105
165 50-110
40 O-65
40 5-85
75 50-80
60 45-95
0.34 0.06-1.64
22 14-42
0.90 0.52-1.40
82.5 35-130
95 35-145
27.5 lo-60
32.5 lo-60
75 35-145
40 20-105
0.25 0.11-3.85
p < 0.25
p < 0.75
p < 0.90
p < 0.90
p < 0.50
p < 0.90
p < 0.25
p < 0.50
p < 0.75 KEY:
SSI = symptom scores irritative;
UROLOGY
/ OCTOBER
1984
MBC
ml2 secm2)
= maximal bladder capacity
/ VOLUME XXIV, NUMBER 4
407
TARLE VI.
Preoperative data compared with data obtained three and twelve months postoperatively in same group
Group I 3M 12M Total symptom score Irritative score Obstructive score Max. bladder capacity pves, Qmax pves, max pdet, Qmax pves, open pabd, max R min Bladder vol. Qmax Voided vol. Qmaxim
Q ave
Flow time KEY: M = months;
S S S
S S S
NS NS NS NS NS NS
NS
S
NS NS NS S NS NS NS NS NS S
S NS S S NS NS (p
Comment Although uroflowmetry has been considered practical and useful in screening disorders of the lower urinary tract in males, no critical evaluation has documented its relevance in the preoperative assessment of patients with prostatism. In this investigation patients with prostatism were selected for surgery by nonurodynamic data; the urodynamic diagnosis was not available to the urologist who selected the patients. This study design allowed a thorough evaluation of the applicability of spontaneous uroflowmetry in patients presenting with the symptom complex of prostatism, since patients with moderate and severe symptoms and with both high and low flow underwent surgery.
NS NS
NS NS
S
NS
NS
S
NS
S S S
NS NS
NS
NS
S S
S S S
NS
NS
S NS
NS
NS NS NS NS NS
S
< 0.05):
a significantly better result than patients with higher preoperative Qmax values. This difference was statistically insignificant twelve months postoperatively (Table VII).
NS
NS NS NS S
S S
NS NS NS
NS NS NS
S
12M
S S
S NS
S
3M S
S S
NS NS NS NS NS NS
S
Group III
12M
S
NS
S
S = significant
Group II 3M
S
S
NS = nonsignificant.
In contrast to both Abrams’O and Andersen, Nordling, and Walterr we found a weak but significant correlation between Qmax and symptom scores, which supports the data of Shoukry et ~1.~ The same weak correlation was found when intravesical pressure, detrusor pressure, and minimum urethral resistance were considered, indicating that Qmax might be as useful as these variables in the evaluation of bladder outlet obstruction. Although uroflowmetry was able to define groups of patients with significant differences in volume-corrected flows preoperatively, this classification did not identify groups of patients who differed significantly after surgery. Considering each group separately, all groups showed significant improvement in symptom scores both three and twelve months postoperatively. To our surprise even the high flow group (Qmax 1 15 ml/set) benefited significantly from surgery. This finding is in contrast to the observations of Abrams,‘O who identified a
TABLE VII. Subjective evaluation of outcome of surgery three and twelve months postoperatively, respectively, in patients with preoperative Qmax 2 10.0 ml/set and < 10.0 ml/see Qmax Postoperative 3 Months 12 Months 1 10.0 mlisec < 10.0 ml/see 2 10.0 mlisec < 10.0 mlisec Improved Not Improved Statistics
408
73.7% 26.3%
100.0% 0
66.7% 33.3%
p = 0.02
90.0 % 10.0% p = 0.19
UROLOGY
i
OCTOBER 1984
/
VOLUME XXIV. NUMBER 4
group with high preoperative flow rates and a lower success rate following prostatectomy. Regarding Qmax only Group III improved after surgery, while all groups improved their corrected Qmax when measured three months postoperatively. However, this improvement was insignificant in both Groups I and II one year after surgery, perhaps because of the relatively small number of patients investigated to date. While no objective differences were revealed postoperatively between the groups, patients with preoperative Qmax < 10 ml/set had a significantly better subjective outcome of surgery as determined three months postoperatively, although the difference was insignificant one year after surgery. The reason for this difference at three months after surgery is unclear, but factors other than the voiding process itself, e.g., impairment of potency or orgasm,20 might have influenced this evaluation. In this prospective study, no role could be identified for spontaneous uroflowmetry as a screening procedure in patients with wellestablished prostatism. Identification of patients destined to have a less favorable outcome of surgery was not possible. However, measurement of flow might be justified in patients with vague symptoms of prostatism, in patients with azotemia and/or hydroureteronephrosis in the absence of prostatism, and in postoperative follow-up. Madison, Wisconsin 53705 (DR. BRUSKEWITZ) References 1. Rehfisch M: Uber den Mechanismus lusses und der Harnentleerung, Virchows 111 (1897).
UROLOGY
i
OCTOBER
1984
des HarnblasenverschArch [Pathol Anat] 150:
! VOLUME
XXIV. NUMBER
2. Gronvall H: Blastomningens mekanism, Lakartidningen 22: 577 (1925). 3. Drake WM Jr: The uroflowmeter: an aid to the study of the lower urinary tract, J Urol 59: 650 (1948). 4. Von Garrelts B: Analysis of micturition: a new method of recording the voiding of the bladder, Acta Chir Stand 112: 326 (1956). 5. Kaufman JJ: A new recording uroflowmeter: a simple automatic device for measuring voiding velocitv.I _ I Urol 78: 97 (1957). 6. Drach GW, Layton TN, and Binard WJ: Male peak urinary flow rate: relationships to volume voided and age, ibid 122: 210 (1979). 7. Layton TN, and Drach GW: Selectivity of peak versus average male urinary flow rates, ibid 125: 839 (1981). 8. Shoukry I, Susset JG, Elhilali MM, and Dutartre D: Role of uroflowmetr) in the assessment of lower urinary tract obstruction in adult males. Br I Urol 47: 559 (1975). 9. Anikwe RM:* Urinary flow ‘rate’in benign prostatic hypertrophy, Int Surg 61: 109 (1976). 10. Abrams PH: Prostatism and prostatectomy: the value of urine flow rate measurement in the preoperative assessment for operation, J Urol 117: 70 (1977). 11. Von Garrelts B: Micturition in the normal male, Acta Chir Stand 114: 197 (1957). 12. Siroky MB, Olsson CA, and Krane RJ: The flow rate nomogram: I. Development, J Urol 122: 665 (1979). 13. Ryall RL, and Marshall VR: Normal peak urinary flow rates obtained from small voided volumes can provide a reliable assessment of bladder function, ibid 127: 484 (1982). 14. Scott FB, Cardus D, Quesada EM, and Riles T: Uroflowmetry before and after prostatectomy, South Med J 60: 948 (1967). 15. Pearson RM, and Noe HN: Why urodynamic studies are important in urologic problems of the elderly, Geriatrics 34: 43 (1979). 16. Von Garrelts B: The urinary flow rate and the voiding pressure, in Hinman F Jr (Ed): Hydrodynamics of Micturition, Springfield, Illinois, Charles C Thomas, 1971, p 169. 17. Bruskewitz R, and Raz S: Use of esophageal catheter to record rectal pressures in urodynamics, Urology 15: 508 (1980). 18. Bates P, et al: The standardization of terminology of lower urinary tract function, J Urol 121: 551 (1979). 19. Andersen JT, Nordling J, and Walter S: Prostatism. I. The correlation between symptoms, cystometric and urodynamic findings, Stand J Urol Nephrol 13: 229 (1979). 20. Jensen K.M.-E., Sonneland P, and Madsen PO: Seminal vesicletissue in resectate of transurethral resection of the prostate, Urology 22: 20 (1983).
4
409