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Noninvasive Pressure Flow Studies in the Evaluation of Men with Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: A Review of 50,000 Patients

2020; Lippincott Williams & Wilkins; Volume: 204; Issue: 6 Linguagem: Inglês

10.1097/ju.0000000000001195

1527-3792

Steven A. Kaplan, Tobias Köhler, Sankar J. Kausik,

Pelvic floor disorders treatments

You have accessJournal of UrologyAdult Urology1 Dec 2020Noninvasive Pressure Flow Studies in the Evaluation of Men with Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: A Review of 50,000 PatientsThis article is commented on by the following:Editorial CommentEditorial Comment Steven A. Kaplan, Tobias S. Kohler, and Sankar J. Kausik Steven A. KaplanSteven A. Kaplan Mt. Sinai, New York, New York , Tobias S. KohlerTobias S. Kohler Mayo Clinic, Rochester, Minnesota , and Sankar J. KausikSankar J. Kausik Chesapeake Urology, Belair, Maryland View All Author Informationhttps://doi.org/10.1097/JU.0000000000001195AboutAbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Abstract Purpose: The UroCuff® Test is a noninvasive pressure flow study used to manage men with lower urinary tract symptoms. UroCuff Tests were performed on men with lower urinary tract symptoms to evaluate voiding characteristics and quantify changes in urodynamic parameters with age. Materials and Methods: This cross-sectional study included all UroCuff Tests performed at 103 urology practices in the U.S. Tests were de-identified prior to collection and analysis. Inclusion criteria required initial pressure flow study with subsequent tests excluded, voided volume 50 ml or greater, at least 1 cuff inflation and patient age greater than 20 years. Pressure, maximum flow rate, flow rate efficiency (maximum flow rate/Pcuff), voided volume and post-void residual were plotted by age and stratified by Newcastle Noninvasive Nomogram category. Results: A total of 50,680 patients 20 to 100 years old (median age 66.0) met inclusion criteria. Median Pcuff was 144.3 cmH2O and 60.8% of patients were categorized in the obstructed or high pressure/high flow Newcastle Noninvasive Nomogram quadrants. Median maximum flow rate was 10.9 ml per second and 55.8% had maximum flow rate greater than 10 ml per second. Median voided volume and post-void residual were 219.0 and 75.0 ml, respectively. All measures deteriorated with age (p <0.0001). Pcuff reflects the compensated/decompensated bladder function lifecycle. Values initially increased and reached peak pressure at age 62, then decreased by approximately 0.96 cmH2O per year until age 90. Conclusions: This study demonstrates that symptomatic patients enter urological practices at different urodynamic stages of bladder function and outlet obstruction, that Pcuff, maximum flow rate, voided volume, flow rate efficiency and post-void residual deteriorate with age, and that UroCuff is a sensitive evaluation of bladder performance. Abbreviations and Acronyms BPH benign prostatic hyperplasia FRE flow rate efficiency LUTS lower urinary tract symptoms NNN Newcastle Noninvasive Nomogram PFS pressure flow study PVR post-void residual Qmax maximum flow rate VV voided volume Benign prostatic hyperplasia is progressive disease state in which the bladder is challenged with increasing outlet resistance in the prostatic urethra. Over time, as a result of chronic high outlet resistance caused by BPH, bladder function is gradually and eventually impaired. Without intervention, patients with BPH can experience an initial phase of bladder compensation in which bladder pressure is increased during urination, followed by an eventual decompensation phase in which the bladder becomes trabeculated and loses its ability to sustain high contraction levels.1,2 This deterioration of bladder function can ultimately lead to bladder failure and urinary retention which can only be managed with a chronic drainage catheter. Led by the American Urological Association (AUA), urologists are increasingly interested in understanding bladder function and potential bladder outlet obstruction in men with lower urinary tract symptoms attributed to BPH and providing them optimal treatment. The 2018 version of the AUA Guideline on BPH calls for expanded use of pressure flow studies to diagnose certain male patients with LUTS as PFS improves the urologist's understanding of bladder function and bladder outlet obstruction.3 The UroCuff Test is a noninvasive PFS that assesses the relationship of vesical pressure and urine flow using a naturally filled bladder without the need for a urethral catheter. This noninvasive test simultaneously measures vesical pressure and urine flow rate and presents these results on a modified ICS (International Continence Society) nomogram. The UroCuff Test has been shown to be reproducible,4–6 validated,7–9 and highly correlated with catheterized urodynamics studies.9–11 The UroCuff Test is sensitive to changes following BPH treatment and has been shown to be a strong predictor of BPH treatment outcomes.12–14 In 2019 more than 90% of all PFSs performed on male patients with LUTS in the participating sites was performed with the UroCuff Test. The goal of this multisite observational, cross-sectional, retrospective study was to assess the voiding characteristics of men with LUTS as they initially present and to determine whether a deterioration of urodynamic function occurs with patient age. Materials and Methods Study Design This multisite, cross-sectional, retrospective study was categorized as exempt by Sterling IRB per 45 CFR §46.104 and informed consent was not required per 45 CFR §46.116. Registration on ClinicalTrials.gov was not required as this study is not an applicable clinical trial per 42 CFR §11.22. UroCuff Test Protocol The UroCuff Test PFS protocol simulates conditions of a natural void. The patient is instructed to drink fluids to naturally fill the bladder. After the patient reports a strong desire to void, the UroCuff/UroCuff DC Test is performed on the CT3000Plus Complete Urodynamics™ instrument or CT3000Pro Complete Urodynamics™ instrument (SRS Medical, North Billerica, Massachusetts). With the subject standing, a urethral cuff is applied to the patient. Optionally, surface electromyography electrodes are attached to the perineum to detect detrusor-sphincter dyssynergia, and/or surface electromyography electrodes are attached to the abdomen to detect abdominal straining. The patient is positioned over a flowmeter and begins to naturally void. As the void commences the urethral cuff is inflated, and the corresponding changes in urine flow rate and cuff pressure are measured. Data Collection Patient age is recorded and the UroCuff Test protocol performed. Pcuffint (Pcuff), defined as the maximum pressure required to interrupt the void, is calculated along with the maximum urine flow rate and voided volume. Post-void residual is optional and not required to complete the UroCuff Test. Once the test is complete, the instrument plots pressure and flow data on the Newcastle Noninvasive Nomogram, which has the 4 categories of unobstructed, high pressure/high flow, obstructed and low pressure/low flow (fig. 1).15 All patient specific information is stored on the instrument. Figure 1. Example of NNN for obstructed patient tested with UroCuff. Patient specific data for every initial UroCuff Test conducted at each of our centers were retrieved from the instrument (Appendix 1). Protected health information was de-identified before data were extracted and made available for analysis. Selection Criteria Initial UroCuff Tests for all patients were extracted. Only patients 20 years old or older with an initial UroCuff Test that resulted in a successful void were included in the analysis. Successful void was defined as VV 50 ml or greater and at least 1 successful cuff inflation. Statistical Analysis Continuous variables were tested for normality, and median and IQR are reported for summary stats. Pcuff, Qmax, VV, FRE and PVR were stratified by age groups and by obstruction category using the Newcastle Noninvasive Nomogram. Data analysis and graphing were performed with Microsoft® Power BI®. The Kruskal-Wallis test by ranks was used to test NNN and age versus the continuous variables. FRE is defined as the amount of flow per unit of pressure and is reported in ml/cmH2O. Results In total, data for 56,711 male patients tested at 103 locations were extracted from the instruments. Of the 56,711 patients 50,680 met inclusion criteria (89.4%) and were included in the analysis. Of the 50,680 patients 575 (1.1%) did not have a valid patient age entered, and, therefore, age data were available for 50,105 patients. As PVR is an optional field the complete data set was not available. Data were collected for 18,798 of 50,680 (37.1%) patients. Age Distribution Median patient age was 66 years (IQR 58–73) and 31,021 of 50,105 (61.9%) patients were in their 60s or 70s. More than 10%, or 5,123 of 50,105 men, were less than 50 years old (fig. 2). Figure 2. Distribution of patient age in 1-year increments. Overall 575 patients (1.1%) had invalid patient age and were excluded from calculation, so figure represents 50,105 patients. PFS Distribution Median Qmax was 10.9 ml per second (IQR 7.5–15.6) and 28,282 of 50,680 (55.8%) patients had maximum flow rates greater than 10 ml per second (fig. 3). Median Pcuff was 144.3 cmH2O (IQR 109.5–185.0) and 30,826 of 50,680 (60.8%) patients had peak pressures categorized in the obstructed or high pressure/high flow NNN quadrants (table 1). The UroCuff classic protocol applies a maximum cuff pressure of 185 cmH2O to address patient comfort. Overall 12,666 of 50,680 (25.0%) patients reached the maximum applied cuff pressure, indicating Pcuff values of 185 cmH2O or greater. Figure 3. Distribution of Pcuff and Qmax. A, Pcuff results in increments of 5 cmH2O, 38,014/50,680 patients truncated at Pcuff 185 cmH2O or greater. B, Qmax results in increments of 1 ml, 50,566/50,680 patients truncated at Qmax 60 ml per second or greater. Table 1. Distribution of PFS results by NNN diagnostic category No. (%) Unobstructed 12,277 (24.2) High pressure/high flow 16,005 (31.6) Obstructed 14,821 (29.2) Low pressure/low flow 7,577 (15.0) VV and PVR Distribution Median VV was 219.0 ml (IQR 138–337) and 28,226 of 50,680 (55.7%) of patients had a VV of 200 ml or greater (fig. 4). Median PVR was 75 ml (IQR 30–140) and 14,452 of 18,798 (76.9%) patients had a PVR less than 150 ml and 1,275 of 18,798 (6.8%) patients had a PVR of 300 ml or greater. Figure 4. Distribution of VV and PVR. A, histogram of VV for all 50,680 patients plotted in increments of 10 ml. B, histogram of PVR plotted in increments of 10 ml. PVR is available for 18,806 patients. PVR 800 ml or greater is not shown in 67. Relationship of Patient Age to PFS Results Figure 5 depicts age related changes in Pcuff, FRE, Qmax, VV and PVR. Table 2 summarizes each urodynamic measure by decade. All 5 urodynamic measures deteriorated with age (p <0.0001 for all). Figure 5. PFS results by age, moving average over 3 years Table 2. PFS parameters vs age cohort Age Grouping Median (IQR) Pcuff (cmH2O) Qmax (ml/sec) VV (ml) FRE (Qmax/Pcuff) PVR (ml) Younger than than 50 139.3 (106.1–178.3) 14.5 (9.9–20.3) 302.0 (184.0–455.0) 0.110 (0.075–0.157) 48.0 (25.0–102.5) 50–59 148.1 (113.8–187.2) 12.1 (8.3–17.3) 257.5 (162.0–388.0) 0.088 (0.0600.128) 60.0 (28.0–131.0) 60–69 148.6 (113.6–187.0) 10.8 (7.5–15.3) 225.0 (143.0–338.0) 0.078 (0.054– 0.114) 70.0 (31.0–148.0) 70–79 142.3 (108.2–182.3) 9.9 (6.9–14.0) 194.0 (124.0–287.0) 0.074 (0.052–0.108) 74.0 (32.0–148.0) 80–89 131.9 (98.4–172.0) 9.0 (6.3–12.9) 164.0 (106.0–247.0) 0.072 (0.051–0.104) 65.0 (32.0–134.0) 90 or Older 123.0 (83.8–168.5) 8.1 (5.5–11.8) 150.0 (92.0–222.5) 0.071 (0.048–0.098) 87.0 (35.5–188.5) Overall 144.3 (109.5–185.0) 10.9 (7.5–15.6) 219.0 (138.0–337.0) 0.081 (0.055–0.119) 66.0 (30.0–141.0) Pcuff Pcuff pressures initially increased then decreased with increasing age, reflecting the compensated/decompensated bladder function lifecycle (fig. 5). After reaching a peak pressure at patient age 62 years, Pcuff decreased by approximately 0.96 cmH2O with each year until age 90. Maximum Flow Rate Median maximum flow rate decreased from 14.5 ml per second in men younger than 50 years to 9.9 ml per second in men 70 to 79 years old. Overall, we observed that 55.8% of patients present with Qmax greater than 10 ml per second (fig. 3). Qmax less than 10 ml per second was recorded in 1,307 of 5,123 (25.5%) men less than 50 years old and 7,091 of 14,046 (50.5%) men 70 to 79 years old. From age 50 to 80 years the overall decrease in Qmax per decade is approximately 1.07 ml per second. Voided Volume Voided volume also decreased with increasing age, with a median of 302 ml for men younger than 50 years decreasing to a median volume of 194 ml for men 70 to 79 years old. From age 50 to 80 years VV decreased by approximately 3.64 ml with each year. Flow Rate Efficiency Flow rate efficiency is a calculated value dividing maximum flow rate by Pcuff pressure. As with all the other PFS parameters this ratio also demonstrated age related changes. As FRE decreases more pressure is required to generate flow, reflecting higher outlet resistance. For men younger than 50 years median FRE was 0.110, decreasing to 0.074 for men age 70 to 79 years. Post-Void Residual PVR data were available for 18,798 of 50,680 men (37.1%). PVR volume increased with age, with a median of 48 ml for men younger than 50 years up to a median volume of 194 ml for men 70 to 79 years old. PVR 150 ml or greater was recorded in 304 of 1,820 (16.7%) men less than 50 years old and 1,318 of 5,410 (24.4%) men 70 to 79 years old. Obstruction Category The NNN quadrant obstruction category also changed with age (p <0.0001). Men less than 50 years old were more than twice as likely as men 70 to 79 years old to be categorized as unobstructed (41.4% vs 20.2%), while men age 70 to 79 years were more than twice as likely as men younger than 50 years to be categorized as obstructed (34.1% vs 14.7%) (table 3). Table 3. NNN quadrant vs age cohort Age Grouping No. NNN Category (%) Totals Unobstructed High Pressure/High Flow Obstructed Low Pressure/Low Flow Younger than 50 2,119 (41.4) 1,684 (32.9) 755 (14.7) 565 (11.0) 5,123 (100.0) 50–59 2,588 (27.7) 3,365 (36.0) 2,277 (24.4) 1,110 (11.9) 9,340 (100.0) 60–69 3,752 (22.1) 5,650 (33.3) 5,232 (30.8) 2,332 (13.7) 16,966 (100.0) 70–79 2,838 (20.2) 4,067 (29.0) 4,792 (34.1) 2,349 (16.7) 14,046 (100.0) 80–89 790 (18.4) 1,011 (23.6) 1,483 (34.6) 999 (23.3) 4,283 (100.0) 90 or Older 54 (15.6) 68 (19.6) 114 (32.9) 111 (32.0) 347 (100.0) Discussion In this observational, cross-sectional study we reviewed the voiding characteristics of more than 50,000 men with LUTS attributed to BPH as measured by their initial UroCuff Test during a diagnostic workup. These real-world urodynamic data from the U.S. patient population provide insight into the progression of this disease. The basis for this large scale study was to evaluate enough men presenting with LUTS to visualize the underlying urological patterns. We surmised that urological function deteriorates with age and we wanted to investigate the effects of age on urodynamic function. Our findings support those of long-standing natural history studies. In the U.S. the natural history of BPH is best evidenced by the observational studies of community dwelling men conducted in Olmsted County.16–18 These landmark studies evaluated the prevalence and progression of urinary characteristics in 2,115 randomly selected men who were followed for 12 years. They demonstrated that as men age, the severity of their urological symptoms and bother increase, maximum flow rates decrease and prostate growth rates increase. However, PFS was not included in Olmsted County Study and to our knowledge, there are no observational studies defining changes in bladder pressure with age. This large data set of initial PFS on male patients presenting with LUTS reflects the systematic changes that take place on a population basis in urodynamic parameters with advancing age, including decreased flow rates, voided volumes, flow rate efficiencies and increased PVR. The data also reveal the manner in which the bladder is affected by chronic obstruction on a population basis, with increasing pressures up until average age 62 years (compensation phase) followed by decreasing pressures (decompensation phase) (fig. 5). BPH is a progressive disease state in which outlet resistance typically increases over time as the prostatic urethra gradually narrows. Figure 6 demonstrates how the pressure flow relationship changes in chronically obstructed patients on a population basis. Patients presenting in their 70s and older are 1.7 times more likely to be categorized as low pressure-low flow than patients in their 50s or younger. Conversely, patients in their 50s or younger are more than twice as likely to present as unobstructed and 1.2 times more likely to present as high pressure-high flow as patients in their 70s or older. Overall, as patients age, flow rates decrease by a higher percentage than their pressures decrease, reflecting a bending of the pressure flow relationship caused by more significant outlet obstruction. Figure 6. Typical progression of pressure flow relationship over time as BPH increases Given the changes that occur over time, the value of earlier bladder outlet obstruction relieving procedures is more evident. The U.S. Veterans Affairs BPH Cooperative Study Group highlighted the detrimental effects of delaying surgery in men with moderate symptoms of BPH.19 More recently, Young et al published a 20-year observational series demonstrating that in 2010, men presenting for surgery were older, sicker and had more postoperative complications than in 1990.20,21 After surgery the percentage of men with bladder dysfunction, either persistence storage LUTS or failure to void requiring long-term intermittent or indwelling catheterization, markedly increased from 1% to 7.9%, and 2% to 11.5%, respectively. Our aggregated PFS data on more than 50,000 patients presenting with LUTS reveal that underlying deterioration in bladder function occurs as men enter their 60s. This study supports the theory that bladder dysfunction may contribute to suboptimal treatment outcomes in older patients. The UroCuff technique offers several advantages over traditional catheterized cystometry studies using artificial filling. Artificial filling often results in bladder overfilling, provoked detrusor contractions, excessive voiding pressure and voiding volumes, thus providing data that may not reflect actual clinical symptoms.22 Artificial media such as water or saline (instead of urine) have been shown to affect pressure and flow rate.23 The presence of a catheter in the bladder impacts sensation during filling by irritating the bladder neck or retards flow rate during void by occluding the urethra.24 In addition, the placement of an abdominal channel catheter in the rectum has been shown to cause vasovagal syncope.25 The data available for this study were limited to the information entered and stored in the Complete Urodynamics instrument. Diagnosis, symptom assessment and treatment outcome data were not available, which consequently restricted the application of selection criteria and analysis. The population in this study was clinic based, exclusively including men who presented in urology practices with LUTS for whom a PFS was conducted. Therefore, these findings cannot be applied to a normal population, and as diagnosis was not available, we cannot conclude that these data represent only patients with BPH. This was a cross-sectional study design intended to collect data about individuals at 1 time point, and while cross-sectional studies are an efficient method of quantifying the prevalence of a disease or risk factor, they can only establish an association between variables. This study is limited in that it only provides PFS data and the relationship to age but cannot demonstrate causality. Future studies that include additional diagnostic and outcome data are needed. Conclusions Patients with LUTS/BPH represent, on average, a third of all urology patient visits in our practices. The LUTS/BPH disease state is best managed by careful assessment of patient symptoms, patient tolerance of symptoms, the nature of the outlet obstruction and the function of the bladder. The UroCuff Test improves clinical decision making and patient compliance, with the goal of ultimately improved treatment outcomes. Appendix 1. Data retrieved from the Complete Urodynamics Instrument Patient age at date of test (years) PcuffInt (cmH2O) Qmax (ml/sec) Voided Volume (ml) Newcastle Noninvasive Nomogram (NNN) Quadrant Assignment (Obstructed, Unobstructed, High Pressure/High Flow, Low Pressure/Low Flow) PVR (ml) Data stored in the Complete Urodynamics Instrument for each patient. Patient age must be entered into the Complete Urodynamics Instrument prior to the conduct of the UroCuff Test. Pcuffint, Qmax. VV and NNN are measured or calculated during the conduct of the test. PVR is an optional field. Appendix 2. Contributing authors Name Affiliation E-mail Alexis E. Te Weill Cornell Medicine [email protected]cornell.edu Steven N. Gange Summit Urology [email protected]com Jonathan Rubenstein Chesapeake Urology [email protected]md Michael Rotman Michael Rotman Urology [email protected]com Angelo J. Cambio Urologic Specialists of New England [email protected]com Richard E. D'Anna Arkansas Urology [email protected]com Mitchell B. Hollander Michigan Institute of Urology [email protected]com Judd Boczko WestMed [email protected]com Mark B. Lyon Associated Urological Specialists m.[email protected]com Karl J. Coutinho New Jersey Urology [email protected]com Yuk-Yuen Leung Urology Associates of Central California [email protected]net Wayne W. Kuang MD for Men [email protected]com Marc A. Mitchell The Doctors Clinic [email protected]com Edward L. Gheiler Urology Specialist Group [email protected]com Gregg R. Eure Urology of Virginia [email protected]com Nathan L. Graves North DFW Urology [email protected]net References 1. : The correlation between urodynamic and cystoscopic findings in elderly men with voiding complaints. J Urol 1996; 155: 1018. Link, Google Scholar 2. : Progressive bladder remodeling due to bladder outlet obstruction: a systematic review of morphological and molecular evidences in humans. BMC Urol 2018; 18: 15. Google Scholar 3. : Surgical management of lower urinary tract symptoms attributed to benign prostatic hyperplasia: AUA guideline. J Urol 2018; 200: 612. Link, Google Scholar 4. : Multisite evaluation of noninvasive bladder pressure flow recording using the penile cuff device: assessment of test-retest agreement. J Urol 2008; 180: 2515. Link, Google Scholar 5. : Noninvasive assessment of bladder contractility in men. J Urol 2004; 172: 1394. Link, Google Scholar 6. : Reproducibility of non-invasive urodynamics, using the cuff-uroflow, for the diagnosis of bladder outlet obstruction in males. 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ISBN 90-393-2771-8, 2001. Google Scholar 25. : Urodynamics in male LUTS: when are they necessary and how do we use them. Urol Clin North Am 2014; 41: 399. Google Scholar No direct or indirect commercial, personal, academic, political, religious or ethical incentive is associated with publishing this article. Editor's Note: This article is the fifth of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages 1391 and 1392. © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsRelated articlesJournal of UrologySep 28, 2020, 12:00:00 AMEditorial CommentJournal of UrologySep 28, 2020, 12:00:00 AMEditorial Comment Volume 204Issue 6December 2020Page: 1296-1304 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.Keywordslower urinary tract symptomsurodynamicsprostatic hyperplasiaMetricsAuthor Information Steven A. Kaplan Mt. Sinai, New York, New York More articles by this author Tobias S. Kohler Mayo Clinic, Rochester, Minnesota More articles by this author Sankar J. Kausik Chesapeake Urology, Belair, Maryland More articles by this author Expand All No direct or indirect commercial, personal, academic, political, religious or ethical incentive is associated with publishing this article. Editor's Note: This article is the fifth of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages 1391 and 1392. Advertisement Advertisement Loading ...