Sachin Malde1, Arjun K Nambiar2, Roland Umbach3, Thomas B Lam4, Thorsten Bach5, Alexander Bachmann6, Marcus J Drake7, Mauro Gacci8, Christian Gratzke9, Stephan Madersbacher10, Charalampos Mamoulakis11, Kari A O Tikkinen12, Stavros Gravas13. 1. Department of Urology, Guy's and St Thomas' NHS Foundation Trust, London, UK. 2. Department of Urology, Freeman Hospital, Newcastle upon Tyne, UK. 3. Department of Urology, Klinikum Sindelfingen-Böblingen, Sindelfingen, Germany. 4. Academic Urology Unit, University of Aberdeen, Aberdeen, UK; Department of Urology, Aberdeen Royal Infirmary, Aberdeen, UK. 5. Department of Urology, Asklepios Hospital Harburg, Hamburg, Germany. 6. Department of Urology, University Hospital Bonn, Bonn, Germany. 7. School of Clinical Sciences, University of Bristol, Bristol, UK. 8. Department of Urology, University of Florence, AOUC - Careggi Hospital, Florence, Italy. 9. Department of Urology, Ludwig-Maximilians-University Munich, Munich, Germany. 10. Department of Urology, Kaiser Franz Josef Spital, Vienna, Austria. 11. Department of Urology, University General Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece. 12. Departments of Urology and Public Health, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 13. Department of Urology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece. Electronic address: sgravas2002@yahoo.com.
Abstract
CONTEXT: Several noninvasive tests have been developed for diagnosing bladder outlet obstruction (BOO) in men to avoid the burden and morbidity associated with invasive urodynamics. The diagnostic accuracy of these tests, however, remains uncertain. OBJECTIVE: To systematically review available evidence regarding the diagnostic accuracy of noninvasive tests in diagnosing BOO in men with lower urinary tract symptoms (LUTS) using a pressure-flow study as the reference standard. EVIDENCE ACQUISITION: The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central, Google Scholar, and WHO International Clinical Trials Registry Platform Search Portal databases were searched up to May 18, 2016. All studies reporting diagnostic accuracy for noninvasive tests for BOO or detrusor underactivity in men with LUTS compared to pressure-flow studies were included. Two reviewers independently screened all articles, searched the reference lists of retrieved articles, and performed the data extraction. The quality of evidence and risk of bias were assessed using the QUADAS-2 tool. EVIDENCE SYNTHESIS: The search yielded 2774 potentially relevant reports. After screening titles and abstracts, 53 reports were retrieved for full-text screening, of which 42 (recruiting a total of 4444 patients) were eligible. Overall, the results were predominantly based on findings from nonrandomised experimental studies and, within the limits of such study designs, the quality of evidence was typically moderate across the literature. Differences in noninvasive test threshold values and variations in the urodynamic definition of BOO between studies limited the comparability of the data. Detrusor wall thickness (median sensitivity 82%, specificity 92%), near-infrared spectroscopy (median sensitivity 85%, specificity 87%), and the penile cuff test (median sensitivity 88%, specificity 75%) were all found to have high sensitivity and specificity in diagnosing BOO. Uroflowmetry with a maximum flow rate of <10ml/s was reported to have lower median sensitivity and specificity of 68% and 70%, respectively. Intravesical prostatic protrusion of >10mm was reported to have similar diagnostic accuracy, with median sensitivity of 68% and specificity of 75%. CONCLUSIONS: According to the literature, a number of noninvasive tests have high sensitivity and specificity in diagnosing BOO in men. However, although the majority of studies have a low overall risk of bias, the available evidence is limited by heterogeneity. While several tests have shown promising results regarding noninvasive assessment of BOO, invasive urodynamics remain the gold standard. PATIENT SUMMARY: Urodynamics is an accurate but potentially uncomfortable test for patients in diagnosing bladder problems such as obstruction. We performed a thorough and comprehensive review of the literature to determine if there were less uncomfortable but equally effective alternatives to urodynamics for diagnosing bladder problems. We found that some simple tests appear to be promising, although they are not as accurate. Further research is needed before these tests are routinely used in place of urodynamics.
CONTEXT: Several noninvasive tests have been developed for diagnosing bladder outlet obstruction (BOO) in men to avoid the burden and morbidity associated with invasive urodynamics. The diagnostic accuracy of these tests, however, remains uncertain. OBJECTIVE: To systematically review available evidence regarding the diagnostic accuracy of noninvasive tests in diagnosing BOO in men with lower urinary tract symptoms (LUTS) using a pressure-flow study as the reference standard. EVIDENCE ACQUISITION: The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central, Google Scholar, and WHO International Clinical Trials Registry Platform Search Portal databases were searched up to May 18, 2016. All studies reporting diagnostic accuracy for noninvasive tests for BOO or detrusor underactivity in men with LUTS compared to pressure-flow studies were included. Two reviewers independently screened all articles, searched the reference lists of retrieved articles, and performed the data extraction. The quality of evidence and risk of bias were assessed using the QUADAS-2 tool. EVIDENCE SYNTHESIS: The search yielded 2774 potentially relevant reports. After screening titles and abstracts, 53 reports were retrieved for full-text screening, of which 42 (recruiting a total of 4444 patients) were eligible. Overall, the results were predominantly based on findings from nonrandomised experimental studies and, within the limits of such study designs, the quality of evidence was typically moderate across the literature. Differences in noninvasive test threshold values and variations in the urodynamic definition of BOO between studies limited the comparability of the data. Detrusor wall thickness (median sensitivity 82%, specificity 92%), near-infrared spectroscopy (median sensitivity 85%, specificity 87%), and the penile cuff test (median sensitivity 88%, specificity 75%) were all found to have high sensitivity and specificity in diagnosing BOO. Uroflowmetry with a maximum flow rate of <10ml/s was reported to have lower median sensitivity and specificity of 68% and 70%, respectively. Intravesical prostatic protrusion of >10mm was reported to have similar diagnostic accuracy, with median sensitivity of 68% and specificity of 75%. CONCLUSIONS: According to the literature, a number of noninvasive tests have high sensitivity and specificity in diagnosing BOO in men. However, although the majority of studies have a low overall risk of bias, the available evidence is limited by heterogeneity. While several tests have shown promising results regarding noninvasive assessment of BOO, invasive urodynamics remain the gold standard. PATIENT SUMMARY: Urodynamics is an accurate but potentially uncomfortable test for patients in diagnosing bladder problems such as obstruction. We performed a thorough and comprehensive review of the literature to determine if there were less uncomfortable but equally effective alternatives to urodynamics for diagnosing bladder problems. We found that some simple tests appear to be promising, although they are not as accurate. Further research is needed before these tests are routinely used in place of urodynamics.