Intraurethral Ultrasonography: Correlation of Urethral Anatomy with Functional Urodynamic Parameters in Stress Incontinent Women

Abstract

To determine whether differences in functional urodynamic parameters can be explained by changes in urethral anatomy, 39 patients underwent intraurethral ultrasonography to obtain a 360 degree view of the urethra. The point of maximal rhabdosphincter thickness was identified in all patients. The thickness, circumference and area of the urethral smooth and skeletal muscle layers were calculated. Data from patient histories and urodynamic evaluations were compared with this anatomical survey. The urodynamic diagnoses were as follows: 10 patients were normal, 24 had genuine stress incontinence and 5 had intrinsic sphincter deficiency. These patients had decreasing rhabdosphincter thicknesses of 3.91, 3.35 and 2.70 mm (P = 0.048). A weak linear relationship was found between maximal urethral closure pressure and rhabdosphincter (r = 0.40, P = 0.013) and longitudinal smooth muscle (r = 0.35, P=0.027) thickness. It was concluded that a loss of urethral resistance as measured by maximal urethral closure pressure is associated with changes in urethral anatomy identified by intraurethral ultrasonography.

Intraurethral sonography and the test‐retest reliability of urethral sphincter measurements in women

“…On the basis of previous work correlating urethral sphincter morphologic characteristics with functional urodynamic parameters, 8 several different measurements were taken ( Figure 3). The diameters of the urethra and longitudinal smooth muscle were measured along a line passing through the transducer's center to the calipers positioned on the outer surface of each structure.…”

“…8 The results showed that healthy subjects had thicker rhabdosphincters than did subjects with genuine stress incontinence, and subjects with genuine stress incontinence had thicker rhabCorrespondence to: M. Heit…”

“…Finally, longitudinal smooth muscle thickness was associated with maximal urethral closure pressure 9,10 and leak-point pressure 11 cutoff values used to differentiate genuine stress incontinence from intrinsic sphincter deficiency. 8 New techniques allow researchers to gain better insight into the pathophysiologic processes underlying diseases or disorders. It is hoped that a better understanding of these processes will translate into better outcomes for patients.…”

Recommandations pour la pratique de l’imagerie dans l’évaluation d’une incontinence urinaire féminine non neurologique

“…De même, Kuo, par voie transrectale, observe dans l'IUE de type III démontrée par des études VUD une diminution de la couche périphérique hypoéchogène assimilée au muscle strié comparativement aux sujets sans incontinence [36]. D'autres études échographiques avec doppler couleur ou par voie intra-urétrale s'attachent à étudier les modifications morphologiques du sphincter urétral mais ne débouchent pas actuellement sur une utilisation pratique [35,[37][38][39].…”

Basic science and translational research in female pelvic floor disorders: Proceedings of an NIH‐sponsored meeting

“…For example, transurethral ultrasound of the urethra can be combined with functional tests, such as EMG, to better understand the structure and functioning of the urethra [Fischer et al, 2000]. Ultrasound can also be compared with urodynamic ¢ndings [Heit, 2000], although studies of this nature may prove disappointing, not because of limitations associated with the imaging tests but because of limitations of urodynamic testing. It is even possible to combine functional and imaging tests, much as positron emission tomography (PET) scanning accomplished for central neuroanatomy and function.…”