The potential value of ultrasound shear wave elastography in assessing functional defecation disorders / 中华消化杂志

ABSTRACT

Objective:To preliminary explore the potential application value of ultrasound shear wave elastography (SWE) in assessing functional defecation disorders compared with anorectal manometry and X-ray defecography.Methods:From July 2022 to December 2022, the results of SWE, anorectal manometry and X-ray defecography of 39 patients with functional defecation disorders visited Sir Run Run Shaw Hospital, School of Medicine of Zhejiang University were retrospectively analyzed. Non-parametric tests were used to analyze the changes in elastic modulus values of anorectal muscle groups at different phase.Chi-square test and Bland-Altman plots were used to assess the consistency between SWE, X-ray defecography and anorectal manometry in evaluating spastic pelvic floor syndrome, as well as the changes in the anorectal angle measured by SWE and X-ray defecography (from resting phase to contraction phase, resting phase to strain phase (Valsalval maneuver).Results:The elastic modulus values measured by SWE of the puborectalis muscle, internal anal sphincter, and external anal sphincter of patients with functional defecation disorders during strain phase were 32.4 kPa (19.1 kPa, 60.3 kPa), 25.3 kPa (17.0 kPa, 53.8 kPa), and 28.6 kPa (21.3 kPa, 55.1 kPa), respectively, which had no statistically significant differences compared to elastic modulus values in resting phase (33.5 kPa (22.1 kPa, 44.9 kPa), 28.9 kPa (22.4 kPa, 45.1 kPa), and 32.4 kPa (23.1 kPa, 49.4 kPa), all P>0.05). The consistency between SWE and X-ray defecography in the diagnosis of spastic pelvic floor syndrome was poor (Kappa=0.190). The consistency between SWE and anorectal manometry in the diagnosis of dyssynergic defecation was poor (Kappa=0.160). The differences in the changes of anorectal angle detected by SWE and X-ray defecography were within the 95% consistency limit ( P=0.429 and 0.582). Conclusion:SWE is sensitive in evaluating changes in anorectal angle, and it shows good consistency with defecography in assessing angle changes.