Department of Obstetrics and Gynecology, Hammerfest Hospital, Hammerfest, Norway.
Ultrasound Obstet Gynecol. 2011 Mar;37(3):353-60. doi: 10.1002/uog.8873.
To explore the possibility of using transvaginal 3D ultrasound as a method of assessing the compartments of the anal canal during rest, to determine the effect of squeeze, and to compare these findings with those obtained using the endoanal technique in the same women.
Transvaginal 3D ultrasound was used in a cross-sectional study measuring the anal mucosa and sphincters during rest and squeeze in 20 nulligravida women, comparing the results with those of endoanal measurements. Measurements were also performed of the anal mucosa, anorectal curvature (ARC), and anovaginal angle (AVA) and distance (AVD).
Volume measurements of the anal mucosa were only possible using transvaginal ultrasound. The mean volume of the anal canal using the transvaginal technique was 7.93 (SD 2.26) and 7.34 (1.54) cm(3) during rest and squeeze, respectively (P = 0.082). The ARC became more acute (3.46 vs. 4.12°/mm, P = 0.031) during squeeze and AVA increased (31.7° vs. 35.8°, P = 0.010). The volume of the anal mucosa (3.12 cm(3)) did not change (P = 0.193), but was distorted during squeeze at the level of the puborectalis sling (P < 0.001 for upper cross-section and diameter). The anal canal was 1 cm longer (P < 0.001), the IAS volume larger (2.97 and 2.08 cm(3), P = 0.003), and the EAS volume smaller (1.85 and 3.96 cm(3), P < 0.001) using the 3D transvaginal technique compared with the endoanal measurements at rest, with similar differences observed on squeeze.
In contrast to the endoanal method, transvaginal 3D ultrasound provides a complete assessment of the anal canal, including the mucosa. This method seems suitable for functional studies such as in the present one, which shows that voluntary squeeze increases the angulation of the anal canal and distorts the bowel cross-section at the level of the puborectal muscle.
探讨经阴道三维超声在评估静息和收缩状态下肛门内、外括约肌各解剖间隙的可能性，比较该方法与腔内超声的结果。
采用经阴道三维超声对 20 例未生育女性进行研究，测量静息和收缩状态下的肛管和肛门内、外括约肌，将结果与腔内超声测量值进行比较。同时还对肛门内、外括约肌、肛直角（ARC）、阴道肛角度（AVA）和距离（AVD）进行了测量。
仅经阴道超声可进行黏膜体积的测量。经阴道技术测量的肛管静息和收缩时的平均体积分别为 7.93（SD 2.26）和 7.34（1.54）cm3（P = 0.082）。ARC 在收缩时变得更陡峭（3.46 比 4.12°/mm，P = 0.031），AVA 增加（31.7 比 35.8°，P = 0.010）。黏膜体积（3.12 cm3）无变化（P = 0.193），但在耻骨直肠肌吊带水平收缩时发生变形（上交叉和直径的 P 值均 < 0.001）。经阴道三维超声测量的肛管长度增加 1 cm（P < 0.001），内括约肌体积增大（2.97 和 2.08 cm3，P = 0.003），外括约肌体积减小（1.85 和 3.96 cm3，P < 0.001），与静息时腔内超声测量值相比，收缩时也存在类似差异。
与腔内超声方法相比，经阴道三维超声可全面评估肛门内、外括约肌，包括黏膜。该方法似乎适用于功能研究，如本研究显示，自主收缩增加肛管的角度，并在耻骨直肠肌水平扭曲肠管的横截面。
