Warping of the levator hiatus: how significant is it?

Abstract

Objectives The levator hiatus is the largest potential hernial portal in the human body. Excessive distensibility is associated with female pelvic organ prolapse (POP

Is curved three‐dimensional ultrasound reconstruction needed to assess the warped pelvic floor plane?

“…Very limited data exist on the craniocaudal displacement of the LAM. In a recent study, Dietz and colleagues addressed this issue. Similarly to our study, they assessed warping as the difference between the plane of minimal hiatal dimensions in the midsagittal and coronal planes.…”

“…Warping was calculated on the coronal plane (Figure , Plane B) as the distance between the traditional linear plane of minimal hiatal dimensions and the warped plane of minimal hiatal dimensions. The traditional reconstructed linear plane of minimal hiatal dimensions was measured as the line extending from the posterior aspect of the pubic symphysis to the anorectal angle, as used previously by most authors working in this field. This plane was termed the ‘expected’ plane of minimal hiatal dimensions (e‐PMHD) in the present study, as it assumes that the true plane of minimal hiatal dimensions runs arbitrarily within a maximum craniocaudal displacement of 1–2 cm between the pubic symphysis and the anorectal angle.…”

“…The linear (flat) plane running between these two reference points has been termed the plane of minimal hiatal dimensions. Although all three‐dimensional (3D) techniques used to date for the assessment of levator hiatal area reconstruct a linear plane, it has been shown that such a plane is not flat but rather non‐Euclidean or ‘warped’, mainly owing to caudal bulging of the LAM, which can be seen predominantly on maximal Valsalva maneuver. Although it has been suggested recently that such caudal bulging is minimal and would thus be contained within the 1–2‐cm slice used arbitrarily by some 3D‐reconstruction techniques, no attempt has been made to depict the anatomical curved shape of the LAM.…”

Which factors are associated with anal incontinence after obstetric anal sphincter injury?

“…Levator avulsion was defined as an abnormal muscle insertion in three central slices on tomographic ultrasound imaging (reference slice and the 2.5‐ and 5‐mm cranial slices). The hiatal area was measured in a rendered volume during maximum Valsalva maneuver 16 . Levator ballooning was defined as a hiatal area of > 25 cm 2;17 .…”