Anatomy of the perineal membrane as seen in magnetic resonance images of nulliparous women

Brandon, Catherine; Lewicky-Gaupp, Christina; Larson, Kindra; DeLancey, John O.L.

doi:10.1016/j.ajog.2009.03.004

Cited by 27 publications

(35 citation statements)

References 13 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…; Mirilas & Skandalakis, ; Stein & DeLancey, ; Brandon et al. ), but is also present, albeit less well‐developed, in males (Figs A–C and A). We, therefore, advocate that a middle compartment is acknowledged in both females and males.…”

Section: Discussionmentioning

confidence: 93%

Architecture of structures in the urogenital triangle of young adult males; comparison with females

Dabhoiwala

Hagoort

et al. 2018

Journal of Anatomy

View full text Add to dashboard Cite

The fibro‐muscular architecture of the urogenital triangle remains contentious. Reasons are small size of the constituting structures and poor visibility with most imaging methods. We reinvestigated the area in serial sections of three males (21–38 years old) of the American and Chinese Visible Human Projects and two 26‐week‐old male fetuses, and compared the findings with earlier observations in females. The mass of the levator ani muscle was approximately twofold smaller and its funnel shape steeper in males than females. In the levator hiatus, a strand of the smooth longitudinal muscle layer of the rectum, the ‘rectourethral (RU) muscle’, extended anteriorly from the anorectal bend to the penile bulb. Fibrous tissue that formed in the inferior reach of the fetal RU muscle identified the location of the developing perineal body (PB) and divided the muscle into posterior ‘rectoperineal’ and anterior ‘deep perineal’ portions. In males, the PB remained small and bipartite, so that the RU muscle presented as an undivided midline structure. The well‐developed female PB, instead, intertwined with the deep perineal muscle and both structures passed the vagina bilaterally to form the perineal membrane in the posterior portion of the urogenital triangle. The urethral rhabdosphincter extended in the anterior portion of the urogenital triangle between the penile bulb inferiorly and the bladder neck superiorly, and consisted of a well‐developed circular ‘membranous’ portion with bilateral posteroinferior ‘wings’ and a thinner ‘prostatic’ portion on the prostate anterior side. In men, muscles occupy the urogenital triangle, but additional tightening of the locally fibrous adipose tissue by the superficial transverse perineal muscle appears necessary to generate functional support in women. An interactive 3D pdf file with these anatomical details (available online) should allow more accurate interpretation of ultrasound, computed tomography and magnetic resonance images.

show abstract

Section: Discussionmentioning

confidence: 93%

Architecture of structures in the urogenital triangle of young adult males; comparison with females

Dabhoiwala

Hagoort

et al. 2018

Journal of Anatomy

View full text Add to dashboard Cite

show abstract

“…Each structure was traced using the most clearly visible axial and/or coronal plane images and lofted into a 3D virtual model based on our previous anatomic work (Brandon et al, 2009; Hsu et al, 2005; Hsu et al, 2008b; Larson et al, 2010b; Margulies et al, 2006). The volumetric 3D model was imported into Imageware (version 13.0; Siemens Product Lifecycle Management Software Inc., 2008).…”

Section: Methodsmentioning

confidence: 99%

A multi-compartment 3-D finite element model of rectocele and its interaction with cystocele

Luo

Chen

Fenner

et al. 2015

Journal of Biomechanics

Self Cite

View full text Add to dashboard Cite

We developed a subject-specific 3-D finite element model to understand the mechanics underlying formation of female pelvic organ prolapse, specifically a rectocele and its interaction with a cystocele. The model was created from MRI 3-D geometry of a healthy 45 year-old multiparous woman. It included anterior and posterior vaginal walls, levator ani muscle, cardinal and uterosacral ligaments, anterior and posterior arcus tendineus fascia pelvis, arcus tendineus levator ani, perineal body, perineal membrane and anal sphincter. Material properties were mostly from the literature. Tissue impairment was modeled as decreased tissue stiffness based on previous clinical studies. Model equations were solved using Abaqus v 6.11. The sensitivity of anterior and posterior vaginal wall geometry was calculated for different combinations tissue impairments under increasing intraabdominal pressure. Prolapse size was reported as POP-Q point at point Bp for rectocele and point Ba for cystocele. Results show that a rectocele resulted from impairments of the levator ani and posterior compartment support. For 20% levator and 85% posterior support impairments, simulated rectocele size (at POP-Q point: Bp) increased 0.29 mm/cm H2O without apical impairment and 0.36 mm/cm H2O with 60% apical impairment, as intraabdominal pressures increased from 0 to 150 cm H2O. Apical support impairment could result in the development of either a cystocele or rectocele. Simulated repair of posterior compartment support decreased rectocele but increased a preexisting cystocele. We conclude that development of rectocele and cystocele depend on the presence of anterior, posterior, levator and/or or apical support impairments, as well as the interaction of the prolapse with the opposing compartment.

show abstract

“…This sample size proved adequate to reveal typical structural features and relationships in normal women. 9, 10 All subjects gave informed written consent in accordance with the Institutional Review Board’s guidelines.…”

Section: Case Notesmentioning

confidence: 99%

See it in 3D!

Ramanah

Berger

Chen

et al. 2012

American Journal of Obstetrics and Gynecology

Self Cite

View full text Add to dashboard Cite

Anatomy of the perineal membrane as seen in magnetic resonance images of nulliparous women

Cited by 27 publications

References 13 publications

Architecture of structures in the urogenital triangle of young adult males; comparison with females

Architecture of structures in the urogenital triangle of young adult males; comparison with females

A multi-compartment 3-D finite element model of rectocele and its interaction with cystocele

See it in 3D!

Contact Info

Product

Resources

About