Persistent occiput posterior position and stress distribution in levator ani muscle during vaginal delivery computed by a finite element model

Havelková, Linda; Krofta, Ladislav; Kochová, Petra; Liška, Václav; Kališ, Vladimír; Feyereisl, Jaroslav

doi:10.1007/s00192-019-03997-8

Cited by 14 publications

(12 citation statements)

References 29 publications

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“…Computational models describing deformations of the levator ani muscle during vaginal birth have been developed [19][20][21][22]. Although the existing models provide an insight into parturition, they are restricted by numerous assumptions and predominantly by the fact that they are limited to levator ani muscle.…”

Section: For the Antepartum Conditions In Right Imagementioning

confidence: 99%

Feasibility and safety of antepartum tactile imaging

et al. 2020

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Introduction and hypothesis Quantitative characterization of the birth canal and critical structures before delivery may provide risk assessment for maternal birth injury. The objective of this study was to explore imaging capability of an antepartum tactile imaging (ATI) probe. Methods Twenty randomly selected women older than 21 years with completed 35th week of pregnancy and a premise of vaginal delivery were enrolled in the feasibility study. The biomechanical data were acquired using the ATI probe with a double-curved surface, shaped according to the fetal skull and equipped with 168 tactile sensors and an electromagnetic motion tracking sensor. Software package COMSOL Multiphysics was used for finite element modeling. Subjects were asked for assessment of pain and comfort levels experienced during the ATI examination. Results All 20 nulliparous women were successfully examined with the ATI. Mean age was 27.8 ± 4.1 years, BMI 30.7 ± 5.8, and week of pregnancy 38.8 ± 1.4. Biomechanical mapping with the ATI allowed real-time observation of the probe location, applied load to the vaginal walls, and a 3D tactile image composition. The nonlinear finite element model describing the stress–strain relationship of the pelvic tissue was developed and used for calculation of Young’s modulus (E). Average perineal elastic modulus was 11.1 ± 4.3 kPa, levator ani 4.8 ± 2.4 kPa, and symphysis–perineum distance was 30.1 ± 6.9 mm. The pain assessment level for the ATI examination was 2.1 ± 0.8 (scale 1–4); the comfort level was 2.05 ± 0.69 (scale 1–3). Conclusions The antepartum examination with the ATI probe allowed measurement of the tissue elasticity and anatomical distances. The pain level was low and the comfort level was comparable with manual palpation.

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Section: For the Antepartum Conditions In Right Imagementioning

confidence: 99%

Feasibility and safety of antepartum tactile imaging

et al. 2020

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“…A three-dimensional computational model of the female pelvic floor was created and used to simulate vaginal birth. The model was based on live-subject MRI data (a 25-year-old nulliparous woman with a BMI of 21.9 kg/m 2 and no pelvic floor dysfunction symptoms or displacement) using 130 previously described axial 3-T MR images [15,18]. The initial geometry was reconstructed using free semiautomatic 3D-Slicer software (3.0, BWH, Boston, MA, USA).…”

Section: Methodsmentioning

confidence: 99%

“…The bony pelvis and the three components of the LAM (pubovisceral muscle, PVM; puborectal muscle, PRM; iliococcygeus muscle, ICM) were adapted from our previous modeling study using MRI data as well [15,18]. The pelvis was constructed with 2D triangular mesh as a rigid nondeformable body, while the deformable muscle was modeled by 3D tetrahedral mesh.…”

Section: Developing the Biomechanical Model Of Bony Pelvis And Levator Ani Musclesmentioning

confidence: 99%

“…During vaginal birth, the LAM undergoes extremely large deformation [8,10,15,17,18]. Therefore, similar to our previous studies and using the same parameters, the hyperelastic nonlinear Ogden material model was used [18,20]. The material parameters were based on experimental measurements of porcine muscle samples.…”

Section: Developing the Biomechanical Model Of Bony Pelvis And Levator Ani Musclesmentioning

confidence: 99%

“…These studies reported an LAM stretch ratio ranging between 1.63 and 3.5:1 [8,9]. The maximum LAM stretch was reported to occur when the leading margin of the fetal head was between 5 and 11 cm below the level of the ischial spines [9,15,17,18]. Jing et al developed a model incorporating the LAM and perineum.…”

Section: Introductionmentioning

confidence: 99%

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Finite element modeling of maximum stress in pelvic floor structures during the head expulsion (FINESSE) study

et al. 2021

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Introduction and hypothesis Several studies have assessed birth-related deformations of the levator ani muscle (LAM) and perineum on models that depicted these elements in isolation. The main aim of this study was to develop a complex female pelvic floor computational model using the finite element method to evaluate points and timing of maximum stress at the LAM and perineum in relation to the birth process. Methods A three-dimensional computational model of the female pelvic floor was created and used to simulate vaginal birth based on data from previously described real-life MRI scans. We developed three models: model A (LAM without perineum); model B (perineum without LAM); model C (a combined model with both structures). Results The maximum stress in the LAM was achieved when the vertex was 9 cm below the ischial spines and measured 37.3 MPa in model A and 88.7 MPa in model C. The maximum stress in the perineum occurred at the time of distension by the suboocipito-frontal diameter and reached 86.7 MPa and 119.6 MPa in models B and C, respectively, while the stress in the posterior fourchette caused by the suboccipito-bregmatic diameter measured 36.9 MPa for model B and 39.8 MPa for model C. Conclusions Including perineal structures in a computational birth model simulation affects the level of stress at the LAM. The maximum stress at the LAM and perineum seems to occur when the head is lower than previously anticipated.

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