Perineal elasticity Dotaz Zobrazit nápovědu
OBJECTIVE: The perineal body connects muscles from the pelvic floor and is critical for support of the lower part of the vagina and proper function of the anal canal. We determined mechanical parameters and volume fractions of main components of the human female postmenopausal perineal body. METHODS: The specimens were taken from 15 fresh female cadavers (age 74 ± 10, mean ± standard deviation). Seventy-five specimens from five regions of the perineal body were processed histologically to assess volume fractions of tissue components using stereological point testing grid. Fifteen specimens taken from the midline region were loaded uniaxially with 6 mm/min velocity until tissue rupture to determine Young's modulus of elasticity, ultimate stresses, and strains. RESULTS: The perineal body was composed of collagen (29%), adipose cells (27%), elastin (7%), smooth muscle (11%), and skeletal muscle (3%). The residual tissue (19%) constituted mostly peripheral nerves, lumina of blood vessels, fibroblasts, and fibrocytes. Young's modulus of elasticity at midline region was 18 kPa (median) at small and 232 kPa at large deformations, respectively. The ultimate stress was 172 kPa and the ultimate strain was 1.4. CONCLUSIONS: We determined the structural and mechanical parameters of the perineal body. The resultant data could be used as input for models simulating pelvic floor prolapse or dysfunction.
- MeSH
- anální kanál MeSH
- biomechanika fyziologie MeSH
- elastin analýza MeSH
- hladké svalstvo anatomie a histologie MeSH
- kolagen analýza MeSH
- kosterní svaly anatomie a histologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mrtvola MeSH
- pánevní dno anatomie a histologie fyziologie chirurgie MeSH
- perineum anatomie a histologie fyziologie chirurgie MeSH
- postmenopauza fyziologie MeSH
- prolaps pánevních orgánů patofyziologie MeSH
- pružnost fyziologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- tuková tkáň anatomie a histologie MeSH
- vagina MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- elastin MeSH
- kolagen MeSH
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.
- Klíčová slova
- Biomechanics of parturition, Elastography, Finite element model, Perineal elasticity, Tactile imaging,
- MeSH
- dospělí MeSH
- elastografie * MeSH
- lidé MeSH
- mladý dospělý MeSH
- pánevní dno * diagnostické zobrazování MeSH
- perineum diagnostické zobrazování MeSH
- porod MeSH
- studie proveditelnosti MeSH
- těhotenství MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The mechanical properties and microstructure of the perineal body are important for the improvement of numerical models of pelvic organs. We determined the mechanical parameters and volume fractions of the ewe perineal body as an animal model. METHODS: The 39 specimens of 13 pregnant swifter ewes delivering by cesarean section (aged 2 years, weight 61.2 ± 6.2 kg (mean ± standard deviation) and 24 specimens of 8 postmenopausal swifter ewes 150 days after surgical ovariectomy (aged 7 years, 58.6 ± 4.6 kg)) were loaded uniaxially to determine Young's moduli of elasticity in the small (E0) and large (E1) deformation regions, and ultimate stresses and strains. The 63 adjacent tissue samples were processed histologically to assess volume fractions of smooth and skeletal muscle, adipose cells, elastin, and type I collagen using a stereological point testing grid. We compared the structural and mechanical differences along the ewe perineal body, and between pregnant and postmenopausal groups. RESULTS: The pregnant/postmenopausal perineal body was composed of smooth muscle (12/14%; median), skeletal muscle (12/16%), collagen (10/23%), elastin (8/7%), and adipose cells (6/6%). The E0 was 37/11 kPa (median), E1 was 0.97/1.04 MPa, ultimate stress was 0.55/0.59 MPa, and ultimate strain was 0.90/0.87 for pregnant/postmenopausal perineal body. The perineal body showed a structural and mechanical stability across the sites. The pregnant ewes had a higher amount of skeletal muscle, higher E0, and a less amount of collagen when compared with postmenopausal ewes. CONCLUSIONS: The data can be used as input for models simulating vaginal delivery, pelvic floor prolapsed, or dysfunction.
- MeSH
- biomechanika MeSH
- elastin analýza MeSH
- hladké svalstvo anatomie a histologie fyziologie MeSH
- kolagen analýza MeSH
- kosterní svaly anatomie a histologie fyziologie MeSH
- modely u zvířat MeSH
- ovce MeSH
- perineum anatomie a histologie fyziologie MeSH
- postmenopauza MeSH
- těhotenství MeSH
- tukové buňky MeSH
- zvířata MeSH
- Check Tag
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- elastin MeSH
- kolagen MeSH
AIM: To analyze reasons for episiotomy use in vaginal delivery among obstetricians and midwives. Consecutively, to indentify disputable indications for its use based on published research in order to facilitate the decrease in frequency of this operation, while preserving high quality of obstetrical care. METHODS: Reasons for mediolateral episiotomy use were recorded by obstetricians and midwives after each vaginal delivery with episiotomy at the Ob&Gyn Department of the Charles University Hospital in Pilsen in the period of February 2006 - June 2007. The main reason and all reasons for episiotomy use were evaluated separately. RESULTS: The reason for episiotomy use was recorded in 1069 cases (93%) out of a total of 1150 vaginal deliveries, in which mediolateral episiotomy was performed (42% of all vaginal deliveries). The most common group of main reasons for episiotomy use was a concern about postpartum pelvic floor functional impairment (624, 58% of episiotomies), especially a rigid, non-elastic perineum (401, 37%). Fetal distress (181, 17%) and abnormalities of the expulsive forces/uncooperative parturient (109, 10%) followed. When evaluating all (including secondary) reasons, the most common groups of reasons for episiotomy use were the effort of pelvic floor functionality preservation (871, 50%), abnormalities of the expulsive forces/uncooperative parturient (354, 20%) and fetal distress (253, 15%). When evaluating episiotomies performed by obstetricians and midwives separately, the concern about postpartum pelvic floor functionality prevailed in midwives (81% vs. 39% of episiotomies performed primarily for this reason). Conversely, the obstetricians performed episiotomy more frequently for fetal distress (28% vs. 4%). CONCLUSION: In view of the fact that midwives attend only physiological deliveries in our department, the spectrum of reasons for episiotomy use among midwives is narrower and the concern about postpartum pelvic floor functionality dominates. Currently, the concern about postpartum pelvic floor functionality should not be considered a legitimate indication for episiotomy use. The fact that 624 (58%) episiotomies were performed for this reason represents a significant reserve for a decrease in the frequency of episiotomy use. The reduction should be possible primarily among midwives (81% of all main reasons for episiotomy use in the midwive group, i.e. 37% of all episiotomies performed). The analysis of reasons for episiotomy use is an important step in reduction of episiotomy rates while preserving or improving the standard of treatment provided.
