Mechanical properties of pelvic soft tissue of young women and impact of aging.

INTRODUCTION AND HYPOTHESIS: The female pelvic floor is a complex network of ligaments and muscles whose mechanical properties have not been completely understood. The goal of this study is to understand the biomechanical properties of the pelvic floor tissues of young women and the impact of aging. METHODS: Biomechanical uniaxial tension tests were performed on pelvic floor tissues (ligaments and organs) of six young female cadavers (average 29 years old). Results have been analyzed in order to define the characteristics of the mechanical properties of young pelvic soft tissues. Results have been compared with those in the literature in order to understand the similarities and discrepancies between young and old patients. RESULTS: Damageable, nonlinear elastic biomechanical behavior is observed. The variation in stiffness among the pelvic floor organs could be shown. Ligaments and the vaginal wall are the most rigid organs, whereas the rectum and bladder tend to be less rigid (approximately two times less rigid for small deformations and three times less rigid for large deformations). This study shows that ligaments and the vaginal wall of young women have similar mechanical behavior while those of older women differ. Furthermore, young women's tissues differ slightly from older women's tissues. CONCLUSIONS: Results show that aging and possibly diverse "trauma" have an impact on modifying the mechanical behavior of pelvic floor tissues. Over time pelvic floor ligaments and vaginal tissues will differentiate and acquire different mechanical behavior, as seen within the literature in older cadavers.

Biomechanical and histological evaluation of abdominal wall compliance with intraperitoneal onlay mesh implants in rabbits: a comparison of six different state-of-the-art meshes.

BACKGROUND: An ideal prosthetic mesh for incisional hernia repair should mimic the anisotropic compliance of the abdominal wall, and at lower loads should exhibit higher distensibility without impairment of safety at higher loads. This study evaluated the biomechanical properties of six meshes in a rabbit model. METHODS: New Zealand white rabbits were used for this study. Two meshes of the same brand (Ethicon Physiomesh™, Bard Composix(®) L/P, Gore Dualmesh(®), Bard Sepramesh(®), Ethicon Proceed(®) or Parietex™ Composite) were implanted into each animal for assessment of intra-abdominal hernia repair, with a total of ten meshes per group. Twelve weeks after implantation, the abdominal walls with ingrown meshes were harvested and examined biomechanically with a plunger test. The mesh-tissue compliance was evaluated by the forces exerted at given displacements and also described through a simple mathematical approximation. Abdominal wall samples were collected for histopathology, cell turnover and morphometry. RESULTS: No mesh-related complications were seen. The adhesion score was significantly higher in Bard Composix(®) L/P and Ethicon Proceed(®) meshes. Significant shrinkage was seen in Gore Dualmesh(®) and Parietex™ Composite meshes. Physiomesh™ exhibited the highest compliance during plunger testing, characterized by lower, more physiological reaction forces against tissue displacement than the competitor meshes. In contrast, the safety modulus was comparable in all groups. Histology showed less collagen and less foreign body reaction in the Physiomesh™ samples contributing to patient's comfort. CONCLUSION: In terms of safety, this study showed no superiority of any single mesh. The comfort modulus however differed, being lowest in the newly developed Physiomesh™.

[Should Doppler echography in the diagnosis of the extra-cardiac sites of atherosclerosis be routine in patients with coronary disease? Apropos of 248 cases]. / La recherche, par échographie-doppler, des localisations extra-cardiaques de l'athérosclérose chez le coronarien doit-elle être systématique? A propos de 248 observations.

Doppler ultrasound investigation of cervical and aorto-iliac arteries, performed in 248 patients investigated by coronary angiography (including 80% with coronary heart disease: 23% single-vessel, 23% two-vessel and 34% three-vessel disease) confirmed the frequency of dissemination of the atheromatous process (in the cervical vessels: non-stenotic atheroma: 45%, significant single- or multi-vessel stenoses: 16%, in the aorto-iliac vessels: non-stenotic atheroma: 32.8%, significant stenoses: 17.2%), which has been known for a long time. The unreliability of clinical examination, the reliability, safety and low cost of ultrasound, the discovery of a considerable number of critical, potentially dangerous arterial lesions, some of which may require a surgical procedure or angioplasty (3.4%), the value of assessing, either before coronary angiography or before cardiac surgery, certain specific arterial territories such as the aortic bifurcation and subclavian vessels, justify systematic use of this examination in coronary patients, particularly before coronary angiography and always before coronary surgery.