[Predictive factors for vaginal birth after cesarean section]. / Quels facteurs influencent la voie d'accouchement en cas de tentative de voie basse sur utérus cicatriciel ?

OBJECTIVES: Determination of predictive factors of vaginal delivery in women with a history of caesarean section undergoing a trial of labor. MATERIALS AND METHODS: Relevant studies were identified through Medline, and the Cochrane databases 1980-2012. Recommendations from the French and foreign obstetrical societies or colleges have been consulted. RESULTS: In France in 2010, a trial of labor was attempted in 49 % with 75 % successful rate (EL2). The site of delivery does not appear to influence the rate of successful trial of labor (EL3). Two factors are strongly associated with vaginal birth after caesarean (VBAC): prior history of vaginal delivery and spontaneous labor (EL2). Many factors appear to decrease the rate of VBAC: maternal age above 40 years (EL3), body mass index greater than 30 kg/m(2) (EL3), birth weights greater than 4000 g (EL3), unfortunately, prediction of macrosomia seems to be inaccurate. Induction of labor with pharmacological (prostaglandins and oxytocin) and mechanical methods (Foley catheter) decreased rate of successful VBAC (EL2). The use of pelvimetry to accept or avoid trial of labor, increase the risk of elective caesarean section (EL2) and should therefore not be recommended (grade C). Nomograms are not accurate to predict fail trial of labor as its clinical relevance is limited and has not yet evaluated in French population (expert opinion). CONCLUSION: After caesarean, trial of labor is associated with 75 % successful rate. Two factors are strongly associated with VBAC: a prior history of vaginal delivery and spontaneous labor.

Mechanical properties of hyaline and repair cartilage studied by nanoindentation.

Articular cartilage is a highly organized tissue that is well adapted to the functional demands in joints but difficult to replicate via tissue engineering or regeneration. Its viscoelastic properties allow cartilage to adapt to both slow and rapid mechanical loading. Several cartilage repair strategies that aim to restore tissue and protect it from further degeneration have been introduced. The key to their success is the quality of the newly formed tissue. In this study, periosteal cells loaded on a scaffold were used to repair large partial-thickness cartilage defects in the knee joint of miniature pigs. The repair cartilage was analyzed 26 weeks after surgery and compared both morphologically and mechanically with healthy hyaline cartilage. Contact stiffness, reduced modulus and hardness as key mechanical properties were examined in vitro by nanoindentation in phosphate-buffered saline at room temperature. In addition, the influence of tissue fixation with paraformaldehyde on the biomechanical properties was investigated. Although the repair process resulted in the formation of a stable fibrocartilaginous tissue, its contact stiffness was lower than that of hyaline cartilage by a factor of 10. Fixation with paraformaldehyde significantly increased the stiffness of cartilaginous tissue by one order of magnitude, and therefore, should not be used when studying biomechanical properties of cartilage. Our study suggests a sensitive method for measuring the contact stiffness of articular cartilage and demonstrates the importance of mechanical analysis for proper evaluation of the success of cartilage repair strategies.

Remodeling of myocardium and arteries by chronic angiotensin converting enzyme inhibition in hypertensive patients.

AIM: To investigate changes in left ventricular hypertrophy and diastolic function in hypertensive patients treated with an angiotensin converting enzyme (ACE) inhibitor. METHODS: Structural and functional changes in the heart and iliac artery were studied by echocardiography and intraluminal ultrasound in 15 hypertensive patients following 6 months of treatment with the ACE inhibitor quinapril at 10-40 mg/day. RESULTS: Systolic/diastolic blood pressure was reduced from 156/100 mmHg to 128/82 mmHg within 2 months and remained stable during the next 4 months of the study. The left ventricular mass index was significantly reduced from 174 +/- 86 to 161 +/- 75 g/m2 (-7.4%, P < 0.05). The reduction in left ventricular hypertrophy was associated with a trend towards an improvement in diastolic function, but left ventricular systolic function did not change. There was a 3.9% increase in iliac lumen area and a significant decrease of 10.7% (P < 0.05) in the ratio between the intimal-medial and lumen area, which represents a decrease in wall thickness. A key result was a statistically significant decrease in pulse-wave velocity, from 13.7 +/- 2.6 to 12.1 +/- 2.0 m/s, and in the modulus of elasticity, from 20.5 +/- 7.2 to 15.8 +/- 5.6 x 10(4) N/m2 (P < 0.05). CONCLUSION: The present study demonstrates that 6 months of treatment with an ACE inhibitor induced a significant regression in left ventricular hypertrophy and a reduction in wall thickness. In addition, the results indicate that chronic ACE inhibition can decrease the stiffness of large elastic arteries independently of a reduction in blood pressure.