Technical aspects of laparoscopic ovarian autograft in ewes after cryopreservation by slow-cooling protocol.

Iatrogenic ovarian failure and infertility are long term-term side effects of anticancerous gonadotoxic treatments in children or women of reproductive year. Ovarian cortex cryopreservation can be a solution to preserve immature germinal cells before gonadotoxic treatment, for later transplantation. The aim of our study was to prove the efficiency of a laparoscopic technique for orthotopic graft after a slow-freezing/thawing protocol, and to evaluate the effect of ovarian cryopreservation and autograft on the primordial follicle survival rate.

Complications associated with cannula insertion techniques used for laparoscopy in standing horses.

Objective: To report our experience and complications associated with different cannula insertion techniques for laparoscopy in standing horses.

Study Design: Retrospective study.

Sample Population: Forty horses that had laparoscopy for diagnostic or surgical purposes.

Better preservation of endothelial function and decreased activation of the fetal renin-angiotensin pathway with the use of pulsatile flow during experimental fetal bypass.

Objective: Pulsatile flow was shown to overcome the progressive rise in peripheral and placental vascular resistances observed during steady-flow bypass, this rise being counteracted by inhibition of nitric oxide synthase. This study quantifies the release of endothelial vasoactive substances during a 60-minute in utero model of fetal bypass.

Methods: Fetuses were randomly allocated into 1 of 2 groups (steady flow, n = 8, or pulsatile flow, n = 13) and subjected to bypass through central cannulation and perfusion with either a centrifugal or pulsatile (125 beats x min(-1)) blood pump.

Effects of various flow types on maternal hemodynamics during fetal bypass: is there nitric oxide release during pulsatile perfusion?

Objective: This study investigates the role of various flow conditions on maternal hemodynamics during fetal cardiopulmonary bypass.

Methods: Normothermic fetal bypass was conducted under pulsatile, or steady flow, for a 60-minute period. Fetal lamb preparations were randomly assigned to 1 of the 3 groups: steady flow (n=7), pulsatile flow (n=7), or pulsatile blocked flow bypass (n=7), where fetuses were perfused with Nomega-nitro-L-arginine after the first 30 minutes of pulsatile flow to assess the potential role of endothelial autacoids.

The hemodynamic effects of hypoxemia in anesthetized pigs: a comparison between right heart catheter and echocardiography.

Unlabelled: During hypoxemia, hypoxic pulmonary vasoconstriction and tachycardia are often observed in association with increases in pulmonary artery pressure and cardiac output. Nevertheless, the hemodynamic consequences of hypoxemia have never been evaluated by echocardiography and simultaneously compared with invasive hemodynamic variables. Fourteen open-chest, anesthetized piglets (weight 29-36 kg) were submitted to progressive hypoxemia and reoxygenation.

Experimental right ventricle to pulmonary artery discontinuity: outcome of polyurethane valved conduits.

Objective: The ideal substitute for the treatment of ventricle-pulmonary artery discontinuity remains a topic of controversy, because of calcifications and degeneration of biologic substitutes leading to subsequent reoperations. Because polyurethane valves used in ventricular assist devices show a satisfactory biocompatibility, the aim of this study was to evaluate a valved conduit composed of a Dacron graft incorporating a trileaflet 25 mm polyurethane valve.

Methods: The conduit was implanted between the right ventricle and the main pulmonary artery in adult sheep, with ligation of the proximal pulmonary artery.

Flow-induced release of endothelium-derived relaxing factor during pulsatile bypass: experimental study in the fetal lamb.

Objective: This study was initiated to test the hypothesis that fetal hemodynamic changes observed under pulsatile flow bypass might be related to the release of endothelium-derived relaxing factor through oscillating shear stress.

Methods: Normothermic bypass was instituted in utero in 21 preterm fetal lambs for a 1-hour period through the right atrium and main pulmonary artery. Ultrasonic flowmeters were positioned around the descending aorta and the umbilical artery.

[Effects of active synchronized prolonged coronary perfusion in the animal].

The efficacy of a system of active diastolic synchronised coronary perfusion was studied during prolonged balloon angioplasty in 8 sheep. In the first part of the study (group 1) including 5 animals, the aim was to study the effects of high and constant flow (48 ml/min) for 90 minutes perfusion on haemolysis, the arterial wall and the perfused myocardium. The second part of the study (group 2), including 3 animals, assessed whether flow adapted to the extent of the vascular bed perfused (24 to 40 ml/min) could protect the myocardium for an interval of 60 minutes.

[Hemodynamics of right circulation in ewes: normal values].

The right cardiac pressure was measured on 24 anesthetized adult ewes (Halothane) with a Swan Ganz catheter. After a review of the catheterization technique, the results (mean +/- standard deviation) in mmHg were: right auricle 17 +/- 5, right ventricle 30 +/- 6 (systolic) and 12 +/- 6 (telediastolic), pulmonary artery 29 +/- 6 (systolic), 13 +/- 6 (diastolic) and 20 +/- 6 (mean), capillary pressure 17 +/- 7. We observed slight variations in the pressure curve morphology compared to those found for man and the pressures were 5-10 mmHg higher than what is observed in man and slightly higher than those observed in dogs.

Pulsatility improves hemodynamics during fetal bypass. Experimental comparative study of pulsatile versus steady flow.

Background: The main advantage of pulsatile flow compared with steady flow during cardiopulmonary bypass is to prevent a rise in systemic vascular resistances. We hypothesized that pulsatile flow could overcome the progressive rise in peripheral and placental vascular resistances observed during fetal bypass and leading to progressive irreversible hypoxemia.

Methods And Results: A study was undertaken in 17 fetal lambs (110 to 140 days of gestation).