Our objective was to examine the hemodynamic effects of a trans-aortic axial flow catheter (Impella CP) in the left ventricle (LV) versus left atrial (LA) to femoral artery bypass using a centrifugal pump (TandemHeart: TH) in a bovine model of acute LV injury. In three male calves, we performed sequential activation of a CP then TH device in each animal. After 60 minutes of left anterior descending artery ligation, a CP was activated at maximal power. The CP was then removed and the TH activated at 5,500 then a maximum of 7,500 rotations per minute (RPM). The CP generated a maximum 3.1 ± 0.2 L/minute (LPM) of flow, whereas the TH at 5,500 and 7,500 RPM generated 3.1 ± 0.4 and 4.4 ± 0.3 LPM. At 3.1 LPM, the CP and TH reduced LV stroke work (LVSW) similarly. The TH reduced stroke volume, whereas the CP did not. The CP reduced end-systolic pressure, whereas the TH did not. At a maximum flow of 4.4 LPM, the TH provided a greater reduction in LVSW than maximal CP activation. This is the first report to compare the hemodynamic effects of trans-aortic LV unloading versus LA-to-femoral artery (FA) bypass.

No abstract

No abstract

ObjectiveResidual scarring after cleft lip repair surgery remains a challenge for both surgeons and patients and novel therapeutics are critically needed. The objective of this preclinical experimental study was to evaluate the impact of the methyl-ester of pro-resolving lipid mediator lipoxin A4 (LXA4-ME) on scarring in a novel rabbit model of cleft lip repair.MethodsA defect of the lip was surgically created and repaired in eight six-week old New Zealand white rabbits to simulate human cleft lip scars. Rabbits were randomly assigned to topical application of PBS (control) or 1 ug of LXA4-ME (treatment). 42 days post surgery all animals were euthanized. Photographs of the cleft lip area defect and histologic specimens were evaluated. Multiple scar assessment scales were used to compare scarring.ResultsAnimals treated with LXA4-ME exhibited lower Visual Scar Assessment scores compared to animals treated with PBS. Treatment with LXA4-ME resulted in a significant reduction of inflammatory cell infiltrate and density of collagen fibers. Control animals showed reduced 2D directional variance (orientation) of collagen fibers compared to animals treated with LXA4-ME demonstrating thicker and more parallel collagen fibers, consistent with scar tissue.ConclusionsThese data suggest that LXA4-ME limits scarring after cleft lip repair and improves wound healing outcomes in rabbits favoring the resolution of inflammation. Further studies are needed to explore the mechanisms that underlie the positive therapeutic impact of LXA4-ME on scarring to set the stage for future human clinical trials of LXA4-ME for scar prevention or treatment after cleft lip repair.