Panzer Joseph, De Somer Filip, Segers Patrick, De Wolf Daniel, Bove Thierry
Experimental Research Laboratory of Cardiac Surgery and Circulatory Physiology, Faculty of Medical Sciences, Ghent University, Ghent, Belgium.
Department of Pediatric Cardiology, University Hospital Ghent, Ghent, Belgium.
Eur J Cardiothorac Surg. 2020 Dec 1;58(6):1206-1215. doi: 10.1093/ejcts/ezaa241.
The aim of this study was to investigate the effect of short- versus long-segment aortic stiffness and stenosis on ventriculo-arterial interaction in a porcine model of coarctation repair.
Short-long aortic stiffness was created by transection/suture [coarctation (CoA) suture, n = 6] and stenting (stent, n = 5) of the proximal descending aorta. Short-long aortic stenosis was achieved by wrapping a prosthetic graft around the aorta to 1/3-circumference reduction, over a segment length of 1 cm (CoA suture stenosis, n = 5) and 4.5 cm (stent stenosis, n = 6). After 3 months, aortic pressure-flow haemodynamics, aortic distensibility by intravascular ultrasound and left ventricular performance by pressure-volume loops were compared to a Sham group (n = 5) at baseline and during dobutamine administration.
The aortic impedance increased with 30.3 (12.6%) and 41.3 (20.9%) (P < 0.001) in CoA stenosis and stent stenosis during inotropic response. Impaired haemodynamic aortic compliance was associated with lower aortic distensibility by intravascular ultrasound, specifically in long-segment stenosis. The ventriculo-arterial coupling was disturbed in both groups with stenosis, with blunted contractile response [Sham 140.3 (19.8%), CoA suture 101.3 (14.5%), CoA suture stenosis 75.0 (8.4%), stent 115.5 (12.7%), stent stenosis 55.1 (14.6%), P < 0.001] and increased myocardial stiffness during dobutamine in the long-segment aortic stenosis group [Sham -26.0 (12.9%), CoA suture -27.5 (15.9%), CoA stenosis -9.5 (8.6%), stent -23.4 (4.8%), stent stenosis 19.9 (23.1%), P < 0.001].
This animal study on the sequelae of coarctation repair demonstrated that aortic stiffness had little effect on aortic pressure-flow characteristics in the absence of stenosis. However, the negative chronic effect of stenosis on aortic haemodynamics-especially a longer segment-leads to the rapid impairment of ventriculo-arterial interaction, which is accentuated by inotropy. Therefore, therapeutical management needs to focus on improving aortic remodelling after coarctation repair, preferably by minimizing residual stenosis, even at the cost of inducing aortic stiffness.
本研究旨在探讨在猪主动脉缩窄修复模型中，短节段与长节段主动脉僵硬度和狭窄对心室 - 动脉相互作用的影响。
通过横断/缝合（主动脉缩窄[CoA]缝合，n = 6）和近端降主动脉支架置入（支架，n = 5）来制造短 - 长主动脉僵硬度。通过用人工血管围绕主动脉缠绕使其周长减少1/3，在1 cm（CoA缝合狭窄，n = 5）和4.5 cm（支架狭窄，n = 6）的节段长度上实现短 - 长主动脉狭窄。3个月后，将主动脉压力 - 血流动力学、血管内超声测量的主动脉扩张性以及压力 - 容积环测量的左心室功能与假手术组（n = 5）在基线和多巴酚丁胺给药期间进行比较。
在变力反应期间，CoA狭窄和支架狭窄组的主动脉阻抗分别增加了30.3（12.6%）和41.3（20.9%）（P < 0.001）。血管内超声显示，血流动力学主动脉顺应性受损与主动脉扩张性降低相关，特别是在长节段狭窄中。两组狭窄患者的心室 - 动脉耦合均受到干扰，收缩反应减弱[假手术组140.3（19.8%），CoA缝合组101.3（14.5%），CoA缝合狭窄组75.0（8.4%），支架组115.5（12.7%），支架狭窄组55.1（14.6%），P < 0.001]，并且在长节段主动脉狭窄组中，多巴酚丁胺给药期间心肌僵硬度增加[假手术组 - 26.0（12.9%），CoA缝合组 - 27.5（15.9%），CoA狭窄组 - 9.5（8.6%），支架组 - 23.4（4.8%），支架狭窄组19.9（23.1%），P < 0.001]。
这项关于主动脉缩窄修复后遗症的动物研究表明，在无狭窄的情况下，主动脉僵硬度对主动脉压力 - 血流特性影响不大。然而，狭窄对主动脉血流动力学的负面慢性影响——尤其是较长节段——会导致心室 - 动脉相互作用迅速受损，变力作用会加剧这种损害。因此，治疗管理需要专注于改善主动脉缩窄修复后的主动脉重塑，最好通过尽量减少残余狭窄，即使以诱导主动脉僵硬度为代价。
