生物瓣衰坏后再次换瓣的体会(附17例报告)

总结 17例生物瓣衰坏患者的临床表现、再手术方法及术后处理。本组 17例患者中 ,男 7例 ,女 10例。生物瓣植入时 ,单纯二尖瓣置换 15例 ,单纯主动脉瓣置换 2例 ,均为牛心包瓣 ,植入体内时间平均 9.8± 1.4年。术中发现 17枚生物瓣均有不同程度的纤维化或钙化 ,拆除后全部置换机械瓣。术后早期无死亡 ,晚期死亡 2例。生物瓣衰坏随植入时间延长逐渐加重 ,心肌保护采用持续温血停搏液灌注效果好 ,预充抑肽酶能明显减少术后出血 ,心功能差者术后要加强心肺功能支持     

Endocardite infectieuse sur TAVI compliqué d’abcès et pseudo-anévrysme : apport du scanner cardiaque synchronisé à l’ECG

A 80-year-old man was admitted to catheterization room for an acute infero-lateral ST-elevation myocardial infarction (STEMI). Coronary angiography showed a thrombotic occlusion of the second left marginal branch, and normal other coronary arteries. The thrombo-embolic mechanism of the STEMI, and the infectious context in this patient who had had a transcatheter aortic valve implantation (TAVI) two months earlier, led us to suspect a bioprosthesis endocarditis. It was confirmed by transthoracic and transoesophageal echocardiography, which showed an aortic-mitral curtain abscess and aortic bioprosthesis vegetations, associated to Enterococcus faecalis bacteriemia. In order to specify the diagnosis, an ECG-gated multidetector CT angiography (MDCTA) had been performed. Additionally to echocardiographic findings, MDCTA showed a pseudo-aneurysm, sized 20 to 22 mm, beginning from the outflow tract of the left ventricle to end on the antero-lateral face of the aorta. The patient was referred for emergency aortic bioprosthesis removal and replacement. Through this case, MDCTA showed its importance for the diagnosis and the prognostic evaluation of cardiac prosthesis endocarditis. MDCTA provided additional informations that echocardiography could not detect, because of artifacts caused by the prosthetic material and calcifications, frequent in elderly patients with comorbidities.     

Contemporary results with the biosynthetic glutaraldehyde denatured ovine collagen graft (Omniflow II) in femoropopliteal position

ObjectiveThe objective of this study was to analyze the outcome of a contemporary series of femoropopliteal bypass operations with the glutaraldehyde denatured polyester mesh-reinforced ovine collagen prosthesis (OCP; Omniflow II [LeMaitre Vascular, Inc, Burlington, Mass]). The experience of two tertiary centers regarding long-term graft function, secondary reinterventions, and biodegeneration of the OCP prosthesis is presented.MethodsBetween January 2006 and January 2014, a series of 205 consecutive operations with the OCP in the femoropopliteal position (54 above knee and 151 below knee) were performed in 194 patients in 202 limbs for disabling claudication (72), chronic critical ischemia (105), acute ischemia (18), popliteal artery aneurysm (4), degeneration of a venous or prosthetic graft (5), and infection of a synthetic bypass graft (1). Grafts were observed with duplex ultrasound scan supplemented by additional angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Retrospective analysis of graft patency, limb salvage, and diagnosis of aneurysmal graft degeneration was performed.ResultsThe 30-day mortality was 3.9%. Early thrombotic bypass occlusion occurred in 8.2% of cases. Four early graft infections could be successfully managed by local treatment with graft preservation. After a mean (median) follow-up of 56 (55) months (range, 1-135 months), primary patency, primary assisted patency, secondary patency, and limb salvage were 71%, 78%, 78%, and 91% for above-knee bypass and 40%, 50%, 63%, and 87% for below-knee bypass at 5 years. Biodegeneration in the form of graft aneurysm or graft stenosis was detected in 26 grafts (12.6%), resulting in secondary open or endovascular procedures in 16 cases.ConclusionsThe OCP provides satisfactory medium- and long-term patency and limb salvage in the femoropopliteal position. Aneurysmal degeneration or graft stenosis may develop over time, demanding lifelong duplex ultrasound surveillance and secondary intervention if needed. Its possible infection-resistant behavior in a contaminated field combined with an acceptable graft patency and limb salvage justifies the use of this graft in the absence of autologous vein.     

生物瓣膜:多年轻是年轻

A favorite question in Doctors and Patients is, ＂What valve would you use for patient ？ And what kind of valve suits me better in my life ？ Would you use a mechanical prosthesis, a bioprosthesis .9 Numerous studies show that there are many safe choices and that the operation has to be individualized to the patient.     

复合鞣制方法处理生物瓣膜生物材料性能评估

目的：对复合鞣制方法处理的生物材料性能及生物瓣膜临床应用效果进行评估。方法：对比用戊二醛、阳离子油、三氧化二铬及甘油等复合鞣制的生物材料和单纯戊二醛鞣制生物材料的组织钙含量。对生物材料进行组织学、超微结构和机械抗张强度测试，用傅立叶红外光谱仪测定羧基含量。生物瓣膜经体外模拟疲劳寿命实验台加速检测。结果：复合鞣制生物材料组织钙含量低，组织胶原纤维结构排列致密、整齐，细胞结构完整，收缩温度在86～90℃时生物材料最柔软，抗张强度19．9～25．9N／mm^2，延伸率43．4％～46．0％；红外光谱图显示羧基(COOH^-1)峰明显降低；体外模拟加速疲劳实验台测试，猪主动脉瓣膜能经受3．892亿次循环，牛心包瓣膜为3．888亿次，从受力疲劳方面看将能经受住大约10年的寿命。结论：用复合鞣制方法处理生物材料，可提高生物瓣膜的柔软性和强度，对生物瓣膜的防钙化起重要作用。     

冷冻速率对猪主动脉冷冻保存效果的影响

目的比较不同冷冻速率对大口径猪动脉功能及内皮的影响.方法 16头乳猪切取胸主动脉,每根主动脉分3段,作为对照、-1℃/min冷冻和-5℃/min冷冻处理.分别测定内皮细胞死亡率和血管活性药物引起的收缩、舒张程度.结果 -5℃/min冷冻组内皮细胞死亡率明显高于-1℃/min冷冻组和对照组,P＜0.01.冷冻组由去甲肾上腺素引起的收缩张力值明显低于未冷冻对照组P＜0.01.-5℃/min组明显低于-1℃/min组,P＜0.01.冷冻组由乙酰胆碱引起的张力下降绝对值与对照组差异无显著性,P＞0.05;舒张程度与对照组有明显差异,P＜0.01.-5℃/min组舒张程度明显低于-1℃/min组,P＜0.01.内皮细胞死亡率与乙酰胆碱舒张作用呈负相关,P＜0.05.结论冷冻对猪主动脉的结构和功能造成损伤.慢速冷冻对内皮细胞破坏小,对血管平滑肌的收缩和内皮依赖性舒张的损害小.     

The susceptibility of bioprosthetic heart valve leaflets to oxidation

The clinical use of bioprosthetic heart valves (BHV) is limited due to device failure caused by structural degeneration of BHV leaflets. In this study we investigated the hypothesis that oxidative stress contributes to this process. Fifteen clinical BHV that had been removed for device failure were analyzed for oxidized amino acids using mass spectrometry. Significantly increased levels of ortho-tyrosine, meta-tyrosine and dityrosine were present in clinical BHV explants as compared to the non-implanted BHV material glutaraldehyde treated bovine pericardium (BP). BP was exposed in vitro to oxidizing conditions (FeSO₄/H₂O₂) to assess the effects of oxidation on structural degeneration. Exposure to oxidizing conditions resulted in significant collagen deterioration, loss of glutaraldehyde cross-links, and increased susceptibility to collagenase degradation. BP modified through covalent attachment of the oxidant scavenger 3-(4-hydroxy-3,5-di-tert-butylphenyl) propyl amine (DBP) was resistant to all of the monitored parameters of structural damage induced by oxidation. These results indicate that oxidative stress, particularly via hydroxyl radical and tyrosyl radical mediated pathways, may be involved in the structural degeneration of BHV, and that this mechanism may be attenuated through local delivery of antioxidants such as DBP.