人工瓣膜功能障碍的外科治疗

目的 总结41例人工心脏瓣膜功能障碍(PHVD)的临床特点、外科治疗方法 及围术期处理经验.方法 手术均在全麻低温体外循环下进行;1例采取股动脉插管左侧开胸,40例均经原切口,主动脉、上下腔静脉插管建立体外循环.38例行瓣膜置换术,使用机械瓣35枚(二尖瓣位23枚,主动脉瓣位11枚,三尖瓣位1枚),生物瓣6枚(二尖瓣位3枚、主动脉瓣位2枚、三尖瓣位1枚);2例行瓣膜角度矫正术;1例行异物清除术.急诊手术13例,择期手术28例.结果 全组气管插管5.1～243.0 h,平均63.3 h,中位时间15.3 h;气管切开5例.全组死亡6例,病死率14.6%,均发生于急诊手术后,死因为低心排血量综合征3例、多器官衰竭2例及恶性心律失常1例.并发症包括感染性心内膜炎、顽固性呃逆及切口感染各1例.结论 对急性PHVD,无论是生物瓣或机械瓣,均应立即进行急诊手术.对慢性PHVD亦应强调及早再次手术.     

脱细胞牛心包种植人血管混合细胞构建组织工程心脏瓣膜

目的 探讨在脱细胞牛心包上种植人血管混合细胞构建组织工程心脏瓣膜的方法与效果.方法 将体外培养的人血管混合细胞种植在脱细胞牛心包材料上,观察种子细胞形态学和免疫组织化学变化和牛心包超微结构变化,并测定内皮细胞分泌t-PA和PAI-1的活性.结果 种子细胞全层覆盖脱细胞牛心包表面,并浸润至组织内部生长;牛心包表面为扁平、片状、分层的细胞覆盖,细胞表面有少量绒毛和纤细的纤维结构.免疫组化显示内皮细胞Ⅷ因子、平滑肌细胞α-肌动蛋白、成纤细胞Fibronectin相关抗原呈阳性表达;种子细胞能分泌纤溶活性物质t-PA和PAI-1.结论 人血管混合细胞种植后附着满意,与脱细胞牛心包生物相容性好,生长状况好,并具有内皮功能.     

微创心脏瓣膜替换术73例报告

目的介绍一种微创心脏瓣膜替换术的新方法。方法于１９９７年３月至１９９８年４月为７３例瓣膜患者经右侧腋下胸部小切口,皮切口平均长度为（８５±０９）ｃｍ,进行了心脏瓣膜替换手术。结果平均循环阻断时间（８８６±３３８）分钟,平均转机（１１７０±４５９）分钟,有５例患者未阻断升主动脉,室颤下完成了二尖瓣替换术。术后气管插管时间（９６±３６）小时,平均胸液引流量（２６４５±１８４３）ｍｌ。１例患者院内死于脑出血。随诊中２例患者出现感染性心内膜炎,其中１例患者死亡。其他随诊良好。结论微创心脏瓣膜替换术安全可靠,可减少手术对患者的影响,利于患者恢复,同时为换瓣手术技术的改进提供了新经验。     

Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

Introduction

In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench.

Objective

To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream.

Methods

To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements.

Results

It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found.

Conclusions

Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.     

心脏机械瓣膜置换术后妊娠妇女低强度华法林抗凝治疗56例

目的 探讨心脏机械瓣膜置换术后妊娠妇女低强度抗凝治疗的方法,以及抗凝药物对孕妇和胎儿的影响.方法 随访56例心脏机械瓣膜置换术后妇女妊娠、分娩期抗凝治疗情况.结果 56例(61例次)妊娠全程均口服华法林行抗凝治疗,42例用国产华法林(3.02±0.85)mg/日,14例用进口华法林(2.84±0.57)mg/日,国际标准比值(INR)均值为1. 67±0.58.所有孕妇均无严重出血及栓塞等并发症发生,仅11例次有一般性出血现象.本组足月妊娠47例,早产7例,自然流产6例,死产(畸胎)1例;低体重儿6例.新生儿均无畸形发生.结论 心脏机械瓣膜置换术后妇女妊娠全程服用较小剂量华法林(＜5 mg/日)行低强度抗凝治疗(INR=1.5～2.0)对孕妇安全、方便,且胎儿并发症发生率较低.

Abstract：

Objective To evaluate the method of low-intensity anticoagulation therapy in the pregnant women who had received mechanical heart valve replacemant, and the effects of warfarin on the pregnant women and their fetus. Methods This retrospective study involved 56 pregnant women( 61 pregnancies)who had received mechanical heart valve replacement.Their pregnant status, delivery, and anticoagulation therapy were observed and followed-up between May 1986 and November 2009 at West China Hospital of Sichuan University. Results All patients took oral anticoagulant (warfarin) throughout pregnancy. The dose of domestic warfarin was ( 3.02 ± 0.85 ) mg/d ( in 42 cases), and the dose of imported warfarin was (2.84 ± 0.57 )mg/d (in 14 cases). The mean INR value of 401 samples from patients was 1.67 ±0.58. No thromboembolism or major hemorrhagic complications occurred. Minor bleeding occurred in 11 pregnancies. Forty-seven patients had term delivery, 7 had premature birth, 6 had spontaneous abortion, and 1 had intrauterine fetal death. Six newborns were born with low birth weight (2.3 ± 0. 5 ) kg, and no abnormal fetus was observed. Conclusion The low-intensity anticoagulation therapy with warfarin (at a dose of less than 5 mg/d) and a INR target of 1.5 to 2.0 was safe and convenient for the pregnant women,who had received mechanical heart valve replacement. The abnormalities rate of fetus was low.     

二尖瓣狭窄分离术后晚期复发病人瓣膜置换术278例分析

目的　探讨风湿性二尖瓣狭窄闭式扩张分离术后晚期复发瓣膜的病理改变 ,及其再次手术方式的选择。方法　 1978年 12月至 2 0 0 1年 12月共收治风湿性二尖瓣狭窄闭式扩张分离术后晚期复发性瓣膜病 2 78例。二尖瓣复发性病变均以狭窄为主合并不同程度的关闭不全。其中合并三尖瓣功能性关闭不全 12 7例 (4 5 7% ) ,合并复发性主动脉瓣病变 33例 (11 9% ) ;二尖瓣与主动脉瓣双瓣膜病变合并三尖瓣病变 6 1例 (2 1 9% )。二尖瓣复发性病变的病理特点主要表现为 (1)交界硬化融合型 4 6例 (16 5 % ) ;(2 )后瓣钙化卷缩型 18例 (6 5 % ) ;(3)交界钙化融合型 177例 (6 3 7% ) ;(4 )瓣膜与瓣下结构钙化型 37例(13 3% )。所有病人均行二尖瓣置换术 ,其中二尖瓣与主动脉瓣双瓣置换术 33例 ;三尖瓣功能性关闭不全作改良DeVega成形术 137例、Kay二瓣化环缩术加用成形环固定 5 1例。 结果　早期死亡 19例(6 8% ) ,主要死因为心力衰竭与多脏器功能衰竭。长期生存 2 5 9例 ,随访率 95 7% ,随访 6个月～ 2 2年 ,累计随访时间 116 2 2年。晚期死亡 15例 ,累计生存率 5、10、15年分别为 85 5 %、71 2 %、6 5 1%。抗凝过量出血的发生率为 1 11%病人·年。结论　风湿性二尖瓣狭窄闭式扩张术后晚期瓣膜复发性病变 ,再次     

同种带瓣大动脉片在肺血少型复杂先天性心脏病手术中的应用

目的　评价同种带瓣大动脉片在手术矫治肺血少型复杂先天性心脏病(先心病)中应用的临床效果。方法　420例复杂先心病病人(儿)手术中应用了同种带瓣大动脉片,其中同种主动脉单瓣补片234例,肺动脉单瓣补片186例。年龄5个月～21岁,平均4.6岁。体重5.5～52.0kg,平均17.5kg。随访3个月～12.3年,平均(27.8±10.3)个月。结果　全组手术死亡率4.5%(19/420例);术后机械辅助呼吸8～192h,平均(48.67±42.50)h;术后住院7～46d,平均(12±9)d。无晚期死亡及并发症发生。结论　对于相当一部分肺动脉发育差、以往难以手术根治的病人(儿),术中应用同种带瓣大动脉片行右室流出道跨环补片,可取得满意手术疗效。     

A Swine model for long-term evaluation of prosthetic heart valves

BACKGROUND: The objective of this study was to develop a porcine model of mitral valve replacement (MVR) for long-term evaluation of prosthetic heart valves. METHODS: Sixteen 25-kg male Bama miniature pigs underwent MVR using St Jude Medical valve (21 mm). Each animal was allocated to an anticoagulation protocol after surgery (group I, s.c. heparin injection and warfarin (n = 8); group II, s.c. low-molecular-weight heparin and warfarin (n = 8)) and was followed for up to 20 weeks. Terminal studies were carried out on all animals having survived for more than 140 days or died. RESULTS: Fourteen animals survived for more than 1 month without signs of heart failure. One of group I animals died from haemorrhagic (haemopericardium) complications on the 9th postoperative day, and another animal of group I died on the 18th postoperative day because of valve thrombosis. CONCLUSIONS: Compared with other species, humans and pigs show remarkable anatomical and physiological similarities. This model is promising for long-term preclinical evaluation of prosthetic heart valves and evaluation of postoperative anticoagulant agents.     

Introduction of a flexible polymeric heart valve prosthesis with special design for aortic position

Objective: Current prosthetic heart valves necessitate permanent anticoagulation or have limited durability and impaired hemodynamic performance compared to natural valves. Recently a polymeric valve prostheses with special design for mitral position demonstrated excellent in vitro and in vivo results with improved durability and no need for permanent anticoagulation. In this study, a respective flexible polymeric aortic valve is presented and in vitro and in vivo results are reported. Methods: The aortic prosthesis (ADIAM^® lifescience AG, Erkelenz, Germany) is entirely made of polycarbonaturethane. The tri-leaflet flexible prosthesis mimicks the natural aortic valve and has a diminished pressure loss and reduced stress and strain peaks at the commissures. The valve underwent long-term in vitro testing and in vivo-testing in a growing calve animal model (20 weeks, 7 aortic valves) and was compared to two different commercial bioprostheses. Results: The polymeric aortic heart valve substitute demonstrated excellent in vitro and in vivo hemodynamics. Five/seven animals with aortic PCU-prostheses had an excellent clinical long-term course. The explanted valves showed a variable degree of calcification. Two of the seven animals died at 27 and 77 days due to pannus overgrowth causing severe LVOTO without degeneration of the valve itself. Both animals with commercial bioprostheses had to be sacrificed because of congestive heart failure related to structural degeneration of the bioprosthesis after 10 and 30 days of implantation. There was no increased thrombogenity of the PCU valves compared to bioprostheses. Conclusion: The new flexible polymeric aortic valve prosthesis is superior to current bioprostheses in animal testing.     

The cardiovascular tissue-reactor: a novel device for the engineering of heart valves

The shortage of human donor valves and disadvantages of current mechanical and xenogenic valve grafts cause a growing demand for biologically engineered valves. We developed a bioreactor for in vitro transformation of porcine semilunar heart valves into human valves. The reactor design was optimized in order to achieve a complete removal of porcine cells by trypsinization and cellularization of the remaining matrix with human vascular cells. The physical parameters of the reactor were characterized. Based on these data, decellularization and cellularization protocols were developed and the successful application of protocols was investigated by immunohistochemistry. The resulting reactor consisted of two connectable and perfuseable modules. Heart valve structures of varying sizes could be mounted into the reactor and could be completely depopulated within 4 days by a sequence of enzymatic and mechanical treatments applied simultaneously to the valves. Complete cellularization with human cells could be achieved after optimizing the seeding design, density, and time.