经液氮保存有活性同种带支架瓣膜的实验研究

目的 检测经液氮保存的人同种带支架瓣膜的细胞活性和流体力学性能.方法 制作同种带支架瓣膜经液氮保存3个月后,利用流式细胞仪技术定量检测瓣叶细胞活性(实验组,n=6),采集新鲜同种瓣膜作为对照(对照组,n=6).利用国产脉动流实验装置,分别测试实验组21#、23#、25#同种带支架瓣膜的流体力学性能,测试各流量下的跨瓣压差、有效瓣口面积和回流百分比;并使用相应型号的国产Perfect牛心包生物瓣膜进行对比研究.结果 实验组内皮细胞死亡率与对照组比较差异无统计学意义(10.24%±1.71% vs.9.09%±2.72%,P=0.441);实验组平滑肌细胞死亡率与对照组比较差异无统计学意义(8.76%±1.82% vs.7.84%±0.59%,P=0.178);实验组总细胞死亡率与对照组比较差异无统计学意义(8.79%±1.44% vs.7.40%±0.49%,P=0.072).两种21#、23#、25#人工生物瓣膜的跨瓣压差对流量具有非常大的依赖性,随着流量的增大而增大.同种带支架瓣膜的跨瓣压差较Perfect牛心包生物瓣膜的大.两种各型号瓣膜的回流百分比均随测试流量的增大而略有减小,同样,同种带支架瓣膜的回流百分比较Perfect牛心包生物瓣膜的大.两种各型号瓣膜的有效瓣口面积均有随流量增加而增大的趋势,同种带支架瓣膜的有效瓣口面积较Perfect牛心包生物瓣膜的略小.结论 经液氮保存同种带支架瓣膜的细胞活性保存良好,流体力学性能较满意.     

同种带瓣心外管道的临床应用

目的　探讨同种带瓣主动脉和肺动脉心外管道治疗复杂先天性心脏病的临床效果。　方法　应用深低温保存同种带瓣主动脉或肺动脉心外管道重建右心室流出道治疗复杂先天性心脏病 31例 ,其中 ,右心室双出口 6例 ,矫正型大动脉转位 2 1例 ,完全型大动脉转位 2例 ,三尖瓣闭锁 1例 ,感染性心内膜炎合并主动脉瓣关闭不全 1例。应用同种主动脉 2 7例 ,同种肺动脉 4例。　结果　术后同种管道吻合口通畅 ,无压差、无扭曲和受压 ,同种瓣膜活动良好。　结论　同种带瓣主动脉和肺动脉心外管道具有生物活性和完整的瓣膜功能 ,可从解剖学和血流动力学上矫正心脏畸形     

新型改良单层缝合无支架猪主动脉瓣的初步研究及体外测试

目的设计新型无支架猪主动脉瓣,改进其植入方法,并进行体外流体力学测试,评价其性能及可行性。方法6枚无支架猪主动脉瓣,根据植入缝合方法不同分为两组,单层缝合组：采用本实验中设计的新型改良单层缝合无支架猪主动脉瓣;双层缝合组：采用我科此前自行研制的新型无支架猪主动脉瓣;每组取直径为23mm、25mm和27mm瓣膜各1枚。术后用体外脉动流测试仪按照ISO5840的评估标准,分别检测两组瓣膜在心排血量（CO）为2．0L／min、3．5L／min、5．0L／min和7．0L／min的平均跨瓣压差、有效瓣口面积（EOA）和反流百分比等体外流体力学指标。结果单层缝合组瓣膜平均植入时间50min,双层缝合组70min。流体动力学测试结果显示：单层缝合组23mm瓣膜和27mm瓣膜在CO为5．0L/min时跨瓣压差均小于双层缝合组（13．51±0．51mm Hg vs．14．44±0．99mm Hg;7．36±0．19mm Hg vs．7．53=0．28mm lHg;P〈0．01）,EOA大于双层缝合组（1．87±0．06cm^2 vs．1．76±0．08cm^2,2．26±0．07cm^2 vs．2．16±0．05cm^2;P〈0．01）;其余测试条件下两组指标的测试结果差异无统计学意义。结论新型改良单层缝合尤支架猪主动脉瓣具有天然的结构,表现出良好的血流动力学特性,改进后的单层缝合植入方法,缩短了植入时间,体外脉动流测试显示其平均跨瓣压差、EOA、反流百分比等体外流体力学数据与双层缝合法比较差异无统计学意义。该实验为今后的动物实验和临床试验打下了基础。     

带瓣牛颈静脉作为右室肺动脉连接管道的研究

许多心脏疾病，如法洛四联症、肺动脉闭锁、右室双出口等以及主动脉病变行Ross手术者，均需重建右室肺动脉连接，常用的材料有自体心包、异种材料、同种异体主动脉带瓣管道、人工材料如Gore-tex片、人工合成的带瓣管道。这些材料均存在局限性，Gore-tex片一般不能重建瓣膜结构；自体心包构造带瓣的结构，效果不理想；由于右心系统压力低，血流速度慢，     

同种瓣内皮细胞再孵化的进展

自 195 6年首次使用新鲜的同种瓣治疗主动脉瓣关闭不全 ,至 1975年 ,因同种主动脉瓣置换的效果较差 ,瓣膜损坏率明显高于异种生物瓣 ,几近废弃。同年 ,Ｏ’Ｂｒｉｅｎ等创立了抗生素灭菌、控制降温速率、液氮深低温保存法 ,使瓣膜组织内成纤维细胞存活 ,瓣膜性能有较大的提高 ,同种瓣再次被广泛地应用于心脏外科。同种瓣的优点同种瓣有以下优点 :( 1)自然构形 ,最适宜的流体力学功能和中央无阻碍血流 ,故具有最好的血液动力学效应 ,跨瓣压差低 ,如同生理瓣膜。 ( 2 )无声响。 ( 3)退化慢 ,瓣叶较少发生钙化。 ( 4)血栓形成和栓塞发生率很低 …     

猪非体外循环下经皮肺动脉瓣膜置入术

目的 探讨肺动脉自扩张支架瓣膜的制备以及非体外循环下经皮肺动脉瓣膜置入方法.方法 将修剪后的牛颈静脉带瓣管道缝制到自扩张镍钛支架上,制成肺动脉自扩张支架瓣膜,并置于人工心脏瓣膜脉动流测试仪中检测通过后备用.借助24F支架输送鞘,经髂外静脉途径置入到8头实验猪的肺动脉瓣位置,行超声心动图和数字减影血管造影(DSA)等检测置入瓣膜功能后解剖.结果 肺动脉自扩张支架瓣膜内径(21.9±1.6) mm,外径(24.6±1.5) mm,长(27.9±4.3) mm,有效开瓣面积( 1.83±0.2)cm2.8例中7例置入成功,1例失败.置入后瓣膜两端的峰值跨瓣压差导管法检测为(7.9 ±3.3)mm Hg(1 mm Hg =0.133 kPa),彩色多普勒心脏超声检测为(9.3±4.1)mmHg.心脏DSA显示所有支架瓣膜无移位、反流或瓣周漏.二维心脏超声显示7例瓣膜启闭完全,瓣叶活动良好,彩色多普勒心脏超声测得其中2例轻度反流.心脏解剖证实支架瓣膜位于肺动脉瓣环处,原肺动脉瓣膜被支架挤贴在动脉壁上.结论 自扩张肺动脉支架瓣膜能在非体外循环下借助导管经皮置入到肺动脉瓣处,术后短期功能良好,提示自扩张支架瓣膜及经皮肺动脉瓣膜置入术具有可行性和临床应用前景.     

新型高分子材料介入肺动脉瓣膜的动物实验研究——中期随访结果CSCD

目的 评价自主研制的新型高分子材料介入肺动脉瓣膜动物体内原位置换后的中期实验效果.方法 选用超微孔膨体聚四氟乙烯（ePTFE）材料制作成三叶球囊扩张型介入瓣膜,选用牛心包介入瓣膜作对照.雄性羊12只,体质量（22.1±2.3）kg,10只置入高分子材料瓣膜（PPHV）,2只置入对照瓣.右侧开胸经导管经右心室心尖途径原位置换肺动脉瓣.术后随访12周,通过超声心动图、胸部CT、心血管造影、尸检等对介入瓣膜进行中期评价.结果 两枚PPHV未成功原位移植,其余10只羊手术获得成功.术后1只置入PPHV的羊因肺部感染死亡,其余9只存活到随访终点.超声心动图提示,术后12周时PPHV均无明显反流,瓣膜峰值跨瓣压差16～38 mmHg（1 mmHg=0.133 kPa）,平均（28.2±8.0）mmHg;牛心包瓣峰值跨瓣压差分别为16 mmHg和21 mmHg.术后12周胸部CT、心血管造影提示所有人工心脏瓣膜均正常工作,支架无移位或变形.尸检结果提示：术后12周时ePTFE瓣叶无降解或损伤,大部分保持光滑,无血栓、钙化,但密封套囊、瓣叶流出面根部、瓣窦底部、3个瓣叶交界处有血管翳增生.结论 超微孔ePTFE介入肺动脉瓣膜动物体内原位置换后中期效果良好,PPHV有良好的抗组织粘附性能,有良好的抗降解、抗血栓、抗钙化和生物力学性能,血流动力学参数与牛心包对照瓣相当.局部血管翳增生可能通过优化瓣膜设计来改善.     

无支架带腱索支持生物心脏瓣膜的研究

为研制无支架带腱索支持生物心脏瓣膜并对其血流动力学及抗钙化性能进行评价,试验选用年幼绵羊9只,新鲜牛心包经98％甘油鞣制后,缝制成21mm无支架生物瓣,在常温体外循环下行绵羊二尖瓣替换。术后不抗凝,2～8个月后择期行心导管,左室造影及病理检查。结果表明:全组无血栓、栓塞或感染。8例于术后168.4±55.3天,经血流动力学检测:平均跨瓣压差0.76±0.20kPa,有效瓣口面积1.9±0.75cm~2,心脏指数104.1±38.7ml/kg/min;瓣膜无关闭不全或轻度关闭不全者各3例,中度关闭不全者2例。瓣膜病理检查:仅2例有中度钙化,6例轻度钙化。电镜扫描示7例有内皮细胞覆盖生长。1例于术后220天死于心衰,为瓣膜交界处缝线松脱,产生关闭不全所致;其瓣膜表面光泽、柔软,无任何增厚或钙化灶。提示该无支架带腱索支持生物心脏瓣膜的血流动力学及抗钙化性能均满意。     

同种带瓣主动脉用于矫正型大动脉转位合并肺动脉狭窄手术治疗

目的将同种带瓣主动脉经过适宜处理后，用以治疗１８例合并肺动脉狭窄的矫正型大动脉转位（ＣＴＧＡ）患者，其中内脏正位（ＳＬＬ）型１４例，内脏反位（ＩＤＤ）型４例，均合并室间隔缺损（ＶＳＤ）。方法手术缝闭肺动脉瓣口，修复ＶＳＤ，用经过冷冻处理的同种带瓣主动脉管道连接功能右心室和肺动脉。结果术后测压：右心室收缩压为３．３～６．４ｋＰａ（２５～４８ｍｍＨｇ），右心室－肺动脉压差０．６６～３．０ｋＰａ（５～２２ｍｍＨｇ），右心室／左心室压比值０．３～０．６。结论采用同种带瓣主动脉能使患者术后血流动力学指标更接近于人体正常生理状态。     

同种生物心脏组织工程瓣体外构建的初步研究

目的　在生物瓣支架上种植并静态培养自体内皮细胞 (ECs) ,形成完整的内皮细胞单层 ,为下一步脉动流培养并最终体外构建同种生物组织工程瓣 (TEHV)提供材料基础。方法　生物瓣支架选择经液氮保存的成人主动脉带瓣管道 ,用 0 1 %SDS脱去表面的ECs ;成人骨髓间充质干细胞 (MSCs)体外定向诱导分化的ECs作为种子细胞 ,高密度 (>1 0 5cell/cm2 )种植于瓣膜支架上静态培养 2 0d ,扫描电镜观察、摄片 ,以确定再内皮化程度。结果　同种生物瓣支架表面的ECs完全脱去 ,而细胞外基质成分保存良好 ;MSCs体外诱导分化的ECs与生物瓣支架复合体静态培养第 7、1 4和 2 0d ,再内皮化程度分别为 73%、85 %和 92 %。结论　静态培养条件下构建的TEHV基本上实现了体外再内皮化的预期目标。     

Left ventricular mass reduction after aortic valve replacement: homografts, stentless and stented valves.

BACKGROUND: We studied the effect of four different types of prosthetic aortic valves on time course and extent of regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis. METHODS: Four groups of 10 patients each were randomly assigned to receive: (1) aortic homograft preserved in antibiotic solution at 4 degrees C, (2) Toronto stentless porcine valve, (3) Medtronic Freestyle stentless valve, or (4) Medtronic Intact aortic valve. The left ventricular mass index, effective orifice area index, and peak and mean transaortic gradients were measured by Doppler echocardiography before the operation and 8 months postoperatively. RESULTS: The hemodynamic performance indices were much better for the homograft and stentless valves than for the stented one. The absolute left ventricular mass index reduction was greater in the homograft group compared with the Intact (p = 0.0004) and Toronto (p = 0.007) groups. The extent of percent left ventricular mass index reduction was greater only in the homograft group versus Intact group (p = 0.005). The multilinear regression analysis showed that the only predictors of a larger percentage of left ventricular mass index reduction were the homograft type, a higher valve size index, and a higher preoperative left ventricular mass index. CONCLUSIONS: When a stentless or homograft aortic valve was used instead of a stented valve to replace a stenotic aortic valve there was more complete or at least faster regression of left ventricular hypertrophy. The hemodynamic performance of stentless porcine valves was similar to that of aortic homografts, nevertheless the aortic homografts preserved in antibiotic solution offered a faster regression of left ventricular hypertrophy during the same period of time.     

Hydrodynamic function of the second-generation mitroflow pericardial bioprosthesis

BACKGROUND: The hydrodynamic function of the smaller size Mitroflow Synergy stented pericardial bioprostheses has been studied in an in vitro fresh tissue aortic root model and compared with previous studies of free-sewn bioprostheses. METHODS: Three valves of each of the sizes 19, 21, and 23 mm were sutured into fresh tissue aortic roots and tested in a pulsatile flow simulator using two different ventricular input impedance conditions. A high-speed camera was used to study the leaflet opening and closing configurations. Mean pressure difference as a function of root mean square forward flow, effective orifice area, regurgitant volumes, and total energy loss across the valves was measured. RESULTS: Mean pressure difference with respect to root mean square forward flow decreased as the valve size increased. Thus effective orifice area increased as the valve size increased. The open leaflet configuration images showed that all three sizes of Mitroflow valves had a large circular orifice with minimal open leaflet deformation. All valves closed competently with no visible leakage and no closed regurgitant volume. The Mitroflow valves showed better effective orifice areas compared with previously tested frame-mounted porcine bioprostheses but lower effective orifice areas compared with porcine stentless bioprostheses; however, the open leaflet bending deformation was better than for any of the previously tested bioprosthetic valves. CONCLUSIONS: The hydrodynamic function of the Mitroflow Synergy stented pericardial bioprosthesis shows potential for good in vivo hemodynamic performance. The good hemodynamic performance combined with relative ease of implantation technique makes the pericardial valve a good valve in the aortic position, particularly in older patients with small annuli.     

Discrepancies Between Labeled and Actual Dimensions of Prosthetic Valves and Sizers

A bstract Background and aims : The hemodynamic performance of a mechanical or stented bioprosthetic valve is primarily determined by the diameter of its orifice. Thus, in aortic or mitral valve replacement, assessment of the native annular size and selection of the correspondingly sized prosthetic valve is necessary to achieve maximum hemodynamic performance. The purpose of this study was to determine the actual dimensions of aortic and mitral valve sizers and their corresponding prostheses, and to determine whether they differed from their marked dimensions. Methods : Mechanical and stented bioprosthetic valves and sizers were obtained from the manufacturers (CarboMedics, St. Jude, Medtronic-Hall, Starr-Edwards, Carpentier-Edwards, and Medtronic-Hancock), and the diameters were measured. Results : For the mechanical models, both aortic and mitral sizers were larger than their marked size by 0.5 mm to 1.0 mm. The aortic valves were all smaller than their corresponding sizers, but the relationship of the mitral valves to corresponding sizers varied with the manufacturer. For the bioprosthetic models the aortic and mitral sizers were true to marked size, the aortic valves were close to marked size and the mitral valves were smaller than marked size. Conclusions : These differences make optimal sizing difficult at best, particularly if more than one manufacturers' product is used in an institution. These differences may or may not impact valve performance in an individual surgeon's hands. However, the wide range of variations across prosthetic type and manufacturer obligate the surgeon to be aware of these variances to achieve maximum hemodynamic performance for each patient.     

Stentless bioprosthetic aortic valve replacement after a homograft root replacement: Toronto SPV implantation after a homograft root

Stentless bioprosthetic valves for the aortic position offer excellent hemodynamic characteristics, making them an attractive choice ahead of other valve prostheses. We present a unique case in which a patient underwent aortic valve replacement with a stentless porcine valve and mitral valve repair for severe aortic and mitral regurgitation 1 year after a homograft root replacement for acute aortic endocarditis. The rationale for our approach is outlined in the context of current surgical trends.     

Stentless bioprosthesis for aortic valve replacement

The stentless aortic bioprosthesis was reported to reduce left ventricular mass (LVM) in the early period after implantation and have better hemodynamic performance and a larger effective orifice area (EOA) than stented valves. However, its clinical advantage over the stented valve is still unclear. We have implanted stentless bioprostheses in 61 patients and had a low operative mortality rate (1.6%). LVM index, left ventricular end-diastolic volume (LVEDV) index, left ventricular end-systolic volume (LVESV) index, and peak pressure gradient (PG) were rapidly reduced after implantation. Ten-year-freedom from cardiac-related death, thromboemolism, and structural valve deterioration rates were 91.0%, 100%, and 95.0%, respectively. Furthermore, using MRI analysis, blood velocity through stentless valves was similar to that through native aortic valves in comparison with stented valves. In conclusion, the stentless valve enables more physiologic blood flow through the valve, and thus it may be useful in patients with small annuli or those who require better hemodynamic performance to enable physical activity.     

The hydrodynamic function and leaflet dynamics of aortic and pulmonary roots and valves: an in vitro study.

Fresh homograft aortic and pulmonary roots were tested in a pulsatile flow simulator to assess their hydrodynamic function and leaflet opening characteristics. Simultaneous flow and pressure measurements were obtained for a range of cardiac outputs. The effective orifice area and regurgitant volumes were calculated. The mean pressure difference across the pulmonary roots was obtained under both left and right side pressures. A video recording of valve leaflet function was also obtained for each valve. A comparison was made with four porcine bioprosthetic heart valves (21 and 23 mm). The mean pressure difference with respect to flow for the 21 mm Hancock II and Intact porcine bioprostheses was significantly higher than that for all aortic roots tested. The 24 mm aortic root showed significantly lower pressure drop compared to all porcine valves tested. The mean pressure difference across each pulmonary root at pulmonary pressures was significantly greater than at systemic pressures. At systemic pressures the fully open leaflets had a triangular orifice with low leaflet open bending strains at the commissures. At the lower internal pressures, with reduced dilation of the root, higher bending strains were noted. These were not as severe as seen in porcine valves.     

Hemodynamic assessment of the Carpentier-Edwards pericardial valve compared with the St. Jude Medical valve in the aortic position using dobutamine-stress echocardiography

To assess the hemodynamic performance of the prosthetic valve in the aortic position, we examined dobutamine-stress echocardiography (DSE) to the patients underwent AVR with CEP valve or SJM valve. In 23 mm size, there were no significant differences between CEP group and SJM group in Peak velocity of the aortic jet (PV), peak pressure gradient (PPG) and effective orifice area (EOA). On the other hand, in 21 mm size, PV and PPG of the CEP group were significantly lower than those of the SJM group after DSE. The EOA of the CEP group was significantly larger than that of the SJM group after DSE. Our results suggest that the hemodynamic function of the CEP valve is superior to that of the SJM valve especially in small aortic annuli.     

Aortic valve disease with severe ventricular dysfunction: stentless valve for better recovery

BACKGROUND: Stentless bioprostheses and homografts show better hemodynamic profiles compared with conventional stented bioprostheses and mechanical valves. Few data are available on stentless aortic valve implantation for patients with severe left ventricular dysfunction. The aim of this retrospective study was to assess the potential benefits of stentless aortic valve implantation for patients undergoing isolated aortic valve replacement with left ventricular ejection fraction < or = 35%. METHODS: From November 1988 through March 2000, 53 patients (45 men and 8 women, aged 64.2 +/- 15.2 years) with a LVEF < or = 35% (mean EF, 28.7 +/- 5.4%) underwent isolated, primary aortic valve replacement for chronic aortic valve disease. Twenty patients received stentless aortic valves and 33 patients received conventional stented bioprostheses and mechanical valves. Predictive factors for LVEF recovery at echocardiographic follow-up (36.2 +/- 32.1 months) were analyzed by simple and multiple regression analysis. RESULTS: There were no significant differences between groups in early and late mortality. Stentless aortic valve implantation required a longer aortic cross-clamp time (p = 0.037). The stentless aortic valve group showed a better LVEF recovery (p = 0.016). Stentless aortic valves had a larger indexed effective orifice area compared with conventional stented bioprostheses and mechanical valves (p < 0.0001). A smaller indexed effective orifice area (p = 0.0008), chronic obstructive pulmonary disease (p = 0.015), and implantation of a conventional stented bioprosthesis or mechanical valve (p = 0.016) were related to reduced LVEF recovery by univariate analysis. A larger indexed effective orifice area (p = 0.024) was an independent predictive factor for a better LVEF recovery by multivariate analysis. CONCLUSIONS: Stentless aortic valve implantation for patients with severe left ventricular dysfunction, even if technically more demanding, is a safe procedure that warrants a larger indexed effective orifice area leading to an enhanced LVEF recovery.     

Transcatheter heart valve with variable geometric configuration: in vitro evaluation

Clinically, the current transcatheter aortic valve (TAV) technology has shown a propensity for paravalvular leakage; studies have correlated this flaw to increased calcification at the implantation site and with nonideal geometry of the stented valve. The present study evaluated the hydrodynamics of different geometric configurations, in particular the intravalvular considerations. Three TAV devices were made to create a representative, size 26 mm TAV. Hydrodynamics were assessed using a pulse duplicator. The geometries tested were composed of the nominal, elliptical, triangular, and undersized shapes; along with half-constriction, a conformation in which only a portion of the stent was constrained. The TAVs were assessed for transvalvular pressure gradient (TVG), effective orifice area (EOA), and regurgitant fraction. The nominal-sized shape posed a larger TVG (6.2 ± 0.3 mm Hg) than other configurations (P < 0.001) except the undersized valves. EOA of the nominal sized TAV (1.7 ± 0.1 cm(2) ) was smaller than that of the triangular and half-elliptical versions (P < 0.001). The half- and full-undersized geometries had EOAs smaller than the nominal type (P < 0.001). Nominal shape had smaller regurgitation (6.7 ± 1.4%) than all configurations (P < 0.001) except for the half-undersized (4.0 ± 0.7, P < 0.001) with no statistically significant difference from the full-undersized (6.8 ± 1.3, P = 0.724). The testing of variable geometries showed significant differences from the nominal geometry with respect to TVG, EOA, and regurgitant fraction. In particular, many of these nonideal configurations demonstrated an increased intravalvular regurgitation.     

主动脉瓣置换术后人工心脏瓣膜-病人不匹配现象

目的 探讨主动脉瓣置换术后人工心脏瓣膜-病人不匹配(PPM)现象的发生率以及PPM与术后早期血流动力学和病死率的关系.方法 292例主动脉瓣置换手术(AVR)病人,参照人工瓣膜有效开口面积(EOA)和病人的体表面积计算有效开口面积指数(EOAI),EOAI＞0.85 cm2/m2不存在或仅有轻度的PPM;中度PPM 0.65≤EOAI≤0.85 cm2/m2;重度PPM EOAI＜0.65 cm2/m2.超声多普勒测量AVR术后主动脉瓣位平均跨瓣压差和血流速度,比较不同种类瓣膜(机械瓣和生物瓣)和不同大小瓣膜(＞21 mm和≤21 mm)AVR术后PPM发生率以及PPM与术后早期血流动力学、病死率的关系.结果 292例中机械瓣置换术219例,生物瓣置换术73例,两种术后中度PPM发生率分别为6.25%和48.22%(P＜0.01).置换＞21 mm人工瓣膜(191例)和≤21 mm人工瓣膜(101例)术后PPM发生率分别为13.61%和33.66%(P＜0.05).PPM组术后主动脉瓣平均跨瓣压差和平均流速[(26.50±6.25)mm Hg(1 mm Hg=0.133 kPa)和(2.66±0.87)m/s]显著高于非PPM组[(16.75±3.46)mm Hg和(1.58±0.47)m/s,P＜0.01].PPM组和非PPM组的术后早期病死率分别为6.67%和2.16%(P＜0.05).结论 AVR术后PPM现象普遍存在,尤其是置换生物瓣以及小瓣膜(≤21 mm)者.PPM影响术后瓣膜血流动力学,与术后早期病死率密切相关.