改性后的牛颈静脉带瓣管道在家犬中的实验研究

目的改性后的牛颈静脉带瓣管道植入狗的右室流出道，1年后观察其血流动力学和抗钙化性能。方法从屠宰场取新鲜牛颈静脉，筛选后放入循环固定槽内，用0．625％的戊二醛固定1d，取出分为2组，分别置入100％2，3-丁二醇和0．3％戊二醛中保存60d，然后分组植入狗的右室-肺动脉之间，将狗的肺动脉近端结扎，饲养1年后行血流动力学检查、组织病理学观察及钙含量测定。结果心脏超声和心导管及造影检查显示戊二醛组及2，3-丁二醇组的管道瓣膜活动均良好，且跨瓣压差小。2，3-丁二醇组管道内腔及瓣膜表面发现有内皮样细胞存在。戊二醛组和2，3-丁二醛组的管道组织均存在较严重的炎性反应。2，3-丁二醇组改性后的牛颈静脉管壁平均钙含量为（8．72±0．71）ug／mg，明显比戊二醛组的平均钙含量（22．05±10．78）ug／mg低（P〈0．05）；瓣膜平均钙含量（1．38±0．86）ug／mg，与戊二醛组（0．88±0．69）ug／mg比较，差异无显著性意义（P〉0．05）。结论戊二醛鞣制的牛颈静脉带瓣管道在体实验证实其有较理想的血流动力学性能；戊二醛鞣制的生物组织材料经2，3-丁二醇改性后可明显减轻组织钙化程度。     

Minimally immunogenic decellularized porcine valve provides in situ recellularization as a stentless bioprosthetic valve

Currently used bioprosthetic valves have several limitations such as calcification and functional deterioration, and revitalization through cellular ingrowth is impossible. To overcome these obstacles, we have developed a minimally immunogenic tissue-engineered valve that consists of an unfixed, decellularized porcine valve scaffold capable of being spontaneously revitalized in vivo after implantation. Porcine aortic root tissue was decellularized using detergents such as sodium lauryl sulfate and Triton X-100. The porcine valve was treated very gently and plenty of time was allowed for constituents to diffuse in and out of the matrix. In a preliminary study, a piece of decellularized porcine valve tissue was implanted into the rat subdermal space for 14 and 60 days and the structural integrity and calcification were evaluated. As an in vivo valve replacement model, the decellularized porcine valve was implanted in the pulmonary valve position in dogs and functional and histological evaluation was performed after 1, 2, and 6 months. Histological examination showed that the newly developed detergent treatment effectively removed cellular debris from the porcine aortic tissue. Decellularized porcine valve tissue implanted subdermally in rats showed minimal inflammatory cell infiltration and calcification. In the valve replacement model, spontaneous reendothelialization and repopulation of the medial cells were observed within 2 months, and good valve function without regurgitation was observed by echocardiography up to 6 months. The minimally immunogenic decellularized porcine valve proved effective in mitigating postimplant calcification and provided a suitable matrix for revitalizing prostheses through in situ recellularization, cellular ingrowth, and tissue remodeling.     

RhBMP-2诱导犬气管移植体软骨再生的实验研究

目的 探讨重组人骨形态发生蛋白-2（rhBMP-2）植入犬气管移植体内诱导软骨再生效果。方法 12只犬随机等分两组，分别将rhBMP-2／胶原（collagen）或胶原植入犬气管移植段，进行自体移植，通过HE染色、Masson’s染色、免疫组化检测软骨再生。18只犬随机等分为6组，给予不同浓度的rhBMP-2，利用HPIAS-1000高清晰度彩色病理图像分析仪测定各组新生软骨的面积，确定最佳诱导浓度。12只犬随机等分成2组，分别进行自体、异体移植并植入rhBMP-2，测定各组移植段气管管腔及新生软骨面积。结果 rhBMP-2／胶原植入气管移植段后，可以在植入区及固有软骨的软骨膜处诱导软骨再生，新生软骨面积与对照组差异有统计学意义（P〈0．01）。rhBMP-2剂量与新生软骨面积呈剂量依赖关系，当rhBMP-2浓度为5mg/ml时，其诱导的新生软骨面积最多。在自体移植与异体移植实验中，植入rhBMP-2后，移植段气管管腔的狭窄情况均较对照组得到改善。结论 rhBMP-2可促进气管移植体软骨再生，其诱导作用不仅可以促进植入区的软骨再生，而且通过软骨细胞间的接触促进了软骨膜处的软骨再生。可见rhBMP-2可以促进移植段气管的软骨再生，克服气管移植段的软化狭窄。     

生物瓣膜失功能原因分析

目的对植入人体内1年以上损坏的生物瓣膜作损坏原因的临床分析。方法1993年6月至2004年6月,共41例(47只)生物瓣膜失功能病人行再次手术换瓣。两次换瓣间隔时间1~16年,平均(9.7±4.1)年。对失功能生物瓣膜进行标本观察及病理学检测。结果47只带支架生物瓣膜中,瓣架无一损坏,42只瓣膜发生瓣叶撕裂或穿孔,35只有不同程度的钙化现象,且在瓣环表面和瓣脚周围有纤维组织增生,2只瓣膜有赘生物及血栓形成;47只生物瓣膜中损坏较重的瓣膜送病理学检查发现大量吞噬细胞和单核细胞浸润。结论生物瓣膜早期损坏以破损撕裂为主,晚期以钙化和破损撕裂等多种因素的复合病损结果出现。     

老年风湿性二尖瓣病变行二尖瓣修复术与生物瓣膜置换术中期效果比较

目的比较60岁以上老年患者风湿性二尖瓣修复(MVP)与生物瓣膜置换(MVR)的中期效果。方法选取2014年1月至2016年1月北京安贞医院瓣膜外科诊疗中心行风湿性二尖瓣修复或生物瓣置换手术的60岁以上老年风湿性二尖瓣病变患者,包括同期行三尖瓣修复术及房颤射频消融术患者;排除合并主动脉瓣手术、冠状动脉旁路移植手术、二次手术患者,最终纳入患者82例。根据二尖瓣手术方式分为二尖瓣修复组(MVP组,25例)和生物瓣置换组(MVR组,57例)。采用Kaplan-Meier法进行生存分析并绘制曲线,通过Log Rank方法比较两组患者5年生存率的差异。结果围手术期全组患者平均年龄(66.37±4.41)岁。54.9%的患者心功能(NYHA分级)Ⅲ级。两组患者在体外循环时间(P=0.99),主动脉阻断时间(P=0.88),术后住院时间(P=0.76)差异均无统计学意义。MVR组3例患者住院期间死亡,病死率5.3%;MVP组无住院期死亡(P=0.24)。随访5年,最长随访63个月,平均随访47.03个月。MVR组6例死亡,其中4例死于心脑血管不良事件,2例死于非心脑血管不良事件。MVP组无死亡。两组均无再手术病例。结论风湿性二尖瓣病变的老年患者采用二尖瓣修复手术治疗能够获得较好的中期效果。     

Mid-term clinical and haemodynamic results after aortic valve replacement with the Trifecta bioprosthesis

 Open in a separate windowOBJECTIVESThe aim of this study was to evaluate the clinical and haemodynamic results after implantation of the Trifecta bioprosthesis.METHODSThis study is a retrospective analysis of all patients undergoing Trifecta aortic valve replacement between 01 January 2012 and 31 December 2017 at the Ghent University Hospital. Univariable and multivariable analyses were performed to identify predictors of valve- and procedure-related complications and mortality. The haemodynamic performance was analysed by longitudinal Doppler echocardiography.RESULTSThe mean age of the 182 patients was 77 [standard deviation (SD): 5.5] years; 54.9% were women. The mean follow-up was 39.8 (SD: 24.3) months. Overall survival at 1 and 5 years was 86% (SD: 3%) and 68% (SD: 4%), respectively, and overall freedom from structural valve deterioration was 100% and 98% at 1 and 5 years, respectively. There was no valve thrombosis nor early endocarditis. Urgent surgery was the only risk factor for early mortality in the multivariable analysis [P = 0.009, odds ratio 0.06, 95% confidence interval (CI) 0.01–0.5]. Preoperative atrial fibrillation was the most important predictor of late mortality (P = 0.001, hazard ratio 3.68, 95% CI 1.65–8.21). The average peak gradients were stable from discharge up to 1 and 5 years postoperatively [15 (SD: 6) and 17 (SD: 8) mmHg].CONCLUSIONSThese results confirm the excellent clinical performance of the Trifecta valve, particularly in an elderly age group. Through the 7-year follow-up period, low transvalvular gradients persisted, and only a few patients needed reoperation. Although structural valve degeneration occurred rarely, it was unrelated to valve size or age at implantation; therefore, further long-term follow-up remains mandatory.     

The Chemical Protecting Group Concept Applied in Crosslinking of Natural Tissues with Glutaraldehyde Acetals

This work describes the results of the controlled crosslinking of collagen matrices by glutaraldehyde based on a double protection strategy, glutaraldehyde acetals and lysine protonation due to the acidic conditions of acetal formation. Materials crosslinked by this approach were characterized by thermal stability comparable to those obtained by conventional procedures with mechanical properties expected for bioprosthesis manufacture and with a higher stability toward collagenase hydrolysis. The integrity of the microfibrillar structure was confirmed by optical and scanning electronic microscopy. The results indicate that the glutaraldehyde acetals procedure may be of potential use for the crosslinking of bovine pericardium used in the manufacture of bioprosthetic devices. Advantages may be related to the production of materials with homogeneous crosslinking distributions, associated with better definition in the nature of the chemical link that they introduce, due to a better distribution of glutaraldehyde within the tissue matrix before the crosslinking reaction is allowed to occur. As a result, materials with improved biological and mechanical properties are expected.     

主动脉瓣生物瓣膜安全性的系统评价与meta分析

目的 采用系统评价和meta分析的方法评价主动脉瓣置换术中使用生物瓣膜的远期安全性结局。方法 计算机系统检索Medline、Embase、Web of Science、CENTRAL、ClinicalTrial.gov、SinoMed、中国知网、维普和万方数据库在2000年1月1日至2019年1月26日期间发表的随机临床试验、非随机临床试验、队列研究和病例系列研究,纳入标准还包括使用生物瓣膜进行主动脉瓣膜置换术、平均随访时间≥5年、报告了相关安全性结局等。提取研究特征和相关数据,使用Stata 14.0进行meta分析。结果 最终纳入53篇文献共57个研究组,包含47 803名患者。(1)全因死亡率为6.33/100人年(95%CI:5.85~6.84),亚组分析结果显示,猪瓣膜和牛心包瓣膜的死亡率分别为5.69/100人年(95%CI:5.05~6.41)和7.29/100人年(95%CI:6.53~8.13);有支架和无支架瓣膜的死亡率分别为6.69/100人年(95%CI:6.12~7.30)和5.21/100人年(95%CI:4.43~6.14)。(2)血栓栓塞的发生率为1.16/100人年(95%CI:0.96~1.40),心脏起搏器植入率为1.08/100人年(95%CI:0.75~1.54),再手术率为0.77/100人年(95%CI:0.65~0.91),脑卒中的发生率为0.74/100人年(95%CI:0.51~1.06),结构性瓣膜退化的发生率为 0.73/100人年(95%CI:0.59~0.91),大出血的发生率为0.52/100人年(95%CI:0.41~0.65),心内膜炎的发生率为0.38/100人年(95%CI:0.33~0.44),非结构性瓣膜退化的发生率为0.20/100人年(95%CI:0.13~0.31)。结论 生物瓣膜的全因死亡率为6.33/100人年,血栓栓塞、心脏起搏器植入、再手术、脑卒中和结构性瓣膜退化是主要的远期并发症。     

The Mosaic Mitral Valve Bioprosthesis: A Long-Term Clinical and Hemodynamic Follow-Up

We reviewed the cases of 100 patients (mean age, 73 ± 10 yr; 64 men) who had mitral valve replacement with a Medtronic Mosaic porcine bioprosthesis from 1995 through 2011. The mean New York Heart Association (NYHA) class was 3 ± 0.7, and 52 patients were in atrial fibrillation. Prosthetic sizes were chiefly 27 mm (50 patients) and 29 mm (40 patients). Follow-up ended in December 2012 and is 97% complete, with a cumulative duration of 611 patient-years (mean duration, 6 ± 4.6 yr; maximum, 17.7 yr).The early mortality rate was 10% (6% in elective patients); late deaths occurred in 31 patients (5 valve-related). Actuarial survival rates at 5, 10, and 15 years were 74% ± 5%, 50% ± 6%, and 37% ± 8%. The mean NYHA class in survivors was 1.4 ± 0.6 (P <0.0001). Thromboembolic episodes occurred in 4 patients, with an actuarial freedom at 15 years of 91% ± 5%. No cases of endocarditis were observed. Four patients needed reoperation, 2 for structural failure, and 1 each for perivalvular leakage and valve thrombosis. Actuarial freedom from structural failure and from reoperation, respectively, was 93% ± 5% and 91% ± 5% at 15 years. Echocardiographic follow-up in 24 patients with 27-mm prostheses showed a mean gradient of 5 ± 1.7 mmHg and an effective orifice area of 1.57 ± 0.3 cm²; in 16 patients with 29-mm prostheses, the mean gradient was 4.5 ± 1.9 mmHg, and the effective orifice area, 1.63 ± 0.4 cm².During nearly 17 years of follow-up, the Mosaic bioprosthesis has shown good overall clinical and hemodynamic performance after mitral valve replacement.