Percutaneous Pulmonary Valve Placement

Patients with congenital heart disease and pulmonary valve disease need multiple procedures over their lifetimes to replace their pulmonary valves. Chronic pulmonary stenosis, regurgitation, or both have untoward effects on ventricular function and on the clinical status of these patients. To date, all right ventricle–pulmonary artery conduits have had relatively short lifespans. Percutaneous pulmonary valve implantation, although relatively new, will probably reduce the number of operative procedures that these patients will have to undergo over a lifetime. Refinement and further development of this procedure holds promise for the extension of this technology to other patient populations.     

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。     

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。     

Mid-term clinical and health-related quality of life outcomes for the Trifecta bioprosthesis

BackgroundThe Trifecta valve has been reported to have excellent hemodynamics. Controversy exists on occurrence of patient-prosthesis mismatch (PPM) and data on mid-term outcome is sparse. Health-related quality of life (HRQoL) assessment for the Trifecta valve has not been reported before. The aim of this study was to report the mid-term clinical and HRQoL outcomes in patients undergoing Trifecta valve implantation at our institution.MethodsIn this prospective, observational study, patients undergoing an aortic valve replacement (AVR) using the Trifecta valve were included. Data collection was retrospective from prospectively collected institutional database. Clinical and echocardiographic data were collected prospectively during follow-up. Quality of life was assessed using the Short Form-36 (SF-36) questionnaire.ResultsForty-seven patients were included in the study of which 9 (19%) were women. Isolated AVR was carried out in 33 (70%) patients. In-hospital mortality and 30-day mortality were 1 (2.1%) and 2 (4.2%), respectively. With a mean indexed effective orifice area (iEOA) 0.96 ± 0.1, none of the patients had severe PPM. Moderate PPM was seen in 19%. The mean follow-up was 3 ± 1.7 years. The 5-year survival estimate was 83.2% in the overall cohort, 81.4% in the isolated and 87.5% in the concomitant procedure group. Freedom from re-operation and structural valve degeneration at 5 years was 95.7% and 97.8%. The mean physical health composite was 69.24 ± 2 and the mean mental health composite was 69.7 ± 25, indicating excellent mental and physical well-being among patients.ConclusionThe Trifecta valve provides satisfactory hemodynamics, survival and freedom from re-operation and excellent HRQoL at mid-term follow-up.     

羟基磷灰石人工听骨的临床应用研究

应用PORP和TORP两种类型羟基磷灰石（hydroxyapatite，HA）生物陶瓷人工听骨，对50例（50耳）残留性中耳炎及慢性中耳乳突炎病人进行听骨键重建的临床应用研究。HA的PORP在听骨槌镫间搭桥21耳；镫骨上加高（改良Ⅱ型鼓室成形术）18耳；HA的TORP应用于足板以上听骨链全缺病人的听骨链重建术11耳。术后病人随访0．5～5年，结果语言频率范围平均听力较术前提高10dBHL者5耳（10．0％）；15～20dBHL者22耳（44．0％），25～30dBHL以上者17耳（34．0％），听力提高总有效率为88.0％。所有病人均未表现对HA排斥现象，6耳失败者主要表现为人工鼓膜极度内陷，HA蘑菇头外突，并有前倾，但未脱出。本文就HA临床应用中取不同术式的效果及失败原因进行讨论。     

牛心包组织工程心脏瓣膜支架脱细胞方法的比较

目的对比去污剂-酶消化法、胰蛋白酶消化法和去氧胆酸钠法去除新鲜牛心包组织上细胞的效果和保护基质的能力，为组织工程心脏瓣膜的构建提供较满意的平台。方法应用3种方法处理新鲜牛心包组织，用光学显微镜、扫描电镜观察脱细胞效果和胶原纤维、弹力纤维改变；用热皱缩实验、拉力测试观察基质的物理性能变化；用DNA抽提比较脱细胞前后细胞数量差异。结果3种方法均能完全去除细胞，与去污剂-酶消化法比较，另2种方法对基质破坏明显。结论去污剂-酶消化法脱细胞效果好，且有良好的保护基质的能力。     

Micropatterned bioimplant with guided neuronal cells to promote tissue reconstruction and improve functional recovery after primary motor cortex insult

With the ever increasing incidence of brain injury, developing new tissue engineering strategies to promote neural tissue regeneration is an enormous challenge. The goal of this study was to design and evaluate an implantable scaffold capable of directing neurite and axonal growth for neuronal brain tissue regeneration. We have previously shown in cell culture conditions that engineered micropatterned PDMS surface with straight microchannels allow directed neurite growth without perturbing cell differentiation and neurite outgrowth. In this study, the micropatterned PDMS device pre-seeded with hNT2 neuronal cells were implanted in rat model of primary motor cortex lesion which induced a strong motor deficit. Functional recovery was assessed by the forelimb grip strength test during 3 months post implantation. Results show a more rapid and efficient motor recovery with the hNT2 neuroimplants associated with an increase of neuronal tissue reconstruction and cell survival. This improvement is also hastened when compared to a direct cell graft of ten times more cells. Histological analyses showed that the implant remained structurally intact and we did not see any evidence of inflammatory reaction. In conclusion, PDMS bioimplants with guided neuronal cells seem to be a promising approach for supporting neural tissue reconstruction after central brain injury.     

Transapical implantation of a self-expanding aortic valve bioprosthesis — animal feasibility study

Background: Severe peripheral arterial disease may pose a limitation to the applicability of trans-arterial aortic valve implantation in patients who are otherwise candidates. For this reason, transapical aortic valve implantation has been proposed as a possible alternative. Objective: To evaluate the acute safety and performance of a specially designed delivery system, the CoreValve Tranzap™ delivery catheter, for the transapical implantation of a self-expandable aortic valve prosthesis in a porcine animal model. Methods: Thirteen pigs were implanted with a self-expandable aortic valve bioprosthesis using a 21F catheter delivery system through a transapical approach. The delivery system was evaluated for: (1) the ability to access the implantation site; (2) the ability to precisely position the delivery catheter; (3) control of the delivery of the prosthesis; (4) safe retrieval of the delivery catheter; and (5) the ability to close the apical access site of the heart. Results: Successful implantation was achieved in 100% of the cases. The following points were achieved in all animals: (1) passage of the delivery catheter through an incision in the left ventricular apex; (2) positioning of the delivery catheter on the implantation site; (3) controlled deployment of the aortic valve prosthesis; (4) the safe retrieval of the delivery catheter system; and (5) the adequate closure of the apex of the heart. Conclusion: This study demonstrates the acute safety and feasibility of the CoreValve Tranzap™ delivery system for the transapical implantation of the CoreValve self-expanding aortic valve bioprosthesis in a porcine animal model.