扩大端侧吻合一期矫治208例小儿主动脉缩窄合并室间隔缺损的疗效

目的总结本中心近年来以扩大端侧吻合法一期矫治小儿主动脉缩窄合并室间隔缺损的手术疗效及经验。方法选取2010年1月—2017年10月在本院行一期手术治疗的主动脉缩窄合并室间隔缺损的患儿,共208例,其中男性137例,女性71例,中位年龄54(5～730)天,中位体质量4.0(1.8～9.9)kg。胸骨正中单一切口下,以扩大端侧吻合矫治主动脉缩窄,同期修补室间隔缺损。所有手术由同一组外科医师完成。应用SPSS 20.0统计软件进行数据录入和分析。结果术后早期死亡6例(2.9%),晚期死亡3例(1.4%);再缩窄16例(7.7%),再手术19例(9.1%)。脑钠肽在术前即存在明显升高,但术后未发生明显变化;主动脉缩窄段压差在术后明显下降,经皮血氧饱和度在术后明显上升。C反应蛋白、乳酸和肌酐水平在术后明显上升。术前合并高血压104例(53.0%),术后血压降至正常30例(28.8%),术后血压继续升高35例(33.7%)。术后吻合口压差较高是术后再缩窄的高危因素。结论胸骨正中单一切口下,扩大端侧吻合法一期矫治主动脉缩窄合并室间隔缺损,死亡率和再缩窄率低,取得良好的近中期疗效。术后吻合口压差较高是主动脉缩窄复发的高危因素。     

枝化状聚乙二醇交联改善猪去细胞主动脉瓣的力学性能比较

目的 采用不同相对分子质量枝化状聚乙二醇(PEG)交联巯基化的猪去细胞瓣,观察其对去细胞瓣膜力学性能的影响.方法 将25例猪去细胞主动脉瓣随机分为5组:PEG3400组、PEG8000组、PEG12000组、PEG20000组和对照组,常温反应时间4 h.测定残余巯基计算交联效率;静态拉伸实验测定力学性能.结果 4 h交联率依次为92.40%、89.88%、87.87%和87.46%,相对分子质量越小,交联效率越高,PEG3400组与其他各组比较,差异有统计学意义(P＜0.05);力学测试显示,相对分子质量越大,力学强度越高,呈一定的正相关,PEG12000和PEG20000组抗拉强度分别为(3.22±0.41)MPa和(3.19±0.15)MPa,与对照组比较,差异有统计学意义(P＜0.05).结论 相对分子质量12000 Da和20000 Da枝化状聚乙二醇交联可有效改善猪去细胞瓣的力学性能,有望用于构建新型复合的组织工程瓣膜支架材料的研究应用.

Abstract：

Objective Branched polyethylene glycols (PEG) with different molecular weight were cross-linked to the porcine decellularized aortic valve (DAV) and the effects of PEG cross-linking on the mechanical properties were investigated. Methods A total of 25 porcine DAVs were randomly assigned into 5 groups: PEG3400, PEG8000, PEG12000, PEG20000 and control. The reactive time was 4 h at room temperature. The efficiency of crosslinking was calculated by measuring the residual thiol group. The mechanical properties were obtained by static tensile test. Results The efficiency of crosslinking was 92. 40% , 89. 88% , 87. 87% and 87. 46% in PEG3400, PEG8000, PEG12000, PEG20000 groups, respectively. As compared with other groups, the PEG3400 group had significantly greater increase in the crosslinking degree (P ＜ 0. 05). Tensile test showed the tensile strength of PEG12000 and PEG20000 groups was (3. 22 ±0.41) and (3. 19 ±0. 15) MPa, respectively, and significantly different from that in control group (P ＜ 0. 05). The tensile strength and young' s modulus had a positive correlation with the molecular weight of PEG. Conclusion Branched PEG with the molecular weight of 12 000 Da and 20 000 Dacan effectively crosslink to the porcine decellularized aortic valves and improve their mechanical behaviors, and has the potential to be used as the material of fabricating new hybrid scaffold of tissue engineering heart valves.     

枝化状聚乙二醇对牛跟腱Ⅰ型胶原结构与构象稳定性的影响

目的 观察枝化状聚乙二醇对牛跟腱Ⅰ型胶原结构与构象稳定性的影响.方法 以牛跟腱Ⅰ型胶原为原料,以枝化状聚乙二醇为交联剂,在有效交联的前提下,通过测定羟脯氨酸含量观察聚乙二醇交联对胶原酶解稳定性的影响,采用示差扫描量热法(DSC)观察胶原热变性温度,采用圆二色光谱法(CD)观察聚乙二醇对胶原三螺旋构象稳定性的影响.结果 枝化状聚乙二醇交联组24 h降解率为26.79%,而对照组则达97.39%,两者比较差异有统计学意义(P＜0.05).交联组热变性温度为(79.1±1.2)℃,与对照组(68.6±1.9)℃比较,差异有统计学意义(P＜0.05);CD谱测定特征性吸收峰差异无统计学意义(P＞0.05).结论 枝化状聚乙二醇可显著提高其热变形温度和抗酶性分解能力,而对其三螺旋结构与构象无明显不利影响,是较理想的生物高分子交联剂,可有望用于胶原分子的交联改性.

Abstract：

Objective The triple helix of collagen is the basis of its biological function, such as cell adhesion and tissue remodeling. Crosslinking of collagen with chemical agent will improve the biomechanical properties. However, the effects of differernt crosslinking agents on the structure and conformation stability of type Ⅰ collagen are rarely investigated. Methods The branched polyethylene glycol ( PEG)derivative ( MW 12 kD) was used as crosslinking agent, and allowed to react with bovine achilles' s tendon type Ⅰ collagen modified by succinimidylacetylthioacetate (SATA). The ability of resistance of crosslinked collagen to enzymatic degradation was investigated by measuring the release of hydroxyproline, and differential scanning calorimeter ( DSC ) was taken to determine the thermal denaturation temperature. The effect of PEG on the riple helix of collagen was studied by circular dichroism ( CD) . Results The resistance ability of PEG crosslinked collagen was strongly enhanced when compared with that of control group ( P ＜0. 05 ) , and the thermal denaturation temperature was also significantly rised. CD demonstrated that PEG crosslinking did not result in the destruction of the triple helix conformation of type Ⅰ collagen. Conclusion Branched PEG derivative used in this study is a promising polymer crosslinking agent that may be utilized in the modification of type Ⅰ collagen.     

血管内皮细胞生长因子修饰的聚乙二醇化去细胞瓣构建心脏瓣膜复合支架

目的对去细胞瓣进行聚乙二醇(PEG)化改性和血管内皮细胞生长因子(VEGF)共价修饰,以改善去细胞瓣力学性能和生物学性能,并联合内皮祖细胞构建心脏瓣膜复合支架。方法枝化状PEG末端的丙烯酰基与引入到去细胞瓣上的巯基,通过迈克尔加成反应完成去细胞瓣的PEG化,并作去细胞瓣PEG化前后以及天然主动脉瓣的生物力学测定;通过PEG化去细胞瓣上未饱和的丙烯酰基与VEGF中半胱氨酸残基上的巯基发生另一个迈克尔加成反应,对去细胞瓣进行VEGF共价修饰,免疫荧光测定VEGF修饰效果;在VEGF修饰的PEG化去细胞瓣、去细胞瓣和PEG化去细胞瓣上种植内皮祖细胞(EPCs),培养10d后行瓣膜上DNA含量测定、苏木素-伊红染色和扫描电镜。结果力学测试显示:PEG化去细胞瓣的最大抗张强度较单纯去细胞主动脉瓣明显提高(P<0.05),而与天然主动脉瓣相比无差异(P>0.05);免疫荧光检测显示:VEGF可有效地共价修饰PEG化去细胞瓣;与PEG化去细胞瓣和单纯去细胞瓣相比,VEGF修饰的PEG化去细胞瓣明显促进EPCs的增殖,并且可在瓣膜表面形成一层连续的单细胞层。结论 PEG化可明显改善去细胞瓣的力学性能,并且VEGF修饰PEG化去细胞瓣可促进支架上黏附细胞的增殖,有利于改善组织工程心脏瓣膜的构建。     

基质金属蛋白酶-2敏感型聚乙二醇复合水凝胶的制备及性质

目的 采用相对分子质量20000 Da分枝状聚乙二醇(four-armed PEG-Ac)和基质金属蛋白酶-2(MMP-2)敏感型底物肽制备一种可降解复合水凝胶,并检测其性能.方法 以制备浓度为10％ (w/v)的酶敏感型复合PEG水凝胶为实验A组,单纯PEG水凝胶为对照B组,比较两种水凝胶在37℃磷酸盐缓冲液(PBS)和血清的降解,并检测细胞毒性.在制胶过程中包埋转化生长因子(TGF-β1),观察两组水凝胶对TGF-β1的缓释效果.结果 PBS中A、B两组4周累计降解率分别为78.36％、76.28％,两者差异无统计学意义(P＞0.05)；分别添加正常人体血清,A组4周累计降解率为88.35％,降解速度加快,B组则变化不明显.噻唑蓝(MTT)比色法检测复合PEG水凝胶无细胞毒性.A、B两组水凝胶TGF-β17 d累计释放率分别为50.63％、44.36％,两者差异无统计学意义(P＞0.05),分别添加MMP-2后,A组对TGF-β1的释放速度明显加快.结论 MMP-2敏感型PEG水凝胶结构稳定,对细胞无毒性,包埋TGF-β1有良好的控释效果,有望应用于新型组织工程心脏瓣膜支架材料的研制.     

枝化状聚乙二醇交联改善猪去细胞主动脉瓣的力学性能比较

Objective Branched polyethylene glycols (PEG) with different molecular weight were cross-linked to the porcine decellularized aortic valve (DAV) and the effects of PEG cross-linking on the mechanical properties were investigated. Methods A total of 25 porcine DAVs were randomly assigned into 5 groups: PEG3400, PEG8000, PEG12000, PEG20000 and control. The reactive time was 4 h at room temperature. The efficiency of crosslinking was calculated by measuring the residual thiol group. The mechanical properties were obtained by static tensile test. Results The efficiency of crosslinking was 92. 40% , 89. 88% , 87. 87% and 87. 46% in PEG3400, PEG8000, PEG12000, PEG20000 groups, respectively. As compared with other groups, the PEG3400 group had significantly greater increase in the crosslinking degree (P ＜ 0. 05). Tensile test showed the tensile strength of PEG12000 and PEG20000 groups was (3. 22 ±0.41) and (3. 19 ±0. 15) MPa, respectively, and significantly different from that in control group (P ＜ 0. 05). The tensile strength and young' s modulus had a positive correlation with the molecular weight of PEG. Conclusion Branched PEG with the molecular weight of 12 000 Da and 20 000 Dacan effectively crosslink to the porcine decellularized aortic valves and improve their mechanical behaviors, and has the potential to be used as the material of fabricating new hybrid scaffold of tissue engineering heart valves.     

聚乙二醇改性去细胞猪主动脉瓣膜构建复合支架及其体外细胞毒性试验

目的 对去细胞猪主动脉瓣膜进行聚乙二醇(PEG)化改性,并评价改性后复合支架的细胞毒性.方法 合成功能基团为丙烯酰基的枝化状聚乙二醇衍生物,在去细胞猪主动脉瓣膜引入巯基,通过迈克尔加成反应完成PEG对去细胞猪主动脉瓣膜的交联,并作PEG改性前后瓣膜的生物力学测定.制作去细胞瓣膜的浸提液,浸提液分为单纯去细胞瓣膜组、PEG改性去细胞瓣膜组和阴性对照组(培养液),采用CCK-8法检测复合支架的浸提液对人脐静脉内皮细胞增殖率的影响,评价其细胞毒性.结果 PEG改性去细胞瓣膜反应条件温和,改性效果确切.复合瓣膜支架的抗拉强度明显高于去细胞瓣膜[(7.53±0.29)MPa比(5.65±0.24)MPa,P＜0.05],但与天然瓣膜[(7.68±0.20)MPa]差异无统计学意义(P＞0.05).复合支架和去细胞瓣膜毒性评级均0级,与阴性对照组差异无统计学意义(P＞0.05).人脐静脉内皮细胞经各浸提液的培养液培养后形态良好,增殖旺盛.结论 PEG改性能明显改善去细胞猪主动脉瓣膜的力学性能,且改性后的复合支架无细胞毒性,为进一步研究提供依据.     

基于倾向指数匹配法回顾比较无血体外循环手术后是否输注库存红细胞对患儿的短期影响

目的比较无血体外循环(CPB)术后是否输注库存红细胞对先天性心脏病患儿术后短期的影响。方法纳入2017年1月至2018年4月在本院行CPB下未输注异体血心脏直视手术患儿的临床资料。依据CPB术后是否输注库存红细胞分为A、B两组。采用倾向性评分匹配法筛选术前资料基线值一般的患者,最终两组各纳入45人。比较两组术后不同时间点的血液学监测结果以及其他围术期资料。结果患儿术后第一天、术后第三天血红蛋白、红细胞比容A组均高于B组,血小板A组均低于B组; A组术后第三天红细胞浓度也显著高于B组;术后第1天血清氨基末端脑钠肽前体、丙氨酸氨基转氨酶A组均高于B组; A组术后CCU停留时间及住院费用也显著高于B组,术后呼吸机辅助时间及住院时间均无差异。结论无血预充CPB心脏术后不输库存红细胞可以较好地维持血小板数量,对肝功能影响较小,且CCU停留时间短,住院花费低,可安全用于临床,值得推广。临床不合理用血现象仍存在,需更新观念,加强围术期各部门合作,减少不合理用血,以达到节约用血,保护患者的目的。     

自发性食管破裂1例分析

笔者收治自发性食管破裂1例，分析如下。 1病历摘要 男，52岁。2008—01—19因19d黑便一次，恶心、呕吐半月，突发左胸痛0．5d急诊入院，为当日清晨5：oo许呕吐胃内容物10m1后突发左侧胸痛，伴心慌、胸闷、气促。既往胃病史20a余，自服药物后好转。入院时查体：T37．7℃，P132次／min，BP114／86mmHg。胸廓无畸形；左侧呼吸运动减弱；左侧触诊语颤减弱；左上叩诊稍呈鼓音，左下叩诊呈浊音；左侧呼吸音消失，右侧呼吸音粗糙。腹平软，无压痛及反跳痛，     

外科手术治疗主动脉缩窄合并复杂心脏畸形79例单中心回顾性分析

目的 总结主动脉缩窄合并复杂心脏畸形的手术治疗效果。方法 回顾性分析2010年1月19日—2017年9月7日于广州市妇女儿童医疗中心住院治疗的主动脉缩窄合并复杂心脏畸形79例患儿的临床资料,其中男52例、女27例,中位年龄71 d,中位体重4.3 kg。术前合并气管狭窄26例,术前气管插管7例。采取胸骨正中切口入路,以扩大端侧吻合矫治主动脉缩窄,同期处理合并心脏畸形。所有手术由同一组外科医师完成。结果 中位深低温停循环时间18(13～28) min,中位主动脉阻断时间62(15～199) min,中位体外循环时间145(71～674) min;中位术后机械通气时间72(9～960) h,中位ICU滞留时间144(12～1 944) h,中位总住院时间24(2～93) d;早期死亡9例,晚期死亡5例;再手术28例,再缩窄10例。主动脉缩窄段压差在术后明显下降;经皮血氧饱和度、C-反应蛋白（CRP）、乳酸和肌酐水平在术后明显上升。与非死亡组相比,死亡组的术前和术后即刻血氧饱和度均较低,而术后即刻脑钠肽（BNP）和CRP均较高。结论 胸骨正中单一切口下,以扩大端侧吻合法矫治主动脉缩窄,同期处...