人工心脏辅助装置硬段相改性新型聚氨酯材料的血液相容性

Haemo-compatibility of new hard-segment modified polyurethane of man-made heart assist devise

目的:应用硬段相改性的新型聚氨酯材料建立犬心脏辅助转流模型,观察这种用于制造人工心脏辅助装置的新型材料与血液的相容性。方法:实验于2002-03/2004-12在西京医院完成。选取杂种成年犬12只,随机分为硬段相改性新型聚氨酯材料组和未改性医用聚氨酯材料组,6只/组。①两组动物采用戊巴比妥钠肌肉注射麻醉后,气管插管呼吸机辅助呼吸,股静脉置管测中心静脉压及输液,股动脉插入动脉测压管并接生理监护仪有创压换能器,四肢连接监护仪心电标准肢体导联电极。②犬仰卧位,正中切口开胸,悬吊心包,肝素化后于升主动脉插入人工辅助装置血泵主动脉供血管,于左心耳插入引流管,分别连接血泵出入口。为防止出现心律失常,给予利多卡因100mg静推,以自行研制的动力装置给予辅助装置动力支持。③硬段相改性新型聚氨酯材料组选用材料硬度90A的硬段相改性医用聚氨酯,未改性医用聚氨酯材料组选用未改性的医用聚氨酯材料建立犬心脏辅助转流模型,分别测定两组材料表面对血小板的黏附情况。④于左心辅助转流开始后0,1,4,12,24,48,72h检测两组动物游离血红蛋白含量的变化以及纤维蛋白原、白蛋白的吸附情况。结果:实验选取杂种成年犬12只,全部进入结果分析。①两组血小板黏附情况:与未改性医用聚氨酯材料组比较,硬段相改性新型聚氨酯材料组表面血小板黏附数量明显减少犤(12.5±2.7),(5.2±1.2)/视野,P<0.01犦。②两组左心辅助转流后不同时间点游离血红蛋白含量的变化:左心辅助转流4h前两组材料对血液破坏程度均较轻,组间比较基本相似(P>0.05)。4h后未改性医用聚氨酯材料组游离血红蛋白含量明显升高,而硬段相改性新型聚氨酯材料组游离血红蛋白含量上升趋势缓慢(P<0.05)。③两组左心辅助转流后不同时间点吸附纤维蛋白原吸光度值的比较:两组材料随转流时间的延长,对纤维蛋白原的吸附含量均逐渐增加,但硬段相改性新型聚氨酯材料组在左心辅助转流后各时间点吸附纤维蛋白原均低于未改性医用聚氨酯材料组(P<0.05)。④两组左心辅助转流后不同时间点吸附白蛋白吸光度值的比较:两组材料随转流时间的延长,对白蛋白的吸附含量均逐渐增加,但硬段相改性新型聚氨酯材料组在左心辅助转流后各时间点吸附白蛋白均高于未改性医用聚氨酯材料组(P<0.05)。结论:硬段相改性的新型医用聚氨酯材料比未改性的常见医用聚氨酯材料更具有良好的血液相容性,可作为人工心脏辅助装置的首选材料进一步推广应用。

AIM： To establish dog models of ventricular assistant bypass with new hind-segment modified polyurethane （PU）, and observe the compatibility of blood and new material used in making human ventricular assist device （VAD）. METHODS： The experiment was carried out in Xijing Hospital from March 2002 to December 2004. Twelve random-breed adult dogs were selected and randomly divide into hard-segment modified PU group （group A） and pure PU group （group B） with 6 dogs in each group. ①Dogs in two groups received anesthesia by intramuscularly injected of continual, respiring with trachea cannula breathing machine. Assayed the central venous pressure （CVP） by locating tubes in femoral vein and transfusing, inserted the pressure assaying tube of artery into femoral artery （FA） and connected with physiological monitor of mean energy transducer, connected four limbs with electrocardio-standard-limb lead electrodes of the monitor.② Breasts of dogs lying on supine position were opened by conducting median incision and their camera cordis were suspended. After heparinisation, the ascending aorta （AO） was inserted of man-made assistant devise blood pump arterial line, the drainage tube was inserted into left atrial appendage （LAA） and respectively connected with the entrance and exit of blood pump. To prevent arrhythmia, venous injection of 100 mg dolicaine was conducted; The assistant service was supported by self-made dynamic device. ③Dog models of ventricular assistant bypass were established in group A by applying 90A hard-segment modified PU and established in group B by applying pure PU. Attachments of the material surface in two groups to platelet were respectively assayed. ④0, 1,4,12,24,48,72 hours after assistant bypass of the cor sinistrum, changes of the contents of free hemoglobin （FreeHb）, sticking status of fibrinogen and albumin in animals of beth groups were tested. RESULTS： Twenty included dogs in the experiment were involved in the analysis of results. ①Attachments of platelet in two groups： Compared with group B, the number of attachment in group A was significandy decreased [（12.5±2.7）, （5.2±1.2）/field,P 〈 0.01]. ②Changes of the contents of freeHb in different time-peints after cor sinistrum assistant bypass in both groups： Destructions of materials in the two groups on blood 4 hours before cor sinistrum assistant bypass were slight, differences among groups were few （P 〈 0.05）. Four hours later, those were significandy increased in group B, while those increased slowly in group A （P 〈 0.05）. ③ Comparison of the absorptance of sticking fibrinogen in two groups in different time-points after cor sinistrum assistant bypass： Absorbing contents of materials in both groups gradually increased with the increasing of bypass time, while the absorbing fibrinogen in each time-point after cor sinistrum in group A were lower than those in group B （P 〈 0.05）.④ Comparison of the absorptance of albumin in different time-points after cor sinistrum assistant bypass： The absorbing contents of materials in two groups to albumin gradually increased with the increasing of bypass time, while the absorbing albumin in each time-point after cor sinistrum assistant bypass in group A were significantly higher than those in group B （P〈 0.05）. CONCLUSION： Hard-segment modified PU has better haemocompatibility than that of pure PU, which can be spreaded and applied as the best masterial of VAD.