脊髓缺血損傷動(dòng)物模型的建立

1、脊髓缺血損傷動(dòng)物模型的建立 作者：管玉龍，劉鋒，董培青，萬(wàn)彩紅，楊璟 【摘要】 目的本研究擬建立胸降主動(dòng)脈手術(shù)脊髓缺血?jiǎng)游锬Ｐ?，為脊髓保護(hù)策略和藥物干預(yù)研究提供基礎(chǔ)。方法實(shí)驗(yàn)中采用6只北京農(nóng)大小型豬。經(jīng)左側(cè)第五肋間開(kāi)胸，常溫條件下在鎖骨下動(dòng)脈以遠(yuǎn)阻斷降主動(dòng)脈，30min后阻斷開(kāi)放。動(dòng)物復(fù)蘇后，對(duì)其下肢行為學(xué)臨床評(píng)分每日進(jìn)行觀察。7日后處死動(dòng)物取材，進(jìn)行損傷區(qū)域脊髓超微結(jié)構(gòu)觀察。結(jié)果術(shù)中血液動(dòng)力學(xué)平穩(wěn)。血?dú)饨Y(jié)果均維持在正常范圍。復(fù)蘇后1只動(dòng)物術(shù)后每天肌力均為IV 級(jí)，7天后處死時(shí)肌力IVV級(jí)；其余5只動(dòng)物術(shù)后下肢肌力0 I級(jí)。電子顯微鏡超微結(jié)構(gòu)觀察顯示脊髓較嚴(yán)重的損傷性改變。結(jié)論應(yīng)用小型豬為動(dòng)物

2、模型，在常溫條件下胸降主動(dòng)脈阻斷30min，可以建立急性脊髓缺血術(shù)后截癱模型。 【關(guān)鍵詞】 脊髓；缺血；胸主動(dòng)脈The Establishment of Porcine Model of Spinal Cord Ischemic InjuryAbstract: OBJECTIVE This study was designed to establish a porcine model of spinal cord ischemic injury produced by descending thoracic aorta occlusion and provide basis for strat

3、egy of spinal protection and pharmaceutical intervention. METHODSSix piglets were used in the experiments supplied by the Beijing College of Agriculture. A standard left thoracotomy was made through the fifth intercostals space. The descending aorta was clamped distal to left subclavian artery at no

4、rmothermia. Thirty minutes later, the clamps were released. The trachea was extubated once the animals recovered breathing spontaneously. The animals were evaluated daily according to a quantitative behavioral score. On postoperative seventh day the animals were sacrificed and histological analysis

5、for the injury of spinal cord was made. RESULTSHemodynamic data showed all animals were stable before, during and after the procedure. The results of behavioral scoring for each animal demonstrated one animal with paraparesis and other 5 animals with paraplegia. The injury of spinal cord was also de

6、monstrated by ultrastructural measurement.CONCLUSIONA porcine model of spinal cord ischemic injury can be established by descending thoracic aortic clamping thirty minutes at normothermia.Key words：Spinal cord；Ischemia；Thoracic aorta胸主動(dòng)脈疾病實(shí)施外科治療期間，圍術(shù)期多種因素可能引起脊髓缺血，術(shù)后脊髓并發(fā)癥一旦發(fā)生，直接影響手術(shù)效果和患者的生存質(zhì)量。根據(jù)文獻(xiàn)報(bào)告，

7、多以單純阻斷降主動(dòng)脈30min為臨床界定的安全時(shí)限。本研究對(duì)實(shí)驗(yàn)動(dòng)物進(jìn)行胸降主動(dòng)脈阻斷30min后隨訪觀察，建立了脊髓缺血?jiǎng)游锬Ｐ?，可為進(jìn)一步的脊髓保護(hù)策略和藥物干預(yù)提供基礎(chǔ)。1材料與方法1.1實(shí)驗(yàn)動(dòng)物6只北京農(nóng)大小型豬，體重20 kg25.9 kg，雌性，在實(shí)驗(yàn)前12 h禁食，4 h禁水。1.2麻醉基礎(chǔ)1.3手術(shù)方法動(dòng)物右側(cè)臥位，經(jīng)肩胛骨下方第五肋間隙橫行皮膚切口，切口長(zhǎng)度約15cm。逐層切開(kāi)皮下組織，暴露胸腔。探查降主動(dòng)脈的部位，并仔細(xì)分離鎖骨下動(dòng)脈以遠(yuǎn)0.5cm1cm區(qū)域降主動(dòng)脈外膜，4.0手術(shù)線縫置荷包，分離其下方遠(yuǎn)心端0.5cm區(qū)域降主動(dòng)脈，套阻斷帶作為第一阻斷平面。在降主動(dòng)脈第一阻

8、斷平面部位以遠(yuǎn)4cm5cm 處進(jìn)行第二處分離，同樣套阻斷帶和縫置荷包，作為第二阻斷平面。在第一荷包和第二荷包分別插套管針，連接三通，進(jìn)行壓力測(cè)定和取血。待第一、第二阻斷平面阻斷帶放置完成后，體內(nèi)給肝素150IU/kg。首先在第一阻斷平面使用阻斷鉗阻斷降主動(dòng)脈血流，阻斷期間密切觀察血壓變化，必要時(shí)給予一定的擴(kuò)血管藥物。繼續(xù)使用第二把阻斷鉗阻斷第二平面降主動(dòng)脈血流（見(jiàn)圖1）。阻斷30min后開(kāi)放阻斷鉗，順序是先開(kāi)放遠(yuǎn)心端阻斷鉗，后開(kāi)放近心端阻斷鉗。魚(yú)精蛋白中和體內(nèi)肝素（比例11）。1.4監(jiān)測(cè)指標(biāo)2結(jié)果2.1血液動(dòng)力學(xué)術(shù)中血液動(dòng)力學(xué)平穩(wěn)，阻斷前血壓維持在100120 mm Hg，心率120140次/min。在阻斷后近心端血壓明顯上升，心率先加快后減慢，給予藥物降壓處理維持在90100次/min。遠(yuǎn)心端血壓20 mm Hg。開(kāi)放后血壓較術(shù)前有一定的下降，但沒(méi)有統(tǒng)計(jì)學(xué)意義。2.2血細(xì)胞手術(shù)期間動(dòng)物血細(xì)胞壓積和血色素輕度下降，7天后處死時(shí)基本恢復(fù)正常。2.3溫度手術(shù)期間肛溫變化不明顯，術(shù)前為36.537，阻斷期間肛溫35.536，手術(shù)結(jié)束時(shí)肛溫3636.5。2.4下肢行為學(xué)動(dòng)物術(shù)前上下肢肌力均為V級(jí)，阻斷30 min術(shù)后動(dòng)物順利清醒拔除氣管插管，上肢肌力恢復(fù)