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汪源 周曼玲 黃飛
[摘要] 目的 探討Stanford A型主動(dòng)脈夾層中低溫停循環(huán)手術(shù)的安全溫度范圍。方法 收集2015年1月~2016年10月同濟(jì)醫(yī)院收治的Stanford A型主動(dòng)脈夾層手術(shù)患者40例,隨機(jī)分為低溫度組(鼻咽溫22~<24℃)與高溫度組(鼻咽溫24~26℃),每組各20例,在中度低溫停循環(huán)結(jié)合單側(cè)順行性腦灌注下行手術(shù)治療。觀察兩組病例的術(shù)中術(shù)后情況。 結(jié)果 低溫組體外循環(huán)時(shí)間較高溫組顯著延長(zhǎng)(P < 0.01),主動(dòng)脈阻斷時(shí)間與停循環(huán)時(shí)間兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05)。兩組間TND(短暫性神經(jīng)系統(tǒng)障礙)和PND(永久性神經(jīng)障礙)差異無統(tǒng)計(jì)學(xué)意義(P > 0.05);低溫組ICU天數(shù)較高溫組顯著延長(zhǎng)(P < 0.05);住院死亡率及住院天數(shù)兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05)。 結(jié)論 鼻咽溫24~26℃是Stanford A型主動(dòng)脈夾層中低溫停循環(huán)手術(shù)合適的安全溫度。
[關(guān)鍵詞]主動(dòng)脈夾層;中低溫停循環(huán);腦保護(hù)
[中圖分類號(hào)] R654.2 [文獻(xiàn)標(biāo)識(shí)碼] A [文章編號(hào)] 1673-7210(2017)07(a)-0059-04
[Abstract] Objective To explore the safe temperature range of the moderate hypothermic circulatory arrest surgery in Stanford type A aortic dissection. Methods From January 2015 to October 2016, in Tongji Hospital, 40 Stanford type A aortic dissection patients were divided into two groups by random number table, low temperature group (nasopharyngeal temperature 22-<24℃) and high temperature group (nasopharyngeal temperature 24-26℃), with 20 cases in each group, all patients were given surgery under moderate hypothermic circulatory arrest and Unilateral paraminic brain irrigation. The intraoperative and postoperative situation in the two groups was observed. Results The CPB time in the low temperature group was significantly more than that in the high temperature group (P < 0.01), and there was no statistically significant difference in the aortic clamping time and the arrest time between the two groups (P > 0.05). There was no significant difference in TND and PND between the two groups (P > 0.05). The ICU time in the low temperature group was significantly more than that in the high temperature group (P < 0.05). There was no significant difference in the hospitalization time and inpatient mortality between the two groups (P > 0.05). Conclusion 24-26℃ is a more safe nasopharyngeal temperature range in Stanford type A aortic dissection during moderate hypothermic circulatory arrest.
[Key words] Aortic Dissection; Moderate hypothermic circulatory arrest; Cerebral protection
Stanford A型主動(dòng)脈夾層手術(shù)關(guān)鍵在于主動(dòng)脈弓部的重建,在此過程中,停循環(huán)會(huì)造成腦部灌注急劇下降[1]。腦部血供豐富,也是最不耐受缺血缺氧的重要器官。故而,弓部重建手術(shù)中的腦保護(hù)策略至關(guān)重要,不僅關(guān)系到術(shù)后神經(jīng)系統(tǒng)并發(fā)癥的發(fā)生,也直接影響患者的術(shù)后存活率。深低溫停循環(huán)(DHCA)可保證弓部手術(shù)操作視野清晰,同時(shí)將全身代謝水平降至最低;結(jié)合保護(hù)性的腦灌注可保證腦的殘余代謝[2]。近年來,深低溫的局限性受到質(zhì)疑,中度低溫停循環(huán)(MHCA)聯(lián)合順行性腦灌注漸被接受為主流的腦保護(hù)方式[3]。但在中度低溫范圍內(nèi)具體溫度采用多少更加安全有利,卻并無統(tǒng)一意見。擬通過本研究將安全溫度范圍進(jìn)行探討。
1 資料與方法
1.1 一般資料
選擇2015年1月~2016年10月同濟(jì)醫(yī)院收治的Stanford A型主動(dòng)脈夾層手術(shù)患者40例。全部病例為男性,采用隨機(jī)數(shù)字表分為兩組,停循環(huán)鼻咽部溫度22~<24℃低溫組(20例),停循環(huán)鼻咽溫度24~26℃高溫組(20例);A組平均年齡為(56.10±8.94)歲,B組平均年齡為(51.5±9.54)歲,兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05)?;颊咧泻喜ENTAL手術(shù)7例,冠脈搭橋手術(shù)4例。本研究經(jīng)醫(yī)院醫(yī)學(xué)倫理委員會(huì)批準(zhǔn),所有患者和/或家屬均知情同意并簽署知情同意書。
納入標(biāo)準(zhǔn):①術(shù)前經(jīng)CTA檢查確診為A型主動(dòng)脈夾層;②年齡18~<65歲。排除標(biāo)準(zhǔn):①術(shù)前有中樞神經(jīng)系統(tǒng)既往病史或有明確相關(guān)陽性癥狀與體征;②術(shù)前腦部CT或MR陽性發(fā)現(xiàn)(梗死、出血或腦血管病變);③術(shù)前多普勒超聲檢查提示頸動(dòng)脈狹窄;④急診手術(shù)。
1.2 設(shè)備與材料
SORIN公司STORCERT-S5型滾壓血泵機(jī)系統(tǒng)、SC型變溫水箱;FLYING公司FAF-1動(dòng)脈端微血栓過濾器、體外循環(huán)插管及管道套裝;Casmed公司紅外腦氧飽和度監(jiān)測(cè)系統(tǒng)。
1.3 手術(shù)及體外循環(huán)方法
行常規(guī)氣管插管全身麻醉,術(shù)中監(jiān)測(cè)心電、有創(chuàng)連續(xù)動(dòng)脈血壓、腦氧飽和度監(jiān)測(cè)、連續(xù)血?dú)夥治黾盎罨獣r(shí)間(ACT)水平。分離顯露右腋動(dòng)脈,并行動(dòng)脈插管;正中劈開胸骨開胸,于右房置入腔房管建立體外循環(huán)。咽溫降至33℃后,阻斷主動(dòng)脈后并切斷升主動(dòng)脈,分別于兩側(cè)冠脈開口處直視灌注1∶4冷含血心肌停博液(負(fù)荷總量15 mL/kg,每30分鐘半量重復(fù))。升主動(dòng)脈近端處理完畢后,進(jìn)入中低溫停循環(huán)(低溫組:22~<24℃,高溫組:24~26℃),同時(shí)以右側(cè)腋動(dòng)脈進(jìn)行單側(cè)選擇性腦灌注[灌注流量5~8 mL/(kg·min)],在清晰視野下完成弓部重建。
1.4 統(tǒng)計(jì)學(xué)方法
采用統(tǒng)計(jì)軟件SPSS 17.0對(duì)數(shù)據(jù)進(jìn)行分析,正態(tài)分布的計(jì)量資料以均數(shù)±標(biāo)準(zhǔn)差(x±s)表示,兩組間比較采用t檢驗(yàn);計(jì)數(shù)資料以率表示,采用χ2檢驗(yàn)。以P < 0.05為差異有統(tǒng)計(jì)學(xué)意義。
2 結(jié)果
2.1 術(shù)中情況
低溫組體外循環(huán)時(shí)間較高溫組顯著延長(zhǎng),主動(dòng)脈阻斷時(shí)間與停循環(huán)時(shí)間兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05)。見表1。
2.2 術(shù)后結(jié)果
術(shù)后腦保護(hù)效果的觀察指標(biāo)短暫神經(jīng)障礙(TND)和永久性神經(jīng)障礙(PND)比較,兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05);低溫組ICU天數(shù)較高溫組顯著延長(zhǎng),差異有統(tǒng)計(jì)學(xué)意義(P < 0.05);住院死亡率及住院天數(shù)兩組差異無統(tǒng)計(jì)學(xué)意義(P > 0.05)。見表2。
3 討論
Stanford A型主動(dòng)脈夾層是一種極為兇險(xiǎn)的心血管疾病,致死致殘率極高,體外循環(huán)下的主動(dòng)脈弓部重建術(shù)是有效的治療手段。弓部重建階段的腦血流量改變也是此手術(shù)風(fēng)險(xiǎn)的重要因素,腦部對(duì)缺血缺氧的敏感性無需多言,如何在此過程中合理腦保護(hù)異常重要[4-5]。
低溫可以降低組織代謝率,從而讓機(jī)體安全度過缺血缺氧階段,是一項(xiàng)重要的腦保護(hù)策略。從1978年首例弓部重建手術(shù)開始,深低溫停循環(huán)被作為弓部手術(shù)室的標(biāo)準(zhǔn)腦保護(hù)手段[6-7]。但隨著相關(guān)臨床實(shí)踐經(jīng)驗(yàn)的積累和實(shí)驗(yàn)研究進(jìn)展,過低溫度的負(fù)面影響逐步被認(rèn)識(shí),特別是其對(duì)于凝血機(jī)制的破壞作用[8]。同時(shí)腦的選擇性灌注技術(shù)也日趨成熟,最初的逆行還是順行的爭(zhēng)論已有結(jié)果,單側(cè)或雙側(cè)順行選擇性腦灌注被證實(shí)能較好的滿足低代謝狀態(tài)下的腦部氧耗與營(yíng)養(yǎng)供應(yīng),從而也使對(duì)深低溫的要求降低[9-10]。目前,雖然還存在一定爭(zhēng)論,但國(guó)內(nèi)外主流心臟中心現(xiàn)多選用中度低溫(鼻咽部溫度22~28℃)聯(lián)合選擇性腦灌注作為腦保護(hù)手段[11-12]。但針對(duì)于中度低溫較寬的范圍內(nèi),較少有相關(guān)研究對(duì)具體溫度段的安全性進(jìn)行對(duì)照分析;因此,很多中心仍保守的選擇趨近于深低溫的22~24℃[13-16]。本研究擬通過前瞻性的隨機(jī)對(duì)照臨床試驗(yàn),分析不同溫度段的腦保護(hù)效果。
TND與PND是術(shù)后監(jiān)測(cè)腦保護(hù)效果的最為直接的觀察指征[17]。本研究中高溫度組(鼻咽溫24~26℃)與低溫度組(鼻咽溫22~<24℃)的TND與PND無統(tǒng)計(jì)學(xué)意義差異(P > 0.05),這也直接表明在兩個(gè)溫度段的腦保護(hù)效果無差異。而兩組間的住院死亡率也無差異,也進(jìn)一步證實(shí)里這一點(diǎn),同時(shí)也提示兩溫度段的安全性同樣無差異。
如何在兩組間選擇合適的溫度范圍是本研究的主要目的。本研究結(jié)果表明:高溫度組的體外循環(huán)時(shí)間顯著短于低溫度組(P < 0.01),而二者的停循環(huán)時(shí)間及主動(dòng)脈阻斷時(shí)間卻無統(tǒng)計(jì)學(xué)意義差異(P > 0.05),這提示手術(shù)操作上的困難程度不是兩組間體外循環(huán)時(shí)間差異的原因。升溫時(shí)間過長(zhǎng)或是低溫組的體外循環(huán)時(shí)間延長(zhǎng)的主要原因。而體外循環(huán)過程所造成的血液成分的破壞、炎性因子的生成及全身的炎性反應(yīng)均隨體外循環(huán)時(shí)間延長(zhǎng)而加重[18]。Stamou等[19]的研究表明體外循環(huán)時(shí)間大于200 min是影響患者死亡率的獨(dú)立危險(xiǎn)因子。本研究中,低溫組患者的ICU時(shí)間較高溫組顯著延長(zhǎng),這可能與延長(zhǎng)的體外循環(huán)時(shí)間相關(guān)。過長(zhǎng)的體外循環(huán)時(shí)間會(huì)加劇術(shù)后患者炎癥因子介導(dǎo)的肺損傷,從而使術(shù)后呼吸機(jī)支持時(shí)間延長(zhǎng),這已被臨床實(shí)踐及實(shí)驗(yàn)研究所證實(shí)[20]。除了長(zhǎng)時(shí)間體外循環(huán)對(duì)血液成分的破壞外,過低溫度本身對(duì)于機(jī)體凝血機(jī)制的損害也早被證實(shí),術(shù)后的胸腔引流增多也是患者恢復(fù)時(shí)間延長(zhǎng)的重要原因。
本研究結(jié)果提示,中度低溫高溫度段與低溫度段具有同等的腦保護(hù)安全性。而高溫度段不僅在停循環(huán)階段可有效保護(hù)腦部機(jī)能,較高的溫度也可縮短升溫時(shí)間,減小體外循環(huán)操作難度;更能減少過低溫度和延長(zhǎng)體外循環(huán)時(shí)間對(duì)患者的傷害,縮短恢復(fù)時(shí)間。據(jù)此研究結(jié)果,推薦在Stanford A型主動(dòng)脈夾層手術(shù)中選擇鼻咽溫度24~26℃停循環(huán)配合單側(cè)順行性腦灌注作為腦保護(hù)策略。
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(收稿日期:2017-04-08 本文編輯:蘇 暢)