【作者】 王锋；

【导师】 易定华；

【作者基本信息】 第四军医大学 ， 外科学， 2013， 博士

【摘要】 目的：探讨不同性别和升主动脉瘤大小对主动脉重构与临床特点的影响以及预后分析,分析出不同的风险预测模型对升主动脉瘤术后的预后影响。方法：分别选取我院2006年2月至2013年2月167例升主动脉瘤患者，并选取180例单纯行冠状动脉搭桥手术患者作为对照组，依据主动脉瘤直径大小分为四个亚组，直径小于4cm（n=61），直径4-5cm(n=29)，直径5-6cm(n=51)和直径大于6cm(n=26)。术中经食道超声心动图测量升主动脉瘤最大部位的一个完整剖面的4个特定数据：主动脉直径（收缩和舒张）和主动脉壁的厚度（收缩和舒张），进一步计算出：主动脉壁膨胀性(Dist)，主动脉壁应力(WS)和增量弹性模量(Einc)。升主动脉瘤直径<5cm组（n=90），5-6cm组和>6cm组患者，术前应用超声心动图观察明确诊断和相关并发症，并对大于5cm组术中和围术期临床资料随访0-24个月进行观察统计；分别于术后4h,8h,12h,24h采血测定心肌酶（CK-MB)变化。对直径5-6cm和6>cm升主动脉瘤术后根据查尔森指数评分，EuroSCORE，DASI和MSSS方法进行危险因素和预后评估。结果：性别差异和直径大小与升主动脉瘤力学重构：升主动脉瘤组及其4个亚组和对照组的平均收缩期末的主动脉直径，与舒张期末同性组相比明显缩小，均具有统计学意义（P<0.05）。和对照组男性患者在升主动脉瘤组比女性患者明显扩大（P<0.05）。升主动脉瘤组及其4个亚组和对照组的平均收缩期末和舒张期末的主动脉壁厚度，与同组女性患者相比均无统计学意义（P>0.05），但5-6cm组的平均收缩期末和舒张期末的主动脉壁厚度比对照组、<4cm组、4-5cm组均明显变薄（P<0.05），>6cm组比5-6cm组更薄（P<0.05）。主动脉壁膨胀性（Dist）在男性和女性之间明显下降，具有统计学意义（P<0.05），<4cm组、4-5cm组与对照组组间均无显著差异（P>0.05），而5-6cm组的主动脉壁膨胀性比其他组明显减少（P<0.05），>6cm组比5-6cm组更加明显减小（P<0.05）。升主动脉瘤组与对照组男性女性主动脉壁应力明显增加，具有统计学意义（P<0.05），随着升主动脉瘤直径的增加，主动脉壁应力也逐渐增加，升主动脉瘤4个亚组与对照组相比，具有统计学意义（P<0.05），组间比较仅在>6cm组男女性别差异明显，具有统计学意义（P<0.05）。升主动脉瘤组比对照组的增量弹性模量相比，明显增加，具有统计学意义（P<0.05），随着升主动脉瘤直径的增加，增量弹性模量明显增加，均具有统计学意义（P<0.05）。表明随着升主动脉瘤直径的增加，男女的主动脉壁膨胀性（Dist）也逐渐下降，对照组与升主动脉瘤组的Dist男女差异不明显（P>0.05），而在男性，Dist下降与主动脉瘤直径大小有很高的相关性（r2=0.28p<0.05，n=167），在女性没有相关性。表明随着主动脉瘤直径的增加，男女的升主动脉壁Einc也逐渐增加，而在男性和女性，升主动脉壁Einc逐渐增加与主动脉瘤直径大小有很高的相关性（r2=0.29/0.24p<0.05，n=167）。性别差异和主动脉瘤直径大小与临床病变特点分析：术前超声心动图检查结果，升主动脉瘤诊断完全符合，与心血管造影一致，其中90例<5cm组无心包积血/液，而5-6cm组心包积血/液有11.8%，明显增多，>6cm组30.8%更加增多（p<0.05），<5cm组均未发现主动脉夹层和内膜破口，而在5-6cm组和>6cm组增加明显（p<0.05）。升主动脉瘤术后各时间点CK-MB的变化存在性别差异，女性与男性相比，女性显著高于男性，(P<0.05)；与男性相比较，女性更易发生POAF(P<0.05)；术后输血的概率，女性与男性相比，具有显著差异(P<0.05)；而男性肾衰的发生概率具有显著差异；男女在切口感染发生率、平均通气时间、住院时间、总并发症概率和住院死亡率存在性别差异，女性显著高于男性，具有较高的发生率(P<0.05)。女性与住院时间的延长，伴随着CK-MB水平的上升(P<0.05，r2=0.52)；随主动脉阻断时间和ICU滞留时间的延长，CK-MB水平的也不断上升(P<0.05）。性别差异和升主动脉直径大小对升主动脉瘤预后的影响：没有调整的男女总的住院死亡分别是2.6%和5.1%，在单因素分析中存在显著差异（P<0.001）,但在多因素分析中却不存在显著差异(P=0.762)；多因素预测患者12月内和12-24月死亡率，女性并不是独立的高危因素（P=0.632，0.091），通过性别调整后，与男性相比较，女性更易发生中风、房颤和疼痛，同时输血、住院时间长和总并发症发生率高的风险性也相应增加。查尔森指数评分，EuroSCORE男女相比较具有显著性差异，女性得分较高，说明女性预后较差；但DASI对心血管生理功能的预测，女性得分较高，说明与男性相比，女性术后生理功能预后较好，具有显著性差异。在MSSS评估术后身心健康方面，男性术后身心健康状况要好于女性。24个月生存率女性与男性相比，女性明显降低，通过女性调整后的资料表明，生存率与女性并不是相关联（P=0.091)。结论：1.升主动脉重构及其力学特性存在性别差异，与男性相比，女性有较小的主动脉直径，但有较低的应力，>5cm时具有较高的主动脉壁膨胀性（Dist）。2.升主动脉瘤直径>5cm时，以几何学形态改变为主，血管呈扩张状态，管壁厚度变薄，>6cm时主动脉壁厚更加明显变薄，形成夹层或破裂的急性血管事件概率将快速上升。3.直径>5cm的升主动脉瘤，主动脉膨胀性明显降低，应力明显增高，增量弹性模量明显降低，尤其>6cm变化更明显，其血管壁易碎性和易损伤性明显增加。4.升主动脉瘤术前超声心动图检查结果显示，直径>5cm出现心包积血/液，主动脉内膜破口和主动脉夹层明显增多，提示>5cm升主动脉瘤应积极进行手术治疗。5.升主动脉瘤女性患者比男性更易发生POAF,切口感染、平均通气时间、住院时间、总并发症概率和住院死亡率明显增多，提示女性升主动脉瘤手术风险高，要加强监护和治疗。6.查尔森指数评分对男女升主动脉瘤相比较具有显著性差异，女性得分较高，说明女性术后预后较差，同时增加了住院时间，相应增加了术后并发症发生的概率较大。EuroSCORE女性得分较高，也说明女性比男性升主动脉瘤术后风险性较高，预后差。DASI对心血管生理功能的预测，女性得分较高，说明与男性相比，女性术后心血管生理功能预后较好。MSSS评估术后身心健康方面，男性分值较低，说明男性术后身心健康状况要好于女性。更多还原

【Abstract】 Objective: To evaluate the effect of the remodeling and clinical characteristics of theaorta as related to size of ascending aortic aneurysm and sex. To analyse the effect of sexand size difference in predicting the postoperative outcome by different risk-model-evaluated scoring system. Methods: Between2006and2013, the mechanicalcharacteristics of the aorta were measured by transesophageal echocardiography(TEE) atthe time of surgery in167patients with ascending aortic aneurysm undergoing selectivesurgery and in180control patients with normal aortas undergoing coronary artery bypass grafting. According to size,four subgroups were divided. Four parameters were measuredin all patients: aortic diameter in end-systole and end-diastole, and aortic wall thickness inend-systole and end-diastole. These were used to calculate mechanical characteristics ofthe aorta from standard equations. Aortic distensibility reflects the elastic qualities of theaorta. Aortic wall stress reflects the disrupting force experienced within the aortic wall.Incremental elastic modulus indicates loss of elasticity reserve.Clinical characteristics ofthe aortic aneurysm and sex difference were gathered including the pre-,peri-andpost-operative data were measured in4h,8h,12h and24h respectively.Postoperative peakcreatine kinase MB levels scoring systems were used to evaluate the prognostic effect insize-specific aortic aneurysm and sex.24months follow-ups were carried out aftersurgery.Results: Compared with the control group, mean end-systolic in aneurysmalgroups and end-diastolic diameter in same sex-group were shorted significantly,whilemore enlarged in men than in women.（P<0.05）.Compared with women in samesex-groups,there were significantly differences with respect to the size of meanend-systolic and end-diastolic wall thickness （P>0.05）.However,mean end-systolic andend-diastolic wall thickness in5-6cm subgroup was significantly thinner than in thecontrol group,<4cm subgroup and4-5cm subgroup,especially thinnest when comparingbetween5-6cm and>6cm subgroup.There were significantly differences between womenand men according to the mechanical characteristics of aortic distensibility（P<0.05）,while no difference in <4cm and4-5cm subgroup compared with the controlgroup（P>0.05）.Aortic distensibility was obviously decreased in5-6cm subgroupcompared with other groups,especially in>6cm subgroup.（P<0.05）.With the increase inaortic diameter, there were obviously differences between the control and aneurysmalgroups according to the mechanical characteristics of wall stress（92.51/90.51VS157.8/149.9） and incremental elastic modulus （1.18/1.16VS1.93/1.87）.andfurthermore,wall stress had sex difference in>6cm subgroup （P<0.05）.There werestrikingly differences between the control and aneurysmal groups in accordance withincremental elastic modulus（.P<0.05）.Ahigh correlation between aortic distensibility andthe increase in aortic diameter was found in men （r2=0.28p<0.05,n=167）, while no correlation in women.Similarly,a high correlation between incremental elastic modulusand the increase in aortic diameter was found in men and in women respectively（r2=0.29/0.24p<0.05,n=167).Hemopericardium according to the preoperative outcome of Doppler ultrasonicechocardiography(UCG) was obviously increased in5-6cm and>6cm grouprespectively,compared with <5cm group.There were significantly differences in5-6cmand>6cm group on clinical characteristics of aortic dissection and intima crevasse,whilenot seen in <5cm group.There were significantly sex differences on morbidity in different-sizedascending aortic aneurysm in5-6cm and>6cm subgroup respectively （p<0.05）.Therewere also sex differences in the peak CK-MB level of different time points. women issignificantly higher than men（p<0.05）.Ahigh correlation between the length of CPB andICU stay and hospital stay with the increase in level of CK-MB was found.Similarly，therewere correlation between the length of hospital stay and the increase in level ofCK-MB.Compared with men,the early postoperative outcome and complication, such asnew-set POAF,lesion infection, in-hospital mortality and the length of hospital stay, wererelatively higher in women.The unadjusted in-hospital mortality rate was2.6%in men and5.1%in women.This difference was significant on univariate analysi（sP<0.001）but not onmultivariate analysis（P=0.762）.After adjusting for difference in patient variables,femalesex was not independently associated with long-tern surviva（lP=0.632，0.091）. Accordingto risk scores of Charlson index and EuroSCORE, women’s prognosis was poorer thanmen,while better in DASI. In terms of MSSS assessment on postoperative physical andmental health, men were better than women.After adjusting sex difference,24monthssurvival rate were decreased obviously in women.Conclusion: There may also be sexdifferences in the remodeling and biomechanical characteristics of the aorta with anincrease in aortic diameter.We may accurately predict and calculate the biomechanicalcharacteristics of the aorta by transesophageal echocardiography. Such assessmentshould lead to increased safety of our patients who were at risk of rupture or dissection,onthe basis of accessible and reproducible biomechanical data.Woman was not independent risky factors.Differences in gender and aortic diameter size was likely to be risk factors ofclinical features.Clinical characteristics were urgent and progressive in women.Differentrisk evaluating system showed that women had a higher mortality rate and poorer outcomethan men.更多还原