对比增强超声心动图对拟肝移植患者肺内分流的评估价值

背景：晚期肝病患者的肺内血管异常可以导致肺内右向左分流及严重低氧血症，目前国内对筛查肺内血管扩张尚缺乏一种简便、敏感、有效的方法。 目的：评估对比增强超声心动图对晚期肝病肺内分流的临床诊断价值。 设计、时间及地点：前瞻性病例对比观察，于2004-02／2006-02在解放军第四五八医院肝病中心完成。 对象：解放军第四五八医院肝病中心收治的男性拟行肝移植的晚期肝病患者24例。 方法：在无任何血管扩张药治疗情况下例行常规检查。采用对比增强超声心动图筛查晚期肝病患者肺内右向左分流的发生率，并根据左心室微泡的显示程度半定量分析记录为1^＋～3^＋。将患者分为经超声心动图证实有肺内分流组和无肺内分流组。 主要观察指标：拟行肝移植的晚期肝病患者肺内右向左分流的发生率及临床特点。结果：①24例患者中10例（41．7％）经对比增强超声心动图证实肺内右向左分流，左心室显影异常程度1^＋～2^＋，其中6例1^＋，4例2^＋，出现在右心室显影后6～10余个心动周期。②两组患者的年龄、性别、动脉血气分析指标、肝功能指标差异无显著性意义（P〉0．05）。③经超声心动图证实肺内分流组患者的上消化道出血发生率、门脉高压指征脾脏厚度及右心功能参数肺动脉收缩压、Tei指数均高于无肺内分流组（P〈0．05～0．01）。 结论：晚期肝病合并肺内分流而无低氧血症时肺血管扩张比较常见，对比增强超声心动图为诊断肺内血管扩张提供了一种敏感、非创伤的早期检查手段。门脉高压症是发生肺内血管扩张的主要因素，右心室Tei指数可作为评估肺内血管扩张患者右心功能的重要参数。

Assessment on intrapulmonary shunting in liver transplantation candidates using contrast-enhanced echocardiography

BACKGROUND: Intrapulmonary vascular abnormalities result in the right-to-left shunting and severe hypoxemia in liver transplantation candidates. Currently, a convenient, sensitive and effective method is absent to screen the intrapulmonary vascular dilatations.OBJECTIVE: To evaluate the role of contrast-enhanced echocardiography on clinical diagnosis of intrapulmonary shunting in liver transplantation candidates.DESIGN, TIME AND SETTING: The experiment, prospective controlled observation based on cases, was performed at the Hepatology Unit of the 458 Hospital of PLA (Guangzhou, Guangdong, China) from February 2004 to February 2006.PARTICIPANTS: Twenty-four consecutive liver transplantation candidates were recruited from the Hepatology Unit of the 458Hospital of PLA.METHODS: Routine examination was conducted under the condition without any regimen of vascular dilatation drugs.Contrast-enhanced echocardiography was applied to detect the prevalence of right-to-left shunting in the patients with end-stage liver disease. The microvesicle of the left ventricle in patients was qualitatively assessed by a score from 1+ to 3+. Accordingly, all patients were divided into two groups: intrapulmonary shunting and non-intrapulmonary shunting.MAIN OUTCOME MEASURES: The prevalence of right-to-left shunting and clinical characteristics of liver transplantation candidates were determined.RESULTS: Ten (41.7%) of 24 patients with positive contrast-enhanced echocardiography were proved to develop the intrapulmonary right-to-left shunting, including 6 for l+ and 4 for 2+ by left ventricle abnormality, which emerged after 6-10 cardiac cycles of right ventricle abnormality. There were no significant differences in age, gender, arterial blood gas analysis and liver function tests between the two groups (P > 0.05). Echocardiography results demonstrated that, the upper digestive tract hemorrhage,spleen thickness that indicated portal hypertension, pulmonary artery systolic pressure and Tei index were significandy higher in the patients of intrapulmonary shunting than in those of non-intrapulmonary shunting (P<0.05-0.01 ).CONCLUSION: Intrapulmonary vascular dilatation occurs frequently in liver transplantation candidates associated with intrapulmonary shunting but without hypoxemia. Contrast-enhanced echocardiography is a sensitive and non-invasive method for the early diagnosis of intrapulmonary vascular dilatation. The pathogenic cause is portal hypertension. Tel index can be used as an important parameter for evaluating right ventricular function in patients of intrapulmonary vascular dilatation.