血管内超声对小儿高肺血流性肺高压肺血管病理变化的评价

Evaluation of pulmonary pathologic process in children with pulmonary hypertension and congenital heart defects by intravascular ultrasound

目的 :探讨应用血管内超声 (IVUS)评价小儿高肺血流性肺动脉高压 (PAH)肺血管病理变化的可行性。方法 :对 19例高肺血流性PAH患儿及 6例肺动脉压力正常的对照病例行右心导管及右下肺后段肺动脉IVUS检查。其中 15例PAH行右下肺叶后段肺组织活检。观察各病例IVUS图像的特点。将IVUS参数与部分病例肺活检病理结果进行对照研究。结果 :肺动脉压力正常者 2～ 4mm内径的肺段动脉IVUS表现为单层回声 ,PAH者多数表现为同心性层状回声 ;不同病理改变的患儿IVUS图像有所不同。结论 :IVUS能够反映高肺血流性PAH肺血管的病理变化 。

Objective:To define the intravascular ultrasonic (IVUS) characteristics of pulmonary vasculature in children with pulmonary hypertension(PAH) caused by left to right shunt congenital heart defects, and to assess the feasibility of IVUS in evaluating the pulmonary pathologic changes of PAH.Methods:IVUS imagings were underwent in 19 children with PAH and 6 children with normal pulmonary artery pressure. 30 MHz/ 2.9 F IVUS catheters were placed in right inferior pulmonary arteries with an internal diameter of 2～4 mm. The thickness of middle layer and inner layer were measured if pulmonary vessel wall showed 3 layered appearance in IVUS images. Lung biopsys were performed at the corresponding sites of the distal lung tissue after IVUS studies in 15 children with PAH. The relationship between IVUS findings and Heath Edwards grade of PAH was investigated. Results:The pulmonary artery wall echo consisted of a single layer in patients with normal pulmonary pressure. While echo dense inner layer, echolucent zone, and echo dense outer layer are evident in 17 children with PAH. The IVUS characters of PAH patients with or severer than Heath Edwards grade Ⅲ was different from those with Heath Edwards grade Ⅰ and Ⅱ. The middle layer with Heath Edwards gradeⅠwas thinner than that in other PAH children. Conclusion:IVUS images could reflect the pulmonary pathologic changes in children with PAH. IVUS might has a utility in evaluating the severity degree of PAH in patients with CHD.