彩色多普勒超声心动图检测牛颈静脉带瓣管道重建犬右室流出道后结构及血流动力学研究

Structural and hemodynamic study of right ventricular outflow tract reconstruction with valved bovine jugular vein conduit in the canine model by color Doppler echocardiography

目的:采用彩色多普勒超声心动图(echocardiography,UCG)观察牛颈静脉带瓣管道重建犬右室流出道(right ventricular outflow tract,RVOT)后心血管结构和血流动力学变化。方法:应用牛颈静脉带瓣管道(valved bovine jugular vein conduit,BJVC)重建犬右室流出道,分三阶段,共32只实验犬。应用UCG在术后、术后7d和1年后观察右心室与肺动脉结构状况,测定重建后BJVC各截面的直径、右心室和肺动脉端吻合口的宽度、血流速度(V)和压差(pressure gradient,PG),并评价BJVC通畅情况。结果:第一阶段,5只犬术后彩色多普勒超声心动图检测犬右心室与BJVC重建的右室流出道(right ventricularoutflow tract,RVOT)吻合口部分存在的压差稍大,吻合口普遍偏小;部分犬BJVC远端与肺动脉主干吻合处表现出吻合口偏小,血流经过流速加快,压差增高,彩色多普勒血流呈五彩镶嵌。第二阶段,重建术后1年7只犬均存活,术后UCG检查瓣膜关闭良好,无明显返流,跨瓣压差小;带瓣管道通畅,未见血栓形成图像,除1只犬瓣叶活动稍差外,其余犬瓣叶活动良好。第三阶段,共观察20例,术后、术后7d和1年UCG检测示带瓣管道通畅,瓣膜关闭良好,右室与BJVC吻合口及远端吻合口通畅,周边无渗漏,无明显返流或湍流图像,跨瓣压差小,未见明显新生物图像。结论:UCG能定性、定量观察和评价BJVC重建犬RVOT的结构和血流动力学变化,可以正确评价其术后疗效,对BJVC的研制和临床应用具有重要价值。

Objective To observate the structural and hemodynamic changes after the reconstruction of right ventricular outflow tract （RVOT） with valved bovine jugular vein conduit （ BJVC ） in the canine model by color Doppler echocardiography （UCG）. Methods BJVC was used in the reconstruction of RVOT of 32 canines. UCG was used to observe the structure of the right ventricle and RVOT. The structure and hemodynamics were observed, and the diameter, width, blood velocity and pressure gradient （PG） were measured between the right ventricle and the conduits. Results In the first stage, UCG showed that PG between the right ventricle and BJVC was high in 5 canines, and a few anastomosis in BJVCs with main pulmonary artery was small. Blood velocity quickened and PG increased, and color Doppler showed that the bloodstream was very bright. In the second stage, 7 canines survived for 1 year after the implantation. One year after the operation, UCG showed that the valve closed well, no graft kinking or obvious regurgitation of the valve was observed. The PG of the valve was low. The BJVCs were unobstructed and there was no thrombus. All the valves of BJVC opened well except one. In the third stage, 20 canines survived for 1 year after the implantation. UCG showed that the valve motion was good, no graft kinking or obvious regurgitation of the valve was observed. No neoplasm was observed. Conclusion UCG is one of the most useful measurements in the structural and hemodynamic study of RVOT reconstruction by BJVC in the canine model. The good evaluation of UCG implies that it is important for the study and clinical pratice.