超声造影在增强原位肝移植后肝脏血管显像中的作用

目的　评价超声造影与彩色多普勒在观察原位肝移植后供肝血管血供情况中的作用。方法　分析了原位肝移植后的 4 7例患者 ,在注射利声显造影剂前后 ,用彩色多普勒分别观察肝脏血管的血供情况 ,并按供肝血管的血供情况进行评分等级分析 ,评分根据彩色多普勒检测血流信号的多少分 0～ 4级。结果　门静脉的血供情况在使用利声显造影前后无明显变化。肝动脉在使用利声显造影剂前 ,4 7例患者中彩色多普勒只检测到 39例患者的血流信号。应用造影剂后 ,4 6例患者的肝动脉均检测到血流信号 ;另 1例患者的肝动脉未检测到血流信号 ,后经血管造影确诊为…     

大鼠"二袖套"法双重灌注全血供肝移植模型的建立

目的：建立一个供肝灌注良好受体无肝期明显缩短及移植肝全血供稳定的肝移植动物模型。方法：“二袖套”法在Kamada吻合血管基础上改良,供肝分别经腹主动脉和门静脉双重全肝脏灌注;受体肝脏分步切除,肝上下腔静脉采用缝合法吻合,门静脉和肝下下腔静脉分别用袖套法吻合。移植肝脏动脉重建采用单纯血管套入式吻合或血管缝合的方法,胆总管采用单管内支架胆管端端吻合法。结果：共施行全血供大鼠原位肝脏移植76例（不包括预试验）,手术成功率93．406,1周存活率86．8％。结论：娴熟的显微外科技术、有效改良措施和注重手术细节是手术成功的保障,良好的灌注、受体无肝期的缩短及重建移植肝脏动脉血供能有效提高动物模型的稳定性。     

彩色及频谱多普勒超声在检查肝移植术后微血管的应用

目的 采用彩色及频谱多普勒超声检查肝脏移植术后的移植肝脏，探讨对术后早期血管并发症诊断的临床价值。方法对我院的7例肝移植、l例肝肾联合移植手术的患者术后进行二维及多普勒超声检查，观察移植患者肝实质和胆管声像图改变，并着重观察肝脏动静脉血流情况，必要时对术后的胸腹水的处理及肝脏活检提供必要的引导及监测。结果对8例术后的移植肝脏进行了为期三个月的检查随访，发现布加综合征1例，未发现肝动脉、门静脉血栓等其他并发症。结论彩色及频谱多普勒超声检查对肝移植术后早期的血管并发症的诊断有重要的临床意义。     

肝动脉/门静脉早期复流对肝移植大鼠小肠缺血再灌注损伤的影响

背景:当肝动脉与门静脉早期复流时序不同时,是否会加重对肝移植大鼠小肠缺血/再灌注的损伤尚未见大量报道。目的:探讨肝动脉与门静脉早期复流对肝移植大鼠小肠缺血/再灌注损伤的影响。方法:采用门静脉灌注的大鼠自体肝移植模型,78只SD大鼠以简单随机化法分为3组:肝动脉组(n=36):行自体肝移植手术,以40C乳酸林格液由门静脉灌肝40min,开放肝动脉及下腔静脉,10min后开放门静脉;门静脉组(n=36):行自体肝移植手术,门静脉开放恢复肝脏血流后10min再开放肝动脉血流;假手术组(n=6):打开腹腔,游离肝脏后关腹。观察各组小肠显微及超微结构变化并测定一氧化氮水平。结果与结论:术后各实验组不同时段先后出现小肠绒毛排列不整或紊乱,小肠黏膜细胞线粒体大小不一,明显肿胀,呈类圆形,内有空泡变性,严重者可见嵴减少、断裂或消失。小肠组织一氧化氮水平均升高。上述变化在术后12h达高峰。术后肝动脉先复流组小肠显微及超微结构损伤及小肠组织一氧化氮水平明显高于门静脉先复流组。提示,肝动脉早期复流可以通过早期肝脏供氧以减少移植肝脏的损害,但门静脉的延迟开放则加重了肝移植大鼠小肠的缺血/再灌注损伤。     

两袖套法大鼠同种异体减体积肝移植模型的建立

目的探讨建立稳定大鼠减体积原位肝移植模型的方法。方法利用两袖套法连接肝下下腔静脉及门静脉,单线连续吻合肝上下腔静脉。共完成120例大鼠减体积原位肝移植模型。结果顺利完成模型建立,移植术后大鼠均能自由活动,进食活跃。其2d和7d存活率分别为85.8%和83.3%。结论利用改进的两袖套法,可以建立稳定的大鼠同种异体减体积原位肝脏移植模型。     

无缝线化门腔侧-侧吻合磁性装置的研制

目的 介绍了一种用于门腔分流的磁吻合装置.包含两对子母磁环.它基于磁吻合技术,通过在门静脉和下腔静脉血管内外分别放入母磁环和子磁环后,子母磁环相吸并压迫并固定血管壁,从而在门/腔静脉建立磁吻合口.从而可实现无缝线化门腔侧侧吻合.该装置的优点是操作简单、吻合速度快、吻合效果理想,更重要的是门腔吻合口不会扩张,因而可显著降低肝性脑病的发生率.     

肝血流的病理生理改变与肝脏疾病的联系

目的 探讨肝脏门静脉、肝静脉管径及血流频谱的病理生理改变及其与肝脏疾病的联系.方法 在超声下观测并记录健康组30例,慢性乙型肝炎肝病组34例,慢性酒精肝及脂肪肝组32例,肝硬化门静脉高压组28例的肝静脉门静脉管径、血流频谱,及门静脉血流速度.结果 各种慢性疾病之间以及与正常人群之间在肝静脉、门静脉管径、血流频谱及血流速度几方面有统计学差异(P<0.05). 结论了解各种慢性肝病导致的肝血流理生理改变,并为临床早期诊断与治疗提供依据.     

肝移植后彩色多普勒超声的应用

背景：肝移植后监测移植肝脏并发症的发生情况,对肝移植的成功率及延长患者生存时间具有十分重要的意义。 目的：评价彩色多普勒超声对肝移植后并发症的监测效果。 方法：由作者采用电子检索的方式,在万方数据库(http://www.wanfangdata.com.cn/)及Medline数据库(http://www.ncbi.nlm.nih.gov/pubmed/)中以“彩色多普勒超声,肝移植,移植后并发症”为关键词,检索1990-01/2010-12有关彩色多普勒超声对肝移植后并发症监测效果的文章,共查到相关文献60余篇。经阅读标题、摘要、全文,排除内容重复、普通综述、Meta分析类文章后,筛选纳入22篇文献进行评价。 结果与结论：彩色多普勒超声检查具有无创、简便、直观、定位准确及可动态观察等优点,在肝移植后不仅能有效地检测肝脏大小、移植肝形态,而且可以从内部回声及血流动力学方面为肝移植后并发症的早期诊断提供线索,对临床及早治疗、保证肝移植成功具有重要的作用,是肝移植后监测的首选影像学检查方法。     

双袖套法大鼠异体原位肝移植模型改进与体会

目的    探讨建立一种灌注更彻底,操作更简便实用的改进双袖套法大鼠异体原位肝移植模型。　方法　在Kamada双袖套法的基础上进行改良。供、受体均为SD雄性大鼠,以4℃林格氏液经腹主动脉、肝门静脉低压双重灌注供肝,受体肝上下腔静脉采用血管膜端端“三点”标记吻合法,肝门静脉及肝下下腔静脉采用袖套吻合法,胆管吻合采用单管插管吻合。　结果　54例正式实验受体无肝期较短,手术1d存活率94.4%(51/54)。受体大鼠术后一般状况良好。　结论　改良后双袖套法大鼠原位肝移植模型操作简易快捷,成功率较高。     

改良法构建大鼠减体积肝移植模型

背景:目前有关活体肝移植后肝脏再生的研究较少。在大鼠肝移植实验中不断改进手术方法和技术,提高肝移植成功率是进行大鼠肝移植研究和获得可靠实验数据的基础。目的:验证以改良方法构建减体积肝移植大鼠模型的有效性。方法:选用健康SD大鼠,70对制备减体积肝移植改良前模型,100对制备减体积肝移植改良后模型。供体为雌性,受体为雄性,供体体质量比受体轻10g左右。改良前方案采用取下全肝后在修肝盆中进行减体积肝移植。改良后方案如下:供体采用单人裸眼操作,在取肝的过程中即进行减体积操作;修肝时将套管柄置于门静脉和肝下下腔静脉的正前方,将幽门静脉结扎点外翻于套管外并置于套管柄的左侧,即肝脏的左侧;将右肾静脉结扎点外翻于套管外并置于套管柄的右侧,即肝脏的右侧;供肝套管完成后用灌注液对门静脉和肝下下腔静脉进行冲洗;然后以左膈静脉为标识点进行7/0无损伤血管缝线吊线;受体采用双人裸眼配合操作,肝上下腔静脉吻合时,左右固定位点采用"8"字形外翻缝合,后壁和前壁分别采用连续吻合,门静脉和肝下下腔静脉采用改良的双袖套法,胆管支撑管法建立大鼠减体积的稳定模型。结果与结论:改良后供体手术时间为(32±2)min,修肝时间为(6±2)min,受体手术时间为(40±3)min,无肝期时间为(14±3)min。移植成功率为92%,移植后3d生存率为85%,移植后2周生存率83%。与改良前比较,移植后并发症发生率降低(P0.05),供肝的冷保存时间缩短(P0.05)。提示改良后的大鼠减体积肝移植模型比较稳定、可靠,移植成功率较高,移植后并发症发生率较低,为研究减体积肝移植后肝脏再生提供了有效的改良手段。     

Early graft hemodynamics in living related liver transplantation evaluated by Doppler ultrasonography

The aim of this study was to clarify the perioperative hemodynamics of liver grafts without vascular complications during and early after liver transplantation from living donors. This study was carried out in 4 child recipients (lateral segment left lobe grafts) and 6 adult recipients (right lobe grafts) of liver transplantation from living donors. The hemodynamics of the hepatic artery, portal vein, and hepatic vein of the grafts during and until 7 days after surgery were studied by Doppler ultrasonography. The maximum flow velocity of the hepatic artery, mean portal blood flow velocity, and pulsatility index (PI) of the hepatic artery increased in all 10 grafts with no vascular complication after vascular anastomosis. After surgery, the mean portal blood flow velocity showed a peak 3 days after surgery and reached a nadir 7 days after surgery in both the lateral segment left lobe grafts in children and the right lobe grafts in adults, but it was significantly higher in the right lobe grafts in adults (mean +/- SD 31.0 +/- 6.3 vs. 22.4 +/- 0.9 cm/sec). Also, as the hepatic artery blood flow velocity increased the portal blood flow velocity decreased, the hepatic blood flow during liver regeneration was suggested to be controlled by both the artery and portal vein. The range of PI of the hepatic artery was 0.60-1.86. The mean hepatic venous blood flow was stable throughout the observation period (30.4 +/- 8.8 cm/sec). Although the hepatic venous flow waves changed widely from pulsed waves to a flat flow, its changes did not suggest a vascular complication. Evaluation of changes by Doppler ultrasonography in the hemodynamics of the liver grafts without vascular complications during and early after liver transplantation from living donors is considered to be useful for accurate monitoring of the hemodynamics during liver regeneration and early detection of abnormalities.     

Role of models in understanding and interpreting clinical Doppler ultrasound

Mathematical and physical models are essential tools in both fundamental and clinically applied Doppler ultrasound research. In this paper we illustrate a variety of models and show how they can be used to understand and interpret clinical Doppler ultrasound signals, particularly from stenosed arteries. The physical models discussed include both steady and pulsatile flow systems, and also a flow visualization technique that can be used to interpret the Doppler signals at a fundamental hemodynamic level. The mathematical models deal with three different aspects of the Doppler signal: models that describe the mechanism of ultrasound scattering by blood, a model to stimulate the returned Doppler signal and a model that may be used to aid in the analysis of clinical recordings. Each of these models provides a more complete understanding of blood flow through normal and stenosed vessels and contributes to the interpretation of clinical Doppler signals.     

Microvascular anatomy of the non-lobulated liver of adult Xenopus laevis: A scanning electron microscopic study of vascular casts

The microvascular anatomy of the non-lobulated liver of adult Xenopus laevis was studied by scanning electron microscopy of vascular corrosion casts. Hepatic portal veins and hepatic arteries entered hepatic lobes at the hiluses, hepatic veins left at these sites. Intraparenchymal, hepatic portal veins branched up to 10 times before terminal portal venules supplied liver sinusoids. Hepatic arteries closely followed portal vessels. Arteriolar side branches formed anastomoses with close by portal venules (arteriolar-portal anastomoses; APAs), liver sinusoids (arteriolar-sinusoidal anastomoses; ASAs), and peribiliary plexus vessels. Distally, hepatic arteries anastomosed with terminal portal venules having >100 μm in diameter. Liver sinusoids formed a dense three-dimensional network displaying signs of non-sprouting and sprouting angiogenesis evidenced by “holes” and blind ending tapering cast vascular structures (sprouts), respectively. Sinusoids drained via efferent hepatic veins. Right and left hepatic veins drained into the posterior caval vein. Locally, a dense honeycomb-like 3D-meshwork of resin structures was found around terminal portal venules and hepatic arteries. These networks were fed by hepatic arterioles and drained into adjacent terminal portal venules. As their morphologies differed significantly from sinusoids and they were found at sites where diffuse lymphoid tissue is described, we are convinced that they represent the vasculature of diffuse lymphoid tissue areas. Frequencies and diameter ratios of hepatic portal venules versus hepatic arterioles anastomosing with the former (APAs) implicate that the arterial supply contributes to the oxygenation of parenchymal and stromal cells rather than to a significant increase in blood flow towards hepatic sinusoids.     

Two-dimensional pulse Doppler echography in chronic hepatitis

A separate estimation of blood flow in the portal and hepatic veins using ultrasonic two-dimensional tomography and impulse Doppler echography of the liver was tried in 30 chronic sufferers with hepatitis versus 31 healthy controls. Two-dimensional impulse Doppler echography recorded the blood flow spectrum in the right hepatic vein at the site of its entering of vena cava inferior as well as in the portal vein at the portal fissure simultaneously with ECG. The index of portal blood flow and that of right hepatic vein flow in systole are proposed. The above method warrants a separate estimation of hepatic circulation in hepatic pathology whereas its combination with ultrasonic tomography increases its diagnostic potential at early stages of hepatic impairment. The analysis of the central and hepatic hemodynamics established hepatic circulation participation in regulation of central hemodynamics.     

布-加综合征的彩色多普勒超声诊断及与肝硬化的鉴别诊断

目的探讨彩色多普勒超声在诊断布-加综合征及与肝硬化的鉴别诊断中的应用价值。方法32例布-加综合征患者（男性19例,女性13例,平均年龄37岁）和40例门脉性肝硬化患者（男性28例,女性12例,平均年龄48岁）,分别接受二维超声、彩色多普勒超声和频谱多普勒超声检查,并对获得的资料进行回顾性分析。所有患者经血管造影和/或病理、CT证实。结果布-加综合征的典型特征是病变主要累及下腔静脉和肝静脉,病变处管腔闭塞或狭窄,其内血流紊乱,并可出现侧支循环和交通支;肝硬化患者主要表现为肝脏缩小、脾大、门静脉增宽、腹水,血流动力学改变主要以门静脉和肝静脉为主。结论彩色多普勒超声对布-加综合征、肝硬化的诊断及鉴别诊断符合率较高,为诊断布-加综合征和肝硬化提供有效手段,对选择合理治疗方案及评价治疗效果具有指导意义。     

先天性胆道闭锁合并卵圆孔未闭患儿肝移植围术期血流动力学及心功能变化

目的 探讨合并卵圆孔未闭的先天性胆道闭锁患儿行原位肝移植围术期血流动力学及心功能的变化。方法 回顾性分析2017年2月~2019年2月我院择期行原位肝移植术的先天性胆道闭锁患儿69例,根据心脏多普勒彩超检查结果分为卵圆孔未闭组（P组,卵圆孔＞3 mm）27例和非卵圆孔未闭组（N组,卵圆孔≤3 mm）42例,比较两组诱导插管后（T1）,门静脉阻断即刻（T2）,无肝期10 min（T3）,门静脉开放即刻（T4）,新肝期1 h（T5）,术毕（T6）时HR、MAP、CVP、SV、CO、CI、dp/dt和CCE及不良心血管事件发生率。结果 两组T4时点MAP和CI低于T1时点,差异有统计学意义（P＜0.05）;两组T2、T4时点SV和CO低于T1时点,T6时点SV和CO高于T1时点,差异有统计学意义（P＜0.05）;两组T2~T6时点CCE低于T1时点,差异有统计学意义（P＜0.05）;两组各时间点均未发生严重不良心血管事件。结论 与非卵圆孔未闭患儿比较,合并卵圆孔未闭的先天性胆道闭锁患儿行原位肝移植围术期血流动力学及心功能变化无差异,术前无明显临床症状或右向左分流致心功能不全,无需对卵圆孔未闭进行手术治疗。     

彩超对肝内三种常见强回声病灶的鉴别与诊断研究

目的 观察彩色多普勒超声检查对三种不同肝部强回声病灶（胆管结石、肝内钙化灶、肝内胆管积气）的鉴别诊断。方法 对我院2017年9月~2018年3月收治的肝内胆管结石20例和肝内钙化灶40例、肝内胆管积气20例患者的相关资料和超声资料进行分析,比较三种不同肝部强回声病灶的彩超结果。 结果 20例肝内胆管结石患者中,肝左右叶同时发病的有6 例,左叶占30.00%,右叶占40.00%,彩超声像图显示为结石沿着肝内胆管分布,呈簇状,结石通常为多发,表现为斑点状或条索状、团状以及不规则形,超声检查会出现高强回声,后部通常伴有明显的回声影,肝内胆管存在不同程度扩张,和门静脉分支呈现“平行管”特征。40例肝内钙化灶患者中,肝左叶有患者20例,位于肝右叶患者17 例,肝左右叶同时存在患者有3例,彩超检查可以表现为强回声,可见大小不一,形态为团状或斑块状的影像,通常为单发,可分布于肝内的多处,肝内胆管不存在无明显扩张。在20例肝内胆管积气患者中,有6例患者伴有胆道手术病史,彩超声像图可体现出肝内胆管内有强回声出现,体位发生改变时,其形态和位置均会有变化,如发生的强回声位于肝内胆管的前壁处,后方会伴有“彗尾征”图像。结论 彩超可以实现多角度和多切面的扫描检查,结合不同的声像图信息,可以诊断肝内胆管结石、肝内钙化灶、肝内胆管积气,在临床诊断具有非常重要的作用。     

左外叶活体肝移植的解剖学研究

目的：模拟左外叶活体肝移植门静脉、肝动脉和胆管的切取方法。方法：解剖正常人肝脏标本30具，观察肝脏铸型标本30具，测量门静脉、肝动脉及胆管长度、管径及属支或分支分布情况。结果：左外叶门静脉的血供来自门静脉左支，主要为左外叶上段门静脉支、左外叶下段门静脉支；动脉主要来源于肝固有动脉、肝左动脉、肝中动脉，偶有迷走动脉支；胆道引流属支有左外叶上段胆管支、左外叶下段胆管支。结论：左外叶解剖变异较多，活体取肝前应仔细研究其结构特点，设计合理的切取模式；对门静脉、肝动脉和胆管支需行必要的整形，以便与受体相应的管道进行吻合。     

Modeling the hepatic arterial buffer response in the liver

In this paper we present an electrical analog model for the hepatic arterial buffer response (HABR), an intrinsic regulation mechanism in the liver whereby the arterial flow counteracts the changes in portal venous flow. The model itself is a substantial simplification of a previously published model, with nonlinear arterial and portal resistors introduced to account for the dynamic HABR effects. We calibrate the baseline model using published hemodynamic data, and then perform a virtual portal occlusion simulation where the portal vein is half or fully occluded. The simulation results, which suggest that the increased arterial flow cannot fully compensate lost portal perfusion, are consistent with clinical reports and animal model findings. Since HABR functions in both the whole liver and liver graft after transplantation, we also simulate blood flow in a virtual right-lobe graft by adjusting the electronic component parameters in the electric circuit, and our model is able to reproduce the portal venous hyperperfusion and hepatic arterial hypoperfusion conditions due to the HABR effects.     

A computer simulation model for Doppler ultrasound signals from pulsatile blood flow in stenosed vessels

A computer simulation model based on an analytic flow velocity distribution is proposed to generate Doppler ultrasound signals from pulsatile blood flow in the vessels with various stenosis degrees. The model takes into account the velocity field from pulsatile blood flow in the stenosed vessels, sample volume shape and acoustic factors that affect the Doppler signals. By analytically solving the Navier-Stokes equations, the velocity distributions of pulsatile blood flow in the vessels with various stenosis degrees are firstly calculated according to the velocity at the axis of the circular tube. Secondly, power spectral density (PSD) of the Doppler signals is estimated by summing the contribution of all scatterers passing through the sample volume grouped into elemental volumes. Finally, Doppler signals are generated using cosine-superposed components that are modulated by the PSD functions that vary over the cardiac cycle. The results show that the model generates Doppler blood flow signals with characteristics similar to those found in practice. It could be concluded that the proposed approach offers the advantages of computational simplicity and practicality for simulating Doppler ultrasound signals from pulsatile blood flow in stenosed vessels.