经颈静脉肝内门体静脉分流研究进展与肝脏静脉系统可视化

门静脉高压症的外科治疗虽已步入肝移植时代，但由于肝移植手术的供肝有限，费用昂贵及技术有待进一步完善等原因，非手术的血管介入治疗具有着现实的应用价值和临床地位。     

下腔静脉和肝静脉末段的应用解剖学

在40例成人尸体标本上，观测下腔静脉和肝静脉末段的位置，口径，方向，肝静脉注入下腔静脉的形式可分为4种类型，其中以3分支型最为多见，占57．5％，肝静脉与水平面的夹角；肝右静脉约为30°，肝中静脉约为55°，肝左静脉约为55°，下腔静脉和肝静脉末端的体表投影位于右侧胸前壁内侧半，剑突尖水平面与膈穹水平面之间，上述资料对下腔静脉和肝静脉末端超声波检查等临床应用有参考价值。     

基于W-Net的肝静脉和肝门静脉全自动分割

基于术前CT影像的肝静脉和肝门静脉分割对于进行肝脏分段具有重要的临床价值。但在肝脏的静脉期CT影像中,肝静脉和肝门静脉的灰度差异很小,血管结构也错综复杂,因此自动提取三维的肝静脉和肝门静脉一直是个难题。为解决此难题,提出一种基于卷积神经网络(convolutional neural network,CNN)的网络结构W-Net。该结构利用肝静脉和肝门静脉在三维结构上的差异,为全部肝血管和门静脉的提取分别设置损失函数,通过优化两个损失函数的加权和,自动学习全部肝血管和门静脉的三维结构特征,使全部肝血管和肝门静脉均达到优化的提取效果,两者相减即可得到肝静脉。采用公开数据集3Dircadb01中的10组延迟期腹部CT影像用于网络模型构建,另外10组用于测试。结果显示,肝区全部血管Dice系数达到0.715,准确率达到0.970;肝静脉Dice系数达到0.597,准确率达到0.984;肝门静脉Dice系数达到0.608,准确率达到0.970。通过10组临床数据进行测试,所构建的网络均能将肝静脉和肝门静脉有效地分割开。实验结果表明,所提出的方法具有较好的特征提取能力及泛化能力,在公开数据和临床数据中都有较好的表现。     

基于冠状面数据的肝静脉和肝内门静脉的三维重建

目的:构建基于肝连续薄层冠状断面数据集的肝静脉和肝内门静脉的三维数字化可视模型。方法:应用数控冷冻铣削技术获取1例肝的连续薄层冠状断面数据集;采用体绘制和面绘制的方法,通过人工干预对数据集中肝内管道系统进行人工识别提取和图像数据分割;运用3D医学可视化软件实现三维重建,构建肝静脉和肝内门静脉的三维可视化模型。结果:肝静脉和肝内门静脉的可视化模型可清晰显示门静脉及其分支和肝静脉及其属支的空间构形,真实地再现了肝门静脉和肝静脉之间复杂的空间毗邻关系。模型中的肝静脉和肝门静脉可单独或总体显示,可在三维空间位置上绕任意轴旋转任意角度,并能从不同的角度对某一血管分支进行多角度、多方位的观察。结论:高质量的二维图像、精确的数据分割和合适的三维重建方法保证了三维数字化可视模型的真实性和准确性。     

下腔静脉口和肝静脉入口的间距及其临床意义

目的：为在心脏外科手术体外循环中插入下腔静脉导管的最佳长度提供解剖学基础。方法：用游标卡尺测量１０１例成人尸体的下腔静脉口和肝静脉入口之间的距离。结果：下腔静脉口和最高一条肝静脉入口上缘的间距为２０．３±５．２ｍｍ；下腔静脉口和最低一条肝静脉入口下缘的间距为４０．７±７．２ｍｍ。这两个间距的测量值相比，有显著性差异（ｔ检验Ｐ＜０．００１）。最高一条肝静脉入口上缘和最低一条肝静脉入口下缘的间距为２０．３±７．１ｍｍ。结论：心脏外科手术体外循环时，插入下腔静脉内的导管２０ｍｍ长，能使肝静脉血引流畅通。     

肝门静脉的应用解剖

目的观测肝门静脉的形态特征和分支分布规律,为诊断和治疗肝脏疾病提供更为详尽的形态学资料。方法 50例肉眼观察无病变的成人肝标本,对肝门静脉分支分型等形态特征进行解剖观察,测量肝门静脉主干及其主要分支的相关数据并进行统计学分析。结果肝门静脉主干54.0%在肝实质外分叉,其分叉点距肝实质的垂直距离为(8.94±3.17)mm;34.0%紧贴肝实质分叉。左支主干长(47.44±7.23)mm;左支横部长(23.90±5.29)mm,外径为(7.43±1.09)mm,矢部长(24.02±4.97)mm,外径为(7.07±1.36)mm,角部角度为(114.18±22.59)°;右支主干长(20.63±6.59)mm,外径为(9.26±1.77)mm。依据肝门静脉的分支情况可将其分为8型。结论肝门静脉变异情况并不少见,其分叉点距肝实质的垂直距离及左、右支主干径值与分支等均存在一定的变化,在肝外科手术实施时,对肝门静脉主干分支各型应给予高度的重视。。     

肝静脉与门静脉的解剖及其在经颈静脉肝内门体分流术中的应用

目的：探讨肝静脉与门静脉的解剖及在经颈静脉肝内门体分流术（TIPS）中的应用。方法：在PUBMED、CNKI及维普等数据库中,查阅近年来国内外有关肝静脉、门静脉的正常解剖与变异及其在TIPS中应用的文献,进行分析总结。结果：肝静脉系统主要由肝右静脉、肝中静脉、肝左静脉3支组成,肝左静脉发生变异最多,肝中、右静脉变异相对少见。门静脉在肝门处进入肝脏,以分为左支和右支两主干这一类型居多,其解剖形态因地区、种族等因素而有差异。肝静脉和门静脉呈向后向上与向前向下的空间关系,经典TIPS是从肝右静脉距下腔静脉入口约2cm处向门静脉分叉部或右支内穿刺建立分流道。结论：肝静脉、门静脉的正常解剖与变异及其空间关系对顺利完成TIPS的操作至关重要。熟悉肝静脉、门静脉正常解剖和变异可提高TIPS的成功率,减少和避免并发症的发生。     

经股静脉行肝内门-体静脉分流插管术的回归方程及临床意义

目的　为临床经股静脉肝内门 体静脉分流插管术提供解剖学依据。方法　在 4 5具成人尸体上观测了双侧股静脉穿刺点至肝中静脉的长度 ,与胸骨颈静脉切迹到耻骨联合上缘的距离作相关回归分析。结果　从左侧股静脉穿刺点至肝中静脉的长度为 (3 9 83± 3 87)cm ,直线回归方程为 ^y =3 0 9± 0 71x;P <0 0 2 5 ;从右侧股静脉穿刺点至肝中静脉的长度为(3 8 4 9± 3 60 )cm ,直线回归方程为 ^y =3 0 3± 0 67x ;P <0 0 1;左、右侧股静脉与髂外、髂总静脉的夹角分别为 163 2 2°± 5 5 7°和 166 0 0°± 5 10° ,左、右侧髂外、髂总静脉与下腔静脉的夹角分别为 14 6 4 4°± 9 0 7°和 15 8 0 0°± 5 2 3°。结论　经右侧股静脉插管较左侧更为有利 ,可根据方程计算出从股静脉穿刺点到肝中静脉的长度     

Direct intrahepatic portocaval shunt through transhepatic puncture via retrohepatic inferior vena cava: applied anatomical study

Background  DIPS is to create a portosystemic shunt directly between the portal vein and the retrohepatic inferior vena cava (RIVC) without passing through the hepatic vein. It has been recommended that the DIPS could be applied when routine TIPS is unsuccessful or the patient has anatomical variations of the hepatic vein. The aim of this study was to identify the safe area of the RIVC where the DIPS can be safely established. Materials and methods  The lengths of the safe and unsafe areas of the RIVC were measured. The tributaries of the RIVC were examined. The diameter of these tributaries was measured and their incidence and relation to the safe area of the RIVC were observed. The puncture distances of DIPS and TIPS were measured and compared. Results  The liver together with the RIVC was collected from 31 adult cadavers (age 32–65 years; M/F 25/6). 1. The safe and unsafe areas of the RIVC: the total length of the RIVC was 70.1 ± 13.0 mm (33.1–92.0 mm), whereas the length of the safe area of the RIVC was 54.3 ± 12.3 mm (20.2–71.1 mm), which was about over 70% of the total length. The length of the unsafe area at the upper end was 5.9 ± 1.8 mm (3.0–10.2 mm), and at the lower end was 8.9 ± 2.9 mm (3.1–20.0 mm). 2. The tributaries of the RIVC: In about 90% of the cadavers (90.3%; 28 out of 31), the LHV and MHV had the common trunk. The other three cadavers (9.7%; 3 out of 31) had independent RHV, MHV and LHV. There were 217 of small hepatic veins draining into the lower segment of the RIVC. Over 70% of the small hepatic veins were smaller than 5 mm in diameter and distributed on the anterior and left wall of the lower RIVC. 3. Puncture distances of the DIPS and TIPS: The distances from the bifurcation of the portal vein to the RIVC, to the right and to middle hepatic veins were 31.2 ± 7.9 mm (15.0–47.2 mm), 38.6 ± 8.1 mm (17.2–59.0 mm), and 46.6 ± 8.2 mm (34.0–68.1 mm), respectively. Thus, the puncture distances via the RIVC, RHV and LHV were significantly different (P < 0.001). The puncture distance of the DIPS was shortest. Conclusion  Anatomically, DIPS is a feasible interventional procedure to make a intrahepatic shunt between IVC and portal vein directly, and has its anatomical advantages compared to TIPS.     

Interruption of the inferior vena cava with azygos termination associated with congenital absence of portal vein

The authors report an exceptional and well-documented case of interruption of the retrohepatic segment of the inferior vena cava with an “azygos continuation”, combined with absence of the portal vein. The only known combination of congenital anomalies of the inferior vena cava and the portal vein was that of an “azygos continuation” and a preduodenal portal vein. The double interruption, portal and inferior caval, may be associated with a disturbance of preferential flows induced by the left umbilical thrust. According to hemodynamic theory, the left umbilical flow is the determining factor in organogenesis of the portal vein and the retrohepatic segment of the inferior vena cava.     

The hepatic veins: Anatomy and classification on single slice spiral CT in North Indian population

AimsTo find out the normal pattern of hepatic veins in the North Indian population and to categorize them.MethodsThe present study was conducted on 100 patients whose spiral CT abdomen was performed for various medical conditions in the department of radiodiagnosis.ResultsFour categories were recognized. Category-1, when right hepatic vein drains independently into the inferior vena cava whereas middle and left hepatic veins join together to form a common trunk before draining into the inferior vena cava. It was observed in 74% patients. Category-2 was observed in 2% patients, where right & middle hepatic veins join to form a common trunk and left hepatic vein drain independently into the inferior vena cava. Category-3 was observed in 21% patients, where all the three major hepatic veins drain independently into the inferior vena cava. Category-4 was observed in 3% patients, where all the three major hepatic veins join together to form a common trunk before draining into the inferior vena cava.ConclusionsCategory-1 is the most common pattern of major hepatic vein drainage found in the North Indian population. The present study also concluded that single right, middle and left hepatic vein is the most common pattern of hepatic veins present in the North Indian population. Caudate lobe is drained by more than one vein in majority of North Indians. Also superomedial vein, right accessory vein and inferior right hepatic vein are the most common accessory veins present in the North Indian population.     

Clinical outcomes of transjugular intrahepatic portosystemic shunt for portal hypertension: Korean multicenter real-practice data

Background/Aims

This retrospective study assessed the clinical outcome of a transjugular intrahepatic portosystemic shunt (TIPS) procedure for managing portal hypertension in Koreans with liver cirrhosis.

Methods

Between January 2003 and July 2013, 230 patients received a TIPS in 13 university-based hospitals.

Results

Of the 229 (99.6%) patients who successfully underwent TIPS placement, 142 received a TIPS for variceal bleeding, 84 for refractory ascites, and 3 for other indications. The follow-up period was 24.9±30.2 months (mean±SD), 74.7% of the stents were covered, and the primary patency rate at the 1-year follow-up was 78.7%. Hemorrhage occurred in 30 (21.1%) patients during follow-up; of these, 28 (93.3%) cases of rebleeding were associated with stent dysfunction. Fifty-four (23.6%) patients developed new hepatic encephalopathy, and most of these patients were successfully managed conservatively. The cumulative survival rates at 1, 6, 12, and 24 months were 87.5%, 75.0%, 66.8%, and 57.5%, respectively. A high Model for End-Stage Liver Disease (MELD) score was significantly associated with the risk of death within the first month after receiving a TIPS (P=0.018). Old age (P<0.001), indication for a TIPS (ascites vs. bleeding, P=0.005), low serum albumin (P<0.001), and high MELD score (P=0.006) were associated with overall mortality.

Conclusions

A high MELD score was found to be significantly associated with early and overall mortality rate in TIPS patients. Determining the appropriate indication is warranted to improve survival in these patients.     

The role of transjugular intrahepatic portosystemic shunt in patients with portal hypertension: Advantages and pitfalls

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective interventional procedure to relieve portal hypertension, which is a main mechanism for the development of complications of liver cirrhosis (LC), such as variceal hemorrhage, ascites, and hepatorenal syndrome. However, the high incidence of adverse events after TIPS implementation limits its application in clinical practice. Esophageal variceal hemorrhage is one of the major indications for TIPS. Recently, preemptively performed TIPS has been recommended, as several studies have shown that TIPS significantly reduced mortality as well as rebleeding or failure to control bleeding in patients who are at high risk of treatment failure for bleeding control with endoscopic variceal ligation and vasoactive drugs. Meanwhile, recurrent ascites is another indication for TIPS with a proven survival benefit. TIPS may also be considered as an effective treatment for other LC complications, usually as an alternative therapy. Although there are concerns about the development of hepatic encephalopathy and hepatic dysfunction after TIPS implementation, careful patient selection using prognostic scores can lead to excellent outcomes. Assessments of cardiac and renal function prior to TIPS may also be considered to improve patient prognosis.     

The hepatic haemodynamic response to acute portal venous blood flow reductions in the dog

The hepatic haemodynamic response to acute reductions in portal venous blood flow was investigated in 14 anaesthetized normal dogs. A side-to-side mesocaval anastomosis was constructed to enable varying degrees of portal flow to be diverted into the inferior vena cava by suitable manipulations of the shunt diameter. Measurements of portal venous and hepatic arterial blood flow were made with electromagnetic flowmeters.A linear relationship was observed between the degree of reduction in portal flow and the magnitude of the resulting hepatic arterial hyperaemic response. Hepatic arterial vascular resistance showed a decrease which became more pronounced the greater the degree of reduction in portal flow. For every 1.0 ml·min^–1 100 g^–1 decrease in portal flow, the hepatic arterial flow increased by a mean of 0.24 ml ·min^–1·100g^–1, a value representing the average compensatory capacity of the arterial response. Arterial flow improvement therefore provided some degree of protection against severe falls in total liver blood flow. However, it provided even more effective protection against any fall in total hepatic oxygen consumption, which showed only a very gradual decrease with reduced hepatic portal blood flow.     

A morphological and functional study of the cavo-hepatic junction in the human

Summary The authors studied the morphological and structural aspects of the junctions between the hepatic veins and the inferior vena cava. The study was carried out on 20 specimens obtained from adult cadavers of both sexes, fixed in 10% formaldehyde solution. The hepatic veins with their junctions on the inferior vena cava were isolated. Then a macroscopic analysis of the openings of the hepatic veins into the inferior vena cava was performed. Part of this material was embedded in paraffin, submitted to serial sectioning and stained with Azan's trichrome and resorcin-fuchsin. Three hepatic veins were observed in all cases: right, left and the middle. In 20% of the cases the middle hepatic vein opens directly into the inferior vena cava. The hepatic vein openings are supported by two pillars inferiorly united through a semilunar fold. The hepatic vein wall is greatly thickened at the level of its junction with the inferior vena cava, showing a large ammont of muscular and collagenous fibers. These bundles constitute a sphincter-like formation which may play a physiological role in the control of the hepatic circulation.Les auteurs étudient les aspects morphologiques et structuraux du carrefour hépatico-cave. Cette étude porte sur 20 sujets adultes des deux sexes après formolisation. Les veines hépatiques et leurs terminaisons dans la veine cave inférieure sont prélevées, étudiées sur le plan macroscopique et incluses dans la paraffine. Les coupes sériées sont fixées selon la technique d'Azan. Trois veines hépatiques sont retrouvées dans tous les cas : les veines hépatiques droite, moyenne et gauche. Dans 20% des cas, la veine moyenne s'ouvre directement dans la veine cave inférieure. L'ostium des veines hépatiques s'appuie sur deux piliers réunis à leur partie inférieure par un repli semilunaire. La paroi des veines hépatiques au niveau de leur ostium est très épaisse avec un fort contingent de fibres musculaires et collagènes. Les fibres musculaires réalisent un véritable sphincter qui peut jouer un rôle physiologique dans le contrôle de la circulation hépatique.This report was made at the Anatomy Department of the Biological Sciences Center of UFPE     

Variations of the bilateral testicular veins: embryological and clinical considerations

Variations of the bilateral testicular veins were observed during routine dissection of the posterior abdominal wall in a 77-year-old male Japanese cadaver. The right testicular vein consisted of the lateral and medial testicular veins. The right lateral testicular vein drained into the right renal vein. The right medial testicular vein accompanied the right testicular artery to ascend obliquely and drained into the left aspect of the inferior vena cava. The left testicular vein was composed of the lateral, middle and medial testicular veins. Three left testicular veins accompanied the left testicular artery to course cranially and then finally drained into the left renal vein.