Main accessory sulcus of the liver

It has been proposed that the superficial part of the portal fissures weakens the surface hepatic parenchyma, allowing the development of accessory sulci caused by diaphragmatic pressure. To evaluate the relationship of the sulci in the antero-superior surface of the right liver with the right portal fissure, macroscopic post mortem examination of 85 livers was carried out and radio-opaque resins were injected into the portal and hepatic venous systems to obtain vascular casts. After formalin fixation, the 85 livers also underwent CT and MR scans and 3D image elaboration. Diaphragmatic sulci were found in 32 cases. We studied the sulci located in the right liver, i.e., those that lay to the right of the line of Cantlie. They were found in 28 instances and in 16 cases they were multiple. In the livers with a single sulcus, it extended between the anterior and right surfaces of the right liver and showed a curved course downward and forward, toward the inferior margin. In the cases with multiple sulci, one sulcus always showed a course similar to that of the single sulci. The 28 sulci, with similar position and course, showed variable characteristics (mean length=7.6 +/- 2.7 cm, mean width=0.8 +/- 0.7 cm, mean depth=1.4 +/- 0.8 cm). Both radiological images and corrosion casts showed a correspondence between these sulci and the right hepatic vein and the right portal fissure in 71% of cases. These sulci may represent the variable expression (cranial, intermediate, or caudal portions) of a potential sulcus, the main accessory sulcus (MAS), that develops along a theoretically predictable course corresponding to the superficial part of the right portal fissure. The high prevalence of location of the MAS at the level of the upper part of the right portal fissure can be ascribed to the presence at this level of the watershed between the roots of the tributaries of the hepatic veins coming from segments VIII and VII, draining respectively into the middle and right hepatic veins. Thus, the coexistence of the two portal and hepatic venous boundaries may represent a further predisposition to the effects of diaphragmatic pressure. The MAS may represent a marking for the right portal fissure, and hence a superficial reference for the deep course of the right hepatic vein.     

Sulci of the liver found after death: Their nature and potential teaching value

Accessory sulci of the liver are more commonly found after death than in life, raising questions as to their causation and possible classification. We have analyzed a group of 180 livers sampled from un‐embalmed (96) and embalmed cadavers (84). In un‐embalmed cadavers, no accessory sulci were found on the diaphragmatic surface in 58 cases. Diaphragmatic sulci were found in the right lobe of 38 livers. When removed from the abdominal cavity and placed flat on the examination table (the “bench position”) all 58 livers without sulci appreciable in the abdominal cavity showed the appearance of two sulci. The first ran from the right side of the inferior vena cava (IVC), curving anteriorly to the inferior border of the liver, at a point midway between the right extremity of the inferior border and the gallbladder fossa, concave towards the left. The second sulcus ran from the left side of the IVC, curving anteriorly to reach the inferior border of the liver at the level of the gallbladder fossa, concave towards the right. With progressive side‐to‐side manual compression, the sulci on the diaphragmatic surface become more evident. Division of the hepatic parenchyma along the two sulci exposed the right and middle hepatic veins respectively in more than 90% of cases. In embalmed cadavers, 24 livers showed antero‐posterior sulci in the superior surface, visible and palpable on the liver examined in situ. When the livers with sulci had been removed from the abdomen for further examination, the appearance of the superior surface did not change. In a removed liver, accessory sulci can be divided into true, “diaphragmatic,” sulci and “false” sulci due to the position of the free liver on the examination table. The “false” sulci may be considered as further morphological evidence of the functional anatomical division of the liver. Their demonstration may also be useful in teaching its topographical and surgical anatomy. Clin. Anat. 26:592–597, 2013. © 2012 Wiley Periodicals, Inc.     

Recovery from hepatic necrosis following acute portal vein embolism with special reference to reconstruction of occluded vessels.

We examined the morphological and haemodynamic changes in the livers of rats following acute obstruction of portal vein branches by the injection of agar into the portal vein. Histological and angiographic examinations of the liver were performed after measurements of portal vein pressure in vivo and portal vascular resistance by an isolated liver perfusion method. Portal vein embolism induced hepatic necrosis in the centrilobular and midzonal areas, which was rapidly resorbed and replaced by regenerated liver cells leaving no trace. This recovery from hepatic necrosis was closely related to recanalization of obstructed portal vein branches, which led to falls in both the elevated portal vein pressure and the increased portal vascular resistance following embolization.     

A study of the accessory hepatic vein to segments VI and VII with a morphological reconsideration of the human liver

Introduction The liver is supplied by the common hepatic artery from the celiac trunk and by the portal vein from the gastrointestine. This double blood supply to the liver by the hepatic artery and the portal vein produced a complicated structure in the liver. For the blood outflow, we can see right, intermediate and left hepatic veins, and irregular veins: the accessory hepatic veins. These veins drain the blood in the liver into the inferior vena cava. In this study, we studied the layout of the accessory hepatic vein draining segments 6 and 7 in the human livers and attempted to reconsider the structure of the liver by the layout of the accessory hepatic vein. Methods Sixty livers were subjected in this study. They were prepared by using forceps to trace the layout of the blood vessels inside the livers. We carefully examined the relation between the layouts of the accessory vein to the segments 6 and 7 and of the portal vein. The confluence patterns of the accessory hepatic vein into the inferior vena cava were also examined to find the character of the vein. The relation between the accessory hepatic vein and standard hepatic veins was also studied. Results We found 2.2 accessory hepatic veins in one liver on average in our study. The vein was always within the area of segments 6 and 7, and did not surpass the boundary. We found at most five accessory hepatic veins in a liver in two cases. The accessory hepatic vein to the segments 6 and 7 always had its stem on the dorsal side to the portal vein. Different from the stem, the periphery of the accessory hepatic vein freely distributed with the peripheral branches of the portal vein. The area distributed by the accessory vein was also always dorsal part within the segments 6 and 7. The vein was small usually, but was big in few cases. When the vein was big, the area became solely drained by the accessory vein, because the standard hepatic veins (right and intermediate hepatic veins) did not reach the area, and we did not find any communication between the accessory vein and the standard veins. As the remaining region in the segments 6 and 7 became smaller, the draining right standard hepatic vein became shorter and smaller. Discussion The region drained by the accessory hepatic vein excluded the standard hepatic veins. Therefore, there are two different draining venous networks in the area of segments 6 and 7 classified by Couinaud. Conclusion The accessory hepatic vein draining segments 6 and 7 distributed somewhere dorsal side in the segments 6 and 7. The area where the accessory vein distributed was the region where standard hepatic veins did not reach. This would suggest that the region drained by the accessory hepatic vein makes an isolated segment in the liver in the segments 6 and 7 by the Couinaud’s Classification. The area might have a unique blood circulation system.     

左、右肝管全程剖开的应用解剖

用6个取自新鲜成人尸体的肝脏,注入ABS丙酮溶液制成铸型。另外还解剖了经固定的42例(成人32,儿童10)肝脏标本,测量左、右肝管长度、管径,并观察左、右肝管与肝动脉、门静脉及其分支的关系。提出了左、右肝管全程剖开的手术方法和注意事项。     

Anatomy of the portal branches and the hepatic veins in the caudate lobe of the liver

The objective of this study was to analyze the caudate portal branches and their relationships with the hepatic caudate veins and propose a new nomenclature for the caudate branches based on their territory of distribution. We realized the fine dissection of the veins of the caudate lobe in 40 human livers fixed and preserved in formalin. In 15/40 (37.5%) cases there was a single branch to the caudate lobe. In 25/40 (62.5%) cases there was more than one branch, with a posterior caudate branch in 20/40 (50%) cases, an anterior caudate branch in 15/40 (37.5%) cases, a left caudate branch in 14/40 (35%) cases, and a right caudate branch in 8/40 (20%) cases. The most frequent combination detected (11/40, 27.5% of cases) was that of the posterior and anterior branches. The venous drainage of the caudate lobe and its papillary process was provided by the superior caudate hepatic vein in 23/40 (57.5%) cases, by the middle caudate vein in 35/40 (87.5%) cases (which was the only vein in 12/35 cases), and by the inferior caudate vein in 16/40 (40%) cases. In 11/40 (12.5%) cases there were accessory caudate veins, which emptied into the left and intermediate hepatic veins. The portal branches and the hepatic veins related to the caudate process were studied. In conclusion, the new nomenclature analyzes more precisely the distribution of the caudate portal branches.     

Anatomy of hepatic arteriolo‐portal venular shunts evaluated by 3D micro‐CT imaging

The liver differs from other organs in that two vascular systems deliver its blood – the hepatic artery and the portal vein. However, how the two systems interact is not fully understood. We therefore studied the microvascular geometry of rat liver hepatic artery and portal vein injected with the contrast polymer Microfil^®. Intact isolated rat livers were imaged by micro‐CT and anatomic evidence for hepatic arteriolo‐portal venular shunts occurring between hepatic artery and portal vein branches was found. Simulations were performed to rule out the possibility of the observed shunts being artifacts resulting from image blurring. In addition, in the case of specimens where only the portal vein was injected, only the portal vein was opacified, whereas in hepatic artery injections, both the hepatic artery and portal vein were opacified. We conclude that mixing of the hepatic artery and portal vein blood can occur proximal to the sinusoidal level, and that the hepatic arteriolo‐portal venular shunts may function as a one‐way valve‐like mechanism, allowing flow only from the hepatic artery to the portal vein (and not the other way around).     

与LC术有关的胆囊动脉解剖

目的：为临床ＬＣ术提供形态学资料。方法：随机选用３０例肝脏标本,经胆囊动脉及门静脉右支注入乳胶后,在６倍大视场显微镜下观察胆囊动脉的起源、行程、及其与肝脏的关系。结果：据胆囊动脉深、浅支行径的不同,将其分为５种类型。其深支可发出肝支和胆囊支,分别供应肝脏和胆囊;并特别对肝支进入胆囊窝的部位进行了观察和统计。胆囊静脉从胆囊窝底注入门静脉右支,而部分门静脉右支位置表浅,参与组成了胆囊床。结论：处理胆囊窝时,尤应重视胆囊动脉肝支和位置表浅的门静脉右支的存在,以防止出血。     

基于肝内肝门静脉解剖的肝脏右前叶分段新概念

目的根据肝内肝门静脉的走形分布,提出肝脏分段的新概念,为影像学和肝脏外科提供资料。方法采用60例正常的活体肝移植供肝影像资料,研究右前叶肝内肝门静脉的走形和分布以及肝静脉及其属支的回流范围,10例Mevis三维软件重建图像,探讨两者之间的关系。结果 Couinaud分段中的Ⅷ段门脉支可大致分为腹侧支和背侧支,最多可达4支;约90%的背侧支越过肝右静脉分布到Couinaud分段中的VII段。V段的门脉分支大多来自右前叶或Ⅷ段门脉的腹侧支。因此,可将右前叶分为腹侧段:Couinaud分段中的Ⅷ段的腹侧段(S8v)和V段(S5)背侧段:Couinaud分段中的Ⅷ段的背侧段(S8d)两个部分。结论新的划分方法不仅有利于肝内病变的精确定位,而且便于肝脏外科实施新的、更安全的术式。     

Anatomical basis for clamping of the right hepatic vein outside the liver during right hepatectomy

The possibility and value of clamping the right hepatic vein (HV) outside the liver during right hepatectomy remain a matter of debate. We carried out an anatomical study on ten fresh cadaveric subjects with no abdominal scarring or hepatic lesions, to determine the biometry of the extraparenchymatous segment of the right HV. One or several accessory right HVs were found in 90% of cases on release of the right edge of the inferior vena cava (IVC). These accessory right HVs had a diameter greater than that of the superior right HV in 10% of cases. In 70% of cases, the extraparenchymatous segment of the vein was free of collateral branches, and in 30% of cases, it was joined by a branch close to its point of exit from the hepatic parenchyma. The length of the vein that can be clamped (length between the point of exit from the hepatic parenchyma and the point of entry of the right HV into the IVC) was 8.6 ± 1.8 mm (6–12). The right HV entered the vena cava, at an acute angle, in 100% of cases. Clamping of the right HV was possible in all cases. Knowledge of these anatomical points makes it possible to isolate an extraparenchymatous segment of the right HV more safely. The right HV can be isolated and clamped outside the liver in more than 80% of cases, making it possible to carry out right hepatectomy on an exsanguinous liver.     

Surgical anatomy of the vasculobiliary apparatus at the hepatic hilum as applied to liver transplantations and major liver resections

Introduction

To evaluate the hepatic arterial, bile duct and portal venous anatomy as applicable to major liver resections.

缝扎肝右、肝中静脉对正常小猪肝脏血流动力学的影响

目的:缝扎健康中国小家猪的肝右、肝中静脉后,了解其对肝脏组织的病理学、血流动力学影响,以探讨临床结扎主肝静脉而保留其肝组织的可行性.方法:将12头中国小家猪随机分为两组,A组6例开腹缝扎肝右静脉及肝中静脉,B组6例为假手术组.应用彩色多谱勒超声观察术前、术后不同时期肝脏血流动力学变化及侧支循环情况,并检测其相应的肝功能及肝脏病理学改变.结果:A组术后1周时肝功能损害明显,以后逐渐恢复,至术后9周时基本恢复正常;缝扎时肝动脉血流速及流量稍下降,约30 min后开始明显升高,3周后达高峰,而门静脉血流速及流量缝扎后即减少,3周降至最低;术后30 min门静脉压力明显升高,后期下降,但仍高于术前;术后1周彩色多谱勒超声可见侧支循环形成.B组手术前后不同时相各指标变化无统计学差异.结论:两支主肝静脉缝扎可引起一过性的肝功能损害;缝扎主肝静脉1周后形成侧支循环.故临床上结扎主肝静脉而保留肝组织是可行的.     

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。     

Clinical anatomy related to the hepatic veins for right lobe living donor liver transplantation

The complexity of liver reconstruction has limited partial right lobe living donor liver transplantation. It is largely due to the difficulty of dealing with the middle hepatic vein. We sought to define the anatomic features of hepatic veins. Forty‐one fresh adult livers, 43 formalin‐fixed adult cadaver livers, and 91 adult liver corrosion casts were used for the study. We determined the number of branches, the maximum diameter, the whole length, the extrahepatic length of the hepatic veins, and the deviation of the middle hepatic vein from the main portal fissure. Nakamura and Tsuzuki's classification of hepatic vein types was used. Type A, B, and C accounted for 59.4, 27.8, and 12.8% of all specimens in this study, respectively. The middle and left hepatic veins formed a common trunk in 60.3% of the specimens, and the length of the common trunk was 1.12 ± 0.62 cm. The degree of deviation to the right of the middle hepatic vein from the main portal fissure was 14.11° ± 12.65°. The frequency of hepatic vein types and the degree of deviation to the right of the middle hepatic vein in this study is markedly different from that reported in other literature. The anatomic features of the hepatic veins in this study suggest that right lobe living donor liver transplantation is more suitable for Chinese. Clin. Anat. 2013. © 2012 Wiley Periodicals, Inc.     

Reconfirmation of the right medial division of the portal venous system of liver

With the development of hepatic surgery and radiology, an increasing amount of researchers have reported discrepancies between the real distribution of the hepatic portal vein branches and Couinaud's segmentation, especially for further division of the right medial division. The present study investigated 25 cadaveric liver dissections and 30 three-dimensional reconstruction images of intrahepatic vessels. The ramifications, course, distribution and quantity of the portal branches were analyzed. An oblique fissure that had few vessels was found among third-order branches of the hepatic portal vein of the right medial division. The right medial division could be redivided into the ventral subsegment and dorsal subsegment by this oblique fissure. A hepatic vein coursed in the oblique fissure between the ventral subsegment and dorsal subsegment. The hepatic vein could serve as an anatomical landmark of the inter-subsegmental plane. This new method of identifying further division of the right medial division is a novel concept providing further information on conventional segmental anatomy.     

Ramification of the portal vein at the porta hepatis in humans

The ramification of the portal vein at the porta hepatis was studied by anatomic dissection performed in 32 formalin fixed human livers. In all the specimens there were branches which ran towards the caudate lobe, arising from the portal vein and either from the left or the right portal branches. Tri-and quadrifurcation of the portal vein was observed. In 5 cases (16%) there were branches arising from left portal branch or portal vein and directed anteriorly to the quadrate lobe or to the region of the gall-bladder sulcus. These branches ranged from 1.0 to 6.0 mm in diameter. The portal caudate branches were divided into 3 groups.Group 1: Branches to the papillary process; 1 or 2 branches in 26 cases (82%), 3 or 5 branches in 3 cases (9%) and no branches in 3 cases (9%);     

肝门静脉右支的临床解剖

目的 探讨肝门静脉右支的形态特征和分支分布规律.方法 50例肉眼观察无病变的成人尸肝进行剥离解剖,对肝门静脉右支的形态结构进行观察,测量主干及主要分支的相关数据并进行统计学分析.结果 82.0%肝门静脉分为左﹑右两支,其成角(105.59±13.82)°,依据右支主干分支将其分为5型,其中65.8%右支主干分为右后叶支...     

肝门静脉解剖和影像三维重建的临床应用

目的 观测门静脉肝内段二级分支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解剖学及影像学资料。 方法 100例无肝病的成人多排螺旋CT（64-MSCT）增强扫描肝门静脉获得数据,利用CT自带的GE ADW 4.5工作站对其进行三维重建,并结合50例成人肉眼无病变尸肝对肝门静脉进行解剖剥离,观测及比较肝门静脉分支规律并采集相关数据进行统计学分析。结果 影像重建和大体解剖的近第1肝门处肝门静脉内径分别为（11.20±1.48）mm和（10.86±2.01）mm;左、右支主干夹角分别为（93.58±24.03）°和（105.59±13.82）°;左支横部长分别为（29.50±6.51）mm和（23.90±5.29）mm,中点内径分别为（7.70±1.55）mm和（7.43±1.09）mm;右支主干长分别为（21.77±10.35）mm和（20.63±6.59）mm;中点内径分别为（9.10±1.66）mm和（9.26±1.77）mm。依据肝门静脉的分支情况可将其分为4型。结论 肝门静脉变异情况并不少见,其分支的直径与夹角等均存在一定的变化,在肝外科手术实施时,对门静脉主干分支各型应给予高度的重视。     

Right ligamentum teres joining to the right branch of the portal vein

Ligamentum teres joining to the right branch of the portal vein in a 79-year-old Japanese male cadaver was noted during student dissection at Kumamoto University in 2004. The ligamentum teres entered the liver along the left side of the gallbladder fossa. The quadrate lobe was not distinguished from the left lobe in the visceral surface. When the liver parenchyma was removed by tearing off to expose the branches of the portal and hepatic veins, it was clarified that the ligamentum teres unusually joined to the bifurcation of the upper anterior and lower anterior branches of the right branch of the portal vein. The ligamentum teres is the remnant of the umbilical vein working throughout fetal life. Initially a pair of the umbilical veins entered the sinus venosus. During the fourth and fifth weeks they connect to the hepatic sinusoids, which become the portal and hepatic veins, and the parts entering the sinus venosus of both umbilical veins disappear. By the eighth week, as all remainder of the right umbilical vein disappears, the left umbilical vein is the only one to carry blood from the placenta to the liver. It results in the ligamentum teres joining to the left branch of the portal vein. However, in the present case it is thought that the right umbilical vein remained instead of the left one for some reason, and it then became the right ligamentum teres joining to the right branch of the portal vein.     

Arterial supply and biliary drainage of the dorsal liver: A dissection study using controlled specimens

Liver surgeons favor using the entity called the 'dorsal liver' (i.e. the caudate lobe and other paracavally located liver parenchyme of segments 7 and 8). According to minute dissection of 48 livers, we describe the territories of the left/right portal veins, hepatic ducts and hepatic arteries in the dorsal liver. In the caudate lobe, the right hepatic artery, rather than the left hepatic artery (23/48 vs 19/48 for right vs left, respectively), tended to supply the 'left' portal vein territory. Similarly, paradoxical drainage patterns, such as the right hepatic duct draining the left portal vein territory, were found in seven of 48 livers. In the territory of the hilar bifurcation, right hepatic artery dominance was also evident and various bile drainage patterns were found. These included double drainage by the bilateral hepatic ducts (3/48) and drainage into the confluence of bilateral ducts (6/48). In contrast, the arterial supply and biliary drainage of the paracavally located parenchyme of segments 7 and 8 usually depended on the proper segmental arteries and ducts and their variations were within the range of those found in other parts of the right lobe. Therefore, the dorsal liver concept may not be anatomical but, rather, simply aimed at usefulness in surgery. Nevertheless, clear subdivision of the caudate lobe according to biliary drainage and/or arterial supply seemed difficult because of the paradoxical relatioships among the portal vein, hepatic artery and bile duct. Consequently, the present results support extended surgery based on the dorsal liver concept for carcinomas involving the caudate lobe.