牛肝门静脉系统和肝静脉系统

以铸型方法及实体解剖观察了牛肝内门静脉分支和肝静脉的属支,发现牛门静脉的分支与人、猪、兔、羊等相似。门静脉左支发出左个侧叶背、腹侧静脉、左内侧叶内、外侧静脉、尾状叶支组和方叶支组;右支发出右内侧叶静脉、右外侧叶静脉及尾状突静脉。肝大静脉有肝左、肝中、肝右静脉三支。与兔、猪、羊的肝大静脉相比,牛肝脏愈合的程度要明显。此外,对血管分支的名称、肝内分部、尾状突肝静脉的位置、牛肝的外形分部作了讨论     

兔肝内管道研究

兔肝内门管鞘系统所包含的门静脉分为左、右２支：左支供应左内叶、左外叶、右内叶及尾状叶，左外叶静脉可分出背、腹侧静脉，左内叶静脉及右内叶静脉各分出内、外侧静脉，尾状叶的静脉也分出左、右侧静脉；右支供应右外叶，分出右外叶静脉和右叶间静脉，右外叶静脉分出背、腹侧静脉。与人肝相似，兔肝内部也分为左、右２叶及左外段（叶）、左内段（叶）、右外段（叶）、右内段（叶）４段，尾状叶的左、右侧部分别隶属于左、右叶。兔肝的外形可分为左外叶、左内叶、右外叶、右内叶、尾状叶及位于胆囊左侧、门静脉左支横部腹侧及方叶支分布区的方叶。肝动脉和胆管的分支与门静脉的相应支伴行，但其分支形式较复杂。兔的肝静脉系统，除肝中静脉外，汇集各叶血液的肝大静脉还有左外叶肝静脉、左内叶肝静脉、右内叶肝静脉、右外叶肝静脉及尾状叶肝静脉，肝小静脉很少。     

猪肝内管道研究

猪肝内管道及其叶、段划分与人肝基本一致，全肝可分为左、右二叶，它们各又分为内、外侧叶（或称内、外侧段），方叶属于左内叶。外形上的尾状叶以中裂为界分为左、右二部，分别隶属于左、右叶。各叶、段由同名的门静脉分支、肝动脉分支供应血液，它们分别为左外叶动、静脉，左内叶动、静脉、右内叶动、静脉、右外叶动、静脉及走向尾状叶左、右二部的尾叶支。胆汁由同名肝管汇流。     

家禽肝门静脉系统

以铸型方法观察了家禽肝门静脉的分支。其中，鸡有左、右肝门静脉各１支，左叶有左外叶颅侧支、左外叶尾侧支和左内叶支，右叶有右叶颅侧支及右叶尾侧支；鹅、鸭则有左肝门静脉２支，右肝门静脉１支。左叶有左外叶颅侧支和左外叶尾侧支，右叶有右叶颅侧支和尾侧支。左、右肝门静脉于横部汇集，并向颅侧及尾侧发出许多分支。此外，还强调和讨论了家禽肝门静脉系统在分布上的一些特点     

山羊肝内门静脉的分支与分布

采用肝门静脉内灌注６０％硫酸钡火棉胶液，通过改变投照角度方法摄取肝脏的背腹位、侧位和４５°斜位Ｘ线片，观察了３０只山羊肝内门静脉的走向、分支和分布。结果表明：（１）山羊门静脉进入肝门后恒定地分为左右２条主干。右干短，０．５～１．５ｃｍ。左干长，３．７３～４．９７ｃｍ。左干在左叶上端与叶间切迹之间形成一弧部。它相当于人肝门静脉左干的角部、矢部和囊部。少数肝脏弧部不明显或缺如。（２）各肝叶的门静脉分支分布类型可归纳为：左叶８种类型，右叶７种类型，方叶和乳头突各６种类型，尾状突５种类型。（３）按门静脉各肝叶支的分支密度排列则依次为左叶＞右叶＞方叶＞尾状突＞乳头突。（４）少数门静脉肝叶支的细分支之间出现了孤立吻合支     

哺乳动物的肝静脉系

在分叶明显的肝脏，每叶均有肝静脉汇集其静脉血。左内侧叶和右内侧叶之间发生愈合的肝脏，其间出现肝中静脉。马属动物方叶与右叶之间有较深裂隙，肝中静脉缺如。愈叶程度高的肝脏（牛、羊），主要肝静脉仅为左、中、右三支，故肝静脉的数量与愈合相关。国际兽医解剖学名词（Nomina Anatomica Veterinaria,N.A.V.)的相关第目是不合适的，应予补充。     

山东黄牛肝胆管系统的研究

本研究通过对１５例山东黄牛肝脏标本的观察和测量表明：其肝外胆管系统的组成和方位恒定；并探讨了黄牛肝外胆道外科的最佳途径。对１３例肝乳胶铸型标本的研究，提示了黄牛肝内胆管树的基本类型：肝左管分出两支Ⅱ级胆管进入左叶，一支Ⅱ级胆管进入方叶，一支Ⅲ级胆管进入尾状叶；肝右管分出三支Ⅱ级胆管进入右叶，还有一些细胆管进入方叶和尾状叶。     

猪的肝静脉系统

猪的肝静脉系统包括肝大静脉和肝小静脉。肝大静脉主要汇集左内叶、左外叶、右内叶和右外叶的血液，尾状叶的血液主要由肝小静脉回流。左外叶、左内叶和右内叶的血液常有专支汇集，它们是左外叶肝静脉、左内叶肝静脉和右内叶肝静脉；汇集右外叶的静脉有３～４支，可总称为右外叶肝静脉。此外，在相邻２叶之间常有叶间静脉，它们是左叶间肝静脉、肝中静脉和右叶间肝静脉。由于猪的叶间切迹深，左、右叶间肝静脉主要汇集左外叶及右外叶的血液，故可分别归属于左外叶肝静脉和右外叶肝静脉；肝中静脉发达，且恒定存在于中裂内，汇集左内叶和右内叶内侧部的血液。     

犬肝脏疾病的发病原因与治疗

犬肝脏大部分位于肋弓内侧,在胃和膈肌之间,被分为7个肝叶,分别为乳头突、左外叶、左内叶、方叶、右内叶、右外叶、尾状叶,左侧后缘通常与脾脏接触,右侧尾状叶可以延伸到右肾处.右侧最后肋骨的后方,拇指在前上方压可以触摸到肝脏,肝脏疾病时,可感知到肝脏肿大.     

屠宰中猪肝常见的病理变化与处理

肝脏是猪体内最大的腺体，具有分解、合成、贮存营养物质和解毒以及分泌胆汁等作用。猪的肝脏发达，重1—2．4kg。占体重的1．5％～2．5％，呈红褐色，中央部分厚，边缘薄，壁面隆凸，脏面凹。以三个深的切迹分为左外叶、左内叶、右内叶和右外叶。右内叶又以肝门分为尾叶和方叶。     

Three-dimensional vasculature of the bovine liver

To clarify anatomical distribution of Fasciola infection, the vascular and ductal architectures of the liver were studied by means of corrosion cast technique using synthetic resin. The arteria hepatica propria (AP) passes as the arteria gastroduodenalis (AG); AP becomes the left trunk after the porta hepatis; AP passes on the right side of vena porta communis (VPC) and projects AG while curving in a U-shape below the portal vein. Hepatic veins located between the vena hepatica media (HM) and vena hepatica dextra (HD) varied widely among specimens and were irregular, including the vena hepatica dorso-lateralis sinistra (Hds), vena hepatica dorso-lateralis dextra (Hdd), vena hepatica lobi caudati (Hlc), venae hepaticae processus caudati (Hpc), venae hepaticae processus papillaris (Hpp), and the hepatic vein to the dorsal intermediate part, which directly or indirectly drained into the vena cava caudalis. The courses of the bovine hepatic veins were markedly diverse, and anastomoses between vena hepatica sinistra (HS) and Hds were observed in about a half of the livers. The portal vein entered the liver as VPC slightly above the centre of the right lobe on the visceral surface. The intermediate or transverse part [pars transversa trunci sinistri (PTS)] of truncus sinister (TS), which extends from the entry of the portal vein into the left lobe of the liver, was slightly arched downward [pars umbilicalis trunci sinistri (PUS)]. The portal vein further arched from the distal end of TS to the umbilical vein and ran towards the inter-lobar incision between the left lobe and quadrate lobe. Based on these branches, hepatic segments were determined as 13 or 14 areas. A total of 15 bile ducts were derived from various lobes. The hepatic duct was about 2.6-6 cm long from the confluence of the right and left hepatic ducts to the division of the cystic duct and the common hepatic duct.     

Pathological features of hepatic portal venous gas in a cat

An 8-year 8-month-old castrated male Munchkin presented with vomiting, anorexia and hypoactivity. Computed tomography revealed excessive gas accumulation within the intestinal lumen and gas bubbles in the liver, spleen, and portal venous system, indicating hepatic portal venous gas. The cat died without any significant improvement, and mild splenomegaly was found at necropsy. Histologically, multiple gas vacuoles were diffusely observed in the liver and spleen. In the stomach, multiple gas vacuoles and scattered focal ulcers were detected within the mucosa. Multifocal hemorrhage was noted in the small and large intestines, whereas gas vacuoles were not present. Based on these findings, a gastric ulcer under high gas pressure may have provided an entry point for gas into the portal venous system.     

ACQUIRED PORTAL COLLATERAL CIRCULATION IN THE DOG AND CAT

We describe patterns of acquired portal collateral circulation in dogs and in a cat using multidetector row computed tomography angiography. Large portosystemic shunts included left splenogonadal shunts in patients with portal hypertension. Small portal collaterals were termed varices; these collaterals had several patterns and were related either to portal vein or cranial vena cava obstruction. Varices were systematized on the basis of the venous drainage pathways and their anatomic location, namely left gastric vein varix, esophageal and paraesophageal varices, gastroesophageal and gastrophrenic varices, gallbladder and choledocal varices, omental varices, duodenal varices, colic varices, and abdominal wall varices. As reported in humans and in experimental dog models, esophageal and paraesophageal varices may result from portal hypertension that generates reversal of flow, which diverts venous blood in a cranial direction through the left gastric vein to the venous plexus of the esophagus. Blood enters the central venous system through the cranial vena cava. Obstructions of the cranial vena cava can lead to esophageal and paraesophageal varices formation as well. In this instance, they drain into the azygos vein, the caudal vena cava, or into the portal system, depending on the site of the obstruction. Gallbladder and choledocal varices, omental varices, duodenal varices, phrenico-abdominal varices, colic varices, abdominal wall varices drain into the caudal vena cava and result from portal hypertension. Imaging plays a pivotal role in determining the origin, course, and termination of these vessels, and the underlying causes of these collaterals as well. Knowledge about these collateral vessels is important before interventional procedures, endosurgery or conventional surgery are performed, so as to avoid uncontrollable bleeding if they are inadvertently disrupted.     

ANGIOGRAPHY OF THE HEPATIC AND PORTAL VENOUS SYSTEM IN THE DOG AND CAT: AN INVESTIGATIVE METHOD*

The investigators studied the hepatic angiographic technics used in human medicine with respect to their applicability for the investigation of circulatory liver diseases in the dog and cat. The technics were performed in 11 normal dogs and 2 normal cats, and the normal radiographic anatomy of the hepatic portal system and its tributaries was described. The potential indications for the angiographic technics were defined and their respective advantages and disadvantages discussed. Splenoportography was a valuable method for outlining the intrahepatic portal vein branches and for percutaneous prehepatic portal vein pressure determination. Percutaneous transhepatic portography was more difficult to perform, but it provided better detail of the intrahepatic portal veins than splenoportography. Transjugular transhepatic portography was the most versatile but also the most cumbersome of all technics tested. Percutaneous kinetic hepatography proved impractical in dogs and cats. The mesenteric tributaries to the hepatic portal system were best outlined by cranial mesenteric arterial portography or by operative mesenteric venous portography. Operative mesenteric venous portography, in contrast to cranial mesenteric arterial portography, was also useful for prehe-patic portal vein pressure determination. Free and wedged hepatic venography provided an opportunity for the functional and morphologic investigation of the hepatic sinusoid circula-tion.     

ANATOMY OF THE PORTAL AND HEPATIC VEINS OF THE DOG: A BASIS FOR SYSTEMATIC EVALUATION OF THE LIVER BY ULTRASONOGRAPHY

The objective of this study was to define, in detail, the anatomy of the portal and hepatic veins in the dog in order to establish a procedure for the systematic evaluation of the liver by ultrasonography. Anatomical details were obtained from the formalin fixed livers of ten dogs. The hepatic and portal veins were removed intact from these livers so that a detailed pattern of distribution could be established and the numbers of branches could be counted. Silastic casts were also made of the hepatic and portal veins of two livers, one in situ and one in which it had been removed. The former was to enable the relationship of the portal to the hepatic veins to be established as closely as possible within the animal and the other to provide a model of the distribution of each venous system within the liver. Contrast medium was infused into two other livers and radiographs taken to establish the relationship of each branch to each lobe. It was found that there was a consistent pattern of venous branching to each lobe of the liver in the dog with little variation between individual specimens. All liver lobes contained definite venous branches so that the left lateral and medial, quadrate, right medial and lateral, caudate and papillary veins could be distinguished in each venous system. We believe that an appreciation of this venous distribution will aid in the systematic evaluation of the liver during ultrasonography by enabling identification of each liver lobe. It should be of value for differentiating portal from hepatic veins and veins from dilated bile ducts.     

NONINVASIVE ESTIMATION OF CENTRAL VENOUS PRESSURE IN ANESTHETIZED DOGS BY MEASUREMENT OF HEPATIC VENOUS BLOOD FLOW VELOCITY AND ABDOMINAL VENOUS DIAMETER

Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B‐mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B‐mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a‐, S‐ and v‐wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v‐wave velocity (0.823), S‐wave velocity (?0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v‐wave velocity (r=0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.     

Influence of administration route on the biotransformation of amoxicillin in the pig

A comparison was made in the plasma concentration of the major metabolites of amoxicillin (AMO), i.e. amoxicilloic acid (AMA) and amoxicillin diketopiperazine-2',5'-dione (DIKETO) in portal and jugular venous plasma after oral (p.o.) and intravenous (i.v.) AMO administration to pigs, in order to study a possible presystemic degradation of AMO in the gastro-intestinal tract and liver. Almost identical plasma concentration-time curves were obtained for AMO and its metabolites in portal and jugular venous plasma, both after p.o. and i.v. AMO administration. Almost immediately after i.v. AMO administration, high AMA and DIKETO concentrations were measured in plasma, while after p.o. dosing, the metabolites appeared in plasma after almost complete absorption of AMO. No significant differences in pharmacokinetic parameters of AMO, AMA and DIKETO, derived from the concentration-time profiles in portal and jugular venous plasma were calculated, both after i.v. and p.o. AMO administration ( P  > 0.05). After p.o. administration, the half-life of elimination ( t _1/2(el)) for AMA is at least two or three times the t _1/2(el) of AMO (0.75 h for AMO vs. 2.69 h for AMA), indicating the slower clearance of the metabolite. It could be hypothesized that AMA is only eliminated by glomerular filtration, as its open β-lactam structure might not be recognized by the transport carrier in the proximal tubule of the kidney. The results of the study indicate that AMO is not substantially metabolized presystemically in the gut and liver. Therefore, it may be assumed that the kidney may be the major organ for AMO biotransformation. Future in vivo and in vitro experiments should be performed to state this hypothesis.     

Gross Anatomy of the Canine Portal Vein

The gross anatomy of the portal vein of 21 dogs was studied by venous portography, corrosion casting, and gross dissection. The portal vein in all specimens originated by confluence of the cranial and caudal mesenteric veins. Its large tributaries were the splenic and gastroduodenal veins, which entered the portal vein between its origin and the hepatic porta. At the hepatic porta, the portal vein divided into a short right branch and a larger left branch. The right branch ramified in the caudate process of the caudate lobe and in the right lateral lobe of the liver. The left branch was essentially the continuation of the portal vein from which successive branches passed to each of the remaining lobes of the liver and the papillary process of the caudate lobe.