Liver Anatomy Part 1 Son 2111 PDF

LIVER ANATOMY PART 1 SON 2111 Professor Carrie H. Hall Chapter 5 - from Diane Kawamura  LIVER FUNCTION Main Job filter blood coming from digestive tract Detoxifies chemicals Metabolized drugs Secretes bile ends up back in intestines Makes p...

LIVER ANATOMY PART 1 SON 2111 Professor Carrie H. Hall Chapter 5 - from Diane Kawamura  LIVER FUNCTION Main Job filter blood coming from digestive tract Detoxifies chemicals Metabolized drugs Secretes bile ends up back in intestines Makes proteins important for blood clotting and other functions  EMBRYOLOGY FETAL CIRCULATION Umbilical vein carries oxygenated blood from placenta to fetus Ascends fetal abdomen- courses toward liver (Paraumbilical vein-Portal sinus) Portion bypasses liver via ductus venosus AFTER BIRTH Both Veins Close and exist as LIGAMENTS Ligament Teres remnant of umbilical vein Runs from umbilicus to left portal vein After birth umbilical vein contracts down forming Lig Teres With portal hypertension Lig Teres recanalizes to for, portosystemic venous collateral Ligamentum Venosum- remnant of ductus venosus Runs from left portal vein to IVC separating the left lobe liver from the  EMBRYOLOGY FETAL CIRCUL ATION DIRECTION OF FETAL CIRCUL ATION Ductus Umbilical Venosus Left Portal Vein (Lig. IVC Vein (Lig. Teres) Venosum)  LIVER LOCATION Right Hypochondrium Epigastrium Extends at variable degrees based on size and shape into left hypochondrium Lateral left segment and length of right determine contour and shape Described as Irregular Hemispheric Wedge shaped  LIVER SIZE Size by US can be difficult and subjective Limited FOV & measuring techniques Measured superior-inferior at the MID-CLAVICULAR sagittal OR coronal MID-AXIAL plane  LIVER SIZE Hepatomegaly is indicated in 75% of patient population with greater than 15.5cm superior-inferior dimension Can be caused by infection, hepatic tumors, congenital, or metabolic disorders. Hepatitis, polycystic liver disease, NAFL- nonalcoholic fatty liver, Reidel’s lobe Reidel’s lobe – inferior projection of right lobe Can be mistaken for hepatomegaly when viewing the superior-inferior dimension of the liver.  LIVER ANATOMY 3 LOBES Right, Left, Caudate (Quadrate is the medial aspect of the left lobe) Divided based on Portal and Hepatic Vein distribution To describe the liver anatomy- Nomenclature highly variable and has changed over time we will use functional liver Parts anatomy and describe it as a first order Halves second order Lobes third order Divisions On the next slides Sectors Segments Subsegments Present day anatomists, surgeons, and radiologists all use different terminology to classify Liver  -L IVE R A N AT OM Y- FIR S T OR D E R D IV IS ION P ORTAL VE I N B RA N C H IN G R IGH T & L E FT P ORTA L B RA N C H IN G LOBAR / HEMILIVER ANATOMY RIGHT & LEFT HEPATIC LOBES Divided by a plane between the Gallbladder and the IVC This Plane marks the Division of MAIN PORTAL VEIN into its RIGHT and LEFT branches A, B, C TRV image show division of the right and left lobes The plane goes throw the IVC, MHV, GB, the RPV & LPV bifurcation  -LIVER ANATOMY- SECOND ORDER DIVISION PORTAL VEIN BRANCHING 4 PARTS (SEGMENTS) DIVIDED BY 3 HEPATIC VEINS Sector/Segmental Anatomy Right & Left Lobes further divided by hepatic veins into four separate parts 4 segments = second order division or second branching of portal veins Left Lateral = Segments II & III Left Medial = Segments IVa & IVb Right Anterior = Segments V & VIII Right Posterior = Segments VI & VII Right lobe- supplied by right portal vein Left lobe- supplied by left portal vein Caudate lobe – receives branches from right and left portal vein  - L I V E R A N AT O M Y- THIRD ORDER DIVISION P O RTA L V E I N B RA N C H I N G 8 SEGMENTS Segments / Subsequent Anatomy Hepatic veins divide the liver longitudinally/ vertical into 4 parts/segments Portal veins divide liver transversely (horizontal plane) creating 8 segments (imaginary plane at the MPV level divide into Right and Left Portal Vein Segment I = Caudate Lobe Segment II = Left Lateral Superior Segment III = Left Lateral Inferior Segment IVa = Left Medial Superior Segment IVb = Left Medial Inferior Segment V = Right Anterior Inferior Segment VI = Right Posterior Inferior HEPATIC VEINS & PORTAL VEINS  INTERSEGMENTAL / INTRASEGMENTAL VESSELS Intersegmental – HEPATIC VEINS Hepatic veins course between the lobes and segments- interlobar & intersegmental Hepatic veins = NO echogenic walls Intrasegmental – PORTAL VEINS Vessels of the portal triad course to the center of each segment – intrasegmental Portal triad encased by Glisson’s capsule- fibrofatty sheath giving it = hyperechoc walls Portal triad = main portal, proper hepatic artery, common hepatic duct  LIVER BLOOD SUPPLY Liver receives DUAL blood supply 1. Hepatic arterial blood is oxygen rich 25% of blood supplied to liver 2. Portal venous blood nutrient rich after it leave walls GI tract 75% of blood supplied to liver Blood from portal vein and hepatic arteries mixes in liver sinusoids Hepatic veins drain blood into IVC  HEPATIC ARTERY Common hepatic artery branch off celiac axis Hepatic artery to left of CBD Anterior to left portal vein and main portal vein Proper hepatic artery is continuation and terminates into right, middle and left Caudate lobe receives from the right and left branches Cystic artery arises from the right hepatic artery Doppler demonstrates low-resistance waveform normal hepatic artery Post-operative liver transplant= high resistive hepatic artery suggest venous congestion of liver or possible organ rejection Parvus tardus hepatic artery= suggest proximal anastomotic stenosis Low resistive spectral tracing of hepatic artery. Sometimes zooming up image aids in better seeing small hepatic artery.  PORTAL VEIN MPV originates to right midline at junction of splenic vein and SMV Course superior toward porta hepatis Divides into LPV & RPV Color Doppler is used to screen for direction of blood flow HEPATOPETAL= flow toward liver HEPATOFUGAL= flow away from liver Should be low velocity-continuous flow toward the liver *flow can increase after eating PV size – 13mm is upper limits (range is 6-15mm) MPV anterior to IVC and superior to panc head Spectral Doppler tracing of the main portal vein showing continuous forward flow (hepatopetal).  HEPATIC VEINS Drain into superior aspect of IVC RHV, MHV, LHV Scanning anterior abd surface Color Doppler shows blood flow toward the IVC and away from the Transducer Triphasic waveform reflects right atrial filling- contraction- relaxation Spectral Doppler tracing of the middle hepatic vein showing normal hepatofugal triphasic, flow.  HEPATIC LIGAMENTS Coronary Ligament- connect posterior-superior liver surface to the diaphragm Anterior and posterior layers Highly reflective when visualized and suspends liver from diapghram Surround the bare area Continuous on each side of the = right & left triangular ligaments and anteriorly with falciform lig Right & Left Triangular Ligament- Formed by upper and lower ends of coronary ligaments (Right) Highly reflective when visualized and seen to the far right and left of bare area  HEPATIC LIGAMENTS Ligamentum Teres- (round ligament)- Remnant of the umbilical vein extending from umbilicus to the left portal vein Recanalizes in cirrhosis to function as a venous collateral Highly reflective, appears round or as a triangular shape Falciform Ligament- Highly reflective when visualized Broad thin anterior-posterior fold of the parietal peritoneum Separates right and left lobes on anterior surface  LIVER LIGAMENTS Transverse: In patients with ascites, falciform ligament (arrow) can be identified coursing between the anterior abdominal wall and the left lobe of the liver (LLL). Transverse: Ligamentum teres (small arrows) is seen in midlower left lobe of the liver; it serves as a landmark separating the medial segment (MSLL) and the lateral segment (LSLL) of the left lobe. The ligamentum teres should not be mistaken for a liver lesion. MLF—main lobar fissure.  LIVER ECHOGENICITY Normal Liver Homogeneous Slightly hyperechoic compared to normal renal cortex Compare signal amplitudes between structures HYPERecho HYPOechoi ic c Renal Pancreas Spleen / Renal Sinus LIVER Cortex  LIVER PHYSIOLOGY Liver is essential to life performing >500 separate activities. Single liver cell diverse activities analogous to: Factory for many chemical compounds Warehouse with short- and long-term storage capabilities Power plant producing heat Waste disposal plant excreting waste Scientist is able to regenerate tissue not too severely damaged  LIVER PHYSIOLOGY Three types of cells carry out these functions: Hepatocyte in parenchyma Most abundant cell carries out most metabolic functions Biliary epithelial cells Line biliary system, bile ducts, canaliculi, gallbladder Kupffer cells Phagocytic Belong to the reticuloendothelial system Line the sinusoids Hepatic diseases alter these functions and produce identifiable clinical manifestations  LIVER FUNCTION TESTS Aspartate Aminotransferase (AST) AST = SGOT Present in liver, heart, skeletal muscle, kidney and brain Increase by itself is NON-SPECIFIC for liver disease Known for being very sensitive and elevated in almost all significant hepatocellular disease Increase in AST withOUT ALT- seen with myocardial infarction, heart failure, muscle injury, CNS disease on other non-hepatic disease. AST & ALT elevated some in almost all liver diseases- highest usually with viral hepatitis Alanine Aminotransferase (ALT) ALT= SGPT ALT more specific for LIVER DISEASE than AST Present in high levels within liver tissue Elevated AST and LDH with a normal ALT rules out hepatic disease  LIVER FUNCTION TESTS Gamma Glutamyl Transpeptidase (GGT) Present in hepatocytes & bile duct epithelium Increased indicates hepatocellular disease & biliary obstruction Increased in most diseases with acute damage to liver & bile ducts Increased in patients with acute and chronic alcohol abuse GGT + ALP = Biliary obstruction GGT + ALT = Hepatocellular disease Lactic Dehydrogenase (LDH) Enzyme found in cells of many body tissues- cellular damage causes elevation to total serum LDH LDH4 & LDH5 found in liver and can be found with cirrhosis and chronic viral hepatitis  LIVER FUNCTION TESTS Alpha Fetopretein (AFP) Protein synthesized by fetal liver and levels decrease during first year of lfe Elevated with Hepatocellular carcinoma HCC Germ cell tumors – testes & ovaries Metastatic liver disease Hepatoblastoma in children Platelets Contributes to hemostatis ( process of stopping bleeding at the site of interrupted endothelium) Low platelet concentration = thrombocytopenia Elevtaed platelet concentration = thrombocytosis- congenital, reactive or unregulated production  LIVER FUNCTION TESTS Prothrombin Time (PT) Clotting factor- due to liver dysfunction or absence of vitamin K Used to helped diagnose cause of unexplained bleeding or inappropriate blood clots INR is the international normalized ratio- used to monitor patients on blood thinners such as Warfarin or Coumadin Partial Thromboplastin Time (PTT) Characterizes blood coagulation apart form detecting abnormalities in clotting factor. Used to monitor patients on Heparin PT, INR, PTT and Platelets are all monitored prior to an invasive procedure to ensure proper Clotting Factors  TUMOR MARKERS Hepatocellular carcinoma AFP Germ cell tumors Calcitonin Medullary Thyroid Cancer Testicular cancer Germ Cell Tumor HCG Testicular cancer CA-15-3 & Breast Cancer CA 27-29 PSA Prostate Cancer Ovarian cancer CA 125 Uterine cancer Lung Cancer Lactate Gastrointestinal cancer Dehydrogenase Germ cell tumor Gastric Cancer CA 72-4 Ovarian Cancer Alkaline Bone cancer Colorectal Cancer Phosphatase Liver disorders Colorectal cancer, Lung cancer, Thyroid Pancreatic Cancer, Lung cancer Cancer Cholangiocarcinoma, Colorectal CEA- Bile duct cancer, Bladder Cancer, Uterine CA 19-19 Cancer Carcionoembryon cancer Gastrointestinal Cancer Breast cancer. Gastrointestinal cancer, ic Antigen Esophageal cancer