Left umbilical v. carries blood from placenta to foetus. Ductus venosum shunts blood form the left umbilical vein to the IVC in the foetus bypassing the liver.
Even older anatomy Falciform ligament anteriorly and lig. teres and venosum on visceral surface Caudate and quadrate lobe considered to be part of right lobe
Hepatic a. carries oxygenated blood and conducted to central v of each liver lobule Portal v carries venous blood containing products of digestion absorbed from the GI tract.
Areas drained by hepatic ducts are the same as those supplied by the accompanying portal v. and hepatic a. Choledochal sphincter surrounds the bile duct as it penetrates the duodenal wall Hepatopancreatic sphincter (sphincter of Oddi) at distal end of hepatopancreatic ampulla controls release of both bile and pancreatic fluid
Liver, biliary system, pancreas and spleen
Anatomy of the liver,pancreas and portal system Surgical case discussion Antonio Manzelli MD MSc PhD Upper GI and HPB Consultant
Embryology of the digestive glands Liver, gallbladder and pancreas develop from endodermal diverticulae that bud from the duodenum in the 4th to 6th weeks Liver sprouts first and expands in ventral mesentery Cystic diverticulum also in ventral mesentery Pancreas arises from a dorsal and ventral bud. Ventral pancreatic bud migrates posteriorly to fuse with the dorsal bud. Main duct of ventral bud becomes the main pancreatic duct.
Liver Largest gland in the body (1.5 Kg) Lies in right upper quadrant. Underlies the thoracic cage. Conforms to right dome of diaphragm Connected to the diaphragm by the falciform and coronary ligaments
Liver Functions Exocrine (digestive) functions:1. Synthesizes and secrets bile salts2. Secrets into the bile a bicarbonate-rich solution Endocrine functions:1. Secrets insulin-like growth factor I (IGF-I)2. Contributes to the activation of vitamin D3. Metabolizes hormones4. Secretes cytokines involved in immune defenses
Liver Functions Clotting functions: -Produces many of the plasma clotting factors Plasma protein -Synthesizes and secretes plasma albumin
Liver FunctionsOrganic metabolism Converts plasma glucose into glycogen Converts plasma amino acids to fatty acids Synthesizes triacylglycerols and secrets them as lipoproteins Produces glucose from glycogen (glycogenolysis) Converts fatty acids to keones during fasting Produces urea
Liver Functions Cholesterol metabolism 1. Synthesizes cholesterol and releases it into the blood 2. Secretes plasma cholesterol into the bile 3. Converts plasma cholesterol into bile salts Excretory function: 1. Secrets bilirubin and other bile pigments into the bile 2. Destroys old erythrocytes
At laparotomy the liver is divided by the umbilical fissure and falciform ligament into a larger ‘right’ lobe and a smaller ‘left’ lobe
Liver - relations Surfaces separated by inferior border of liver and coronary ligament posteriorly Bare area between the reflections of coronary ligaments in direct contact with diaphragm and not covered by peritoneum Diaphragmatic surface Smooth and convex Separated from diaphragm by subphrenic recess
Liver – relations (2) Visceral (posteroinferior) surface Lies in contact with oesophagus, stomach and lesser omentum on the left Duodenum in midline Right kidney, adrenal and hepatic flexure of the colon on the right H-shaped arrangement of structures Crossbar formed by porta hepatis (portal vein, hepatic artery, hepatic ducts, nerve plexus and lymph vessels Left: ligamentum teres (remnant of left umbilical v.) and ligamentum venosum (remnant of ductus venosum)
Liver - old lobar anatomy Right and left lobes divided by plane through the IVC and gallbladder fossa Caudate lobe Lies posteriorly between lig. venosum and IVC fossa Porta hepatis inferiorly Tail-like caudate process connects to right lobe and separates portal vein from IVC Quadrate lobe Anteroinferior between GB bed and lig. teres Porta hepatis superiorly Caudate and quadrate lobe considered to be part of left lobe Reidel’s lobe (not a true lobe) Lower border of the right lobe lateral to the GB may project downwards for a considerable distance as a broad or bulbous process Occurs in 5-10% of females and rarely in males
Liver - segmental anatomy (Couinaud system) Knowledge of segments important in the assessment of location and extent of hepatic pathology as surgery is performed in segmental fashion and distribution of disease determines whether lesions are resectable. The hepatic veins divide the liver into 4 divisions A horizontal plane through the portal vein divides the 4 divisions into superior and inferior segments Segments numbered in clockwise direction starting at caudate lobe (segment 1)
Liver - vascular anatomy Double blood supply from hepatic artery (30%) and portal vein (70%) Arterial supply by common hepatic artery branch of coeliac artery. Gives off right gastric and gastroduodenal arteries before reaching the liver in the free edge of the lesser omentum. Divides into left and right hepatic arteries before entering the liver at the porta. Variants of right hepatic artery below Portal vein formed posterior to neck of pancreas by union of SMV and splenic vein
In approximately 25% of individuals, theright hepatic artery arises partially orcompletely from the superior mesentericartery (A, C, E), and in a similar proportionof patients, the left hepatic artery may bepartially or completely replaced by a brancharising from the left gastric artery andcoursing through the gastrohepaticomentum to enter the liver at the base ofthe umbilical fissure (D, F). Rarely, the rightor left hepatic arteries originateindependently from the celiac trunk orbranch after a very short common hepaticartery origin from the celiac (B, C). Thegastroduodenal artery may originate fromthe right hepatic artery (B, C).
The portal vein is formed behind the neck of the pancreas byconfluence of the superior mesenteric and splenic veins
Biliary and vascularanatomy of the left liver.Note the position ofsegment III duct abovethe corresponding veinand its relationship tothe recessus of Rex.Biliary and vascularanatomy of the rightliver. Note the horizontalcourse of the posteriorsectoral duct and thevertical course of theanterior sectoral duct.
Liver - vascular anatomy (2) Right and left lobes functionally independent and defined by arterial distribution Each supplied by left and right portal v., left or right hepatic arteries and drained by left or right hepatic duct (portal triad) Quadrate lobe supplied by left hepatic artery Caudate lobe supplied by both
Liver - hepatic veins Hepatic veins are intersegmental and do not run with the structures of the portal triad Right, middle and left hepatic veins drain corresponding thirds of the liver Middle hepatic vein lies in the principal plane between right and left lobes Left hepatic vein lies between medial and lateral segments of the left lobe Right hepatic vein lies between anterior and posterior segments of the right lobe All drain into the IVC without an extrahepatic course Inferior group of small veins from right lobe also drains into IVC
Liver – Lymph drainage and innervation Lymph drainage Superficial and most deep lymph vessels converge at the porta and end in the hepatic lymph nodes (eg. Cystic LN near GB neck or LN of omental foramen) Hepatic LN’s drain into coeliac LN’s around the coeliac trunk, then thoracic duct Some deep lymph vessels follow hepatic veins to IVC foramen in diaphragm and end in middle phrenic LN’s Innervation Sympathetic and parasympathetic supply from the hepatic plexus, a derivative of coeliac plexus (formed from fibres of left and right vagus and right phrenic nerves)
Terminology of Liver Anatomy and Resections: The Brisbane 2000 TerminologyIn 1998 at its meeting in Berne, Switzerland, the Scientific Committee of the InternationalHepato-Pancreato-Biliary Association (IHPBA) established a TerminologyCommittee to deal with the confusion in terminology of hepatic anatomy and liverResections. The terminology was published in the official journal of the IHPBA in 2000.The terminology shown below is based on the hepatic artery and bile duct.A terminology based on the division of the portal vein was added as an addendum.
Primary and secondary, benign and malignant liver Tumors / Liver cysts / Liver abcess and pyogenic disease / Hydatic diseaseLiver resectionsLaparoscopic Liver ResectionCryosurgeryRadiofrequency Ablation of Liver TumorsSelective Hepatic Intra-arterial ChemotherapyUnroofing and Resection for Benign Non-Parasitic Liver CystsPericystectomy for Infectious Liver CystOrthotopic Liver TransplantationPartial Cadaveric Liver Transplantation: Donor Procedure and Implantation, Right Living Donor HemihepatectomyLiving Donor Liver Transplantation: Left Hemiliver Donor Procedure and Implantation
Portal HypertensionDistal Splenorenal ShuntLow-Diameter Mesocaval ShuntInterposition Portacaval Shunt Portacaval Shunts: Side-To-Side and End-To-Side GastroesophagealDevascularization: Sugiura Type Procedures
Gallbladder and cystic duct Pear shaped sac lies to the right of the quadrate lobe in GB fossa on the visceral surface of liver Concentrates and stores bile secreted by the liver Cholecystokinin produced by intestinal mucosa during digestion, passes to GB and causes it to contract and release bile Fundus, body and neck Mucosal membrane arranged into spiral folds (valves of Heister) at GB neck and cystic duct
Gallbladder - relations Anterosuperiorly GB fossa of liver Fundus projects from inferior border of liver, located at tip of 9th costal cartilage in MCL where lateral edge of rectus abdominis meets costal margin Posteroinferiorly Neck: lesser omentum. Omental (epiploic) foramen lies immediately to the left. Body: D1 Fundus: transverse colon
Gallbladder – blood supply Arterial supply cystic artery Venous drainage directly into liver or via a cystic vein
Biliary Tree Bile is secreted by hepatocytes into bile canuliculi which drain into interlobular bile ducts. Progressively larger ducts formed. Left and right hepatic ducts emerge from porta and merge to form common hepatic duct (4cm) Joined on the right by the cystic duct from the GB to form the common bile duct (8- 10cm long, 5-6mm diameter) Runs in free edge of lesser omentum, passes posterior to D1 and head of pancreas Comes in contact with pancreatic duct on the left side of D2 Usually unite in the duodenal wall to form hepatopancreatic ampulla (of Vater) Ampulla opens into descending part of duodenum at summit of major duodenal papilla, 8-10cam from pylorus
Biliary Duct – blood supply Arterial supply Proximally: cystic artery Middle: right hepatic artery Distally: posterior superior pancreaticduodenal a. Venous drainage Proximally: drainage directly into liver Distally: posterior superior pancreaticduodenal v. Lymph drainage Cystic LN, node of omental foramen, hepatic LN’s
Biliary Tree - variants Accessory hepatic ducts may arise in the liver and join the right hepatic duct, common hepatic duct, common bile duct, cystic duct or GB Right and left hepatic ducts may fail to unite giving a double duct Cystic duct Absent Joins common hepatic duct on the left rather than the right Joins the right hepatic duct or an accessory duct Joins the common hepatic duct anywhere between the porta and the duodenum (low and high union)
Biliary Tract and GallbladderLaparoscopic Cholecystectomy, Open Cholecystectomyand CholecystostomyResection of Gallbladder Cancer, Including Surgical StagingExploration of the Common Bile Duct:The Laparoscopic ApproachBile Duct ResectionResection of the Mid Common Bile Duct Intrahepatic BiliodigestiveAnastomosis Without Indwelling StentThe Ligamentum Teres Approach and Other Approachesto the Intrahepatic Ducts for Palliative Bypass Choledochojejunostomy andCholecystojejunostomy Choledochoduodenostomy Reconstruction of BileDuct Injuries Operative Treatment of Choledochal Cysts
Pancreas Retroperitoneal organ lies transversely and slightly obliquely at L1-L2 level Transverse mesocolon attached to anterior margin Exocrine (pancreatic enzymes) and endocrine functions (glucagon and insulin) Head, neck, body and tail
Pancreas - Relations Head Lies in curvature of duodenum Anterior to IVC, aorta, right renal vessels and left renal vein Uncinate process projects posteriorly and to the left and lies posterior to superior mesenteric vessels CBD passes posteriorly in a groove or embedded within Neck Anterior to the union of splenic vein and SMV to form the portal vein Body Curves over vertebrae and great vessels Anterior to the aorta and lies between the coeliac trunk and the SMA Splenic vein passes posterior Tail lies in the splenorenal ligament Usually contacts the hilum of the spleen
A, The head of the pancreas is globular with an extension, the uncinate process, which curves behind the superiormesenteric vessels. The uncinate process may finish even before it embraces the superior mesenteric vein (a), or it maypass completely behind between the aorta and the left of the patients superior mesenteric artery (b, c). All variations arecommonly seen. Posteriorly, the head of the pancreas lies in juxtaposition to the IVC at the level of the entry of the left andright renal veins. The head of the pancreas forms a narrow neck in front of the superior mesenteric and splenic veinconfluence. The neck joins to the body of the gland, which forms a narrow tail. B, The common bile duct (CBD) passesthrough the pancreas either directly in the substance of the gland or initially with a posterior groove. C, The duct ofWirsung courses from left to right within the pancreas, curves downward approaching the CBD, and runs parallel with butseparated from it by the transampullary septum to enter the duodenum 7 to 10 cm distal to the pylorus at the papilla ofVater after traversing the sphincter of Oddi. An accessory duct (duct of Santorini) runs more proximally in the head of thepancreas and usually terminates in the duodenum at an accessory papilla. Multiple variations of the ductal system occurdepending on the extent of development of the accessory duct of Santorini, such that rarely the accessory duct can enterthe duodenum inferior to the main duct. It can be in communication with the main duct directly (i), or it can occur induplicate version known as pancreas divisum (ii). The duct of Santorini drains the body and tail of the organ, and the ductof Wirsung drains the head and the uncinate process.
Pancreatic Duct Schematic representation of the sphincter of Oddi: notch (a); biliary sphincter (b); transampullary septum (c); pancreatic sphincter (d); membranous septum of Boyden (e); common sphincter (f); smooth muscle of duodenal wall (g).
NERVE SUPPLY TO THE LIVER AND PANCREAS Note the distribution of sympathetic and parasympathetic nerves to the liver and pancreas from the celiac ganglion mainly in association with major arteries.
Stylized representation of the major nerves serving the pancreas.
Pancreas - Embryology Arises from the junction of the primitive foregut and midgut as a larger dorsal division and a smaller ventral bud Ventral bud swings posteriorly to unite with the inferior aspect of the dorsal bud trapping the superior mesenteric between divisions Ventral bud forms the uncinate process Duct of the ventral bud forms the proximal end of the main pancreatic duct; the distal end of the dorsal pancreatic duct forms the remainder.
Pancreas – blood supply Arterial supply Head: superior pancreaticoduodenal a. (from gastroduodenal artery) and inferior pancreaticoduodenal a. (from SMA) Body and tail: branches from splenic artery Venous drainage Mostly splenic v., but also portal v. and SMV
Pancreatic operation – Primary and secondary, benign and malignant pancreatic tumors / cystic lesions / pancreaticpsedeudocyst / acute and chronic pancreatitisDrainage of Pancreatic PseudocystsDenervation: Pain ManagementEnteric Ductal Drainage for Chronic PancreatitisResection for Neoplasms of the PancreasEnteric Drainage of Pancreatic Fistulas with Onlay Roux-en-YSphincteroplasty for Pancreas DivisumSphincterotomy/Sphincteroplasty for Papillary Dysfunction:Stenosing PapillitisPancreatic EnucleationTransduodenal Resection of Periampullary Villous NeoplasmsPancreas TransplantationChronic PancreatitisExploration of the Gastrinoma TriangleLaparoscopic Staging of PeriampullaryDistal Pancreatectomy