95.Liver_biliary

Question 1

pringle manuever

Answer 1

20 minutes occlusion of hepatic artery and portal veinfinger in epiploic foramen(dorsal–CVC, ventral–PV, cranial–liver, caudal–hepatic artery)

Question 2

blood supply to liver

Answer 2

hepatic artery (br celiac artery): 20% blood 50% oxygenportal vein: 80% blood 50% oxygen

Question 3

where does the cystic artery arise from

Answer 3

branch of the left branch of the hepatic artery

Question 4

most proximal draining veins into the portal vein prior to liver branching (prehepatically)

Answer 4

splenic veingastroduodenal vein (most proximal–absent in cats)

Question 5

T/Fthe most cranial hepatic vein entering the caudal vena cava arises from the left hepatic lobe

Answer 5

TRUEleft branches are the most cranial, then central branches and then the most caudal are right branches located within the parenchyma

Question 6

lobes of the liver

Answer 6

6 lobesleft medialleft lateralright medialright lateralcaudate —caudate and papillary processesquadrate

Question 7

biliary flow

Answer 7

canaliculiinterlobular ductslobar ductshepatic ducts (2-8)CBD*at the point where the first hepatic duct meets the cystic duct= CBDenter at major duodenal papilla, sphincter of Oddi (adjacent to but not conjoined to pancreatic duct—conjoined in cats)80% cats do NOT have minor duodenal papilla for accessory pancreatic duct

Question 8

functions of liver (6)

Answer 8

dysfxn occurs with 70-80% loss of liver–protein synthesis (20% of TP)–CHO metabolism (glucose homeostasis)–Lipid metabolism (makes cholesterol, stores fat in the form of TG from free FA)–immune system:reticuloendothelial phagocytic function of harmful substances, Kuppfer cells (macros)–all coag factors including vit K dependent factors 2, 7, 9, 10 (liver does not make VIII, vWF) and vit K, TPO, fibrinogen–bile production: made up of bile acids, bilirubin (80% from Hb), cholesterol, phospholipids, water, bicarb, ions

Question 9

physiology of Hb breakdown

Answer 9

reticuloendothelial function of liver (extravascular) breakdown of Hb–bilirubin is bound to alb and taken to liver–conjugated in liver to glucuronic acid and secreted into bile –combine with bile acids (taurine–cats, taurine or glycine–dogs WITH cholesterol)–conjugated bili and bile acids travel to GB for storage–SI stimulated release of CCK causes GB to contract and sphincter of Oddi to relax–bile salts emulsify fats (miscelle formation) and bind endotoxin to prevent their absorption–bilirubin is degraded to urobilinogen by bacT–urobilinogen is converted to urobilin or stercobilin (brwn color feces)–90% passage in feces; 10% re-circulation within portal system

Question 10

regenerative capacity of liver

Answer 10

incredible regenerative capacity–begins within hours and peaks at 3 daystolerates removal of 65-70%BUT NOT >80%compensatory hypertrophy and hyperplasiahepatic arterial buffer response–change in portal pressure with massive resection will increase hepatic arterial perfusion (portal vein embolization can increase liver volumes 25-30%)cytokines also enhance regeneration (insulin, estrogen, growth factors, PG, etc)

Question 11

factors that impede liver regeneration

Answer 11

diabetes mellitus (decr insulin which is a major hepatotrophic hormone)male genderbile obstruction agemalnutrition

Question 12

common location of trauma biliary tract rupture

Answer 12

–CBD (body)–hepatic ductsRARELY from GB itself

Question 13

most common causes of EHBO in dogs

Answer 13

–GB mucocele–pancreatitis–neoplasia–cholangitis–cholelithiasis(can also have FB or mass in duodenum)

Question 14

most common causes of EHBO in cats

Answer 14

–complex inflammatory dz (pancreatitis,cholangiohepatitis, cholecystitis with or without stones)–neoplasia(less common: parasites–flukes, diaphragmatic hernia)

Question 15

after acute ligation of CBD in dogs, how long does it take for dilation to occur

Answer 15

dilation of CBD occurs within 24-48 hrs (along with an increase in serum bilirubin)dilation of lobar/interlobular ducts takes 4-6 days

Question 16

pathophysiologic consequences of EHBO

Answer 16

absence of bile salts in SI leads to increase bacT overgrowth and endotoxin absorption, impaired clearance of endotoxin through RE system of liver so systemic endotoxemia ensues–hypotension–coagulopathy (DIC)–GI bleeding (endotoxemia related gastric ischemia and incr acid production)–delayed wound healing (decr fibroplasia/angiogenesis)–decreased myocardial contractility –acute renal failure (endotoxemic = renal vasoconstrictor, acute tubular necrosis)

Question 17

bile peritonitis causes in dogs

Answer 17

–trauma–necrotizing cholecystitis–ruptured GB mucoceleRARE in cats –think traumacan also have a proximal duodenal perf with bile peritonitis if near major duodenal papillabilirubin in ab fluid 2x > peripheral blood bilirubin

Question 18

pathophysiology bile peritonitis

Answer 18

bile salts are hyperosmolar in ab cavity (fluid shifts)inflammation, necrosis, hemolysis occurnormally sterile but can have bacT from ascending GI, colonization of liver bacT, bacT translocation, or from direct inoculation with penetrating injury septic biliary effusions greatly worsen px

Question 19

T/Fwhen bile salts are not present in SI to bind endotoxin, systemic endotoxemia may develop

Answer 19

TRUEin the GI, bile salts emulsify fats (miscelle formation) and bind endotoxin to prevent their absorptionwhen they are not available INCR bacT and INCR endotoxin

Question 20

hepatobiliary imaging

Answer 20

–survey rads (not SN/SP: mineralization (may be incidental, gas, liver size, mass effect, stones)–ab US (FNA, biopsy, centesis, color flow doppler, contrast enhanced harmonic US w gas microbubbles)–hepatobiliary scintigraphy (quantifies liver function; technetium iminodiacetic acid accumulate within biliary tract; if not seen in SI in 3 hours== EHBO; limitation of mechanical vs functional obstruction and location)–CT/MRI–Endoscopic retrograde cholangiopancreatography (ERCP)–contrast, stone removal or stent placement

Question 21

cholelithiasis composition in dogs and cats

Answer 21

50% opaque dogs (calcium bilirubinate)80% opaque cats (calcium carbonate)usually found near major duodenal papilla–can do sphincterotomycholecystectomy preferred after retrograde flushing stone back into GB and ensuring patency (recurrence is not reported if GB removed)other options (especially if CBD is not patent): cholodochotomy (dehisce! and stricture) or cholecystoenterostomy (recurrence seen)

Question 22

normal CBD diameter on ab US

Answer 22

CBD normal diameter dogs and cats 3-4 mm

Question 23

typical US appearance of GB mucocele

Answer 23

immobile stellate or finely striated GBkiwi fruit

Question 24

method to monitor EHBO with serial ab US

Answer 24

can give synthetic CCK (sincalide) IVnormally, GB should empty 40% within 1 hrEHBO if empty <20%

Question 25

coagulation testing of liver patients prior to surgery

Answer 25

CBC (blood smear, platelets), Chem, UAcoag panel (PT, aPTT, ACT)PIVKA (most SN)blood type cross match57% dogs with confirmed liver disease will have at least one abN coagulation parameterMayhew it al 2013 TEG for EHBO suggest HYPERCOAGincreased tendency for hemorrhage in dogs with natural liver disease has not been demonstrated

Question 26

surgical liver cultures

Answer 26

sx and lap liver cultures had sign more positive results than percutaneous needle biopsyintraop biliary culture was significantly more likely to have positive culture than liver culture (30 vs 7%)Ab recommendations1. fluoroquin, penicillin, metro2. fluoroquin, amoxi-clav3. fluoroquin, clindamycin

Question 27

methods to control extensive hemorrhage during liver surgery

Answer 27

maintenance of CVP < 5 cm H20 is essential for minimizing blood loss1. inflow occlusion–Pringle Manuever (hepatic artery and portal vein 20 min occlusion)–dogs have less collateral circulation than humans2. total hepatic vascular exclusion–simultaneous occlusion of cranial and caudal VC–with concurrent inflow (hepatic artery and portal vein) occlusion–dramatically reduces cardiac preload; brief occlusion only3. hepatic artery ligation–supplies only 20% to liver but generally it is the major (95%) supply to liver tumor–give ANTIBIOTICS–attempt to ligate lobar arteries if possible–consider cholecystectomy–ensure portal vein flow

Question 28

overall agreement with FNA and histopath of liver lesions in dogs and cats

Answer 28

dogs 30%cats 50%

Question 29

liver biopsy

Answer 29

punch biopsies bleed the mostligature and harmonic scalpel may bleed the least(other options: lap biopsy forceps, lap endoloop or extracorporeal loop ligature, biopsy needle/Trucut, vessel sealing device)obtain enough for histopathology, culture, and toxicology

Question 30

methods of exposure for partial or complete liver resection

Answer 30

1. midline celiotomy—may extend into caudal thorax/median sternotomy2. puncture the diaphragm3. lap sponges btwn diaphragm and liver lobes to retract caudally4. cut triangular ligaments5. paracostal incision

Question 31

contributions of liver volume from each lobe

Answer 31

tolerate 65-70% resectionright lateral and caudate make up 28%right medial and quadrate make up 28%left lateral and left medial make up 44%

Question 32

methods of regional tumor control for diffuse or metastatic or not amenable to surgery tumors

Answer 32

percutaneous ablation techniques1. radiofrequency ablation2. microwave ablation3. laser thermal ablation4. cryoablation5. ethanol ablationintravascular tumor embolization/chemoembolizationintra-arterial (lesional) chemotherapy

Question 33

when is clinical icterus present

Answer 33

with serum bilirubin >1.5-2.0 mg/dL

Question 34

preparation of hepatic patient for liver surgery

Answer 34

–fluids–vitamin K 1-2 mg/kg SQ q 12 hr–FFP, whole blood, pRBC if needed–Ab perioperatively–GI protectants +/-(based on prep PE, imaging, and bloodwork/coag panel/blood typing)

Question 35

surgical decision making for extra hepatic biliary tree

Answer 35

–check patency (normograde or retrograde* choledochal flushing)–if NOT patent: reroute: cholecystoduodenostomy* (preferred), cholecystojejunostomy (suture or EndoGIA)–if PATENT and potential reversible disease (pancreatitis, cholangitis, +/- trauma to CBD) or palliation for malignancy: stent or cholecystotomy tube–if PATENT but NOT reversible disease (stones, neoplasia, GB mucocele, trauma to GB, necrosis of GB): cholecystectomy (open, laparoscopic)

Question 36

T/Fdiversion of bile from the duodenum (as with cholecystojejunostomy) can lead to duodenal ulceration in dogs

Answer 36

TRUEwithout bile in duodenum, duodenal ulcers occurnormally when bile is present in SI, gastric acid secretion is inhibitedif bile is gone and inhibitory feedback is loss, gastric over secretion may occur leading to ulcer formation in the duodenum

Question 37

stoma size created during a cholecystoenterostomy

Answer 37

antimesenteric SI incision with longitudinal incision in GBcreate stoma as long as possiblesmall stomas < 2.5 cm may predispose to obstruction and stricture formationeach side is sutured with simple continuous single layer+/- apical suture at each end to relieve tension3-0- 4-0 monofilament absorbable(double layer may invert and decrease lumen–stricture)

Question 38

possible complications following rerouting cholecystostomy

Answer 38

–hemorrhage–gastric/duodenal ulceration–stricture–re-obstruction–dehiscence/bile peritonitis–ascending cholangiohepatitis

Question 39

most common indication for surgery management of EHBO in dogs

Answer 39

GB mucocele–cystic mucosal hyperplasia and hypersecretionshetland sheepdogs (GB disease) predispositionhypoT (14% vs 5%)hyperadrenocorticism (risk 29x GB mucocele–21% vs 2%)cholecystectomy (check patency first!)

Question 40

ab US sensitivity for detecting GB rupture

Answer 40

86%

Question 41

medical mgmt for GB mucocele

Answer 41

1. ursodial: choleretic, immunomodulatory2. S-adenosyl-L-methionine (SAM-e): anti-inflammatory, antioxidant3. famotidine: H2 receptor antagonist4. vitamin E: antioxidant, anti-inflammatory 5. Silymarin (milk thistle): anti-oxidant, choleretic, antifibrotic/anti-inflammatory

Question 42

complications following cholecystectomy for GB mucocele removal

Answer 42

1. leakage/peritonitis2. pancreatitis3. reobstruction if congealed bile in CBD

Question 43

prognosis following cholecystectomy for GB mucocele

Answer 43

Worley et al JAVMA 2004 (22 dogs)70% survivalPike et al JAVMA 2004 (30 dogs)22% mortality (80% survival)GB rupture was NOT associated with increased mortality

Question 44

what constitutes “triaditis” in cats

Answer 44

–IBD–pancreatitis–cholecystitis

Question 45

4 types of primary hepatobiliary tumors

Answer 45

1. hepatocellular adenomas and adenocarcinomas (massive, nodular, diffuse)2. cholangiocellular adenomas and adenocarcinomas3. neuroendocrine carcinomas (aggressive, diffuse, poor px)4. mesenchymal (HSA, leiomyosarcoma, OSA, FSA): poor px(mets to liver are more common than primary liver tumor #1 hematopoetic/lymphoid #2 epithelial/mesenchymal)

Question 46

paraneoplastic condition related to variety of hepatic neoplasms

Answer 46

hypoglycemia

Question 47

T/Fcorrelation with ultrasound live appearance and tissue histopathology is poor

Answer 47

TRUEways to enhance correlation:contrast enhanced harmonic US (microgas bubble)MRI

Question 48

hemorrhage/hematoma formation complication rate following percutaneous needle core liver biopsy

Answer 48

<6%

Question 49

T/Flaparoscopic liver biopsy contains fewer portal triads and hepatic lobules than traditional open technique

Answer 49

true

Question 50

most common hepatocellular liver tumor in dogs

Answer 50

hepatocellular carcinoma 70%; 30% adenomas)–massive (60%)–usually L sided; favorable px with resection; MST 1400d–nodular (30%)–higher met rate–diffuse (10%)–higher met rate

Question 51

prognosis with liver resection and massive hepatocellular carcinoma according to Liptak 2004 JAVMA 48 cases

Answer 51

1400 days MSTperiop mortality 5%poor px associated with R sided tumors NOT with incomplete resection (10%)

Question 52

T/Fin cats, hepatocellular adenomas is more comma than hepatocellular carcinomas

Answer 52

truein cats, bile duct tumors are the most common primary hepatic neoplasm–benign cyst adenomas (good px) are TWICE as common as bile duct carcinomas (100% mortality)