Chapter 164 - Portal hypertension Flashcards
Definition of portal hypertension
Abnormal increase in pressure that carry blood from visceral to liver 10 mmHg above systemic venous pressure
Ohm’s law
Change in pressure (delta P) = flow (Q) x resistance (R)
Normal portal pressure
5-10 mmHg
Pathogenesis of liver cirrhosis
decrease vasodilator, increase vasoconstriction, increase fibrosis –> increase portal pressure splanchnic vasodilation –> increase HR and CO –> arterial hypotension –> high pressure baroreceptor and sympathetic nervous system –> vasoconstrictor –> hypodynamic system –> shunt blood to low resistance = esophageal varices
Portal hypertension classes
1) extrahepatic 2) intrahepatic 3) post hepatic
Extrahepatic pre-sinusoidal obstruction causes
thrombosis of portal vein children: infection adult: cirrhosis, iatrogenic, cancer, hypercoagulable, inflammatory Risk 0.6-22%
Intrahepatic presinusoidal obstruction causes
Fibrosis and compression of portal vein deposits of stuff causes inflammation in portal vein 1) hepatic fibrosis 2) chronic arsenic exposure 3) sarcoidosis 4) wilson disease 5) hepatoportal sclerosis 6) primary biliary cirrhosis 7) Schistosomiasis (most common in 3rd world) 8) myeloproliferative disorders
Intrahepatic sinusoidal and postsinusoidal causes and mechanism
Most common in western world Cirrhotic bands and regeneration nodules disrupt normal architecture Cause AV shunt and collateral with 33% bypassing hepatocytes Increase CO, decrease systemic resistance, increase hepatic wedge pressure, increase portal pressure Sinusoidal: 1) EtOH 2) viral 3) toxic hepatitis Post-sinusoid 1) EtOH 2) postnecrotic cirrhosis 3) hemochromatosis
Extrahepatic postsinusoidal obstruction causes
Hepatic vein thrombosis 1) malignancy 2) trauma 3) pregnancy 4) oral contraceptives 5) Budd-Chiari associated myeloproliferative disease with hypercoagulable state Cardiac disease
AVF in portal hypertension causes
Increase in portal circulation causes fibrosis 1) iatrogenic 2) trauma 3) splenic aneurysm 4) sarcoidosis 5) Gauche disease 6) myeloid metaplasia
Clinical presentation of portal hypertension
1) Ascites 2) spider angioma 3) palmer erythema 4) Gynecomastia 5) enlarged abdominal wall collaterals (caput medusae) 6) muscle wasting 7) variceal bleed 8) fatigue 9) asterixis 10) encephalopathy
Pathogenesis of variceal formation in portal hypertension
1) Dysfunction of preexisting embryonic connection 2) neoangiogenesis Collaterals form at 10-12 mmHg above systemic pressure
Varices pathway in portal hypertension
Portal vein –> left gastric vein –> esophageal varices Splenic vein –> short gastric vein –> esophageal and gastric varices Both into venous plexus of lamina propia and submucosa of esophagus and stomach –> azygos venous system
Esophageal varices zones
1) Gastric 2) Palisade 3) Transitional (2 cm above GEJ to 2 cm above that) 4) Truncal
Gastric varices types
1) extend above GEJ as esophageal 2) isolated to stomach common in fundus
Caput medusae pathogenesis
Left portal vein to periumbilical vein in falciform ligament
Rate of varices in cirrhosis at diagnosis
50%
Rate of varices in cirrhosis with long term f/u
90%
Defn of small or large varices and respective bleed/rupture rate
5 mm cutoff small 7%/2 yr large 30%/2yr
Mortality associated with variceal bleed
35% 60% if rebleed in 1 yr 20% every subsequent bleed
Pathogenesis of variceal bleeding
Explosion hypothesis Hydrostatic pressure increase > 10 mmHg, variceal dilation, decrease wall thickness –> rupture (LaPlace Law)
Critical hepatic venous gradient
12 mmHg
Ascites rate in portal hypertension
80%
Pathology of ascites in portal hypertension
Starling forces with low oncotic pressure and high hydrostatic pressure lymphatic system overwhelmed
Risk of ascites
Spontaneous bacterial peritonitis 30% need hospitalization due to SBP
Type of bacteria in spontaneous bacterial peritonitis
Gram negative aerobes most (GI source) 1/3 Gram +
Encephalopathy definition
Any neuropsychiatric dysfunction caused by liver disease ranging from subclinical to coma/death
Pathology of encephalopathy
Hepatocyte malfunction –> portosystemic shunt –> ammonia and glutamine –> brain astrocyte mitochondrial dysfunction –> altered cerebral function, edema, herniation
Wes Haven Criteria is for
Hepatic encephalopathy Grade 1 + 2 = cognition, sleep patter alteration, mood, disorientation, asterixis, apathy, drowsy Grade 3 + 4 = coma, somnolence
Rate of encephalopathy in decompensated liver failure
30-40%
Hepatorenal syndrome defn
Renal dysfunction in presence of cirrhosis and ascites Diagnosis of exclusion
Symptom of hepatorenal syndrome
1) oliguria 2) hyponatremia 3) low urine sodium
Hepatorenal syndrome types
rapid (within 2 weeks of hepatic) vs chronic rapid poor prognosis 90% inhospital mortality
Hepatopulmonary/portopulmonary syndrome defn
Combination of portal hypretension, pulmonary hypertension, pulmonary vasodilate/shunt, impaired oxygenation
Symptoms of hepatopulmonary syndrome
1) clubbing 2) dyspnea 3) deoxygenation
Laboratory workup for portal hypertension
1) arterial gas 2) lactate 3) CBC 4) PTT/INR 5) fibrinogen 6) factor V 7) AST/ALT/ALP 8) bili 9) LDH 10) amylase/lipase 11) magnesium, PO4 12) CK 13) metabolic panels
Other specific tests for portal hypertension
1) HIV 2) Hepatitis 3) ceruloplasmin 4) serum copper 5) ANA 6) tox screen 7) testosterone (low in 90% of men with cirrhosis; associated with mortality)
When to GI scope in portal hypertension and what can be found
All with varices should get scope repeat 3-6 months after bleed Dx: gastropathy, gastritis, ulcers, mucosal laceration
Benefit of liver biopsy in portal hypertension and what can be found
Etiology and acuity information Cirrhosis: 1) rounding of edges 2) nodularity 3) loss of terminal hepatic venules 4) increase vascular channels in scars and fibrosis 5) hepatocyte regeneration
Liver biopsy: finding of plastma cell in portal/septal interface
Hepatitis B
Liver biopsy: Mallory-Denk bodies
Eosinophilic cytoplasmic inclusion bodies that hover hepatocyte nucleus 1) EtOH 2) Wilson 3) drug induced 4) primary biliary cirrhosis
Liver biopsy: pipestem fibrosis
chronic schistosomiasis (calcified egg and granuloma) if live will see live egg with eosinophils
Success in endoscopic sclerotherapy
Cyanoacrylate 93% success; 7% rebleed
Side effect of endoscopic sclerotherapy
Pulmonary and cerebral embolization
Sclerotherapy vs banding in varices
similar results
Acute hemorrhage spontaneous resolution rate and why
40-50% 1) hypovolemia 2) splanchnic vasoconstriction
Treatment for acute variceal bleed
1) vasopresin (60-80% success; decrease mortality, SE decrease CO) 2) somatostatin 3) octreotide 4) balloon tamponade 5) EVBL 6) sclerotherapy 7) BRTO/BATO 8) TIPS
Benefit of octreotide over somatostatin in variceal bleed
half life, octreotide 100 min vs somatostatin 2 min
Sengstaken-Blakemore balloon
AKA Linton-Nachlas 2 balloons: 1 for esophageal and 1 for gastric port to sunction gastric content Minnesota balloon has 2nd suction for esophagus
Risk of balloons in esophageal varices
1) aspiration pneumonia 2) airway obtsruction 3) tube migration 4) esophageal ulceration 5) rupture
Balloon-occluded retrograde transvenous obliteration (BRTO) goal and steps
Goal: occlude portosystemic collaterals between stomach and renal vein 1) treat esophageal varices first 2) evaluate portal vein patency 3) sclerosing agent injected with balloon in place 4) balloon up for 4-24 hours 5) can increase portal HTN and worsen it Success rate 91-100%
Balloon-occluded antegrade transvenous obliteration (BATO) goals and steps
Goal: occlude collaterals from portal system from gastric veins in antegrade fashion 3 ways to access: 1) perc transhepatic 2) existing TIPS 3) trans-ileocolic vein (for mesenteric varices only) increase BRTO alone success to 98-100%
Duplex scanning in portal hypertension use
1) portal vein patency 2) direction of flow via portal vein 3) surveillance post treatment
CTA in portal hypertension use
1) determine patency of portal vein 2) chronicity 3) pathologic features
Percutaneous angiogram in portal hypertension uses
Transhepatic portal venography 1) portal tributaries 2) portal hepatic wedge pressure Severe cirrhosis: 1) dense collaterals 2) dilation of hepatic artery 3) reversal of flow in portal vein
Prevent bleeding in primary prevention of portal hypertension
1) beta blockade 2) endosopic variceal band ligation 3) endoscopic sclerotherapy
Beta blockade in portal hypertension
Non-selective Propranol or carvedilol Reduce CO –> decrease systemic pressure –> decrease portal pressure
Endoscopic variceal band ligation in portal hypertension risks
Perforation pain bleed
Transjugular intrahepatic portosystemic shunt (TIPS) uses and success rate and steps
For refractory variceal bleed and ascites Success 97%, complication < 3% 1) IJ access 2) select right hepatic vein (middle and left less optimal) 3) balloon catheter to wedge venogram 4) direct guide cath to portal vein 5) trocar stylet pass parenchyma towards portal vein 6) 10 Fr guide cath to portal system 8) deploy covered stent 9) check pressure gradient to less than 12 mmHg
TIPS vs BRTO results
no direct comparisons available; TIPS lower recurrence
Rebleeding in portal hypertension most common when
first 5 days; otherwise 80% in 1 year without prophylaxis
Secondary prevention in portal hypertension bleed
1) beta blocker 2) EBVL TIPS decrease bleed but increase risk of encephalopathy
Ascites treatment
1) Spironolactone 100 mg - 400 mg for weight loss 2) furosemide 40 - 160 mg; prevent hyperkalemia
Encephalopathy treatment
1) correct inciting condition (bleed, infection, electrolyte imbalance, restric ammonia) 2) lactulose (prevent ammonia absorption and increase fecal nitrogen excretion 3) neomycin (SE: nephrotoxic and ototoxic)
Hepatic and portal recanalizations steps
1) IJ or fem approach to get hepatic vein 2) if fail then transhepatic percutaneous then snare wire Vs TIPS: less complication, less encephalopathy For liver transplant candidacy may embolize varices to maintain portal patency
Portosystemic bypass bleed recurrence
< 3% no role as prophylaxis because risk of encephalopathy
Selective vs non-selective shunts in portal hypertension
Selective: preseve blood flow to portal vein while decompressing esophageal varices i.e. distal splenorenal shunt Non-selective shunt = drain all portal blood to caval system 1) portocaval shunt 2) mesocaval shunt selective has less liver failure and encephalopathy
Portocaval shunt steps
1) midline or RUQ subcostal incision 2) mobilize duodenum 3) isolate IVC 4) isolate PV from hepatic artery and bile duct 5) divide portal vein if doing end-to-side; ligate hepatic side of it and sew the other to IVC 5b) portal to IVC proximity and sew together or use PTFE if doing side-to-side Portal pressure should decrease by > 50%
Mesocaval shunt used for
1) hemorrhage 2) massive ascites 3) obliterated portal vein 4) obesity 5) Budd-Chiari syndrome
Steps in mesocaval shunt
1) midline laparotomy 2) colon rotate superiorly 3) SB rotate inferiorly 4) expose root of SB mesentary 5) open root of transverse mesocolon to expose SMV 6) identify IVC 7) PTFE 18-20 mm bypass SMV to IVC Should decrease portal pressure by > 50% and palpate thrill in graft
Ddistal spleno-renal shunt steps
1) bilateral subcostal incision 2) open lesser sac 3) identify splenic vein 4) right gastroepiploic vein divided but preserve short gastric veins 5) rotate pancreas anteriorly to expose splenic vein 6) ligate connection to pancreas 7) divide ligament of treitz and rotate 4th duodenum inferiorly 8) identify renal vein 9) divide splenic vein 10) divide connection to SMV 11) end to side renal vein 12) divide collateral betwen portal-azygos and portal-mesenteric 13) divide left gastric vein and umbilical vein and falciform ligament should crease splenic pressure by 60-70%
Benefit of surgery in portal hypertension
1) better patency 2) better prevention of recurrent bleed 3) more likely to survive after transplant
Causes of portal hypertension
