Liver Interventions Flashcards
Liver biopsy preprocedural
INR less than 1.5
aPTT less than 1.5 times
NPO 4-6 hours if iv sedation
Platelet more than 50k
Warfarin and clopidogrel 5 days before stop: restart 24 to 72 hrs
Heparin 2-6 hours before stop: restart 12 hours after
Liver biopsy approach
Subhepatic: less injury of intercostal vessels and pneumothorax
Tips indications
Indications: variceal bleed, refractory ascitis, budd chiari, hepatorenal, hepatopulmonary, hepatic hydrothorax, portal hypertensive gastropathy
Tip contraindications
Absolute: congestive heart failure, severe tricuspid regurgitation, severe pulmonary hypertension, sepsis, unrelieved biliary obstruction
Relative: polycystic liver disease, primary or mets near porta, hep v or portal v thrombosis, hep encephalopathy, hep a thrombosis
Tips technique
Right ijv to right hep v
Hepa venography
Flouroscopy to get access to port v
Portal v pressure
PTFE stent graft : covered in parenchyma till confluence of hep v and ivc, uncovered in portal v
Transtips portal venography and pressure
In variceal bleed: less than 12mmhg
In refractory ascitis: less than 8
Less than 5: can go for liver failure or hep encephalopathy
Tips Post op
Complications: transcapsular puncture causing indraperitoneal bleed
Hepatic encephalopathy: most medical management
Biliary fistula
Hep infarction
Stent migration
Follow up
Hepatofugal flow in left portal vein towards stent not towards liver
Velocity between 90 and 190 in stent
Temporal changes more than 50
Pre-op portal vein embolization
For those with inadequate FLR (future liver remnant)
Pve of the lobe to be removed, results in hypertrophy of flr
Most used in colorectal mets, intrahep cholangioCA and hcc
Percutaneous ipsilateral approach
Right hepatectomy(5 to 8) extended rt hepatectomy (4 included)
Follow up ct after 4 weeks
Chemical ablation
Tumours less than 2 cm
Coagulation and ischemic necrosis
Absolute ethanol
Have to be limited by capsule - so HCC more preferable
Not recommended for mets
RFA
Coagulation necrosis heat based
Monopolar - lead with grounding pad
Bipolar- two electrodes no gp
Cooling to prevent charring as RFA is affected by tissue impedance and heat sink effect due to adjacent blood flow
Indications: HCC with poor hepatic function or poor surgical candidates
Contraind:
Severe liver failure
Tumors close to vital structure, gb, bowel but can be separated through hydrodissection using dextrose water(artificial ascites)
Extrahep mets
Complications
Liver failure, sepsis, pv thrombosis, hemorrhage, abscess, bile duct injury
Abscess particularly common in patients with previous bile sphincterotomy or stent placement
Follow up 1 to 3 months non enhancing ablation zone with thin peripheral rim enhancement
If recurrence will show nodular enhancement
Microwave ablations
Not affected by tissue impedance (charring) or heat sink effect
But can heat up the track also
No grounding pads
Tace
Ischemic by embolization results in failure of membrane pumps so increased absorption of agents by cells and decreases washout
Doxorubicin most widely used drug
Lipiodol - oily contrast agent selectively acculumated in neovasculature and extra vascular spaces of tumors
Indications: unresectable intermediate stage HCC, multifocal or large HCC without vascular invasion or extra hepatic spread
Pre-op imaging for variants, extrahepa blood supply and port v patency
Post op 4 to 6 weeks
Tare
Yttrium 90 beta emitter
2.5 mm tissue penetration max 11 mm
Generation of oxygen free radicals of water
Even done for branch portal v thrombosis
Contra ind
Tc 99 macro aggregate albumin scan done prior to injection demonstrating hepatopulmonary shunting or gi upatke which cannot be correct by embolization
Limited hepatic reserve
Bilirubin more than 2
A prior liver radiotherapy
