Update onImaging in Liver Transplantation

Dr.Manoj.K.S.MD DNB RD

KIMS

Introduction

• Liver transplantation, first introduced 40 years back, is the recognized treatment of choice for patients suffering from end-stage liver disease, including documented fulminant hepatic failure, decompensatedcirrhosis, or hepatocellular carcinoma within defined criteria.

• Approximately 800-1000 liver transplant surgeries are performed in India annually

• The number of liver transplantations performed in the United States each year exceeds 6000; however, there are more than 15,000 patients on the waiting list.

• UNOS National Data Report. http://www.unos.org 2011

History

• The first human liver transplants were performed in 1963 by a surgical team led by Dr. Thomas Starzl of Denver,at University of Colorado Medical School.

• Dr.Christian Barnard performed the first Heart transplant on December 3, 1967 in Cape Town, South Africa.

• https://www.kidney.org/transplantation/transaction/Milestones-Organ-Transplantation

INDICATIONS

• Complications of cirrhosis

• Fulminant hepatic failure

• Encephalopathy

• Ascites

• Hepatocellular carcinoma

• Refractory variceal hemorrhage

• Chronic gastrointestinal blood loss due to portal hypertensive gastropathy

INDICATIONS• Hepatitis

• Autoimmune hepatitis

• Chronic hepatitis B

• Chronic hepatitis C

• Chronic cholestatic diseases

• Primary biliary cirrhosis

• Primary sclerosing cholangitis

• Metabolic liver diseases

• Hemochromatosis

• Wilson disease

Contraindications

• Absolute contraindications• Active extrahepatic malignancy• Diffuse hepatic tumor invasion• Thrombosis of the entire portal and SMV system• Active or uncontrolled systemic infection• Active substance or alcohol abuse• Severe cardiopulmonary disease or other comorbid conditions• Lack of social support• Noncompliance• Relative contraindications• Age Cholangiocarcinoma Portal vein thrombosis Chronic

or refractory infection HIV infection Previous malignancyActive psychiatric disorder Poor social support

Three main types of liver transplantation: cadaveric (DDLT), LDLT, and split-liver grafting

• The Model for End-Stage Liver Disease (MELD) is a scoring system used to assess the severity of CLD

• 3-month mortality rate among those with a MELD score of 40 is 100%. For patients with a score of 30–39, mortality within 3 months is 83%; for 20–29, 76%; for 0–19, 27%; and for patients with a score of less than 10, 4%.

The imaging requirements for a Liver Transplantation Unit can be considered under these broad Categories .

• 1.DONOR EVALUATION

• 2.RECIPIENT EVALUATION

• 3.INTRA OPERATIVE IMAGING

• 4. POST TRANSPLANT IMAGING

• 5. FOLLOW UP

DDLT -Donor evaluation

• Pre-operative USG /Doppler

• Intra operative biopsy

DONOR EVALUATION

• CHEST X-RAY

• ULTRASOUND ABDOMEN

• PORTAL/HEPATIC VEIN DOPPLER

Recipient EvaluationRole of Imaging

• Candidate selection

• Search for intra and extrahepatic malignancy

• Surgical planning

– HCC Staging

– Assessment of vessel patency: angioinvasion

– Quantification of diseased liver volume

– Vascular anatomy

– Identification of cirrhosis and sequelae of PHTT

RECIPIENT EVALUATION

• TRIPHASIC CT LIVER & ABDOMEN/PELVIS

• CT /HRCT CHEST

• USG/DOPPLER LIVER

• MRI LIVER & MRCP

• X-RAY CHEST

RECIPIENT EVALUATION• PET SCAN• RADIONUCLIDE SCAN

• MRI Brain • MR Angiography cerebral arteries• Carotid Doppler• Renal artery Doppler

• LIVER BIOPSY

• Cardiac Imaging –Echo, DSE, Contrast Echo,CAG• CT Pulmonary Angio/Lung Perfusion scan

PET SCAN

Recipient Evaluation

Milan & UCSF Criteria

• Milan criteria :

Defined as 1 tumor ≤5 cm; or ≤3 tumors with each tumor ≤3 cm.

• UCSF criteria

Defined as 1 tumor ≤6.5 cm or ≤3 tumors with the largest tumor diameter ≤4.5 cm and total tumor diameter ≤8 cm

Interventional Radiology

• RFA

• TACE

• TARE

• PTBD

• PVE

• TIPS

• Portal vein thrombectomy

• Hepatic venous pressure gradient (HVPG)

INTRA OPERATIVE IMAGING

• Intraoperative Doppler

• Intraoperative Cholangiography

Intraoperative Cholangiogram

Post Transplant Imaging

• Post- operative Doppler

• PORTABLE X-RAY in ICU

• HIDA Scan for post transplant leak assessment

• TRIPLE PHASE CT LIVER (optional before discharge)

Post- operative USG/DopplerStructure Comment

Liver parenchyma Evaluate parenchymal echogenicity, texture and presence of focal lesions

Perihepatic spaces Evaluate for acites, hemorrhage, fluid collections

Biliary system Evaluate for ductal dilatation and intraluminal filling defects

Vasculature >Evaluate hepatic artery, portal vein, hepatic veins and IVC for patency>Evaluate arterial and venous waveforms and measure arterial resistive indices>Evaluate anastomoses for focal color aliasing and elevated velocities

Post Tx Doppler

Hepatic veins -Normal

a wave (atrial systole)

S wave Ven systole

D wave Ven diastole

Post Tx Doppler

Post Transplant Doppler –Artery

In a post-transplant patient, the normal hepatic arterial RI ranges from 0.55 to 0.80

Post Tx Doppler

DONOR EVALUATION

• LIVER STEATOSIS ASSESSMENT

• CT ANGIO LIVER

• CT VOLUMETRY

DONOR EVALUATION

• MRCP

• MRI Liver

• LIVER FIBROSIS assessment with Ultrasound or MR elastography

DONOR EVALUATION

• Mammography

• USG pelvis

• USG Thyroid

• Doppler lower limb arteries/veins

CT Imaging

MR Imaging

LIVER FAT ASSESSMENT

• Liver Attenuation Index (LAI).

• The LAI is the difference between mean hepatic attenuation and mean splenic attenuation (i.e. average density of liver − average density of spleen on non-contrast scan).

• Liver attenuation is calculated by placing the circular region of interest (ROI) of at least 1 cm² area at multiple places in the liver, covering all the hepatic segments

Liver Attenuation Index

• Average attenuation of liver parenchyma on non-contrast CT images varies between 50 and 65 HU and is generally 8-10 HU greater than that of spleen.

• Limanond et al. found in their study that LAI > 5 HU correctly predicted the absence of significant macrovesicular steatosis.

• LAI values of -10 to 5 HU were suggestive of mild to moderate steatosis (6-30%), while LAI values of less than -10 HU were suggestive of moderate to severe hepatic steatosis (i.e. ≥30% fat) with a specificity of 100%.

• Limanond P, Raman SS, Lassman C, Sayre J, Ghobrial RM, Busuttil RW, et al. Macrovesicular hepatic steatosis in living related liver donors: Correlation between CT and histologic findings. Radiology 2004;230:276-80

MR Fat Quantification

• In Phase-Opposed phase

• 3 Point Dixon

• MR Spectroscopy –SVS with PRESS

LDLT

• The most common LDLT technique in adults is right hemihepatectomy, whereby segments V-VIII are harvested, leaving the middle hepatic vein (MHV) with the donor. Right hemi-liver along with its artery, portal vein, bile duct, and the draining hepatic veins is implanted into the recipient.

LDLT

• In pediatric liver transplants, left lateral sectionectomy is the standard method, whereby segments II and III are harvested

• In certain situations of adult LDLT, where either the remnant liver volume in donor is inadequate or there is complex portal venous or biliaryanatomy, a right posterior sectionectomy can also be performed by harvesting only segments VI and VII with their posterior sectional hepatic artery, portal vein, bile duct, and right hepatic vein (RHV)

Arterial reconstruction

•

The conventional hepatic arterial “fish-mouth” anastomosis is an end-to-end anastomosis reconstructed between the donor and recipient arterial anastomoticsites, usually between the splenic artery and common hepatic artery

For cadaveric donors, the donor hepatic artery is harvested at the level of the celiac axis with a patch of the aorta. The aortic patch is then anastomosed to the recipient hepatic artery near the gastroduodenal artery take-off. For living donors, the arterial anastomosis is to the right, left or proper hepatic artery

PV/IVC/BILIARY

• A portal vein anastomosis is usually an end-to-end anastomosis between the two portal veins.

• The piggyback technique is the standard technique IVC .An end-to-side anastomosis is made between the donor IVC and the common stump of recipient hepatic vein

• Biliary anastomosis is an end-to-end anastomosis between the donor common bile duct and the recipient common hepatic duct after a cholecystectomy

SEGMENTAL ANATOMY

ARTERIAL ANATOMY

PORTAL VEIN -3D MIP

Hepatic Veins -3D MIP

Total volume

RIGHT & LEFT LOBE VOLUME

Partial volumes

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

DONOR MRCP

FOLLOW UP /COMPLICATIONS

• DOPPLER & ULTRASOUND SCAN

• MRI & MRCP

• CT ABDOMEN /CHEST

• CT ANGIOGRAPHY

• MR ANGIOGRAPHY

• DSA

• SCINTIGRAPHY -HIDA

• ERCP

• LIVER BIOPSY

• CONTRAST ULTRASOUND

• INTERVENTIONAL RADIOLOGY

• PET-CT/ BONE SCAN

IR in LT Complications

• Vascular

• Biliary

• General

• Vascular – Hepatic Artery Stenosis/Thrombosis (HAS/HAT), Portal/Hepatic vein,IVC stenosisi

• Biliary leak, strictures

• Drainage of collections, Pleural effusion etc

Combined Liver-Kidney Transplantation

First Pediatric LT at KIMS

Second Pediatric CLKT at KIMS

Special Thanks to

• Dr. B.Venugopal• Dr.Madhavan Unni• Dr.Shabeer Ali• Dr.L.Jayasree• Dr.R C Sreekumar• Dr.Manoj Pillai• Dr.Suresh Babu• Dr.Manish Yadav• Dr.Malini• Dr.Shiraz• Mr Judson• Mr Siraj• Liver Transplant Team KIMS • IMA Trivandrum

THANKS TOTCCI

IMA,APS ,SCOGDEPT OF

RADIOLOGY, HPB&LT,KIMS