Dr/Ahmed A Bahnassy

Consultant RadiologistPSMMC

Liver transplantation is the most effective treatment for various end-stage liver diseases. Living donor liver

transplantation (LDLT) was first developed in Asia due to the severe lack of cadaveric graft in this region.

Evaluation of recipient Pre-transplant imaging plays an important

role in identifying contraindications to transplantation, anatomic abnormalities and variants that may alter the surgical

approach.

Liver parenchyma

Ultrasound may show changes of cirrhosis with nodular contours, parenchymal inhomogeneity, right lobe atrophy and hypertrophy of lateral segment and caudate lobe .

Doppler US signs of PHT in cirrhosis

• P-S collaterals Highly sensitive & specific• Portal vein Dilated PV

Decreased mean velocity (< 15 cm/sec)To-and-fro flow /Hepatofugal flowIncreased pulsatility (VPI)Arterio-portal fistula

• Hepatic vein Compression (Pseudo-portal flow)• Hepatic artery Enlargement & tortuosity

Increased RI & PI

Harkanyi Z. Ultrasound Clin 2006 ; 1 : 443 – 455.

Common spontaneous porto-systemic collateralsMore than 20 P-S collaterals described

Patnquin1 H et al. Am J Roentgenol 1987 ; 149 : 71 – 76.

Most common: LGV – PUV – Spleno-renal – Gastro-renal

P-S collaterals / Coronary veinMost prevalent (80-90%) – Most clinically important

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Sagittal view slightly superior

Tortuosity of CV as it extendssuperiorly toward GE junction

Sagittal paramedial view

Flow in CV directed superiorly & away from splenic vein

P-S collaterals / Gastroesophageal collateral

Gastroesophageal collateral veins close to diaphragm

McGahan J et al. Diagnostic ultrasound, Informa Healthcare, 2nd edition, 2008.

Longitudinal view of left liver lobe

Normal umbilical vein anatomy

UV communicates with umbilical segment of LPVTravels down anterior abdominal wall toward umbilicusEventually drains into systemic system via inferior epigastric vein

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Hepatofugal flow within UV

Similar color Doppler view Longitudinal US of LLL

Dilated umbilical vein (10 mm)

P-S collaterals / Recanalized umbilical vein

PUV observed only in hepatic or suprahepatic blockage

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.N Engl J Med 2005 ; 353 : e19.

Sagittal panoramic view

PUV traveling to periumbilical region where it becomes tortuous

P-S collaterals / Recanalized umbilical vein

Caput medusae

Cirrhosis & PHT / Diameter of portal vein

1 Weinreb J et al. Am J Roentgenol 1982 ; 139 : 497 – 499.2 Goyal AK et al. J Ultrasound Med 1990 ; 9 : 45 – 48.Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Diameter: 16.9 mmSign of portal hypertension

Longitudinal view of MPV

Contoversy on normal PV diameter

Up to 13 mm in one study1

Up to 16 mm in another study2

Unusual large PV: good sign of PHT

Normal PV size: do not exclude PHT

Cirrhosis & PHT / Portal vein velocity

Low velocity: good indicator of PHT Normal velocity: do not exclude PHT

Controversy on normal PV velocity

Difficult to rely on velocity for dg Normal mean velocity: 15 – 18 cm/sec

Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.

Shrunken liver & irregular marginVmax: 10 cm/sDiagnosis of PHT

Triplex image of PV

Portal vein pseudoclot – Incorrect velocityCirrhotic patient with portal hypertension

Slower flow in portal veindemonstrated

Velocity scale: 7 cm/s

Rubens DJ et al. Ultrasound Clin 2006 ; 1 : 79 – 109.

Velocity scale: 20 cm/s

Good flow in HA anteriorlyNo flow in adjacent PV

Cirrhosis & PHT / Portal vein flow

Normal flow

Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.

Reversed flow

Advanced PHT

SOS

Porto-systemic shunt

To and fro flow

Advanced PHT

Heart failure

Arterio-portal fistula

Cirrhosis & PHT / To-and-fro flow in PVCardiac cycle

Hepatopetal & hepatofugal with each heart beat Seen before frank hepatofugal flow

Wachsberg RH et al. RadioGraphics 2002 ; 22 : 123 – 140.

Duplex US of LPV during suspended respiration

Cirrhosis & PHT / To-and-fro flow in PVRespiratory cycle

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

On real-time US, these alterations corresponded to respiratory cycle

Transverse color Doppler US of left portal vein

Hepatopetal flow Hepatofugal flow

Causes of to-and-fro flow

Exaggerated pulsatility

Minimum velocity below baseline

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

- Portal hypertension

- Tricuspid regurgitation

- Right heart failure

- Aerterio-portal vein fistula

Cirrhosis & PHT / Reversed flow of PV

Hepatopetal flow in HA & hepatofugal flow in PV

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Not pathognomonic feature of cirrhosis

Severe PHT – Rare

Hepatopetal flow in HAHepatofugal flow in PV

Color Doppler of peripheral liver

Arterial flow above baselinePortal venous below baseline

Duplex Doppler of same area

Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

Cirrhosis & PHT / Reversed flow in PV branches

Patency of the portal vein and superior mesenteric vein

Ultrasound can be used to assess the vascular patency of a potential transplant

recipient. Diffuse thrombosis of the portal and superior mesenteric vein (SMV) is a relative

contraindication to liver transplantation. Portal vein thrombosis requires the modification of surgical technique at the time of transplantation.

PV thrombosis

Partial thrombosis of portal vein

Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.

Black & white ultrasound

Partial echogenic thrombus

Color & pulsed Doppler

Complete filling of main PVobscuring the clot

take care

Portal cavernoma

Gray-scale ultrasound Color & pulsed Doppler

No PV!

Superior mesenteric vein thrombosis

Transverse image of SMA & SMV

http://www.ultrasoundcases.info

SMASMV

Status of transjugular

portosystemic shunt Some recipients may have

undergone placement of a transjugular portosystemic shunt (TIPS) prior to transplantation. The patency of the shunt can be assessed with colour Doppler ultrasound, including Power Doppler.

thrombosis

Cirrhosis & PHT / Prominent hepatic artery

Enlarged HA with tortuous or ‘‘corkscrew’’ appearanceIncreased flow in HA to compensate decreased flow in PV

Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.

Cirrhosis & PHT / Changes of hepatic artery flow

Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.

Decreased diastolic flow

ESLD

Reversed diastolic flow

ESLD

Normal flow

Normal in mostpatients

Cirrhosis often causes narrowing of the hepatic veins with loss of the normal phasic waveform. Intrahepatic

vessels may be indistinct.

Cirrhosis & PHT / Changes of hepatic vein flow

Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.

Triphasic Biphasic

CirrhosisBudd-Chiari syndromeMetastasesAscitesHealthy subjects

Monophasic

CirrhosisBudd-Chiari syndromeMetastasesAscitesHealthy subjects

Damping index of HV waveform

Severe portal hypertension : HVPG > 12 mmHgKim MY et al. Liver International 2007 ; 27 : 1103 – 1110.

Minimum velocity of downward HV

Maximum velocity of downward HVDamping index =

Normal value: < 0.6Severe portal hypertension: ≥ 0.6

Damping index of HV waveform in cirrhosis

DI: 0.26 HVPG: 7 mmHg

DI: 0.72HVPG: 15 mmHg

Kim MY et al. Liver International 2007 ; 27 : 1103 – 1110.

DI of 0.6: Sen 76%, Sp 82, & AUC 0.86 for severe PHT

Caudate lobe The caudate lobe can become enlarged and

surround the inferior vena cava (IVC), which is of relevance in cases of living

donor transplantation.

Presence and extent of hepatocellular carcinoma

Liver transplantation for the treatment of hepatocellular carcinoma (HCC) provides

excellent outcomes with application of the Milan criteria (single nodule < or = 5cm, or two or three nodules < or = 3cm) with 5-year survival rates of 70% and low recurrence

focal mass