Date post: | 07-May-2015 |
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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