Portal Venous Flashcards
(83 cards)
1
Q
TIPS
A
therapeutic porto-sytemic shunts
2
Q
portal venous system
A
vessels involved in drainage of capillary beds of GI tract and spleen to the liver
3
Q
liver receives blood from
A
PV- deoxygenated
HA - oxygenated
4
Q
pressure of portal blood are
A
lower than in other organs
5
Q
portal HTN most commonly due to
A
liver cirrhosis
6
Q
liver cirrhosis can be due to
A
EtOH or viral
7
Q
morbidity from PHTN
A
bleeding from GE varices
liver failure
8
Q
hepatic blood flow
A
HVs drain into IVC
9
Q
blood from PV branches pass through
A
cavities between hepatocellular sinusoids
10
Q
blood flow from HA
A
mixed in sinusoids to supply hepatocytes with oxygen
11
Q
mixture of blood HA and PV
A
percolates through sinusoids, collects in central vein, drains into HV -> IVC
12
Q
PV supplies _____ blood to liver
A
70-75%
13
Q
HA supplies _____ blood to liver
A
25-30%
14
Q
MPV formed by confluence of
A
SMV, SV
15
Q
MPV terminates at
A
porta hepatis
16
Q
MPV courses
A
SUP, to right, behing 1st portion of duodenum
17
Q
HA flow direction
A
hepatopedal
18
Q
HA flow pattern
A
low resistance
19
Q
HA PSV
A
30-40 cm/s
20
Q
HA EDV
A
10-15 cm/s
21
Q
HA RI
A
0.6 -0.7
22
Q
PV flow
A
low velocity, hepatopedal
23
Q
PV flow velocity
A
10-40 cm/s
24
Q
PV flow profile
A
slightly phasic: increase with inspiration, decrease with expiration
25
measure MPV diameter where
crosses IVC
26
HV normal flow
pulsatile, phasic: increase with inspiration, decrease with expiration
27
HV normal flow pulsatile due to
transmission of RA pulsations
28
HV velocity
22-39 cm/s
29
left gastic vein aka
coronary vein
30
PV tributaries
left gastric vein, IMV
31
collateralization results in
normalization of PV flow and calibre
32
PHTN when portosystemic pressure gradient is
> 10 mmHg
33
increase in portosystemic pressure gradient due to
increase in resistance to flow within liver
34
increase in resistance to flow within liver can be secondary to
morphological abn, circulatory vasoconstrictors
35
hyperdynamic circulation
increased liver congestion, worsened portosystemic gradient
36
prehepatic causes of PHTN
thrombosis of PV or SV
extrinsic compression of PV
congenital atresia of PV
37
intrahepatic causes of PHTN
cirrhosis
hepatic fibrosis
lymphoma
38
post hepatic causes of PHTN
IVC obstruction
| HV obstruction
39
PV changes with PHTN
increased MPV diameter
loss of respiratory variation (phasicity) - waveform flattens
decreased velocity - bidirectional, then reverses
40
HA changes with PHTN
flow increases as PV flow decreases, HA becomes dilated and tortuous with cork-screw appearance
41
SV and SMV changes with PHTN
diameter will not increase with deep inspiration
42
vascular changes with PHTN
portosystemic collaterals
43
normal gradient of PV
< 7 mmHg
44
mild pHTN
7-10 mmHg
45
PHTN resulting in GE varices
10-12 mmHg
46
PHTN with increased risk of variceal bleeding
> 12-15 mmHg
47
most specific US finding for PHTN
portosystemic collaterals (varices)
48
incidence of varices is related to
severity of liver disease
49
risk of bleeding in GE varices directly related to
portosystemic gradient
50
________ % of varices can be visualized
65-95 %
51
cirrhosis volume redistribution
right lobe - smaller
| increased size of caudate lobe + lateral segment of Left lobe
52
cirrhosis appearance
coarse, nodular surface, focal masses, heterogeneous, ascites, splenomegaly, Gamna-Gandy nodules
53
Gamna-Gandy nodules
splenic siderotic nodules
54
Gamna-Gandy nodules
focal deposits of iron and calcium in spleen, echogenic, less than 1 mm
55
PHTN treatment
pharmocological therapy - beta blockers
endoscopic procedures - scherotherapy, variceal ligation
surgical - decompressive shunts, devascularization procedures, liver transplant
56
TIPS
transjugular intrahepatic portocaval shunt
57
TIPS - what is it
stent inserted between the hepatic inflow (portal system) and hepatic outflow (HV or IVC)
58
TIPS for who
pt with persistent uncontrolled bleeding from esophageal varices
59
TIPS contraindications
```
HCC - esp in right lobe
polycystic liver disease - lack of adequate liver parnchyma to keep stent in stable position
acute infection
biliary obstruction - risk of bile leak
PV thrombosis
severe hepatic encephalopathy
inadequate liver reserve - fulminant liver failure due to ischemia
severe right heart failure
```
60
TIPS is effective for
reducing ascites, preventing hemorrhage from GE varices, improving quality of life for patients with cirrhosis
61
fulminant
severe and sudden onset
62
TIPS causes of acute morbidity
hemorrhage, cardiopulmonary failure (due to volume overload), infection, hepatic encephalopathy
63
hepatic encephalopathy
toxic metabolites present in blood stream due to improper liver function. (liver not removing toxins, filtering blood properly)
64
velocities with TIPS are
higher
65
TIPS flow direction
hepatopetal at portal end (into liver)
| hepatofugal at hepatic end (towards IVC)
66
LPV and branched of RPV direction
hepatofugal - towards TIPS
67
normal flow velocity in TIPS
> 90 cm/s up to 200 cm/s, turbulent
68
normal flow velocity in PV with TIPS
> 40 cm/s
69
velocities in HV less than ___ suggest impending failure
30 cm/s
70
velocities at portal end of shunt less than ___ suggests stenosis of concern within TIPS
50 cm/s
71
post TIPS waveform
monophasic, slightly pulsatile, moderate turbulence- spectral broadening
72
PSV in shunt should be
50-60 cm/s
73
PSV in shunt can be up to
90-120 cm/s, can be pulsatile
74
new onset of ascites indicates
stenosis in shunt
75
recurrent varices suggests
stenosis in shunt
76
hepatopetal flow in LPV despite well-functioning shunt indicates
recannalized umbilical vein
77
reversed flow in HVs suggests
stenosis (flow directed towards TIPS)
78
most pts with stenoses are
asymptomatic
79
stenoses usually occur at ___ end of stent
hepatic end
80
TIPS occlusion may be indicated by
varices, ascites, pleural effusion
81
late TIPS stenosis or thrombosis
pseudointimal hyperplasia, turbulent blood flow
82
velocity at portal end should be ____ to velocity at hepatic end
similar
83
PV velocity post TIPS
at least 30 cm/s; 37-47 cm/s
