Mesenteric vessels Flashcards
(89 cards)
1
Q
normal celiac duplex
A
<200 cm/sec PSV normal
2
Q
normal SMA duplex
A
<275 cm/sec PSV normal
3
Q
normal renal duplex
A
<180 cm/sec PSV normal
<3.5 RAR
<0.75 RI
4
Q
celiac artery >75% stenosis
A
> 200 PSV
5
Q
celiac artery >50%
A
EDV >55`
delayed upstroke in splenic and hepatic
6
Q
SMA >75% stenosis
A
> 275 PSV
7
Q
SMA >50% stenosis
A
> 45 EDV
8
Q
normal TIPS duplex criteria
A
portal flow 30-40
velocities in shunt 90-200
PSV down with inspiration
9
Q
TIPS obstruction duplex criteria
A
PSV<90 or >200,
PSV down by 50 or more comparing to shunt
point to point increase in PSV by more or equal to 50
portal vein velocity <30
hepatofugal flow in portal vein
absence of doppler signal or color flow in TIPS
10
Q
hepatofugal flow
A
away from the liver
abnormal in portal vein, normal in hepatic veins
11
Q
how do you calculate resistive index in the kidney
A
(PSV - EDV)/PSV
12
Q
what is a normal resistive index in the kidney
A
<0.6
13
Q
what is an abnormal resistive index in the kidney
A
> 0.7
14
Q
What is the definition of parenchymal diastolic / systolic ratio?
A
EDV/PSV
15
Q
what is the abnormal parenchymal diastolic / systolic radio in kidney
A
<0.2
16
Q
what is the definition of RAR for the kidney?
A
PSV renal artery / PSV aorta
17
Q
what is the normal RAR for the kidney?
A
<3.5
18
Q
normal renal artery PSV
A
<180-200cm/sec
19
Q
what are the normal characteristics of renal artery duplex
A
short systolic upstroke
rapid deceleration
diastolic forward flow
early compliance peak
20
Q
In stent SMA restenosis
A
> 445cm/s
21
Q
In stent celiar artery restenosis
A
> 289cm/s
22
Q
Goldblatt experiment - unilateral disease
A
1 clip 2 kidneys
RENIN DRIVEN: continued renin release from bad kidney, but good kidney can excrete excess volume. Angiotensin II derives renovwwcular HTN
Initial decline in GFR with ACE-I but long term recovery
23
Q
renal artery size
A
5mm
24
Q
criteria for >60% renal artery stenosis?
A
PSV >180mm/s
renal artery/aortic PVS ratio>3.5
resistive index >0.8
25
renal stenting trials
STAR
ASTRAL
CORAL
26
What does STAR trial say
140 patients criteria: >=50% stenosis plus impaired renal function
only patients with medically controlled BP
no difference in primary endpoints of 20% or more decline in renal function
27
What does ASTRAL trial say
806 patients
stenting rendered small improvement of renal function but no change in BP
23 patients had serious complications after procedure
no protocolized medical therapy
mild CKD and HTN - 40% of patient’s without severe RAS
Patients who definitely needed a stent were excluded
28
What does CORAl trial say
prospective, 947 patients
Endpoints: major CV events and renal failure
RAS >80% or 60% with pressure gradient >20 and HTN on 2 or more meds
stenting showed no benefit
29
Technique of stenting renal artery
sized to normal artery segment
length: lesion +1-3mm on each side
if ostial: 2mm in the aorta
Use BES to provide radial force
30
what are the duplex changes in median arquate ligament
celiac artery velocities are ELEVATED with EXPIRATION (artery is compressed on Expiration)
31
what's the other name of kidney resistive index?
Pourcelot's index
32
criteria for <60% renal artery stenosis?
PSV>200 but RAR <3.5
33
duplex characteristics of hepatic vein flow
bidirectional
hepatofugal
pulsatile
similar to proximal IVC
34
what are the peaks and valleys of hepatic vein flow on duplex?
A peak - RA contractility
S valley - filling of RA during ventricular systole
V small peak- RA overfilling just before tricuspid valve opens
D valley - filling of RA during ventricular diastole
35
what is the characteristics of cirrhosis on duplex
loss of hepatic vein variability
36
what are the duplex characteristics of distal IVC
```
reciprophasic flow
(continuous cephalad flow with respiratory variation)
```
37
what vessels have reciprophasic flow
```
distal IVC
portal
splenic
renal
SMV
```
38
normal aortic velocity
40 - 100 cm/s
39
what size discrepancy indicates arterial lesions in kidney
>1.5cm
40
normal portal vein size
<1.3 cm
41
what does pulsatile portal vein flow indicate
tricuspid regurgitation
| right heart failure
42
Goldblatt experiment
1. decreased arterial flow to one kidney (by narrowing the artery) activated RAA system. circulating angiotensin II increases blood pressure and total systemic vascular resistance. It has negative feedback on the non-malperfused kidney and decreases renal production there. Renin production increased in malperfused kidney causes hypertension due to high levels of angiotensin II (to maintain blood flow to the affected kidney) and causes pressure diuresis (mounted by the non-malperfused kidney)
2. solitary malperfused kidney is unable to achieve the pressure diuresis required to handle aldosterone - induced Na and H20 retension --> volume expansion
43
Winslow pathway
Internal thoracic artery --> superior epigastric --> inferior epigastric --> external iliac
44
Visceral pathway
superior rectal --> obturator artery or internal pudendal artery --> medial circumflex artery
45
collateral pathway between celiac and SMA
arch of Bueller
46
SMA syndrome
compression of duodenum between SMA and aorta
| acute angle between SMA and aorta (normal 45* --> less than 30* indicates the syndrome)
47
Quincke's triad
bleeding into biliary tree: upper abdominal pain, upper GI bleed and jaundice
48
zones of SMA
1. aorta to IPDA
2. IPDA to mesocolic
3. mesocolic to distal branches
4. distal branches
49
Integrated injury hypothesis in acute mesenteric ischemia
1. Hypoxia - injury reflects time and severity of hypoperfusion. Central mechanism is disruption of intercellular tight junction with increased capillary permeability
2. reperfusion - cytokines and ROS upregulate cell adhesion molecules. Accentuate neutrophil aggregation and secondary injury
50
Mortality in acute mesenteric ischemia
85%
51
Source and site of embolic AMI
Cardiac source
SMA preferred site - 15% Ostia and 50% distal
52
Which side incision for SMA embolectomy
Transverse
53
What is the most common site for In site thrombosis as a cause of AMI
Origin of SMA
54
Causes of mesenteric venous thrombosis
```
Prothrombic state
Hematologist disorder
Abdominal inflammatory disorder
Cirrhosis and portal hypertension
Trauma, dehydration, and decompression sickness
```
55
What vasodilators can be used as an infusion for NOMI
```
Tolazoline bolus (25mg)
Papaverine infusion (60mg/hr)
```
56
Operative indications for NOMI
Pneumoperitoneum
Peritoneal signs that persist despite vasodilators
Leukocytosis
Ihemorrhagic shock
57
What’s the bimodal presentation of chronic mesenteric ischemia
1. elder patients with advanced atherosclerosis and high OR risk. Mean age 75, no gender difference
2. younger patients with strong tobacco history and better poerative risk, mean age 55, female > male
58
When is open surgery indicated for mesenteric occlusive disease
```
Acute ischemia with peritoneal signs
Unfavorable lesion (flush occlusion, long stenosis, problematic angulation)
Aortic disease requiring operation
Young patient (<50)
After railed angioplasty
```
59
Right rental artery exposure
Medial to IVC (graft posteromedial to IVC) or distal exposure with ascending colon medial rotation and mobilization of duodenum (graft anterior to IVC)
60
Left renal artery exposure
Proximal exposure by ligation of IMV, gonadal, adrenal vein wit mobilization of 3rd and 4th portion of duodenum; distal exposure by ,mobilization of splenic flexure and medial rotation of descending colon
61
In stent restenosis >70% in SMA
Psv >412
62
In stent restenosis >70% in celiac
Psv>363
63
Rental duplex technique
Obtain aortic PSV proximal to visceral segment
Locate main renal landmarks
Examine main renal artery from origin to renal parenchyma with recording of waveforms
Examine inteapsrenchymal renal arteriole flow
Document kidney length
64
Celiac artery detailed exposure
Midline or chevron incision
Enter through gatrohepatic ligament
Retract left lobe of the liver cephalon and esophagus to the left
Body of the pancreas lies along the inferior border
65
How to access SMA open?
1. Lift the mesocolon and identify middle colic artwru
Go down to the SMA
As it travels over the fourth portion of the duodenum
2. Elevate the transverse mesocolon
Mobilize the fourth portion of thenduodenum
Cephalon retraction of the inferior border of the pancreas
66
Where do you tunnel the obturator bypass
ANTERO MEDIAL!!! Through the obturator canal
67
Exposure of PT
Media incision 1 cm from the tibia
Bend the knee to relax the gastrocnemius muscle
Take down tibial insertion of the soleus
68
Proximal peroneal artery approach
Medial leg, just like PT
69
Middle third peroneal approach
Latest approach with partial fobulectomy
70
Goldblatt experiment - bilateral disease
1 clip 1 kidney or 2 clips 2 kidneys
VOLUME DRIVEN - neither kidney can excrete excess volume; body settles down to a volume overloaded homeostatic state (diuretics)
Aldosterone mediated renovawcular HTN
Significant incidence of neuropathy as overall GFR drops
Acute renal failure after starting ACE I concerning for bilateral renal involvement
71
Who should get a rental PTA or stent
1. FMD/pediatric - early intervention, best outcomes of creatinine and kidney size normal, and HTN <8 years
2. Severe hypertension not medically controlled
3. Flash pulmonary edema (early intervention)
4. Ischemic nephropathy - documented proteinuria, larger pole length and resistive index less than or equal to 0.8
72
Treatment of pediatric renal congenital hypoplastic syndrome
Endovascular has a very high recurrence rates
Direct Surgical reconstruction best option - medialization of kidney with direct reimplantation or bypass with hypogastric artery
73
Griffiths point
SMA and IMA
| splenic flesher
74
Sudeks point
Between IMA and hypogasteic branches
| Rectosigmoid
75
Do you explore midline supramesocolic blunt hematoma
Yes
76
Do you explore midline supramesocolic penetrating hematoma
Yes
77
Do you explore midline inframesocolic blunt hematoma
Yes
78
Do you explore midline inframesocolic penetrating hematoma
Yes
79
Do you explore lateral perinephric hematoma blunt
No
80
Do you explore lateral perinephric hematoma penetrating
Selective
81
Do you explore blunt pelvic hematoma
No
82
Do you explore penetrating pelvic hematoma
Yes
83
Zones of SMA
1. Between the aortic origin and inferior PDA
2. Between inferior PDA and middle colic artsy
3. Distal to the middle colic artery
4. Segmental intestinal branches
84
How many splanchnjc aneurysms present as emergencies
22%
85
Incidence of splenic artery aneurysm
60% of all mesenteric aneurysms
F:m 4:1
Medial degeneration, inflammation pancreatitis related, trauma, atherosclerosis
86
What’s the incidence of different splanchnjc aneurysms types
```
Splenic 60%
Hepatic 20%
SMA 5.5%
Celiac 4%
Gastric and gastroepiploic 4%
Jejunal, ileal and colic 3%
GDA 1.5%
PDA 2%
Renal 0.1%
```
87
Best study to diagnose MVT
CTA
88
Segmental arterial mediolysis
Rare, acute, often self limiting
Mean age 60, no gender difference
Visceral arteries at the adventitial- medial junction
Arterial dilatation, aneurysm, hematoma, stenosis and occlusion
Overstimulation is Alfa-1 receptors May lead to vasoconstriction
89
Most common location of hepatic aneurysm
80% extrahepatic in common hepatic artery
