Week 11 BPG duplex exam Flashcards
What are 4 LE BPG indications?
- Disabiling claudication
- Rest pain
- Ulceration
- Gangrene
What are the 5 treatments for LE arterial obstruction?
- Control risk factors
- Excersise mangement
- Thromboectomy/embolectomy
- Angioplasty & stents
- BPG
What are the 7 types of LE BPG?
- Aorto-bi-femoral
- Aorto-iliac
- Aorto-fem.
- Fem-Fem.
- Fem-pop
- Profunda fem-pop.
- Fem-distal.
What are the 4 types of grafts for an aorto-iliac obstruction?
- Aorto-bi-fem
- Aorto-fem
- Fem-fem
- Axillo-fem.
What is the most common type of graft?
fem-pop.
What is a jump graft?
If a graft becomes occluded, another graft is placed above occluded location.
What is an anastomosis?
Point where the native artery meets the graft.
What are the 3 types of anastomosis?
- end to end
- end to side
- side to side
What is an end to side anastomosis?
Bypass graft
What is a end to end anastomosis?
interposition graft
What is a side to side anastomosis?
It is used to connect an artery to vein for a dialysis fistula
What is a conduit?
A tube to channel fluid to another location.
What are the 4 types of conduits?
- Veins→GSV, arm veins, cytopresevered veins.
- Superficial fem. vein (extremely rare)
- PTFE doubline (polytetraflourthylene)
- Dacron
What are the 3 types of GSV bypass grafts?
- insitu
- reversed
- transposed
Describe “insitu” GSV BPG?
- Native course of GSV intact so superficial
- Tapered size: Large proximally to small distally.
- Valvutome: cuts valves
- Branches are tied off or AVF occurs
Describe “reversed” GSV bypass grafts:
- May be placed deeply along native course of artery
- Tapered size small proximally to large distally.
- Valves lay along the wall.
Describe “transposed” GSV BPG?
Not reversed, but moved.
What are the 3 basic principles of bypass graft patency?
- Good inflow
- Good conduit
- Good outflow.
What is the purpose of BPG survelliance?
To identify potentially fixable graft-threatening problems prior to graft failure.
What has fixing graft-threatening problms prior to failure proven?
Increase the patency rate of grafts over post-occlusion interventions.
Name 9 BPG problems:
- Intimal Hyperplasia
- Athersclerosis
- Poor inflow and outflow.
- Incomplete valve lysis
- Intimal flap
- Twist/kink in graft
- Extrinsic compression on graft
- Hypercoaguable state
- Infection.
What are the issues associated with PTFE?
- Athersclerosis in inflow & outflow vesseles
- Occlusions without warning.
Why are velocities typically lower in PTFE grafts?
B?C they are typically 6mm in diameter, which is larger than the typical 4 mm veins.
What are someimportant things to include in a BPG survellience patient history?
- Symptoms since last exam.
- Typer of graft placed.
- ANy known occluded graft
- Aprrox. age of graft
How do you identify a PTFE graft on duplex?
- Characteristic double line when vein is horizontal on image.
- May have ultrasonic shadow if new (<48hrs) due to air in the walls.
Which graft is easier to identify when it is occluded?
PTFE
look for shadows
How should you identify a graft in the prox-mid thigh (fem-pop)?
Transverse.
While scanning inflow, why do you move transducer proximally?
- Overview of inflow, past anastomosis.
- Look for narrowing, color mosaic.
Where and how should you place doppler SV in inflow artery in long?
- ABove prox. anastomosis.
- Scroll through inflow artery and past anastomosis into prox. graft.
Graft is usally most ________ artery.
Superficial
Fem-pop may be anastamosed to what?
AFB or native artery just below AFB.
Flow patterns (flow velocity and waveform) differe depending on what?
Geometry
Distrubed flow patterns, low velocities are due to?
widening.
What is the usualy velocity in a normal graft of <4mm in diameter?
>45 cm/s
Larger grafts=_________velocities.
Lower
What type of waveform does a new graft have?
Hyperemic waveform pattern.
What type of waveform does a graft older than >2 months present?
Triphasic waveforms.
hat kind of velocities does a reversed vein graft have?
Higher velocities @ proximal end (smaller end)
What type of velocities do “insitu” vein grafts have?
Higher velocities at distal end.
What type of velocities does a PTFE graft have?
Similar velocites throughout.
If an AVF is formed distally , what typeof waveform will it present?
Hyperemic waveform pattern.
What should you look for in a graft body duplex exam?
- Focally increwase velocities
- FLow disturbances
- Mosaic coloring
- Color narrowing
- Abnormalities
What is a distal anastomosis?
Point where graft meets native artery
What are the 3 tips to scan a distal anastomosis?
- Multiple views
- Tramsverse to see two arteries join.
- Larger graft→Smaller artery.
Where does velocity increase in an anastomosis?
Usually @ toe of anastomoses.
What is an increased velocity change in an outflow artery caused by?
Size changes.
Flow may be _____ in the _____ artery _____ to the anastomosis.
- Reversed.
- Outflow.
- Proximal.
What images should you obatin with a doppler for a BPG duplex scan?
- Inflow artery
- Prox. anastomoses
- Past. prox. anastomoses
- Upper thigh, mid thigh, distal thigh.
- Knee
- Prox. calf, mid calf, distal calf.
- Prox to distal anastomoses.
- Distal anastomoses
- Outflow artery
Where should you scan in a BPG stenosis duplex exam?
- Pre-stenosis (prox to stenosis)
- @ stenosis (point of highest velocities)
- Post-stenosis
Obtain color and B-mode in trans and long.
What does an early valve leaflet regression indicate?
Technical problem
What does 1st year valve leaflet regression indicate?
Intimal Hyperplasia
What does a late (>2 yrs) valve leaflet regression indicate?
Athersclerosis (inflow or outflow)
Is an occlusion the entire or partial graft?
Entire.
What is the diagnsotic criteria for a BOG duplex scan?
- Focally high velocity with post-stenotic turbulence
- Very low velocities (<45 cm/s)
- If no diastolic flow suspect poor outflow
- Significant change in ABI’s
What is considered a “severe” stenosis?
75%
Overall graft velocity may_____ prox. and distal to the stenosis.
Decrease.
How would waveforms look roximally and distally to a severe stenosis?
Proximally→staccato
Distally→monophasic
What is the threshold for intervention?
Ratio: >3.5
PSV: >300
ABI: >.15
What are some other pathology in BPG duplex exam?
- Pseudoaneurysm
- AVF
- Fluid→hematoma, infection, seratoma.
- Mass
