Chapter 14: Miscellaneous Conditions/ Tests (2%) Flashcards
What is an AV fistula
abnormal connection between high pressure arterial system and low pressure venous system
AV fistulas can be
congenital or traumatic
If a fistula is close to the heart what increases
potential for cardiac failure
a fistula located peripherally is more likely to cause
ischemia
AVF may involve
prx and dst arteries/veins as well as collaterals
Proximal arterial flow (prox to AV fistula)
increase diastolic flow because fistula reduces resistance
Depending on size of fistula, arterial flow distal to AV fistula may
resume its normal triphasic pattern or be somewhat reduced
Flow throughout the AV fistula
higher velocities
low resistance
Venous outflow of AV fistula
takes on flow quality of fistulas low resistant pulsatile flow
Compartment syndrome
compression of tibial arteries due to swelling
leads to necrosis of muscle
compartment syndrome can be caused by
repair of tibial artery (from trauma or occlusion)
compartment is bound by bone, fascia and interosseous membrane that does not allow for expansion
pts with compartment syndrome present with
severe pain
tenderness
foot drop
treatment for anterior compartment syndrome
fasciotomy (cutting of fascia to relieve pressure)
Treatment for Pseudoaneurysms
US guided compression
US guided thrombin injection
US guided compression for pseudos technique
compression of 10-15 min with short rest period performed with MD present
monitoring of distal perfusion necessary
length of time varies
US guided compression for pseudo contraindications
inability to uniformly compress neck
pt anticoagulated
multiple communicating channels
key to success of compression of pseudo
neck between native artery and PSA must be uniformly and completely compressed
US guided thrombin injection of PSA contraindications
allergy to thrombin or bovine
infection in groin
ischemia of overlying skin
short/wide neck
Popliteal artery entrapment syndrome is when
pop artery is compressed by medial head of gastrocnemius muscle or fibrous band
pop artery entrapment syndrome is found commonly
in young men
patients with pop artery entrapment syndrome present with
symptomatic arterial occlusion or intermittent claudication
Epigastric artery is
terminal branch of internal mammary artery
epigastic arteries and perforators
take blood to rectus abdominis muscle
TRAM flap
rectus abdominis muscle, sub q fat, arteries, perforators, overlying skin
reason for mapping epigastric artery
surgeon wants to use the best arterially supplied muscle section for TRAM flap for autogenous breast reconstruction
Internal mammary artery (internal thoracic artery) arises
off arch of subclavian artery
descending posterior side of upper 6 ribs
1cm from sternum
reason for mapping internal mammary artery
free flaps for breast reconstruction
graft left anterior descending coronary artery
radial artery mapping is used to
determine suitability for use as graft for coronary artery bypass
radial artery mapping technique
assess patency of palmar arch (allen test)
pt does not make a fist, use PPG with radial compression instead
PPG pulsations should continue with rad art compression, if they do not do not proceed because removal of artery will compromise hand
measure diameter of rad artery
Vein mapping is used to determine
use for coronary bypass
use for dialysis access/graft
vein mapping technique lower extremity
GSV used (sometimes lesser saf) mapped prx to distal measurements obtained along extemity high mid distal thigh knee behind knee prx mid dist calf and ankle
upper extremity vein mapping
cephalic or basillic are used
measurements prx bicep, above elbow, elbow, forearm prx mid dist and wrist
vein mapping general techniques
tourniquet used to expand vessel
compressibility assessed
outer to outer edge diameter measurement along extremity
vein length cm obtained
vein dimension for vein mapping
at least 2-3mm
basilic vein is often larger than cephalic
thoracic outlet syndrome is
neurovascular bundle compression by should structures
occurs in certain arm positions
most common compression of thoracic outlet syndrome
compression of brachial plexus (97%)
small percentage due to subclavian artery or vein
symptoms of thoracic outlet syndrome
numbness/tingling of arm
pain/aching of shoulder or forearm
upward position increase pain/symptoms
25-30% of people are asymptomatic
ruling out thoracic outlet syndrome
PPG and doppler
arm resting and placed in various positions
thoracic outlet test normal and abnormal results
normal: resting waveforms maintained
abnormal: flattening of waveforms in one or more positions
