Chapter 83 - Lower extremity aneurysms Flashcards
M:F ratio of LE true aneurysms
30:1
Association of AAA with other peripheral aneurysms
Femoral: 50-90%
One popliteal 30-50%
Bilateral popliteal 70%
Chance of bilateral aneurysms in femoral and popliteal
Femoral: 25-50%
Popliteal 50-70%
Rate of femoral or popliteal aneurysm in men or women with aortic aneurysms
14% in men
no association in women
Normal size of CFA
Men 1.0 cm
Women 0.8 cm
Indicated diameter for repair in CFA aneurysm
- 5 cm according to largest reported series 172 patients
3. 5 cm according to Lawrence
Risk for CFA true aneurysms
1) men
2) age >70
3) smoking
4) HTN
Cause of CFA true aneurysm
1) degenerative
2) atriomegaly
3) Behçet
4) Parkes Weber syndrome
5) Wegener granulomatosis
distribution of true aneurysms in the femoral segment
CFA 81%
SFA 14%
PFA 5%
Clinical presentation of true femoral aneurysm
Asymptomatic 30-40%
Pain 30-40%
Lower extremity ischemia (embolization) 65%
Pain associated with femoral aneurysm
localized tenderness
compressive neuropathic pain
leg edema
Indication for treatment of femoral aneurysm
1) all symptomatics
2) > 2.5 cm (controversial, maybe 3.5 cm according to Lawrence)
Natural history of femoral pseudoaneurysm
Less than 2-3cm may thrombose spontaneously
Closure rate higher if less than 1.8 cm
Will not close if on anticoagulation
Duplex Sen and Spe for pseudoaneurysm
Sensitivity 94%
Specificity 97%
Ultrasound guided compression of femoral pseudoaneurysm first introduced in
1991
Ultrasound guided compression of femoral pseudoaneurysm technique
1) compression maintained 10-20 min
2) repeat if flow still present
3) bed rest 6 hours
4) repeat DUS 24-48 hours
Success rate of ultrasound guided compression; what if anticoagulated, time needed to compress and recurrence rate
66-86%
<40% if anticoagulation
Compression time 30-44 min
Recurrence 4%
Contraindication for ultrasound guided compression of pseudoaneurysm
1) ischemic skin
2) infection
3) puncture site above inguinal ligament
4) severe pain
5) large hematoma
Complication types and rate after ultrasound guided compression of pseudoaneurysm
2-4%
1) rupture
2) femoral vein thrombosis
3) femoral artery thrombosis
4) vasovagal
Ultrasound-guided thrombin injection first described by
Cope in 1990’s using angiographic guidance
Kang modified using ultrasound guidance
Thombin MOA
Converts fibrinogen to fibrin
Clot formation bypassing heparin/warfarin effects
How to prepare thrombin
Bovine or human thrombin mix with NS
Ultrasound-guided thrombin injection technique
1) US to identify cavity
2) local
3) puncture with 22 or 25 gauge needle
4) inject slowly via 3ml syringe over 10-15 seconds (1000 IU/ml): total dose ~ 1000 Units
5) bed rest 1 hour
6) repeat US 24 hours
Ultrasound-guided thrombin injection success rate
96-100%
second injection in 7% cases
Contraindication to bovine thrombin
1) allergy
2) infection
3) pregnancy
Relative
1) wide channel/neck
Indication for open surgical repair of femoral pseudoaneurysms
1) ruptures
2) failure or contraindication to compression or thrombin
3) skin ischemia
4) AVF
Open repair techniques for femoral pseudoaneurysms
1) direct repair
2) patch angioplasty
Complication following open repair of femoral pseudoaneurysms
Wound complication: 4-8%
Mortality 2.9%
SFA aneurysm (isolated)
Elderly men age 75.7 years
middle third of artery
mean diameter at presentation 8.4 cm