Aneurysm Flashcards
Aneurysm
localised dilation >1.5 x normal size of artery segment
True aneurysm
Involves all 3 layers of arterial wall
False aneurysm
Not involving all arterial layers, actually compared thrombus/layer of fibrous tissue
Cause of aneurysm
- Artherosclerosis 90%
- Familial
- Infective
- Connective Tissue disorder
- Traumatic/Iatrogenic
- Inflammation
Definition of AAA
External diameter >3cm
Etiology of AAA
- Artherosclerosis 90%
- Infection
- Connective Tissue Disease
- Inflammation
- Traumatic / Iatrogenic
Epidemiology of AAA: Percentage of AAA
1) infrarenal
2) associated wtih atherosclerosis
3) associated with other peripheral aneurysm
1) 95%
2) 95%
3) 20%
Triad of rupture AAA
Pulsatile mass
Abdominal pain radiating ot back
Shock
Risk factors for AAA
Male
Age
Smoking
Family Hx
(DM and female reduced risk)
Sequelae of ruptured AAA.
Percentage
1) do not reach hospital
2) not fit for surgery
3) anterior rupture, die before arrival
4) operative mortality
1) 50%
2) 30%
3) 20%
4) 50%
Management of ruptured AAA
Resuscitation according to ATLS, aim for permissive hypotension
Reassessment of responsiveness to resuscitation
Decision for CT or OT
Preparation for OT
OT procedure
1) Name a few predictive scores for AAA
2) Common parameters
1.
Glasglow Aneurysm Score
Hardman Index
RAAA-POSSUM
Edinburgh Ruptured Aneurysm Score
- Age, creatinine, Hb, GCS, SBP
Laplace’s law
Wall tension = pressure x radius
*Thus larger radius, easier for rupture
Early complications of AAA
Anastomotic bleeding
Thromboembolism to LL (trash foot)
Renal damage
Ischemic bowel
Spinal cord ischemia
Late complications of AAA repair
Infected graft
Sexual dysfunction
Aorto-enteric fistula
Anatomical requirements for Endovascular Grafting
Proximal landing zone ≥15mm
Angulation of neck < 60 degrees
Neck diameter ≤ 3.2cm
Distal landing zone ≥10mm
Distal fixation diameter 7-20mm
<25% of circumference with thrombosis and calcification
Endoleak
1) Type 1
2) Type 2
3) Type 3
4) Type 4
5) Type 5
1) inadequate proximal and distal sealing
2) patent branch vessel
3) defect in fabric of graft
4) Leaking through porosity of graft
5) endotension
Evidence for EVAR vs open repair
DREAM
EVAR I
OVER
EVAR II
Evidence for EVAR vs surveillance in smaller AA
CAESAR (2011)
PIVOTAL trial (J Vas Sur 2010)
Surgery for small asymptomatic abdominal aortic aneurysm (Cochrane 2012)
Surveillance after EVAR
1) Aim
2) If no endoleak
3) If endoleak
1) identify endoleak, sac expansion, graft migration
2) Yearly duplex USG + plain XR
3) CTA
Evidence for screening for AAA
UK MASS trial (2002 Lancet)
Indication of treatment for thoracic aortic aneurysm
- Size > 6cm
- Symptomatic
- Enlarging
- Aortic valve incompetence in ascending aortic aneurysm
Indication for treatment of popliteal aneurysm
- >2cm
- Symptomatic
Margins of the popliteal fossa
Superior: supracondylar line of femur
Inferior: soleal line of tibia
Superiolateral: bicep femoris
Superior-Medial: semitendinous
Inferior lateral: lateral head of gastrocnemius
Inferior medial: medial head of gastrocnemius
Contents of the popliteal fossa
Popliteal artery
Popliteal vein
Treatment options for popliteal aneurysm
- Conservative
- Surgical Bypass
- Aneurysm exclusion and bypass
- Inline reconstruction
- Endovascular stent grafting
Approaches for surgical repair of popliteal aneurysm
1) Medial approach (for aneurysm exclusion/ligation and bypass)
2) Posterior approach (inline reconstruction)
Definition of femoral artery aneurysm
Aneursym >2cm
Indication for surgical repair fo femoral artery aneurysm
1) symptomatic
2) >3cm
Percentages for femoral artery aneurysm
1) isolated CFA
2) involving bifurcation
3) isolated SFA/ Profundus artery aneurysm
4) concomitant AAA/popliteal aneurysm
1) 40%
2) 50%
3) 5%
4) 50%
Management of infected pseudoaneurysm
- If non-IVDA: ligation + bypass
- If IVDA: Triple ligation adn resection of aneurysm
Indication for surgery in asymptomatic iliac artery aneurysms
> 3-4 cm
Via exclusion and bypass
Triple ligation
- Groin incision
- Dissection down to extraperitoneal plane
- Locate and control external iliac artery
- Axial incision along fmoeral artery
- Identify and clamp superficial and profunda femoris artery
- Ligation of tripe (CFA, SFA, Profunda femoris artery), if fail, for ligation of EIA
- Debridement of necrotic tissue
- Layered closure of groin wound
- Postop observation of leg viability
EVAR 1
Elective EVAR vs open in AAA> 5.5
Lancet
Primary outcome: 30-day mortality, 4 years and 8 years FU
Result:
- Significantly better 30 day mortality
- At 4 years, lower aneurysmal related mortality in EVAR
- At 8 years, no difference in aneurysmal related survival. High graft related complications and re-interventions in EVAR
OVER trial
Elective EVAR vs open (US)
Patient: AAA> 5 or 4.5cm with rapid growth
Outcome: 30 day mortality, 2 year mortality
Result: EVAR better than open for 30 day mortality, but at 2 years, no difference
EVAR II
EVAR vs no intervention in non-fit patients
Primary outcome: 30 day mortality
Result: EVAR does not decrease all cause mortality, higher graft related complications +mreintervention, more costly
Conclusion: non surgically fit patients should have no intervention
DREAM
Elective EVAR vs open
NEJM 2005 RCT
Result: no difference in aneurysmal related mortality, survival advantage of EVAR no sustained beyond first postoperative year
IMPROVE trial
Ruptured AAA: EVAR vs Open
Primary outcome: 1 year all cause mortality
Result: no difference in all cause mortality or reintervention. EVAR shorter hospital stay, higher QALY, lower cost
UK Small Aneurysm Trial
Asymptomatic AAA from 4- 5.5 cm
Intervention: early elective open repair vs USG surveillance
Conclusion: Early repair has no survival benefit, 30day mortality of 5.8%
ADAM trial
Open repair vs surveillance in 4.0-5.5cm AAA
Conclusion: no difference in survival up to 8 years
Evidence for ruptured AAA
IMPROVE
AJAX
ECAR
AJAX
Amsterdam Acute Aneurysm Trial
Multicenter RCT
EVAR v Open repair for rAAA
Outcome: application rate of EVAR
Conclusion: 45% applicable for EVAR, but applied in less
ECAR trial
French multicenter RCT
EVAR vs Open repair for rAAA
Outcome: 30day and 1 year mortality
Conclusion: similar mortality, EVAR associated with less severe complications and less consumption of hospital resources
