Chapter 73 - EVAR techniques Flashcards
Examples of positive fixations of endografts
1) hooks 2) anchors 3) barbs 4) staples
Column support of endograft
Straddle Aortic bifurcation
Friction fixation
outward radial force
Risk factors for limb thrombosis post EVAR
1) iliac injury 2) calcification 3) tortuosity 4) excessive oversizing
Aorto-uni-iliac grafts currently available
1) ReNu 2) Endurant
Relative indication for aorto-uni-iliac graft
1) small < 15 mm distal aorta 2) severe unilateral iliac occlusive disease 3) secondary treatment of migration of short body graft
Slice diameter on CTA cutoff for planning regular and fen grafts
Regular < 2.5 mm Fen < 1 mm
Non-contrast CT for EVAR planning can miss these things
1) laminated thrombus at neck 2) patency of side branches 3) occlusive iliac disease
Alternative to CTA in renal failure patients
1) IVUS 2) CO2
Sizing measurement technique
Adventitia to adventitia except for Gore (intima to intima based on their trial)
Oversizing amount
10-20% proximal neck (3-4 mm larger)
EVAR size range currently can accommodate this range of aortic necks
18-36 mm graft for 16-32 necks
Risks of oversizing and general cutoff
20% risk of pleating
Conical sizing how to do
Split the difference Cannot use endo if > 4 mm change in a 15 mm neck
Shortest main body graft and its lengths
Endurant II Ipsi 103 mm Contra 80 mm
Iliac diameter oversizing amount
10-20%; usually 1-3 mm larger
Landing in EIA specific consideration
land > 15 mm away from major angulation
CIA seal length
2-3 cm
Generic EVAR limits
1) neck 10-15 mm 2) angle 45-60 degrees (Aorfix 90 degrees) 3) Neck < 32 mm
Percutaneous access benefit and con
1) less groin infection 2) less lymphocele 3) reduce procedure time 4) shorter LOS Con 5) increase cost 6) difficult to convert
Percutaneous access limit in EVAR in terms of size of sheaths
< 24F
Success rate of proglide
18-20F 78-95% 12-16F 95-99%
Relative contraindication to percutaneous access
1) severe groin scarring 2) high femoral bifurcation 3) need multiple introducer changes 4) proximal iliac occlusive disease 5) small iliofemoral artery 6) anterior calcified femorals
Balloon expandable sheaths
SoloPath Onset Medical Groups 11.5-15Fr dilates to 17-24Fr
Iliac conduit steps
1) flank incision retroperitoneal 2) end-to-end on distal CIA 3) tunnel into groin incision 4) end-to-side on CFA or ligate stump at the end
Typical neck angle for EVAR
Cranial 5-15 LAO 10-20
Typical renal orientation
Right anterior Left posterior
Settings for initial aortogram
20 ml/s for 7-15 ml
Failure to cannulate gate strategies
1) arm access 2) up and over 3) AUI FFBY
Minimal iliac landing
2 cm more if larger aneurysmal sac
Completion run setting on injector
15 ml/s for 30 ml keep running for 5s post iliac contrast washout for type 2
Palmaz loading principle
allow proximal balloon inflation first
Treatment for Type 1A endoleak
1) balloon again 2) cuff 3) palmaz 4) endoanchors
Endoanchor principle: neck size and numbers needed
<29 mm needs 4 anchors > 29 mm needs 6 anchors
Endoanchor size and dimention
4.5 mm long 3 mm diameter wires are 0.5 mm diameter
Indication to treat Type II endoleak
Sac growth > 5 mm
IMA embolization prior to EVAR evidence
weak
% of type 2 that were actually occult type 1 or 3
20%
Treatment of Type 2 endoleak
1) embolize via transarterial, translumbar, transcaval 2) laparoscopic IMA clip 3) open ligate of lumbar/IMA 4) conversion to open graft sew
Rate of Failure to treat type 2
20%
Current EVAR stent grafts and their FDA approval time
Current EVAR grafts and their specific sizes and features
