Quiz 7 Endovascular Aortic Repair Flashcards
What does TEVAR and EVAAR mean?
TEVAR - Thoracic Endovascular Aortic Repair
EVAAR - Endovascular abdominal aortic repair
What does the deployment of a graft require as far as a landing area for the aneurysm?
Requires landing zone of at least 1cm on both sides of the aneurysm.
**Book states proximal landing zone of 15mm and diameter no greater than the diameter of the largest available EV graft.
What was the problem with early tube grafts?
High failure rate due to under estimation of atheromatous disease in the aorto-iliac segments and distal aorta
What was the problem with Aorto-uni-illiac stent grafts?
caused occlusion of the contralateral iliac - which necessitated a fem-fem bypass
What is an advantage to the Modular Bifurcated Stent Graft?
Consists of 2 or 3 components - allows normal aorto-iliac anatomy to be preserved
What is a challenging problem with the Fenestrated stents?
Challenge to line up the holes with arterial openings.
To accomplish an EVAR, what is the determining factor on whether or not you can do this procedure?
This procedure is highly dependent on good access.
What are Branched Stent Grafts good for?
allows for preservation of the origins of vital arteries
Why would a retroperitoneal approach be utilized for Endo Grafting?
In cases where femoral vessels are too small or heavily calcified
What is the common site for retroperitoneal approach?
Distal Aorta or proximal iliac - a dacron graft/conduit will be sewn there
What is a hybrid approach to EVAR and when would that be ideal?
Combines both open surgical and endovascular stenting.
Ideal for cases where stenting would occlude major luminal branches.
If a person needs a TEVAR of the Left Subcalvian artery, you would know that they would also need ________-_______ bypass.
subclavian-carotid bypass before they have a TEVAR.
This is an example of a Hybrid procedure.
When doing a staged Elephant Trunk Procedure, What does Stage I consist of?
Total aortic arch replacement - open procedure
When doing a staged Elephant Trunk Procedure, what does Stage II consist of?
Endovascular repair - using the elephant trunk as the proximal landing zone
When doing a staged Elephant Trunk Procedure, is the pt circulatory system normothermic or hypothermic?
Requires Deep hypothermic circulatory arrest
Is Aortic Visceral Debranching an open, EVAR or hybrid procedure?
Hybrid - If aneurysm involves major visceral branches such as celiac, SMA, inferior messenteric vessels or renals - open revascularization of these vessels is undertaken simultaneously or immediately prior to Endo Stenting
What are your indications for EVAR?
- Elective repair for AAA > 5 cm or growing > 1cm/yr
- Elective repair for TAA > 5.5cm or growing > 3cm/yr
- Symptomatic aneurysms - hoarseness/cough for stimulation of RLN
- Significant Co-morbidities due to increased risk of open procedure
- Traumatic Aortic injuries
- Stanford Type B dissections: Involve aorta distal to the origin of the L Subclavian artery
What is the Stanford Classification system for aneurysm?
Easy way to classify an aneurysm.
- Class A - Involve the ascending aorta and are urgent or emergent cases
- Class B - aorta distal to subclavian arteries
What are the eligibility requirements, as far as aneurysm neck (proximal landing zone) size for grafting?
Length > 15mm
Diameter < 30mm
Angulation < 60 degrees long axis
Thrombus < 2mm layer of mural thrombus
Should the Iliac Arteries need to be free of aneurysm in order to have EVAR?
yes, and they should also be free of occlusive disease. The same goes for whatever arteries will be used for access.
Can an EVAR be done as a MAC case?
Yes but the pt must be able to lay supine for 1-2 hrs
What are some benefits to using Central Neuraxial Blockade for EVAR?
No need for TEE
No need for MEP or SSEP
No need for measures to achieve a motionless field during stent deployment
When would a General anesthetic be the better choice for EVAR?
- Complicated EVAR (fenestrated or branched)
- need for iliac access
- planned use of TEE
- planned hemodynamic manipulations to create a motionless field
- Planned SSEP and/or MEP monitoring
- Hx of difficult airway
What are the goals to anesthetic management of EVAR?
- Maintain hemodynamic stability
- Avoid hypertension and tachycardia
- maintain intravascular volume and early identification/management of bleeding
What factors increase the risk of Acute Kidney Injury during EVAR?
- hypoperfusion
- Stent graft material covering the renal vessels
- emboli to the renal arteries
- Contrast induced nephropathy
How can you avoid Acute Kidney injury during EVAR?
- perioperative euvolemia
- maintain CO and BP
- limit contrast dye exposure
- use iso-osmolar non-ionic contrast dye
- may use pharmacologic strategies in pts with baseline kidney disease (N-acetylcysteine, NaHCO3, Statin drugs)
If during an EVAR, the pt experiences significant or severe hypotension, what is likely the cause?
rupture or bleeding from a vessel
What are the factors involved with Spinal Cord Perfusion Pressure?
SCPP = MAP - CSF pressure
To increase SCPP you would increase the pt’s MAP or decrease their CSF.
What is the artery of Adamkiewicz? Where does it feed from?
Anterior spinal artery - largest is the artery of Adamkiewicz arises from the aorta at T9 - T-12 but can come from as high as T5 to as low as L5
When will someone undergoing EVAR or TEVAR likely have SSEP and MEP monitoring?
When there is a high risk for post-op paraplegia
- allows for ID of ischemic changes immediately and allows for rapid intervention (ie increase MAP or decrease CSF)
When would TEE be used during EVAR?
- To help diagnose and confirm aortic pathology
- ID guidewire, sheath, and endograft location
- detect endoleaks
- cardiac assessment
If someone has already had a previous AAA repair, what would be a concern?
May have already compromised collateral circulation to the spinal cord - may have already sacrificed the IMA or median sacral artery
If your pt develops paraplegia following TEVAR, what should be done?
- Elevate MAP > 80 mmHg
- CSF drain
- repeat neuro exams for evidence of reversal of paraplegia
- Avoid abrupt cessation of CSF drainage
After deployement of an endograft, blood flow should be _____________ through the aorta. During TEVAR the surgeon will need a _________ _______ since the graft will be near major vessels. Migration of a thoracic graft would be ____________.
reduced
Motionless field
Catastrophic
What are some early complications following EVAR?
- Ileofemoral lacerations,
- AKI,
- pelvic and LE ischemia,
- MI,
- paraplegia,
- Stroke
What is post-implantation syndrome?
- Fever,
- leukocytosis,
- elevation of inflammatory mediators (CRP, IL 6, TNF, etc)
What are some late complications following EVAR?
- Device migration,
- endoleaks with aneurysm rupture, -endograft infection,
- long term effects of radiation exposure.
What is an endoleak type I?
Involves the proximal or distal seal zone. May require further ballooning or placement of another graft
What is an endoleak type II?
due to retrograde flow from the intercostals
What is an endoleak type III?
occurs with inadequate overlap and seal between modular componenets
What is an endoleak type IV?
occurs due to porosity of graft (rare in modern grafts)
What is an endoleak type V?
endotension - continued sac extension with no identifiable source
If a crossclamp needs to be performed, what is the most amount of time it can be clamped without the likelihood of paraplegia?
15 minutes
What are some indications for placing a CSF drain for EVAR?
Involvement of T9-T12 (artery of Adamkiewicz)
involvement of arch vessels (origin of ant spine artery)
Previous TAA or AAA
Symptomatic spinal ischemia
After EVAR, you may anticipate hypovolemia and lactic acidosis secondary to…?
- Reperfusion of lower extremities
- visceral ischemia during branched stent graft introduction
- reperfusion syndrome following EVAR of Type B dissection
What are some cardiogenic considerations during EVAR?
- perioperative MI
- guide wire manipulation near aortic arch (baroreceptors) –> arrhythmias
- cardiac tamponade from hemoparicardium from over advancement of guidewire.
