Surgical Considerations of TEVAR
University of Alberta,June 14th, 2013
Jehangir AppooLibin Cardiovascular Institute
University of Calgary,
Today:
Lesions/Pathology amenable to TEVAR On labelOff label
Future Directions
Controversies in TEVAR Open vs. EndoManagement of LSCVa.
On label indications: descending thoracic aortic aneurysm
acute, complicated type B dissection
traumatic aortic disruption
In Theory:
In Reality:
DTA: decreased mortality 2% vs. 11%decreased cord ischemia 3% vs. 14%similar CVA riskdecreased ICU, hospital LOS
increased vascular cxsincreased re-interventions
Indications for DTA surgery: ?
Indications changing? Evolving? Rightly or wrongly?
Elefteriades et al. , Yale database
On label Indications
1. DTA
2. Blunt Traumatic Aortic Injury
274 pts open repair, 50 Trauma centres Mortality 31% Paraplegia 8.7%
Fabian et al. J Trauma 2007
18 y.o female in motorcycle accident
On label Indications
1. DTA
2. Blunt Traumatic Aortic Injury
3. Acute, complicated type B dissection
44y.o female: chest pain, hypotension, Hgb 65
Fattori R et al. J Am Coll Cardiol Intv 2008;1:395-402
Hospital survival with acute type B Dissection is poor……even worse if open surgery is required
In Hospital Mortality:
Medical Rx-10%
TEVAR -10%
Open surgery-34%
Other indications aortic coarctationIMHPAUarch aneurysmsascending aortic aneurysms/pseudoaneurysmsaortomegalytype A dissectionsmycotic aneurysms
On label indications: descending thoracic aortic aneurysmacute, complicated type B dissectiontraumatic aortic disruption
2007
2013
Off Label Indications often involve encroachment of arch
and into ascending aorta
Distal Arch Aneurysms
Isolated Ascending Aortic Pseudoaneurysm
Why Zone 0 TEVAR?
Complex Patients
Diffuse aortic disease
Generally need 2 stage procedures with total arch replacement and elephant trunk
Often redo setting
“
Surgeon Year ET1 Mortality
ET2 Mortality
Interval Mortality
Rx Mortality
Svensson 2004 2% 8.5% 14% 18%
Safi 2007 6.3% 9.6% 10% 13.3%
Lemaire/Coselli 2006 12% 4% 25% 36%
Kouchoukos 2007 7.2% -- -- 7.2%
Grieppe 2008 6% 7% 12% 24.5%
Etz, Grieppe et al. – Eur J. CT Surg 2008
Even in centres of experience, operative mortality with 2 stage elephant trunk technique is high
On CPB
Axillary Cannulation
28-30 degrees Celcius
Cross Clamp
Surgical Principles of our Type II Hybrid Arch Technique
28 mm Tube Graft
Left Common Carotid and Left
Subclavian Branches
Brachiocephalic Trunk Branch
Endovascular System Delivery Branch
Hybrid Arch sternotomyascending aortic replacementarch debranchment & TEVARRx combination ascending, arch, and desc pathology
Bavaria et al. J Thorac Cardiovasc Surg 2013; 145:S85-90
2010 – 11 yrs post TypeA 2012 – 2 yrs post Hybrid Arch
Early endoleak 1/15
Graft buckling 1/15
Late endoleak 0/15
Graft migration 0/15
Graft fracture 0/15
Retrograde Type A Dissection 0/15
Calgary Zone 0 Follow up at up to 47 months8176 days of cumulative radiological follow up
CCC 2012
Primary Intimal Tear in Mid or Distal Arch
Arch Aneurysm
Visceral/Renal/Extremity Malperfusion
Radiologic risk factors for future aneurysm formation
Acute Type A Aortic Dissection
Positive Lessons from Hybrid Arch Experience
stent graft can navigate angulation of arch
stent graft appears stable in high force area of ascending aorta
diffuse aortic pathology can be treated in one stage without prolonged circulatory arrest strategies
endovascular technology can be applied to chronic type B dissections
...remains a highly invasive operation involving sternotomy, multiple anastomosis, bleeding...
Branched arch grafts
Fenestrated grafts
Insitu graft fenestration
Chimney grafts
Flow modulating grafts
Future likely involves “closed chest total arch repair”
Closed Chest Total Arch: 1. Cook Branched Arch
Fenestrations for arch vessel stents
L carotid subclavian bypass
40 cases world wide
Custom made
Need landing zone in asc aorta
64 y.o maleType A repair 2009
Complicated course
Aorta growing at rate of 1cm/year
Arch dissectedLarge residual primary
intimal tear in archTrue lumen effaced
2013
Closed Chest Total Arch 2. Modular branch graft
Off the shelf device
First in man: 2013/2014
Closed Chest Arch 3. Chimney Technique
Off the shelf conventional devices
Concern with gutter endoleaks & branch compression
Main indication: emergencies when customized devices unavailable but being used electively in parts of world
Closed Chest Total Arch 4. Najuta graft
Precurved fenestrated arch graft in various configurations off the shelf
Used in over 300 aneurysm cases in Japan
Concern re: risk of stroke
Closed chest total arch 5. Flow Modulating devices
Paradigm change:Not about “aneurysm exclusion”
Scaffold to allow thrombus deposition, flow pattern modulation while maintaing side branch patency
Laminar vs. turbulent flow
Closed Chest Total Arch Flow Modulating devices
Global registry243 pts treatedthoracoabdominal,archacute type B
1 yr f/u of first 55 pts:no aneurysm rupture
All 202 side branches patent
J Endovasc Ther 2013;20:366-377
* aneurysm rupture reported by others
Controversies Lots
Open surgery vs. TEVAR risk stratification vs.quality of life
Mgmt of Left Subclavian artery
CT disordersUse in dissections, chronic dissections – does it work? Significance of endoleaksIndications/Benefit – indolent but catastrophic diseasePalliative therapy mycotic aneurysm
Cancer sxBranch vs. fenestrated….vs. flow modulatingUse of CSF drain
TEVAR vs. Open Surgery
Advantagesless Invasivecosmeticquicker recoverydecrease periop mortdecreased SCIsingle stagefaster – for emerg cases
Disadvantages? durability – so far …goodendoleaksre-interventionfollow up
similar concerns with PCI 25 yrs ago??
TEVAR vs. Open Surgery
TEVAR vs. Open Surgery
Costsdevice costs are high
may come downsurgical grafts not without cost
ICU/hospital costs are less
survival is increased …. Increases costs to system…
cost of follow up imaging
re-intervention costs
TEVAR in young patient has different considerations
Size of “normal” aorta
“growth” of aorta over time/decades
Pros/Cons of Open Surgery
Follow Up
Future options
37 y.o female
26mm x 10cm cTAG & 26-21 x10cm cTAG
Discharged home 3 days post op
Back at work on 7th post op day
No chest scar
1 year f/u – aneurysm sac shrinking in size
Management of left subclavian artery
Can be sacrificed in an emergency in most cases
Elective revasc may decrease stroke balance vs. risk of procedure
likely decreases SCI complete thoracic coveragecompromised internal iliacs
Management of left subclavian artery
Mandatory revascularizationdominant left vertebral arterypatent LITA graft
Strongly suggested revascularization dialysis fistuladominant left arm
Management of left subclavian artery
Mandatory revascularizationdominant left vertebral arterypatent LITA graft
Strongly suggested revascularization dialysis fistuladominant left arm
Management of left subclavian artery
Carotid perfusion for branched/fenestrated grafts
Ax-Ax-L carotid bypass
sometimes simpler than having 3 separate branches
6.5cm aortic root
4+ AI
8cm LVEDD with Severe LV Dysfunction
NYHA Class IV CHF
6cm Descending Thoracic Aortic Aneurysm
59 y.o male
6cm Descending Thoracic Aortic Aneurysm
Neck at Left Carotid allows Zone 2 Landing
Issues with carotid-subclavian at same time as proximal root operation in ill patient with 4+
aortic insufficiency
59 y.o male
Staged approached:
Mechanical Composite Root & Aorto-Left Axillary bypass with L Axillary inflow
TEVAR post op with cTAG
?
Obliteration of false lumen in arch & prox descending aorta
Pigtail catheter in true lumen
What happens to the stent graft in the angulated arch over time?
At 4 years:
Current genereation of grafts appear stable in
ascending aorta
Accommodates sharp curves & forces of
ascending aorta and arch
What happens to the stent graft in the angulated arch over time?
The Evolution of Endovascular
≠
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney/Snorkel technique• Sandwich technique
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney/Snorkel technique• Sandwich technqiue
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney/Snorkel technique• Sandwich technique
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney/Snorkel technique• Sandwich technique
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney/Snorkel technique• Sandwich technique
The Evolution of Endovascular
• Stentgrafts• Many technical innovations and improvements
since these pioneer series to address challenging anatomy inherent with thoraco-abdominal aneurysmal disease
• Fenestrated• Custom / pre-fabricated• In-situ
• Branched grafts• Chimney technique• Sandwich technique
The Evolution of Endovascular
• While these novel ‘hybrid’ endovascular approaches do show promise, there are significant limitations• High cost and lag time (custom fabricated devices)
• Branch thrombosis1
• Need for high volume centers of excellence2
• Similar spinal cord and visceral (renal failure) complication rates compared with surgical techniques2
1. Fenestrated Endovascular Grafting : The French Multicenter Experience. Eur J Endovasc Surg 2010;39:537-442. Branched Endografts for Thoracoabdominal Aneurysms. J Thorac Cardiovasc Surg 2010;140:S171-8
The Evolution of Endovascular
Minimally invasive
In Theory:
In Reality:
Understanding of Zone 0 physiology & biomechanics will lead to improvements in technology will tackle problems of:
conformabilityaccesslanding zone issuebranch issues
This will allow more patients to have “safe, high quality treatment”
Multilayer Flow Modulating Stents
• Global Independent MFM Registry1
– 172 implanted world-wide
– Report on 1st 26 cases from 7 countries • Crawford TAAA (11 type II, 9 type III, 6 type IV)
• 16/26 redo (prior TEVAR)
• 3/26 redo (prior juxtarenal EVAR)
• 2/26 rupture
• 5/26 elective
1. J Vasc Endovasc Surg 2012;19:1-14
Multilayer Flow Modulating Stents
• Global Independent MFM Registry– No aneurysm related death (6mo)
– Visceral branch patency
– Reintervention 2/26 due to stent foreshortening
– Maximal sac diameter and volume• 0-3mo 10%/6% increase, stabilized 3-6mo, reduction
>6mo
1. J Vasc Endovasc Surg 2012;19:1-14
Multilayer Flow Modulating Stents
• Global Independent MFM Registry– FEA
• Improved laminar flow
• Transfer of shear stress from aortic wall to stent
• 55% reduction in aneurysm wall stress
1. J Vasc Endovasc Surg 2012;19:1-14