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