Thoracic(Aneurysms(and( Dissecons - Performables...Complications • Implantation-Procedure Related๏ Neurologic (Stroke, Paraplegia) ๏ Vascular (Access, Dissection) ๏ Ischemic

Thoracic Aneurysms and Dissec2ons

Mark A Farber, MD FACSDirector, Aor2c Disease Center

Vascular Surgery Program DirectorAssociate Professor of Surgery and Radiology

University of North CarolinaChapel Hill, NC 1

Monday, August 6, 12

Disclosures

• Consultant–WL Gore–Cook Medical–Bolton Medical–Aptus

• Speaker–Cook Medical–WL Gore–Bolton

2


Outline• Classifica2on of TAAA and Dissec2ons• Pathogenesis

–Aneurysms–Dissec2ons

• Diagnosis• Management

–Medical–Surgical

•Open• Endovascular

3


Classifica2onModified Crawford

4


Classifica2onDissec2ons

5


EpidemiologyTAAA

• Younger than pts with AAA (65 versus 75)• M:F ra2o 1.7:1• Secondary to dissec2on in 20%• Incidence: 10.4/100,000

–Seems to be increasing

• Synchronous aneurysm risk–20-‐30% have AAA–6-‐13% have asc or arch dz

6


Rupture Risk• 5-‐yr survival for a 6 cm TAAA: 54%• Associa2ons between rupture and either COPD or renal failure

• Size is most important risk factor–Other factors:

•Older age• COPD• Con2nued pain

• Growth Rate 0.1 -‐ 0.4 cm/year• Dissec2on pts rupture at smaller diameters

7


Pathogenesis• Mul2factorial in most cases• Increased MMP ac2vity

–Interac2on between MMP-‐9 and MMP-‐2–Degrada2on of extracellular matrix

• Characterized by medial degenera2on–Fragenta2on of elas2c fibers, loss of SMC

• Marfan’s accelerated medial degera2on

8


E2ology of TAAA

• Degenera2ve -‐ 80%• Dissec2ons -‐ 15-‐20%• Connec2ve 2ssue disorder -‐ 2%• Myco2c• Misc

9


Diagnosis• CXR may show enlargement• Axial/3D imaging study is now gold standard• No current biomarkers for TAAA

10


Medical Therapy• No level A or B evidence for comparisons• Sta2ns -‐ may have inhibitory effect on growth but no direct evidence

• Smoking -‐ cessa2on should be encouraged• BP Control

–ARI -‐ reduces oxida2ve stress and growth–Beta Blockade -‐ reduces dP/dt which slows growth of TAAA related dissec2ons but not TAAA

11


Clinical Presenta2on• Most are asymptoma2c at 2me of diagnosis however 50-‐60% will develop sx prior to rupture–Vague pain–Hoarseness–Tracheal devia2on

• Concomitant aneurysms: 20-‐30%

12


Treatment Op2ons

• Decision for repair is based upon risks of procedure versus rupture–Good risk pa2ents may be treated at 5 cm

• TEVAR IFU–Other suggest 6-‐6.5 cm as threshold–Lower for pa2ents with CT disorders, +FH for rupture or dissec2on, rapid growth

13


Open versus EV Repair• Surgical repiar is associated with significant morbidity and mortality (depends upon volume and presenta2on)–Mortality: 4-‐25%–Morbidity: 20-‐50%–Paraplegia: 4-‐25%

• Endovascular Repair–Outcome impacted by anatomic pa2ent selec2on

• Reduced MAE

–No difference long-‐term all cause ortality 67% vs 68%)

14


TEVAR Results

15


Approved TEVAR Devices

• Gore TAG and cTAG• Cook TX2• Medtronic Talent and Valiant• IFU for all devices is TAAA or PAU

–Not transec2on–Not dissec2on

• Most common complica2on–Immediate: iliac artery injury 18%

16


Device Characteris2cs

17

Device Diameter(mm)

Profile(Fr)

Lengths(mm/section)

Talent 22 - 46 22 - 25 75 - 115

Valiant 22-46 22 - 25 100-200

GorecTAG 21-45

20 (7.6)22 (8.3)24 (9.2)

100, 150, 200

Cook TX2 28 - 3436 - 42

20 ID22 ID 85, 120 - 216

Cook TX2 LP18-‐3234-‐4042-‐46

16 ID18 ID20 ID

120-‐200+

Bolton Relay 22 - 46 22-25 ~100, ~150, ~200, ~250


Device Implant Loca2on

Proximal Sealing Region• Zone 0: 5%• Zone I: 4%• Zone II: 15% (3% BPG)• Zone III: 35%• Zone IV: 30%Distal Sealing Region• Visceral: 9%


Complications

• Implantation- Procedure Related

๏ Neurologic (Stroke, Paraplegia)

๏ Vascular (Access, Dissection)

๏ Ischemic (Branched Vessel Occlusion, Embolic)

๏ Renal Issues (CIN)

- Device Related๏ Deployment Failure

๏ Non-coaxial deployment๏ Conformation

๏ Delivery Failure

• Post-Implantation- Device Failure

๏ Migration

๏ Endoleak

๏ Collapse๏ Fatigue (Metal, Fabric)

๏ Perforation๏ Sac enlargement

- Graft Infection- Disease Related

๏ Disease progression


Stroke• Stroke during TEVAR: 4-10%

• Mechanisms: Ischemic vs. Embolic

• Associated with number of manipulations

• More common when device extends into arch


Vertebral Anatomy

• L vertebral artery dominant in 60-65% (A)

• PICA syndrome

- 1-2% complete R vertebral disjunction (B)

- 3-4% atretic R vertebral artery (C)

A

CB

Prevention: Cerebrovascular Imaging


Prophylactic Left SCA Revascularization

• Absolute Indications (pre-operative)- Dominant left vertebral artery w/

Zone 2 coverage๏ 60% left vertebral artery dominant๏ 2% “PICA” syndrome

- LIMA à LAD CABG

- Left handed patient

- Left arm AV Fistula

- Aberrant arch origin of left vertebral

• Relative Indications

- Coverage length > 20 cm

- Prior AAA repair

- Occlusive dz


Spinal Cord Ischemia (SCI)• Up to 10% incidence after TEVAR

- Gore TAG Pivotal Trial (JVS 2005;14:1-9)

๏ 3% vs. 14% surgical controls

- Cook TX2๏ 1.9% vs 5.7% open arm

- Medtronic Talent๏ 1.5%

• Mechanism of SCI unclear- Temporary or permanent- Immediate or delayed

• Published literature- No established protocol for prospective analysis- Mixed pathologies (dissections, aneurysms,

transections, elective, emergent, etc.)


Risk Factors for TEVAR• Length of aortic coverage

• Prior abdominal aortic surgery

• Pelvic occlusive disease (internal iliac occlusion) or iliac artery injury

- Conduit use

• L subclavian artery coverage?

• Peri-operative hypotension

• Renal failure


Fractional Aortic Coverage

Feezor et al. Extent of aortic coverage and incidence of spinal cord ischemia after thoracic endovascular aneurysm repair. Ann Thorac Surg (2008) vol. 86 (6) pp. 1809-14; discussion 1814.


CT Analysis

• Multivariate logistic regression

- 22 variables

- Absolute length of total aortic coverage AND length of distal uncovered aorta associated with SCI

๏ X: 30% ⇑ risk for every 2-cm additional coverage (p=0.0006)

๏ Y: 40% ⇓ risk for every 2-cm uncovered distal thoracic aorta (p=0.0006)

X

Y


Spinal Drainage• Spinal drain management

- Immediate 50 cc drainage

- Mean BP > 90

- >20-cm coverage OR distal coverage <5-cm prox to celiac artery

- Limit drainage <15-ml/hr or <350-ml/d๏ Drain for > 12 mm๏ Overdrainage è risk of subdural hematoma

- Prophylactic drainage๏ 24 hr drainage è 24 hr clamp è removal

- Therapeutic drainage๏ 72 hr drainage è reduce BP è 24 hr clamp

è removal

- Drainage maximum of 5 days*


Vascular Access• Primary access (22-25 F)

- Critically important

- Access complication à single most preventable adverse event (18-20%)

- Femoral: open vs. percutaneous

- Iliac conduit (15-20%)

- Aortic conduit (rare)

- May be associated with increased paraplegia risk

18%

82%

Open Exposure

Iliac Conduit


Iliac Conduit

Conduit of Choice: 10 m DacronMonday, August 6, 12


Iatrogenic Retrograde Dissec2on


Branch Vessel Occlusion

* Courtesy Anthony Lee


(Arch) ConformationRadius of curvature


Post-Operative Complications


Bare Stent Perforations

Completion 3 month1 month

From Bolton Relay Clinical Trial


Secondary Repair


Endograft Infection


Infolding• Incorrect Oversizing

• Non-tapered (straight) designs w/ discordant proximal-distal diameters

è Endoleak

è Aortic occlusion (coarctation)

Sensitivity: Device specific


Device Collapse

• Oversizing• Small radius of

curvature• Increased radial force• Management

- Palmaz stent- Elective conversion- Second device


Collapse Incidence• Implants: > 30,000

• Reported Cases: 134 (0.4%)

- Mostly traumatic injuries

• Root Cause Analysis:

- Excessive oversizing (99%)

- Increases flow velocity with small aortic diameters (young patients)

- Lack of device apposition


11

2

5

423

5

43

5

43

6

1

2

PreD/C 24M12M

Component Separation

7

6


Stent/Connecting Bar Fractures


E2ologyDissec2ons

• Incidence: 3/100,000 person yrs• Associated factors: HTN, older age, structural abnormali2es, bicuspid valvular disease (7-‐14%), cocaine inges2on (37%)–Catecholamine: htn, vc, and inc CO

• Male:Female 4:1• Type A: Type B 60:40• More oien in winter and in the morning hours

43


Malperfusion

• Dynamic Obstruc2on• Sta2c Obstruc2on

• Occurs in 31% of pa2ents and associated with increased mortality

44


Diagnosis• CT scan is the mainstay of diagnosis• TEE: helps in determining proximal extent and entry tears

• D Dimer: –typically elevated–if nega2ve then likelihood of AD rare

45


Natural History• Aneurysmal degenera2on occurs in approximately 50% of pa2ents at 5 years–Degenera2on depends upon

• False lumen thrombosis• Size at 3 months predicts outcome

–<4.5 30%–>4,5 cm 70%

• Survival: 75-‐80% @ 3 years

46


Treatment• An2-‐Impulse Therapy:

–Beta blockade and nipride to reduce dP/dt–Labetelol (or esmolol) prior to nipride

• Interven2on is generally reserved for symptoms–Malperfusion of end organs (renal, mesenteric, LE, spinal cord)

–Rupture–Impending rupture (rapid expansion)–Persistent pain and HTN

47


Goals of Interven2on

• Correct Malperfusion–Surgical bypass (i.e. fem-‐fem BPG)–Open fenestra2on equalizes pressures, removes septum)

–Open repair–TEVAR: Repressurize TL, decompress FL

•May require branched vessel sten2ng for sta2c issues

–Perc Fenestra2on: Equalized pressures48


IMH and PAU

• IMH: collec2on of blood in the media–No direct communica2on to lumen

• PAU: defect in the elas2c lamina leading to poten2al rupture

49


Penetra2ng Ulcer

50


IMH

• Intramural thickening without communica2on with lumen

• May rupture or regress• May evolve to dissec2on or rupture and may be sudden or heralded by an AAS

• Usually changes over first thirty days• Can be difficult to dis2nguish from acute dissec2on

51


E2ology and Diagnosis• Abrupt onset of severe chest/back pain• Typically in older pa2ents with HTN and generalized atherosclerosis–May have some rela2on to ruptured vasa vasorum–Prior PAU

• Axial imaging is typically require for dx

52


IMH, PAU and Dissec2ons

• Tradi2onal thinking• Differences in clinical presenta2on exist

–Pa2ents with PAU• Older than those with AD• Exhibit athersclero2c disease in other areas of the aorta• Cratered in2ma

–Symptoma2c vs Asymptoma2c–Ascending vs Descending

Spectrum of Disease

IMH Dissec2onPAU

Sundt Ann Thor Surg 2007; 83: S835-‐41. 53


Alterna2ve View

Sundt Ann Thor Surg 2007; 83: S835-‐41. 54


Treatment

• Asymptoma2c pa2ents may show resolu2on in 50-‐80%–IMH: thickness greater than 1 cm -‐-‐> 9x increase in progression

–Treatment is medical therapy in most•Need frequent re-‐imaging

• Symptoma2c paitents associated with a 33% rupture risk–Most likely treatment is SG repair

55


IMH Resolved

56

Pre-‐Opera2ve 1 month Post-‐Op


Documents

Thoracic(Aneurysms(and( Dissecons - Performables...Complications • Implantation-Procedure Related๏ Neurologic (Stroke, Paraplegia) ๏ Vascular (Access, Dissection) ๏ Ischemic