Transcript Endovascular Repair of Aneurysms.

Angela Diamond, MD, FACS, RVT.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Generally a disease of older males:
 Annual incidence of less than 1 in 1000 people younger
than 60 years old
 Peaks at approximately 7 in 1000 people in their mid-60’s
 5 to 6 times more common in men than women.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Risk factors include:
 Male gender
 Positive family history
 Older age
 Smoking
 Coronary Artery Disease
 Peripheral Vascular Disease
 White race
 Hypercholesterolemia.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Definition:
 An aneurysm is defined as a widening or dilatation of a
vessel.
 The infrarenal diameter should be 1.5 times the expected
diameter.
 Normal diameter varies with age, sex and body weight.
 Therefore, no definite diameter; however,
conventionally diagnosed when the infrarenal aorta has
a transverse diameter of at least 30 mm.
Endovascular Repair of Aneurysms
Abdominal Aorta
 The dilatation affects all 3 layers of the aorta and is
usually fusiform, i.e. affecting the whole
circumference.
 Pathogenesis is poorly understood, the development is
clearly associated with alterations in the connective
tissue in the aortic wall.
 The aortic wall contains vascular smooth muscle cells
as well as matrix proteins - elastin and collagen.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Histological features of an aneurysm wall:
 Fragmentation of elastic fibers in the media
 Dilatation of the medial wall
 Then the adventia, which is primarily made up of
collagen, becomes responsible for the strength of the
aorta
 Collagen degradation is the ultimate cause of rupture.
Endovascular Repair of Aneurysms
Abdominal Aorta
 The alterations in collagen and elastin in the aortic
wall is dependent on production of proteases by
medial smooth muscle cells, adventitial fibroblasts
and the cells of the lymphomonocytic infiltrate.
 Matrix Metalloproteinases (MMP’s)
 Tissue Inhibitors of Matrix Metalloproteinases (TIMPs).
Endovascular Repair of Aneurysms
Abdominal Aorta
 Abdominal aortic aneurysms (AAA) may be
asymptomatic for years; however, 30% will go on to
rupture, if left untreated.
 Majority of patients with ruptured aneurysms die
before making it to the hospital or emergency room.
 Those who make it to surgery have a high morbidity
and mortality and only 10%-25% will ultimately survive
until discharge.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Risk of rupture is related to the size of the aneurysm.
 Multiple studies have agreed that the risk of rupture
increases to a point that elective repair is warranted
when the diameter reaches 5.0 to 5.5 cm
 Controversy exists in the management of small
aneurysms.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Diameter of the AAA is not the only isolated factor in
risk of rupture; small aneurysms do rupture and larger
ones remain stable for long periods of time.
 Studies have shown that a larger initial diameter,
COPD, and hypertension have all been independent
predictors of rupture.
 Female gender (women having a 3-fold higher risk of
rupture than men), familial AAAs and smoking have
also been implicated.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Current thinking is rupture depends on diameter:
 AAA < 4 cm – 0% per year, rupture
 AAA 4 to 5 cm – 0.5 to 5.0 % per year, rupture
 AAA 5 to 6 cm – 3 to 15 % per year, rupture
 AAA 6 to 7 cm – 10 to 20 % per year, rupture
 AAA 7 to 8 cm – 20 to 40 % per year, rupture.
Endovascular Repair of Aneurysms
Abdominal Aorta
 History and Physical Exam
 Hypertension, COPD, coronary artery disease, smoking,
family history of AAA.
 Positive physical examination of the supra-umbilical
region with bimanual palpation depends on the size of
the AAA:
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61% for 3.0 to 3.9 cm
69% for 4.0 to 4.9 cm
82% for 5 cm or greater.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Noninvasive Imaging:
 Abdominal x-rays
 Ultrasonography
 Computed Tomography Angiography
 Magnetic Resonance Angiography
 Conventional Angiography.
 US Preventive Services Task Force is now recommending
screening for all men ages 65 to 75, who ever smoked, for
AAA, via an abdominal aortic ultrasound.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Medical Treatment
 Beta blockers, specifically propranolol
 Indomethacin
 Angiotensin II blockers
 Nonsteroidal anti-inflammatory drugs
 Tetracyclines
 HMG-CoA reductase inhibitors (statins)
 Angiotensin-converting enzyme inhibitors.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Indications for Intervention:
 Rupture
 > 5.5 cm
 Rapid expansion in a short period of time, > 0.7cm in 6
months
 Symptomatic aneurysms: patients with pain and tenderness
over their aneurysm
 Complications associated with aortic aneurysms:
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Distal embolization
Thrombosis
Fistulization
Local compression of adjacent organs.
Endovascular Repair of Aneurysm
Abdominal Aorta
 Open Repair:
 1923, Rudolph Matas performed the first successful aortic ligation to
treat aortic aneurysm
 1930, Blakemore and King tried to induce thrombosis of the aneurysm
sac by passing a current through wires that were placed into the
aneurysm sac
 1940’s, cellophane was used in humans to wrap the aorta to induce
periarterial fibrosis, to prevent rupture
 1951, Dubost performed the first successful aneurysm excision and
repair with the use of an arterial homograft to replace an aortic
aneurysm
 1954, Debakey performed an AAA repair using Dacron. In the 1950’s,
aneurysms were excised prior to replacing the aorta with a graft.
 1960’s, Oscar Creech popularized the open endoaneurysmorrhaphy
that we know it today, leaving the back wall of the aneurysm intact and
oversewing the lumbar vessels.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Endovascular Repair (EVAR) for an AAA was first described by
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Parodi et al in 1991.
This technique modeled after the work by Dotter et al was
initially designed for patients too sick to undergo conventional
open aortic repair.
The endograft is a vascular prosthetic graft attached to a stent
and is delivered to the aorta via a transfemoral route. Under
fluoroscopic guidance, the device is placed beneath the renal
arteries and “deployed”- essentially relining the aorta.
Once the endograft is in place the blood travels through the
device and excludes the aneurysm sac, preventing rupture.
The initial endografts were physician made.
Endovascular Repair of Aneurysms
Abdominal Aorta
 3 areas of review are needed before considering the
patient for an EVAR:
 Proximal Neck
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1.5 cm in length, up to 32 mm in diameter
 Distal Landing Zone
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Ectasia and/or aneurysmal
 Access Vessels
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Calcium and tortuosity.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Clinical Trial of EVAR
 Endovascular Aneurysm Repair 1 Trial (EVAR-1)
 Dutch Randomized Endovascular Aneurysm
Management Trial (DREAM)
 Open Versus Endovascular Repair Trial (OPEN)
 United Kingdom EVAR Trial Investigators.
Endovascular Repair of Aneurysms
Abdominal Aorta
 Complications:
 Endoleaks
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I: Inadequate seal of proximal or distal end.
II: Flow from patent lumbar, middle sacral or inferior
mesenteric artery.
III: Fabric disruption or tear. Module disconnection.
IV: Flow from fabric porosity.
Endovascular Repair of Aneurysms
Thoracic Aorta
 The thoracic aorta can be divided into 3 segments:
 The ascending aorta (from the heart to the innominate
artery)
 The aortic arch (from the innominate artery to the left
subclavian artery)
 The descending aorta (from the left subclavian artery to
the level of the diaphragm)
Beyond is the visceral aortic segment, wherein the renal
and the visceral vessels arise.
Endovascular Repair of Aneurysms
Thoracic Aorta
 Aneurysms of the descending thoracic aorta are mostly
degenerative in nature and indistinguishable from
AAA.
 20-30% of aortic aneurysm patients have a first order
relative with the disease.
 Continues to be a debate over whether aneurysmal
degeneration is a sequela of atherosclerosis or a
primary connective tissue weakness, recent studies
suggest overlap.
Endovascular Repair of Aneurysms
Thoracic Aorta
 The second most common etiology of descending
thoracic aortic aneurysms is as the sequela of chronic
aortic dissection.
 Of patients experiencing acute aortic dissection, 25%
to 40% will develop chronic aneurysmal dilatation of
the outer wall of the false lumen, which renders them
susceptible to late aneurysm rupture and death.
 Giant cell arteritis, Marfan’s syndrome.
Endovascular Repair of Aneurysms
Thoracic Aorta
 Expected natural history is progressive enlargement
and eventual rupture, regardless of etiology or
location.
 Women make up half of thoracic aneurysm patients as
opposed to 10%-20% of those with AAA.
 Mean rate of growth for all thoracic aneurysms is 0.1
cm per year.
Endovascular Repair of Aneurysms
Thoracic Aorta
 Natural history observations have led to the
acceptance of 6 cm as the size threshold for
recommendation of surgical intervention for
degenerative descending thoracic aneurysms.
 Or growth rates of >10 mm per year.
 Increasing expansion rate is used an indicator of
heightened rupture risk as is the presence of aortic
tenderness, and, in some cases, consideration is given
to earlier operation.
Endovascular Repair of Aneurysms
Thoracic Aorta
Clinical presentation:
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Chest and/or back pain
New onset of hoarseness
Chronic cough
Hemoptysis
Dyspnea
Dysphagia lusoria
Distal embolization.
Medical treatment consists of beta blockers to keep the systolic
pressure at the low normal range of 105 to 120 mm Hg, and this
often requires additional medications to maintain.
Endovascular Repair of Aneurysms
Thoracic Aorta
 Endoluminal treatment of isolated thoracic aortic
aneurysms with stent grafting was introduced in 1994,
by Dake et al.
 Several anatomic barriers to thoracic stent grafting:
 Proximal and distal seal zones should be at least 2 cm in
length.
 Delivery systems for thoracic endografts are larger than
their abdominal counterparts, with the largest devices
requiring an iliac diameter of 9 mm.
Endovascular Repair of Aneurysms
Thoracic Aorta
 Results:
 PIVITOL trial
 EUROSTAR
 United Kingdom Thoracic Endograft registries.
Endovascular Repair of Aneurysms
Popliteal Artery
 Aneurysm of >2.5 cm
 If left untreated, patients do not present with rupture
but with acute limb ischemia due to occlusion of the
aneurysm with clot.
 Stent placement via common femoral artery
 Continue to need a seal zone 2 cm above and below
the aneurysm, not including the tibial peroneal trunk.
 Plavix and aspirin for the lifetime of the patient due to
a small covered stent in a bendable part of the
extremity.
Endovascular Repair of Aneurysms
Conclusion
 Infrarenal abdominal, descending thoracic and popliteal
artery aneurysms have all been successfully stented with
covered stents. We do more vascular surgery stenting for
aneurysms here at Harrison hospital than any other
hospital in Washington state except for the University of
Washington hospital system.
 An aneurysm that has not been successfully stented
endovascularly is a common femoral artery aneurysm due
to its branching into the superficial femoral and the
profunda arteries.
 Thank you very much for your time today!