Abdominal Aortic Aneurysms Diagnosis and treatment

1
Abdominal Aortic AneurysmsDiagnosis and treatment
2
AAA defintion

• Varies by age, gender, body surface area
• Typically diagnosed if aortic diameter is 3.0
  cm

ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
3
Prevalence of AAA

• In the US, AAA causes almost 14 000 deaths each
  year and accounts for 63 000 hospital discharges

Age (years) Men Women
2.9 - 4.9 cm 45-54 1.3 0
2.9 - 4.9 cm 75-84 12.5 5.2
ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
4
Risk factors associated with AAA

• Older age
• Male sex
• Family hx
• Smoking
• Hypertension
• Dyslipidemia
• Atherosclerotic disease
• COPD

ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
5
Types of AAA

• Morphological classification
• fusiform aneurysms
• saccular aneurysms
• dissecting aneurysms
• pseudo-aneurysms
• Segments involved
• thoracic
• thoraco-abdominal
• abdominal
• main branches of the aorta
• iliac arteries

6
AAA Sequelae

• Natural history
• gradual and/or sporadic expansion
• accumulation of mural thrombus
• Complications
• rupture
• thromboembolic events
• compression of adjacent structures

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Progression of a AAA

• Pathological changes cause the aorta wall to
• become thinner
• bulge
• tear
• rupture

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Growth rate of AAA

Initial size (cm) Mean growth rate (cm/yr) 95 CI
3.0- 3.9 0.39 0.20-0.57
4.0-4.9 0.36 0.21-0.50
5.0-5.9 0.43 0.27-0.60
6.0-6.9 0.64 0.16-1.10
Tan W Abdominal Aortic Aneurysm Rupture
www.emedicine.com
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Symptoms of AAA rupture

• Abdominal/back pain
• Pulsatile abdominal mass
• Hypotension
• Clinical triad occurs in only about one-third of
  cases.

ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
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AAA risk of rupture
Risk of rupture for untreated aneurysm within 5
years ()
75
80
70
60
50
40
35
25
30
20
10
0
5-5.9cm
6-6.9cm
7cm
Aneurysm size
Simplifed estimates based on various studies
Tan W Abdominal Aortic Aneurysm Rupture
www.emedicine.com
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Rupture outcomes

• Mortality rate can be as high as 801
• More than one third of rupture cases die outside
  the hospital2

1. Adam. J Vasc Surg 199930922-8.
2. Thomas. Br J Surg Aug 1988

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Operative mortality

• 35-70 for ruptured aneurysm
• Pae. J Am Surg 2007 Qureshi. Ann Vasc Surg 2007
  Greco. J Vasc Surg 2006 Pepplenbosch. J Vasc
  Surg 2006 Visser. Eur J Vasc Endovasc Surg 2005
  Brown. Br J Surg 2002 Heller. J Vasc Surg 2000
  Adam. J Vasc Surg 1999 Johansen. J Vasc Surg
  1991 Ouriel. J Vasc Surg 1990.
• 1.0-8.0 for elective AAA cases
• Qureshi. Ann Vasc Surg 2007 Cowan. Ann NY Acad
  Sci 2006 Heller. J Vasc Surg 2000 Bradbury. Br
  J Surg 1998 Blankensteijn. Br J Surg 1998.

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ACC/AHA screening high-risk

• Men 60 yrs who are siblings or offspring of
  AAA patients
• Men 65-75 yrs who have ever smoked
• Physical exam and ultrasound

ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
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Diagnosis physical exam

• In one study (N198)
• 48 of AAA cases were diagnosed clinically
• physical exam missed 38 of cases detected
  radiologically

Karkos CD. Eur J Vasc Endovasc Surg
200019299-303.
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Sensitivity of physical exam
Aneurysm diameter Sensitivity
3.0-3.9 cm 29
4.0-4.9 cm 50
5.0 cm 76
Pooled analysis of 15 studies
Lederle. JAMA 199928177-82.
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Sensitivity of ultrasound

• Ranges from 82 to 99
• Approx 100 in cases with a pulsatile mass
• In a small proportion of patients, visualization
  of the aorta inadequate due to obesity, bowel
  gas, or periaortic disease

Quill. Surg Clin North Am 198969713-20.
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Ultrasound screening
P0.003
P0.001
P0.002
Controlled screening trial of men age 65 to 73
ITT analysis n6333 screened, n6306 control
Lindholdt. BMJ 2005330750.
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ACC/AHA Guidelines AAA repair

• Infrarenal/juxtarenal AAA 5.5 cm should undergo
  repair 4.0-5.4 cm, ultrasound/CT scans every
  6-12 mo
• Repair can be beneficial for
  infrarenal/juxtarenal AAAs 5.0-6.0 cm
• Repair probably indicated for suprarenal/type
  IV thoracoabdominal AA gt5.5-6.0cm
• AAA lt4.0cm, ultrasound every 2-3 years is
  reasonable
• Intervention not recommended asymptomatic
  infrarenal/ juxtarenal AAAs lt5.0 cm (men) or
  lt4.5 cm (women)

ACC/AHA Guidelines on PAD Circulation
2006113e463-465.
19
Treatment options
Endovascular stent grafting

• Open surgery

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Open repair advantages

• Established procedure more than 40 years of
  clinical experience
• Excludes aneurysm and prevents sac growth
• Proven, long-term results

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Open surgical repair (OSR) drawbacks

• Significant incision in the abdomen
• 3090 minute cross-clamp
• Up to 4-hour procedure
• 12 days intensive care714 days
  hospitalization46 weeks recovery time

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Contraindications to OSR

• High anesthesia risk
• Severely obese
• Significant cardiac co-morbidities
• Previous abdominal surgery/hostile abdomen
• Difficult recovery for patient
• risks functional impairment 1
• risk of erectile dysfunction 2

1. Williamson. J Vasc Surg 200133913-920. 2.
Lee. Ann Vasc Surg 20001413-19.
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Early OSR vs watchful waiting
Combined ADAM and UKSAT trials of early/immediate
OSR vs surveillance/delayed OSR for AAA lt 5.5
cm N 2226
Endpoint Relative risk 95 CI
All cause mortality 1.01 0.77-1.32
Aneurysm-related mortality 0.78 0.56-1.10
Lederle. Ann Intern Med 2007146735-741.
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Endovascular aneurysm repair (EVAR)

• Benefits
• minimally invasive
• reduced risk of perioperative death
• faster recovery

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AAA repair with stent graft

Postoperative angiogram
Preoperative angiogram
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EVAR

• Drawbacks
• Complications and re-interventions
• intrasac endoleaks
• stent graft migration
• modular dislocation

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Endovascular stent grafting

• Morphology suitable for endovascular repair
• adequate vascular access
• appropriate aortic neck length and angulation

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EVAR vs OSR 30-day outcomes
Trial Endpoint EVAR OPEN P
EVAR 1N1082 5.5 cm Mortality 1.7 4.7 0.009
EVAR 1N1082 5.5 cm Secondary interventions 9.8 5.8 0.02
DREAM 2 N345 5.0 cm Mortality 1.2 4.6 0.1
DREAM 2 N345 5.0 cm Mortality severe complications 4.7 9.8 0.1
1. Lancet 2004364843-8.2. N Engl J Med
20043511607-1618.
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EVAR vs OSR 2-year outcomesDREAM
Endpoint EVAR OPEN P
Survival 89.7 89.6 0.86
Survival free of moderate-severe complications 65.6 65.9 0.88
Aneurysm-related death 2.1 5.7 0.05
N Engl J Med 20053522398-405.
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DREAM sexual dysfunction

• Both EVAR and open repair have a negative impact
  on sexual function in the early postoperative
  period.
• After EVAR, recovery to preoperative levels is
  faster than after open repair.
• At 3 months, sexual dysfunction levels are
  similar in both groups.
• Measured 5 aspects (interest, pleasure,
  engagement, orgasm, erection)
• N153

Prinssen. J EndovascTher 200411613-620.
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Erectile dysfunction

• Erectile function worsened after open repair
  (p0.002)
• Orgasmic function deteriorated after open repair
  (p0.001)
• Endovascular repair was not accompanied by
  decreased erectile or orgasmic function (p0.057
  and p0.068, respectively)
• Impairment not associated with age, diabetes, or
  number of patent hypogastric arteries after
  repair
• Significant association between impaired erectile
  function and open aneurysm repair (p0.036)
• N90

Xenos. Ann Vasc Surg 200317530-538.
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Agency for Healthcare Research Quality review
of EVAR vs open surgical repair

• Lower perioperative morbidity and mortality
• Persistent reduction in AAA-defined mortality to
  4 years
• No improvement in long-term overall survival or
  health status
• For AAA 5.5 cm

AHRQ Publication No. 06-E017 August 2006
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Medicare cohort 4 yr outcomes
Endpoint EVAR OPEN P
Periop mortality 1.2 4.8 lt0.001
AAA rupture 1.8 0.5 lt0.001
AAA reintervention 9.0 1.7 lt0.001
Laparotomy-related Laparotomy-related
Reintervention 4.1 9.7 lt0.001
Hospitalization 8.1 14.2 lt0.001
All 4 yr except perioperative mortality
N22 830 matched patients
Schmermerhorn N Engl J Med 2008358464-474.
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Ongoing studies EVAR vs OSR

• France
• Anévrisme de laorte abdominale chirurgie versus
  endoprothèse (ACE)ClinicalTrials.gov identifier
  NCT00224718
• US
• Open versus endovascular repair (OVER) trial for
  AAA
• ClinicalTrials.gov identifier NCT00094575