Abdominal Aortic Aneurysms Diagnosis and treatment.

Abdominal Aortic Aneurysms

Diagnosis and treatment

AAA defintion

Normal aorta Aorta with an abdominal aneurysm

Varies by age, gender, body surface area

Typically diagnosed if aortic diameter is ≥ 3.0 cm*

*ACC/AHA Guidelines on PAD Circulation 2006;113:e463-465.

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 cm45-54 1.3% 0%

75-84 12.5% 5.2%

ACC/AHA Guidelines on PAD Circulation 2006;113:e463-465.

Risk factors associated with AAA

Older age

Male sex

Family hx

Smoking

Hypertension

Dyslipidemia

Atherosclerotic disease

COPD

ACC/AHA Guidelines on PAD Circulation 2006;113:e463-465.

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

AAA Sequelae

Natural history• gradual and/or sporadic expansion• accumulation of mural thrombus

Complications• rupture• thromboembolic events• compression of adjacent structures

Progression of a AAA

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

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

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 2006;113:e463-465.

AAA: risk of rupture

Simplifed estimates based on various studies

Tan W Abdominal Aortic Aneurysm Rupture www.emedicine.com

0

Risk of rupture for untreated aneurysm within 5 years (%)

10

7060

4050

3020

80

25%35%

75%

Aneurysm size5-5.9cm 6-6.9cm ≥7cm

Rupture outcomes

Mortality rate can be as high as 80%[1]

More than one third of rupture cases die outside the hospital[2]

Ruptured AAA

1. Adam. J Vasc Surg 1999;30:922-8.

2. Thomas. Br J Surg Aug 1988

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 casesQureshi. 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.

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 2006;113:e463-465.

Class IClass IIa

Class IIbClass III

Diagnosis: physical exam

In one study (N=198)• 48% of AAA cases were diagnosed clinically• physical exam missed 38% of cases detected

radiologically

Karkos CD. Eur J Vasc Endovasc Surg 2000;19:299-303.

Sensitivity of physical exam

Lederle. JAMA 1999;281:77-82.

Aneurysm diameter

Sensitivity

3.0-3.9 cm 29%

4.0-4.9 cm 50%

≥ 5.0 cm 76%

Pooled analysis of 15 studies

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 1989;69:713-20.

Ultrasound screening

5

20

8

29

9

27

0

5

10

15

20

25

30

Number

Emergency Ops Rupturedaneurysms

AAA deaths

Screened Control

Lindholdt. BMJ 2005;330:750.

Controlled screening trial of men age 65 to 73 ITT analysis n=6333 screened, n=6306 control

P=0.002P=0.001 P=0.003

ACC/AHA Guidelines AAA repairInfrarenal/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 >5.5-6.0cm

AAA <4.0cm, ultrasound every 2-3 years is reasonable

Intervention not recommended asymptomatic infrarenal/ juxtarenal AAAs <5.0 cm (men) or <4.5 cm (women)

ACC/AHA Guidelines on PAD Circulation 2006;113:e463-465.

Class IClass IIa

Class IIbClass III

Treatment options

Endovascular stent graftingOpen surgery

Open repair: advantages

Established procedure more than 40 years of clinical experience

Excludes aneurysm and prevents sac growth

Proven, long-term results

Open surgical repair (OSR): drawbacks

Significant incision in the abdomen

30–90 minute cross-clamp

Up to 4-hour procedure

1–2 days intensive care7–14 days hospitalization4–6 weeks recovery time

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 2001;33:913-920.

2. Lee. Ann Vasc Surg 2000;14:13-19.

Early OSR vs watchful waiting

Endpoint Relative risk 95% CI

All cause mortality 1.01 0.77-1.32

Aneurysm-related mortality 0.78 0.56-1.10

Combined ADAM and UKSAT trials of early/immediate OSR vs surveillance/delayed OSR for AAA < 5.5 cm

N = 2226

Lederle. Ann Intern Med 2007;146:735-741.

Endovascular aneurysm repair (EVAR)

Benefits• minimally invasive• reduced risk of

perioperative death• faster recovery

Preoperative angiogram Postoperative angiogram

®

AAA repair with stent graft

EVAR

Drawbacks

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

Morphology suitable for endovascular repair

• adequate vascular access

• appropriate aortic neck length and angulation

Endovascular stent grafting

EVAR vs OSR 30-day outcomes

Trial Endpoint EVAR OPEN P

EVAR [1]

N=1082 ≥ 5.5 cm

Mortality 1.7 % 4.7 % 0.009

Secondary interventions

9.8 % 5.8 % 0.02

DREAM [2] N=345

≥ 5.0 cm

Mortality 1.2 % 4.6 % 0.1

Mortality & severe complications

4.7 % 9.8 % 0.1

1. Lancet 2004;364:843-8.

2. N Engl J Med 2004;351:1607-1618.

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 2005;352:2398-405.

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)

N=153

Prinssen. J EndovascTher 2004;11:613-620.

Erectile dysfunction

Erectile function worsened after open repair (p=0.002)

Orgasmic function deteriorated after open repair (p=0.001)

Endovascular repair was not accompanied by decreased erectile or orgasmic function (p=0.057 and p=0.068, 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 (p=0.036)

N=90

Xenos. Ann Vasc Surg 2003;17:530-538.

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

Medicare cohort 4 yr outcomes

Endpoint* EVAR OPEN P

Periop mortality 1.2 % 4.8 % <0.001

AAA rupture 1.8 % 0.5 % <0.001

AAA reintervention 9.0% 1.7% <0.001

Laparotomy-related

Reintervention 4.1% 9.7% <0.001

Hospitalization 8.1% 14.2% <0.001

Schmermerhorn N Engl J Med 2008;358:464-474.

* All 4 yr except perioperative mortality N=22 830 matched patients

Ongoing studies EVAR vs OSR

France• Anévrisme de l’aorte abdominale: chirurgie

versus endoprothèse (ACE)ClinicalTrials.gov identifier: NCT00224718

US• Open versus endovascular repair (OVER) trial

for AAA • ClinicalTrials.gov identifier: NCT00094575