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Screening Guidelines and Treatment Options for Abdominal Aortic Aneurysms

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Screening Guidelines and Treatment Options for Abdominal Aortic Aneurysms Powered By Docstoc
					                                         Harvard
   Beth Israel Deaconess                 Medical
   Medical Center                        School




 Screening Guidelines and Treatment
Options for Abdominal Aortic Aneurysms


                 Allen Jeremias, MD
                Division of Cardiology
AAA

•   Normal size: 2 cm
•   AAA: 3 cm
•   Prevalence: 1.3% in men aged 45-54
                  BUT 12.5% in age 75-84
•   Risk factors: Same as CAD but mainly hereditary and
    tobacco
•   Natural history: Gradual expansion; mural thrombus
•   Complications: Rupture; thromboembolism;
    compression or erosion of adjacent structures
AAA
AAA-related Mortality
•   13th leading cause of
    death in US
•   Documented 15K but
    likely up to 30k deaths
    per year

•   Mean F/U of 8 years
Natural History
•   Yearly Growth Rates:
    0.19 cm for AAA 2.8 to 3.9 cm
    0.27 cm for AAA 4.0 to 4.5 cm
    0.35 cm for AAA 4.6 to 8.5 cm

•   Rupture Rate at 5 years:
    AAA >6 cm – 43% vs. 20% for smaller AAA

•   Estimated Risk of Rupture:
    0 in AAA less than 4.0 cm
    0.5 to 5% for AAA 4.0 to 4.9 cm
    3 to 15% for AAA 5.0 to 5.9 cm
    10 to 20% for AAA 6.0 to 6.9 cm
    20 to 40% for AAA 7.0 to 7.9 cm
    30 to 50% for AAA 8.0 cm
Clinical Presentation

•   Most AAA quiescent until rupture
•   Rarely Abd. pain or back pain
•   New pain and tenderness indicate recent
    expansion
•   Thromboembolism to lower extremities
•   Ruptured AAA: Triad of Abd. or back pain,
    hypotension, and pulsatile Abd. mass
Physical Examination

•   30% of asymptomatic AAA discovered
    during routine PE
•   Pulsatile large Abd. mass
•   Sensitivity of PR 22-96%
Screening – Benefit?


•   In men age 50+       49% decrease in AAA
    rupture in 5 years

•   In men age 50+       64% decrease in AAA rupture
    in 9 years



                                   Wilminek et al. JVS 2003
Screening – Benefit?

•   Population based study of 67,800 men aged 65-
    74 with random allocation to Abd. US
•   Yearly US for AAA> 3 cm and surgery for AAA>
    5.5cm or 1 cm progression within 1 year

•   4-year aneurysm-related mortality in control
    group: 0.33% vs. 0.19% (RR reduction 42%)

•   Total of 47 fewer deaths in screening group
                                     MASS: BMJ 2002
Screening – Cost

•   Additional cost in screening group: $3.5 million
•   Incremental cost-effectiveness ratio: $45,000 per
    life-year gained

•   10-year estimate: $12,500 per life-year gained

•   Recommendation: Screening for ‘high-risk’
    groups

                                      MASS: BMJ 2002
Screening Guidelines

Class I
• Men age 60+ with FHx of AAA         PE and US

Class IIa
• Men age 65 – 75 with h/o tobacco           PE and
   USx1

BUT: No screening for non-smokers and women!

                           ACC/AHA Guidelines for PVD; JACC 2006
Imaging - US

•   Optimal for screening – cheap, easy and
    no radiation exposure
•   Sensitivity almost 100%
•   No visualization of iliac arteries
•   Dependence on sonographer
•   2-3% of patients cannot be imaged
Imaging – CT/MRI

•   Better definition of AAA shape
•   Better image suprarenal AAA
•   Detection of other Abd. pathology
•   Other vascular structures visible (renal, iliac
    arteries)
Follow-up Surveillance

   Aortic diameter <3 cm — no further testing
   Aneurysm 3 to 4 cm — annual ultrasound
   Aneurysm 4 to 4.5 cm — ultrasound every six
    months
   Aneurysm >4.5 cm — referral to a vascular
    specialist



                                    Society for Vascular Surgery
Follow-up Surveillance

•   AAA <4.0 cm        annual US

•   AAA 4.0 – 5.4 cm      bi-annual US

•   Consider intervention when AAA >5.5 cm or >0.5
    cm expansion within 6 months
•   Also, intervention with Abd./back pain or
    tenderness and embolism

                               ACC/AHA Guidelines for PVD; JACC 2006
Observational Management

Class I
• Peri-operative BB therapy for Pt. with CAD
Class IIb
• BB therapy to reduce rate of AAA expansion


                              ACC/AHA Guidelines for PVD; JACC 2006
Intermediate Size AAA (4-5.5 cm)

UK Small Aneurysm trial

•   Randomized 1090 Pt.
    to surgery vs. US
    surveillance every 6
    months
•   Operative mortality
    5.4%

•   Mean F/U of 8 years
                           Lancet 1998
Intermediate Size AAA (4-5.5 cm)

US ADAM Study

•   Randomized 1136 Pt.
    to surgery vs. US
    surveillance every 6
    months
•   Operative mortality
    2.7%

•   Mean F/U of 5 years
                           Lederle et al., NEJM 2002
Therapy

Surgery

•   Peri-operative
    mortality 2.7-5.6%
•   40-70% mortality for
    ruptured AAA surgery
•   Significant morbidity
    (5-12 weeks before
    returning to normal life
    style)
Therapy

EVAR

•   Peri-operative
    mortality 1.0-2.4%
•   May have lower
    mortality for ruptured
    AAA surgery
•   Recovery within 1-3
    days
Surgery vs. EVAR
Therapy - EVAR
Therapy - EVAR
Surgery vs. EVAR

Dream Trial

•   Randomized 351 Pt. to
    surgery vs. EVAR
•   Peri-operative survival
    advantage with EVAR
    lost beyond 1 year


                              Blankensteijn et al., NEJM 2005

				
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