in the clinic Abdominal Aortic Aneurysmpresentation, therapy, and mortality of abdominal aortic aneurysm in the United States, 2001-2004. J Vasc Surg. 2007;45:891-9. [PMID: 17391899]

inthe

clinicin the clinic

AbdominalAortic Aneurysm

Screening and Prevention page ITC5-2

Diagnosis page ITC5-4

Treatment page ITC5-9

Practice Improvement page ITC5-14

CME Questions page ITC5-16

Physician WriterFrank A. Lederle, MD

Section Co-EditorsChristine Laine, MD, MPHDavid R. Goldmann, MDHarold C. Sox, MD

The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP),including PIER (Physicians’ Information and Education Resource) andMKSAP (Medical Knowledge and Self-Assessment Program). Annals ofInternal Medicine editors develop In the Clinic from these primarysources in collaboration with the ACP’s Medical Education and Publish-ing Division and with the assistance of science writers and physicianwriters. Editorial consultants from PIER and MKSAP provide expertreview of the content. Readers who are interested in these primaryresources for more detail can consult http://pier.acponline.org and otherresources referenced in each issue of In the Clinic.

The information contained herein should never be used as a substitute forclinical judgment.

CME objective: To review the screening and prevention, diagnosis, treatment, and practice improvement for abdominal aortic aneurysm.

© 2009 American College of Physicians

®

What factors increase the risk forAAA?Smoking is the most importantreversible risk factor for AAA. Inthe largest screening study (3), ahistory of cigarette smokingaccounted for 75% of all AAAs 4.0cm or greater in diameter. The asso-ciation with AAA is stronger forcurrent smokers than for formersmokers, increases with number ofyears smoked, and decreases withthe elapsed time after quitting.After adjustment for other risk fac-tors, AAA is several times morecommon in men than in women.Other factors associated with AAAinclude age, white race, and familyhistory of AAA (see Box).Abdominal aortic aneurysm is less common in patients with diabetes (3).

In a cross-sectional screening study,

126 196 veterans age 50 to 79 years under-

went ultrasonography to detect AAA.

Aneurysms 3.0 cm or greater in diameter

were present in 4.2% of participants. The

principal positive associations with AAA

were age, smoking, male sex, white race,

family history of AAA, and atherosclerotic

diseases. This study first described the sur-

prising and still unexplained inverse associ-

ation of AAA with diabetes (3).

© 2009 American College of Physicians ITC5-2 In the Clinic Annals of Internal Medicine 5 May 2009

An aneurysm is a failure of the arterial wall that results in a balloon-like dilatation of a segment of the artery. Aortic aneurysms constitutethe 14th leading cause of death in the United States and the 10th

leading cause of death in older men, who are the principal victims (1). Diag-nosis of abdominal aortic aneurysm (AAA) is important because the naturalhistory is that of continued enlargement with potentially catastrophic conse-quences. Because the condition may be entirely asymptomatic, and when symp-toms are present, they may be nonspecific, the internist is often the first to evaluate the patient. Thus, understanding the disease, optimal diagnostic meth-ods, and management are crucial for primary care practitioners.

Approximately 80% of aortic aneurysms occur between the renal arteries andthe aortic bifurcation. Abdominal aortic aneurysm is present in more than5% of older men who have smoked. Each year in the United States, AAArupture causes 4500 deaths; another 1400 deaths result from the 45 000repair procedures done to prevent rupture (2).

Screening andPrevention

1. Silverberg E, Boring

CC, Squires TS. Can-

cer statistics, 1990.

CA Cancer J Clin.

1990;40:9-26.

[PMID: 2104569]

2. McPhee JT, Hill JS,

Eslami MH. The

impact of gender on

presentation, therapy,

and mortality of

abdominal aortic

aneurysm in the

United States, 2001-

2004. J Vasc Surg.

2007;45:891-9.

[PMID: 17391899]

3. Lederle FA, Johnson

GR, Wilson SE, et al.

The aneurysm detec-

tion and manage-

ment study screening

program: validation

cohort and final

results. Aneurysm

Detection and Man-

agement Veterans

Affairs Cooperative

Study Investigators.

Arch Intern Med.

2000;160:1425-30.

[PMID: 10826454]

4. The UK Small

Aneurysm Trial Partic-

ipants. Mortality

results for ran-

domised controlled

trial of early elective

surgery or ultrasono-

graphic surveillance

for small abdominal

aortic aneurysms.

Lancet.

1998;352:1649-55.

[PMID: 9853436]

What is the natural history ofAAA?The natural history of AAA is toenlarge slowly over a period of years.Abdominal aortic aneurysms of 4.0to 5.5 cm enlarge at a mean rate of0.3 cm per year, with less than 25%enlarging 0.5 cm or more per year(4, 5). Larger AAAs enlarge faster.The rate of enlargement for 3.0- to4.0-cm AAAs is one half that of4.0-to 5.5-cm AAAs (6), and onehalf again faster for AAAs greaterthan 5.5 cm (7). The enlargementrate differs among individuals andis faster with advancing age andcontinued smoking.

Most AAAs never rupture, butwhen rupture occurs, the mortal-ity rate is 80% (8). As a AAAenlarges, the risk for ruptureincreases. The rupture rate forAAAs of 4.0 to 5.5 cm in diame-ter is 0.7% to 1.0% per year (4, 5),higher than with AAAs less than4.0 cm. The rupture rate for smallAAA is higher in women than inmen (9). Men and women haveequivalent rupture rates for AAAsgreater than 5.5 cm (10). Rupturerates of AAAs greater than 5.5cm in otherwise healthy patientsare unknown and unlikely to beknown in the future because of

5. Aneurysm Detection

and Management

Veterans Affairs

Cooperative Study

Group. Immediate

repair compared with

surveillance of small

abdominal aortic

aneurysms. N Engl J

Med. 2002;346:1437-

44. [PMID: 12000813]

6. Santilli SM, Littooy FN,

Cambria RA, et al.

Expansion rates and

outcomes for the 3.0-

cm to the 3.9-cm

infrarenal abdominal

aortic aneurysm. J

Vasc Surg.

2002;35:666-71.

[PMID: 11932660]

7. Veterans Affairs Coop-

erative Study #417

Investigators. Rupture

rate of large abdomi-

nal aortic aneurysms

in patients refusing

or unfit for elective

repair. JAMA.

2002;287:2968-72.

[PMID: 12052126]

8. Adam DJ, Mohan IV,

Stuart WP, et al. Com-

munity and hospital

outcome from rup-

tured abdominal aor-

tic aneurysm within

the catchment area

of a regional vascular

surgical service. J

Vasc Surg.

1999;30:922-8.

[PMID: 10550191]

© 2009 American College of PhysiciansITC5-3In the ClinicAnnals of Internal Medicine5 May 2009

general agreement that thesepatients need treatment. How-ever, in patients with AAAgreater than 5.5 cm who are unfitfor surgery, the rupture rate ishigh (7).

A 5-year prospective longitudinal study

followed 198 patients with AAA 5.5 cm or

greater who were not repaired electively

because of high operative risk or patient

refusal. More than one half of the

patients died during the study, 30%

within 1 year of enrollment. The rate of

probable AAA rupture was 10% per year

in the entire cohort, and more than 25%

at 6 months for AAA 8.0 cm or greater.

Whether these rates apply to healthier

patients is unknown, but they are useful

for decision making in high operative risk

patients (7).

Who should clinicians screen forAAA and how should screening bedone?The U.S. Preventive Services TaskForce (USPSTF) now recommendsone-time screening with ultra-sonography to detect asympto-matic AAA in 65- to 75-year-oldmen who have ever smoked (11).The USPSTF does not make arecommendation for nonsmokingmen and recommends againstscreening women.

Medicare covers abdominal ultra-sonography to screen for AAA formen who have ever smoked andanyone with a family history ofAAA. Screening should take placeat the Welcome to Medicare visit,which must occur within 6months after beginning Medicareinsurance coverage.

The USPSTF based its recommen-dation to screen for AAA on asolid body of evidence. Four ran-domized trials of AAA screeninghave reported results. These trialsrandomly assigned one half ofpatients from a population list toreceive an invitation for ultrasono-graphy screening. Of these, 60% to80% attended the screening. Of themen who were screened, 4% to 8%

had AAAs 3.0 cm in diameter orlarger, and the frequency of electiveAAA repair was several-fold greaterin the invited groups than in theuninvited control groups. In ameta-analysis of these 4 trials per-formed for the USPSTF, meninvited to undergo screening had alower rate of AAA-related mortal-ity (odds ratio, 0.57 [95% CI, 0.45to 0.74]) (12).

In the Multicentre Aneurysm Screening

Study (MASS) conducted in the United

Kingdom, 67 770 men age 65 to 74 years

were randomly assigned to ultrasonogra-

phy screening for AAA or usual care.

Patients with AAA 5.5 cm or larger were

referred for elective repair. After a mean 7

years of follow-up, deaths related to AAA

were significantly reduced from 196 in the

control group to 105 in the invited group.

All-cause mortality was lower in the

screened group; the difference was of bor-

derline statistical significance (13).

A recent meta-analysis of longer-term out-

comes from the screening trials reported a

small but statistically significant reduction

in all-cause mortality in the invited

patients (odds ratio, 0.97 [95% CI, 0.94 to

0.99]) (14).

These trials, added to those ofsmaller studies, form the basis ofthe USPSTF recommendation forAAA screening (11). They were notlimited to smokers and did notreport their results by such sub-groups as smoking status becausethe authors had little informationabout the control groups. The firsttrial included 9342 women, whodid not benefit from screening.However, the number of

Risk Factors for Abdominal AorticAneurysm• Older age• Smoking• Male sex• White race• Family history of abdominal aortic

aneurysm• Occlusive atherosclerotic disease

9. Brown LC, Powell JT.

Risk factors for

aneurysm rupture in

patients kept under

ultrasound surveil-

lance. UK Small

Aneurysm Trial Partic-

ipants. Ann Surg.

1999;230:289-96; dis-

cussion 296-7.

[PMID: 10493476]

10. Powell JT, Brown LC,

Greenhalgh RM, et al.

The rupture rate of

large abdominal aor-

tic aneurysms: is this

modified by anatom-

ical suitability for

endovascular repair?

Ann Surg.

2008;247:173-9.

[PMID: 18156938]

11. U.S. Preventive Ser-

vices Task Force.

Screening for

abdominal aortic

aneurysm: recom-

mendation state-

ment. Ann Intern

Med. 2005;142:198-

202.

[PMID: 15684208]

12. Fleming C, Whitlock

EP, Beil TL, et al.

Screening for

abdominal aortic

aneurysm: a best-

evidence systematic

review for the U.S.

Preventive Services

Task Force. Ann

Intern Med.

2005;142:203-11.

[PMID: 15684209]

13. Multicentre

Aneurysm Screening

Study Group. A sus-

tained mortality ben-

efit from screening

for abdominal aortic

aneurysm. Ann

Intern Med.

2007;146:699-706.

[PMID: 17502630]

14. Lindholt JS, Norman

P. Screening for

abdominal aortic

aneurysm reduces

overall mortality in

men. A meta-analysis

of the mid- and

long-term effects of

screening for

abdominal aortic

aneurysms. Eur J

Vasc Endovasc Surg.

2008;36:167-71,

response to com-

ment, 621-2.

[PMID: 18485756]


AAA-related events in women wastoo small (10 ruptures in thescreened group vs. 9 in the controlgroup after 10 years of follow-up)to draw firm conclusions about theeffect of screening in women (15).

Several screening programs havereported the findings of repeatscreening (16, 17). Aneurysmswere less frequent and smallerthan on the initial screening,which is not surprising becausethe initial screening would havedetected the long-standing andtherefore larger AAAs that haddeveloped over the preceding

years. Consequently, most authorsand the USPSTF have concludedthat one-time screening after age65 is sufficient.

What should clinicians tellpatients to help them decreasetheir risk for AAA?Because the association with AAAis substantially stronger for cur-rent smokers than former smok-ers, it is reasonable to assume thatsmoking cessation will reduce therisk for AAA. Clinicians can citeincreased risk for AAA as anotherreason for patients to stop smoking.

Screening and Prevention... Abdominal aortic aneurysm is the 10th most commoncause of death in older men. Smoking is its most important modifiable risk factor,and former smokers have a progressively smaller risk for AAA than current smok-ers. Randomized trials show that screening substantially reduces the risk for AAA-related mortality. The USPSTF recommends one-time abdominal ultrasonographyscreening for male smokers age 65 to 75 years.

CLINICAL BOTTOM LINE

Diagnosisdespite descriptions of its variedpresentations dating back morethan a century. Although rupturedAAA usually presents with cata-strophic vascular collapse, it canpresent with normal blood pres-sure and hematocrit, althoughleukocytosis is usually present.Many physicians are unfamiliarwith the syndromes of sympto-matic unruptured AAA, in whichabdominal, flank, or back painprecedes rupture, and containedAAA rupture, in which thehematoma is sealed off in theretroperitoneum. Either of thesesyndromes can persist for days or,rarely, weeks before uncontainedrupture leads to death (19). Theclinician must be suspicious of thepossible presence of AAA whenencountering such symptoms inthe appropriate context. Interven-tion can be lifesaving.

How does AAA present?Before rupture, AAAs are nearlyalways asymptomatic. Detectionoccurs after abdominal palpation,radiologic imaging for other pur-poses, or imaging tests done toscreen for AAA. This sectionfocuses on diagnosing rupturedAAA, because it happens infre-quently in a physician’s career andis one of the true emergencies ofmedical practice.

Ruptured AAA is a leading causeof sudden death (18). Its most fre-quent findings are pain and tender-ness in the abdomen, flank, groin,or back. Other common symptomsinclude urinary retention, constipa-tion, urge to defecate, hypotension,transient syncope, sudden collapse,and shock.

Misdiagnosis of ruptured AAAremains disturbingly common,


15. Scott RA, Bridgewa-

ter SG, Ashton HA.

Randomized clinical

trial of screening for

abdominal aortic

aneurysm in

women. Br J Surg.

2002;89:283-5.

[PMID: 11872050]

16. Lederle FA, Johnson

GR, Wilson SE, et al.

Yield of repeated

screening for

abdominal aortic

aneurysm after a 4-

year interval.

Aneurysm Detection

and Management

Veterans Affairs

Cooperative Study

Investigators. Arch

Intern Med.

2000;160:1117-21.

[PMID: 10789604]

17. Hafez H, Druce PS,

Ashton HA. Abdomi-

nal aortic aneurysm

development in

men following a

“normal” aortic ultra-

sound scan. Eur J

Vasc Endovasc Surg.

2008;36:553-8.

[PMID: 18718773]

18. Thomas AC, Knap-

man PA, Krikler DM,

et al. Community

study of the causes

of “natural” sudden

death. BMJ.

1988;297:1453-6.

[PMID: 3147014]

19. Lederle FA, Parenti

CM, Chute EP. Rup-

tured abdominal

aortic aneurysm: the

internist as diagnos-

tician. Am J Med.

1994;96:163-7.

[PMID: 8109601]

20. Lederle FA, Simel DL.

The rational clinical

examination. Does

this patient have

abdominal aortic

aneurysm? JAMA.

1999;281:77-82.

[PMID: 9892455]

How should clinicians use thehistory and physical examinationin diagnosing AAA?Unruptured AAAAlthough unruptured AAAs arealmost always asymptomatic, a his-tory of heavy tobacco use or a fam-ily history of AAA should heightenawareness in older persons, particu-larly men. The only physical exam-ination maneuver of demonstratedvalue is abdominal palpation todetect a widened aortic pulsation or“pulsatile mass”.

Physicians who care for olderpatients should become proficientat measuring the width of the aortabetween the 2 index fingers. Thewidth of the aortic pulsation pro-vides the key evidence of AAA, notits prominence or force, the pres-ence of bruits, or other findings.Palpating an AAA seems to besafe: No one has reported ruptureimmediately following palpation.However, abdominal palpationmisses many AAAs 5.0 cm orlarger in diameter and is even lesssensitive for smaller AAAs or inobese patients.

A systematic review pooled 15 studies

involving 2955 participants not previously

known to have AAA. Each was screened

with both abdominal palpation and ultra-

sonography, which served as the diagnos-

tic reference standard. The sensitivity of

abdominal palpation ranged from 29%

for AAA 3.0 to 3.9 cm, to 50% for AAA 4.0

to 4.9 cm, and 76% for AAA 5.0 cm or

greater. The positive predictive value of

palpation for detecting AAA 3.0 cm or

greater was 43%. Abdominal obesity

seemed to decrease the sensitivity of pal-

pation. The authors concluded that

abdominal palpation had moderate sensi-

tivity for detecting AAAs large enough to

be referred for surgery, but could not be

used to exclude AAA (20).

On the basis of the estimates fromthis systematic review, a negativephysical examination reduces theodds that the patient has an AAA5.0 cm or larger by approximately25%. On the other hand, if the

examiner feels a pulsatile mass,imaging confirmation, usually ultra-sonography, is mandatory.

Ruptured AAAThe diagnosis of ruptured AAAcan be obvious or difficult. Themost important prerequisite is ahigh index of suspicion, especiallyin an older man who has smoked.Physicians must know the variouspresentations and be particularlysuspicious when the patient’s con-dition seems more serious thanwould be typical with an alternativeexplanation for flank or abdominalpain, such as pyelonephritis, diverti-culitis, or lumbar disk herniation.The Box lists signs and symptomsof ruptured AAA.

A pulsatile mass may be present butis often absent and should not berelied on to confirm rupture.Although ruptured AAAs tend tobe large, palpating one can be diffi-cult because of abdominal tender-ness, guarding, and intestinal dis-tention due to ileus. Studies ofruptured AAA that include post-mortem diagnoses of rupture havereported that a pulsatile mass ispalpable only about 50% of thetime (20), which means that anegative examination is very unre-liable. Table 1 describes the differ-ential diagnosis of pulsatile massand ruptured AAA, and Table 2lists the history and physicalexamination elements for rupturedand unruptured AAA.

Signs and Symptoms of RupturedAAA• Pain in the flank, abdomen, groin, or

back• Abdominal, flank, or back tenderness• Gastrointestinal dysfunction (constipa-

tion, distention, bleeding, urge todefecate)

• Urinary dysfunction (retention, difficulty voiding, renal colic)

• Syncope• Hypotension and shock

21. Lederle FA, Wilson

SE, Johnson GR, et al.

Variability in meas-

urement of abdomi-

nal aortic

aneurysms. Abdomi-

nal Aortic Aneurysm

Detection and Man-

agement Veterans

Administration

Cooperative Study

Group. J Vasc Surg.

1995;21:945-52.

[PMID: 7776474]


Table 1. Differential Diagnosis of Pulsatile Mass and Ruptured Abdominal Aortic AneurysmDisease Characteristics Notes

Pulsatile massNormal aorta Examiner may be misled by prominent Clinical observation*

pulsation or subcutaneous fatPara-aortic nodes Mass adherent to normal aorta that can

transmit the aortic pulsationRuptured abdominal aortic aneurysm†

Gastrointestinal disease (such Abdominal pain, constipation, The expanding hematoma can as diverticulitis, bowel ischemia, leukocytosis cause gastrointestinal symptomspancreatitis, penetrating duodenal ulcer, by compressing the bowel.malignant conditions) Reduced blood pressure and

obstruction of aortic brancharteries can compromise bloodsupply to the gastrointestinal andurinary tracts.

Urinary tract disease (such as Flank pain, urinary retention, The expanding hematomastones, infection) leukocytosis can compress the ureters.

Reduced blood pressure andobstruction of aortic brancharteries can compromise bloodsupply to the urinary tract.

Spinal diseases (such as herniated disk, Severe back pain, nerve impingement bony metastases, lower extremity syndromesneuropathy)Incarcerated hernia Inguinal mass with pain and AAA often diagnosed at

tenderness surgery for incarcerated hernia‡

AAA = abdominal aortic aneurysm.* Nusbaum JW, Freimanis AK, Thomford NR. Echography in the diagnosis of abdominal aortic aneurysm. Arch Surg.1971;102:385-8. [PMID: 5553311]† Lederle FA, Parenti CM, Chute EP. Ruptured abdominal aortic aneurysm: the internist as diagnostician. Am J Med.1994;96:163-7. [PMID: 8109601]‡ Khaw H, Sottiurai VS, Craighead CC, Batson RC. Ruptured abdominal aortic aneurysm presenting as symptomatic inguinalmass: report of six cases. J Vasc Surg. 1986;4:384-9. [PMID: 3761483]

Table 2. History and Physical Examination Elements for Abdominal Aortic AneurysmCategory Element Sensitivity, % Specificity, % Likelihood Likelihood

Ratio Ratio Positive Negative

Unruptured abdominal aortic aneurysm

History Usually asymptomaticPhysical examination Abdominal palpation

AAA ≥3.0 cm 39 97 12.0 0.72AAA ≥4.0 cm 60 15.6 0.51AAA ≥5.0 cm 76All AAA ≤81 99.2

Ruptured abdominal aortic aneurysm

History Pain in abdomen, flank, 80–100or backConstipation 22Urinary retention 22Syncope 26

Physical examination Abdominal palpation for 40–60pulsatile abdominal massHypotension 50–70Abdominal tenderness 70–90Ecchymosis anywhere between diaphragm and knees

AAA = abdominal aortic aneurysm.

In an ultrasonography screening study

(23), 4176 men age 65 to 73 years had

aortic diameter measurements by 2

different examiners. The mean inter-

observer difference was 0.1 mm, a high

degree of agreement.

Other tests have a very limitedrole. Plain abdominal radiographyoccasionally identifies AAA byshowing calcium deposits in theaneurysm wall, but has low sensi-tivity and does not provide anadequate measurement of AAAdiameter. Computed tomography(CT) may be useful when ultra-sonography fails to visualize theaorta clearly.

Ruptured AneurysmTable 3 lists laboratory and otherstudies for demonstration of AAA.Diagnosing a ruptured aneurysmmeans demonstrating extravascularblood in the retroperitoneum or

What imaging studies and otherlaboratory tests should cliniciansorder to evaluate patients withsuspected AAA?Unruptured AneurysmUltrasonography is the preferredtest for diagnosis and surveillanceof AAA in asymptomaticpatients. It is safe, accurate,and relatively inexpensive.When the examination is ade-quate, ultrasonography has a sen-sitivity and specificity of nearly100%. Bowel gas may cause aninadequate study, but a repeatedexamination after fasting is usu-ally successful. Lack of precision(usually <0.5 cm) may misclassifysome patients (21). Many inter-national organizations have concluded that diagnostic ultra-sonography has no verifiedadverse effects (22) and thereforeno contraindications.

22. Barnett SB, Ter Haar

GR, Ziskin MC, et al.

International recom-

mendations and

guidelines for the

safe use of diagnos-

tic ultrasound in

medicine. Ultra-

sound Med Biol.

2000;26:355-66.

[PMID: 10773365]


Table 3. Laboratory and Other Studies for Demonstration of Abdominal AorticAneurysm RuptureTest Sensitivity, % Specificity, % Notes

Abdominal 4 Using operative findings and clinical outcome ultrasonography as gold standard*.

Computed 79 77 Using operative findings as gold standard†.tomography 77 100 Differences between studies probably result

90 93 from the small number of patients.94 95

MR, MRA, Time is of the essence in the diagnosis of angiography rupture. MR, MRA, and angiography offer no

advantage over computed tomography andtake more time. Therefore, they are rarely ifever used for this purpose; therefore, operat-ing characteristics have not been reported.

Leukocyte count 70 Using operative findings, computed >11 x 109 cells/L tomography, or autopsy as gold standard‡.Hemoglobin <11 g/dL

MRA = magnetic resonance angiography.* Shuman WP, Hastrup W Jr, Kohler TR, et al. Suspected leaking abdominal aortic aneurysm: use ofsonography in the emergency room. Radiology. 1988;168:117-9. [PMID: 3289085]† Lederle FA, Wilson SE, Johnson GR, et al. Variability in measurement of abdominal aortic aneurysms.Abdominal Aortic Aneurysm Detection and Management Veterans Administration Cooperative StudyGroup. J Vasc Surg. 1995;21:945-52. [PMID: 7776474]Adam DJ, Bradbury AW, Stuart WP, et al. The value of computed tomography in the assessment of sus-pected ruptured abdominal aortic aneurysm. J Vasc Surg. 1998;27:431-7. [PMID: 9546228]Weinbaum FI, Dubner S, Turner JW, Pardes JG. The accuracy of computed tomography in the diagnosisof retroperitoneal blood in the presence of abdominal aortic aneurysm. J Vasc Surg. 1987;6:11-6.[PMID: 3599277]Zarnke MD, Gould HR, Goldman MH. Computed tomography in the evaluation of the patient withsymptomatic abdominal aortic aneurysm. Surgery. 1988;103:638-42. [PMID: 3375990]Kvilekval KH, Best IM, Mason RA, Newton GB, Giron F. The value of computed tomography in the man-agement of symptomatic abdominal aortic aneurysms. J Vasc Surg. 1990;12:28-33. [PMID: 2374251]‡ Lederle FA, Parenti CM, Chute EP. Ruptured abdominal aortic aneurysm: the internist as diagnosti-cian. Am J Med. 1994;96:163-7. [PMID: 8109601]


abdomen, which requires theresolving power of CT or magneticresonance imaging (MRI). If treat-ing the ruptured AAA is a realisticoption, obtain one of these testsimmediately when you suspect ruptured AAA and the patient ishemodynamically stable.

Computed tomography has 80%to 90% sensitivity for rupture(24). One study (25) demon-strated the difficulty of interpret-ing images in patients with sus-pected rupture. The authors foundthat multiple readings of CTagreed only moderately well aboutthe presence of rupture (K = 0.59interobserver, 0.69 intraobserver).Ultrasonography has low sensitiv-ity for rupture (26) but couldincrease the probability of thediagnosis by detecting a previ-ously undiagnosed AAA.

How do testing strategies differ depending on the initial presentation of AAA?Unruptured AneurysmWhen asymptomatic AAA is sus-pected (usually on the basis ofabdominal palpation or plain radio-graphy findings), abdominal imagingwith ultrasonography or CT willconfirm the diagnosis. Ultrasonogra-phy is preferred because it does notexpose the patient to radiation and isless expensive.

Suspected AAA RuptureWhen the presentation strongly sug-gests a ruptured AAA and thepatient is hemodynamically stable,obtain CT or MRI immediately,and be prepared for the occasional

ruptural AAA patient who hascardiovascular collapse in theradiology suite (19). For a patientwith abdominal pain and shock,obtain surgical consultationurgently to consider taking thepatient directly to the operatingroom. Abdominal ultrasonogra-phy can then be obtained whileresuscitation procedures areunderway.

When suspicion of AAA ruptureis lower, as in an elderly malesmoker with new onset of abdom-inal or back pain and clinical indicators of another diagnosis,physicians should still stronglyconsider obtaining abdominalultrasonography. Although ultra-sonography will not reliably diag-nose rupture, finding an AAA inthese patients will alert the phys-ician to pursue further evaluationwith CT or MRI.

What other disorders shouldclinicians consider in patientswith suspected AAA?Occasionally, para-aortic lymphnodes and lymphoma are largeenough to masquerade as AAA onabdominal palpation, ultrasono-graphy, and even CT (27, 28). Avariety of acute disorders of thegastrointestinal tract, urinary tract,and spine can produce symptomssimilar to ruptured AAA, but thefirst priority should be to excluderupture rather than pursue theseless serious conditions. Misdiag-noses resulting from similaritiesbetween ruptured AAA and otherconditions have been documented(19, 29).

23. Lindholt JS, Vammen

S, Juul S, et al. The

validity of ultrasono-

graphic scanning as

screening method for

abdominal aortic

aneurysm. Eur J Vasc

Endovasc Surg.

1999;17:472-5.

[PMID: 10375481]

24. Adam DJ, Bradbury

AW, Stuart WP, et al.

The value of com-

puted tomography in

the assessment of sus-

pected ruptured

abdominal aortic

aneurysm. J Vasc Surg.

1998;27:431-7.

[PMID: 9546228]

25. Gloviczki P, Pairolero

PC, Mucha P Jr, Farnell

MB, Hallett JW Jr,

Ilstrup DM, et al. Rup-


tic aneurysms: repair

should not be denied.

J Vasc Surg.

1992;15:851-7; discus-

sion 857-9.

[PMID: 1578541]

26. Shuman WP, Hastrup

W Jr, Kohler TR, et al.

Suspected leaking

abdominal aortic

aneurysm: use of

sonography in the

emergency room.

Radiology.

1988;168:117-9.

[PMID: 3289085]

27. Nusbaum JW, Freima-

nis AK, Thomford NR.

Echography in the

diagnosis of abdomi-

nal aortic aneurysm.

Arch Surg.

1971;102:385-8.

[PMID: 5553311]

28. Carro C, Camilleri L,

Garcier JM, et al.

Periaortic lymphoma

mimicking aortic

aneurysm. Eur J Car-

diothorac Surg.

2004;25:1126.

[PMID: 15145022]

29. Valentine RJ, Barth MJ,

Myers SI, et al. Nonvas-

cular emergencies

presenting as rup-


tic aneurysms.

Surgery. 1993;113:286-

9. [PMID: 8441963]

30. UK Small Aneurysm

Trial Participants.

Abdominal aortic

aneurysm expansion:

risk factors and time

intervals for surveil-

lance. Circulation.

2004;110:16-21.

[PMID: 15210603]

31. Smoking, lung func-

tion and the progno-

sis of abdominal aortic

aneurysm. The UK

Small Aneurysm Trial

Participants. Eur J Vasc

Endovasc Surg.

2000;19:636-42.

[PMID: 10873733]

Diagnosis... Most AAAs are diagnosed as an incidental finding during a physicalexamination. The most important factor in successfully diagnosing ruptured AAA isremembering to think of it in a person with new abdominal or flank pain.Although ultrasonography is an excellent test for unruptured AAA, making a defi-nite diagnosis of ruptured AAA requires showing blood in the retroperitoneum orabdomen, which requires CT or MRI.



32. Propanolol

Aneurysm Trial

Investigators. Propra-

nolol for small

abdominal aortic

aneurysms: results of

a randomized trial. J

Vasc Surg.

2002;35:72-9.

[PMID: 11802135]

33. Wilmink ABM, Hub-

bard CSFF, Day NE,

et al. Effect of pro-

pranolol on the

expansion of

abdominal aortic

aneurysms: a ran-

domized study

[Abstract]. Br J Surg.

2000;87:499.

34. Vammen S, Lindholt

JS, Ostergaard L, et

al. Randomized dou-

ble-blind controlled

trial of roxithromycin

for prevention of

abdominal aortic

aneurysm expan-

sion. Br J Surg.

2001;88:1066-72.

[PMID: 11488791]

35. Mosorin M, Juvonen

J, Biancari F, et al.

Use of doxycycline

to decrease the

growth rate of

abdominal aortic

aneurysms: a ran-

domized, double-

blind, placebo-con-

trolled pilot study. J

Vasc Surg.

2001;34:606-10.

[PMID: 11668312]

36. ACES Investigators.

Azithromycin for the

secondary preven-

tion of coronary

events. N Engl J

Med. 2005;352:1637-

45. [PMID: 15843666]

37. Pravastatin or Ator-

vastatin Evaluation

and Infection Ther-

apy Thrombolysis in

Myocardial Infarc-

tion 22 Investigators.

Antiobiotic treat-

ment of Chlamydia

pneumoniae after

acute coronary syn-

drome. N Engl J

Med. 2005;352:1646-

54. [PMID: 15843667]

38. Velicer CM, Heckbert

SR, Lampe JW, et al.

Antibiotic use in

relation to the risk of

breast cancer. JAMA.

2004;291:827-35.

[PMID: 14970061]

39. Powell JT, Brown LC,

Forbes JF, et al. Final

12-year follow-up of

surgery versus sur-

veillance in the UK

Small Aneurysm

Trial. Br J Surg.

2007;94:702-8.

[PMID: 17514693]

TreatmentWhat lifestyle modificationsshould clinicians recommend topatients with AAA?Smokers with AAA should receiveassistance with smoking cessation,which could help prevent diseaseprogression. Data from the UKSmall Aneurysm Trial groupdemonstrate that, compared withformer smokers, AAA enlargedmore rapidly in current smokers(30) and was more likely to rupture(9, 31).

What is the role of drug therapyin the management of patientswith asymptomatic AAA?Medical treatment to reduce the rate of enlargement of small AAAsis an area of active research, but notreatments have been proven effec-tive. Targets of therapy include sev-eral purported pathophysiologicmechanisms, including hemodynam-ics, inflammation, and proteaseactivity. Doxycycline, statins, andangiotensin-converting enzymeinhibitors have shown promisingresults, but all remain unproven andare not recommended outside ofrandomized trials.

Antihypertensive AgentsIn the only large trials (32, 33), theβ-blocker propranolol did not slowthe rate of AAA enlargement. How-ever, increased mean blood pressureis associated with increased risk forAAA rupture (9), so AAA is yetanother reason to treat hypertension,which should be managed with theusual therapy.

AntibioticsInterest in antibiotic therapy isbased on evidence of chronicinflammation in AAA, inhibitionof proteases and of inflammationby some antibiotics, and possibleinvolvement of Chlamydia pneumo-niae in the pathogenesis of AAA.Two small randomized trials havereported reduced rates of AAAenlargement in the months

following a course of antibiotics,but substantial losses to follow-upin one (34) and baseline differ-ences in the other (35) render thefindings inconclusive and prelimi-nary. Antibiotics have manyadverse effects, and the benefits inpatients with AAA remain uncer-tain. In large trials, antibioticsintended to prevent hypothesizedeffects of chlamydia infection onprogression of atherosclerosis didnot reduce cardiovascular events(36, 37). In addition, long-termuse of antibiotics has been associ-ated with an increased risk forbreast cancer (38). With uncertainbenefits and some known harms,the role of antibiotics in the long-term management of AAA is asyet undetermined.

When should clinicians recommendsurgery in patients withasymptomatic AAA?Elective AAA repair is indicatedwhen the risk for rupture is highenough to balance the risks of sur-gery. The strongest known predic-tor of AAA rupture is its maximalexternal diameter, which is theprincipal objective criterion foroffering elective repair. The rate ofenlargement seems as if it shouldpredict rupture, but current evi-dence provides no support forusing this measure. Therefore,the widely used rule is to considerAAA patients for repair only when the AAA exceeds 5.5 cm in diameter.

The United Kingdom Small Aneurysm Trial

(UKSAT) (4, 39) and the Aneurysm Detec-

tion and Management (ADAM) trial (5)

randomly assigned 1090 and 1136 pati-

ents, respectively, with AAA 4.0 to 5.4 cm in

diameter to immediate elective open repair

or periodic imaging surveillance leading to

repair when an AAA enlarged beyond

5.5 cm or became symptomatic. The pri-

mary outcome, all-cause mortality, was

the same in the 2 intervention groups in

both trials, as was quality of life, suggesting

that elective repair of AAA smaller than

5.5 cm did not change health outcomes.

Because of these influential trials, elective

repair is usually reserved for AAA larger

than 5.5 cm.

Do the outcomes of endovascularand open AAA repair differ?Open surgery is the traditionalmethod of AAA repair. The aortais exposed and cross-clamped, theaneurysm is opened, lumbar andother tributary arteries are tied off to control back bleeding, asynthetic graft is sewn into placeunder direct vision, and the aorta is then closed around thegraft. Elective open repair is asso-ciated with an operative mortalityrate of 2% to 5%, considerablemorbidity, and a long conva-lescence (Table 4).

In the National Inpatient Sample, 220 403

hospital discharges in the United States

from 2001 to 2004 were for AAA. A total of

45 000 repairs of intact AAA were per-

formed per year, with an in-hospital mor-

tality rate of 4.5% for open repair and

1.0% for endovascular repair. Of the 10

000 patients hospitalized for ruptured

AAA each year, 68% had surgery, with a

mortality rate of 37.3%. Women had a

substantially higher mortality rate than

men (2).

Endovascular repair involves intro-ducing an expandable graft systemthrough the femoral or iliac arteriesinto the aneurysmal region of theaorta and iliac arteries. When the

graft is in place, the AAA, whichremains intact, is not exposed toarterial pressure, which should pre-vent it from growing and rupturing.Endovascular repair requires a seg-ment of normal aorta below therenal arteries and also requires iliacarteries that are free of excessiveplaque or tortuosity. These require-ments exclude about one third ofpatients.

The advantages of endovascularrepair compared with open repairare reduced operative morbidity andshorter initial hospital stay andoverall recovery time. However,many studies have found thatendovascular repair is more expen-sive than open repair, due primarilyto the high price of the grafts. Inrandomized trials, endovascularrepair of AAA has lower periopera-tive mortality than open repair, butmortality rates after 2 years aresimilar (40, 41).

What criteria identify patientswho are candidates forendovascular versus openaneurysm repair?The long-term results of endovas-cular repair are unknown, althoughthe randomized trials are continu-ing to monitor outcomes. Becauseof the uncertainty about long-termresults, many physicians recom-mend open repair in youngerpatients.


40. EVAR trial partici-

pants. Endovascular

aneurysm repair ver-

sus open repair in

patients with

abdominal aortic

aneurysm (EVAR trial

1): randomised con-

trolled trial. Lancet.

2005;365:2179-86.

[PMID: 15978925]

41. Dutch Randomized

Endovascular

Aneurysm Manage-

ment (DREAM) Trial

Group. Two-year

outcomes after con-

ventional or

endovascular repair

of abdominal aortic

aneurysms. N Engl J

Med. 2005;352:2398-

405.

[PMID: 15944424]

42. EVAR trial partici-

pants. Endovascular

aneurysm repair and

outcome in patients

unfit for open repair

of abdominal aortic

aneurysm (EVAR trial

2): randomised con-

trolled trial. Lancet.

2005;365:2187-92.

[PMID: 15978926]

Table 4. Elective Endovascular Versus Open AAA RepairVariable Open Repair Endovascular Repair

Cost High HigherProportion of patients that 10%–20% 33%

can’t undergo procedurePerioperative mortality rate 2%–5% 0%–2%Postoperative complications Relatively low (8%) High (35%)Perioperative morbidity High LowOutcomes Initially worse but equivalent Initially better but equivalent

after 2 years after 2 yearsCertainty of very long-term Well documented Not known

outcomes4-year reintervention rates* 6% 20%

AAA = abdominal aortic aneurysm.* Ratzan RM, Donaldson MC, Foster JH, Walzak MP. The blue scrotum sign of Bryant: a diagnostic clueto ruptured abdominal aortic aneurysm. J Emerg Med. 1987;5:323-9. [PMID: 3624839]

The United Kingdom Endovascular

Aneurysm Repair trial 1 (EVAR-1) ran-

domly assigned 1082 patients with AAA

5.5 cm or greater to either open or endo-

vascular repair. Postoperative mortality

rate (30-day or inpatient) was signifi-

cantly lower in the endovascular group,

but after a median 2.9 years follow-up,

all-cause mortality was the same. Post-

operative complications occurred 4

times more frequently after endovascu-

lar repair (40).

Because endovascular repair is lessinvasive, vascular disease special-ists thought that high-riskpatients would have better out-comes with it. However, 2 ran-domized trials from the UnitedKingdom suggest otherwise. Inone study (42), endovascularrepair conferred no all-cause mor-tality advantage over open repairin the least fit randomized sub-group at 4 years. In the other(43), endovascular repair was notbeneficial in patients consideredunfit for open repair.

The United Kingdom Endovascular

Aneurysm Repair trial 2 (EVAR-2) ran-

domly assigned 338 patients unfit for

open repair with AAA 5.5 cm or greater to

have endovascular repair or observation.

All-cause mortality (the primary out-

come) and AAA-related mortality were

the same in the 2 groups. Ruptures before

delayed repair, high operative mortality,

and high cross-over rates led to questions

about the validity of the findings, but it is

the only randomized trial in this patient

population (42).

When should clinicians hospitalizepatients with AAA?Clinicians should hospitalizepatients for elective aneurysmrepair when the diameter of theAAA reaches 5.5 cm. Electiveopen or endovascular AAA surgery at a high-volume hospital(at least 30 cases per year) is asso-ciated with lower operative mortality (44, 45).

Hospitalize patients with sus-pected AAA rupture immediately

for emergency diagnostic testingand possible AAA repair, alsopreferably in a high-volume hospital (44).

How should clinicians managepatients with suspected rupturedAAA?If the patient has abdominal painand shock, surgical consultationshould be obtained urgently todecide whether to take the patientdirectly to the operating room and perform ultrasonographywhile resuscitation procedures are underway. If an imaging testshows AAA rupture, surgical consultation should be obtainedimmediately to decide whether to take the patient directly to theoperating room. Emergency repair is the patient’s only chancefor survival, according to caseseries that show that unrepairedAAA rupture is almost alwaysfatal. Case series have shown apossible survival advantage forendovascular compared with open repair for ruptured AAA,but observational studies of treatments are often unreliablebecause of confounding by indication and other selectionbiases. Researchers in the UnitedKingdom are beginning a ran-domized trial comparing openwith endovascular repair for ruptured AAA.

The syndrome of symptomaticunruptured AAA requires physicians to make a very diffi-cult decision. They should consider this syndrome when the patient has an AAA andabdominal, flank, or back pain but imaging does notdemonstrate rupture. The problem is whether to proceedwith immediate surgery. Symp-toms, the diameter of the AAA,other imaging findings, and thegeneral health of the patient arethe main factors to take intoaccount.


43. Brown LC, Green-

halgh RM, Howell S,

et al. Patient fitness

and survival after

abdominal aortic

aneurysm repair in

patients from the UK

EVAR trials. Br J Surg.

2007;94:709-16.

[PMID: 17514695]

44. Killeen SD, Andrews

EJ, Redmond HP, et

al. Provider volume

and outcomes for

abdominal aortic

aneurysm repair,

carotid endarterec-

tomy, and lower

extremity revascular-

ization procedures. J

Vasc Surg.

2007;45:615-26.

[PMID: 17321352]

45. Dimick JB, Upchurch

GR Jr. Endovascular

technology, hospital

volume, and mortal-

ity with abdominal

aortic aneurysm sur-

gery. J Vasc Surg.

2008;47:1150-4.

[PMID: 18440178]

When should clinicians consultspecialists in managing patientswith AAA?Obtain vascular surgery consulta-tion for asymptomatic AAA 5.5 cmor greater in outside diameter forpatients who are possible candi-dates for repair and for patientswith AAA who develop symptomsconsistent with rupture.

Cardiology consultation may behelpful before elective AAA repairfor advice on whether to do noninvasive testing or coronaryangiography in patients with coronary artery disease, diabetes,renal insufficiency, or poor func-tional status. Algorithms estab-lished by the American College of Cardiology/American HeartAssociation for evaluation before AAA repair identifypatients at increased risk for cardiac death following aortic surgery (46, 47). However, in arandomized trial, coronary revascularization before surgerydid not improve the perioperative

46. American College of

Cardiology.

ACC/AHA guideline

update for perioper-

ative cardiovascular

evaluation for non-

cardiac surgery—-

executive summary:

a report of the

American College of

Cardiology/Ameri-

can Heart Associa-

tion Task Force on

Practice Guidelines

(Committee to

Update the 1996

Guidelines on Peri-

operative Cardiovas-

cular Evaluation for

Noncardiac Surgery).

J Am Coll Cardiol.

2002;39:542-53.

[PMID: 11823097]

47. Samain E, Farah E,

Lesèche G, et al.

Guidelines for peri-

operative cardiac

evaluation from the

American College of

Cardiology/Ameri-

can Heart Associa-

tion task force are

effective for stratify-

ing cardiac risk

before aortic sur-

gery. J Vasc Surg.

2000;31:971-9.

[PMID: 10805888]

48. McFalls EO, Ward HB,

Moritz TE, et al. Coro-

nary-artery revascu-

larization before

elective major vas-

cular surgery. N Engl

J Med.

2004;351:2795-804.

[PMID: 15625331]


myocardial infarction rate or long-term mortality (48).

The Coronary Artery Revascularization

Prophylaxis (CARP) trial randomized 510

patients who were having elective open

abdominal surgery for AAA or arterial

occlusive disease and who had a coro-

nary stenosis of at least 70% to preoper-

ative coronary revascularization or no

revascularization (48). Patients were

excluded if they had unstable angina,

more than 50% left main disease, ejec-

tion fraction less than 20%, or severe

aortic stenosis. Revascularization did

not improve 30-day operative mortality,

myocardial infarction, or long-term

mortality rates (mean follow-up, 2.7

years). The findings suggest that cardiac

intervention is unnecessary for most

patients having elective AAA repair.

How should clinicians monitor patients with anasymptomatic AAA that does not meet the criteria for intervention?Table 5 lists elements of follow-up for AAA. In patients whoseAAA is below the threshold forelective repair, ultrasonography

Table 5. Elements of Follow-up for Abdominal Aortic AneurysmCategory Issue Method of Follow-up Frequency Notes

History Development of Ask about As soon symptoms abdominal, flank, as they occur

or back pain and at each visitPhysical Enlargement of Abdominal Each visit Optional, does

examination AAA examination not replaceultrasonography

Laboratory testing Enlargement of AAA diameter by Every 6 to 12 unrepaired AAA ultrasonography months, depending

on AAA diameterLaboratory testing Status of Computed Annually after first

endovascular graft tomography yearNondrug therapy Need for surgery Determine if size Each visit

of AAA is >5.5 cm; ask about symptoms

Drug therapy Treatment of Antihypertensives Ongoing Treatment of concurrent medical hypertension of problems, such as undetermined hypertension value for pre-

venting rupturePatient education Symptom Ask patients to Each visit

recognition in report abdominal, patients with flank, or AAA under back painobservation

AAA = abdominal aortic aneurysm.

49. American Associa-

tion for Vascular

Surgery. ACC/AHA

2005 guidelines for

the management of

patients with

peripheral arterial

disease (lower

extremity, renal,

mesenteric, and

abdominal aortic):

executive summary

a collaborative

report from the

American Associa-

tion for Vascular

Surgery/Society for

Vascular Surgery,

Society for Cardio-

vascular Angiogra-

phy and Interven-

tions, Society for

Vascular Medicine

and Biology, Society

of Interventional

Radiology, and the

ACC/AHA Task Force

on Practice Guide-

lines (Writing Com-

mittee to Develop

Guidelines for the

Management of

Patients With Periph-

eral Arterial Disease)

endorsed by the

American Associa-

tion of Cardiovascu-

lar and Pulmonary

Rehabilitation;

National Heart, Lung,

and Blood Institute;

Society for Vascular

Nursing; TransAt-

lantic Inter-Society

Consensus; and Vas-

cular Disease Foun-

dation. J Am Coll

Cardiol.

2006;47:1239-312.

[PMID: 16545667]

50. Grimshaw GM,

Thompson JM,

Hamer JD. A statisti-

cal analysis of the

growth of small

abdominal aortic

aneurysms. Eur J

Vasc Surg.

1994;8:741-6.

[PMID: 7828753]

51. McCarthy RJ, Shaw

E, Whyman MR, et al.

Recommendations

for screening inter-

vals for small aortic

aneurysms. Br J Surg.

2003;90:821-6.

[PMID: 12854107]

52. Hallett JW Jr, Mar-

shall DM, Petterson

TM, et al. Graft-

related complica-

tions after abdomi-

nal aortic aneurysm

repair: reassurance

from a 36-year pop-

ulation-based expe-

rience. J Vasc Surg.

1997;25:277-84; dis-

cussion 285-6.

[PMID: 9052562]


imaging surveillance to assessaneurysm diameter is recom-mended every 6 to 12 months if the AAA diameter is 4.0 to 5.4 cm and every 2 to 3 years if it is less than 4.0 cm (49).

As noted previously, a large ran-domized trial (5) showed thatimaging at intervals of 6 monthswas equivalent to a strategy ofimmediate repair of AAAs meas-uring 4.0 to 5.4 cm. Observa-tional studies that monitoredenlargement rates suggest thatsurveillance intervals of up to 3years are safe for smaller AAAs(6, 50, 51). In deciding when torecommend repair, physiciansshould remember that errors ofup to 0.5 cm in measuring thediameter of an AAA are commonwith abdominal ultrasonographyor CT (21).

How should clinicians monitorpatients after aortic aneurysmrepair?The monitoring strategy dependson the method of AAA repair.After open repair, the graft failure

rate is very low (about 0.3% peryear), and no specific follow-up is recommended (5, 52, 53).Endovascular repair is associatedwith more late graft problems (for example, endoleaks, graftmigration or kinking, continuedAAA enlargement) and resultingreinterventions. In the EVAR-1trial (40), 20% of patients ran-domly assigned to endovascularrepair required reinterventionwithin 4 years compared with 6%of those randomly assigned toopen repair. Current practice,which is derived from the deviceapproval trials but not based oncomparative trials, is to performCT at 1, 6, and 12 months afterendovascular repair and thenannually for the rest of thepatient’s life. This strategy is aconsiderable burden for bothpatients and vascular surgeons; isexpensive; and results in substan-tial radiation exposure, especiallywith the commonly used triphasicCT protocol. Alternative follow-up methods are under activeinvestigation.

Treatment... Elective repair of AAA is indicated when the external diameterreaches 5.5 cm. Below that size, randomized trials show that repair does notimprove outcomes. Smoking cessation treatment and control of high bloodpressure are indicated. Surveillance abdominal ultrasonography is indicated foraneurysms smaller than 5.5 cm, with more frequent surveillance as the diame-ter approaches 5.5 cm. The choice between open elective repair and endovascu-lar repair is difficult. Endovascular repair has less mortality and morbidity inthe perioperative period but all-cause mortality and other outcomes are equiv-alent by 2 years, and the very long-term outcomes of endovascular repair areunknown. The treatment for ruptured AAA is immediate repair, either open orendovascular.



inthe

clinicTool Kit

in the clinic

Abdominal Aortic Aneurysm

PIER Moduleswww.pier.acponline.orgAccess the following PIER module: Abdominal aortic aneurysm. PIER modules provide evidence-based, updated information on current diagnosis, treatment, and management, in anelectronic format designed for rapid access at the point of care.Patient Education Resourceswww.annals.org/intheclinic/AAA.htmlAccess the Patient Information material on the following page for duplication and distributionto patients.www.medicinenet.com/abdominal_aortic_aneurysmAbdominal Aortic Aneurysm index from Medicinenet.comClinical Guidelineswww.annals.org/cgi/reprint/142/3/198.pdfU.S. Preventive Services Task Force on screening for AAAQuality Measures for AAAqualityindicators.ahrq.gov/downloads/iqi/iqi_guide_v31.pdfGuide to Inpatient Quality Indicators, from the Agency for Healthcare Research and Quality(AAA is discussed on pp. 25, 26, 39, and 40)www.qualitymeasures.ahrq.gov/summary/summary.aspx?doc_id=12739Abdominal aortic aneurysm repair, from the National Quality Measures Clearinghouse

ultrasonography screening in menage 65 to 75 years old who have eversmoked or have a first-degree rela-tive with AAA; advice to stop smok-ing; open or endovascular repair ofAAA 5.5 cm or larger in diameter;imaging surveillance of AAA 4.0 to5.4 cm at 6- to 12-month intervalsand 2- to 3-year intervals for AAAless than 4.0 cm; and immediateevaluation and repair of rupturedAAA. However, the guideline con-tains several recommendations thatconflict with randomized trial find-ings, including long-term b-blockade to slow the rate of AAAenlargement. The guideline alsostates that “Repair can be beneficialin patients with infrarenal or juxta-renal AAAs 5.0 to 5.4 cm in diame-ter,” an opinion that prompted a let-ter of dissent from the directors ofthe 2 randomized trials (55).

How should clinicians educatepatients with AAA?Patients with AAA should knowabout the course, management, andprognosis of AAA and importantself-management issues, includingthe importance of smoking cessa-tion, the need to report symptomsimmediately, the scheduling of regu-lar follow-up visits for surveillancebefore repair and after endovascularrepair, and the available surgicaloptions. Physicians have a responsi-bility to provide them with thisinformation.

What do professionalorganizations recommend aboutthe care of patients with AAA?The U.S. Preventive Services TaskForce (USPSTF) recommends one-time screening for AAA with ultra-sonography in men age 65 to 75years who have ever smoked (11). Itdoes not recommend for or againstscreening in 65- to 75-year-old menwho have never smoked. The USPSTF recommends against rou-tine screening in women.

The Joint Council (54) recom-mended 5.5-cm diameter as theappropriate threshold for electiverepair in most patients, on the basisof the finding of 2 randomized trials(4, 5, 39) that patients did not bene-fit from repairing AAA less than 5.5cm in diameter. However, the Coun-cil also recommended repair ofsmaller AAA in various patientgroups, including women, youngerpatients, and patients of surgeonswhose operative mortality rate is low.The last recommendation is basedon weak evidence (observationalstudies) and personal opinion andconflicts with randomized trial evi-dence that repair of small aneurysmsconfers no benefit.

The American College of Cardiol-ogy and the American Heart Asso-ciation’s peripheral arterial diseaseguideline (49) contains a number ofwell-supported recommendationsabout AAA, including one-time

PracticeImprovement

53. Johnston KW. Non-

ruptured abdominal

aortic aneurysm: six-

year follow-up

results from the mul-

ticenter prospective

Canadian aneurysm

study. Canadian


Surgery Aneurysm

Study Group. J Vasc

Surg. 1994;20:163-

70. [PMID: 8040938]

54. Joint Council of the

American Associa-

tion for Vascular

Surgery and Society

for Vascular Surgery.

Guidelines for the

treatment of

abdominal aortic

aneurysms. Report

of a subcommittee

of the Joint Council

of the American

Association for Vas-

cular Surgery and


Surgery. J Vasc Surg.

2003;37:1106-17.

[PMID: 12756363]

55. Lederle FA, Powell

JT, Greenhalgh RM.

Repair of small

abdominal aortic

aneurysms [Letter].

N Engl J Med.

2006;354:1537-8.

[PMID: 16598058]

WHAT YOU SHOULD KNOWABOUT ABDOMINAL AORTICANEURYSM

In the ClinicAnnals of Internal Medicine

annals.org

What is an abdominal aortic aneurysm?

Blood moves from the heart to otherparts of the body through arteries.The abdominal aorta is the mainartery in the belly, which is alsocalled the abdomen. An abdominalaortic aneurysm (AAA) occurs whenthe wall of the aorta gets too big.This is caused by a weakening of thewall of the aorta. If the enlargedaorta breaks, blood can then leakinto the body.

Is AAA a big problem?

Yes. It is the 14th most common cause of death in theUnited States. In older men, it is the 10th mostcommon cause of death.

What are the symptoms of AAA?

There are no symptoms of AAA until it breaks. If blooddoes leak out, there may be pain in the back orbelly, weakness, or fainting.

How is AAA found?

The doctor may feel the AAA when pressing on thebelly. The best way to find AAA is by doing a testcalled an ultrasonography of the abdomen.

Who should have a screening test forAAA?

A screening test is done to look for a disease whenthere are no symptoms. Experts recommend thatolder men who smoke should have a screening testfor AAA. Experts do not recommend a screeningtest for other people.

Who is most likely to have an AAA?

Cigarette smoking makes the chances of having anAAA greater than anything else. Being older, ofwhite race, male, and a smoker all add to the riskfor having an AAA.

If screening finds AAA, what shouldbe done?

The greatest chance that the AAA could break is if it islarger than 2 in (5.5 cm). If it is smaller than 2 in,the doctor will do an ultrasonography test, tell thepatient to stop smoking, and treat the patient’shigh blood pressure. If the AAA is 2 in or more, doc-tors usually do surgery to fix it.

Pati

ent

Info

rmat

ion

For More Information

Web Sites With Information onAbdominal Aortic Aneurysm:

www.medem.com/medlib/article/ZZZVTBUUBZEJAMA Patient Page: Aortic Aneurysms

www.medicinenet.com/abdominal_aortic_aneurysmAbdominal Aortic Aneurysm index from

Medicinenet.com

© 2009 American College of Physicians In the Clinic Annals of Internal Medicine

CME Questions

A 75-year-old asymptomatic man under-goes his annual examination. He is obeseand has a long history of smoking, hyper-tension, and chronic kidney disease (crea-tinine level, 2.7 mg/dL [238.73 µmol/L]).His medications are furosemide, ramipril,atorvastatin, and aspirin.

On physical examination, the bloodpressure is 170/78 mm Hg bilaterally,and pulse rate is 70/min and regular.There is a 2/6 holosystolic murmur heardat the apex with radiation to the axilla.There is a soft systolic abdominal bruitand a mildly tender midline pulsatilemass. There are bilateral femoral bruitswith absent distal pulses. Laboratorystudies show a total cholesterol level of200 mg/dL (5.17 mmol/L), HDL choles-terol level of 32 mg/dL (0.83 mmol/L),and LDL cholesterol level of 132 mg/dL(3.41 mmol/L). The patient is encouragedto stop smoking.

In addition to increasing the antihyper-tensive medications, what is the mostappropriate next step in this patient’smanagement?

A. Abdominal radiographB. Abdominal computed tomography

scan with contrastC. Abdominal ultrasoundD. Contrast aortography

A 74-year-old woman undergoes a rou-tine evaluation. She is a smoker and hashypertension, hypercholesterolemia, andtype 2 diabetes mellitus. Last year, shehad an asymptomatic 4.4-cm infrarenalabdominal aortic aneurysm diagnosedduring an ultrasonography for suspectedgallstones, at which time she wasencouraged to stop smoking. She ispetite, active, asymptomatic, and com-pliant with her medications, whichinclude atenolol, glyburide, metformin,lisinopril, and aspirin.

On physical examination, the bloodpressure is 125/78 mm Hg, and thepulse rate is 70/min and regular. Thelungs are clear; cardiac examinationshows an S4, and abdominal examina-tion shows a nontender abdomen with a

pulsatile mass. A follow-up ultrasonog-raphy shows a 5.1-cm aneurysm withthrombus. The patient is again encour-aged to stop smoking.

What is the most appropriate next stepin this patient’s management?

A. Repeat ultrasonography in 6months

B. Increase atenolol, repeatultrasonography in 6 months

C. Elective aneurysm repairD. Start warfarin (international

normalized ration, 2–3), repeatultrasonography in 6 months

A 67-year-old woman comes to youroffice because of intermittent lower backpain of 4 days’ duration. The pain is dull,nonradiating, and nonpositional, and isunrelated to meals or exertion. She hasno dyspnea, chest pain, or dysuria, and nohistory of trauma. She has a history ofhypercholesterolemia and underwent acholecystectomy at age 45 years. She alsohas a history of recurrent urinary tractinfections. She stopped smoking 10 yearsago. Her only medication is simvastatin,20 mg every night orally.

On physical examination, blood pressureis 145/85 mm Hg and heart rate is 86beats/min and regular. The patient isafebrile. Jugular venous pressure is nor-mal. Carotid pulses are 2+ bilaterally,without bruits. Cardiac examinationshows S4; the findings are otherwisenormal. The lungs are clear to ausculta-tion. Abdominal examination shows amidline pulsatile mass. No spinal or cos-tovertebral angle tenderness is noted.Distal pulses are normal.

Laboratory findings include hematocritof 36%, leukocyte count of 9.5 × 109

cells/L, platelet count of 290 × 109

cells/L, and serum creatinine level of 1.5mg/dL (114.38 µmol/L). Results of uri-nalysis are normal. The LDL cholesterollevel is 115 mg/dL (2.98 mmol/L).Abdominal ultrasound shows a 4.8-cmabdominal aortic aneurysm that origi-nates from the celiac trunk and extendsbelow the renal arteries.

Which of the following is the mostappropriate next step?

A. Initiate treatment withmetoprolol, 25 mg twice a dayorally, and schedule a follow-upvisit with ultrasonography in 6months.

B. Increase the dose of simvastatinto 40 mg/d and schedule afollow-up visit withultrasonography in 3 months.

C. Hospitalize the patient, order ahigh-resolution computedtomography scan, and obtain avascular surgery consultation.

D. Hospitalize the patient; initiatetreatment with metoprolol, 25 mgtwice a day; and refer the patientto a vascular surgeon.

E. Initiate treatment withmetoprolol, 25 mg twice a dayorally, and order magneticresonance imaging of the spine.

A 72-year-old man is evaluated duringa routine examination. He has a 45-pack-year history of smoking but quitsmoking 10 years ago. He is fit andexercises aggressively. He has noknown coronary artery disease and nomedical problems.

On physical examination, BMI is 26.4kg/m2. Pulse rate is 62/min, and bloodpressure is 118/64 mm Hg. Serum totalcholesterol level is 175 mg/dL (4.53mmol/L), serum high-density lipoproteincholesterol level is 52 mg/dL (1.34mmol/L), serum low-density lipoproteincholesterol level is 102 mg/dL (2.64mmol/L), serum triglyceride level is 105mg/dL (1.19 mmol/L).

Which of the following is most appro-priate next step in the management ofthis patient?

A. Electron-beam computedtomography for calcium score

B. Carotid artery ultrasonographyC. Ultrasound to evaluate for

abdominal aortic aneurysmD. Statin therapy

Questions are largely from the ACP’s Medical Knowledge Self-Assessment Program (MKSAP). Go to www.annals.org/intheclinic/ to obtain up to 1.5 CME credits, to view explanations for correct answers, or to purchase the complete MKSAP program.

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Documents

in the clinic Abdominal Aortic Aneurysmpresentation, therapy, and mortality of abdominal aortic aneurysm in the United States, 2001-2004. J Vasc Surg. 2007;45:891-9. [PMID: 17391899]