Abdominal aortic aneurysm (AAA)
Abdominal aortic aneurysm (AAA)
endovascular repair associated with lower morbidity and mortality than open repair (N Engl J Med 2008 Jan 31)
Description:
abnormal dilatation of blood vessel
aneurysm = diameter 2 times normal lumen above and below
Also called:
atherosclerotic aortic aneurysm
Types:
atherosclerotic AAA is most common type
inflammatory AAA
variant of atherosclerotic AAA
dense fibrotic reaction of anterior and lateral walls of aneurysm and surrounding tissues (frequently duodenum)
associated with retroperitoneal fibrosis
surgical repair of inflammatory AAA
surgery more difficult due to inflammatory peel and many adhesions
mobilization of aneurysm may damage duodenum
patients tend to have more pain than with typical AAA
inflammation frequently recedes after repair
case presentation of inflammatory AAA can be found in Mayo Clin Proc 2002 Aug;77(8):849 full-text mycotic AAA
bacterial inflammation of arterial wall
most commonly Salmonella in infrarenal aorta
patient may have fever and evidence of septic embolization
blood tests may show increased WBC, positive blood cultures
aneurysm usually sacular, lacking calcifications
long-term antibiotics should be directed by culture and sensitivities
surgical exploration
if no periaortic purulence and negative Gram stain of proximal and distal artery - interposition of graft may be sufficient
if gross purulence - resection, close aorta, extra-anatomic (axillobifemoral) bypass
ruptured AAA
immediate surgical emergency
clinical diagnosis - consider as diagnosis until ruled out in any patient with hypotension, abdominal pain and palpable mass, shock
maintain systolic blood pressure 50-70 mmHg until aorta clamped
Organs Involved:
descending aorta, 75-95% infrarenal
Who is most affected:
advancing age, men
Incidence/Prevalence:
prevalence of AAA
varies from 1.3% to 8.9% in men and 1% to 2.2% in women (Lancet 2005 Apr 30;365(9470):1577)
varies from 2% to 7.8% (Ann Intern Med 1993 Sep 1;119(5):411 full-text)
prevalence of AAAs 2.9-4.9 cm varies with age, gender, family history and tobacco use
typical prevalence in men ranges from 1.3% at ages 45-54 years to 12.5% at ages 75-84 years
typical prevalence in women ranges from 0% at ages 45-54 years to 5.2% at ages 75-84 years
Reference - ACC/AHA 2005 guidelines (J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF)
prevalence of ruptured AAA
cause of death annually for about 1.2% males and 0.6% females > 65 years old
21-66% of patients survive to surgery, with 50% mortality following surgery
Reference - Ann Intern Med 1993 Sep 1;119(5):411 full-text HYPERLINK "javascript:changeView(%22Causes_and_Risk_Factors%22);"
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Causes and Risk Factors
Causes:
> 95% cases due to atherosclerosis in United States
mycotic AAA due to bacterial infection, most commonly SalmonellaPathogenesis:
intimal dissection causes aortic dilatation and creation of false lumen
Likely risk factors:
smoking
clinical vascular disease
male
older age
increased blood pressure
increased total cholesterol
family history of AAA
Reference - based on 6 cohort studies
Click for Details smoking most important risk factor, based on a cross-sectional screening study of 73,451 veterans 50-79 years old
1,031 (1%) had AAA > 4 cm on ultrasound
smoking increased risk almost 6x, risk increased with duration and smoking and decreased with duration of quitting
other risk factors included older age, family history, atherosclerosis, hypertension, high cholesterol
Reference - Ann Intern Med 1997 Mar 15;126(6):441 in J Watch 1997 Apr 15;17(8):63
risk factors for AAA include smoking, older age, family history of AAA, atherosclerotic diseases, male sex; while diabetes and black race negatively associated with AAA
52,745 veterans ages 50-79 years without history of AAA underwent successful ultrasound screening for AAA
AAA > 4 cm detected in 613 (1.2%), results consistent with 1.4% detection rate in earlier cohort of 73,451 veterans
odds ratios for major associations with AAA for combined cohorts (total population of 126,196) were
5.07 for smoking
1.94 for family history of AAA
1.71 for age (per 7 years)
1.66 for atherosclerotic diseases;
0.53 for black race
0.52 for diabetes
0.18 for female sex
excess prevalence associated with smoking accounted for 75% of all AAAs > 4 cm
Reference - Arch Intern Med 2000 May 22;160(10):1425 classic risk factors for atherosclerotic diseases associated with AAA
based on a cohort of 29,133 Finnish male smokers, aged 50-69 years
mean follow-up 5.8 years
risk of AAA associated with
age (relative risk 4.56, 95% CI 2.42-8.61 for > 65 vs. 55 years)
smoking years (relative risk 2.25, 95% CI 1.33-3.81 for > 40 vs. 32 years)
systolic blood pressure (relative risk 1.92, 95% CI 1.13-3.25 for > 160 vs. 130 mmHg)
diastolic blood pressure (relative risk 1.8, 95% CI 1.05-3.08 for > 100 vs. 85 mmHg)
serum total cholesterol (relative risk 1.85, 95% CI 1.09-3.12 for > 6.5 vs. 5 mmol/L [> 250 mg/dL vs. 193 mg/dL])
Reference - Epidemiology 2001 Jan;12(1):94 smoking, male sex and hypertension are risk factors for AAA
based on cohort of 5,356 men and women aged 65-79 years participating in randomized trial
current hypertension associated with 30-40% increased risk of AAA while use of antihypertensive medication associated with 70-80% increased risk
men were nearly 6x more likely to develop AAA than women
smoking was an independent risk factor for AAA, with level of exposure more significant than duration
Reference - Br J Surg 2000 Feb;87(2):195 clinical vascular disease strongly associated with AAA
based on prospective study of 4,741 patients > 64 years old
ratio of transverse diameter of maximum infrarenal aorta and aorta just below superior mesenteric artery, defined as I/S ratio; AAA defined as I/S ratio 1.2
overall incidence of AAA 9.5%, with 14.2% in men and 6.2% in women
risk factors for AAA include age, male sex, coronary artery disease, peripheral vascular disease, carotid occlusive disease, smoking and elevated LDL levels
no relationship found between blood pressure and presence of AAA, although patients treated for hypertension more likely to have AAA
Reference - Arterioscler Thromb Vasc Biol 1996 Aug;16(8):963 in QuickScan Reviews in Fam Pract 1997 Feb;21(11):11
family history associated with increased risk, especially for older male relatives of persons with AAA
study of 214 living relatives > 50 years old of 150 consecutive patients undergoing repair of infrarenal AAA vs. 284 controls
comparing persons with family history of AAA vs. controls
4.6% vs. 1.4% had AAA > 3 cm detected by ultrasound or had prior AAA repair
1.2% vs. 0 had aortic dilatation (2-2.9 cm)
Reference - Ann Intern Med 1999 Apr 20;130(8):637 in J Watch 1999 Jun 1;19(11);87, summary in Am Fam Physician 1999 Sep 15;60(4):1234Complications:
rupture
erosion of adjacent structures
embolization, thrombosis
fistulization, including aortocaval fistula (high-output congestive heart failure)
disseminated intravascular coagulation (DIC) reported in 3% to 4% patients having surgery for AAA
DIC reported in 2 of 67 (3%) patients having surgery for AAA (Ann Vasc Surg 1996 Jul;10(4):396)
DIC reported in 3 of 76 (4%) patients having surgery for AAA (Arch Surg 1983 Nov;118(11):1252)
Associated conditions:
coronary artery disease -- AAA associated with increased incidence of cardiovascular disease and mortality
based on cohort of 4,734 men and women > 65 years old followed for 4.5 years
8.8% had AAA (88% of which had 3-3.5 cm diameter)
comparing persons with vs. without AAA
all-cause mortality 6.51 vs. 3.28 per 100 person-years
cardiovascular mortality 3.43 vs. 1.38 per 100 person-years
incident cardiovascular disease 4.73 vs. 3.1 per 100 person-years
Reference - Ann Intern Med 2001 Feb 6;134(3):182 arterial infection with Salmonella cholerasius or S. typhimurium
iliac artery aneurysm (extension of AAA, pulsatile mass on rectal exam, occasionally ruptures into gastrointestinal tract)
inguinal hernias in men, possibly related to degeneration of connective tissue (Br J Surg 1999 Sep;86(9):1155 in BMJ 1999 Oct 2;319(7214):930)
History
Chief Concern (CC):
usually asymptomatic until rupture
symptoms may include abdominal pain, low back pain, leg ischemia, flank pain, claudication, impotence
rupture may present with acute epigastric and back pain with syncope or shock
History of Present Illness (HPI):
mid-abdominal or flank pain which may radiate to back, groin or scrotum
sudden onset of pain may suggest rupture
Past Medical History (PMH):
hypertension, diabetes mellitus, COPD, coronary artery disease
Family History (FH):
can be familial (X-linked most common, also autosomal dominant), but same groups have atherosclerosis
Social History (SH):
smoking
Physical
General Physical:
normal vital signs may be present initially with rupture, but patients can become severely hypotensive rapidly
Abdomen:
usually presents as asymptomatic palpable pulsatile nontender mass, bruits
abdominal palpation
clinical exam may not be reliable to rule out AAA, especially in obese patients
based on literature review
sensitivity of physical exam ranges from 33% to 100%
specificity ranges from 75% to 100%
positive predictive value ranges from 14% to 100%
Reference - Accid Emerg Nurs 2004 Apr;12(2):99 abdominal palpation technique
patient in supine position with knees raised and abdominal muscles relaxed
aortic pulse palpated just above and to left of umbilicus
width of aorta measured by placing both hands palms down on patient's abdomen, with index fingers on either side of aorta
each systole should move fingers apart
width of aorta more important than intensity of pulsation
ultrasound warranted if aortic diameter > 2.5 cm
Reference - JAMA 1999 Jan 6;281(1):77 in Am Fam Physician 1999 Apr 15;59(8):2343 abdominal palpation for detecting AAA has limited sensitivity and specificity
based on pooled analysis of 15 studies of patients screened for AAA with both abdominal palpation and ultrasound
sensitivity of abdominal palpation was 29% for AAAs 3-3.9 cm, 50% for AAAs 4-4.9 cm and 76% for AAAs > 5 cm diameter
43% positive predictive value for AAA > 3 cm
limited data suggest that abdominal obesity decreases sensitivity
abdominal palpation was only physical exam maneuver demonstrated to be of value in detecting AAA
abdominal palpation appears to be safe and not reported to precipitate rupture
abdominal palpation cannot be relied on to rule out AAA, especially if rupture is a possibility
Reference - JAMA 1999 Jan 6;281(1):77, commentary can be found in JAMA 1999 Jun 2;281(21):1989 abdominal palpation has only moderate sensitivity for detecting AAA
based on study of 2 of 3 internists examining 99 persons ages 51-88 years known to have AAA and 101 persons without AAA on ultrasound
abdominal palpation had 68% sensitivity, 75% specificity, positive likelihood ratio 2.7, and negative likelihood ratio 0.43
77% interobserver pair agreement (kappa = 0.53)
100% sensitivity for the 6 patients with abdominal girth < 100 cm and AAA > 5 cm
Reference - Arch Intern Med 2000 Mar 27;160(6):833, commentary can be found in ACP Journal Club 2001 Jan-Feb;134(1):30
periumbilical ecchymosis (Cullen's sign) and ecchymosis over the flanks (Turner's sign) may occur with any process causing hemoperitoneum and has been reported in patients with hemorrhagic pancreatitis, retroperitoneal hemorrhage, splenic rupture, ruptured ectopic pregnancy, leaking aortic aneurysm, lymphoma, hepatocellular carcinoma and liver metastases (N Engl J Med 1999 Jan 14;340(2):149)
Extremities:
inequality of femoral pulses
signs of peripheral emboli
Diagnosis
Making the diagnosis:
abdominal ultrasound or other imaging
Rule out:
inferior wall myocardial infarction
nephrolithiasis
diverticulitis
pancreatitis
mesenteric ischemia
acute cholecystitis
other causes of acute abdomen
Testing to consider:
ultrasound can define length and diameter of aneurysm
computed tomography (CT) if stable and doubtful diagnosis
magnetic resonance angiography (MRA)
electrocardiography (ECG)
Imaging studies:
AAA may appear as incidental finding on abdominal x-ray (stippled calcifications to left of spine)
ultrasound
B-mode ultrasound most practical, cost-effective for serial size
portable ultrasound in emergency department might improve diagnostic certainty but no reliable evidence for impact on clinical outcomes
systematic review found only 1 case series for abdominal aortic aneurysm
portable ultrasound reported to have 100% sensitivity
estimated positive likelihood ratio 14.6 and negative likelihood ratio 0.06 for abdominal aortic aneurysm
no studies reported mortality rates
no studies reported complication rates, time to diagnosis or time to operative treatment for patients with abdominal aortic aneurysm
Reference - CCOHTA technology report 2006 Mar:63 PDF Finnish Medical Society Duodecim evidence-based guideline on indications and preparation of patient for ultrasonographic examinations can be found at National Guideline Clearinghouse 2007 Mar 19:10478 computed tomography (CT)
CT can detect retroperitoneal rupture
CT may show suprarenal extension and other abdominal abnormalities which may influence aneurysm repair
CT estimates of AAA size are larger than ultrasound estimates
based on an analysis of 334 patients in national endograft trial who had both CT and ultrasound measurements
maximal AAA diameter ranged from 4-8 cm on CT
CT measurements exceeded ultrasound measurements in 95% of cases
average difference 0.94 cm, discrepancy increased as AAA size increased
Reference - J Vasc Surg 2003 Sep;38(3):446 in J Watch Online 2003 Oct 21
angiography useful for patients with hypertension secondary to renal artery stenosis, distal arterial occlusive symptoms, or suspected mesenteric ischemia
review of imaging of AAA can be found in Am Fam Physician 2002 Apr 15;65(8):1565
American College of Radiology (ACR) Appropriateness Criteria for pulsatile abdominal mass can be found in National Guideline Clearinghouse 2006 Mar 20:8293, previous version can be found in Radiology 2000 Jun;215(Suppl):55
American College of Radiology (ACR) Appropriateness Criteria for palpable abdominal mass can be found at National Guideline Clearinghouse 2006 Sep 4:9595
Prognosis
Prognosis:
15-20% show no increase in size, > 80% progressive enlargement, 15-20% grow > 0.5 cm/year
some aneurysms quiescent for months to years then sudden increase
large aneurysms usually grow more rapidly
any aneurysm may rupture, risk increases with size
aneurysms growing > 0.5 cm/6 months tend to rupture
retroperitoneal ruptures may be contained but can blowout at any time
risk of rupture in 5 years - < 4.5 cm 9%, 4.5-7 cm 35%, > 7 cm 75%
risk factors for rupture include larger AAA diameter, female sex, higher mean arterial blood pressure and current smoking
based on ultrasound surveillance of 2,257 patients with 4,102 patient-years of follow-up
103 episodes of AAA rupture
number of ruptures per 100 patient-years was 0.3 for AAAs < 4 cm, 1.5 for AAAs 4-4.9 cm and 6.5 for AAAs 5-5.9 cm
Reference - Ann Surg 1999 Sep;230(3):289 in J Watch 1999 Oct 15;19(20):157 or in Am Fam Physician 2000 Feb 1;61(3):875 aneurysm size is a strong predictor of risk of rupture and based on professional association guidelines
estimated annual risk of AAA rupture
< 4.0 cm (0%)
4.0 to 4.9 cm (0.5% to 5%)
5.0 to 5.9 cm (3% to 15%)
6.0 to 6.9 cm (10% to 20%)
7.0 to 7.9 cm (20% to 40%)
8.0 cm (30% to 50%)
5.5 cm considered best threshold for repair in "average" AAA patients
Reference - American Association for Vascular Surgery and Society for Vascular Surgery guidelines (J Vasc Surg 2003 May;37(5):1106)
AAA > 5-5.5 cm has high rupture rate if untreated (i.e. patients unfit for surgery)
based on 3 cohort studies
prospective study of 476 patients (mean age 73 years) with AAA > 5 cm initially considered unfit for surgery
CT performed every 6 months for mean 4 years
173 eventually had elective surgery
50 (10.5%) had rupture of AAA
annual rupture rate for AAAs 5-5.9 cm were 1% for men and 4% for women
annual rupture rate for AAA 6 cm or larger 14% for men and 22% for women
Reference - J Vasc Surg 2003 Feb;37(2):280 in J Watch Online 2003 Mar 18
study of 198 veterans with AAA at least 5.5 cm who refused or were unfit for elective AAA repair
mean follow-up 1.5 years
112 (57%) died and almost half had autopsy
45 patients (23%) had probable AAA rupture
1-year incidence of probably AAA rupture by diameter was 9.4% for 5.5-5.9 cm, 10.2% for 6-6.9 cm (19.1% for 6.5-6.9 cm) and 32.5% for 7 cm or greater
25.7% AAAs 8 cm or greater ruptured within 6 months
Reference - JAMA 2002 Jun 12;287(22):2968 study of 57 patients (mean age 81) with AAA > 5 cm who were considered unfit for surgery (e.g. cardiovascular disease, poor functional status, malignancy) and followed at least 2 years
estimated 3-year rupture rate was 28% for AAA 5-5.9 cm and 41% for AAA > 6 cm
median survival 18 months with 19 deaths from ruptured AAAs and 31 deaths from other causes
Reference - Br J Surg 1998 Oct;85(10):1382 risk of rupture low for aneurysms < 5 cm and varies with size
study of 176 patients with small AAAs followed with Doppler ultrasound for 8 years
24% patients with AAA < 5 cm underwent elective repair
none of 55 AAAs < 3.5 cm ruptured
5% of 75 AAAs 3.5-4.9 cm ruptured
25% of 46 AAAs > 5 cm ruptured
Reference - N Engl J Med 1989 Oct 12;321(15):1009 in Cortlandt Forum 1997 May;10(5):94,111-6
AAA size at last ultrasound predicts risk of AAA rupture
176 patients (mean age 74) with unruptured AAA followed mean 5 years
82 had elective surgery, 11 had rupture, 97 died of other causes
no AAA < 4 cm on last ultrasound ruptured
rupture risk 1%/year for AAAs 4-5 cm and 11%/year for AAAs 5-6 cm
Reference - Arch Intern Med 1997 Oct 13;157(18):2064 in J Watch 1997 Nov 15;17(22):173
small AAAs typically expand at rate of 1-2 mm/year
based on 2 cohort studies
retrospective study of 1,445 men with AAA 3-3.9 cm on screening ultrasound
790 had at least one follow-up ultrasound during mean follow-up 3.9 years
median rate of AAA expansion was 0.11 cm/year
expansion to 5 cm or greater occurred in 6.7% AAAs (4% those 3-3.4 cm, 14% those 3.5-3.9 cm)
no ruptures reported but completeness of follow-up unclear
authors recommend waiting 3 years for follow-up ultrasound for AAAs 3-3.9 cm
Reference - J Vasc Surg 2002 Apr;35(4):666 in J Watch Online 2002 May 14)
cohort study of 41 patients with AAA of median diameter 3.3 cm (range 2.4-4 cm)
median follow-up 7 years (range 1.4-11.6 years)
median linear expansion rate 2 mm/year (range 0-8.4 mm/year) with higher rate associated with larger AAAs
3 patients (7.3%) had rupture, 13 patients (32%) had repair
59% survival at 10-year follow-up (70% survival in patients without repair or rupture)
Reference - Am J Surg 2002 Jan;183(1):53 in Am Fam Physician 2002 May 15;65(10):2128 risk factors for mortality with repair of non-ruptured AAA may include
age > 75 years
female gender
history of previous myocardial infarction
symptomatic course of AAA
insufficient respiratory function
insufficient renal function
Reference - prospective study of 69 patients who had AAA resection for non-ruptured AAA, 8 (11.6%) died within 30 days after surgery (Current Controlled Trials in Cardiovascular Medicine 2005 Sep 7;6:14)
Glasgow Aneurysm Score predicts postoperative survival after open surgical or endovascular intervention
Glasgow Aneurysm Score (GAS) = age in years plus
7 points if myocardial disease (previous myocardial infarction and/or ongoing angina)
10 points if cerebrovascular disease (any stroke or transient ischemic attack)
14 points if renal disease (history of acute or chronic renal failure, creatinine level > 133 mcmol/L [1.51 mg/dL], and/or creatinine clearance < 50 mL/minute)
original GAS developed based on 500 randomly selected patients treated for AAA in general surgical units in Glasgow hospitals 1980-1990, and also included 17 points if shock (Cardiovasc Surg 1994 Feb;2(1):41)
GAS predicts postoperative mortality after endovascular AAA repair
prospective study of 5,498 patients (median age 73 years) with non-ruptured asymptomatic infrarenal AAA at least 4 cm (median 5.6 cm) who received endovascular self-expanding stent-graft and were followed at least 1 month, median GAS 78.8
155 patients (2.8%) died within 30 days
30-day mortality
1.1% with GAS < 74.4
2.1% with GAS 74.4-83.6
5.3% with GAS > 83.6
Reference - Br J Surg 2006 Feb;93(2):191 GAS appears to predict postoperative morbidity and mortality after elective open AAA repair
based on 3 retrospective studies
GAS predicted morbidity and mortality after elective open AAA repair
retrospective study of 1,911 patients undergoing open AAA repair with outcomes at 30 days
GAS > 76 (vs. < 76) predicted
mortality (9% vs. 3%)
severe complications (31% vs. 15%)
cardiac complications (12% vs. 4%)
intensive care unit stay > 5 days (12% vs. 6%)
Reference - Eur J Vasc Endovasc Surg 2003 Dec;26(6):612 GAS predicted postoperative death, severe postoperative complications, myocardial infarction, and stroke in retrospective study of 403 patients undergoing elective open repair of infrarenal AAA (Br J Surg 2003 Jul;90(7):838)
GAS, Leiden score, modified Leiden score and Vanzetto score each predicted in-hospital mortality in retrospective study of 286 patients undergoing elective infrarenal AAA repair; Eagle risk score less accurate for predicting in-hospital mortality; only modified Leiden score predicted postoperative complications (Eur J Vasc Endovasc Surg 2004 Jul;28(1):52)
poor preoperative lung and renal function are associated with postoperative mortality
based on prospective cohort study
cohort of 820 patients aged 60-80 years who had open surgery in UK Small Aneurysm Trial
5.6% overall postoperative mortality risk
postoperative mortality risk significantly associated with higher serum creatinine (p = 0.002) and lower forced expiratory volume in 1 second (p = 0.003)
postoperative mortality risk significantly associated with older age (p = 0.03, but p = 0.08 after adjusting for creatinine level and lower forced expiratory volume in 1 second)
Reference - Br J Surg 2000 Jun;87(6):742
Treatment
Treatment overview:
no good evidence to support medication as primary treatment to reduce AAA expansion or risk of AAA rupture
surgery
surgery recommended for AAA > 5.5 cm (grade B recommendation [inconsistent or limited evidence]) or symptomatic AAA of any diameter (grade C recommendation [lacking direct evidence])
surgery for AAA < 5.5 cm does not reduce mortality within 5 years (level 1 [likely reliable] evidence) but might improve survival after 5 years (level 2 [mid-level] evidence)
intervention not recommended for asymptomatic infrarenal or juxtrarenal AAA < 5 cm in men or < 4.5 cm in women (grade A recommendation [consistent high-quality evidence]) endovascular aneurysm repair (EVAR)
EVAR has lower perioperative mortality than open repair (level 1 [likely reliable] evidence) but similar all-cause mortality at 2-4 years (level 2 [mid-level] evidence)
EVAR may not improve all-cause mortality in patients unfit for open surgery (level 2 [mid-level] evidence) recommendations for ultrasound screening intervals based on aneurysm diameter vary
if > 4.5 cm, every 3-6 months
if 4-4.5 cm, every 6-12 months
if 3.5-4 cm, every 1-2 years
if < 3.5 cm, every 3 years
reduction of traditional cardiovascular risk factors recommended - see Cardiovascular disease prevention overview
Medications:
propranolol (Inderal) has insufficient evidence to support routine use
propranolol might reduce surgery rate but poorly tolerated (level 2 [mid-level] evidence)
based on randomized trial with non-significant trend
548 patients with asymptomatic AAA 3-5 cm randomized to propranolol (target dose 80-120 mg twice daily) vs. placebo for mean 2.5 years
AAA size measured every 6 months by ultrasound and surgery recommended if 5-5.5 cm
20% propranolol vs. 26% placebo patients had elective AAA surgery (p = 0.11)
38% vs. 21% withdrew due to adverse effects (NNH 4)
no significant difference in 12% vs. 9% overall mortality (p = 0.36)
Reference - J Vasc Surg 2002 Jan;35(1):72 in J Watch 2002 Mar 15;22(6):46
propranolol poorly tolerated and might increase mortality (level 2 [mid-level] evidence)
based on small randomized trial with high dropout rate
54 patients with small AAA diagnosed on screening were randomized to propranolol 40 mg vs. placebo PO twice daily
60% propranolol vs. 25% placebo patients dropped out, mainly due to dyspnea
16.7% propranolol vs. 4.2% placebo patients died (NNH 8)
Reference - Int Angiol 1999 Mar;18(1):52 beta blockers might reduce risk for AAA expansion and rupture (level 2 [mid-level] evidence)
based on retrospective studies
Reference - American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF ACE inhibitors reported to be associated with reduced risk of ruptured AAA (level 3 [lacking direct] evidence)
based on nested case-control study
retrospective study of 15,326 patients > 65 years old admitted to hospital for AAA
3,379 (22%) had ruptured AAA and 11,947 (78%) had intact AAA
ACE inhibitor use reported in 665 (20%) with ruptured AAA vs. 2,761 (23%) with intact AAA (odds ratio 0.82, 95% CI 0.74-0.9)
no statistically significant associations found for beta blockers, calcium channel blockers, alpha blockers, angiotensin receptor blockers or thiazide diuretics
Reference - Lancet 2006 Aug 19;368(9536):659, editorial can be found in Lancet 2006 Aug 19;368(9536):622, commentary can be found in Lancet 2006 Nov 4;368(9547):1571, Am Fam Physician 2006 Nov 15;74(10):1780
DynaMed commentary -- cohort of patients admitted to hospital with AAA may not best reflect cohort of patients with AAA
antichlamydial antibiotics may reduce AAA expansion rate but reduction in clinical outcomes (rupture, surgery) not established (level 3 [lacking direct] evidence)
based on 2 randomized trials too small to demonstrate clinical differences
doxycycline may reduce AAA expansion rate (level 3 [lacking direct] evidence)
based on small randomized trial without clinical outcomes
32 patients with AAA 3-5.5 cm randomized to doxycycline 150 mg vs. placebo daily for 3 months and followed for 18 months
41% doxycycline vs. 7% placebo patients had AAA expansion > 5 mm (NNT 3)
Reference - J Vasc Surg 2001 Oct;34(4):606
doxycycline brand names include Monodox, Vibramycin, Vibra-Tabs, Doryx
roxithromycin may reduce AAA expansion rate but may not affect clinical outcomes (level 3 [lacking direct] evidence)
based on small randomized trial
92 men with AAA 3-4.9 cm diameter were randomized to roxithromycin 300 mg vs. placebo PO once daily for 28 days
AAA size monitored annually by ultrasound, men with AAA > 5 cm referred for surgery
mean follow-up 1.5 years
comparing roxithromycin vs. placebo
mean AAA expansion rate 1.56 vs. 2.75 mm/year (p = 0.02)
33% vs. 47% had AAA expansion rate > 2 mm/year (not significant in crude analysis, statistically significant in logistic regression analysis)
12% vs. 14% referred for surgery (not significant)
Reference - Br J Surg 2001 Aug;88(8):1066, Ugeskr Laeger 2002 Dec 9;164(50):5916
roxithromycin brand names include Surlid, Rulide, Biaxsig, Roxar, Roximycin
Surgery:
Patient selection:
potential indications for AAA repair
ruptured AAA
symptomatic AAA
rapidly expanding aneurysm
asymptomatic aneurysms > 5.5 cm
complicated aneurysms
relative contraindications to AAA repair
short life expectancy
myocardial infarction within 6 months
intractable heart failure
severe angina
severe renal dysfunction
decreased mental acuity
surgery recommended for AAA 5.5 cm or larger to eliminate risk of rupture (grade B recommendation [inconsistent or limited evidence])
based on observational evidence
surgery recommended for infrarenal or juxtarenal AAA 5.5 cm or larger to eliminate risk of rupture (grade B recommendation [inconsistent or limited evidence])
surgery probably indicated for suprarenal or type IV thoracoabdominal aneurysms > 5.5 cm (grade B recommendation [inconsistent or limited evidence])
Reference - American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF surgery for AAA < 5.5 cm does not reduce mortality within 5 years (level 1 [likely reliable] evidence) but might improve survival after 5 years (level 2 [mid-level] evidence)
based on 2 randomized trials with 2,226 patients
surgery does not improve 5-year survival for AAA < 5.5 cm (level 1 [likely reliable] evidence)
based on randomized trial
1,136 patients 50-79 years old with asymptomatic AAA 4-5.4 cm diameter who did not have high surgical risk were randomized to immediate open surgical repair vs. surveillance
surveillance group had ultrasound or CT every 6 months with repair for symptomatic aneurysms or aneurysms > 5.5 cm
mean follow-up 4.9 years (range 3.5-8 years)
comparing surgery vs. surveillance
92.6% vs. 61.6% had aneurysm repair by end of study
25.1% vs. 21.5% overall mortality (not significant)
3% vs. 2.6% death related to AAA (not significant)
0.4 vs. 1.9% rupture of AAA (7 of 11 ruptures in surveillance group resulted in death), rate of AAA rupture was 0.6%/year in surveillance group
survival trends did not favor surgery in any prespecified subgroup
Reference - ADAM trial (N Engl J Med 2002 May 9;346(19):1437), editorial can be found in N Engl J Med 2002 May 9;346(19):1484, commentary can be found in POEMs in J Fam Pract 2002 Aug;51(8):671, N Engl J Med 2002 Oct 3;347(14):1112 (correction can be found in N Engl J Med 2002 Dec 5;347(23):1902)
immediate repair vs. surveillance had no significant differences in most quality of life measures
surgery group had increased rate of impotence after 1 year (p < 0.03)
surgery group had better general health scores (p < 0.0001), particularly in first 2 years after randomization
no significant differences in other quality of life measures
Reference - J Vasc Surg 2003 Oct;38(4):745 surgery of small AAA (4-5.5 cm) associated with short-term mortality risk and small long-term survival benefit at 6-10 years (level 2 [mid-level] evidence)
based on randomized trial with borderline statistical significance
1,090 patients ages 60-76 years with AAA 4-5.4 cm diameter were randomized to early elective surgery vs. surveillance by ultrasound (with repair for symptomatic aneurysms or aneurysms > 5.5 cm or expanding > 1 cm/year)
mean follow-up 8 years (range 6-10 years)
comparing surgery vs. surveillance
5.5% 30-day mortality led to early disadvantage with surgery
survival equivalent at 2, 3, 4 and 6 years
28.2% vs. 28.5% mortality at 6 years
43% vs. 48.2% mortality at end of study (p = 0.05, NNT 20)
restricted mean duration of survival at 9 years was 6.5 vs. 6.7 years (not significant)
92.4% vs. 62% had aneurysm repair by end of study
benefit in early surgery group may be associated with lifestyle changes, especially smoking cessation which was 12.8 times more likely after aneurysm repair
no overall differences in quality of life at 1 year but early surgery group had positive improvement in current health perceptions and less negative change in bodily pain
References - UK Small Aneurysm Trial
N Engl J Med 2002 May 9;346(19):1445, editorial can be found in N Engl J Med 2002 May 9;346(19):1484, summary can be found in Am Fam Physician 2002 Sep 15;66(6):1086, commentary can be found in N Engl J Med 2002 Oct 3;347(14):1112, N Engl J Med 2005 Sep 15;353(11):1181
Lancet 1998 Nov 21;352(9141):1649, 1656, commentary can be found in Lancet 1999 Jan 30;353(9150):407 61% surveillance group eventually had surgery (Evidence-Based Medicine 1999 May/Jun;4(3):88)
Cochrane review on surgery for small AAAs not updated since 1999; systematic review last updated 1999 May 5 (Cochrane Library 1999 Issue 4:CD001835)
surgery recommended for symptomatic AAA of any diameter (grade C recommendation [lacking direct evidence])
based on case series, consensus opinion or standard of care
Reference - American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF intervention not recommended for asymptomatic infrarenal or juxtarenal AAA < 5 cm in men or < 4.5 cm in women (grade A recommendation [consistent high-quality evidence])
based on data derived from multiple randomized trials or meta-analyses
American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDFPerioperative management:
perioperative cardiac management
multiple methods for risk stratification include Eagle's 5-point scale, Revised Cardiac Risk Index, and stress imaging
perioperative maintenance of normothermia reduces rate of postoperative unstable angina (level 1 [likely reliable] evidence) based on randomized trial
regional anesthesia may not be associated with lower cardiovascular risk than general anesthesia in patients having vascular surgery (level 2 [mid-level] evidence) based on 4 randomized trials
perioperative beta blockers may reduce mortality and myocardial infarction risk (level 2 [mid-level] evidence) based mostly on small randomized trials
perioperative metoprolol may be ineffective or less effective than atenolol or bisoprolol (level 2 [mid-level] evidence) perioperative clonidine for 4 days associated with reduced mortality for up to 2 years (level 1 [likely reliable] evidence), based on 1 randomized trial, despite no statistically significant effect on myocardial infarction (level 2 [mid-level] evidence), based on 8 randomized trials
statins might be associated with lower perioperative cardiovascular risk (level 2 [mid-level] evidence) based on randomized trial and systematic review of observational evidence
coronary artery revascularization before major vascular surgery did not affect long-term mortality (level 2 [mid-level] evidence) in 1 randomized trial
preoperative cardiac stress testing for intermediate-risk patients not associated with surgical risk reduction (level 2 [mid-level] evidence) in 1 randomized trial
see Perioperative cardiac management for noncardiac surgery for details
antimicrobial prophylaxis recommended just before surgery with cefazolin (Ancef) 1-2 g IV
alternative for hospitals with frequent methicillin-resistant postoperative wound infections or allergy to cephalosporins is vancomycin (Vancocin) 1 g IV given very slowly to avoid hypotension, diphenhydramine (Benadryl) may also be helpful to avoid hypotension
Reference - Med Lett Drugs Ther 2001 Oct 29;43(1116-1117):92 autologous blood (autotransfusion) might not reduce hospital stay or rate of complications (level 2 [mid-level] evidence)
based on 4 small randomized trials with inconsistent results
autologous transfusion and allogeneic transfusion had no significant differences in hospital stay or rate of complications in randomized trial of 145 patients (Ann Surg 2002 Jan;235(1):145 full-text)
intraoperative autotransfusion did not appear to reduce rate of complications in randomized trial of 100 patients (J Vasc Surg 1999 Jan;29(1):22)
intraoperative autotransfusion (vs. homologous blood transfusion) associated with reduced incidence of postoperative systemic inflammatory response syndrome (23% vs. 49%, p = 0.02, NNT 4) and chest infection (10% vs. 29%, p = 0.049, NNT 6) in randomized trial of 81 patients (Br J Surg 2004 Nov;91(11):1443)
autologous transfusion appeared to reduce length of hospital stay (median 9 vs. 12 days, p < 0.05) in randomized trial of 50 patients (Eur J Vasc Endovasc Surg 1997 Dec;14(6):482, J Vasc Nurs 1997 Dec;15(4):111)
N-acetylcysteine did not significantly protect against renal injury (level 3 [lacking direct] evidence) in randomized placebo-controlled trial of 70 patients with normal preoperative renal function who had abdominal aortic surgery (Anesth Analg 2006 Jun;102(6):1638)
type of fluid used not shown to affect outcomes
based on Cochrane review of 9 trials with 412 patients undergoing abdominal aortic surgery
Reference - systematic review last updated 2000 May 15 (Cochrane Library 2000 Issue 4:CD000991)
pulmonary artery catheterization does NOT improve outcomes in high-risk surgery
based on randomized trial
1,994 high-risk patients > 60 years old scheduled for urgent or elective major surgery were randomized to pulmonary-artery catheter vs. no pulmonary-artery catheter
no differences in overall survival in hospital or at 1-year follow-up
pulmonary-artery catheter use associated with higher rate of pulmonary embolism (8 vs. 0 events, NNH 124)
Reference - N Engl J Med 2003 Jan 2;348(1):5, editorial can be found in N Engl J Med 2003 Jan 2;348(1):66, summary can be found in Am Fam Physician 2003 Apr 15;67(8):1787, commentary can be found in N Engl J Med 2003 May 15;348(20):2035, ACP J Club 2003 Nov-Dec;139(3):66 aortic clamp considerations
minimize aortic clamp time
remove clamp slowly, adjust fluid status
complications of clamp removal - acidosis, hyperkalemia
epidural analgesia provides better pain relief and lower complication rate than systemic opioid-based analgesia after open abdominal aortic surgery (level 1 [likely reliable] evidence)
systematic review of 13 randomized trials comparing epidural analgesia and postoperative systemic opioid-based analgesia in 1,224 adults who had elective open abdominal aortic surgery
adequate allocation concealment used in 6 trials
study assessors blinded in 3 trials
intention-to-treat analysis performed in 7 trials
insufficient evidence to confirm or exclude differences in postoperative mortality (3.6% vs. 4.4%, not statistically significant) based on 11 trials with 1,210 patients
epidural analgesia associated with lower visual analog scale scores for pain
at rest on day 1 (statistically significant) and day 2 (not statistically significant)
on movement at postoperative days 1, 2 and 3 (statistically significant)
epidural analgesia associated with about 20% reduction in duration of tracheal intubation or mechanical ventilation
epidural analgesia associated with significantly lower rates of
overall incidence of cardiovascular complication (21.2% vs. 27.9%, p = 0.03, NNT 15) in 4 trials with 611 patients, but difference no longer significant in meta-analysis using random effects model
myocardial infarction (3.8% vs. 7.5%, p = 0.03, NNT 27) in 7 trials with 851 patients
acute respiratory failure (19.8% vs. 30.7%, p = 0.00004, NNT 10) in 6 trials with 861 patients
gastrointestinal complications (1.2% vs. 3.5%, p = 0.03, NNT 50) in 5 trials with 802 patients
renal insufficiency (12.2% vs. 18.9%, p = 0.01, NNT 15) in 5 trials with 738 patients
Reference - systematic review last updated 2006 May 17 (Cochrane Library 2006 Issue 3:CD005059)
Surgical approaches:
direct synthetic graft replacement of infrarenal AAA is standard of care
alternatives
percutaneous transfemoral placement of intraaortic graft (endovascular stent-graft )
extra-anatomic bypass with aneurysm thrombosis or exclusion (aneurysmectomy)
retroperitoneal incision may be associated fewer complications than transabdominal incision, but evidence inconsistent (level 2 [mid-level] evidence)
based on 3 randomized trials
retroperitoneal incision associated with reduced ICU stay and fewer complications in trial in 145 patients having vascular surgery
145 patients having surgery for AAA (81 patients) or aortoiliac occlusive disease (64 patients) were randomized to retroperitoneal vs. transabdominal incision
retroperitoneal incision associated with statistically significant reductions in
prolonged ileus
small bowel obstruction
overall complications
intensive care unit stay (2.3 vs. 3.5 days)
Reference - J Vasc Surg 1995 Feb;21(2):174 retroperitoneal approach not superior in trial in 100 patients having vascular surgery
100 patients having surgery for AAA (64 patients) or aortoiliac occlusive disease (36 patients) were randomized to retroperitoneal vs. transabdominal incision
no significant differences in mortality, morbidity, length of ICU stay (2 vs. 2 days), or length of hospital stay
retroperitoneal approach associated with significantly more wound problems (bulging, hernias and wound pain)
Reference - Cardiovasc Surg 1997 Feb;5(1):71 retroperitoneal approach associated with reduced hospital stay in trial in 36 patients having AAA repair
36 patients having AAA repair randomized to retroperitoneal vs. transabdominal surgery
comparing retroperitoneal vs. transabdominal surgery
mean time to ambulation 2.6 vs. 4.3 (p = 0.005)
mean duration of hospital stay 10.2 vs. 14.5 days (p < 0.0001)
Reference - J Med Assoc Thai 2005 May;88(5):601 minimal incision aortic surgery associated with shorter hospital stay than conventional transperitoneal surgery (level 2 [mid-level] evidence)
based on 2 small randomized trials
minimal incision aortic surgery also called mini-laparotomy or minimally invasive vascular surgery
72 patients with nonruptured AAA randomized to minimal incision aortic surgery vs. retroperitoneal approach vs. transperitoneal approach
transperitoneal approach associated with longer length of ICU stay and hospital stay than other 2 approaches
Reference - Int Angiol 2005 Sep;24(3):238 34 patients with AAA randomized to minimally invasive vascular surgery vs. conventional open repair
mean time to ambulation 2.1 vs. 4.3 days (p < 0.01)
mean duration of hospital stay 20.7 vs. 33.9 days (p < 0.01)
Reference - J Vasc Surg 2002 Apr;35(4):654Surgical complications:
lower annual hospital volume of AAA repair associated with higher mortality (level 2 [mid-level] evidence)
based on meta-analysis of observational studies
in analysis of 21 studies plus UK Hospital Episode Statistics data with 421,299 elective AAA repairs
9.5% overall mortality rate
annual volume < 43 repairs associated with significantly higher mortality
in analysis of 12 studies plus UK data with 45,796 ruptured AAA repairs
37% overall mortality rate
annual volume < 15 repairs associated with significantly higher mortality
Reference - Br J Surg 2007 Apr;94(4):395 mortality rates for elective AAA < 5% with experience (level 2 [mid-level] evidence)
based on observational study
study of all 2,335 elective open surgical AAA repairs done at all non-federal hospitals in Maryland from 1990-1995
3.5% overall in-hospital mortality rate
mortality increased with age from 2.2% < 65 years to 7.3% > 80 years
mortality 2.5% at hospitals with > 100 operations over the 6 years and 4.2-4.3% at hospitals with lower volumes
mortality 9.9% if surgeons performed only 1 elective AAA repair over the 6 years, 4.9% if 2-9 procedures, 2.8-3.8% if higher volumes
age, hospital volume and surgeon volume were significant predictors for perioperative mortality
Reference - J Vasc Surg 1999 Dec;30(6):985 post-operative renal failure (21% rupture, 2.5% elective), mortality up to 90%
ischemic colitis in 9-16%
suspect if postoperative diarrhea, especially heme-positive
treatment is Hartmann's procedure
replanting inferior mesenteric artery instead of ligating inferior mesenteric artery not associated with statistically significant reduction in risk of ischemic colitis (level 2 [mid-level] evidence) (9% vs. 16%) in randomized trial in 128 patients with patent inferior mesenteric artery having infrarenal aortic aneurysm repair (J Vasc Surg 2006 Apr;43(4):689)
acute leg ischemia in up to 7%, related to clamp injury or emboli
aortic graft infection in 1-4%
bacterial seeding or bacteremia, #1 S. aureus, S. epidermidis
pseudointima has decreased resistance to infection
perioperatively first generation cephalosporin
may present as inflammatory mass or draining sinus in groin, fever, occasionally abdominal discomfort, multiple petechiae distally, aortoenteric fistula
CT, indium-tagged WBC, aortogram, sinogram outlines graft if draining sinus
CT to rule out splenic abscess before replacing vascular graft
prophylactic antibiotics recommended for invasive procedures in patients with aortic graft (similar to patients with valvular heart disease)
spinal cord ischemia rare 0.25%, especially if ruptured
injury to artery of Adamkiewicz left T8-L1 occasionally to L4
classic anterior spinal syndrome - paraplegia, rectal/urinary incontinence, loss of pain/temperature sensations, retention of vibration/proprioception sensations
aortoenteric fistula - any patient with GI bleeding and prosthetic vasc graft in abdomen, esophagogastroduodenoscopy to view distal duodenum
pseudoaneurysm (dilation with disruption of layers of vascular wall)
retrograde ejaculation if sympathetic nerves injured
impotence if no perfusion in hypogastric arteries
Endovascular stent-graft:
FDA recommends using AneuRx Stent Graft only in patients meeting appropriate risk-benefit profile who can be treated according to instructions, based on 1.5% perioperative mortality in analysis of 942 patients (FDA MedWatch 2003 Dec 17)
endovascular aneurysm repair (EVAR) has lower perioperative mortality than open repair (level 1 [likely reliable] evidence) but similar all-cause mortality at 2-4 years (level 2 [mid-level] evidence)
based on 4 randomized trials with ascertainment bias for long-term outcomes
systematic review of 4 randomized trials comparing endovascular repair vs. open repair in 1,532 patients with large AAAs
endovascular repair had lower 30-day mortality (1.6% vs. 4.8%, NNT 32)
endovascular repair had shorter hospital stay (weighted median 6.2 vs. 11.5 days)
outcomes at 2-4 years limited by not attributing deaths to AAA if autopsy not done
comparing endovascular vs. open repair at 2-4 years in 3 trials with 1,473 patients
3% vs. 5.7% AAA-related mortality (p = 0.02, NNT 37)
16.8% vs. 17.6% all-cause mortality (not significant, 95% CI ranges from NNT 24 to NNH 30)
Reference - Ann Intern Med 2007 May 15;146(10):735, editorial can be found in Ann Intern Med 2007 May 15;146(10):749, commentary can be found in Ann Intern Med 2008 Feb 5;148(3):245 systematic review of 2 randomized trials comparing endovascular repair vs. open surgical repair for AAA at least 5.5 cm with follow-up at least 2 years
endovascular repair had lower 30-day mortality (1.6% vs. 4.7%, NNT 33)
endovascular repair had higher rates of postoperative complications and reinterventions
no significant differences in mortality at 2 years or quality of life after 3-6 months
Reference - AHRQ Evidence Report on Abdominal Aortic Aneurysm, Endovascular and Open Surgical Repairs 2006 Aug:144 EVAR trial 1
1,082 patients > 60 years old with AAA at least 5.5 cm randomized to endovascular vs. open AAA repair
1,017 patients (94%) complied with allocated treatment
comparing endovascular vs. open AAA repair at 30 days
1.7% vs. 4.7% mortality (p = 0.009, NNT 34)
9.8% vs. 5.8% rate of secondary interventions (p = 0.02, NNH 25)
Reference - EVAR 1 trial (Lancet 2004 Sep 4;364(9437):843), editorial can be found in Lancet 2004 Sep 4-10;364(9437):818; commentary can be found in Am Fam Physician 2005 Jun 15;71(12):2368
EVAR and open aneurysm repair appear to have similar all-cause mortality at 4 years (level 2 [mid-level] evidence)
follow-up rates were 100% at 1 year, 70% at 2 years, 47% at 3 years and 24% at 4 years
comparing endovascular vs. open AAA repair at 4 years in intent-to-treat analysis (all 1,082 patients)
18.4% vs. 20.2% deaths from any cause (not statistically significant)
3.5% vs. 6.3% aneurysm-related deaths (p = 0.04, NNT 36)
41% vs. 9% postoperative complications (p < 0.0001, NNH 3)
no difference in quality of life after 12 months
Reference - Lancet 2005 Jun 25;365(9478):2179, editorial can be found in Lancet 2005 Jun 25;365(9478):2156, commentary can be found in Lancet 2005 Sep 10;366(9489):890, 890, BMJ 2005 Sep 24;331(7518):644, BMJ 2005 Nov 5;331(7524):1081, Perspect Vasc Surg Endovasc Ther 2006 Mar;18(1):74 DREAM trial
based on randomized trial with inadequate statistical power for mortality outcome
endovascular repair has lower perioperative complication rate than open repair (level 1 [likely reliable] evidence) and possibly lower perioperative mortality (level 2 [mid-level] evidence)
based on randomized trial
351 patients (mean age 70 years) with AAA at least 5 cm randomized to endovascular vs. open AAA repair
6 patients who did not undergo surgery were excluded
comparing endovascular vs. open AAA repair at 30 days
1.2% vs. 4.6% mortality (NNT 30 but not statistically significant, p = 0.1)
4.7% vs. 9.8% combined rate of operative mortality and severe complications (NNH 20 but not statistically significant, p = 0.1)
3.5% vs. 10.9% severe complications (p = 0.01, NNT 14)
2.9% vs. 10.9% pulmonary complications (p = 0.005, NNT 13)
Reference - DREAM trial (N Engl J Med 2004 Oct 14;351(16):1607), editorial can be found in N Engl J Med 2004 Oct 14;351(16):1677 2-year survival rates 89.7% vs. 89.6%
differences in first year based entirely on first 30 days
only 1 aneurysm-related death in each group after hospital discharge
no significant differences in rates of moderate or severe complications
Reference - N Engl J Med 2005 Jun 9;352(23):2398, editorial can be found in N Engl J Med 2005 Jun 9;352(23):2443, commentary can be found in ACP J Club 2005 Nov-Dec;143(3):64 3-year outcomes with endovascular repair in clinical practice similar to DREAM trial
856 patients who had EVAR in prospective EUROSTAR registry compared to 177 patients who had EVAR in DREAM trial
no significant differences at 3 years in survival (86.8% vs. 87.6%) or freedom of secondary procedures (86.9% vs. 85.7%)
Reference - Eur J Vasc Endovasc Surg 2007 Feb;33(2):172 EVAR may not improve all-cause mortality in patients unfit for open surgery (level 2 [mid-level] evidence)
based on randomized trial with high crossover rate
338 patients > 60 years old with aneurysms at least 5.5 cm diameter referred to 31 UK hospitals and considered unfit for major surgery were randomized to EVAR vs. no intervention
aneurysm repair done in 150 of 166 patients assigned to EVAR and 47 of 172 assigned to no intervention (thus reducing apparent benefit of EVAR)
mean follow-up 3.3 years
EVAR group had 30-day mortality of 9% (NNH 11)
control group had rupture rate of 9 per 100 person-years
no significant differences in all-cause mortality (64%), aneurysm-related mortality or quality of life at 4 years
9 of 20 aneurysm-related deaths in EVAR group occurred before EVAR was done (reducing apparent benefit of EVAR)
Reference - EVAR 2 trial (Lancet 2005 Jun 25;365(9478):2187), editorial can be found in Lancet 2005 Jun 25-Jul 1;365(9478):2156, commentary can be found in Lancet 2005 Sep 10;366(9489):890, 890, Perspect Vasc Surg Endovasc Ther 2006 Mar;18(1):76 endovascular repair associated with lower morbidity and mortality than open repair in many observational studies (level 2 [mid-level] evidence)
matched cohort study of Medicare beneficiaries
22,830 patients (mean age 76 years) who had endovascular repair compared with 22,830 patients who had open AAA repair in US in 2001-2004
comparing endovascular vs. open repair
1.2% vs. 4.8% perioperative mortality (p < 0.001)
0.4% vs. 2.5% perioperative mortality in those aged 67-69 years (p < 0.001)
2.7% vs. 11.2% for those 85 years old (p < 0.001)
1.8% vs. 0.5% rupture within 4 years (p < 0.001)
9.7%, vs. 4.1% surgery for laparotomy-related complications within 4 years (p < 0.001)
9% vs. 1.7% reintervention related to AAA within 4 years (p < 0.001) (most reinterventions were minor)
14.2% vs. 8.1% hospitalization without surgery for bowel obstruction or abdominal-wall hernia within 4 years (p < 0.001)
mean hospital stay 3.4 vs. 9.3 days (p < 0.001)
medical complications significantly less likely with endovascular repair included myocardial infarction, pneumonia, acute renal failure, deep vein thrombosis or pulmonary embolism (p < 0.001)
Reference - N Engl J Med 2008 Jan 31;358(5):464 retrospective review
comparing 2,565 patients who had endovascular repair vs. 4,607 patients who had open AAA repair in US in 2001
1.3% vs. 3.8% hospital mortality (p = 0.0001)
18% vs. 29% any complications (p = 0.0001)
median hospital stay 2 vs. 7 days (p = 0.0001)
outcomes not tracked after hospital discharge; outcomes still significant after adjustment for risk factors
Reference - J Vasc 2004 Mar;39(3):491 retrospective review comparing 94 endovascular vs. 261 open repairs at Mayo Clinic 1999-2001 at 30 days
0 vs. 1.1% mortality (not significant)
11% vs. 22% cardiac complications (p = 0.02)
3% vs. 16% pulmonary complications (p = 0.001)
13% vs. 4% graft-related complications (p = 0.002)
Reference - J Vasc 2004 Mar;39(3):497 fewer complications (but similar mortality) in 260 patients having endoluminal graft repair compared to 201 patients having conventional open repair (Ann Surg 2001 Oct;234(4):427 in BMJ 2001 Nov 24;323(7323):1260)
non-randomized industry-sponsored multicenter study
190 patients with infrarenal AAA who had AneuRx stent-graft compared with 60 controls who had open surgical repair
major differences favoring stent-graft
shorter (3 vs. 9 days) mean length of hospital stay
reduced transfusion requirement
reduced 30-day rate (12% vs. 23%) of complications
problems with stent-graft were technical inability to access in 4 patients, 21% internal leaks (most spontaneously sealed by 6 months), migration in 3 patients
no stent-graft patient had ruptured AAA or conversion to open surgery in 1 year of follow-up
Reference - J Vasc Surg 1999 Feb;29(2):292 outcomes in series of patients who had endovascular AAA repair
Click for Details endovascular repair associated with high incidence of late secondary interventions; 18% rate of secondary interventions occurring mean 14 months after initial endograft procedure in study of 1,023 patients followed at least 12 months from the EUROSTAR registry (Br J Surg 2000 Dec;87(12):1666 in JAMA 2001 Apr 4;285(13):1683)
in series of 873 patients followed mean 27 months after EVAR
1.8% mortality at 30 days
estimated freedom from AAA rupture 97.6% at 5 years and 94% at 9 years
risk factors for late AAA rupture were female gender and device-related endoleak
87 (10%) patients had reintervention
cumulative survival 52% at 5 years
Reference - Ann Surg 2006 Sep;244(3):426 in series of 150 patients older than 80 years followed for mean 17 months after endovascular AAA repair, 3.3% perioperative mortality, 15% required additional graft-related interventions (Arch Surg 2004 Mar;139(3):308 in J Watch Online 2004 Apr 2)
mean 16 month follow-up of 239 endovascular graft repairs for nonruptured AAAs, 8.5% 30-day mortality but reduced over time (13.6% prior to 1999, 4.4% after 1999), 36% actuarial 5-year survival but most deaths unrelated to AAAs, 23 patients required secondary procedures (Ann Surg 2001 Sep;234(3):323 in J Watch 2001 Oct 15;21(20):161)
first generation stent grafts associated with high risk of late complications
based on cohort of 1,190 patients in EUROSTAR registry who had endovascular stent-graft with Stentor or Vanguard graft and were followed for up to 8 years
7.1% conversion to open repair
2.4% aneurysm rupture
19.9% all-cause mortality
3% aneurysm-related mortality
48% survival at 8 years free of these events
frequent procedure-related complications were endoleak (13 per 100 patient-years), stenosis/thrombosis (4.6 per 100 patient-years) and stent migration (4.3 per 100 patient-years)
Reference - Arch Surg 2007 Jan;142(1):33 retrospective report of first 100 patients treated with endovascular repair at Mayo Clinic can be found in Mayo Clin Proc 2003 Oct;78(10):1234 full-text, commentary can be found in Mayo Clin Proc 2004 Apr;79(4):570 PDF endovascular repair associated with shorter hospitalization (level 2 [mid-level] evidence)
based on small randomized trial
40 patients with low surgical risk profile randomized to endovascular vs. open repair
mean duration of hospitalization 4.5 vs. 11.5 days (p = 0.001)
no significant differences in functional autonomy and quality of life measures
Reference - J Vasc Interv Radiol 2005 Aug;16(8):1093 insufficient evidence to recommend emergency endovascular repair for ruptured AAA
based on Cochrane review
systematic review of randomized trials comparing emergency EVAR vs. open surgical repair in patients with confirmed ruptured AAA
no randomized trials identified
Reference - systematic review last updated 2006 Nov 1 (Cochrane Library 2007 Issue 1:CD005261)
emergency EVAR and open repair appear to have similar outcomes in patients with ruptured AAA (level 2 [mid-level] evidence)
based on observational study of 100 patients with ruptured AAA
49 patients treated with emergency EVAR compared to 51 patients treated with open surgery
comparing emergency EVAR vs. open repair
35% vs. 39% in-hospital or 30-day mortality (not statistically significant)
40% vs. 42% all-cause mortality at 3 months (not statistically significantly)
59% primary complication rate in both groups at 3 months
Reference - J Vasc Surg 2006 Jun;43(6):1111 review of endovascular repair of AAA can be found in N Engl J Med 2008 Jan 31;358(5):494
review of endovascular repair of AAA can be found in Mayo Clin Proc 1999 Oct;74(10):999
discussion of endovascular repair with stent graft can be found in Postgrad Med 2001 Jun;109(6):93
National Institute for Health and Clinical Excellence (NICE) guidance on stent-graft placement in abdominal aortic aneurysm can be found in NICE 2006 Mar:IPG163
Canadian Society for Vascular Surgery consensus statement on endovascular aneurysm repair can be found in CMAJ 2005 Mar 29;172(7):867Follow-up:
small aneurysms (4-5.5 cm) should be followed conservatively
recommendations for ultrasound (or CT) screening intervals based on aneurysm diameter vary
recommended follow-up (ultrasound or CT scan) for infrarenal or juxtarenal AAA
if 4-5.4 cm, every 6-12 months
if < 4 cm, every 2-3 years
American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF recommended ultrasound screening intervals based on aneurysm diameter
if > 4.5 cm, every 3 months
if 4.01-4.5 cm, every 12 months
if 3.51-4 cm, every 2 years
if < 3.5 cm, every 3 years
based on limits to restrict probability of breaching 55-mm limit at rescreening to < 1%
based on cohort of 1,743 patients monitored by ultrasound every 3-6 months for changes in AAA diameter for mean follow-up 1.9 years, patients were enrolled in surveillance arm of trial assessing immediate surgery vs. surveillance, mean initial AAA diameter 4.3 cm (range 2.8-8.5 cm) and mean growth rate 2.6 mm/year
strongest predictor of growth rate was baseline diameter, suggesting AAA growth accelerates as aneurysm enlarges
Reference - Circulation 2004 Jul 6;110(1):16 recommended ultrasound screening intervals based on aneurysm diameter
if 3.5-3.9 cm, rescan at 1 year
if 3-3.4 cm, rescan at 3 years
if 2.6-2.9 cm, rescan at 5 years
based on observational study of 1,121 men > 65 years old followed over 12 years
among 625 men with AAA 2.6-2.9 cm, 2.4% exceeded 5.5 cm or required surgery within 5 years, no ruptures
among 330 men with AAA 3-3.4 cm, 2.1% reached 5.5 cm and 2.9% required surgery at 3 years, no ruptures at 3 years
among 166 men with AAA 3.5-3.9 cm, 1.2% exceeded 5.5 cm at 1 year with no ruptures; at 2 years, 10.5% exceeded 5.5 cm and 1.4% ruptured
Reference - Br J Surg 2003 Jul;90(7):821 in JAMA 2003 Sep 10;290(10):1289
long-term surveillance imaging after endovascular repair
recommended to
monitor for endoleak
document shrinkage or stability of excluded aneurysm sac
determine need for further intervention
ultrasound may not be as sensitive as CT angiography for detection of endoleak after endovascular repair (level 2 [mid-level] evidence)
based on 2 cohort studies with inconsistent results
high quality duplex ultrasound scanning comparable to CT angiography in follow-up imaging in 100 consecutive AAA endovascular surgery patients (J Vasc Surg 2000 Dec;32(6):1142)
ultrasound scanning with or without contrast enhancement not as reliable as CT in diagnosing type II endoleak in cohort of 53 patients who had endovascular AAA repair (J Endovasc Ther 2002 Apr;9(2):170)
Prevention and Screening
Screening:
US Preventive Services Task Force recommendations
USPSTF recommends one-time screening for AAA by ultrasonography in men aged 65-75 years who have ever smoked (B recommendation)
USPSTF makes no recommendation for or against screening for AAA in men aged 65-75 years who have never smoked (C recommendation)
USPSTF recommends against routine screening for AAA in women (D recommendation)
Reference - Ann Intern Med 2005 Feb 1;142(3):198, supporting systematic review can be found in Ann Intern Med 2005 Feb 1;142(3):203, summary can be found at National Guideline Clearinghouse 2005 Feb 7:6013 or in Am Fam Physician 2005 Jun 1;71(11):2144, commentary can be found in J Fam Pract 2005 May;54(5):408, ACP J Club 2005 Jul-Aug;143(1):11, Ann Intern Med 2005 Aug 16;143(4):309 ACC/AHA recommends screening for
men > 60 years old with first-degree relatives with AAA (grade B recommendation [inconsistent or limited evidence])
men ages 65-75 years who have ever smoked (grade B recommendation [inconsistent or limited evidence])
Reference - American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) can be found in J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF Medicare will pay for AAA ultrasound screening for men ages 65-75 years who have smoked at least 100 cigarettes in their lifetime, and for persons with family history of AAAs (AAFP News Now 2006 Nov 8, Medicare News Release 2006 Nov 1), commentary can be found in Fam Pract Manag 2007 Apr;14(4):16
screening men > 65 years old reduces AAA mortality (level 1 [likely reliable] evidence)
based on 4 randomized trials
ultrasound screening reduces AAA mortality in men aged 65-79 years (level 1 [likely reliable] evidence)
based on Cochrane review
systematic review of 4 randomized trials comparing screening vs. no screening in 127,891 men and 9,342 women (only 1 trial included women)
comparing screening vs. no screening in men (meta-analysis of 3 trials with 112,937 men)
11.6% vs. 12.3% all-cause mortality in men (not significant), limited by heterogeneity (p = 0.004)
0.16% vs. 0.27% death from AAA (p = 0.0001, NNT 909)
comparing screening vs. no screening in women (1 trial with 9,342 women)
10.7% vs. 10.2% all-cause mortality in women (not significant)
0.085% vs. 0.043% death from AAA (not significant)
other outcomes comparing screening vs. no screening
0.28% vs. 0.62% ruptured AAA (p = 0.05, NNT 295) in 1 trial with 6,433 men
0.064% vs. 0.043% ruptured AAA (not significant) in 1 trial with 9,342 women
0.89% vs. 0.42% surgery for AAA (p < 0.00001, NNH 212) in 4 trials with 125,595 persons
Reference - systematic review last updated 2007 Jan 26 (Cochrane Library 2007 Issue 2:CD002945), editorial commentary can be found in BMJ 2007 Oct 13;335(7623):732, commentary can be found in BMJ 2007 Nov 3;335(7626):899 ultrasound screening is effective and marginally cost-effective in reducing AAA-related mortality (level 1 [likely reliable] evidence)
based on randomized trial
67,800 men age 65-74 years were randomized to be invited vs. not invited for ultrasound screening
men with abdominal aortic aneurysms 3 cm in diameter or greater were followed with repeat ultrasounds for mean 4.1 years
surgery considered if diameter 5.5 cm or greater, expansion 1 cm per year or greater, or symptoms
27,147 of 33,839 (80%) men invited for screening had ultrasound, 1,333 aneurysms (4.9%) were detected
99% followed up for mortality
comparing invited vs. control group
11.1% vs. 11.4% all-cause mortality (not significant)
0.19% (65 cases) vs. 0.33% (113 cases) aneurysm-related mortality (p = 0.0002, NNT 714)
0.24% (82 cases) vs. 0.41% (140 cases) ruptured AAA (fatal or non-fatal) (NNT 589)
30-day mortality was 6% after elective surgery (24 of 414) and 37% (30 of 81) after emergency surgery
Reference - Multicentre Aneurysm Screening Study (MASS) (Lancet 2002 Nov 16;360(9345):1531), commentary can be found in Lancet 2003 Mar 22;361(9362):1056, POEMs in J Fam Pract 2003 Apr;52(4):272, ACP J Club 2003 May-Jun;138(3):66
ultrasound screening was at margin of acceptability for cost-effectiveness at 4 years, but projected to be more cost-effective at 10 years (BMJ 2002 Nov 16;325(7373):1135), editorial can be found in BMJ 2002 Nov 16;325(7373):1123, commentary can be found in BMJ 2003 Feb 1;326(7383):284, ACP J Club 2003 Jul-Aug;139(1):24
early reduction in AAA-related mortality maintained at 7 years (level 1 [likely reliable] evidence)
based on mean follow-up 7.1 years (range 5.9-8.2 years) of MASS trial
of 67,770 men randomized, 66,328 (97.9%) had follow-up for mortality
comparing invited vs. control group
0.31% (105 cases) vs. 0.58% (196 cases) AAA-related mortality (NNT 371)
0.4% (135 cases) vs. 0.76% (257 cases) ruptured AAA (fatal or non-fatal) (NNT 278)
20.3% vs. 21% all-cause mortality (p = 0.05, NNT 143)
incremental cost-effectiveness ratio at 7 years
$19,500 per life-year gained using AAA-related mortality
$7,600 per life-year gained using all-cause mortality
Reference - Ann Intern Med 2007 May 15;146(10):699, editorial can be found in Ann Intern Med 2007 May 15;146(10):749, commentary can be found in ACP J Club 2007 Nov-Dec;147(3):57 screening all men > 65 years old reduces mortality in Danish population (level 1 [likely reliable] evidence)
based on randomized trial
12,639 Danish men > 65 years old randomized to abdominal ultrasound screening vs. no screening
participants with abdominal aortic aneurysm > 5 cm referred for surgical evaluation, participants with smaller aneurysms offered annual scans
mean follow-up 52 months
among 6,333 men in screening group, 4,860 (76.6%) were screened, 191 of those screened (4%) had abdominal aortic aneurysms
comparing screening vs. no screening
5 vs. 20 patients had emergency operation (NNT 420)
9 vs. 27 death due to AAA (NNT 352)
939 [14.8%] vs. 1,019 [16.2%] overall mortality (NNT 72)
Reference - BMJ 2005 Apr 2;330(7494):750 full-text, commentary can be found in Am Fam Physician 2005 Aug 15;72(4):680, ACP J Club 2005 Sep-Oct;143(2):39 population-based screening may reduce AAA mortality in men aged 65-75 years (level 2 [mid-level] evidence)
based on subgroup analysis of randomized trial
41,000 men aged 65-83 years in western Australia randomized to receive vs. not receive invitation for ultrasound screening
70% of those invited were screened
7.2% had aortic diameter at least 3 cm, 0.5% had aortic diameter at least 5.5 cm
at 5 years, 107 vs. 54 patients had elective AAA surgery (p = 0.002)
18 vs. 25 died from aortic aneurysm (not statistically significant)
difference in death from aortic aneurysm in men aged 65-75 years was statistically significant
Reference - BMJ 2004 Nov 27;329(7477):1259, correction can be found in BMJ 2005 Mar 12;330(7491):596, commentary can be found in BMJ 2005 Mar 12;330(7491):601 offering screening ultrasound to men at age 65 years associated with reduced risk for AAA rupture (level 2 [mid-level] evidence)
based on randomized trial with borderline statistical significance
15,775 patients aged 65-80 years randomized to control vs. invitation for screening ultrasound and followed for up to 5 years
in screening group, patients rescanned annually if aneurysm 3-4.4 cm, rescanned every 3 months if aneurysm 4.5-5.9 cm
surgical criteria were aneurysm > 6 cm, increase in diameter > 1 cm/year, or development of symptoms attributable to aneurysm
of those invited for screening, 68.4% accepted
4% had AAA (7.6% in men, 1.3% in women)
41% of those with AAA satisfied criteria for surgery, and 16% had surgery
none of 31 patients who had elective surgery died within 1 year, whereas 3 of 4 who had emergency surgery died (all 3 had been considered unfit for surgery)
of 2,493 people who declined screening initially, 5 died from ruptured AAA
in control group, 20 men and 2 women presented with ruptured AAA, 19 of whom died within 1 year
comparing screening invitation vs. control in men
16.6% vs. 15.7% overall mortality (not significant)
0.25% vs. 0.5% mortality from AAA rupture (not significant)
0.28% vs. 0.62% incidence of ruptured AAA (NNT 295)
comparing screening invitation vs. control in women
10.7% vs. 10.2% overall mortality (not significant)
0.064% vs. 0.043% mortality from AAA rupture (not significant)
0.064% vs. 0.043% incidence of ruptured AAA (not significant)
Reference - Br J Surg 1995 Aug;82(8):1066, commentary can be found in POEMs in J Fam Pract 1996 Apr;42(4):350 potentially cost-effective approaches to AAA screening for men at age 60-80 years
single screening with abdominal palpation
single screening with ultrasound
repeated screening not cost-effective
Reference - systematic review by Canadian Task Force on the Periodic Health Examination (Ann Intern Med 1993 Sep 1:119(5):411 full-text)
rescreening men with negative initial screen at 4 years reported to have little practical value (level 3 [lacking direct] evidence)
based on large cohort study without long-term follow-up
5,151 veterans aged 50-79 without AAA (defined as > 3 cm) on initial ultrasound randomly selected for rescreening
11.6% had died (not related to AAA)
0.4% had interim diagnosis of AAA
2,622 patients were rescreened and 58 (2.2%) had AAA but most were small (45 were 3-3.5 cm, 10 were 3.5-4 cm, 3 were 4-4.9 cm)
Reference - Arch Intern Med 2000 Apr 24;160(8):1117 review of ultrasound screening can be found in Ann Intern Med 2003 Sep 16;139(6):516, correction can be found in Ann Intern Med 2003 Nov 18;139(10):873, summary can be found in Am Fam Physician 2004 Mar 1;69(5):1247
discussion of evidence for national screening program in United Kingdom can be found in BMJ 2004 May 8;328(7448):1122, editorial can be found in BMJ 2004 May 8;328(7448):1087 (correction can be found in BMJ 2004 Jun 19;328(7454):1486)
References including Reviews and Guidelines
General references used:
American College of Cardiology/American Heart Association (ACC/AHA) 2005 guidelines for peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic) (J Am Coll Cardiol 2006 Mar 21;47(6):1239 PDF)
AHRQ Evidence Report on Abdominal Aortic Aneurysm, Endovascular and Open Surgical Repairs 2006 Aug:144
MEDLINE search 2007 Feb 7 using PubMed Clinical Queries (therapy) for "abdominal aortic aneurysm"
Click for Details Click here to repeat MEDLINE search
40 studies included in this summary
Leurs LJ, Buth J, Harris PL, Blankensteijn JD. Impact of Study Design on Outcome after Endovascular Abdominal Aortic Aneurysm Repair. A Comparison between the Randomized Controlled DREAM-trial and the Observational EUROSTAR-registry. Eur J Vasc Endovasc Surg. 2007 Feb;33(2):172-6.
Rutherford RB. Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomized controlled trial. Perspect Vasc Surg Endovasc Ther. 2006 Mar;18(1):76-7.
Rutherford RB. Endovascular aneurysm repair versus open repair in patients with abdominal aortic aneurysm (EVAR trial 1): randomized controlled trial. Perspect Vasc Surg Endovasc Ther. 2006 Mar;18(1):74-6.
Senekowitsch C, Assadian A, Assadian O, Hartleb H, Ptakovsky H, Hagmuller GW. Replanting the inferior mesentery artery during infrarenal aortic aneurysm repair: influence on postoperative colon ischemia. J Vasc Surg. 2006 Apr;43(4):689-94.
Laohapensang K, Rerkasem K, Chotirosniramit N. Mini-laparotomy for repair of infrarenal abdominal aortic aneurysm. Int Angiol. 2005 Sep;24(3):238-44.
Laohapensang K, Rerkasem K, Chotirosniramit N. Left retroperitoneal versus midline transperitoneal approach for abdominal aortic aneurysms (AAAs) repair. J Med Assoc Thai. 2005 May;88(5):601-6.
Soulez G, Therasse E, Monfared AA, Blair JF, Choiniere M, Elkouri S, Beaudoin N, Giroux MF, Cliche A, Lelorier J, Oliva VL. Pain and quality of life assessment after endovascular versus open repair of abdominal aortic aneurysms in patients at low risk. J Vasc Interv Radiol. 2005 Aug;16(8):1093-100.
EVAR trial participants. Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial. Lancet. 2005 Jun 25-Jul 1;365(9478):2187-92.
EVAR trial participants. Endovascular aneurysm repair versus open repair in patients with abdominal aortic aneurysm (EVAR trial 1): randomised controlled trial. Lancet. 2005 Jun 25-Jul 1;365(9478):2179-86.
Blankensteijn JD, de Jong SE, Prinssen M, van der Ham AC, Buth J, van Sterkenburg SM, Verhagen HJ, Buskens E, Grobbee DE; Dutch Randomized Endovascular Aneurysm Management (DREAM) Trial Group. Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms. N Engl J Med. 2005 Jun 9;352(23):2398-405.
Lindholt JS, Juul S, Fasting H, Henneberg EW. Screening for abdominal aortic aneurysms: single centre randomised controlled trial. BMJ. 2005 Apr 2;330(7494):750.
Mercer KG, Spark JI, Berridge DC, Kent PJ, Scott DJ. Randomized clinical trial of intraoperative autotransfusion in surgery for abdominal aortic aneurysm. Br J Surg. 2004 Nov;91(11):1443-8.
Norman PE, Jamrozik K, Lawrence-Brown MM, Le MT, Spencer CA, Tuohy RJ, Parsons RW, Dickinson JA. Population based randomised controlled trial on impact of screening on mortality from abdominal aortic aneurysm. BMJ. 2004 Nov 27;329(7477):1259.
Prinssen M, Verhoeven EL, Buth J, Cuypers PW, van Sambeek MR, Balm R, Buskens E, Grobbee DE, Blankensteijn JD; Dutch Randomized Endovascular Aneurysm Management (DREAM)Trial Group. A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med. 2004 Oct 14;351(16):1607-18.
Greenhalgh RM, Brown LC, Kwong GP, Powell JT, Thompson SG; EVAR trial participants. Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial. Lancet. 2004 Sep 4-10;364(9437):843-8.
Lederle FA, Johnson GR, Wilson SE, Acher CW, Ballard DJ, Littooy FN, Messina LM; Aneurysm Detection and Management Veterans Affairs Cooperative Study. Quality of life, impotence, and activity level in a randomized trial of immediate repair versus surveillance of small abdominal aortic aneurysm. J Vasc Surg. 2003 Oct;38(4):745-52.
Vammen S, Lindholt JS, Ostergaard LJ, Fasting H, Henneberg EW. [Reduction of the expansion rate of small abdominal aortic aneurysms with roxithromycin. Results from a randomized controlled trial] Ugeskr Laeger. 2002 Dec 9;164(50):5916-9.
Ashton HA, Buxton MJ, Day NE, Kim LG, Marteau TM, Scott RA, Thompson SG, Walker NM; Multicentre Aneurysm Screening Study Group. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet. 2002 Nov 16;360(9345):1531-9.
Multicentre Aneurysm Screening Study Group. Multicentre aneurysm screening study (MASS): cost effectiveness analysis of screening for abdominal aortic aneurysms based on four year results from randomised controlled trial. BMJ. 2002 Nov 16;325(7373):1135.
United Kingdom Small Aneurysm Trial Participants. Long-term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med. 2002 May 9;346(19):1445-52.
Lederle FA, Wilson SE, Johnson GR, Reinke DB, Littooy FN, Acher CW, Ballard DJ, Messina LM, Gordon IL, Chute EP, Krupski WC, Busuttil SJ, Barone GW, Sparks S, Graham LM, Rapp JH, Makaroun MS, Moneta GL, Cambria RA, Makhoul RG, Eton D, Ansel HJ, Freischlag JA, Bandyk D; Aneurysm Detection and Management Veterans Affairs Cooperative Study Group. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med. 2002 May 9;346(19):1437-44.
Matsumoto M, Hata T, Tsushima Y, Hamanaka S, Yoshitaka H, Shinoura S, Sakakibara N. Minimally invasive vascular surgery for repair of infrarenal abdominal aortic aneurysm with iliac involvement. J Vasc Surg. 2002 Apr;35(4):654-60.
Propanolol Aneurysm Trial Investigators. Propranolol for small abdominal aortic aneurysms: results of a randomized trial. J Vasc Surg. 2002 Jan;35(1):72-9.
Wong JC, Torella F, Haynes SL, Dalrymple K, Mortimer AJ, McCollum CN; ATIS Investigators. Autologous versus allogeneic transfusion in aortic surgery: a multicenter randomized clinical trial. Ann Surg. 2002 Jan;235(1):145-51.
Mosorin M, Juvonen J, Biancari F, Satta J, Surcel HM, Leinonen M, Saikku P, Juvonen T. Use of doxycycline to decrease the growth rate of abdominal aortic aneurysms: a randomized, double-blind, placebo-controlled pilot study. J Vasc Surg. 2001 Oct;34(4):606-10.
Vammen S, Lindholt JS, Ostergaard L, Fasting H, Henneberg EW. Randomized double-blind controlled trial of roxithromycin for prevention of abdominal aortic aneurysm expansion. Br J Surg. 2001 Aug;88(8):1066-72.
Tornwall ME, Virtamo J, Haukka JK, Albanes D, Huttunen JK. Life-style factors and risk for abdominal aortic aneurysm in a cohort of Finnish male smokers. Epidemiology. 2001 Jan;12(1):94-100.
Brady AR, Fowkes FG, Greenhalgh RM, Powell JT, Ruckley CV, Thompson SG. Risk factors for postoperative death following elective surgical repair of abdominal aortic aneurysm: results from the UK Small Aneurysm Trial. On behalf of the UK Small Aneurysm Trial participants. Br J Surg. 2000 Jun;87(6):742-9.
Lederle FA, Johnson GR, Wilson SE, Chute EP, Hye RJ, Makaroun MS, Barone GW, Bandyk D, Moneta GL, Makhoul RG. The aneurysm detection and management study screening program: validation cohort and final results. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators. Arch Intern Med. 2000 May 22;160(10):1425-30.
Vardulaki KA, Walker NM, Day NE, Duffy SW, Ashton HA, Scott RA. Quantifying the risks of hypertension, age, sex and smoking in patients with abdominal aortic aneurysm. Br J Surg. 2000 Feb;87(2):195-200.
Brown LC, Powell JT. Risk factors for aneurysm rupture in patients kept under ultrasound surveillance. UK Small Aneurysm Trial Participants. Ann Surg. 1999 Sep;230(3):289-96.
Lindholt JS, Henneberg EW, Juul S, Fasting H. Impaired results of a randomised double blinded clinical trial of propranolol versus placebo on the expansion rate of small abdominal aortic aneurysms. Int Angiol. 1999 Mar;18(1):52-7.
Clagett GP, Valentine RJ, Jackson MR, Mathison C, Kakish HB, Bengtson TD. A randomized trial of intraoperative autotransfusion during aortic surgery. J Vasc Surg. 1999 Jan;29(1):22-30.
[No authors listed] Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants. Lancet. 1998 Nov 21;352(9141):1649-55.
Spark JI, Chetter IC, Kester RC, Scott DJ. Allogeneic versus autologous blood during abdominal aortic aneurysm surgery. Eur J Vasc Endovasc Surg. 1997 Dec;14(6):482-6.
Farrer A, Spark JI, Scott DJ. Autologous blood transfusion: the benefits to the patient undergoing abdominal aortic aneurysm repair. J Vasc Nurs. 1997 Dec;15(4):111-5.
Sieunarine K, Lawrence-Brown MM, Goodman MA. Comparison of transperitoneal and retroperitoneal approaches for infrarenal aortic surgery: early and late results. Cardiovasc Surg. 1997 Feb;5(1):71-6.
Scott RA, Wilson NM, Ashton HA, Kay DN. Influence of screening on the incidence of ruptured abdominal aortic aneurysm: 5-year results of a randomized controlled study. Br J Surg. 1995 Aug;82(8):1066-70.
Sicard GA, Reilly JM, Rubin BG, Thompson RW, Allen BT, Flye MW, Schechtman KB, Young-Beyer P, Weiss C, Anderson CB. Transabdominal versus retroperitoneal incision for abdominal aortic surgery: report of a prospective randomized trial. J Vasc Surg. 1995 Feb;21(2):174-81.
Samy AK, Murray G, MacBain G. Glasgow aneurysm score. Cardiovasc Surg. 1994 Feb;2(1):41-4.
7 studies included in summarized systematic reviews
Norman JG, Fink GW. The effects of epidural anesthesia on the neuroendocrine response to major surgical stress: a randomized prospective trial. Am Surg. 1997 Jan;63(1):75-80.
[No authors listed] The U.K. Small Aneurysm Trial: design, methods and progress. The UK Small Aneurysm Trial participants. Eur J Vasc Endovasc Surg. 1995 Jan;9(1):42-8.
Gold MS, Russo J, Tissot M, Weinhouse G, Riles T. Comparison of hetastarch to albumin for perioperative bleeding in patients undergoing abdominal aortic aneurysm surgery. A prospective, randomized study. Ann Surg. 1990 Apr;211(4):482-5.
Prinssen M, Buskens E, Nolthenius RP, van Sterkenburg SM, Teijink JA, Blankensteijn JD. Sexual dysfunction after conventional and endovascular AAA repair: results of the DREAM trial. J Endovasc Ther. 2004 Dec;11(6):613-20.
Prinssen M, Buskens E, Blankensteijn JD; DREAM trial participants. Quality of life endovascular and open AAA repair. Results of a randomised trial. Eur J Vasc Endovasc Surg. 2004 Feb;27(2):121-7.
Scott RA, Bridgewater SG, Ashton HA. Randomized clinical trial of screening for abdominal aortic aneurysm in women. Br J Surg. 2002 Mar;89(3):283-5.
Scott RA, Vardulaki KA, Walker NM, Day NE, Duffy SW, Ashton HA. The long-term benefits of a single scan for abdominal aortic aneurysm (AAA) at age 65. Eur J Vasc Endovasc Surg. 2001 Jun;21(6):535-40. 166 studies not included in this summary
Hoornweg LL, Wisselink W, Vahl A, Balm R; On behalf of the Amsterdam Acute Aneurysm Trial Collaborators. The Amsterdam Acute Aneurysm Trial: Suitability and Application Rate for Endovascular Repair of Ruptured Abdominal Aortic Aneurysms. Eur J Vasc Endovasc Surg 2007 Jun;33(6):679
Dale W, Hemmerich J, Ghini EA, Schwarze ML. Can induced anxiety from a negative earlier experience influence vascular surgeons' statistical decision-making? A randomized field experiment with an abdominal aortic aneurysm analog. J Am Coll Surg. 2006 Nov;203(5):642-52.
Moore NN, Lapsley M, Norden AG, Firth JD, Gaunt ME, Varty K, Boyle JR. Does N-acetylcysteine prevent contrast-induced nephropathy during endovascular AAA repair? A randomized controlled pilot study. J Endovasc Ther. 2006 Oct;13(5):660-6.
Ward HB, Kelly RF, Thottapurathu
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