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Endovascular repair of abdominal aortic aneurysm

  1. Sharath Chandra Vikram Paravastu1,
  2. Rubaraj Jayarajasingam2,
  3. Rachel Cottam3,
  4. Simon J Palfreyman4,
  5. Jonathan A Michaels5,
  6. Steven M Thomas6,*

Editorial Group: Cochrane Vascular Group

Published Online: 23 JAN 2014

Assessed as up-to-date: 21 JAN 2013

DOI: 10.1002/14651858.CD004178.pub2


How to Cite

Paravastu SCV, Jayarajasingam R, Cottam R, Palfreyman SJ, Michaels JA, Thomas SM. Endovascular repair of abdominal aortic aneurysm. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD004178. DOI: 10.1002/14651858.CD004178.pub2.

Author Information

  1. 1

    The University of Sheffield, Academic Vascular Unit, Sheffield, UK

  2. 2

    Northern General Hospital, Department of Clinical Radiology, Sheffield, South Yorkshire, UK

  3. 3

    Sheffield Teaching Hospital NHS Foundation Trust, Vascular Angiography, Sheffield, South Yorkshire, UK

  4. 4

    Sheffield Teaching Hospitals NHS Foundation Trust, Tissue Viability, Sheffield, UK

  5. 5

    University of Sheffield, ScHARR, School of Health and Related Research, Sheffield, UK

  6. 6

    Northern General Hospital, Sheffield Vascular Institute, Sheffield, UK

*Steven M Thomas, Sheffield Vascular Institute, Northern General Hospital, Herries Road, Sheffield, S5 7AU, UK. s.m.thomas@sheffield.ac.uk.

Publication History

  1. Publication Status: New
  2. Published Online: 23 JAN 2014

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Characteristics of included studies [ordered by study ID]
ACE

MethodsStudy design: Multicentre RCT

Method of randomisation: Stratified by centre

Exclusions post randomisation: 7 (due to withdrawal from consent)

Losses to follow up: 8 (EVAR = 3, OSR = 5)

Intention-to-treat analysis: Yes


ParticipantsCountry: France

Setting: Hospital (25 centres)

Recruitment: 2003 to 2008

Number: 306 (149 OSR, 150 EVAR)

Age: 69 ± 7 years (mean)

Sex: 296 male / 3 female

Inclusion criteria: Consisted of both anatomical criteria and clinical assessment.

- Anatomical criteria (based on CT scan findings):

  • AAA > 5 cm in men (or) > 4.5 cm in women (or) common iliac artery aneurysm > 3.0 cm AND upper neck free of major thrombus or calcification AND ≥ 1.5 cm length AND angle between the neck and the axis of the aneurysm < 60° AND iliac arteries compatible with the introducer sheath


- Clinical assessment:

  • Participants graded as categories 0 to 2 of the comorbidity score of the SVS/AAVS


Exclusion criteria:

  • Previous abdominal aortic surgery
  • Ruptured aneurysm
  • Mycotic aneurysm
  • Severe Iodine allergy
  • Life expectancy deemed < 6 months, (or) category 3 of the SVS/AAVS classification


InterventionsTreatment: EVAR

Control: OSR


OutcomesPrimary: All-cause mortality, major adverse events (myocardial infarction, permanent stroke, permanent haemodialysis, major amputation, paraplegia and bowel infarction)

Secondary: Vascular reinterventions and minor complications


NotesTrial was conducted in individuals considered to be at low-to-medium risk of surgery

Reinterventions for incisional hernia repair were not recorded

In the EVAR group, 4 participants each had surgery under local and epidural anaesthesia. Remainder all had surgery under general anaesthesia


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation done based on centre

Allocation concealment (selection bias)Low riskAllocation only notified < 24 hours

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding of participants and operating surgeons not feasible in such a study

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNo clear data available

Incomplete outcome data (attrition bias)
All outcomes
Low riskPresented results based on intention-to-treat and presented final follow up results. All participants accounted for

Selective reporting (reporting bias)Low riskReported on all predefined outcomes

Other biasLow riskNone identified

DREAM

MethodsStudy design: Multicentre RCT

Method of randomisation: Computer-generated permuted block sequence; in blocks of four

Exclusions post randomisation: 6 participants did not undergo aneurysm repair following randomisation. 4 declined procedure (3 OSR vs 1 EVAR), 1 died from ruptured AAA before repair (OSR) and 1 died from pneumonia (EVAR)

Losses to follow up: None

Intention-to-treat analysis: Yes


ParticipantsCountry: The Netherlands (26 centres) and Belgium (4 centres)

Setting: Hospital

Recruitment: November 2000 to December 2003

Number: 351 (EVAR = 173; OSR = 178)

Age: Mean 70.1 years

Sex: Male:female 10:1

Inclusion criteria: AAA of at least 5 cm in diameter

Exclusion criteria: Participants requiring emergency repair, or participants with inflammatory aneurysms, presence of anatomical variations, connective tissue disease, history of organ transplant, or life expectancy < 2 years


InterventionsTreatment: EVAR

Control: OSR


OutcomesAll-cause mortality; aneurysm-related mortality; complications; reintervention rate


NotesParticipants in both groups were followed up regularly for two years and were subsequently sent questionnaires about health. During year 3 and 4, only EVAR participants had a follow-up visit organised, whereas OSR group participants were advised to see their respective physicians. Five years post randomisation, all participants were contacted by telephone


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Randomization carried out centrally with the use of a computer-generated permuted-block sequence and stratified according to study centre in blocks of four patients."

Allocation concealment (selection bias)Low riskAdequate randomisation technique

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding of participants and operating surgeons not feasible in such a study

Blinding of outcome assessment (detection bias)
All outcomes
Low riskOutcome assessor blinded

Incomplete outcome data (attrition bias)
All outcomes
Low riskAnalysis was intention-to-treat basis

Selective reporting (reporting bias)Low riskReported on all predefined outcomes

Other biasLow riskNone identified

EVAR1

MethodsStudy design: Multicentre RCT

Method of randomisation: Permuted block randomisation

Exclusions post randomisation: 37 participants excluded. 31 died before surgery (EVAR = 12; OSR = 19); 5 refused surgery (all OSR), 2 postponed surgery (EVAR = 1; OSR = 1)

Losses to follow up: 17 (EVAR = 9; OSR = 8)

Intention-to-treat analysis: Yes


ParticipantsCountry: UK

Setting: Hospital (37 centres)

Recruitment: 1 September 1999 to 31 August 2004

Number: 1252 (EVAR = 626; OSR = 626)

Age: Mean (SD) = 74.1 (6.1) years

Sex: Male:female = 10:1

Inclusion criteria: Aged ≥ 60 years with AAA ≥ 5.5 cm in any plane, assessed by CT

Exclusion criteria: Participants unsuitable for EVAR or unfit for operation


InterventionsTreatment: EVAR

Control: OSR


OutcomesPrimary: All-cause mortality

Secondary: Aneurysm-related mortality; incidence of postoperative complications; secondary interventions; HRQoL and hospital costs and durability


NotesResults from this trial were published at different stages of recruitment and follow up. Data for outcomes were taken from the most relevant publication and this is reflected in the total number of participants for some outcomes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Randomisation is performed for each trial using a 50:50 ratio randomly permuted block sizes constructed by the STATA package. Randomisation is stratified by centre and is performed centrally by the trial manager only when all necessary baseline data had been received at the trial co-ordinating centre"

Allocation concealment (selection bias)Low riskAllocation was done only after all baseline data were recorded

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding of participants and operating surgeons not feasible in such a study

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNo clear data available

Incomplete outcome data (attrition bias)
All outcomes
Low riskAnalysis was intention-to-treat basis; all participants accounted for

Selective reporting (reporting bias)Low riskReported on all predefined outcomes

Other biasLow riskNone identified

EVAR2

MethodsStudy design: Multicentre RCT

Method of randomisation: Permuted block randomisation

Exclusions post randomisation: EVAR = 18 (died before undergoing repair)

Within EVAR randomisation group: 7 died, 8 became ineligible, 1 refused surgery and 2 for unknown reasons

Within the no-intervention group: 70 participants had EVAR

Losses to follow up: 1 (no-intervention group)

Intention-to-treat analysis: Yes


ParticipantsCountry: UK

Setting: Hospital (33 centres)

Recruitment: 1 September 1999 to 31 August 2004

Number: 404 (EVAR = 197; no intervention = 207)

Age: Mean (SD) = 76.8 (6.5) years

Sex: Male:female = 6:1

Inclusion criteria: Aged ≥ 60 years with AAA ≥ 5.5 cm, assessed by CT scan and deemed unfit for surgery locally by surgeon, radiologist, anaesthetist and cardiologist

Exclusion criteria: MI within last 3 months, onset of angina within last 3 months, unstable angina at night or at rest


InterventionsTreatment: EVAR

Control: No intervention


OutcomesPrimary: All-cause mortality

Secondary: Aneurysm-related death; HRQoL; postoperative complications; hospital costs


NotesResults from this trial were published at different stages of recruitment and follow up. Data for outcomes were taken from the most relevant publication and this is reflected in the total number of participants for outcomes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Randomisation is performed for each trial using a 50:50 ratio randomly permuted block sizes constructed by the STATA package. Randomisation is stratified by centre and is performed centrally by the trial manager only when all necessary baseline data had been received at the trial co-ordinating centre".

Allocation concealment (selection bias)Low riskAllocation was done only after all baseline data were recorded

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding of participants and operating surgeons not feasible in such a study

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskInformation not clear

Incomplete outcome data (attrition bias)
All outcomes
Low riskAnalysis was intention-to-treat basis; all participants accounted for

Selective reporting (reporting bias)Low riskReported on all predefined outcomes

Other biasLow riskNone identified

OVER

MethodsStudy design: Multicentre RCT

Method of randomisation: permuted block design

Exclusions post randomisation: EVAR = 17 (2 refused, 2 died, 1 repair aborted, 12 had OSR); OSR = 21 (4 refused, 1 died, 3 aborted, 13 had EVAR)

Losses to follow up: 2 (both in EVAR group)

Intention-to-treat analysis: Yes


ParticipantsCountry: USA

Setting: Hospital (42 centres)

Recruitment: 15 October 2002 to 15 October 2008

Numbers: 881 (EVAR = 444; OSR = 437)

Mean age (SD): EVAR = 69.6 years (7.8); OSR = 70.5 years (7.8)

Inclusion criteria:

  • AAA with a maximum external diameter in any plane greater than or equal to 5 cm
  • An iliac aneurysm (associated with an AAA) with a maximum external diameter in any plane greater than or equal to 3 cm
  • AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or equal to 0.7 cm in diameter in 6 months
  • An AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or equal to 1 cm in diameter in 12 months
  • An AAA greater than or equal to 4.5 cm and the AAA is saccular (i.e. a portion of the circumference of the aorta at the level of the aneurysm is considered normal based on CT scan or MRI)
  • An AAA greater than or equal to 4.5 cm and the AAA is associated with distal embolism.as measured from two imaging studies (ultrasound CT scan or MRI) within the appropriate interval, the later one within 6 months of randomisation


Exclusion criteria:

  • Participant has had a previous AAA repair procedure
  • Evidence of AAA rupture by imaging test
  • AAA is not elective (i.e. urgent or emergent operation, usually due to suspected rupture)
  • Likelihood of poor compliance to the protocol
  • Participant refused randomisation
  • Physician refused randomisation


InterventionsTreatment: EVAR

Control: OSR


OutcomesPrimary: Long-term all-cause mortality

Secondary:

1) Procedure failure

2) Short-term major morbidity (i.e. myocardial infarction, stroke, amputation or renal failure requiring dialysis)

3) Inhospital and intensive care unit stay

4) Other complications such as incisional hernia or claudication

5) HRQoL

6) Erectile dysfunction


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was performed by 'permuted block design'

Allocation concealment (selection bias)Low riskAllocation was made only after baseline information was obtained and eligibility verified

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding of participants and operating surgeons not feasible in such a study

Blinding of outcome assessment (detection bias)
All outcomes
Low riskOutcomes were adjudicated by a blinded outcomes assessment committee

Incomplete outcome data (attrition bias)
All outcomes
Low riskAnalysis was intention-to-treat basis; all participants accounted for

Selective reporting (reporting bias)Low riskReported on all predefined outcomes

Other biasLow riskNone identified

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

CAESAR TrialRCT comparing surveillance and selective surgical treatment for abdominal aortic aneurysm less than 5.5 cm in diameter versus early endovascular treatment. Excluded as EVAR was compared with surveillance but not open surgery but trial was not conducted in 'unfit' individuals. In addition the aneurysms were of small diameter.

Cuypers 2001A small RCT comparing cardiac response between EVAR and OSR. The randomisation method and allocation concealment were unclear. Mortality and long-term outcomes were not the primary endpoints. Hence, the trial may not be powered to determine the outcomes considered for this review.

ECAR study 2010RCT comparing EVAR versus OSR in participants with ruptured aorto-iliac aneurysms.

IMPROVE trialRCT comparing EVAR versus OSR in participants with ruptured AAA.

Lottman 2004This study randomised participants in a 3:1 format, where 57 participants were randomised to EVAR and 19 to OSR. Further they present health-related quality of life outcomes estimated at 3 months post surgery. The numbers of participants considered for study, especially in the OSR group, were small and the outcomes were estimated at 3 months only. Therefore, the results may not be a true representative of the effects of the interventions and hence the study was excluded from analysis.

PIVOTAL TrialStudy determined whether repair of small aneurysms is superior to surveillance with respect to the frequency of rupture or aneurysm-related death.

Soulez 2005A small RCT (n = 40), comparing pain and quality of life in participants undergoing EVAR with those undergoing OSR. Randomisation method and allocation concealment were unclear. Mortality and long-term outcomes were not the primary endpoints.

 
Characteristics of ongoing studies [ordered by study ID]
NExT ERA

Trial name or titleNExT ERA: National Expertise Based Trial of Elective Repair of Abdominal Aortic Aneurysms: A Pilot Study

Methods

ParticipantsAll participants with an AAA considered to require non-urgent repair after assessment by one of the participating surgeons will be considered.

InterventionsOpen surgical repair or EVAR treatment of AAA

OutcomesMortality from the time of randomisation until hospital discharge or 30 days after surgery
Non-fatal myocardial infarction
End-organ ischaemic event rates (including renal failure, limb ischaemia, bowel ischaemia, non-fatal stroke)
Reintervention
Quality of life
Success of repair
Mortality at 6 months

Starting dateSeptember 2006

Contact informationTara M Mastracci, MD, FRCSC

NotesNCT00358085: Not yet recruiting, no verification of information since 2006

 
Comparison 1. EVAR versus OSR in the management of fit individuals: all-cause mortality

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Short term mortality (30-day or in-hospital) (excluding participants who died before surgery and those who did not undergo any intervention)42723Odds Ratio (M-H, Fixed, 95% CI)0.33 [0.20, 0.55]

 2 Intermediate mortality (up to 4 years, ITT analysis)42783Odds Ratio (M-H, Fixed, 95% CI)0.92 [0.75, 1.12]

 3 Long term mortality (beyond 4 years, ITT analysis)32484Odds Ratio (M-H, Fixed, 95% CI)0.98 [0.83, 1.15]

 
Comparison 2. EVAR versus OSR in the management of fit individuals: AAA-related mortality

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Intermediate AAA-related mortality (up to four years)42783Odds Ratio (M-H, Random, 95% CI)0.64 [0.29, 1.44]

 2 Long term AAA-related mortality (beyond 4 years)32484Odds Ratio (M-H, Fixed, 95% CI)0.74 [0.50, 1.08]

 
Comparison 3. EVAR versus OSR in the management of fit individuals: reintervention

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Intermediate reintervention (up to four years)32432Odds Ratio (M-H, Random, 95% CI)2.56 [1.04, 6.33]

 2 Long term reintervention (beyond 4 years)32484Odds Ratio (M-H, Random, 95% CI)1.98 [1.12, 3.51]

 
Comparison 4. EVAR versus OSR in the management of fit individuals: endograft-related complications

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Endograft-related complicationsOther dataNo numeric data

 
Analysis 4.1 Comparison 4 EVAR versus OSR in the management of fit individuals: endograft-related complications, Outcome 1 Endograft-related complications.
Endograft-related complications

StudyAny complicationEndoleaksGraft migration

ACE41 (N = 150)(N = 150)

Type I = 10 (7%)

Type II = 31 (21%)
Not reported

DREAM48 (N = 173)(N = 173)

Type I = 12 (7%)

Type II = 8 (5%)
7 (4%)

EVAR1282 (N = 626)(N = 529)

Type I = 27 (5%)

Type II = 79 (15%)

Type III = 8 (1.5%)

Unspecified = 4 (0.75%)
12 (2%)

OVER110 (N = 444)(N = 444)

Overall = 110 (25%)
Not reported

 
Comparison 5. EVAR versus OSR in the management of fit individuals: myocardial complications

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Cardiac related deaths42783Odds Ratio (M-H, Fixed, 95% CI)1.14 [0.86, 1.52]

 
Comparison 6. EVAR versus OSR in the management of fit individuals: stroke

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Non-fatal stroke32432Odds Ratio (M-H, Fixed, 95% CI)0.81 [0.50, 1.31]

 2 Fatal stroke21603Odds Ratio (M-H, Fixed, 95% CI)0.81 [0.42, 1.55]

 
Comparison 7. EVAR versus OSR in the management of fit individuals: pulmonary complications

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Pulmonary complications2650Odds Ratio (M-H, Fixed, 95% CI)0.36 [0.17, 0.75]

 2 Pulmonary related deaths32484Odds Ratio (M-H, Fixed, 95% CI)0.69 [0.45, 1.05]

 
Comparison 8. EVAR versus OSR in the management of fit individuals: renal complications

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Renal complications32152Odds Ratio (M-H, Fixed, 95% CI)1.23 [0.60, 2.55]

 
Comparison 9. EVAR versus OSR in the management of fit individuals: sexual dysfunction

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Erectile dysfunctionOther dataNo numeric data

 
Analysis 9.1 Comparison 9 EVAR versus OSR in the management of fit individuals: sexual dysfunction, Outcome 1 Erectile dysfunction.
Erectile dysfunction

StudyErectile dysfunction measureEVAROSR

ACEBasic assessment -- no questionnaire used7 (4.7%) patients11 (7.4%) patients

OVER5-item International Index of Erectile dysfunction (IIEF)

(Follow up data presented a mean difference from baseline)
Baseline: 11.4 (8.7)

1 year: -2.5 (8.3)

2 years: -3.0 (8.5)
Baseline: 10.3 (8.8)

1 year: -2.3 (7.8)

2 year: -2.9 (8.5)

 
Comparison 10. EVAR versus OSR in the management of fit individuals: health-related quality of life

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Quality of Life using SF-36 and EQ-5DOther dataNo numeric data

 
Analysis 10.1 Comparison 10 EVAR versus OSR in the management of fit individuals: health-related quality of life, Outcome 1 Quality of Life using SF-36 and EQ-5D.
Quality of Life using SF-36 and EQ-5D

StudyQOL

Measure
ComponentsBaseline score EVARBaseline score OSRFollow up scores

EVAR1SF-36Mental Component Score (MCS)

(Mean (SD))
EVAR: 43.59 (6.79)OSR: 43.95 (6.73)EVAR 0-3 months: 43.86 (7.02)

EVAR 3-12 months: 44.64 (6.67)

EVAR 12-24 months: 44.54 (6.43)

OSR 0-3 months: 44.04 (7.31)

OSR 3-12 months: 44.18 (6.81)

OSR 12-24 months: 44.76 (6.81)

EVAR1SF-36Physical Component Score (PCS)

(Mean (SD))
EVAR: 39.92 (5.92)OSR: 39.83 (5.90)EVAR 0-3 months: 37.82 (5.92)

EVAR 3-12 months: 37.77 (5.73)

EVAR 12-24 months: 38.17 (5.83)

OSR 0-3 months: 36.14 (5.45)

OSR 3-12 months: 37.81 (5.84)

OSR 12-24 months: 38.33 (5.78)

EVAR1EQ-5DIndex score

(Mean (SD))
EVAR: 0.75 (0.22)OSR: 0.77 (0.23)EVAR 0-3 months: 0.73 (0.21)

EVAR 3-12 months: 0.71 (0.25)

EVAR 12-24 months: 0.74 (0.24)

OSR 0-3 months: 0.67 (0.25)

OSR 3-12 months: 0.73 (0.23)

OSR 12-24 months: 0.75 (0.25)

OVERSF-36Mental Component Score (MCS)EVAR: 50.6 (10.9)OSR: 51.7 (10.4)EVAR 1 year: -0.77 (10.2)

EVAR 2 years: -0.01 (10.0)

OSR 1 year: -0 (10.0)

OSR 2 years: -0.93 (9.8)

(mean differences from baseline)

OVERSF-36Physical Component Score (PCS)EVAR: 40.5 (10.4)OSR: 40.1 (10.5)EVAR 1 year: -1.2 (9.8)

EVAR 2 years: -2.2 (10.2)

OSR 1 year: -1.2 (10.1)

OSR 2 years: -2.0 (10.8)

(mean differences from baseline)

OVEREQ-5DIndex score

(Mean (SD))
EVAR: 0.79 (0.16)OSR: 0.79 (0.16)EVAR 1 year: -0.02 (0.16)

EVAR 2 years: -0.01 (0.19)

OSR 1 year: -0 (0.17)

OSR 2 years: -0.02 (0.16)

(mean differences from baseline)

 
Comparison 11. EVAR versus OSR in the management of fit individuals: length of hospital stay

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Length of hospital stayOther dataNo numeric data

 
Analysis 11.1 Comparison 11 EVAR versus OSR in the management of fit individuals: length of hospital stay, Outcome 1 Length of hospital stay.
Length of hospital stay

StudyEVAROSRP value

ACE5.8 ± 5.5 days (mean ± SD)10.4 ± 8.3 days (mean ± SD)< 0.0001

DREAM6 days (mean)13 days (mean)< 0.001

EVAR110.3 ± 17.8 days (mean ± SD)15.7 ± 16.9 days (mean ± SD)< 0.001

OVER3.0 days (2.0 to 5.0) (mean/range)7.0 days (6.0 - 10.0) (mean/range)< 0.001