EndoVascular Aneurysm Repair in the UK: midterm results of (EVAR) trials

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EndoVascular Aneurysm Repair in the UK midterm
results of (EVAR) trials

• Dilip Oswal
• 24.01.2006

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Papers
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EVAR trials
EVAR 1 EVAR 2
Type RCT, pt gt 60 yr RCT, pt gt 60 yr
Duration Sept 99 - Dec 2003 Sept 99 - Dec 2003
Entry criteria AAA gt 5.5 cm AAA gt 5.5 cm
Patients Suitable for EVAR and fit for Sx Unfit for Sx
Comparison Sx v/s EVAR EVAR v/s No intervention
Total patients 1082 338
EVAR number 517/543 146/166
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EVAR 1 recruitment
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EVAR 1 profile
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EVAR 1 outcome
EVAR Surgery
Number of pts 513/543 500/539
All cause mortality 28 28
Aneurysm related deaths 19 34
Deaths from all cause 100 109
Complications 41 9
Mean Hospital costs 13257 9946
HRQL same same
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EVAR 1 cross over

• 15 patients from EVAR group crossed over to open
  repair - why?
• 18 pts from open repair group underwent EVAR -
  why?
• 14 conversions to open repair after EVAR
  deployment four during the primary theatre
  procedure, two more during the primary admission,
  and eight after initial discharge from hospital.

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Other EVAR trials

• Netherlands (DREAM)
• France (ACE)
• USA (OVER)
• DREAM preliminary results - EVAR is not
  associated with an enduring improvement in health
  related quality of life (HRQL) at 12 months.

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Conclusions EVAR 1

• All-cause mortality did not differ between
  patients in EVAR and open repair groups, despite
  an initial postoperative benefit of EVAR.
• Significant difference in the aneurysm-related
  mortality at 4 years (4 vs 7).
• Late complications are much greater after EVAR
  than open repair. Long term surveillance is not
  necessary for open-repair patients, but is
  required after EVAR.
• There is no midterm evidence of all-cause
  mortality or HRQL benefit from EVAR.

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Conclusions EVAR 1

• Midterm results show a 3 aneurysm-related
  survival benefit for EVAR in fit patients, with
  increased need for reinterventions and constant
  surveillance, which increase hospital costs.
• Despite its benefit on 30-day operative mortality
  EVAR cannot, therefore, displace open repair, and
  the skills of open repair should be maintained in
  the training of vascular surgeons.
• Detailed long term cost effectiveness evaluation
  is needed to contribute to guidelines for the use
  of EVAR in routine clinical practice.

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EVAR 2
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EVAR 2 outcome
EVAR BMT No intervention BMT alone

Number 166 172
Aneurysm related deaths 14 19
Deaths from all cause 66 62
All cause mortality same same
Complications 43 18
Mean hospital costs 13632 4983
HRQL same same
BMT Best Medical Treatment, underestimated BMT Best Medical Treatment, underestimated BMT Best Medical Treatment, underestimated
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EVAR 2 results

• No survival benefit (either all-cause or
  aneurysm-related) for EVAR compared with no
  intervention.
• Cross over More than a quarter of patients
  assigned to no intervention for their aneurysm
  underwent aneurysm repair.
• 30 patient preference
• 30 unrecorded reasons, possibly because of
  surgeon preference
• Delay from randomisation to EVAR.

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EVAR 2 conclusions

• EVAR is costly, has little effect on HRQL, and
  involves a continuing need for surveillance and
  reintervention.
• No need to pursue cost-effectiveness modeling in
  EVAR trial 2 at this time.
• Focus should be on improving fitness rather than
  early EVAR.

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Strengths

• Multicentre, UK wide
• Randomised controlled trial
• Adequate numbers
• Comparable patient groups
• Published in a broad based journal

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Issues

• Rapid attrition of the cohort 26-29 62-66
  patients are lost in 4 years in EVAR I II -
  deaths from unrelated causes. No clear idea of
  the true behaviour of the stent graft
• Cross over - results are based on intention to
  treat
• Age - lower limit of 60
• Fitness guideline - subjective bias
• Only 21 out of 41 centres provided costs on
  resource use
• Should also look at learning curve, if the
  results are any better in the later 2 years

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Leeds contribution to EVAR
EVAR I EVAR II
LGI 24 10
SJUH 10 1
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LGI results summary

• 109 patients 1996 2004
• Mean age 74 (51-90) years
• Mean AAA size 6.7 cm
• AAA gt 6 cm 66
• Mean FU 27 months (0-90)
• Procedure related deaths 5 (2 in lt30 d)
• SG explantation 6 all in first 4 yrs
• Endoleak 27 (10 resolved)
• Radiological reintervention 07