Journal Club Presentation 18th of June,2001

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Journal Club Presentation18th of June,2001

• By Ramon Varcoe

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Should we use endoluminal grafting or traditional
open surgery to repair infrarenal AAA?
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Medline Search

• Ovid search engine
• Mesh terms of abdominal aortic aneurysm, blood
  vessel prosthesis and comparative study
• Restricted to studies in English and humans
• 94 matches

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AneuRx stent graft versus open surgical repair of
abdominal aortic aneurysms Multicenter
prospective clinical trial

• By Christopher K. ZARINS et al.
• Stanford,CALIFORNIA

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Background

• Prevalence of AAA
• Open repair has 2-5 mortality with 15 to 30
  morbidity
• Less invasive Endoluminal repair is a more
  attractive option ?

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• 1991 first Endoluminal AAA repair by Parodi
  et.al.
• Medtronic AneuRx stent graft
• Thin walled woven polyester supported by a
  nickel-titanium exoskeleton
• Two parts are pre loaded into delivery sheaths
• Inserted through bilateral femoral arteriotomies
• Fluoroscopic imaging control in angiography suite
  or operating theatre
• Length adjustments can be made with proximal and
  distal extender cuffs

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(No Transcript)
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Study Design

• Prospective
• Controlled
• Multicenter
• Phase I and Phase II studies
• 250 patients
• Not Randomized

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Patient Selection

• Infrarenal AAA Aortic OR Aorto-iliac
• Nonruptured
• Diameter gt5cm OR 4-5cm under certain conditions
• Neck gt10mm long and 18-26 mm diameter
• Iliac A.s lt17mm diameter but able to accommodate
  the delivery catheters

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Exclusion Criteria

• Age lt18 years
• Pregnancy
• CT disease
• Soft tissue infection
• Hypercoaguability
• Traumatic aneurysm
• Life expectancy lt1 yr
• Inability to give informed consent

• Ruptured or leaking aneurysm
• Suprarenal aneurysm
• Thoracic aneurysm
• Inflammatory aneurysm
• Excessive tortuosity of IR neck
• Morbid obesity
• Problems preventing F/U

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Control group

• 60 patients (5 from each centre)
• All fulfilled entry criteria
• Enrolled as matched controls prior to centre
  commencing endovascular procedures

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Follow up evaluation

• Discharge AXR and spiral contrast CT
• 1 month Colour doppler OR contrast CT
• 6 months contrast CT
• 12 months contrast CT

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RESULTS
Surgery (n60) Stent grafting (n190) P value
Procedural success rate 100 97 NS
Anaesthesia time (hours) 4.9 /- 1.8 4.5 /- 1.6 NS
Procedure time (hours) 3.6 /- 1.6 3.1 /- 1.3 NS
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Surgery (n60) Stent Grafting (n190) P Value
Blood loss (ml) 1596 /- 1432 641 /- 636 lt0.001
Patient requiring transfusion 40 12 lt0.001
Time to extubation (days) 0.9 /- 2.3 0.1 /- 0.3 lt0.05
ICU days 2.5 /- 3.1 0.9 /- 1.2 lt0.05
Ambulate without assistance (days) 4.0 /- 4.8 1.5 /- 1.2 lt0.001
Regular diet (days) 5.1 /- 2.5 1.4 /- 0.9 lt0.001
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Mortality

• No significant differences in the 30 day
  postoperative period
• No significant difference in the 1 year follow up
  period

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Morbidity

• Major morbidity - Open gt endoluminal
• Minor morbidity Open NSD endoluminal
• Combined morbidity/mortality rates - Open
  NSD endoluminal

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Morbidity definitions

• MAJOR
• Reoperation
• Secondary endo-procedure
• Myocardial infarction
• Major arrhythmia
• CVA
• Renal failure
• Prolonged hospital stay gt7 or 5 days

• MINOR
• Complicating events that did not prolong the
  hospital stay more than 7 or 5 days

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Endoleaks
Time of evaluation No. of endoleaks
Before discharge 39/185 21
1 month post discharge 16/180 9
6 months post discharge 15/167 9
12 months post discharge 2/33 6
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Length of stay
Surgery (n60) Stent grafting (n190) P value
Length of stay with complications 21 /- 18 9 /- 6 lt0.05
Length of stay without complications 6 /- 2 3 /- 2 lt0.001
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Other outcome measures

• Stent graft migrations (3 patients)
• Surgical conversions (No patients)
• Aneurysm ruptures (No patients)

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Major advantagesto Endoluminal grafting

• Less stressful
• Reduced length of hospital stay
• Reduced major complication rates

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Major disadvantages to Endoluminal grafting

• Morphological unsuitability
• Uncertainty regarding permanence of aneurysm
  exclusion

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Conclusions

• Endoluminal compared favorably to open AAA repair
  (short term success/morbidity)
• The procedure was safe to one year as there were
  no surgical conversions to suggest graft failure
  and no ruptures occurred
• Long term results are not yet available

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Evaluation comments

• Not randomized
• Small sample size in the open surgery group
• Selection bias late in the study
• Short follow up period
• Single prosthesis studied
• Selection criteria for aneurysm morphology
• Two of the authors had a financial interest in
  Medtronic

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Aneurysm rupture after endovascular repair using
the AneuRx stent graft

• By Christopher Zarins etal.
• Completed the phase II and III (1067 patients)
• 13 patients (1) converted to surgical repair
• 9 patients (0.9) ruptured
• 7 of these post-operatively
• All had evidence of poor fixation at one of the
  junctions