Abdominal Aortic Aneurysm

1
Abdominal Aortic Aneurysm

• (Infrarenal)
• Management

2
Abdominal Aortic Aneurysm

• End result of a multifactorial process -
  destruction of aortic wall connective tissue
• Surgery (aneurysmorrhaphy)
• Transperitoneal
• Retroperitoneal
• Endoaneurysmorrhaphy
• Exclusion technique

3
Management

• When to treat?
• Balance risk of surgery Vs risk of wait see
• Rate of rupture Aneurysm diameter
• Annual rupture rate
• 0 1 for AAA lt4cm
• 0 12 for AAA lt4.99cm
• 25 for AAA gt5cm

4
Surgery (open)

• Emergency
• Preoperative mortality risk 55
• Perioperative Post operative mortality risk
  27-50
• Elective
• Perioperative mortality 5-7 (1-5)

5
Surgery (open)

• Cardiac complication gt50
• 25 mortality
• Renal 10
• Stroke 7
• Respiratory

6

• Cardiac optimization
• Preoperative cardiac assessment
• Preoperative coronary artery revascularization
• Beta-blockers
• Intensive intraoperative monitoring and
  stabilization
• Pulmonary optimization
• Preoperative lung function assessment
• Chest physiotherapy
• Bronchodilator
• Cease smoking

7
Evolution

• Endovascular / Endoluminal Stenting
• Minimally invasive technique
• Molecular genetics

8
Molecular defect of AAA

• Elastin Interstitial collagens
• Increased enzymes degrading the fibrillar
  extracellular matrix protein
• Matrix metalloproteinases (MMP)
• Plasminogen
• Serine elastases
• Cathepsins

9
Molecular Genetics

• Chronic inflammation prominent feature
• Stimulating factors ? Antigen-driven ?
• Autoimmune disease ?

Montaz W, Timothy B, Rex L C, et al.
Pathogenesis of abdominal aortic aneurysms A
multidisciplinary research program supported by
the National Heart, Lung and Blood Institute. J
of Vascular Surgery Oct 2001 Vol. 34 Number 4
730-738
10
Molecular Genetics

• Anti inflammatory agents
• Doxycycline (Non selective MMP inhibitors)

11
High risk patients

• Pulmonary disease (FEV1 lt 1.0 L)
• Cardiac disease (class IV angina, Ejection
  fraction lt30)
• Chronic renal impairment (creatinine gt 1.8mg/dL)
• Cirrhosis (Child B or C)
• Hostile abdomen
• Obesity (body mass gt 35kg/m2)

12
Morbidity

• Cardiovascular
• Renal
• Pulmonary
• Vascular
• GI tract
• Wound

13
Suitability for Endoluminal Stenting

• Suitability diminished as AAA size increased ?
• No correlation for AAA with lt 7cm size
• Lower proportion of AAA suitable with gt 7cm size

Armo MP, Yusuf SW, Whitaker SC, et al. Influence
of AAA size on the feasibility of endovascular
repair. J Endovasc Surg 19974279-83
14
Endovascular RepairMortality (elective repair)

• 0 to 6 inconsistent
• High risk patients
• Endovascular Tech evolving
• Learning curve
• 0.7
• Blum U, Voshage G, Lammer J et al. Endoluminal
  stentgrafts for infrarenal AAA. N Engl J Med
  1997 33613-20
• 1.1
• Goldstone J, Brewster DC, Chaikof EL, et al.
  Endoluminal repair versus standard open repair of
  AAA early results of a prospective clinical
  comparison trial. Proceedings of the 46th
  Scientific Meeting of The International Society
  for Cardiovascular Surgery 1998 Jun 7-8 San
  Diego, Calif.
• 2
• Zarins CK, White RA, Schwarten DE, et al.
  Medtronic AneuRx Stent Graft System versus open
  surgical repair of AAA Multicenter clinical
  trial. Proceeding of the 46th Scientific Meeting
  of the International Society for Cardiovascular
  Surgery 1998 Jun 7-8 San Diego, Calif.

15
Endoluminal Stenting

• Short Term Failure
• Need for open surgical repair within 1 month
• Long Term Failure
• Need for further endovascular intervention
• Need for explantation
• Need for open surgical repair
• Increased perioperative / postoperative morbidity
  and mortality

Finlayson SR, Birkmeyer JD, Fillinger MF, et al
Should Endovascular surgery lower the threshold
for repair of AAA. Journal of Vascular Surgery
Vol 29(6) June 1999 973-985
16
Long Term Failure Endoluminal Stenting

• Endoleaks persistent
• 4 Types
• Graft Thrombosis
• Graft Migration
• Graft Dysfunction
• Graft Rupture

17
Endoluminal Stenting

• Long Term Durability ?
• Outcome ?

18

• Decrease threshold for Endoluminal Stenting?
• High risk patients
• Low risk patients
• Long term durability?
• Advisable for young patient with small AAA?

19
Current Recommendation

• Minimally Invasive Procedure Vs open
• Clear advantage
• Suitable anatomy
• Higher immediate cost
• Lower perioperative morbidity
• Lower perioperative mortality

William DJ, Jordan MD, Francisco MD et al.
Abdominal Aortic Aneurysm in High Risk Surgical
Patients, comparison of Open and Endovascular
Repair. Annals of Surgery Vol. 237, No 5,
623-630, 2003
20
Current Recommandation

• Elderly high risk patient advantage
• Patient preferences
• Full consent
• Indications
• Endo Vs Open same
• Lack of long term outcomes data
• Await for ongoing clinical trials results
• Goldstone J, Brewster DC, Chaikof EL, et al.
  Endoluminal repair versus standard open repair of
  AAA early results of a prospective clinical
  comparison trial. Proceedings of the 46th
  Scientific Meeting of The International Society
  for Cardiovascular Surgery 1998 Jun 7-8 San
  Diego, Calif.
• Zarins CK, White RA, Schwarten DE, et al.
  Medtronic AneuRx Stent Graft System versus open
  surgical repair of AAA Multicenter clinical
  trial. Proceeding of the 46th Scientific Meeting
  of the International Society for Cardiovascular
  Surgery 1998 Jun 7-8 San Diego, Calif.

21
AAA Management

• Multidisciplinary approach
• Cardiologist
• Surgeon
• Anaesthesiologist
• Intensivist
• Advancement in surgical approach
• Open
• Endovascular
• Basic Pathophysiology Investigation