Abdominal Aortic Aneurysms

1
Abdominal Aortic Aneurysms

• Aurelia Thibonnier-Calero
• PGY-2
• Vascular Surgery

2
Types of Aneurysms

• True vs. False (pseudoaneurysm)
• True involves all 3 layers of the arterial wall
• False presence of blood flow outside of normal
  layers of arterial wall. Wall of false aneurysm
  is compose of the compressed, surrounding
  tissues.

3
Types of Aneurysms

• Etiology
• Degenerative- complex process that involves some
  degree of calcification, atherosclerotic
  pathology as well as degeneration by MMPs.
• Inflammatory- thick inflammatory wall with
  fibrotic process in retroperitoneum that can
  encase aorta as well as surrounding structures.
  Associated with other inflammatory conditions
  Takayasus, Giant cell arteritis, Polyarteritis
  nodosa, Behcets, Cogans.
• Post-dissection- up to 20 of aneurysms are
  related to previous dissection. Overtime,
  develops into true aneurysm
• Traumatic- false aneurysms
• Developmental Anomalies- persistent sciatic
  arteries, aberrant right subclavian artery.
• Infectious- Can be primary or secondary
  infections.
• Congenital- Tuberous sclerosis, aortic
  coarctation, Marfans.

4
Crawford Aneurysm Type
5
Assessing the AAA patient

• Normal - aorta 1-2.4cm iliac 0.6-1.2cm
• Aneurysm - Aorta gt3cm iliac gt 2cm
• RF for aneurysm
• Older age, male gender, white race, positive
  family history, smoking, HTN, hypercholesterolemia
  , PVD, CAD.
• Ultrasound
• used to diagnose and monitor AAA until aneurysm
  approaches size at which repair considered.
• Computed Tomography
• used in preop assessment of AAA.

6
Ruptured AAA

• No significant overall change in mortality with
  open repair from 1991-2006
• Overall mortality for ruptured AAA 90
• Mortality rate for patients who arrive at
  hosptial alive 40-70
• High postop mortality rate due to MI, renal
  failure, and multi-organ failure
• Ischemia-reperfusion injury, hemorrhagic shock,
  lower torso ischemia
• rEVAR significantly reduces mortality of ruptured
  AAA patients (31 vs 50)

7
Screening for AAA

• US Preventive Services Task Force
• Men 65-75 yo who have ever smoked
• No for or against men 65-75yo who have never
  smoked
• Does not recommend screening for women
• Society of Vascular Surgery, Medicare Screening
• Men who have smoked at least 100 cigarettes
  during their life
• men and women with a family history of AAA
• Only screen patients who are candidates for
  repair.

8
Choosing between Surgery Observation

• Risk for AAA rupture without surgery
• Operative risk of repair
• Patients life expectancy
• Personal preferance of patient

9
1. Risk of Rupture

• Size matters
• Aneurysm gt 5cm 6-16 and gt 7cm 33 annual rupture
  rate
• Wall stress analysis
• Saccular aneurysm have higher rate of rupture
• HTN, COPD, active smoking are independent
  predictors of rupture
• () family hx tend to rupture
• Expansion rate

10
2. Operative Risk of Repair

• Mortality after
• elective open AAA 5
• EVAR 1
• 6 independent RFs for mortality Open repair
• Creatinine gt 1.8, CHF, EKG detected ischemia,
  Pulmonary dysfunction, older age, female gender.
• Cardiac, pulmonary, renal, and GI risks with each
  proceudre.

11
3. Patients Life Expectancy

• Very difficult to assess due to patients
  co-morbidities
• Typical 60yo surviving AAA repair has 13year
  life-expectacy, 70yo has 10year life-expectancy,
  and 80 yo has 6 year life-expectancy.

12
4. Personal Preference of Patient

• Fear of AAA vs. Fear of surgery
• Anecdotal experiences of friends and family
• Procedures provided in community by
  interventional specialists and surgeons.

13
Medical Management of AAA

• Smoking Cessation- Single most important
  modifiable risk factor
• Exercise Therapy- Evidence suggests may benefit
  small aneurysms
• Beta Blockers- May decrease the rate of
  expansion? Important cardiovascular effects thus
  use advocated.
• ACE inhibitors- Evidence is mixed, however,
  implicated in less aneurysm rupture.
• Doxycycline
• Antibiotic activiety against chlamydia species
• Suppresses expression of MMP
• Statins - associated with reduced aneurysm
  expansion rates. Decreases MMP-9 in aneurysm
  wall.

14
EVAR vs. OPEN

• EVAR-1 and DREAM Trials
• Randomized AAA gt 5.5 cm to EVAR vs. open repair
• Lower 30-day mortality for EVAR (1.6 EVAR vs.
  4.6 open)
• Peripop mortality and severe complications 4.7
  EVAR 9.8 open repair (DREAM)
• Similar all-cause mortality at 2 years
• Higher rate of secondary interventions in EVAR
  group
• Total cost of Tx 4 years of f/u is
  significantly increased for EVAR.

15
Open Repair

• Transabdominal Approach
• Previous retroperitoneal surgery
• Ruptured AAA
• Exposure of mid/distal portions of visceral
  vessels or R renal artery
• R internal or external iliac artery
• Co-existant abdominal pathology
• Left-sided vena cava

• Retroperitoneal Approach
• Mult. Previous intraperitoneal procedures
• Abd wall stoma, ectopic/ anomaly of kidney
• Inflammatory aneurysm
• Proximal aortic access, endarterectomy of
  viceral/renal arteries needed
• Obese patients
• Fewer GI complications

16
(No Transcript)
17
Open Repair-Complications

• Cardiac
• Pulmonary
• Renal
• Lower Extremity Ischemia
• Spinal Cord Ischemia
• Incisional Hernia
• 14.2 ventral hernia, 9.7 SBO
• Graft Infection

18
Open Repair ComplicationsColon Ischemia

• Collaterals from SMA, IMA, internal iliac artery,
  and profunda femoris supply sigmoid colon
• Mortality 40-65, full-thickness necrosis 80-100
  
• Occurs in 0.6-3 of elective and 7-27 of
  ruptured AAA (much more common endoscopically
  than clinically)
• Si/Sx persistent acidosis shock, increased
  WBCs and lactate levels, fluid sequestration,
  bloody bowel movements.
• TX
• Ischemia limited to mucosa/submucosa- npo, IVF,
  IV abx
• Transmural ischemia- bowel resection, fecal
  diversion, creation of ostomy, washout of
  abdomen, IV abx.

19
Open Repair- Concomitant Pathology

• Treat the most life-threatening process first
• Avoid simultaneous operations that increase the
  risk for prosthetic graft infection
• If secondary procedure can be staged without
  increased risk - do aneurysm repair first
• Clean procedures (ienephrectomy, oophrectomy)
  can be performed simultaneously with open AAA
  repair
• GI procedures should not occur at same time as
  open repair
• Abort surgery if metastatic disease or abscesses
  which increase risk for graft infection
  discovered.

20
Inflammatory AAA

• Perianeurysmal fibrosis inflammation
• 5 of AAA
• Treatment of AAA resolves the periaortic
  inflammation in 53 (open EVAR)
• Duodenum, left renal vein, and ureters often
  involved in inflammation.
• PreOp ureteral stent placement recommended.

21
Infected AAA

• 0.65 of AAA
• Can be primary or secondary infection
• Potential causes of infection
• Continguous spread of local infxn, septic
  embolization from distal site, bacteremia.
• In the past syphilis and steptococcal species was
  common
• Now staph and salmonella.
• With HIV and wide-spread abx use- can be caused
  by any bacterial or fungal infection
• Dx fever, abdominal/back pain, high ESR,
  bacteremia.

22
EVAR
23
Types of Endoleak
24
Types of Endoleak

• Type I
• Usually identified and treated _at_ time of stent
  graft implantation
• Must be treated if found on post-op imaging
• Associated with high likelihood of AAA rupture
• Bridge with short aortic cuff, Palmaz stent
• Type II
• 10-20 of post-op CT scan show Type II leak
• 80 resolve spontaneously at 6 months
• Indication to treat persistent leak, aneurysm
  growth
• Transcatheter tx (coil embolization)
• Type III
• 0-1.5 incidence
• Strong predictor of rupture
• Tx re-establish continuity by additional
  component to bridge gap or cover hole.
• Type IV
• Majority resolve within one month of stent graft
  implantation

25
EVAR ComplicationsEuroSTAR Registry

• Annual Incidence of Complication (per 1,000
  patients)
• From Van Marrewijk CJ, Leurs LJ, Valabhaneni SR,
  et al. Risk-adjusted outcome analysis of
  endovascular abdominal aortic aneurysm repair. J
  Endovasc Ther. 2005 12 417-429

26
EVAR complications

• Stent-graft infection
• Net infection rate of 0.43
• Pelvic ischemia
• Internal iliac occlusion during EVAR
• Si/sx buttock claudication (most common 16-50),
  buttock necrosis, colon necrosis, spinal
  ischemia, lumbosacral plexus ischemia, ED
  (15-17).
• Ischemic colitis lt 2

27
Long-Term Outcome of Open or Endovascular Repair
of Abdominal Aortic Aneurysm

• De Bruin et al.
• DREAM study group
• The New England Journal of Medicine May 2010

28
Introduction

• Previous studies have shown initial survival
  benefit in patients undergoing EVAR vs. Open
  repair of AAA
• Concern that EVAR is not as durable as AAA and is
  associated with greater risk of rupture and
  secondary interventions.
• Goal Analyze results of Dutch Randomized
  Endovascular Aneurysm Repair (DREAM) study to
  provide long-term data comparing open repair vs.
  EVAR

29
Methods

• Multicenter, randomized, controlled trial
  comparing open repair vs. EVAR in 351 patients
• AAA gt 5cm
• Patients had to be candidates for both techniques
  of repair
• Exclusion Criteria
• Ruptured or inflammatory aneurysms, anatomical
  variations, connective-tissue diseases, hx of
  organ transplant or life-expectancy lt 2 years.
• F/U visits at 30 days, 6/12/18/24months after
  procedure
• After first 2 years, pts received questionnaires
  every 6 months.

30
Methods

• EVAR patient received CT scan annually
• All patients were called at 5 years and invited
  for f/u CT scan.
• Data acquisition stopped Feb 2009
• Primary outcome was rate of death from any cause
  reintervention
• Survival calculated on intention-to-treat basis.

31
Results

• November 2000-December 2003
• 178 patients Open repair vs. 173 EVAR
• Mean age 7yo, 91 male, 43.9 concomittant
  cardiac disease.
• 6 pts did not undergo aneurysm repair
• 4 declined tx, 1 died from rupture, 1 died from
  PNA.
• 8 in hosptial deaths open vs. 2 EVAR
• Mean f/u 6.4 years
• 25 of open patient underwent CT scan at 5 years,
  100 of EVAR

32
Results

• _at_ 6 years post-op
• Survival rate 69.9 open, 68.9 EVAR
• Freedom from reintervention 81.9 open vs. 70.4
  EVAR
• Analysis of causes of death
• EVAR- mostly miscellaneous rather than CV
• Reintervention
• Open repair- majority done for hernia repair
• EVAR- endoleak, endograft migration

33
Discussion

• No significant difference between endovascular
  repair and open repair in rate of overall
  survival at a median of 6.4 years.
• Previously DREAM and EVAR-1 trials demonstrated
  early (2years) survival advantage for EVAR group.
• Significantly higher rate of reinterventions in
  EVAR group than open group
• Study limited by difference in f/u between the
  open and endovascular group.

34
Conclusion

• At 6 years, Open repair and EVAR have similar
  rates of suvival
• EVAR has a greater rate of reintervention

35
Total Percutaneous Access for Endovascular Aortic
Aneurysm Repair (Preclose technique)

• Lee WA, Brown MP, Nelson PR, Huber TS.
• Journal of Vascular Surgery 2007 June
  45(6)1095-101
• University of Florida, Gainesville

36

• large single institutional experience with the
  method and outcomes of a variation of the
  Preclose technique using the 6F Perclose Proglide
  (Abbott Vascular) device during endovascular
  aortic repairs.
• Retrospective review of patient who underwent
  EVAR/TEVAR from Oct 03-Aug06
• 183 perc femoral access with 12-24F Perclose
  technique with Proglide device compared to 154
  patients with open surgical exposure of femoral
  arteries
• Anesthia used for Preclose vs. open general, 49
  vs 55 regional, 45 vs 44 and local, 5 vs 1
  (P .10).
• Percutaneous group broken down into group of
  smaller 12-16F and group of larger 18-24F
  sheaths.
• Data points perioperative outcomes, procedure
  times, operating room usage costs, and technical
  success (in-hospital or 30-day).
• F/U CT scan at 1 month post-op
• The list price for each Perclose Proglide device
  is (US) 295.
• Dilator set 170.44
• cost of the operating room is (US) 3935 for the
  first 60 minutes (not prorated for shorter
  periods) and then 50/min thereafter.

37
Results

• 137 EVAR, 118 TEVAR, 7 iliac repairs performed
• 381 femoral arteries accessed with 12-24F sheaths
• 279 were with 559 Proglide devices using Preclose
  technique in 183 patients
• 4 femoral artereries required 1 device (1.4)
  -all 12F sheaths
• 270 arteries (96.8) required 2 devices
• 5 arteries (1.8) required 3 devices
• 63 of sheaths were gt 18F
• Overall technical success of Preclose technique
  was 94.3
• 99 for smaller sheaths and 91 for larger
  sheaths.

38
Results

• 16 complications
• 13 open repairs of femoral arteries
• 2 emergent placement of covered stent for severe
  retroperitoneal hemorrhage.
• 1 necrotizing arteritis with mycotic
  pseudoaneurysm requiring replacement of femoral
  artery with autogenous femoral vein.
• All cause mortality 2.2
• Access mortality 0

39
Results

• Surgical Group- 154 endovascular repairs
• 108 EVAR and 46 TEVAR
• 258 femoral exposures
• Technical success rate 93.8
• 16 complications
• 10 endarterectomies with patch angioplasty
• 3 wound infections
• 2 infected seromas requiring ID
• 1 severe arteritis requiring debridement and
  replacement of CFA with autogenous femoral vein.
• All cause mortality 1.3
• 0 access-related mortality

40
Results

• Significantly lower OR time for Preclose group
• EVAR 115 vs 128 min
• TEVAR 80 vs 112 min
• Cost OR Proglide vs. OR Surgery
• EVAR 7881 vs 7351
• TEVAR 5679 vs 6556

41
Discussion

• Percutaneous Access
• Shorter procedure time
• Fewer wound complications
• Increased patient comfort
• Limited by size of delivery system.
• In this study
• Smaller sheaths had higher technical success
• All complications occurred intra-op
• No access-related mortality
• Accessing anterior aspect of mid-common femoral
  artery is crucial in preventing hemorrhagic
  complications.

42
Discussion

• Contraindications to Preclose
• Coagulopathy is contra-indication to use of this
  device due to inability to control needle-hole
  bleeding
• Severe calcifications
• Groin scarring
• Obesity
• Previous use of percutaneous closure devices.
• High (suprainguinal ligament) femoral bifurcation
• Need for frequent introducer sheath removals and
  insertions
• Proximal iliac occlusive disease
• Small iliofemoral arteries relative to profile of
  device being used

43
Conclusion

• Prospective, randomized study is needed to truly
  validate this technique
• Percutaneous EVAR is safe and effective
• Long-term data is needed to evaluate effect on
  femoral artery.

44

• The End