1. Mr Andrew Cowan FRCS
Consultant Vascular Surgeon
Royal Devon & Exeter NHS Foundation Trust

2. Anatomy
 From the Greek “to raise or lift”
 General
 Micro
 Macro
 Surface

3. General
 Elastic artery
 Systole
 Inflow > Outflow
Ω

4. General
 Elastic artery
 Systole
 Winkessel Effect
 “air chamber”
 elastic reservoir
 blood store
 potential energy
Ω

5. General
 Elastic artery
 Diastole
 energy released
 Smoothing of pulse
pressure wave
 Common Carotid
 Subclavian
 Pulmonary
Ω

6. Clinical Note
 Atherosclerosis
 Hardening of the wall
 Less distensible
 Raised systolic pulse pressure




Hypertension
CVA
MI
AAA

7. Micro
 3 Layer structure
 Tunica intima
 Tunica media
 Tunica adventitia

Vasa vasorum on outside to nourish

8. Media
 Structurally most important layer
 Elastic lamellae in concentric layers


Smooth muscle
 Not esp active - stiffness
Elastic Matrix
 Dominant layer




Elastin
Collagen
Proteoglycans
Etc…

9. Macro/Surface
 How big…
 2-2.5cm at hiatus
 15-20mm at renals
 Similar at bifurcation
 Size of your thumb

10.  Aorta enters abdomen
 Diaphragmatic hiatus
 2-2.5cm
T12

11.  Inferior phrenic
 Coeliac Trunk
 Hepatic -GDA
 Splenic
 Left Gastric
L1

12.  Inferior phrenic
 Coeliac Trunk
 Hepatic -GDA
 Splenic
 Left Gastric
 Supra renals
 SMA
 Midgut
L1

13.  Inferior phrenic
 Coeliac Trunk
 Hepatic -GDA
 Splenic
 Left Gastric
 Supra renals
 SMA
 Midgut
 Lumbars
 4 paired
 Median sacral
L1

14. Artery of Adamkiewicz
(Great radicular artery of…)
 Typically LEFT posterior intercostal
 75% T8 – L1
 Lower 2/3 cord
 Anterior spinal artery
 BUT
 V occ from LUMBAR arteries

15. Clinical Note
 Occlusion
 Anterior spinal syndrome



Double incontinence
Impaired motor function
Sensation often spared
 EVAR/FEVAR (1-5%)
 Open AAA (thoraco) (1-10%)
 Aortic Dissection
 Coelic plexus block

16.  Gonadals
 Lumbars
 Renal Arteries
 Left renal vein
L2

17. Clinical Note
 Retro Aortic LEFT Renal Vein
 2% of population
 At risk
 Open AAA
 Spinal surgery
 Nutcracker syndrome
 Loin pain
 Haematuria

18.  Lumbars
 IMA
 Hindgut supply
 Sacrificed in AAA




Sacrificed in AAA surgery
? Reimplant
Importance of Int Iliacs
Maintain 2 of 3
L3

19.  Aortic Bifurcation
 ASIS
 Umbilicus
L4

20. Aortic Bifurcation
 Hypogastric plexus
 Iliac surgery
 10% Impotence
 Women ?

21. Iliacs
 Internal
 Buttocks
 Pelvis
 Occlusion
 Buttock claudication
 Erectile impotence
 Distal colonic ischaemia
 Emergency embolistaion


Trauma
Obstetric bleeds

22. Iliacs
 External iliac artery

23. Iliacs
 External iliac artery
 Rectus sheath
haematoma
 Warfarin
 Cough

25. Abdominal Aortic Aneurysm

26. Aims
 Epidemiology
 Pathology
 Aetiology
 Presentation
 Conventional Repair
 Endovascular Repair (EVAR)
 Screening

27. Epidemiology
 Rare <55 years
 (Marfans, Ehlers-Danlos)
 Men 55 - 59 years
 Men >55 years
~5.5%
~9%
 Women 1%
 20% of patients with carotid disease
 3 x more common in patients with inguinal hernia

28. Why repair?
 2% of all post mortem examinations
 7,500 deaths per annum in UK
 5% of sudden deaths in men > 50 yrs
 Mortality from rupture still > 80%
 Locally ~ 13% in hospital
 Vs 25% without cell salvage
 Elective mortality 0.5 - 1.5%

29. Cell Salvage

31. Pathology
 Extracellular matrix contains collagen and elastin
 Not passive dilatation but remodeling
 Elastolysis
 Failure of elastin
 Load on to collagen

32. Pathology
 Infiltration of inflammatory cells into adventitia
 Release of matrix degrading enzymes
 Cigarette smoking
 Premature ageing

33. Microscopic

34. Aetiology
 Age
 Gender

35. Risk of aneurysm death vs age
13
Female
Male
9
7
6
4
1
1
1
60
65
70
1
75
1
80

36. Aetiology
 Age
 Gender
 Genetic
 30% prevalence in first degree male relatives
 Difficult questions...

37. Aetiology
 Age
 Gender
 Genetic
 30% prevalence in first degree male relatives
 Difficult questions...
 Tobacco smoking
 Largest avoidable risk factor

38. Aetiology
 Age
 Gender
 Genetic
 Tobacco smoking
 Hypertension
 COPD
 Occlusive arterial disease

39. Presentation
 Usually asymptomatic - 75%
 urological or colorectal investigation
 Screening programmes
 Symptomatic
 Back or abdominal pain
 Rupture / leak / enlargement
 Vertebral erosion (5%)
 Mimics renal colic

40. Presentation
 Local pressure effects
 Rare
 Duodenal obstruction
 Embolisation

41. Popliteal aneurysm
 10% of AAA pts
 50% are bilateral
 40% chance of AAA
 40% chance of Fem aneurysm
 Thrombosis -50% limb loss

42. When to Repair?
 Symptoms
 Abdominal and back pain
 Radiates loin to groin
 Hypotension and collapse
 Restless

43. 56 year old male
Sudden onset RIF pain to small of back - groin
Sweaty, clammy
Smoker 50/day
P88
BP 105/64
Tender RIF
Obese - No obvious masses
RENAL COLIC

48. Men over 55 years with their FIRST ever episode of renal
colic have ruptured AAA until proven otherwise

49. Fluid Resuscitation
 If talking – BP is adequate as brain is perfused
 Only clamp required
 Fluids increase BP
 Increase bleeding
 Dilute red cells
 Dilute clotting factors
 Increase retroperitoneal swelling

Difficult to close abdomen

50. When to Repair?
 Change in size
 >5mm in 6 months
 (average < 3mm/year)
 Absolute size 5.5cm
 Small Aneurysm Trial
 The Lancet, Volume 353, Issue 9150, Page
408, 30 January 1999
 RAP Scott, Chichester, UK

51. % Yearly Risk of Rupture
30
25
20
15
10
5
0
<3.0
3 - 3.9
4 - 4.9
5 - 5.9
Size (cm)
6 - 6.9
7 - 7.9

52. OPEN REPAIR
vs
ENDOVASCULAR ANEURYSM
REPAIR (EVAR)

53. If severe
comorbidity –
no action –
palliate if
ruptures
Unsuitable for
EVAR
AAA > 5.5cm
Open Repair
after
cardiovascular
work up
Open Repair
after
cardiovascular
work up
CT
Angiogram
Suitable for
EVAR
EVAR

54. Increased myocardial afterload
Limb ischaemia

66. Hypotension
Reperfusion (Lactate etc)
Tachycardia

69. Risks for mortality
Severe angina
Cardiac failure
Diuretic therapy
ECG ischaemia
VEs
Inability to walk 500 yds
Creatinine > 120
Age (per decade)
Vascular Anaesthesia Society
x3
x2
x2
x2
x3
x3
x3
x1.5

70. Complications (%)
 Cardiac






15
Respiratory
10
Renal
5 - 12
DVT
8
Bleeding
2–5
Limb ischaemia 1 – 4
Wound Infection <5
Up to 10%
Erectile Impotence
Less than 1%
 CVA
 Colonic ischaemia
 Cord ischaemia
 Graft infection
 Graft thrombosis

71. Endovascular Repair – EVAR / Stenting
 Juan Parodi - 7th September 1991
 Two groin incisions - “keyhole”
 Woven Dacron
 Nitonol stents (thermal memory)
 “Three stages of innovation”
 Many lessons learned

72. Modular
Bifurcated
Endoluminal Graft
(Cook Zenith)

77. Markers for orientation

79. EVAR Deployment

80. EVAR Suitability
 Approximately 70% for “standard” EVAR
 Neck
 At least 15mm neck
 <34mm diameter
 Parallel sides
 Minimal thrombus
 Minimal calcification
 Not too angulated

81. EVAR Suitability
 Iliac Arteries
 Size
 ~ 7mm
 Tortuosity
 Stiff wires
 Stenoses
 pre dilate
 Calcification
 Caution

82. BUT…….
 Aim of aneurysm repair is
 The isolation of the aneurysm from the circulation
 De-pressurisation of the sac
 Prolonging life by preventing rupture

83. Endoleaks
Persistent or recurrent blood flow
within the aneurysm sac but
outside the stent-graft

84. Endoleaks
 Primary
 Present from initial operation
 40% will seal spontaneously
 Remainder need intervention
 Secondary
 no decline over time

87. Other Failures
 Graft migration
 renal occlusion
 endoleak
 Graft kinking
 limb ischaemia
 Regular follow up therefore essential

88. Follow up
 CT at 3 months
 Yearly USS - sac size
 Yearly AXR- graft integrity
 Sac should get smaller over time
 (Transverse / Longitudinal)

89. Type 2 endoleaks

90. Trials
 EVAR 1
 Fit patients (800)
 EVAR Vs Open
 EVAR 2
 Unfit patients (300)
 EVAR plus best medical management
Vs best medical management

91. EVAR Trials
 1st September 2000
 13 Centres
 Bournemouth, Charing
X, Freeman, Guys, Hull, Leeds, Liverpool, MRI, Norther
n Gen, Queens Nott, UCH, South Manchester.
 Lancet July 2005

92. Fitness for Surgery - 1
 MI within 3 months
 Onset of angina within 3 months
 Unstable angina at night or at rest
 No Intervention Recommended

93. Fitness for Surgery - 2
 Severe valve disease
 Significant arrhythmia
 Uncontrolled CCF
 Unsuitable for open repair

94. Fitness for Surgery - 3
 Open repair not recommended
 FEV1
<1.0 litres
 pO2
<8.0 Kpa
 pCO2
>6.5 Kpa
 Unable to manage stairs without dyspnoea
 Creatinine > 200umol/l

Contrast nephropathy from EVAR

95. EVAR 2
 “EVAR did not improve survival over no intervention…”
 “ongoing need for surveillance and reintervention…”
 “Substantially increased costs…”
 “Improving fitness a priority”

96. EVAR 1 Mortality
RDE EVAR Mortality 0.5% at 30 days

97. BUT…….
 Aim of endovascular repair is
 The isolation of the aneurysm from the circulation
 De-pressurisation of the sac
 Prolonging life by preventing rupture

98. EVAR 1 Complications
RDE EVAR Reinterventions ~2% at 5 years

99. Consultations now more complex
 What to do for younger patient?
 Patients “well informed”
 WWW, Newspapers
 Cost implications
 Devices becoming cheaper
 No ITU stay
 Long follow up
 Who should perform EVAR?

100. Screening for AAA
 Increasing cause of death in over 65s
 Elective mortality 2%%
 Rupture mortality 80%
 Little change despite anaesthetic improvements
 Suggests that mortality could be improved by more
elective operations

101. Gloucester
 Mobile team – portable USS
 Annual visit to GP practice
 Invite each years batch of 65 year old men
 Selected by GP from age/sex register
 Detailed info sheet for patients
 Aortic diameter < 2.6cm reassured and discharged
 Aortic diameter 2.6 – 3.9 rescan at 1 year
 Aortic diameter > 3.9 cm refer to vascular surgeon

102. Summary
 25,000 invitations
 85% attendance
 Approx £10 per scan
 99% imaging success
 1% of aortas > 4cm diameter

103. AAA related mortality for Gloucestershire
50
45
40
35
30
25
65-73
Other
20
15
10
5
0
1994
1995
1996
1997
1998

104. Majority of deaths in 15%
who declined screening

105. BJS July 2001
 1988
 223 men 65 yrs age
 Aorta < 26mm
 USS at 5 and 12 years
 8 lost to FU
 86 died – nil from AAA
 No significant increase in remainder

106. Conclusion
Single normal ultrasound at age 65 effectively rules out
the risk of clinically significant aneurysmal disease

107. Comparison
Screening programme Cost/Life year saved
Breast cancer (UK)
£ 3,044
Breast cancer (NL)
£ 2,440
Cervical cancer (NL)
£ 10,000
Aneurysm screening
£ 795

108. If you were 65 and fit...
EVAR
Open Repair
 2 day stay
 ITU
 0.5% mortality
 7 days
 Rapid recovery
 2% mortality
 Life long follow up
 2 month recovery
 No surveillance required