Aaa lecture 14 feb 2013 no pic

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Aaa lecture 14 feb 2013 no pic

  1. 1. Mr Andrew Cowan FRCS Consultant Vascular Surgeon Royal Devon & Exeter NHS Foundation Trust
  2. 2. Anatomy  From the Greek “to raise or lift”  General  Micro  Macro  Surface
  3. 3. General  Elastic artery  Systole  Inflow > Outflow Ω
  4. 4. General  Elastic artery  Systole  Winkessel Effect  “air chamber”  elastic reservoir  blood store  potential energy Ω
  5. 5. General  Elastic artery  Diastole  energy released  Smoothing of pulse pressure wave  Common Carotid  Subclavian  Pulmonary Ω
  6. 6. Clinical Note  Atherosclerosis  Hardening of the wall  Less distensible  Raised systolic pulse pressure     Hypertension CVA MI AAA
  7. 7. Micro  3 Layer structure  Tunica intima  Tunica media  Tunica adventitia  Vasa vasorum on outside to nourish
  8. 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. 9. Macro/Surface  How big…  2-2.5cm at hiatus  15-20mm at renals  Similar at bifurcation  Size of your thumb
  10. 10.  Aorta enters abdomen  Diaphragmatic hiatus  2-2.5cm T12
  11. 11.  Inferior phrenic  Coeliac Trunk  Hepatic -GDA  Splenic  Left Gastric L1
  12. 12.  Inferior phrenic  Coeliac Trunk  Hepatic -GDA  Splenic  Left Gastric  Supra renals  SMA  Midgut L1
  13. 13.  Inferior phrenic  Coeliac Trunk  Hepatic -GDA  Splenic  Left Gastric  Supra renals  SMA  Midgut  Lumbars  4 paired  Median sacral L1
  14. 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. 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. 16.  Gonadals  Lumbars  Renal Arteries  Left renal vein L2
  17. 17. Clinical Note  Retro Aortic LEFT Renal Vein  2% of population  At risk  Open AAA  Spinal surgery  Nutcracker syndrome  Loin pain  Haematuria
  18. 18.  Lumbars  IMA  Hindgut supply  Sacrificed in AAA     Sacrificed in AAA surgery ? Reimplant Importance of Int Iliacs Maintain 2 of 3 L3
  19. 19.  Aortic Bifurcation  ASIS  Umbilicus L4
  20. 20. Aortic Bifurcation  Hypogastric plexus  Iliac surgery  10% Impotence  Women ?
  21. 21. Iliacs  Internal  Buttocks  Pelvis  Occlusion  Buttock claudication  Erectile impotence  Distal colonic ischaemia  Emergency embolistaion   Trauma Obstetric bleeds
  22. 22. Iliacs  External iliac artery
  23. 23. Iliacs  External iliac artery  Rectus sheath haematoma  Warfarin  Cough
  24. 24. Abdominal Aortic Aneurysm
  25. 25. Aims  Epidemiology  Pathology  Aetiology  Presentation  Conventional Repair  Endovascular Repair (EVAR)  Screening
  26. 26. 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
  27. 27. 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%
  28. 28. Cell Salvage
  29. 29. Pathology  Extracellular matrix contains collagen and elastin  Not passive dilatation but remodeling  Elastolysis  Failure of elastin  Load on to collagen
  30. 30. Pathology  Infiltration of inflammatory cells into adventitia  Release of matrix degrading enzymes  Cigarette smoking  Premature ageing
  31. 31. Microscopic
  32. 32. Aetiology  Age  Gender
  33. 33. Risk of aneurysm death vs age 13 Female Male 9 7 6 4 1 1 1 60 65 70 1 75 1 80
  34. 34. Aetiology  Age  Gender  Genetic  30% prevalence in first degree male relatives  Difficult questions...
  35. 35. Aetiology  Age  Gender  Genetic  30% prevalence in first degree male relatives  Difficult questions...  Tobacco smoking  Largest avoidable risk factor
  36. 36. Aetiology  Age  Gender  Genetic  Tobacco smoking  Hypertension  COPD  Occlusive arterial disease
  37. 37. Presentation  Usually asymptomatic - 75%  urological or colorectal investigation  Screening programmes  Symptomatic  Back or abdominal pain  Rupture / leak / enlargement  Vertebral erosion (5%)  Mimics renal colic
  38. 38. Presentation  Local pressure effects  Rare  Duodenal obstruction  Embolisation
  39. 39. Popliteal aneurysm  10% of AAA pts  50% are bilateral  40% chance of AAA  40% chance of Fem aneurysm  Thrombosis -50% limb loss
  40. 40. When to Repair?  Symptoms  Abdominal and back pain  Radiates loin to groin  Hypotension and collapse  Restless
  41. 41. 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
  42. 42. Men over 55 years with their FIRST ever episode of renal colic have ruptured AAA until proven otherwise
  43. 43. 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
  44. 44. 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
  45. 45. % 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
  46. 46. OPEN REPAIR vs ENDOVASCULAR ANEURYSM REPAIR (EVAR)
  47. 47. 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
  48. 48. Increased myocardial afterload Limb ischaemia
  49. 49. Hypotension Reperfusion (Lactate etc) Tachycardia
  50. 50. 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
  51. 51. 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
  52. 52. 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
  53. 53. Modular Bifurcated Endoluminal Graft (Cook Zenith)
  54. 54. Markers for orientation
  55. 55. EVAR Deployment
  56. 56. EVAR Suitability  Approximately 70% for “standard” EVAR  Neck  At least 15mm neck  <34mm diameter  Parallel sides  Minimal thrombus  Minimal calcification  Not too angulated
  57. 57. EVAR Suitability  Iliac Arteries  Size  ~ 7mm  Tortuosity  Stiff wires  Stenoses  pre dilate  Calcification  Caution
  58. 58. BUT…….  Aim of aneurysm repair is  The isolation of the aneurysm from the circulation  De-pressurisation of the sac  Prolonging life by preventing rupture
  59. 59. Endoleaks Persistent or recurrent blood flow within the aneurysm sac but outside the stent-graft
  60. 60. Endoleaks  Primary  Present from initial operation  40% will seal spontaneously  Remainder need intervention  Secondary  no decline over time
  61. 61. Other Failures  Graft migration  renal occlusion  endoleak  Graft kinking  limb ischaemia  Regular follow up therefore essential
  62. 62. Follow up  CT at 3 months  Yearly USS - sac size  Yearly AXR- graft integrity  Sac should get smaller over time  (Transverse / Longitudinal)
  63. 63. Type 2 endoleaks
  64. 64. Trials  EVAR 1  Fit patients (800)  EVAR Vs Open  EVAR 2  Unfit patients (300)  EVAR plus best medical management Vs best medical management
  65. 65. 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
  66. 66. Fitness for Surgery - 1  MI within 3 months  Onset of angina within 3 months  Unstable angina at night or at rest  No Intervention Recommended
  67. 67. Fitness for Surgery - 2  Severe valve disease  Significant arrhythmia  Uncontrolled CCF  Unsuitable for open repair
  68. 68. 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
  69. 69. EVAR 2  “EVAR did not improve survival over no intervention…”  “ongoing need for surveillance and reintervention…”  “Substantially increased costs…”  “Improving fitness a priority”
  70. 70. EVAR 1 Mortality RDE EVAR Mortality 0.5% at 30 days
  71. 71. BUT…….  Aim of endovascular repair is  The isolation of the aneurysm from the circulation  De-pressurisation of the sac  Prolonging life by preventing rupture
  72. 72. EVAR 1 Complications RDE EVAR Reinterventions ~2% at 5 years
  73. 73. 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?
  74. 74. 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
  75. 75. 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
  76. 76. Summary  25,000 invitations  85% attendance  Approx £10 per scan  99% imaging success  1% of aortas > 4cm diameter
  77. 77. AAA related mortality for Gloucestershire 50 45 40 35 30 25 65-73 Other 20 15 10 5 0 1994 1995 1996 1997 1998
  78. 78. Majority of deaths in 15% who declined screening
  79. 79. 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
  80. 80. Conclusion Single normal ultrasound at age 65 effectively rules out the risk of clinically significant aneurysmal disease
  81. 81. 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
  82. 82. 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

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