Coarctation Of Aorta

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Coarctation Of Aorta

  1. 1. Coarctation of Aorta Seoul National University Hospital Department of Thoracic & Cardiovascular Surgery
  2. 2. Coarctation of Aorta <ul><li>1. Definition </li></ul><ul><li>A congenital narrowing of upper descending thoracic aorta </li></ul><ul><li>adjacent to the site of attachment of ductus arteriosus </li></ul><ul><li>2. History </li></ul><ul><li>Morgagni : 1st description in 1760 </li></ul><ul><li>Bonnett : postductal & preductal type in 1903 </li></ul><ul><li>Crafoord : 1st coarctation repair in 1944 </li></ul><ul><li>Vorsschulte : prosthetic onlay graft or vertical incision </li></ul><ul><li>and transverse closure in 1957 </li></ul><ul><li>Waldhausen : subclavian patch aortoplasty in 1966 </li></ul>
  3. 3. Coarctation of Aorta <ul><li>Developmental factor </li></ul><ul><li>1. Underdevelopment or hypoplasia of aortic </li></ul><ul><li>arch or isthmus </li></ul><ul><li>Definition of hypoplasia </li></ul><ul><li>* Proximal arch : 60% of ascending aorta </li></ul><ul><li>* Distal arch : 50% of ascending aorta </li></ul><ul><li>* Isthmus : 40% of ascending aorta </li></ul><ul><li>2. Presence of ectopic ductal tissue in the aorta </li></ul>
  4. 4. Aortic Arch Hypoplasia <ul><li>Definition </li></ul><ul><li>Hypoplastic arch has higher ratio of elastin lamellae to vessel diameter & increase in collagen and decrease in alpha-actin-positive cell that may hinder the ability of arch to distend . </li></ul><ul><li>1. 50% reduction of terminal end of ascending aorta, sometimes, </li></ul><ul><li>because of small ascending aorta in coarctation, descending </li></ul><ul><li>thoracic aorta is compared. </li></ul><ul><li>2. Transverse arch diameter less than body weight in Kg plus 1 </li></ul><ul><li>3. Z-value less than –2 or more </li></ul>
  5. 5. Coarctation of Aorta <ul><li>Morphology </li></ul><ul><li>1. Localized stenosis </li></ul><ul><li>* More than 50% reduction in cross sectional area </li></ul><ul><li>* Shelf, projection, infolding of aortic media into the </li></ul><ul><li>lumen opposite the ductus arteriosus </li></ul><ul><li>* Usually intimal hypertrophy ( intimal veil ) extends </li></ul><ul><li>the shelf circumferentially and further narrows the </li></ul><ul><li>lumen (Rodbard) </li></ul><ul><li>2. Tubular hypoplasia </li></ul><ul><li>* Severe with lesser narrowing </li></ul><ul><li>* Proximal aortic & arterial wall </li></ul><ul><li>* Distal aortic arch narrowing </li></ul><ul><li>* Fetal flow pattern (Rudolph) </li></ul>
  6. 6. Coarctation of Aorta <ul><li>Evolution </li></ul>
  7. 7. Coarctation of Aorta <ul><li>Pathophysiology </li></ul><ul><li>Narrowed aorta produces increased left ventricular afterload and wall stress, left ventricular hypertrophy, and congestive heart failure. </li></ul><ul><li>Systemic perfusion is dependent on the ductal flow and collateralization in severe coarctation </li></ul>
  8. 8. Coarctation of Aorta <ul><li>Associated pathology </li></ul><ul><li>1. Collateral circulation </li></ul><ul><li>* Inflow : primary from branches of both subclavian arteries </li></ul><ul><li>. internal mammary artery . vertebral artery </li></ul><ul><li>. costocervical trunk . thyrocervical trunk </li></ul><ul><li>* Outflow : into descending aorta, two pairs of intercostal arteries </li></ul><ul><li>2. Aneurysm formation of intercostal arteries </li></ul><ul><li>* 3rd, & 4th rib notching * rare before 10 years of age </li></ul><ul><li>3. Coronary artery dilatation and tortuosity </li></ul><ul><li>* due to LVH </li></ul><ul><li>4. Aortic valve </li></ul><ul><li>* bicuspid (27-45%) * stenosis ( 6 - 7%) </li></ul><ul><li>5. Intracranial aneurysm </li></ul><ul><li>* berry type intracranial aneurysm in some patients </li></ul><ul><li>6. Associated cardiac anomaly </li></ul><ul><li>* 85% of neonates presenting COA </li></ul>
  9. 9. CoA Localized
  10. 10. CoA Tubular Hypoplasia PDA Distal arch
  11. 11. Coarctation of Aorta <ul><li>Natural history </li></ul><ul><li>1. Incidence </li></ul><ul><li>* 5-8% of CHD (5 per 10000 live births) </li></ul><ul><li>* Isolated CoA (82% of total CoA) ; male:female = 2:1 </li></ul><ul><li>CoA + VSD 11%, COA + other cardiac anomalies 7% </li></ul><ul><li>* Complex CoA ; no sex difference </li></ul><ul><li>2. Survival of pure CoA </li></ul><ul><li>* 15% : CHF in neonate or infancy </li></ul><ul><li>* 85% : survive late childhood without operation </li></ul><ul><li>* 65% : survive 3rd decade of life (2% at 60 years) </li></ul><ul><li>3. Bacterial endocarditis : common in 1 st 5 decades </li></ul><ul><li>4. Aortic rupture : 2~3rd decade </li></ul><ul><li>5. Intracranial lesion : subarachnoid hemorrhage(cong. Berry </li></ul><ul><li>aneurysm) </li></ul>
  12. 12. Collaterals in CoA
  13. 13. Coarctation of Aorta <ul><li>Clinical features & diagnosis </li></ul><ul><li>1. Infancy </li></ul><ul><li>1) Closure of ductus (7-10 days) produces severe obstruction </li></ul><ul><li>2) Ductus arteriosus remains patent - differential cyanosis </li></ul><ul><li>3) Associated intracardiac defect - more severe, early onset </li></ul><ul><li>4) Degree of collateral circulation </li></ul><ul><li>2. Childhood </li></ul><ul><li>* Asymptomatic without significant associated lesion </li></ul><ul><li>* Hypertension (90%) * Cardiomegaly (33%) </li></ul><ul><li>* Rib notching (15%) </li></ul><ul><li>3. Adolescence and adult </li></ul><ul><li>* Hypertension ; very common * Valvar heart disease </li></ul><ul><li>* Heart failure at 30 years of age </li></ul><ul><li>4. Associated syndrome </li></ul><ul><li>* Turner syndrome (XO) : 2% * Von Recklinghausen’s D </li></ul><ul><li>* Noonan’s syndrome or congenital rubella </li></ul>
  14. 14. Coarctation of Aorta <ul><li>Indications for operation </li></ul><ul><li>1. Reduction of luminal diameter greater </li></ul><ul><li>than 50% at any age </li></ul><ul><li>2. Upper body hypertension over 150mmHg </li></ul><ul><li>in young infant ( not in heart failure ) </li></ul><ul><li>3. CoA with congestive heart failure </li></ul><ul><li>at any age </li></ul>
  15. 15. Coarctation of Aorta <ul><li>Techniques of operation </li></ul><ul><li>1. Subclavian flap aortoplasty </li></ul><ul><li>Neonate, infant and child up to 10 years </li></ul><ul><li>2. End-to-end anastomosis </li></ul><ul><li>Preferred in any age group </li></ul><ul><li>* Extended end-to-end anastomosis </li></ul><ul><li>* Radically extended end-to-end anastomosis </li></ul><ul><li>3. Patch angioplasty or graft replacement </li></ul>
  16. 16. Prevention of Recoarctation <ul><li>Ideal operative procedure </li></ul><ul><li>Successfully address transverse arch hypoplasia (if present), </li></ul><ul><li>Resection of all ductal tissue, and </li></ul><ul><li>Prevention of residual circumferential scarring at the aortic anastomotic sit. </li></ul><ul><li>Factors </li></ul><ul><li>Younger age at operation </li></ul><ul><li>Presence of aortic arch hypoplasia remain risk factors for recoarctation </li></ul>
  17. 17. Regional Cerebral Perfusion <ul><li>Technique </li></ul><ul><li>We begin full-flow CPB at a calculated baseline of 150 mL · kg–1 · min–1 and, after snare placement on the proximal brachiocephalic vessels, initiate RLFP by reducing pump flow to 50% of baseline. </li></ul><ul><li>We make further adjustments such that baseline cerebral blood flow velocity as measured by transcranial Doppler and cerebral oximetrics as measured by NIRS are optimally maintained. </li></ul><ul><li>RLFP provides consistent cerebral circulatory support and that this support is bilateral, despite being applied to the inominate artery. </li></ul>
  18. 18. Pediatric Cardiac Surgery <ul><li>Neurologic complications </li></ul><ul><li>Incidence of 2.3% for overt clinical presentation & up to 60% when sensitive magnetic resonance imaging is applied in heart surgery of infants & children. </li></ul><ul><li>In control of the arch proximal to the left carotid artery, during COA surgery, this assumes that collateral blood flow and completeness of the circle of Willis allows for a favorable and even distribution of cerebral blood flow. </li></ul><ul><li>But patients undergoing coarctation repair, proximal occlusion of the aortic arch results in transient but significant impairment in contralateral cerebral oxygen balance </li></ul>
  19. 19. Blood Supply to Spinal Cord The most important blood supply to spinal cord comes from spinal artery, a minor supply is from Adamkiewicz artery
  20. 20. CoA Exposure
  21. 21. CoA LSCA flap
  22. 22. CoA Patch Augmentation
  23. 23. CoA Subclavian Artery Flap
  24. 24. CoA End-to-End Anastomosis
  25. 25. CoA Extended end-to-end Anastomosis
  26. 26. Coactation of Aorta Resection and Anastomosis
  27. 27. Coactation of Aorta Resection & Extended end-to-end Anastomosis
  28. 28. Coarctation of Aorta End-to-Side Anastomosis
  29. 29. Coarctation of Aorta Enlargement of VSD, Resection of Conal Septum
  30. 30. CoA + VSD, One-stage Repair
  31. 31. CoA + VSD, One-stage Repair
  32. 32. Coarctation of Aorta End-to-Side Anastomosis Opening of Resected Segment
  33. 33. Coactation of Aorta <ul><li>Operative results </li></ul><ul><li>Hospital mortality </li></ul><ul><li>Causes of early death are </li></ul><ul><li>acute and chronic cardiac failure or severe </li></ul><ul><li>pulmonary insufficiency </li></ul><ul><li>Incremental risk factor for death </li></ul><ul><li>1) Older age </li></ul><ul><li>2) Hypoplastic left heart class </li></ul><ul><li>3) Techniques of operation </li></ul>
  34. 34. Coactation of Aorta <ul><li>Operative results </li></ul><ul><li>Mobidity </li></ul><ul><li>1) Paraplegia (0.2 ~ 1.5%) </li></ul><ul><li>2) Hypertension and abdominal pain </li></ul><ul><li>3) Persistent or recurrent coarctation </li></ul><ul><li>- more than 20mmHg </li></ul><ul><li>- high incidence in young </li></ul><ul><li>4) Upper body hypertension without resting gradient </li></ul><ul><li>- increased vascular activity in the forearm </li></ul><ul><li>- age at operation is risk factor </li></ul><ul><li>5) Late aneurysm formation </li></ul><ul><li>- higher in onlay patch technique </li></ul><ul><li>6) Valvular disease </li></ul><ul><li>7) Congestive heart failure with hypertension </li></ul><ul><li>8) Bacterial endocarditis </li></ul>
  35. 35. Coactation of Aorta <ul><li>Special features of postoperative care </li></ul><ul><li>1. Systemic arterial hypertension </li></ul><ul><li>Usually, but infant or young child doesn’t </li></ul><ul><li>need to be treated. </li></ul><ul><li>2. Abdominal pain </li></ul><ul><li>Usually mild abdominal discomfort for a few days, </li></ul><ul><li>and prominent in 5 - 10%. </li></ul><ul><li>Control hypertension, nasogastric decompression, </li></ul><ul><li>IV maintain </li></ul><ul><li>3. Chylothorax </li></ul><ul><li>5% </li></ul>
  36. 36. Coactation of Aorta Repair <ul><li>Postoperative hypertension </li></ul><ul><li>Sealy </li></ul><ul><li>Altered baroreceptor response with increased excretion of epinephrine or norepinephrine </li></ul><ul><li>Rocchin </li></ul><ul><li>Sympathetic nervous system in early phase, and renin-angiotensin system in late phase </li></ul>
  37. 37. Coactation of Aorta Repair <ul><li>Paraplegia </li></ul><ul><li>1. Duration of spinal cord ischemia </li></ul><ul><li>2. Duration of intercostal artery ischemia </li></ul><ul><li>3. Intraoperative proximal hypotension </li></ul><ul><li>4. Postoperative hypotension </li></ul><ul><li>5. Hyperthermia during operation </li></ul><ul><li>6. Anastomosis with tension </li></ul><ul><li>7. Acidosis in the perioperative periods </li></ul>
  38. 38. Coactation of Aorta <ul><li>Special situation & controversies </li></ul><ul><li>1. CoA proximal to left subclavian artery </li></ul><ul><li>* 1% of all COA </li></ul><ul><li>* reverse subclavian flap </li></ul><ul><li>* abdominal CoA : 0.5 ~ 2% </li></ul><ul><li>2. Mild or moderate coarctation </li></ul><ul><li>* degenerative change prone to occur </li></ul><ul><li>3. Prevention of paraplegia </li></ul><ul><li>* Collateral circulation, hypothermia(< 45min at 33 deg C) </li></ul><ul><li>* Descending aortic pressure under 50mmHg after clamp </li></ul><ul><li>4. Recurrent coarctation </li></ul><ul><li>Increased mortality and morbidity </li></ul><ul><li>5. CoA with VSD or other anomalies </li></ul><ul><li>Increased mortality and morbidity </li></ul>
  39. 39. Coactation of Aorta <ul><li>Balloon dilatation </li></ul><ul><li>The role of balloon dilatation is controversial because of early restenosis, the need for multiple interventions, potential limb ischemia, and the increased risk of aneurysm formation </li></ul><ul><li>The mechanism for early restenosis in neonates may be related to multiple factors including ductal tissue constriction or recoil, isthmus hypoplasia, intimal hyperplasia as a result of smooth muscle cell proliferation, and matrix protein production with arterial remodeling are involved in restenosis </li></ul>

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