Coarctation of Aorta by Dr. Teferi E pptx

Coarctation of Aorta

1. COARCTATION OF AORTA By- Teferi E. (Cardiac fellow) Moderator- Dr. Tewodros G. ( pediatric cardiologist) June,6--2024

2. Outline Introduction Epidemiology Embryology Classification Morphological feature Pathophysiology Manifestation Diagnostic modality Management References

3. Coarctation (CoA) is a narrowing of the aorta, usually located at the insertion of the ductus arteriosus, just distal to the left subclavian artery. The narrowing may be isolated and discrete, or may involve a long segment , associated with transverse arch hypoplasia.

4. Nomenclature Coarctatus ( latin )—contracted tightened & pressed together. Haemodynamically significant congenital narrowing of upper descending thoracic aorta adjacent to DA. Interrupted aortic arch –lumen is atretic short distance separate aortic ends. primary/isolated CoA /PDA – with out other associated anomalies

5. Nomenclature

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7. Prevalence & Genetics CoA is 4% - 8% of all CHDs . M > F Increased familial risk in congenital LVOT obstructive lesions, including CoA. Most cases are sporadic, at least 21% to 35% of Turner syndrome have CoA, & 5% to 12% of females with CoA also have TS Can CoA be acquired?

8. Critical cardiac defect with a high early mortality if not treated immediate after birth includes HLHS, coarctation of the aorta (COA) / interrupted aortic arch (IAA), TGA, TAPVR, critical aortic stenosis (AS), pulmonary atresia (PA) and tricuspid atresia (TA).

9. Embryology Theories Flow theory Ductus sling theory

10. I. Flow theory Any congenital anomaly that reduced flow across aortic isthmus during fetal life leads to poor development of isthmus “ no flow no grow” In normal fetus the isthmus receives only 10% of CCO , which explain that the normal neonatal isthmus diameter is only 70% of the diameter of ascending aorta. Intracardiac lesions that diminish the volume of LV promote the development of CoA.

11. Shone complex Left inflow membrain / ms 2. Left outflow sub valvar AS 3. Aortic arch/isthmus CoA

12. II. The ductal sling theory In 1855, Skoda speculated that the constriction of the aorta is resulted to the closure of the DA extending in to the walls of the aorta. Coarctation develops as the result of migration of ductal smooth muscle cells in to the periductal aorta, with subsequent constriction and narrowing of the aorta.

13. Classification 1903 BONNETT infantile –preductal, Adult – post ductal Amato et al Primary CoA. CoA with isthmic hypoplasia CoA with tubular hypoplasia/ isthmus & segment A- with VSD B- other major cardiac defect

14. Classification Surgical classification Isolated CoA Coa with VSD CoA With complex intracardiac anomaly

15. PDA large & provide blood flow to lower extremity Tubular narrowing of isthmus No shelf like narrowing in aorta Minimal post stenotic dilatation of aorta Minor enlargement of intercostal arteries Duct is closed No narrowing of isthmus Shelf like narrowing in aorta post stenotic & pre stenotic aorta is dilated Intercostal arteries grossly dilated

16. The most common site is aortic isthmus, the arterial duct/ligament & descending aorta Crossectional area reduced by at least 50%

17. Morphological features Discrete CoA Post ductal/adult Associated cardiac lesions rare Well dev elop collateral circula tion rare < 5yr External -sharp indentation at COA site Internal – obstructing shelf Changes -post stenotic dilatation -collateral formation

18. Tubular hypoplasia Preductal/infantile Associated with major cardiac anomalies Secondary /collateral changes are rare External continuity of PDA & descending aorta

19. Collateral circulation Seen mostly in isolated coarctaion Usually symmetrical on both sides In flow is from subclavian artery branches Out flow in to Descending aorta Mostly 3red & 4 th intercostals

20. Collateral circulation

21. Rib notching Seen in older patients Uncommon < 5yrs Seen in 3 rd to 9 th rib posteriorly Why in first 2 ribs absent?? Erosion of inferior surfaces of posterior ribs

22. Associated anomalies Cardiac anomalies PDA in all cases of preductal Left side obstructive lesions aortic stenosis/ atresia,BAV , shone syndrome VSD in 40%

23. COA with MV abnormality Seen in 25% 10% have MR MS- Parachute mitral valve/hypoplasia of mitral valve ring

24. COA with AS BAV 50—80% of CoA 21% of COA have aortic valve disease Valvular/sub valvar Decrease CO with poor pulse in all extremities masking upper & lower extremity pulse difference.

25. Extracardiac vascular anomalies Intracranial aneurysms Variations in Brachiocephalic artery anatomy Dissecting aortic aneurysm Vascular ring ---double aortic arch

26. Associated syndrome Turners syndrome Noonan syndrome Congenital rubella Neurofibromatosis type 1

27. Pathophysiology Degree of obstruction Type of coarctation Rapidity of development of obstruction Status of ductus arteriosus State of collateral development Presence of associated intracardiac lesions

28. Coarctation with IVS & closed PDA SVR >>asc.AO PDA closure >>>dec. dec aorta LV pressure >> LA pressure

29. Effect of PGE1 Relaxes the ductus smooth muscle that has extended in to the aortic wall Maintains patency of ductus arteriosus Effective with in 7-10 days For pre-operative stabilization 100% oxygen >>> early PDA closure>>> increase coarctaion gradient

30. Coarctation with IVS & collateral formation Collateral formation >>> Asc Aorta requires less pressure to maintain distal flow >>> decrease LV afterload --- CCF improves

31. Coarctation with small VSD Insignificant effect on infants Increase LV pressure >>>large shunt Leading to moderate PAH If VSD large Large left to right shunt Increase PA pressure >>> PVD early

32. Complications of longstanding CoA Post-stenotic dilation of upper descending thoracic aorta Collateral formation which may become aneurysma l Degenerative changes ( saccular aneurysm formation, intimal erosion with dissection) Hypertension

33. Mycotic aneurysm & bacterial endocarditis in CoA

34. Dissecting aneurysm in complicating CoA

35. Hypertension with COA Etiology Mechanical obstruction Reactivity of arteriolar resistance vessels Decrease compliance of aortic wall Increase plasma renin activity Resetting of baroreceptor reflex

36. Natural history 5-7% of CHD 80% of theses are isolated COA with or with out PDA Untreated isolated C oA 1 ST month =10 % acute CHF 1 st year 20% --CHF 1—4yrs 10% chronic CHF

37. Natural history 20yrs of age—25% will die 32yrs of age—50% will die 46yrs of age—75% will die 58yrs of age—90% will die Articles Natural history of coarctation of the aorta Maurice Campbell Cardiac Department, Guy's Hospital, London S.E.1, and the Institute of Cardiology, London W.1 Abstract ………………. The two methods give results in close agreement, closer than could be expected considering the relatively small numbers of patients and patient-years. The percentages of deaths at the end of each decade found by the two methods never differ by more than ±4 per cent and are often much closer . Of those surviving the serious hazards of the first one or two years, 25 per cent die before they reach 20, 50 per cent by 32, 75 per cent by 46, and 90 per cent by 58 years. The arithmetical mean of the ages of death is 34 years instead of 71 years as normally. These means, however, hide a very wide range, with standard deviations of at least ±15 per cent . For coarctation the median is 31 years and the mode is widely spread through the second to fifth decades rather than closely clustered round a point. .

38. Common causes of death Congestive heart failure (26%), Aortic rupture (21%), Endocarditis (18%), and Intracranial hemorrhage (12%)

39. Natural history Aortic rupture 2—3 rd decade Usually ascending Aorta leading to hemopericardium with tamponade Coarctation with intracranial lesions SAH from rapture of congenital berry aneurism on circle of Willis arteries ---cause of rapture associate with HTN Emboli /IE

40. Pseudocoarctation is  a very rare anomaly of kinking, of the aorta without a pressure gradient across the lesion . Elongated tortuous ,dilated distal to aortic arch It is thought to be of congenital origin, and characterized by elongation and kinking of the aorta at the level of the ligamentum

41. Clinical manifestation Neonates & infants –CCF PDA closes—sudden CCF, shock, MODS,RF & NEC,DEATH Childhood ---usually asymptomatic , hypertension Adolescence & adult life ---asymptomatic, reduced femoral pulse, HTN, murmur Head ach,epistaxis,claudication, complications— ic hemorrge , ccf ,dissection

42. Physical examination GA Vital sign Pulse -- Brachio -femoral delay Left radial pulse weak---LSCA stenosis Right radial pulse weak—Aberrant RSCA

43. Physical examination

44. Differential cyanosis PDA R—L shunt, LV pressure & volume overload may produce a prominent heaving impulse at apex

45. Blood pressure SBP gradient Difference b/n UL & LL BP >20mmhg Echo gradient across CoA >20mmhg Cath withdrawal gradient >20mmhg The gradient will increase with exercise Hypertension

46. Murmurs Systolic EM— coarctation , base & left inter scapular area posteriorly Continuous ---collaterals, anterior thorax, left sternal,& suprasternal, right infra clavicular

47. Diagnostic methods ECG usually has a normal electrocardiogram. RVH suggest PAH

48. CXR Cardiomegaly with increased pulmonary vascular markings. Classic“3 sign” Rib notching

49. Echocardiography 2D echocardiography is definitive study in newborns Associated anomaly & severity

50. Continuous-wave Doppler

51. Cardiac catheterization & Aortography To confirm the Dx in older & doubtful Define the anatomy, location & severity Hypoplasia of arch Ducts Collaterals Aneurysm Pulmonary vasculature

52. Diagnostic methods CT/MRI Increasingly used beyond infancy instead of CAT Indicated if >20yrs due to high prevalence of aneurysm

53. Management Medical management Stabilization of Neonates and Infants Optimization of hemodynamics with inotropes & diuretics PGE1 promote ductal patency & improves perfusion of descending aorta relaxation of the aortic end If required intubation & mechanical ventilation

54. Surgical management Heart failure & cardiogenic shock Peak CoA pressure gradient of 20 mm Hg or more Supine blood pressure gradient of over 20 mm Hg between upper and lower extremities Upper extremity hypertension in a patient with CoA Reduction of luminal diameter >50%

55. Surgical techniques Resection & End to End anastomosis Prosthetic patch aortoplasty Subclavian Flap Aortoplasty Resection with Extended End-to-End Anastomosis Balloon Dilation Angioplasty Stent

56. Resection & End-to-End Anastomosis Described by Crafoord & Nylin 1944 the first successful resection & end-to-end anastomosis. The narrowed coarctation segment is excised with a direct end-to-end circumferential anastomosis of the aorta. Ductus is ligated & divided

57. Resection & End-to-End Anastomosis

58. Dis-advantage High recoarctation rate 20–86% , particularly in the age of < 1yr. Does not address the issue of a hypoplastic transverse. Not easily applicable to older children

59. Prosthetic Patch Aortoplasty Vossschulte in 1961 described The aorta is then incised longitudinally through the site of the coarctation, with prolongation of incision above and below Patch can extent up to LSCA

60. Disadvantage Aneurysmal formation of aortic wall opposite to patch Recoarctation 9%

61. Subclavian Flap Aortoplasty Introduced by Waldhausen and Nahrwold in 1966. Indicated only in infants the aorta clamped proximal to LSCA distal to COA LSCA ligated distally The aorta is opened longitudinally & incision extend to LSCA The subclavian flap is folded on to the aorta

62. Disadvantages Left arm ischemia ? Poor growth & function of left upper limb Aneurysm formation Recoarctation 13%

63. Resection with extended E to E anastomosis Ductal tissue & coarct segment excised, incision made in transverse arch MR 2%, Recoarctation 4% Current procedure of choice for infants <1yr ,

64. Balloon dilation angioplasy Described by sos in 1979 With major systemic illness that increase risk of surgery Older pts with mild discrete coarctation with poor collateral For dilation of recurrent coarctation

65. BAP Aneurysmal formation near dilation site Residual gradient > 20mmhg Aortic rupture

66. Endovascular Stents Latest Platinum advantage - No restenosis/aneurysm -Re expanded at later age Re-CoA, aortic aneurysm formation, and rupture after balloon angioplasty can be treated effectively with a covered stent

67. Potential Complications of surgery Recoarctation Paradoxical hypertension Aneurysm formation Bleeding, Injury to the recurrent laryngeal nerve, Chylothorax, Phrenic nerve injury Left arm ischemia Paraplegia Prolonged mechanical ventilation,

68. Paradoxical post-op hypertension postcoarctectomy syndrome Two stage response 1 st response due to release of stretch on baroreceptor on carotid bodies after removal of obstruction 2 nd response is due to elevated level of renin angiotensin , asperse with in 2-3 days of 1 st response.

69. Complication of hypertensin on post operative period Mesenteric arteritis & ischemia – abdominal pain, distension , NEC -- keep NPO for 48hr

70. Treatment post operative HTN In immediate post-op period Esmolol & nicardipine can be used ACE inhibitors for second phase Pre-op administration of propranolol is useful in blunting sympathetic response

71. There is tendency of persistence of post operative hypertension proportional to age of patient

72. Aneurysm formation Risk Patch aortoplasty at advanced age Operation on Recoarctation Use of decron patch

73. Recoarctation Risk Age < 2month Wt < 2kg Residual ductal tissue Use of silk sutures for anastomosis

74. References Moss & Adams’ heart disease in infants, children, and adolescent Robert H. Anderson Edward J. Baker Daniel J. Penny Andrew Pediatric cardiology, TOF with pulmonary stenosis 36: 753-785 Narain Moorjani,Nicola Viola, Congenital-Cardiac-Surgery- TFM,Publishing 2022.pdf Park’s pediatric cardiology J.W. Brown et al. / European Journal of Cardio-thoracic Surgery 20 (2001) 221±227 https://people4people.in/ https://pedecho.org/about

75. THANK YOU

76. Paraplegia