主动脉缩窄疾病课件.ppt

1、Coarctation of Aorta,Seoul National University Hospital Department of Thoracic & Cardiovascular Surgery,Coarctation of Aorta,1. DefinitionA congenital narrowing of upper descending thoracic aorta adjacent to the site of attachment of ductus arteriosus2. HistoryMorgagni : 1st description in 1760Bonne

2、tt : postductal & preductal type in 1903Crafoord : 1st coarctation repair in 1944Vorsschulte : prosthetic onlay graft or vertical incision and transverse closure in 1957Waldhausen : subclavian patch aortoplasty in 1966,Coarctation of Aorta,Developmental factor 1. Underdevelopment or hypoplasia of ao

3、rticarch or isthmusDefinition of hypoplasia* Proximal arch : 60% of ascending aorta* Distal arch : 50% of ascending aorta * Isthmus : 40% of ascending aorta 2. Presence of ectopic ductal tissue in the aorta,Aortic Arch Hypoplasia,Definition Hypoplastic arch has higher ratio of elastin lamellae to ve

4、ssel diameter & increase in collagen and decrease in alpha-actin-positive cell that may hinder the ability of arch to distend.1. 50% reduction of terminal end of ascending aorta, sometimes,because of small ascending aorta in coarctation, descending thoracic aorta is compared.2. Transverse arch diame

5、ter less than body weight in Kg plus 13. Z-value less than 2 or more,Coarctation of Aorta,Morphology 1. Localized stenosis * More than 50% reduction in cross sectional area* Shelf, projection, infolding of aortic media into thelumen opposite the ductus arteriosus* Usually intimal hypertrophy ( intim

6、al veil ) extendsthe shelf circumferentially and further narrows thelumen (Rodbard) 2. Tubular hypoplasia* Severe with lesser narrowing * Proximal aortic & arterial wall* Distal aortic arch narrowing* Fetal flow pattern (Rudolph),Coarctation of Aorta,Evolution,Coarctation of Aorta,Pathophysiology Na

7、rrowed aorta produces increased left ventricular afterload and wall stress, left ventricular hypertrophy, and congestive heart failure. Systemic perfusion is dependent on the ductal flow and collateralization in severe coarctation,Coarctation of Aorta,Associated pathology 1. Collateral circulation*

8、Inflow : primary from branches of both subclavian arteries. internal mammary artery . vertebral artery. costocervical trunk . thyrocervical trunk* Outflow : into descending aorta, two pairs of intercostal arteries 2. Aneurysm formation of intercostal arteries* 3rd, & 4th rib notching * rare before 1

9、0 years of age 3. Coronary artery dilatation and tortuosity* due to LVH 4. Aortic valve* bicuspid (27-45%) * stenosis ( 6 - 7%) 5. Intracranial aneurysm* berry type intracranial aneurysm in some patients 6. Associated cardiac anomaly* 85% of neonates presenting COA,CoA Localized,CoA Tubular Hypoplas

10、ia,PDA,Distal arch,Coarctation of Aorta,Natural history 1. Incidence* 5-8% of CHD (5 per 10000 live births)* Isolated CoA (82% of total CoA) ; male:female = 2:1CoA + VSD 11%, COA + other cardiac anomalies 7%* Complex CoA ; no sex difference 2. Survival of pure CoA* 15% : CHF in neonate or infancy* 8

11、5% : survive late childhood without operation* 65% : survive 3rd decade of life (2% at 60 years) 3. Bacterial endocarditis : common in 1st 5 decades 4. Aortic rupture : 23rd decade 5. Intracranial lesion : subarachnoid hemorrhage(cong. Berry aneurysm),Collaterals in CoA,Coarctation of Aorta,Clinical

12、 features very common * Valvar heart disease* Heart failure at 30 years of age 4. Associated syndrome* Turner syndrome (XO) : 2% * Von Recklinghausens D * Noonans syndrome or congenital rubella,Coarctation of Aorta,Indications for operation 1. Reduction of luminal diameter greaterthan 50% at any age

13、 2. Upper body hypertension over 150mmHgin young infant ( not in heart failure ) 3. CoA with congestive heart failure at any age,Coarctation of Aorta,Techniques of operation1. Subclavian flap aortoplasty Neonate, infant and child up to 10 years2. End-to-end anastomosisPreferred in any age group* Ext

14、ended end-to-end anastomosis * Radically extended end-to-end anastomosis3. Patch angioplasty or graft replacement,Prevention of Recoarctation,Ideal operative procedure Successfully address transverse arch hypoplasia (if present), Resection of all ductal tissue, and Prevention of residual circumferen

15、tial scarring at the aortic anastomotic sit. Factors Younger age at operation Presence of aortic arch hypoplasia remain risk factors for recoarctation,Regional Cerebral Perfusion,Technique We begin full-flow CPB at a calculated baseline of 150 mL kg1 min1 and, after snare placement on the proximal b

16、rachiocephalic vessels, initiate RLFP by reducing pump flow to 50% of baseline. 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. RLFP provides consistent cerebral circ

17、ulatory support and that this support is bilateral, despite being applied to the inominate artery.,Pediatric Cardiac Surgery,Neurologic complications Incidence of 2.3% for overt clinical presentation & up to 60% when sensitive magnetic resonance imaging is applied in heart surgery of infants & child

18、ren. 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. But patients undergoing coarctation repair, proximal occlusion of

19、 the aortic arch results in transient but significant impairment in contralateral cerebral oxygen balance,Blood Supply to Spinal Cord,The most important blood supply to spinal cord comes from spinal artery, a minor supply is from Adamkiewicz artery,CoA Exposure,CoA LSCA flap,CoA Patch Augmentation,C

20、oA Subclavian Artery Flap,CoA End-to-End Anastomosis,CoA Extended end-to-end Anastomosis,Coactation of Aorta Resection and Anastomosis,Coactation of Aorta Resection & Extended end-to-end Anastomosis,Coarctation of Aorta End-to-Side Anastomosis,Coarctation of Aorta Enlargement of VSD, Resection of Co

21、nal Septum,CoA + VSD, One-stage Repair,CoA + VSD, One-stage Repair,Coarctation of Aorta End-to-Side Anastomosis,Opening of Resected Segment,Coactation of Aorta,Operative results Hospital mortalityCauses of early death areacute and chronic cardiac failure or severe pulmonary insufficiency Incremental

22、 risk factor for death1) Older age2) Hypoplastic left heart class3) Techniques of operation,Coactation of Aorta,Operative results Mobidity1) Paraplegia (0.2 1.5%)2) Hypertension and abdominal pain3) Persistent or recurrent coarctation- more than 20mmHg - high incidence in young 4) Upper body hyperte

23、nsion without resting gradient- increased vascular activity in the forearm- age at operation is risk factor 5) Late aneurysm formation- higher in onlay patch technique6) Valvular disease7) Congestive heart failure with hypertension8) Bacterial endocarditis,Coactation of Aorta,Special features of pos

24、toperative care 1. Systemic arterial hypertensionUsually, but infant or young child doesnt need to be treated. 2. Abdominal painUsually mild abdominal discomfort for a few days,and prominent in 5 - 10%.Control hypertension, nasogastric decompression, IV maintain 3. Chylothorax 5%,Coactation of Aorta

25、 Repair,Postoperative hypertension SealyAltered baroreceptor response with increased excretion of epinephrine or norepinephrine RocchinSympathetic nervous system in early phase, and renin-angiotensin system in late phase,Coactation of Aorta Repair,Paraplegia 1. Duration of spinal cord ischemia 2. Du

26、ration of intercostal artery ischemia 3. Intraoperative proximal hypotension 4. Postoperative hypotension 5. Hyperthermia during operation 6. Anastomosis with tension 7. Acidosis in the perioperative periods,Coactation of Aorta,Special situation & controversies 1. CoA proximal to left subclavian art

27、ery* 1% of all COA* reverse subclavian flap* abdominal CoA : 0.5 2%2. Mild or moderate coarctation* degenerative change prone to occur3. Prevention of paraplegia* Collateral circulation, hypothermia( 45min at 33 deg C)* Descending aortic pressure under 50mmHg after clamp 4. Recurrent coarctationIncr

28、eased mortality and morbidity5. CoA with VSD or other anomalies Increased mortality and morbidity,Coactation of Aorta,Balloon dilatation The role of balloon dilatation is controversial because of early restenosis, the need for multiple interventions, potential limb ischemia, and the increased risk o

29、f aneurysm formation 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,