TAPVC-完全性肺静脉畸形引流课件(1).ppt

1、TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION,CJ JORDAAN 29/01/04,Definition:,Uncommon congenital cardiac defect (1-3%) in which there is no direct communication between the pulmonary venous drainage and the Left Atrium. All the pulmonary veins connect/drain to the Right atrium.,Embryology:,Total anom

2、alous pulmonary venous connection (TAPVC) develops when the primordial pulmonary vein fails to unite with the plexus of veins surrounding the lung buds. This results in return of pulmonary venous blood to the heart via a systemic vein, and subsequently to the right atrium.,Classification:,TAPVC is c

3、lassified according to the site of connection: Supra cardiac: includes connections to the left Innominate vein, the SVC, or the Azygos Cardiac: includes connections to the coronary sinus or directly to the right atrium Infra cardiac: includes connections below the diaphragm to the portal vein, hepat

4、ic veins, ductus venosus or IVC. Mixed: involves connections of two or more of these types; at least one of the main lobar pulmonary veins is draining differently from the others Each category can be further classified as obstructive or non-obstructive.,1. Supra cardiac TAPVC:,Most common form of TA

5、PVC-45% Bilat draining of pulmonary veins (PV) to Common Pulmonary Venous Sinus (CPVS). This confluence drains via Vertical Vein (VV) to Innominate vein, SVC or Azygos. Stenosis common ( +/- 40-60%): Pulmonary vein systemic connection, Vascular vice or Long thin VV,-CPVC locationSupra cardiac TAPVC

6、-Sites of stenosis,2. Cardiac TAPVC:,Accounts for 25% of TAPVC VV drains mostly to Coronary Sinus, seldom directly to Right atrium. Enlarged coronary sinus acts as the CPVS with only a thin wall of myocardium separating sinus and the Left atrium. Right atrial draining: Seen in RA isomerism. Associat

7、ed with absent Coronary sinus, huge or absent intra atrial septum. VV opens as a fibrous midline confluence. STENOSIS: Rare. May occur where the CPVS joins the Coronary sinus, or at the mouth of the coronary sinus (persisting Thebesian valve),3. Infra cardiac TAPVC:,Accounts for 25% of TAPVC The com

8、mon pulmonary vein drains through the diaphragm to the portal vein, ductus venosus or seldom to the IVC. Has the greatest propensity for STENOSIS: -May be compressed where it penetrates the Diaphragm, -Connecting vein is narrowed at its junction with the portal vein, -VV has a thickened wall with in

9、timal proliferation, -portal sinusoids (Liver) offer additional obstruction to venous return,Infra cardiac TAPVC:,4. Mixed APVC,Involves a combination of connections of two or more of the subtypes (at least one of the main lobar pulmonary veins is draining differently from the others.),Anatomy,RA: E

10、nlarged and thick walled. Decreased compliance. LA: Volume 53% less than predicted. LA auricle is normal in size, decrease in LA can be explained by the absence of the pulmonary vein component. ASD: ASD or PFO must exist for survival. Usually of adequate size and not obstructive. Obstruction leads t

11、o a decreased R to L shunt with pulmonary venous obstruction and Pulm. Hypertension. Presents as a severely sick neonate.,Anatomy,LV: Normal in size, wall thickness and mass, but decreased LV cavity ( due to leftward displacement of septum secondary to right ventricle pressure-volume overload.) RV:

12、Varies in size, depends on magnitude of pulmonary blood flow, pulmonary venous stenosis, point of PV connection. (Infra cardiac connection- RV not dilated or hypertrophied) PA: Most infants have marked pulmonary hypertension. Structural changes are usually found in the lungs even in the youngest inf

13、ants dying of TAPVC. Increase in pulm. Arterial muscularity-increase in wall thickness and extension of muscle into smaller and peripheral arteries. Vein wall thickness is also increased.,Pathophysiology:,All pulmonary venous blood returns to the right atrium. (common mixing chamber) A right-to-left

14、 shunt at the atrial level (-RV compl, ASD size, Rp) Increased pulmonary blood flow and pulmonary venous obstruction will eventually result in pulmonary hypertension. Infra diaphragmatic draining.,Pathophysiology:,Pulmonary vein stenosis: Obstruction to pulmonary draining with increase in pulm. veno

15、us pressure. Capillary leak with interstitial edema. Reflex pulm. vaso constriction and progressive increase in Rp =pulmonary hypertension. Increased PAP leads to increased RV pressures (sometimes supra systemic) with RV failure, decreased pulm. blood flow, decreased Qp:Qs, decreased systemic SAT, p

16、eripheral hypoxia and metabolic acidosis with multi organ failure. PFO obstruction: Increased LAP, impedes pulm. venous return, producing pulm. hypertension.,Burchell principle:,A direct relationship exists between the magnitude of pulm. blood flow and systemic saturation. The Qp:Qs is determined by

17、 magnitude of pulmonary blood flow, pulm. blood flow is inversely related to Rp. Thus an increase in PAP and Rp leads to a decrease in pulm blood flow with a decreased systemic SAT. SAT less than 80%: Qp:Qs likely to be 10 !,Clinical features:,Clinical features are determined by the degree of pulmon

18、ary venous obstruction. If obstruction is severe, infant will be critically ill with tachypnea, hypoxemia, and metabolic acidosis. Cyanosis can be unimpressive to severe, this is a surgical emergency. Prognosis: 50% die within 3 weeks, 75% at 5 weeks and 100% at 8-12 weeks No obstruction: Not so cri

19、tically ill. May present later with pulmonary hypertension, cardiomegaly, large pulm blood flow. Patients surviving first year of life present with failure to thrive, severe growth retardation, mild cyanosis. Stable hemodynamic state with progressive pulmonary hypertension and development of Eisenme

20、nger in their twenties.,Diagnosis:,CXR: Shows ground glass (diffuse alveolar pattern) or snowman appearance from persistent vertical vein, small heart = pulm stenosis. No stenosis: Large heart with increased pulm blood flow.,There is cardiomegaly with increased pulmonary arterial markings. There is

21、dilation of both the left and right innominate veins and the right superior vena cava producing the classical snowman or figure of 8 appearance. The superior mediastinum is enlarged secondary to dilation of the right vena cava, innominate vein and ascending vertical vein.,Neonate no stenosis,Neonate

22、 with stenosis,Diagnosis:,Echo: Diagnostic in most infants. Evaluation of cardiac chambers, Echo free space posterior to LA with abnormal drainage,Diagnosis:,Angiography,Diagnosis:,MRI angiogram:,TREATMENT:,Patients with TAPVC should undergo operative repair when the diagnosis is made Obstructed TAP

23、VC is a surgical emergency Non-obstructed TAPVC should have prompt repair as well, as the clinical status of these patients can deteriorate rapidly Early repair of non-obstructed TAPVC also prevents the adverse squeal of cyanosis and volume overload of the heart and lungs,Treatment:,Pre operatively:

24、 Admit in PICU Intubation and ventilation Tolazoline, PGE1 IVI Stabilize, correct metabolic acidosis, confirm diagnosis Prepare for emergent theatre.,Operative Technique,Cardiopulmonary bypass with hypothermic circulatory arrest is the preferred approach in critically ill infants Surgical goals are:

25、 eliminating all anomalous connections, draining the pulmonary veins into the left atrium, and closing intracardiac shunts, small PFO is left for RV decompression The PV-LA anastomosis must be large and undistorted . Problems: Small aorta Hypothermic CPB response,Left SVC connection Ligate left-side

26、d vertical vein at junction with Innominate vein Open left atrium and incise the posterior wall Find and incise the anterior wall of the confluence Anastomose the pulmonary venous confluence to the left atrium Close PFO or ASD through left atrium or through separate right atrial incision Right SVC c

27、onnection Expose pulmonary venous confluence and anastomose to left atrium as above Ligate anomalous connections or patch from within SVC A baffle may be used instead to channel flow from the right SVC through an enlarged interatrial connection Azygos connection Ligate anomalous connection Anastomos

28、e confluence to left atrium as above,2. Cardiac Type,Coronary sinus connection Classic repair: Create common large interatrial connection by incising coronary sinus septum and septum primum Close this new defect with a single patch; all pulmonary venous return and coronary sinus return now drains in

29、to the left atrium Van Praag Right atrium connection Enlarge interatrial connection Create baffle to direct flow from pulmonary venous opening across interatrial connection,3. Infracardiac Type, Ligate PDA once CPB is established Identify and ligate anomalous descending vertical vein at the diaphrag

30、m Initiate circulatory arrest Open left atrium and incise the posterior wall Find and incise the anterior wall of the confluence Anastomose the pulmonary venous confluence to the left atrium Close the interatrial communication,4. Mixed Type,Problems with Mixed Type: No pulmonary venous confluence Re

31、quires 2 or more anastomosis Smaller anastomosis predispose to pulmonary venous obstruction Risk of mortality and late pulmonary venous obstruction is increased Operative repair probably not curative,Post operative :,Pulmonary hypertensive crisis. Sedation, ventilation, Fentanyl analgesia Pco2 (30mm

32、Hg) and high PO2 TNT, PGE1, Dobutamine, Tolazoline, Adrenaline etc. Results Early (hospital) mortality ranges from 2-20% 90% of patients are cured 5-10% have late failure of repair due to pulmonary venous obstruction LA size adequate due to incorporation of PVC into LA,Post operative :,Risk Factors:

33、 Poor pre-operative status (acidosis) Pulmonary venous obstruction, small PFO High pulmonary vascular resistance, pre operative SAT 80% Young age Small left ventricle Major associated anomalies Infracardiac or mixed type,Literature:,BuLock FA et al. Balloon dilatation of vein stenosis in obstructed

34、TAPVC. Ped Cardio 1998;15:78 Balloon atrial septostomy: Risk factor for death, not an ameliorating factor. Balloon dilatation of left vertical vein in obstructive supracardiac TAPVC may provide important clinical improvement and short term hemodinamic stability before operation Kiziltepe U et al. Ac

35、ute pulm hypertensive crisis after TAPVC repairtreatment. Internat J of Cardio 2002:87;107-109 Treatment of recurrent severe pulm hypertension refractive to medical treatment can be dealt with inflow occlusion and creation of large intra atrial connection. Chest left open post operatively.,Post oper

36、ative PV stenosis:Stark J, De Leval MR. Management of pulm venous obstruction after TAPVC repair. Eur J Cardio-Thorac Surg. 2003:24:28-36,Complicates surgery in 5-10% Classification of PV stenosis: Discrete stenosis Tubular focal stenosis Diffuse hypoplasia May be severe anastomotic stenosis or pulm

37、onary vein stenosis.,Post operative PV stenosis:,Predominate after correction of Infracardiac and cardiac TAPVC. Vary from Fibrosis and neo-intimal proliferation at the anastomotic site, to segmental or diffuse intimal hyperplasia with extension to the individual pulm veins Abnormal architecture of pulm venous wall leads to increased tendency to neo intimal proliferatio