Presentation on theme: "Pulmonary Stenosis Seoul National University Hospital"— Presentation transcript:
1 Pulmonary Stenosis Seoul National University Hospital Department of Thoracic & Cardiovascular Surgery
2 Pulmonary Stenosis and Intact Ventricular Septum 1. DefinitionA form of right ventricular outflow tract obstruction in whichstenosis is usually valvar or infundibular, or both ( rarely,supravalvar )* Simple, pure, isolated pulmonary valvar stenosis(70%)* Pulmonary stenosis with normal aortic root2. HistoryDoyen : 1st attempt of surgical relief in 1913Sellors : Closed transventricular instrumental valvotomyrepair in 1947Brock : Closed valvotomy in 1948Swan : Open correction during circulatory arrest in 1952Kan : Percutaneous balloon valvuloplasty in 1982
3 Pulmonary Stenosis and Intact Ventricular Septum PathophysiologyUsually involves a stenotic valve that obstructs right ventricular empting and pulmonary blood flow, producing right ventricular hypertrophy and cyanosis.Subvalvar and supravalvar stenosis are other forms of this defect.
4 Pulmonary Stenosis and Intact Ventricular Septum Patterns of pulmonary stenosis1. Critical valvar pulmonary stenosisin neonates2. Pulmonary stenosis in infants,children, & adults
5 Critical PS in Neonates Morphology1. Pulmonary valveUniform fibrous conePulmonary valve dysplasia2. Pulmonary arteriesHypoplastic in 50%3. Right ventricleMild to moderately reducedRarely severely reducedConcentric ventricularhypertrophyDiffuse fibrosis4. Tricuspid valveNormal dimension in 50%Severe hypoplasia in 10%5. RV-Coronary A. fistulae2% have fistulae10% have sinusoids6. Right atriumUsually large, at least PFO7. Coexisting cardiac diseasesUncommonEbstein anomaly in 1%
6 Clinical Features & Diagnosis Critical PS in Neonates1. Critically ill, irritable, tachypneic, hypoxic2. Tachycardia & heart failure, tricuspid insufficiencymay be present3. Chest X-Ray, EKG show less evidence4. Echocardiography, cardiac catheterization,cineangiography provide precise information.5. Tricuspid valve is competent in 10% & the other90% show incompetence.
7 Critical PS in Neonate Natural History 1. Presentation is nearly always within 1st 2 weeks of life.2. All neonates in whom severe hypoxia develops diewithout treatment, although some may live for a fewmonths.
8 Operation for Critical PS Critical PS in NeonateOperation for Critical PS1. Percutaneous balloon valvotomy2. Open pulmonary valvotomy using CPB3. Transannular patch4. Systemic-pulmonary artery shuntmm PTFE graft in case of PaO2less than 30mmHg after CPB
9 Critical PS in Neonate Special features of postoperative care 1. PGE1 intravenously preoperatively and earlypostoperatively to maintain ductal patency2. Infants should be restudied at monthsof age if systemic-pulmonary artery shunt has beenperformed .3. In about 10% of patients, follow-up evaluationindicates important residual right ventricularhypertension.
10 Critical PS in Neonate Surgical Results 1. Survival Early death ; less than 10%Time-related survival2. Modes of deathHypoxiaAcute cardiac failure3. Incremental risk factorsfor premature deathRV enlargement(cardiomyopathy)Reduction of cavity sizewithout shunt4. Reintervention5. Residual RVOTO6. Morphologic & functionalchanges after valvotomyRV cavity is normal or mildlyreduced in 90%.More than 80% of patients ;no tricuspid incompetence
13 Critical PS in Neonate Indications for operation 1. Interventional treatment is indicated for all neonates.2. Severe hypoplasia of the pulmonary annulus ( z < -4)& severe reduction of RV cavity size; a transannularpatch & concomitant systemic-pulmonary artery shuntare indicated in 10-20% of patients as initial procedure.3. In patients who fail to develop adequate oxygen level(more than 85% ) & RA pressure (less than 12-15mmHg)at rest with atrial septum and shunt temporally closed,Fontan operation is ultimately indicated.
14 PS in Infants, Children, Adults Morphology1. Pulmonary valveBetter developed than in neonatesCommissural fusion ; deformed,thickened, myxomatous,Secondary infundibular stenosis in olderpatients2. Pulmonary arteryPoststenotic dilatation in 70%3. Right ventricleUncommon hypoplasiaThickening of RV wall10-20% have only infundibular stenosis4. Tricuspid valveUsually morphologically normal5. Right atriumWall is hypertrophiedPatent foramem ovale in most6. Left ventricleIdiopathic hypertrophic subaorticstenosis (Noonan syndrome)Altered left ventricular geometryaffect ventricular function (revertto normal after correction)7. Associated anomaliesNoonan’s syndromeIntrauterine rubellaNeurofibromatosis
15 Clinical Features & Diagnosis PS in Infants, Children, Adults1. SymptomsSymptomatic, but less severe than neonates30-40% are asymptomatic.Effort dyspnea & cyanosis may appear.2. SignsSystolic murmur with a thrillPulmonary component of second sound is decreased.3. ElectrocardiographyRAE, RAD, RVHT- waves in right precordial lead4. Echocardiography, catheterization & cineangiography
16 Pulmonary Stenosis with IVS Natural History1. Incidence8~10% of CHDSlightly predominance of females2. Patients presenting in infancyWide variation of obstruction (mild stenosis in 40%,moderate 47%. Severe 14%)3. Patients presenting after infancyPressure gradient less than 25mmHg rarely progress.4. Effect of right ventricular hypoplasia14% of PS have varying degree of hypoplasia &left untreated, affect unfavorably
17 Techniques of Operation PS in Infants, Children, Adults1. CommentPercutaneous balloon valvotomy is treatment ofchoice for valvar pulmonary stenosis, if not possible,open surgical valvotomy is indicated.2. Open operation during CPBPulmonary valvotomyInfundibular resectionTransanular patch
20 Special Features & Postoperative Care PS in Infants, Children, Adults1. Withdrawl pressure tracing 24 hrs after operation2. Known tendency for infundibular hypertrophyto regress with time3. When the RV is severely hypoplastic, symptoms andsigns are substantially altered, and when they appearthey tend to progress more rapidly.4. Pulmonary stenosis with RV hypoplasia is associatedwith less than the expected degree of RV hypertrophy.5. Balloon valvotomy may not be as effective, & surgicalapproach may be required in RV hypoplasia group.
21 Indications for Operation of PS PS in Infants, Children, Adults1. When patients first show signs & symptoms, at one ormore months of age, pulmonary valvotomy is advisable.2. Intervention is advised in asymptomqatic infants withsevere stenosis.3. In those with moderate stenosis, intervention is debatable,when stenosis is mild, not recommended.4. In older patients, management differs only in the groupwith moderate stenosis.5. The presence and degrees of RV hypoplasia are takeninto account when deciding upon intervention.
22 Surgical Results of PS with IVS PS in Infants, Children, Adults1. SurvivalEarly deaths ; near zeroRV hypoplasiaAdvanced chronic CHFTime-related survival2. Complete relief of PS3. Reoperations4. CyanosisWhen PFO or residual ASDwith impaired compliance,& hypoplastic RV5. Pulmonary incompetence6. Morphologic changesRV enlarges and becomesnormal size in mostTricuspid incompetence isusually absent late postop.7. Functional CapacityExcellent late resultInferior in hypoplasic ventriclePersistent, recurrent RV failure