RVOT Stenting In Infant With TOF

RVOT Stenting In Infant WithTOFBy Dr. Mashail AlobaidanConsultant Interventional Pediatric CardiologistPrince Sultan Cardiac Center, Riyadh, Saudi Arabia3 rd Annual Scientific Meeting Egyptian Working Group for PediatricCardiologists 2010

Tetralogy of Fallot• Maformation first described by Niles Stensenin 1673• Tetralogy of Fallot (ToF) represents aboutTetralogy of Fallot (ToF) represents about6% of all CHD

Characteristic morphologic features• Antero-cephaled deviationof outlet septum• Hypertrophied septoparietaltrabeculation

Variable morphologic features• Extent of aortic override• Right ventricular marginsof VSD• Nature of sub-pulmonaryobstruction• Associated malformations

• Aorta predominantly supported by left ventricle (effectivelyconcordant connection• Aorta predominantly supported by right ventricle ( effectivelydouble outlet connection)

1) Outlet septum2) Septoparietal trabeculation

Coronary abnormality

Tetralogy of Fallot• In this condition the presence and degree ofcyanosis depends on right ventricular outflowtract obstruction andthe degree of pulmonary arterydevelopment.• Tetralogy of Fallot has many anatomicalvariants with different clinical andhemodynamic findings

Treatment Favorable anatomy →Neonatal RepairTreatment of choice in native infundibularstenosis is surgery, as it carries a very low riskand rarely requires reoperation.* Neonatal repair of tetralogy of Fallot has lowmortality (

Treatment• Advantages of primary repair include earlyabolishmentof cyanosis, minimisation of right ventricularhypertrophy and fibrosis, avoidance of leftventricular volume-loadingloading frompalliative shunts and potential reduction indysrhythmias.• Major disadvantage :the neonatal brain may bemore prone to surgery-relatedrelated neurological injury.

Treatment Unfavorable anatomy→Intervention• PDA stenting or• Blalock-Taussig anastomosis is often the first stepof operative treatment in this type of TOF.* This allows for:hypoxia avoidance,satisfactory if oxygen delivery dli andpulmonary artery development untilnext step of surgical treatment.

• In some patients with severe pulmonary arteryunderdevelopment there is no possibility forsystemic-pulmonary anastomosis during the earlylife period, and increasing hypoxemia is life-threatening for these children.• In some other patent ductus arteriosus is absent or withconfluent PA stenosis* Right ventricle outflow tract balloon plasty with ihsubsequent stent implantation can be an alternativemethod of treatment in this group of patients.

• RVOT stenting provides an effectivealternative to palliative surgical enlargement ofthe RVOT.• Re-stenosis causes recurrence of gradients insome cases, but responds to redilatation

• Hausdorf G, Schulze- Neick I, Lange PE.Radiofrequency-assisted “reconstruction” of theright ventricular outflow tract in muscularpulmonary atresia with ventricular septal defect.Br Heart J 1993;69:343–346.• Nakanishi T. Intravascular stents for managementof pulmonary artery and right ventricular outflowobstruction. Heart Vessels 1994;9:40–4848.• Gibbs JL, Uzun O, Blackburn MEC, et al. Rightventricular outflow stent implantation: analternative to palliative i surgical relief ofinfundibular pulmonary stenosis. Heart1997;77:176–179.179.

TOF & PA ….. RF& Stent

STENT IMPLANTATION IN

• Vincent RN, Diehl HJ. Unusual stents in infantswith severe congenital heart disease. J IntervenCardiol 2003;16:189–91.189 91• Laudito A, Bandisode VM, Lucas JF, et al. Rightventricular outflow tract stent as abridge tosurgery in a premature infant with tetralogy ofFallot. Ann Thorac Surg.6–81:744;2006• G Dohlen, R R Chaturvedi, L N Benson, AOzawa, G S Van Arsdell, D SFruitman and K-JLee :Stenting of the right ventricular outflow tractin the symptomatic infant with tetralogy of FallotHeart 2009;95;142‐147

Indications• RV-to-PA conduit stenosis,• Residual infundibular stenosis after intracardiacrepair,• Tetrology of Fallot with hypoplastic branchpulmonary arteries after palliative shunt surgery,• Total intracardiac repair is not possible.• Pulmonary atresia a after perforation o of atreticsegment, and RV hypertrophic cardiomyopathy.• Prematurity and low birth weight remain riskfactors for poor outcome

• Low weight,• Prematurity,• Young age(

Complications• Stent migration,• Ventricular arrhythmias,• Collapse or fracture of the stent• Recurrent stenosis.• Neoendothelial l or muscular proliferation** These can be minimized by limiting thelength of time the stent is left in place.

Blalock-Taussig anastomosis• In comparison with palliation by a systemic-to-pulmonary shunt,- the outflow tract stent avoided the* difficulties of appropriate shunt size selectionin a small patient* placement of a shunt to a hypoplastic branchpulmonary artery and* avoidance of diastolic runoff from the aorta withlower diastolic blood pressure and end-organperfusion,

• pulmonary artery distortion,• phrenic and vocal cord nerve injury,• chylothorax,h• shunt narrowing, or occlusion• overcirculation and left ventricular volumeloading• death.

PDA Stent• Stent implantation in a patent ductus arteriosusmay be an alternative nonsurgical approach toproviding pulmonary blood flow . Compared withstenting the right ventricular outflow tract,* ductal stenting may have the disadvantages of diastolicrunoff from the aorta with lower diastolic blood pressureand end-organ perfusion,* a higher likelihood of neointimal proliferation,* the need for arterial vascular access during placement.* absent ductus arteriosus , tortousity of the ductus arteriosusand presence of confluent pulmonary artery stenosiscontradict PDA stenting

Prince Sultan Cardiac Center- Militaryhospital experience , Riyadh SaudiArabiaDr. Mashail Alobaidan, MD, Jassim, ,abdulhameed, MD, Saad Alyuosef , MD

Prince Sultan Cardiac Center- Military HospitalExperience11 patients who underwent 14 RVOT stentingprocedures from June 2007 to March 2010• Median age 3 month• Mdi Median weight ih 3.5 kg• 7 girls and 4 boys• 10 patients have TOF & PS , 1 has TOF & PA• 3 patients have occluded RBTS

Patients characteristics11 PATIENTS10 patients TOF &PS 1 Patient TOF & PA3 Patients with2 patient has Syndrome &3 had small pulmonary2 with small weight ,occluded RBTMental retardationarteries ,confluent stenosis unamainable PDAstenting

Patients CharacteristicsPatients Diagnosis Age Weight Risk factor1 TOF 89 days 2.8 kg Low birth weight2TOF &Confluent PAStenosis4 mo 3.5 kg3 TOF 87 days 3.5 kg Syndrome4TOF &Confluent PAhypoplasia7mo 5 kg Occluded BTS5 TOF&PA 10 mo 4.2 kg Mental retardation & 2occluded d BTS6 TOF 75 days 2.4 kg Small weight7 DORV& TOF 3 mo 3.4 kg Syndrome8TOF& PA hypoplasia40 days 3.1 kg9 TOF 3 mo 3.5 kg10 TOF 2.5 mo 3.5 kg Occluded BTS11TOF & LPA Stenosis3 mo 3.5

Clinical, echocardiographic, angiographic andhemodynamic data were reviewed* Median pulmonary valve diameter 3.1 mm(range 2.7–5.2), Z-score −5.5 (range −8.9 to−4.4) 4 4)* Median arterial oxygen is 60%(55-66%)* Median RPA Z-score - 3.1 (- 6.2 - -2.1)* Median LPA Z-score is - 4.2 (−7 7.2 to −2.9)

Angio &Echo

Method• Consent were taken• Prograde approach in all patients ( FV & JV)• All patients except 2 were under GA• RV angiography in LAO 30/CR 30• Measurements by angio.were compared to ECHO.• Coronary stent and premounted balloon (genesis)stents were used ( 4-6 mm in size)• Antibiotics were used for 24 hrs

• Heparin was used for 24 hrs and aspirin thereafter• One patient has RF perforation of the muscularatresia followed by Stent implantation.• Patients extubated after procedure• Post procedure echo & before discharge & 6wks and 3 mo later was done

Conclusion In properly selected cases, RVOT stenting can beused as a palliative procedure with gratifyingresults. RVOT stenting is usually indicated in caseswhere total intracardiac repair is not possible. Total intracardiac repair can be achieved thereafter , and the surgeons do not anticipate problemsin cutting across the stent to widen the RVOT.

Pi Prince Sultan Cardiac Center –Riyadh, Saudi Arabia