Tetrology of fallot corrective surgeries
Download as PPTX, PDF7 likes1,550 views
This document outlines the historical development, goals, evaluation, decision making, surgical procedures, and complications related to corrective surgeries for Tetralogy of Fallot. It discusses the first corrective surgery in 1954 using controlled cross circulation and developments since including use of cardiopulmonary bypass. Evaluation involves understanding the morphology of the right ventricular outflow tract, ventricular septal defect, and pulmonary arteries. Surgical approaches include transventricular, transatrial/pulmonary, and transaortic. Key steps involve resection of septal and parietal muscle bands, pulmonary valvuloplasty, and ventricular septal defect closure. Post-operative management and complications are also covered.
Tetrology of fallot corrective surgeries
- 1. Tetralogy of Fallot CORRECTIVE SURGERIES
- 2. OUTLINE • HISTORICAL DEVELOPMENT • GOALS OF CORRECTIVE SURGERY • INDICATION • EVALUATION AND UNDERSTANDING THE MORPHOLOGY • DECISION MAKING • SURGERY – • INTRAOP EVALUATION • POST OPERATIVE EVALUATION • POST OPERATIVE MANAGEMENT –PRE OP CHECKLIST -PROCEEDINGS -APPROACHES -STEPS - TACKLING OTHER ASPECTS -IMMEDIATE -EARLY -LATE -EARLY MORTALITY -LATE MORTALITY -SURVIVA; -AIIMS EXPERIENCE • COMPLICATIONS • RESULTS • INDICATIONS OF REOPERATION • SPECIFIC ASPECTS IN INFANTS AND ADULTS • SPECIFIC CONCERNS • IDEAL TOF REPAIR • VARIANTS
- 3. ERAs of TOF Anatomical era Era of clinicophysiology and surgery Infant era Current era of cardiac development
- 4. HISTORICAL DEVELOPMENT FIRST CORRECTIVE SURGERY WALTON C LILLEHEI 31 APRIL,1954,CONTROLLED CROSS CIRCULATION. UNIVERSITY OF MINNESOTA. PATCH ENLARGEMENT OF RVOT , 1957 FIRST CORRECTIVE SURGERY USING CPB , KIRKLIN AND COLLEAGUES , IN 1955 MAYO CLINIC TRANS ANNULAR PATCH, 1959
- 7. CONTRIBUTIONS TRANSATRIAL REPAIR HUDSPETH, 1963 NON VALVED PROSTHETIC CONDUIT KLINNER, 1963 RV -> PULMONARY TRUNK CONDUIT LILLEHEI, 1965 VALVED AORTIC HOMOGRAFT CONDUIT ROSS & SOMERVILLE, 1966 UNDER DHCA BARRATT-BOYES AND NEUTZE, 1967 EARLY REPAIR IN INFANTS CASTANEDA, 1977
- 8. GOALS OF CORRECTIVE SURGERY Eliminate intracardiac shunt Reduce RV pressure and volume to normal Preserve normal myocardial function 1. RELIEVE RVOTO 2. COMPLETETE CLOSURE OF VSD RESTORE CIRCULATION TO NORMAL
- 9. INDICATION A DIAGNOSIS OF TOF IS AN INDICATION IN ITSELF PALLIATIVE PROCEDURE VS CORRECTIVE SURGERY AT PRESESNTATION ( WHEN TO DO AND WHEN NOT TO DO ) WHEN TO DO WHAT TO DO HOW TO DO
- 10. PRE OPERATIVE EVALUATION HISTORY CLINICAL EXAMINATION CXR ECG ECHO CATH STUDY CT/MRI HEMATOLOGICAL AND BIOCHEMICAL EVALUATION
- 11. UNDERSTANDING THE MORPHOLOGY RVOT VSD AORTA PULMONARY VALVE, PA, MAPCAs CORONARIES OTHER ASSOCIATED ANOMALIES
- 12. Morphological classification of RVOTO ISOLATED INFUNDIBULAR STENOSIS INFUNDIBULAR + VALVULAR STENOSIS DIFFUSE RT VENT OUTFLOW HYPOPLASIA DOMINANT VALVAR STENOSIS
- 13. VSD UNDERSTANDING THE MALALIGNMENT NUMBER SITE,SIZE, SHAPE,MARGINS OF VSD
- 14. TYPE OF VSD
- 15. AORTA AORTA IS BV IN ORIGIN MORE ANTERIORLY PLACED SOME DEGREE OF ANNULAR ROTATION (CLOCKWISE) DILATED AORTIC ROOT ARCH
- 16. TO LOOK FOR VENOUS DRAINAGE DUCTUS VENTRICLES (SIZE, eDV, DYSFN) VALVES (MV,TV Z SCORES) CORONARY ARTERIES ANY OTHER ASSOCIATED DEFECT
- 17. UNDERSTANDING THE PAs AND MAPCAs PULM0NARY ANNULUS EVALUATION ( Z SCORE) PULMONARY VALVE ASSESSMENT OF PAs - MC GOON RATIO NAKATA INDEX TOTAL NEOPULMONARY INDEX
- 18. FULL SIZE , HALF SIZE
- 19. MCGoon ratio 1. This is the ratio of = diameters of immediately pre-branching left +right pulmonary arteries / descending aorta just above level of diaphragm 2. Normal value more than 2 to 2.5 3 TOF patients undergoing total correction should have McGoon ratio more than 1 4. Good Fontan candidate should have McGoon ratio more than 1.8 PA size
- 20. Nakata index 1. Nakata index is Cross sectional area of left and right pulmonary artery in mm2 divided by total body surface area (BSA) 2. Left and right pulmonary arteries are measured just before first lobar branching. 3. Cross sectional area is measured by ( 𝜋𝑟2 x magnification coefficient, expressed for body surface area) 4. Normal - 330 +/- 30 mm2/BSA 5. TOF with PS ≥ 100 mm2/BSA for total correction. 6. Good Fontan Candidate should have index more than 250 mm2/BSA
- 21. Total neopulmonary index Aortopulmonary collateral index + NAKATA INDEX Aortopulmonary collateral index = CSA of all significant APCs summated and divided by BSA TNPAI ≥ 250 suitable for ICR
- 22. AORTO PULMONARY COLLATERALS Significant collaterals – Size larger than 3mm Size equal to or bigger than IMA Tortuosity Early Filling of central Pas Problems due to MAPCAs INTRAOP Warming, LV distension, cardioplegia wash out POST OPERATIVE Flooding of lung fields Hemoptysis
- 23. Considerations after palliative procedure :- Shunt location Shunt patency Shunt/conduit related complications Collaterals
- 24. TYPE OF COLLATERALS DUCTUS ARTERIOSUS SYSTEMIC ARTERIAL COLLATERALS PLEURAL ARTERIAL PLEXUS -DTA TO PA -BROCHIAL ARTERIAL COLLATERALS -INDIRECT SYSTEMIC ARTERIAL
- 25. Decision making in TOF UNDERSTANDING THE MORPHOLOGY- VARIANTS PALLIATION • DIAGNOSIS WITH FAVOURABLE ANATOMY • HYPOLASTIC PAs • WT <2.5KG, AGE< 3-4 MONTHS (RECURRENT HYPOXIC SPELLS) • TOF+PA • UNFAVOURABLE CORONARY ARTERY ANATOMY • MULTIPLE VSDs TIMING – NO CONCLUSIVE EVIDENCE CORRECTIVE SURGERY
- 26. FOR ICR. Mc Goon ratio > 1 Nakata Index >100 TPNAI ≥ 250 Z value > -3 , CI if < -7 LV Volume 60% or more than normal (30 ml/m2) Absent peripheral pulmonary stenosis No major coronary branch crossing RVOT
- 27. Not in favour of Early ICR and Plan Unfavourable PA anatomy in infant Multiple VSD in infant Coronary artery crossing RVOT in infant Hypoplastic LV (LVEDV < 30 ml/m2, MV < -2 ‘Z’, Pulmonary annulus < -7 ‘Z’) Associated comorbidities (Tracheo-esophageal fistula) Institutional criteria for performing ICR at a particular age & weight
- 28. PREOP CHECKLIST. 1. Prior palliative operations: systemic to pulmonary artery shunt, branch pulmonary artery augmentation 2. Anatomy of the VSD, any additional VSDs 3. Degree and level of RVOTO 4. Nature and size of the pulmonary valve annulus size 5. Size and distribution of branch pulmonary arteries 6. Coronary artery distribution 7. Presence of an atrial level shunt 8. Any associated defects
- 29. MANAGEMENT OF AORTOPULMONARY COLLATERALS CATHETER BASED EMBOLIZATION GIANTURCO WIRE COILS: Stainless steel wire GEL-FOAM SURGICAL LIGATION OF MAPCAS UNIFOCALIZATION
- 30. ASPECTS OF TOF SURGERY PRE OPERATIVE PREPARATIONS IN THEATRE ACCESS PERICARDIUM LOCATION OF SHUNT AND SHUNT TAKEDOWN APPROACH RESECTION/DIVISION OF SEPTAL AND PARIETAL MUSCLE BANDS TAP RCA BRANCHES ANOMALOUS LAD APPROACHING ABNORMAL PV CUSP ASD AND PFO TRICUSPID VALVE
- 31. PROCEEDINGS :- Use Hemostat - Keep warm banked blood ready to tackle the blood loss during sternotomy Intubation, Securing lines , temperature, NIRS and spo2 probes Catheterization , cautery pad Check lines and equipment Warming blankets Positioning, painting, draping Intraop TEE
- 32. Access - Midline Sternotomy Thymus dissection and identifying innominate vein Prepare pericardium. Take purse String – for safety AORTA-PA dissection, PA branches dissection Dissect shunt Lt side – Lt. Pleura- Rt. Side – Between SVC & Aorta, Behind SVC Dissection of ductus /ligamentum - Aortic cannulation -SVC/RAA cannulation - IVC cannulation Go on CPB, Do not cool, keep ejecting, down on flows
- 33. Ligate / clip the shunt- LV vent to avoid distension/manage venous return. Division of ductus Cooling – moderate hypothermia Cardioplegia canula Cross clamping Cardiac arrest
- 34. APPROACHES TRANS VENTRICULAR TRANS RA/RA-PA TRANS RA-RV TRANS AORTIC
- 35. TRANS VENTRICULAR APPROACH RVOT INFUNDIBULOTOMY • GOOD ACCESS TO VSD • ALL AGE GROUPS • EASY TO PLACE A PATCH AND ACCESSIBILITY • EASY TO LEARN AND DEMONSTRATE
- 37. • MYOCARDIAL INJURY • CORONARY INJURY - ARRHYTHMIAS - RV DYSFUNCTION • PULMONARY VALVE INSUFFICIENCY LEAVING AN ASD The Effects of Cardiac Bypass and Ventriculotomy Upon Right Ventricular Function; With Report of Successful Closure of Ventricular Septal Defect by Use of Atriotomy G R STIRLING, P H STANLEY, C W LILLEHEI PMID: 13529648
- 38. MODIFIED TRANSVENTRICULAR REPAIR MAVROUDIS AND BACKER – INFUNDIBULOTOMY + ENLARGEMENT OF PULMONARY SINUSES BACHA AND COLLEAGUES – LONGITUDINAL RIGHT VENTRICULOTOMY + BALOON VALVOTOMY
- 39. TRANS RA/RA-PA
- 41. TRANS ATRIAL/PULMONARY • INTERVEINING PALLIATION (TOF +PA) • LIMITED VISUALIZATION • TRACTION INJURY TO TV AND CONDUCTION TISSUE • OPERATIVE TIME LONGER • DIFFICULT TO TEACH
- 43. Right atriotomy from RAA TO IVC parallel to AV groove Left atrium was vented either through the patent foramen ovale or through the right superior pulmonary vein in older patients. Three everting stay sutures are placed, one each on right atrial free wall, just away from tricuspid annulus at base of right atrial appendage and at acute margin of the heart. The anterior leaflet and the anteroseptal commissures are retracted with curved retractors and internal anatomy is inspected. The size and margins of VSD are defined in relation to the aortic valve, septal leaflet of tricuspid valve and the infundibular ostium. THROUGH TRANS RA/RA-PA APPROACH
- 45. RVOT RESECTION PARIETAL EXTENSION OF SEPTUM DIVIDED ANY OBSTRUCTIVE TRABECULAR EXTENSION LEFTWARD MAY BE EXCISED OS – INFUNDIBULUM- FIBROSIS ALL AROUND EXCISED, MAY BE EXTENDED TO PV DIFFUSE RVOT HYPOPLASIA * • PAPILLARY MUSCLES TO BE PROTECTED • MODERATOR BAND TO BE PROTECTED • PERFORATION OF FREE WALL
- 48. Care while excision of the RVOT muscle Septal side: take care for - Can create a new VSD - Damage to papillary muscle to ATL AND 1st septal artery Parietal side: - If excess shaved, there will be no margin for suturing Crista: - Damage to RCC - If scissor inserted across the VSD (in case of infundibular atresia- damage to AV/ VSD may get enlarged.
- 49. Good coring of the RVOT has been done if: Following structures can be visualized From PA - Complete VSD - Tricuspid valve - Apex of RV From RA - Pulmonary valve - AV across the VSD.
- 50. Pulmonary valvotomy – THOUGH RA - the pulmonary valve is visualized, its cusps are pulled down, everted and valvotomy performed. - The pulmonary annulus is now calibrated and it is preferable to pass the Hegar’s dilators two sizes more than that indicated in Rowlatt’s chart as the heart is under cardioplegic arrest. THROUGH PA - Arteriotomy avoiding annulus - Valvotomy by releasing commissural fusion - Thickened cusp edges may be excised - Decision of TAP, RVOT reconstruction
- 51. VSD CLOSURE Can be performed before/after parietal band excision – closure before defines boundaries and protects Aorta and crista. Dacron/ PTFE/ Glutaraldehyde treated pericardium Interrupted/combined prolene sutures Inferior and anterosuperior sutures to be 5mm away from rim
- 56. Transannular Patching Pre operative assessment - Z score ( -3) ( between -2 to -4, intra op assessment) - Asian type TOF Intra operative assessment - Hegar dilator - LPA stenosis - Bifurcation stenosis - Fibrosed annulus Post operative -Fixed RVOTO • Material used – tissue, synthetic • Extent of incision should not leave any distal narrowing • Damage to left phrenic and left SP vein should not take place
- 57. Materials used for patch TISSUE - Autologous pericardium - Autologous glutaraldehyde treated pericardium - Homograft pericardium/arterial wall - Xenograft – bovine,porcine ARTIFICIAL - Ptfe - ePtfe - DACRON - Collagen impregnated polyester The dimensions should be; Length 1 1/2 times the incision length Width should be according to hegar size for particular weight ( Z VALUE 0 TO +2) NEWER AGENTS -decellularized bovine pericardium -ECM - TISSUE ENGINEERED PATCHES
- 58. Talwar S, Selvam MS, Rajasekhar P, Ramakrishnan S, Choudhary SK, Airan B. Polytetrafluoroethylene patch versus autologous pericardial patch for right ventricular outflow tract reconstruction. J Pract Cardiovasc Sci 2016;2:175-80.
- 59. TAP outcomes CONCERNS REGARDING CHRONIC PULMONARY INSUFFICIENCY Concept of monocusp implantation with TAP – PTFE monocusp, pericardial monocusp, valved grafts
- 60. 0.1 mm ePTFE
- 62. LPA Stenosis
- 63. RPA STENOSIS
- 65. Tricuspid Valve Tethering of the septal leaflet and distortion of chordal structures during VSD closure Valve competency should be tested routinely after VSD closure. If regurgitation is present, tricuspid valve repair should be performed. Partial closure of the anterior septal leaflet commissure is effective in restoring tricuspid valve competency when septal leaflet tethering is present. A competent tricuspid valve is critical to achieving excellent outcome, especially if a transanular patch is used.
- 66. Management of Atrial septum ASD/PFO Usually closed In infants with TAP, PFO left open In conditions where TAP done with increased Rp , PFO left open Where PR and early RV dysfunction suspected, PFO left open
- 67. 1. If PA size & annulus adequate sized - RA-PA approach (Hudspeth) 2. Elective LIMA- LAD anastomosis (Cooley) 3. Turn the flap of anterior pulmonary artery to the ventriculotmoy & suture and additional patch over this PA flap (Van Son) 4. Mobilization of the coronary artery & suture patch beneath the lifted coronary(Boncheck) 5. Two-patch techniques: transannular oblique patch and infundibular patch (below the anomalous coronary artery) 6. Use of conduit 7. Central shunt MANAGEMENT OF ANOMALOUS CORONARY
- 69. INTERA OPERATIVE ASSESSMENT P RV/LV ANY FIXED/DYNAMIC RVOTO RESIDUAL VSD
- 70. Post repair p RV/ LV > 0.7 <0.7 TRANS ANNULAR PATCH NOT PLACED PLACED Between sinus portion of RV & patch RESIDUALGRADIENT CPB RE-INSTITUTED CORRECTION LOCALIZED CAUSE NO CORRECTEABLE CAUSE Haemodynamics & general condition GOOD NOT GOOD HIGH RA PRESSURE CPB TRANS ANNULAR PATCH Fenestration of VSD patch Spontaneous improvement in few hours
- 71. Drawbacks In neonates and young infants it is not a reliable predictor - Data of this ratio derived from study in adults to predict outcome - They have reduced SVR post operatively which normalizes
- 72. Post operative management TO GIVE ADEQUATE TIME FOR NORMAL CONVALSCENCE INOTROPIC SUPPORT AND REDUCE AFTERLOAD RA PRESSURE MONITORING MAINTAIN ADEQUATE HEMATOCRIT LOOK FOR BLEEDING LOOK FOR ARRHYTHMIAS
- 73. IMMEDIATE COMPLICATIONS PATIENTS HAVE TENDENCY TO RETAIN FLUID –INTERSTITIAL/PLEURAL/PERICARDIAL LOW ARTERIAL BLOOD PRESSURE ARTERIAL DESATURATION LEFT AND RIGHT ATRIAL PRESSURE ( ANY SHUNTS) - PLA>PRA ->SHUNT L->R -PRA>PLA -> SHUNT R->L BLEEDING CONDUCTION DEFECTS /ARRHYTHMIA (RBBB,CHB, JET)
- 74. EARLY COMPLICATIONS RESIDUAL RVOTO- usually within a year RV ANEURYSMS – develop within 6 months RECURRENT/RESIDUAL VSD – very rare
- 75. RV FUNCTION Factors deciding post repair RV function are Pre op status of ventricle Extent of RT Ventriculotomy Extent of muscle resection Preservation of coronaries Residual RV systolic hypertension Pulmonary regurgitation* Thus a Trans Annular Patch is associated with poorer RV function Low RV EF High RV ED volume
- 76. LV FUNCTION Post repair LV function is variable. Risk factors for poor LV function include Older age at Repair Pre repair Shunting causing LV Volume overload Residual / Recurrent Defects Age at Repair which is associated with normal LV function is not defined 2-3 Years by some 10 Years by some
- 77. Late Problems ANATOMIC RIGHT HEART • Pulmonary Regurgitation (PR) • RVOTO-Infundibular - distal PA’s • Residual VSD/Missed VSD/Patch Dehiscence • RVOT aneurysm • Conduit related problems LEFT HEART – AR, Aortic root dilatation RESIDUAL SHUNTS PHYSIOLOGIC •RV dysfunction •Restrictive RV physiology •LV dysfunction Conduction Rhythm •Ventricular arrhythmias Sudden death • arrhythmias • BBB- Late CHB
- 78. PULMONARY VALVE MANAGEMENT IN TOF - CONVENTIONAL AND CONTEMPORARY MANAGEMENT
- 79. INTERVENTION - WHY AND WHEN THE SHIFT OF GOALS LONG TERM OUTCOMES WITH TAP AND FREE PR - IMPACT ON RV FUNCTION, MORBIDITY AND SURVIVAL – understanding the interplay of young age + diificult anatomy / small annulus/need for TAP and p RV/LV PREVENTIVE – INTRA OPERATIVE THERAPEUTIC – POST OPERATIVE
- 80. • 1989, SOCIETY OF THORACIC SURGEONS • 1967- May 1986, 814 patients • Transannular patching was a risk factor for death early after repair of tetralogy of Fallot but not thereafter • There are no risk factors (including transannular patching) for declining functional status in surviving patients • Transannular patching clearly was a risk factor for reoperation for pulmonary regurgitation. However, the strength of its effect was dependent on the postrepair (OR) PRV/LV
- 81. • JTCS, 2001 • Jan 1972- Dec 1977, 57 pts (< 24 months) • In this study, long-term survival of patients after transannular repair was equivalent to that of patients with anulus- sparing repairs, implying that the use of a TAP resulted in neutralization of this risk factor. • Our study showed no significant difference in need for reintervention between patients with or without a TAP, although the incidence of RVOT obstruction was significantly lower in those who had a TAP.
- 82. • EUROPEAN JOURNAL OF CARDIOTHORACIC SURGERY , 2014 • Finland population based study , 1962-2007, 600 pts • we have demonstrated that the need of the TAP is associated with a higher risk of reoperation • . In our study group of 600 patients with over 40-year follow-up, however, no effect on late mortality was seen in response to the need of TAP.
- 83. Romeo JL, Etnel JR, Takkenberg JJ, Roos-Hesselink JW, Helbing WA, van de Woestijne P, Bogers AJ, Mokhles MM. Outcome after surgical repair of tetralogy of Fallot: A systematic review and meta-analysis. The Journal of Thoracic and Cardiovascular Surgery. 2020 Jan 1;159(1):220-36.
- 85. Outcome after surgical repair of tetralogy of Fallot: A systematic review and meta-analysis The overall temporal trend of the use of a TAP has remained stable, around 50% during the last 50 years TAP is not a risk factor itself but indicates a more difficult and hazardous anatomy to begin with. Freedom from pulmonary valve replacement was significantly lower in patients who received a TAP Strategies - Introducing a strategy of restrictive annular enlargement in the University Hospital of Schlesweig-Holstein in Germany led to a lower TAP rate without an increase in residual RVOT obstruction or reintervention rate. Hua and colleagues43 used a cut-off z-score of >–3 and successfully avoided a TAP in 95% of their patients Romeo JL, Etnel JR, Takkenberg JJ, Roos-Hesselink JW, Helbing WA, van de Woestijne P, Bogers AJ, Mokhles MM. Outcome after surgical repair of tetralogy of Fallot: A systematic review and meta-analysis. The Journal of Thoracic and Cardiovascular Surgery. 2020 Jan 1;159(1):220-36.
- 86. Management of pulmonary valve Intra-operative Post-operative Annulus sparing Trans annular repair PVR PVR Native pulmonary valve reconstruction
- 87. INTRA-OPERATIVE MANAGEMENT TRANS ANNULAR REPAIR - Homograft monocusp reconstruction - Pulmonary cusp patch reconstruction (E.Bacha) - Monocusp ptfe pulmpnary valve (Brown, INDIANA) - Bicuspid PTFE pulmonary valve (florida technique) - Hand sewn PTFE valve (Graham nunn technique, Austrailia) - Pulmonary cusp and annular extension technique(Japan) - Annular enlargement with valve repair (Snug, korea) ANNULUS SPARING -Trans RA/PA/RA-PA repair ( Hudspeth) -Infundibulotomy + enlargement of sinuses ( C.Marvoudis) -Commisurotomy +/- rigid bougie dilation (E.Bacha) -Commisurotomy + intraoperative balloon dilatation (E.Bacha) -Leaflet delamination (G.Stellin)
- 90. A retrospective review of all patients less than 18 years of age undergoing a PHM RVOT reconstruction at Childrens Hospital Los Angeles from February 1996 to December 2007 was performed 2010, THE SOCIETY OF THORACIC SURGEONS • CONCLUDED EARLY IMPROVED OUTCOMES • COST FACTORS • IMMUNIGENICITY • AVAILABILITY
- 91. • STS, 2006 • Jan 2000- July 2005, 860 total patients, 334 patients underwent trans atrial repair • Age group 6 months to 40 years • Favorable cardiac anatomy was defined as discrete infundibular obstruction with adequate pulmonary annulus and good-sized branch pulmonary arteries. All Z-values upto - 3 were considered suitable for transatrial approach. • Absolute contraindication for the trans–right atrium correction was the need for the enlargement of the pulmonary annulus or pulmonary arterioplasty as judged by echocardiography and cineangiography. • Only 5 of our patients had low output syndrome. In all 5, a residual surgical problem could be identified, and there was no evidence of primary right ventricular dysfunction. • By avoiding the use of an outflow patch, we have had very low incidence of severe pulmonary regurgitation (6 of 296; 2%).
- 92. Infundibulotomy + enlargement of sinuses ( C.Marvoudis) All patients undergoing repair of TOF between January 1997 and July 2004 at our institution were identified from our computerized patient database 102 patients Ann Thorac Surg , 2005
- 93. If there was evidence of residual subvalvar, valvar, or supravalvar stenosis after the transatrial resection, then a longitudinal pulmonary arteriotomy was made and the incision carried into both the right and left sinuses on a tricuspid and vertically oriented bicuspid valve (Fig 1A) or into the anterior sinus on a horizontally oriented bicuspid valve. The infundibulum was inspected through the pulmonary valve and additional resection performed if necessary. The typical length of the infundibular incision was 15 to 20 mm and was closed with a Gore-Tex patch. The pulmonary arteriotomy was patched with autologous pericardium cut to form a pantaloon patch in cases in which the arteriotomy was carried into two sinuses Stewart RD, Backer CL, Young L, Mavroudis C. Tetralogy of Fallot: results of a pulmonary valve-sparing strategy. The Annals of thoracic surgery. 2005 Oct 1;80(4):1431-9.
- 94. Infundibulotomy + enlargement of sinuses ( C.Marvoudis)
- 95. In every case, one should always aim to completely relieve the subvalvar and supravalvar areas by: - Doing a complete infundibular muscle resection, including the area just under the annulus (either via limited infundibulotomy or via transatrial/transpulmonary). - - Unless well-developed MPA, MPA longitudinal incision from annulus to exact midpoint of distal MPA/PA bifurcation, and patch augmentation. - - There is often an under-appreciated element of supraPS, with the sinotubular junction of the posterior sinus being narrowed. This can be dealt with either with a separate small patch or with partial-thickness incisions to the media of the vessel wall (without breaching the adventitia). Bacha E. Valve-sparing options in tetralogy of Fallot surgery. InSeminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual 2012 Jan 1 (Vol. 15, No. 1, pp. 24-26). WB Saunders.
- 96. - Commisurotomy +/- rigid bougie dilation (E.Bacha) - Commisurotomy + intraoperative balloon dilatation (E.Bacha) - Pulmonary cusp patch reconstruction (E.Bacha)
- 97. Commisurotomy +/- rigid bougie dilation (E.Bacha) This is the simplest technique, and is used in cases of mild to-moderate PS with little pulmonary valve dysplasia, As always, a pulmonary valve commissurotomy into the media layer is performed . Hegar dilators or balloons are serially inserted, aiming for 1 to 2 mm higher than the calculated normal pulmonary annular size. Bacha E. Valve-Sparing Options in Tetralogy of Fallot Surgery. Operative Techniques in Thoracic and Cardiovascular Surgery. 2013 Dec 1;18(4):316-27.
- 98. Commisurotomy + intraoperative balloon dilatation (E.Bacha) • This technique is best reserved for moderate PS with moderate cusp dysplasia • After commissurotomy, the effective valve orifice is sized with a Hegar dilator (without dilation). • Starting with a balloon 1 mm larger than the Hegar size that slipped through the valve easily, the balloon is inserted either via the infundibular incision or via the unopened RVOT transatrially and inflated by hand. • The inflation is monitored visually, as one can see the stretching of the cusps and annulus. The balloons are gradually increased in size by 1-mm increments.
- 99. Pulmonary cusp patch reconstruction (E.Bacha) The pulmonary cusp patch reconstruction technique can be used even in severe PS The annulus and anterior cusp are divided as for a transannular patch, leaving equal cusp remnants on each side. The tethering of the anterior cusp to the MPA is left untouched to preserve hinge function of the newly created large anterior cusp Native pericardium can be used as patch material, but also 0.1 mm polytetrafluoroethylene (PTFE) or extracellular matrix (ECM)
- 100. The patch is sutured to each cut cusp edge, leaving 1 to 2 mm protruding over the free edge of the valve. Caudally, it can be sutured at the level of the pulmonary annulus to the other “transannular” patch that covers the entire RVOT, or it can be sutured to the cut edge of the infundibulotomy. The 2D patch then covers the entire incision, from distal MPA to proximal RVOT
- 101. Pulmonary cusp patch reconstruction (E.Bacha)( VSTAR)
- 102. Results – JTCVS, 2017 • Patients with ToF-PS who undergo valve-sparing repair with IBD develop progressive PR. Compared with traditional TAP repair, the timing and extent of RV dilation appears similar for patients who have undergone valve-sparing repair with IBD. • In patients with significant annular hypoplasia, and those younger than 3 months of age at repair, alternative surgical approaches should be explored
- 104. • We have been surprised at the higher than expected proportion of VSTAR patients who have developed PR at long term, but are comforted in that these patients traditionally would have all had TAPs anyways • . Also, none of the VSTAR patients have required a reoperation to date
- 105. Leaflet delamination (G.Stellin) The recent introduction of delamination PV plasty allows the extension of the cusp’s coaptation surface, which is important for achieving acceptable PV competence.
- 107. Your text here Leaflet delamination (G.Stellin) Vida VL, Guariento A, Zucchetta F, Padalino M, Castaldi B, Milanesi O, Stellin G. Preservation of the pulmonary valve during early repair of tetralogy of Fallot: surgical techniques. InSeminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual 2016 Jan 1 (Vol. 19, No. 1, pp. 75-81). WB Saunders.
- 108. Mid term results :- According to our mid-term results, preservation of the PV was possible in almost half of the cases of repaired TOF treated in our institution since 2007. These results were optimal in patients with a Z score of 3 or higher Recently, however, we extended the application of this technique to patients with a PV Z score down to 4. The smaller the annulus, the more frequently lesions on the PV were observed. Vida VL, Guariento A, Castaldi B, Sambugaro M, Padalino MA, Milanesi O, Stellin G. Evolving strategies for preserving the pulmonary valve during early repair of tetralogy of Fallot: mid-term results. The Journal of thoracic and cardiovascular surgery. 2014 Feb 1;147(2):687-96.
- 109. PTFE Monocusp Valve for RVOT Reconstruction A monocusp may be created with autologous or bovine pericardium , homograft pulmonary valve cusp, or as reported in this technique section, the use of PTFE pericardial membrane (0.1 mm PTFE patch) The monocusp has been shown, particularly in the immediate postoperative period, to prevent pulmonary valve insufficiency The potential disadvantage in comparison to insertion of a pulmonary valve or valved conduit is that, at least in some patients, there appears to be a faster progression to recurrent pulmonary valve insufficiency, although late stenosis is rarely, if ever, seen using this technique. Turrentine MW, McCarthy RP, Vijay P, Fiore AC, Brown JW. Polytetrafluoroethylene monocusp valve technique for right ventricular outflow tract reconstruction. The Annals of thoracic surgery. 2002 Dec 1;74(6):2202-5.
- 113. • Presented in American Association of Thoracic Surgery Meeting , 2015 • Study between 1994-2014 • 171 patients • The PTFE-MOTP decreased 6-month mortality, ICU stay, and decreased the need for inotropic support, improving short-term outcomes • . Endocarditis, residual VSD, RVOT pseudoaneurysm, and supravalvular or subvalvular stenosis were the more common indications for PTFE-MOTP reoperation within the first 5 years after initial insertion • At 15 years, many PTFEM-OTP patients had moderate regurgitation but developed little RV dilation. • The PTFE-MOTP is a simple and inexpensive shortand mid- term option for initial RVOT reconstruction, particularly in children
- 114. Bicuspid PTFE pulmonary valve (florida technique) Quintessenza JA. Polytetrafluoroethylene bicuspid pulmonary valve implantation. Operative Techniques in Thoracic and Cardiovascular Surgery. 2008 Dec 1;13(4):244-9. • PTFE bicuspid PVR has been used in somewhat older children (8 years) and young adults, where a 24-mm orifice of the valve can be obtained. • An ideal implant recipient is the patient who has undergone previous repair of tetralogy of Fallot with a transannular patch, leading to severe PI and right ventricular dilation. The initial report of this technique includes the first 41 patients of our series, demonstrating improvement in pulmonary insufficiency, right ventricular end-diastolic dimensions, and symptoms over a mean follow-up period of 18 months. A
- 119. Hand sewn PTFE valve (Graham nunn technique, Austrailia)- description and results • JTCS, 2008 • reviewed all hand-sewn right ventricular outlet valves created by the author (Graham R. Nunn) • A total of 54 patients met the selection criteria Your text here • 22 patients received fresh autologous pericardial monocusps, 7 patients received polytetrafluoroethylene (0.1-mm) monocusps, and 25 patients received bileaflet polytetrafluoroethylene (0.1-mm) outlet valves. • Pericardial valves – all developed incompetence • Monocusp PTFE- early reliable competence but progression to PI • Bileaflet PTFE- have remained competent with RF of 5% to 30 % ( 5 yr follow up )
- 120. Fashioning the valve into outlet
- 122. Annular enlargement with valve repair (Sung, korea) 2003, THE SOCIETY OF THORACIC SURGEONS
- 123. Pulmonary cusp and annular extension technique(Japan) Yuji Hiramatsu, MD, PhD, 2014, THE SOCIETY OF THORACIC SURGEONS • The important concept of this technique is the preservation of the pulmonary valve coaptation mechanism as well as the cusp suspension mechanism • The multipurpose pericardial patch is designed to shape the sinus of Valsalva while it augments the cusp, annulus, and main pulmonary artery. • The second ePTFE patch has the specific role of reinforcing the extended portion of the annulus and therefore may prevent pathologic dilatation of RVOT
- 124. Recommendations for follow-up- institutional guidelines for TOF All patients with TOF require lifelong follow-up in view of the above-listed postoperative issues. Asymptomatic patients with no residual lesion but with free pulmonary regurgitation, not intervention, should be followed up 1–2 yearly. Clinical assessment, ECG, and echocardiogram are to be done at each visit. Holter monitoring is indicated in patients suspected of having arrhythmia. Cardiac catheterization should be performed if any residual lesion is suspected. It may also be required for a percutaneous intervention such as stenting of pulmonary artery branch for Cont-
- 125. cMRI is an important investigation for follow-up of these patients. In asymptomatic patients, baseline study should be performed 10 years after surgery with periodic follow-up, with frequency of repeat imaging determined by anatomic and physiological findings. Right ventricular volumes and function assessment by cMRI are an important indicator for pulmonary valve replacement. Those who have undergone a prosthetic pulmonary valve replacement require periodic monitoring of anticoagulation (INR levels). However, bioprosthetic valves are more commonly used for pulmonary valve replacement and these patients do not require long-term anticoagulation. IE prophylaxis is indicated in noncorrected patients, patients after surgical repair for 6 months, and patients with percutaneous or surgical pulmonary valve replacement. However, all patients with TOF are advised to maintain good oro-dental hygiene even after 6 months of surgical repair. Saxena A, Relan J, Agarwal R, Awasthy N, Azad S, Chakrabarty M, Dagar KS, Devagourou V, Dharan BS, Gupta SK, Iyer KS. Indian guidelines for indications and timing of intervention for common congenital heart diseases: Revised and updated consensus statement of the Working group on management of congenital heart diseases. Annals of Pediatric Cardiology. 2019 Sep;12(3):254.
- 126. Native pulmonary valve reconstruction , Marvoudis (2013) WJPCHS
- 129. PULMONARY VALVE REPLACEMENT FREE PR WELL TOLERATED FOR A DECADE OR TWO RESULTS IN SIGNIFICANT RV DILATATION AND DYSFUNCTION CLINICAL ASSESSMENT BEST INVESTIGATED BY MRI FOR ASSESSMENT OF VALVE REPLACEMENT MINIMIZE POST OP PR
- 130. RECOMMENDED CRITERIA BY GEVA T (2006) FOR PULMONARY VALVE REPLACEMENT 1. RV REGURGITATION FRACTION ≥ 25 % PLUS 2. TWO OR MORE OF THE FOLLOWING - RVed vol index ≥160ml/m sq. - RVes vol index ≥ 70ml/m sq. - Lves vol index ≥ 65ml/m sq. - RV EF ≤ 45% - RV outflow tract aneurysm - exercise intolerance, syncope, presence of heart failure, sustained VT and QRS > 120msec
- 131. Modifiers to above criteria :- Associated moderate to severe TR, residual ASD/VSD, severe AR PR with stenosis of main or branch Pas Older age at TOF repair
- 132. Recent cut offs by Lee C et al (2012) RV end systolic volume index ≥ 80ml/m sq. RV end diastolic volume index ≥ 163ml/m sq
- 133. Recommendations - AHA guidelines
- 134. INSTTITUTIONAL GUIDELINES Symptomatic patients with symptoms attributed to severe right ventricular volume overload with moderate or severe pulmonary regurgitation (Class I). Asymptomatic with any two or more of following (Class IIa): -Mild or moderate right ventricular or left ventricular dysfunction. -Severe right ventricular dilation: right ventricular end-diastolic volume >160 ml/m2, right ventricular end-systolic volume >80 ml/m2, or right ventricular end-diastolic volume ≥2 times left ventricular end diastolic volume. -Right ventricular systolic pressure ≥2/3 of systemic pressure due to right ventricular outflow tract obstruction.Progressive reduction in objective exercise tolerance. Sustained tachyarrhythmias (Class IIb) Residual lesions requiring surgical intervention (Class IIb).
- 135. Pulmonary valve replacement Surgical Transcutaneous Hybrid
- 136. Valve options Allograft – aortic and pulmonary homografts • xenograft • Bioprosthetic stented valve • Bioprosthetic stentless valve -bovine jugular vein (12-22mm, contegra) -porcine pulmonary valved conduit(10-24mm, shelhigh) - porcine aortic root (19-24mm, Medtronic freestyle ) • Mechanical valve • ePTFE valve (monocusp, bicuspid, tricuspid) • Transcatheter pulmonary valve (Melody, Sapien)
- 137. Valve options
- 138. Transcutaneous PVR There is a limitation of the size of prosthesis, which can be inserted, currently up to 22 mm with the Melody valve (Medtronic Inc., Minneapolis, MN, USA) and up to 29 mm diameter with the Sapien transcatheter heart valve (Edwards Life-sciences LLC, Irvine, CA, USA) the technique does not offer the opportunity of treating additional defects that are frequently associated with severe PR, such as pulmonary artery dilatation, and it cannot be used in the dilated native RVOT, which constitutes over 85% of patients with ToF requiring pulmonary valve replacement endocarditis
- 140. Contraindications : - Unsuitable peripheral venous anatomy Unfavourable RVOT for good stent anchorage Severe RVOTO that can not be balloon dilated Obstruction of central veins Active endocarditis/any other infection Pregnancy Known allergy to aspirin/heparin
- 141. Studies comparing TPVR vs SPVR : - Daily JA, Tang X, Angtuaco M, Bolin E, Lang SM, Collins II RT. Transcatheter versus surgical pulmonary valve replacement in repaired tetralogy of Fallot. The American journal of cardiology. 2018 Aug 1;122(3):498-504. SYSMATIC REVIEW AND META ANALYSIS Ribeiro JM, Teixeira R, Lopes J, Costa M, Pires A, Gonçalves L. Transcatheter versus surgical pulmonary valve replacement–A systemic review and meta-analysis. The Annals of Thoracic Surgery. 2020 Apr 5.
- 143. SPVR VS TPVR Restrospective study, who underwent either S-PVR or TC-PVR at any of the PHIS hospitals from January 1, 2010 to December 31, 2016. . Discharge mortality, adjusted billed charges, estimated cost, acute kidney failure, and surgical complication (any) rate were not significantly different between the 2 groups. Cardiac surgical complications were more common with TC-PVR, and respiratory, hemorrhage/hematoma, infection/fever, and other complications were more common with S-PVR. LOS and hospital resource utilization were lower with TC-PVR than S-PVR our study has shown that even when wage losses were included, TC-PVR remains more expensive when considered from a perspective of total 5-year cost.
- 144. Hybrid procedure full median sternotomy-plication of the pulmonary artery- a stab incision on the anterior surface of the proximal RVOT just proximal to the infundibulum/infundibular patch,avoiding calcified tissue. A valve 2 mm in diameter larger than the maximum size measured is gently compressed into the introducer and slid into the provided trocar. The injector is then slid into the RVOT and advanced to the main PA. The trocar delivery system is then withdrawn and the purse-string sutures controlled Sub xiphoid approach in children Melody valve placed transvenous + thoracotomy or midline incision
- 146. Late complications management TOF Routine follow up ( clinical, CXR, ECG, HOLTER, ECHO/MRI, CATH) Anticoagulation ( post PVR) IE prophylaxis Arrhythmia management Management of heart failure/ Ventricular dysfunction
- 147. Cont Risk factors for SCD include: a. LV systolic or diastolic dysfunction b. Nonsustained VT c. QRS duration ≥180 ms d. Extensive RV scarring e. Inducible sustained VT at electrophysiological study Ventricular Dysfunction - Shock - Symptomatioc - Asymptomatic
- 148. RESULTS TOF EARLY HOSPITAL MORTALITY SURGICAL MORTALITY 1960s 20 – 30% 1980s 10 -12 % 1990s-5% Present Day 2 – 5% (< 1 % In Some Series) SURGICAL MORTALITY (AIIMS) • 1965 – 1980 - 27.1% • 1981 – 1990-9.8% • 1991 – 2001- 3.7% • Present Day- Lesser
- 149. Survival Early and time related survival An institution that repairs early may have higher mortality and also saving more lives ! Murphy and colleagues in a 30 yr follow up of patients who left hospital alive, survival was 86% compared to 96% in general population Time related survival of most patients under proper circumstances is excellent, but the risk of death is always higher than general population
- 150. RISK FACTORS OF EARLY MORTALITY PATIENT /PRE-OPERATIVE FACTORS Age- Very early age of repair / Old age at repair RVOT/PA morphology Multiple VSDs Presence of other associated lesions Previous palliative procedures * Specific considerations in Adult TOF
- 151. Cont - Higher hematocrit at the time of surgery (earlier surgical era) Low LVed vol Earlier Era 1 • Large AP Collaterals • > 1 Surgical Palliative Shuntsii INTRA OPERATIVE High intraoperative pRV/LV* Use of Trans annular patch
- 152. Causes of early mortality • Low cardiac output Residual surgical lesion RV Dysfunction • Neurologic insult • Arrhythmias • Hepatorenal failure • Sepsis • Pulmonary hemorrhage
- 153. Palliative shunts and mortality A single shunt surgery was not found to be risk factor More than one shunt surgeries were associated with increased mortality Development of severe PAH Pa distortion Increased late mortality following Waterston and Pott shunt Nollert G, Fischlein T, Bouterwek S, Böhmer C, Klinner W, Reichart B. Long-Term Survival in Patients With Repair of Tetralogy of Fallot: 36-Year Follow-Up of 490 Survivors of the First Year After Surgical Repair. J Am Coll Cardiol. 1997;30(5):1374-1383. doi:10.1016/S0735-1097(97)00318-5.
- 154. pRV/LV ratio effect on survival HIGH p RV/LV SIGNIFIES RESIDUAL STENOSIS. Ratio measured in the ICU(24 hr after the operation) is more powerful and precise predictor (Kirklin) HIGH p RV/LV IS A RISK FACTOR FOR EARLY AND LATE MORTALITY The effect is diluted after 20 years post operatively Significance of trans annular patch is low if p RV/LV is low SURVIVAL 10 YRS 15 YRS 20 YRS 25 YRS 30 YRS <0.5 94% 93% 92% 88% 87% >0.5 88% 88% 88% 86% 85%
- 155. Risk factors- late mortality PATIENT FACTORS • Adult or very young Age • Polycythemia • Downs Syndrome • Multiple V.S.D • Large A.P collaterals SURGICAL FACTORS •Surgical era •Prior Shunt Operation •Trans Annular Patch •Surgical Approach •Post repair p RV / LV •Heart Block
- 156. Causes of late mortality • Arrhythmia (Most common cause) • Cardiac Failure • Residual/ Recurrent VSD • Reoperations • RVOT Complications • Complete Heart Block • Myocardial infarction • Rare causes: • Renal failure • Brain Abscess • Stroke Nollert G, Fischlein T, Bouterwek S, Böhmer C, Klinner W, Reichart B. Long-Term Survival in Patients With Repair of Tetralogy of Fallot: 36-Year Follow-Up of 490 Survivors of the First Year After Surgical Repair. J Am Coll Cardiol. 1997;30(5):1374-1383 Murphy JG, Gersh BJ, Mair DD, Fuster V, McGoon MD, Ilstrup DM, McGoon DC, Kirklin JW, Danielson GK. Long-term outcome in patients undergoing surgical repair of tetralogy of FallotN Engl J Med. 1993 Aug 26;329(9):593-9
- 157. POST –OPERATIVE FUNCTIONAL STATUS
- 158. Indications for re-operations • Residual VSD • RVOTO • Pulmonary regurgitation • Aortic Regurgitation • R V / RVOT Aneurysms • Arrhythmias • Tricuspid regurgitation
- 159. Post PVR results Cheung EW, Wong WH, Cheung YF. Meta-analysis of pulmonary valve replacement after operative repair of tetralogy of fallot. The American journal of cardiology. 2010 Aug 15;106(4):552-7.
- 160. TOF repair in Infancy The advantages are : i) Less myocardial fibrosis and cyanosis induced myocardial dysfunction. ii) Need of infundibular resection is less. iii) Obviates the need for palliative procedures iv) Reduces the risk of sudden death v) Less incidence of ventricular ectopic activity The problems faced during repair in infancy are i) Small size ii) CPB related problems iii) More frequent use of a transannular patch and its problems in follow up. iv) High PVR
- 161. TOF REPAIR IN ADULTS Neurological problems: There is increased incidence of brain abscess and cereberovascular accidents. Coagulation disorders which lead to renal/hepatic/pulmonary and bleeding complications. Myocardial fibrosis/dysfunction leading to low output syndrome. Increased incidence of major aortopulmonarycollaterals. Increased incidence of subacute bacterial endocarditis/pulmonary valvular thickening, calcification and dystroply.
- 162. Various intraoperative problems faced in this subgroup are : 1. Excessive return to the left atrium 2. Severe infundibular stenosis requiring excessive resection. 3. Difficult exposure because of large size and right ventricular hypertrophy. 4. Increased incidence of transannular patch. 5. Difficulty in myocardial preservation because of excessive collaterals. 6. Bleeding 7. Low cardiac output: increased requirement of inotropic support and need for higher filling pressures.
- 163. Pregnancy places a physiologic load on the cardiovascular system Can cause: Progression of RV dysfunction Atrial and ventricular dysrhythmias Thromboembolic phenomena Maternal or fetal death/ IUGR Offspring more likely to have congenital heart disease (approximately 3.1%) Vaginal delivery is preferred for most TOF patients May benefit from surgical repair before pregnancy. Women with pulm hypertension or significant LV dysfunction should be counseled about their cardiovascular risk and advised against pregnancy. Pregnancy outcomes in patients with TOF repair Veldtman G, Connolly H, Grogan M, Ammash N, Warnes C. Outcomes of pregnancy in women with tetralogy of fallot. J Am Coll Cardiol. 2004;44(1):174-180.
- 164. INTELLECTUAL/SOCIAL STATUS Early correction of cyanosis promotes development of cognitive and intellectual development Of the first 106 patients operated by Lillehei group 34 Completed college 10 Graduates 5 Masters 2 Doctors 2 PHD 1 Lawer Ist Patient became a Professional Musician 88 Pregnancies - 93% live births with slight increased rate of LSCS ( 42% for untreated and 72% after shunts) 7.3 % congenital cardiac lesions in progeny
- 165. AIIMS experience CS Sadasivan Oration by Prof Balram Airan • 190 Neonatal Corrections (1985 - 2001) • Surgical approach Transventricular 100 Trans RA + PA 69 Trans atrial 21 • 5.3% Early Deaths Due to Low Cardiac Output Infection Renal failure • Morbidity included Complete Heart Block (4) Insignificant Residual VSD (4) RVOT Gradient (11)
- 166. IDEAL TOF REPAIR Suitable for all age and weight Good relief of RVOT and prevent RV hypertrophy Complete atrial and ventricular separation Avoid ventriculotomy and circulatory arrest Preserve PV and TV function Preserve contractility Minimum early mortality and morbidity Good functional status and quality of life Freedom from reoperation and late morbidity
- 167. VARIANTS OF TOF TOF WITH PULMONARY ATRESIA - 15-20% of cases - PDA (vertical ductus) AND MAPCAs - NON CONFLUENCE, HYPOPLASIA AND ABNORMAL DISTRIBUTION TOF WITH ABSENT PULMONARY VALVE - 2% of cases - Annulus stenotic with aneurysmal Pas - Hypoplasia of compressed airways - Surgical mortality high with pulmonary complications - Primary repair is treatment of choice
- 168. TOF WITH PULMONARY ATRESIA Often severely cyanotic PGE1 infusion to maintain ductal patency Emergency shunt procedure Single stage repair Multiple stage repair
- 169. Single stage repair Prerequisites Embolization of APCs VSD closure + RV-unifocalized PA continuity Nakata index > 200 favoured
- 170. Multiple stage repair When single stage prerequisites not met Stage 1 Shunt / RV-PA conduit Stage 2 unifocalization Stage 3 VSD closure , conduit replacement Cath study at 3-6 months Cath study at 3-6 months