Fontan operation: How I do it? Piya Samankatiwat Cardiothoracic Unit Ramathibodi hospital

What is the ‘single ventricle’? Prof. Richard van Praagh ‘One ventricular chamber receives blood from both tricuspid and mitral valve or a common atrioventricular valve’ Therefore, this excludes tricuspid atresia and mitral atresia.

So !!! you are in doubt what the univentricular physiology is. Prof. Robert H Anderson emphasised that ‘the entire atrioventricular junction is connected to only one chamber in the ventricular mass’ DILV Absent of one atrioventricular connection Common AV valve with one completely well-developed ventricule Only one fully developed ventricle Heterotaxy syndrome Rare miscellaneous forms

Univentricular heart Congenital heart surgery nomenclature and database Common inlet atrioventricular connection DILV DIRV Absence of one atrioventricular connection Tricuspid atresia Mitral atresia Common atrioventricular valve with one well- developed ventricle (unbalanced AVSD) Heterotaxia syndrome with only one fully developed ventricle Other rare forms of univentricular heart

R Kaulitz, M Hofbeck. Arch Dis Child 2005;90:757–762.

Evolution of surgery for single functioning ventricle 1940s Blalock-Taussig shunt 1952 PA banding by Muller WH and Dammann JF 1954 Shumacker and 1st cavopulmonary connection 1956 separation of single ventricle at Mayo Clinics 1971 Fontan’s and Kreutzer’s

Fontan procedure Background 1971 Fontan and Baudet first introduced a new procedure for repair of tricuspid atresia in clinical practice 1970s to 1980s became widely accepted as the palliative procedure of choice in univentricular heart physiology Physiological, not anatomical correction

First report in Thorax 1971 by F Fontan and E Baudet

Ten commandments (Fontan and Baudet) Age above 4 years No distortion of pulmonary arteries from prior shunt surgery Normal systemic venous drainage Normal ventricular function Adequate pulmonary artery size No atrio-ventricular valve regugitation Low pulmonary artery pressure (below 15 mmHg) Low PVR Normal sinus rhythm Adequate size of right atrium

Candidate for Fontan Body size Systemic ventricular function End diastolic pressure < 10 mmHg Mean PAP < 15 mmHg PVR < 2.5 Woods unit (2) Unrepairable pulmonary artery distortion ??? Abnormal IVC course: proceed to Fontan operation???

Principle of surgery for UVH Protect the lung: prevent pulmonary HT with PA banding Correct cyanosis: BT shunt Atrial septostomy/septectomy Relieve ventricular outflow tract obstruction Correct obstruction of pulmonary venous connection Correct valvular regurgitation

Operations: pre-Fontan palliation Pulmoanry artery banding Modified BT shunt Atrioventricular valve repair Correction of TAPVC (if present) DKS or Norwood principle Glenn’s shunt: superior cavopulmonary connection

Palliative procedures Pulmonary artery banding (PAB) Source: www.ucch.org

Blalock-Taussig shunt

DKS and Stage-I Norwood procedure

Glenn procedure SVC to pulmonary artery Patient selection: good candidate Pulmonary arterial pressure (PAP) mean < 20 mmHg Size of branch pulmonary arteries Preparation Bypass circuit: aortic/ SVC –RA venous cannulation

Special considerations for Glenn Additional sources of pulmonary blood flow Bilateral BDG Kawashima operation Hemi-Fontan procedure

Cavopulmonary shunt (Glenn) Source: www.ucch.org

Glenn shunt Surgical technique: How I do it? With/without CPB CPB: aortic cannulation and SVC-RA venous cannulation Essential steps: Extensive mobilisation of the SVC Cannulate the SVC at the SVC-innominate junction Keep azygos vein intact until starting the SVC-RPA anatomosis Limited PA dissection – no need for extensive dissection

Palliative definitive surgery: Fontan procedure Total cavopulmonary connection Fontan: IVC to PA Extracardiac conduit (ECC) Lateral tunnel (intracardiac baffle, LT)

Types of TCPC R Kaulitz, M Hofbeck. Arch Dis Child 2005;90:757–762.

Fontan operation

Extracardiac conduit

Completion of TCPC Surgical technique: How I do it? On CPB or Off-pump Dissection of IVC and PA Tailoring the PTFE conduit (at least size 16 mm should be selected for adequate IVC flow) Anastomosis: the IVC anastomosis is done first. Side-to-side fenestration

Fontan procedure I

Fontan procedure II

Fenestration and completion

Anomalous systemic venous return

Challenges Anatomical and technical Branch pulmonary artery stenosis and disconnected pulmonary artery Dextrocardia and Mesocardia Abnormal anatomy or position of the IVC Fenestration or non-fenestration Physiological Pulmonary hypertension

Advantage of fenestration Debate on routine fenestration Beneficial in high-risk Fontan Standard-risk group  controversial Randomised-controlled trial 49 cases underwent Fontan (< 2 risk factors) 25 fenestrated, 24 non-fenestrated 6 LT, 43 ECC Fenestrated group: less hospital stay, shorter duration of pleural drainage and less additional procedures Lemler MS, Scott WA, Leonard SR, et al. Circulation 2002; 105; 207-212

Factors associated with poor outcome Systemic ventricular dysfunction (EDP > 12) Increased pulmonary arterial pressure (mean > 15) Increased pulmonary vascular resistance (>2) Atrioventricular valve regurgitation Distorted pulmonary artery Anomalous pulmonary venous connection

Postoperative care Cardiac output depends primarily on pulmonary vascular resistance (PVR) and systemic ventricular function Positioning Extubation as early as possible Inotropes Vasodilators Reduction of pulmonary arterial pressure Anticoagulation: warfarin (how long???) Only aspirin: enough??? Ann Thorac Surg. 2002 Jan;73(1):64-8. (St Christopher Hospital, Philadelphia)

Sequelae of Fontan procedure Low cardiac output Pleural effusion Arrhythmia Protein losing enteropathy (PLE)  immunity loss Hepatic dysfunction Pulmonary arteriovenous malformation (AVM) in Kawashima Progressive cyanosis Chronic exercise intolerance Plastic bronchitis

Ramathibodi’s experience on surgical treatment of UVH Between 2007-2010: 64 operations in 52 patients Defects N Double inlet ventricle: DILV DIRV 6 1 Absence of one AV connection TA MA 14 3 Unbalanced AVSD 5 Heterotaxia syndrome Asplenia 11 Miscellaneous PA/IVS Complex DORV Other rare conditions (e.g. hypoplastic LV & AA , hypoplastic RV & TGA, dextrocardia/PS/common ventricle) 4

Ramathibodi’s experience on surgical treatment of UVH Operations N Results Glenn procedure 32 All alive Inferior cavo-pulmonary connection 3 Completion of TCPC 19 (S= 2/19) Dead 2 Kawashima operation 2 Alive Other palliative procedures Systemic to pulmonary shunt CoA repair +/- PAB 6 Late dead 1 PA plasty or reconnection 8

Case discussion: case I A male premature baby, birth weight 2.1 kg Respiratory distress with heart murmur No dysmorphic feature Normal S1, S2 with SEM gr 2/6 at LPSB

Investigation Echocardiography Single functioning morphologic RV, DIRV, DORV, rudimentary LV, large bulboventricular foramen Mild MS, No AS, No PS hypoplastic aortic arch 3 mm, severe CoA 2.5 mm, PDA 3.3 mm CTA heart

Operation and findings Severe coarctation of the aorta and hypoplastic aortic arch Hypoplastic LV Deep hypothermia + circulatory arrest Resection and end-to-end anastomosis Pulmonary artery banding

Case II 1-y-2-mo-old boy Cyanotic since birth Systolic ejection murmur gr 4/6 at LPSB

Investigation Echocardiography truncus arteriosus type I with moderate truncal valve regurgitation Cardiac catheterisation truncus arteriosus type I with PHT PVR 6 Woods unit

Findings and procedure Truncus type I, right sided aortic arch RPA & LPA 10 mm Tricuspid truncal valve with regurgitation due to redundancy of posterior truncal cusp Rastelli operation (using 13 mm pulmonary homograft)