Best Hospitals for Aortopulmonary Window Repair in Mumbai, India

Aortopulmonary Window (APW), also termed aortopulmonary septal defect, is a congenital cardiac anomaly characterized by a direct communication between the left lateral wall of the ascending aorta and the right wall of the main or proximal branch pulmonary artery, in the presence of two separate, morphologically normal semilunar valves. This anatomical distinction separates APW from truncus arteriosus. The defect is classified by the Mori classification (Type I: proximal/simple; Type II: distal involving the right pulmonary artery origin; Type III: total or mixed) and by the Richardson classification, which guides operative planning. The pathophysiology is dominated by a large, obligatory left-to-right shunt: oxygenated aortic blood recirculates through the pulmonary vasculature, causing pulmonary overcirculation, progressive pulmonary arterial hypertension, right ventricular pressure overload, and, in unrepaired cases, Eisenmenger physiology by the first or second year of life.

• **Definitive surgical candidates:** Neonates, infants, and young children diagnosed with APW (Mori Type I, II, or III / Richardson Type 1, 2, or 3) with a hemodynamically significant left-to-right shunt (Qp:Qs > 1.5:1) and pulmonary vascular resistance index (PVRi) < 8 Wood Units/m².
• **Older children with borderline PVR:** Patients aged 1–5 years with PVRi 6–8 WU/m² may undergo cardiac catheterization with vasoreactivity testing (100% oxygen and/or iNO); operability is confirmed if PVR/SVR ratio falls below 0.4 on testing.
• **Associated anomalies requiring simultaneous repair:** Interrupted aortic arch (IAA), ventricular septal defect (VSD), patent ductus arteriosus (PDA), and anomalous right coronary artery from the pulmonary artery — all must be comprehensively mapped pre-operatively.
• **Required diagnostic workup:**

- Transthoracic echocardiography (TTE) and intraoperative transesophageal echocardiography (TEE): defect size, location, valve morphology, ventricular function

- Cardiac CT angiography (ECG-gated, low-dose): precise 3D anatomy, coronary origins, arch anatomy

**1. Open Surgical Repair via Median Sternotomy (Gold Standard)**

The definitive treatment for all APW types is surgical closure under cardiopulmonary bypass (CPB) with bicaval or aorto-caval cannulation, moderate hypothermia (28–32°C), and antegrade cold blood cardioplegia. The three principal intraoperative approaches are:

• **Transaortic Patch Technique (Preferred for Type I and II):** The ascending aorta is opened longitudinally after cross-clamping. The defect is visualized from within the aorta and closed using a pericardial or polytetrafluoroethylene (PTFE/Gore-Tex) patch sutured circumferentially. The patch is deliberately fashioned to avoid distortion of the right coronary ostium or the pulmonary valve. This approach provides the best visualization and is the most reproducible across centers.
• **Direct Division and Suture Technique (Small/Proximal Defects, Type I):** Suitable for small (<5 mm), proximal APW defects without associated anomalies. The window is divided on CPB and each orifice is closed primarily or with small pericardial patches on the aortic and pulmonary sides separately. Risk of inadequate hemostasis is higher than with the transaortic approach.
• **Transpulmonary Approach with Patch Augmentation (Type II/III, Involving RPA Origin):** When the defect extends to involve the origin of the right pulmonary artery, the pulmonary artery is opened and the patch is placed from the pulmonary side, with reconstruction of the right pulmonary artery confluence. This may require augmentation with a pericardial hood to prevent right pulmonary artery stenosis.
• **Combined Simultaneous Repair:** When APW coexists with IAA, aortic arch reconstruction is performed during the same bypass run using deep hypothermic circulatory arrest (DHCA) or selective cerebral perfusion, followed by APW patch closure — a technically demanding procedure requiring the highest level of neonatal cardiac surgical expertise.

**2. Intraoperative Adjuncts and Technology**

**Phase 1 — Pre-Operative Evaluation and Planning (Days 1–5 after arrival)** Upon arrival, the patient is admitted to the congenital cardiology unit. The comprehensive diagnostic workup is completed or reviewed: TTE/TEE, cardiac CTA, hemodynamic catheterization data, and laboratory studies. A multidisciplinary team conference involving the congenital cardiac surgeon, pediatric cardiologist, cardiac anesthesiologist, neonatologist/intensivist, and perfusionist reviews the case. Pre-operative optimization includes diuresis (furosemide, spironolactone) for pulmonary congestion, nutritional support (high-calorie feeds or nasogastric tube feeding in infants with failure to thrive), and antibiotic prophylaxis.

**Phase 2 — The Surgical Procedure (Day 5–7)** The operation is performed under general endotracheal anesthesia. Duration is typically 3–5 hours for isolated APW; 5–8 hours for complex combined repairs (APW + IAA). Key operative steps: median sternotomy → pericardial patch harvest → CPB cannulation → aortic cross-clamping → cardioplegia delivery → aortotomy → defect identification and patch closure under direct vision → aortotomy closure → CPB weaning with iNO support → decannulation → sternal closure (primary or delayed if ventricular edema warrants open sternum management).

**Phase 3 — Pediatric Cardiac ICU (PCICU) (Days 1–5 post-surgery)** The patient is managed intubated and sedated for 24–72 hours. Priorities include: controlled mechanical ventilation targeting mild hypercapnia to reduce pulmonary vascular resistance, continuous hemodynamic monitoring (arterial line, central venous pressure, near-continuous NIRS), inhaled nitric oxide titration and weaning, vasoactive support (milrinone, dopamine) as required, strict fluid balance, and daily echocardiographic assessment. Chest drain outputs, coagulation, and renal function are monitored closely. Milestones for PCICU discharge: extubation, iNO weaned off, stable hemodynamics on oral medications, tolerating enteral feeds.