MAPCA Coiling — Cost, Top Hospitals & Success Rates | MyMedicPlus

Major Aortopulmonary Collateral Arteries (MAPCAs) are abnormal blood vessels that arise from the descending aorta, subclavian arteries, or other systemic vessels to supply blood to one or both lungs when the native pulmonary arterial circulation is absent or severely underdeveloped. They represent the body's attempt to compensate for absent pulmonary blood flow but become haemodynamically problematic when they are too large, tortuous, or numerous.

MAPCA coiling is an interventional catheter-based procedure in which these aberrant vessels are deliberately occluded using metallic coils or vascular plugs delivered via a catheter under fluoroscopic guidance. The procedure is typically performed in the cardiac catheterisation laboratory under general anaesthesia in paediatric patients.

The fundamental objective of MAPCA coiling is to rationalise pulmonary blood supply before or after definitive surgical repair (unifocalisation and complete repair) by:

• Eliminating redundant or competitive blood supply to pulmonary segments already served by true pulmonary arteries or surgically constructed neopulmonary arteries
• Reducing excessive pulmonary blood flow that can cause volume overload of the heart and pulmonary hypertensive changes in the lung vasculature
• Simplifying the surgical field for the cardiac surgeon at the time of unifocalisation
• Preventing post-operative pulmonary oedema or haemorrhage from runaway MAPCA flow after repair

MAPCAs occur in approximately 30–40% of patients with Tetralogy of Fallot with Pulmonary Atresia (TOF-PA) and are also seen in other complex cyanotic congenital heart defects including truncus arteriosus and pulmonary atresia with intact ventricular septum.

MAPCA coiling addresses collateral vessel haemodynamics in several complex congenital cardiac conditions:

• Tetralogy of Fallot with Pulmonary Atresia (TOF-PA) and MAPCAs: The paradigmatic indication. In TOF-PA, the right ventricular outflow tract does not connect to the pulmonary vasculature. Pulmonary blood flow is entirely dependent on a patent ductus arteriosus (which closes after birth) and MAPCAs. The management strategy — whether to coil, unifocalise, or ligate specific MAPCAs — is planned individually based on CT angiography and catheter haemodynamic data.
• Truncus Arteriosus with Pulmonary Collaterals: After repair of the truncus and placement of a right ventricle-to-pulmonary artery conduit, residual MAPCAs may cause pulmonary overcirculation.
• Pulmonary Atresia with Intact Ventricular Septum (PA-IVS): Some patients develop significant systemic-to-pulmonary collaterals that require occlusion after right ventricular outflow reconstruction.
• Single Ventricle Physiology (Pre-Fontan): In patients undergoing staged Fontan palliation, MAPCAs can cause competitive pulmonary blood flow that compromises Glenn or Fontan haemodynamics. Coiling is performed to optimise pulmonary vascular resistance before Fontan completion.
• Post-surgical Residual or Recanalised Collaterals: Surgical ligation of MAPCAs is sometimes incomplete, or collaterals may recanalise after surgery, requiring catheter-based occlusion as a secondary intervention.

The decision to coil a MAPCA is complex and requires a multidisciplinary team approach including paediatric cardiologists, congenital cardiac surgeons, and interventional cardiologists. Key selection criteria include:

Candidates for MAPCA Coiling

• MAPCAs supplying pulmonary segments already served by native or surgically created true pulmonary arteries (dual supply segments) — coiling eliminates competitive flow
• MAPCAs causing excessive pulmonary overcirculation and signs of volume overload (elevated mixed venous saturation, cardiomegaly, pulmonary oedema)
• Large MAPCAs that would create an unacceptably high intraoperative surgical field when performing unifocalisation
• MAPCAs in patients awaiting Fontan completion whose elevated pulmonary blood flow is compromising Glenn shunt haemodynamics
• Patients with adequate systemic oxygen saturation (SpO₂ >75%) indicating sufficient alternative pulmonary blood supply

Contraindications

• MAPCAs that are the sole source of pulmonary blood supply to a viable lung segment — coiling would cause infarction of that segment
• Critically cyanotic patients (SpO₂ <70%) where any reduction in pulmonary blood flow is haemodynamically unsafe
• Severe coagulopathy or active systemic infection
• Anatomic inaccessibility of the target vessel via catheter approach

Pre-procedure evaluation typically includes cardiac CT angiography with 3D reconstruction (the gold standard for MAPCA mapping), echocardiography, and diagnostic cardiac catheterisation with selective angiography of the aorta and each suspected MAPCA to define its origin, course, and pulmonary territory supplied.

Several catheter-based occlusion strategies are available, with selection dependent on vessel size, anatomy, and institutional preference:

1. Metallic Coil Embolisation

Platinum or stainless-steel Gianturco coils are the most widely used devices. Coils are delivered through a catheter positioned within the target MAPCA and deploy to fill and occlude the vessel lumen. Multiple coils may be required for larger vessels. The coils induce thrombosis and fibrous occlusion over 2–4 weeks. Sizes range from 3 to 15 mm in diameter, suitable for MAPCAs typically 2–8 mm in diameter. Detachable coil systems (e.g., Interlock, Boston Scientific) allow repositioning before final deployment if the initial position is suboptimal.

2. Vascular Plug Occlusion (Amplatzer Vascular Plug)

For larger MAPCAs (typically >6 mm in diameter), nitinol mesh vascular plugs (AVP II or AVP IV) provide more reliable occlusion with less risk of device migration compared to coils. The plug is deployed at the target segment, checked for stability via angiography, then detached. This device allows precise placement and is retrievable before detachment.

3. Combined Surgical and Catheter-based Approach (Hybrid)

In many major congenital cardiac centres, MAPCA coiling is part of a staged hybrid strategy. Accessible MAPCAs are coiled in the catheterisation lab pre-operatively; surgically accessible MAPCAs are ligated at the time of unifocalisation; and residual collaterals are addressed post-operatively by catheter. This multi-stage approach reduces the complexity of each individual intervention.

4. Surgical Ligation or Unifocalisation

When MAPCAs are large, arise near major structures, or supply significant pulmonary territory, surgical unifocalisation (incorporating the MAPCA into the native pulmonary arterial tree) is preferred over coiling. This is the approach championed by Hanley and colleagues at Stanford for TOF-PA with MAPCAs.

When performed by experienced interventional cardiologists in appropriately selected patients, MAPCA coiling offers significant haemodynamic and clinical benefits:

• Pulmonary Haemodynamic Optimisation: Reduction of Qp:Qs ratio (pulmonary to systemic flow ratio) to the desired range, reducing volume load on the ventricle and lowering pulmonary artery pressures in over-circulated segments.
• Simplified Surgical Field: Pre-operative coiling of accessible MAPCAs reduces intraoperative blood loss and operative time during unifocalisation by eliminating competitive vessels that the surgeon would otherwise need to ligate.
• Improved Fontan Haemodynamics: In single-ventricle patients, pre-Fontan MAPCA coiling has been associated with improved post-operative haemodynamics, lower transpulmonary gradients, and shorter intensive care unit stays.
• Staged Palliation Safety: Allows haemodynamic optimisation between staged surgical procedures without requiring the risk of an additional open-heart operation.
• Technical Success Rate: Published series from major paediatric cardiac centres report technical coil/plug deployment success rates of >95%, with complete occlusion confirmed angiographically in 85–90% of target vessels.
• Low Procedural Mortality: In experienced centres, catheterisation-associated mortality for MAPCA coiling is <0.5% when patients are carefully selected to exclude those with sole-supply MAPCAs.

MAPCA coiling carries procedural risks that must be discussed with the family and the multidisciplinary cardiac team:

Acute Procedural Risks

• Device Migration or Embolisation: Coils or plugs can migrate from the target vessel into the true pulmonary arteries or systemic circulation. Migration occurs in approximately 1–3% of cases and may require catheter retrieval using snare devices or, rarely, surgical extraction.
• Inadvertent Occlusion of Adjacent Vessels: Particularly a risk when a MAPCA arises close to a spinal artery (artery of Adamkiewicz), which can cause spinal ischaemia and paraplegia — a rare but catastrophic complication. Careful angiographic mapping is essential before coiling vessels arising from the descending aorta.
• Pulmonary Infarction: Coiling a MAPCA that was the sole blood supply to a pulmonary segment causes infarction of that segment, manifesting as haemoptysis, fever, and reduced lung volume. Preoperative CT and angiographic assessment must exclude sole-supply collaterals.
• Paradoxical Embolism: In patients with intracardiac communications (e.g., VSD), a coil that migrates into the venous circulation can cross to the systemic arterial circulation.

Access-related Risks

• Vascular access haematoma, arterial dissection, or thrombosis at the femoral artery or vein puncture site
• Contrast nephropathy — particularly relevant in cyanotic patients with polycythaemia and elevated haematocrit
• Radiation exposure — procedures can be prolonged with multiple selective angiographic runs; dose optimisation is essential in children

Post-procedural Risks

• Recanalization of coiled vessels in approximately 5–15% of cases, requiring repeat coiling
• Acute haemodynamic deterioration if oxygen saturation falls unexpectedly after coiling, indicating inadvertent sole-supply occlusion

Post-procedural monitoring and follow-up are an integral component of care in this complex patient population:

Immediate Post-procedure (0–24 hours)

• Continuous pulse oximetry monitoring in the cardiac intensive care unit (CICU) or step-down unit is mandatory. A fall in SpO₂ >5% below pre-procedure baseline warrants urgent cardiology review to exclude inadvertent sole-supply MAPCA occlusion.
• Access site assessment every 2–4 hours for haematoma, loss of distal pulses, or limb coolness.
• Hydration protocols to prevent contrast nephropathy, particularly in polycythaemic patients.
• Chest radiograph to confirm coil position and exclude pneumothorax or significant effusion.

Short-term Follow-up (1–8 Weeks)

• Echocardiography and clinical review at 2–4 weeks to assess ventricular function and pulmonary haemodynamics.
• Repeat cardiac catheterisation or CT angiography may be performed at 4–8 weeks to confirm MAPCA occlusion and assess readiness for the next surgical stage.
• Haematological review in polycythaemic patients — iron supplementation to prevent relative iron deficiency anaemia.

Long-term Surveillance

• All patients with TOF-PA and MAPCAs require lifelong cardiology follow-up with annual echocardiography and periodic cardiac MRI to assess right ventricular function, conduit integrity, and pulmonary artery growth.
• Repeat catheterisation for re-intervention on residual or recanalised MAPCAs as clinically indicated, typically every 2–3 years in the pre-surgical staged palliation period.
• Comprehensive neurodevelopmental assessment given the high rate of neurodevelopmental comorbidities in this patient population.

The cost of MAPCA coiling varies considerably depending on patient complexity, number of vessels treated, and geographic location:

• Number of MAPCAs Targeted: Each MAPCA requiring separate catheter positioning, selective angiography, and device deployment adds to procedure time, contrast use, and device costs. Some patients have 3–8 MAPCAs requiring staged coiling over multiple catheterisation sessions.
• Device Costs: Individual coils cost $100–$500 (USD) each; Amplatzer vascular plugs range from $2,000–$5,000 each. Multiple devices per vessel and multiple sessions multiply total device costs significantly.
• Cardiac Catheterisation Laboratory Fees: Specialised paediatric cardiac catheterisation labs with biplane fluoroscopy, intracardiac echocardiography capability, and cardiac ICU support command premium facility fees.
• Paediatric Specialist Fees: Congenital interventional cardiologists with MAPCA coiling expertise are highly specialised; their fees reflect the complexity and rarity of the procedure.
• Anaesthesia: General anaesthesia with paediatric cardiac anaesthesiologists is required for most patients, adding to total costs.
• Hospital Setting: Procedures at quaternary-level paediatric cardiac centres in countries such as India (Chennai, Mumbai), Thailand (Bangkok), and Turkey (Istanbul) offer high-quality care at 50–70% lower cost than equivalent US or UK centres, without compromising safety for carefully selected patients.
• Insurance Coverage: In most countries with insurance systems, MAPCA coiling is covered for patients with established diagnoses of TOF-PA or equivalent complex CHD. Pre-authorisation is typically required.

Management of MAPCAs must be considered within the overall surgical strategy for the underlying congenital heart defect. Alternatives and complementary approaches include:

• Surgical Ligation: Direct surgical ligation at the time of open-heart repair is the traditional approach. It avoids the need for a separate catheterisation procedure but increases operative complexity and blood loss at the time of unifocalisation.
• Unifocalisation (Surgical): Rather than occluding the MAPCA, the Stanford approach incorporates large MAPCAs into a surgically constructed neopulmonary arterial tree. This approach preserves pulmonary segments and maximises native pulmonary tissue for eventual complete repair with VSD closure.
• Expectant Management (Observation): Small MAPCAs (<2 mm) with minimal haemodynamic contribution may be observed rather than coiled, as they frequently thrombose spontaneously after surgical repair.
• Stent Implantation: In contrast to coiling, stenting is used to open (rather than occlude) stenotic true pulmonary artery segments in TOF-PA to promote pulmonary artery growth before complete repair — a related but distinct interventional strategy.
• Systemic-to-Pulmonary Artery Shunt (Blalock-Taussig-Thomas Shunt): In patients whose native pulmonary blood supply is entirely MAPCA-dependent and who are too small or too sick for complete repair, a surgical shunt provides reliable, controllable pulmonary blood supply. MAPCAs can then be addressed at a subsequent stage.