CPT® Code 33745

1. Indications

Transcatheter intracardiac shunt (TIS) creation by stent placement is indicated for the following conditions:

• Hypoplastic Left Heart Syndrome - This condition may present with an obstructed Fontan fenestration, necessitating intervention to improve blood flow.
• Right Ventricular Outflow Tract Obstruction - Patients with repaired congenital heart disease may experience this obstruction, requiring stent placement to restore effective flow.
• Narrowed or Stenotic Baffles - Issues arising from previous surgical procedures, such as the Mustard, Senning, or Warden techniques, can lead to complications that necessitate this procedure.

2. Procedure

The procedure for transcatheter intracardiac shunt (TIS) creation by stent placement involves several critical steps:

• Puncture of Venous Sites - Two venous access points, typically the femoral and subclavian veins, along with a femoral artery, are punctured to facilitate catheter placement.
• Sheath Placement - Sheaths are introduced through the punctured sites to allow for the insertion of diagnostic catheters.
• Diagnostic Catheterization - Diagnostic catheters are maneuvered through the sheaths to the target area, where baseline pressures and blood samples are obtained from each right and left heart structure.
• Angiography - An angiogram may be performed to visualize the heart chambers and vessels, which may require changing catheters for optimal access.
• Wire Placement - A wire is placed across the stenotic fenestration into the right atrium to facilitate further intervention.
• Sheath Exchange - The diagnostic sheath is exchanged for a larger therapeutic sheath, which is advanced over the wire into the right atrium.
• Balloon Angioplasty - If necessary, a small balloon may be inflated to dilate the stenotic fenestration, allowing the sheath to cross the obstruction.
• Stent Preparation - An appropriate stent is prepared and mounted onto a balloon, which is then threaded over the wire to the sheath tip.
• Stent Positioning - The system is carefully withdrawn to center the stent over the fenestration, with imaging guidance used to confirm proper placement.
• Stent Deployment - The sheath is pulled back to flare open the stent within the atrium, ensuring that the stent is properly seated and expanded.
• Final Angiography - After stent placement, another angiogram is performed to assess the success of the procedure and to check pressures in the atrium before sheath removal.
• Completion of Procedure - An angiogram in the Fontan conduit may be conducted, and left and right heart catheterization may be repeated as necessary before concluding the procedure.

3. Post-Procedure

Post-procedure care for patients undergoing transcatheter intracardiac shunt (TIS) creation includes monitoring for any complications related to the procedure, such as bleeding or infection at the access sites. Patients may require follow-up imaging to assess the position and function of the stent. Additionally, ongoing evaluation of cardiac function and hemodynamics is essential to ensure that the intended improvements in blood flow are achieved. The healthcare team will provide specific instructions regarding activity restrictions and any necessary medications to support recovery.