I cannot provide actual ICE images, but I can describe the key imaging views and anatomical landmarks you should review when crossing the interatrial septum for PFO closure.
ICE Imaging Protocol for Transseptal Navigation During PFO Closure
ICE provides real-time visualization of the interatrial septum and is appropriate for guiding PFO closure procedures 1, 2. The technique offers several advantages over TEE, including elimination of general anesthesia requirements and superior imaging quality due to the proximity of the ICE catheter to cardiac structures 3, 4.
Standard ICE Catheter Positioning and Views
Position the ICE catheter in the right atrium to obtain optimal visualization of the interatrial septum 1:
Home view: ICE catheter positioned in mid-right atrium provides visualization of:
- The entire interatrial septum
- Fossa ovalis region
- Superior and inferior vena cava openings
- Aortic root as an anterior landmark
Key anatomical landmarks to identify:
- Septum primum and septum secundum separation (defines the PFO tunnel) 5
- Aortic root (anterosuperior reference point)
- Superior vena cava (superior border)
- Inferior vena cava (inferior border)
- Coronary sinus (posteroinferior landmark)
Specific ICE Views for Septal Crossing
The bicaval view (approximately 90° multiplane angle) is essential for visualizing the septum and guiding wire/catheter passage 6:
Pre-crossing assessment:
During crossing:
Sheath exchange guidance:
- Visualize large-bore sheath advancement over wire
- Confirm sheath tip position in left atrium
- Monitor for air bubbles during exchanges 9
Alternative Technique for Difficult Anatomy
For complex long-tunnel PFOs where standard wire crossing is difficult, the "push and easy" technique combines ICE with a pressure-sensing catheter 10:
- The pressure-sensing catheter provides:
- Real-time pressure feedback confirming left atrial entry
- Enhanced support and maneuverability
- Ability to navigate tortuous tunnels
- This approach achieved successful closure without radiation exposure 10
When PFO anatomy is unclear on ICE, use a Swartz catheter to apply physical pressure on the right atrial septum to identify the communication 5. This mechanical probing technique can reveal the PFO when separation between septum primum and secundum is not evident on imaging alone.
Critical Safety Considerations
Continuous ICE monitoring throughout the procedure is essential for detecting complications 1:
- Pericardial effusion/tamponade (most critical complication)
- Thrombus formation on catheters or septum
- Air embolism during sheath exchanges
- Malposition of delivery system
ICE measurements correlate well with TEE (r=0.97-0.98) for defect sizing and balloon-stretched diameter 4, making it a reliable standalone imaging modality that eliminates the need for general anesthesia in most cases 3, 4.
Anatomical Variations Requiring Attention
ICE can detect additional anatomical variations in 12.3% of patients not identified on initial TEE 3:
- Multiple fenestrations
- Prominent Eustachian valve or Chiari network
- Tissue strands crossing the defect
- Anomalous pulmonary venous drainage (particularly with sinus venosus defects) 8
Post-Crossing Device Deployment Monitoring
After successful septal crossing, ICE guides device deployment by providing "en-face" views of the septum 6:
- Monitor device positioning on both atrial sides
- Confirm proper seating without compression of coronary sinus or vena cavae
- Assess for residual shunts immediately post-deployment
- Verify no interference with adjacent structures
The combination of ICE guidance with fluoroscopy provides optimal safety while minimizing radiation exposure 10, 7. In straightforward anatomy, some operators successfully perform PFO closure with fluoroscopy alone using "standby ICE" (91% success rate), reserving ICE for complex cases 7.