Pulmonary AVM Embolization

1. Preparation

1. Informed consent
2. Sterilely prep and drape patient’s groin
3. Timeout
4. General anesthesia (patient is a minor)

2. Access

1. Right common femoral vein is punctured under ultrasound guidance
• Use great saphenous vein as landmark in place of fluoroscopy
2. Advance wire to IVC
• Identified as placement of the wire directly to the right of the spine on imaging
3. A 5-French pigtail catheter was threaded over a Bentson wire into the right atrium
• EKG monitor used to check for ectopic beats upon entry into the heart
• Positioning was considered accurate based on the pressure readings

3. Measuring Pressures

1. Pressure was recorded in the right atrium (11/8 with a mean of 9)
2. Using the curved stiff back end of the Bentson wire, the catheter was then advanced into the right ventricle
3. Pressure was recorded in the right ventricle (23/6 with a mean of 11)
4. Distal end of the catheter was manipulated into the pulmonary artery
5. Pressure was recorded in the pulmonary artery (22/13 with a mean of 17)
6. Heparin 3000 units were administered intravenously

4. Mapping Left Lung

1. Contrast injections with digital imaging over the left lung
• Right anterior oblique projection
2. The left lung’s two simple pulmonary arteriovenous malformations were visualized
• The left lower lobe contained one small PAVM previously discovered by CT (feeding artery 2 mm in diameter)
• Second lesion in the middle of the lower lobe (not suitable for embolization due to size)
• Based on size and location, feeding arteries determined to arise from the left lower lobe anterior branch
3. No other PAVMs were appreciated in left lung

5. Mapping Right Lung

1. Curved stiff back end of the Bentson wire used to return to the right pulmonary artery for angiography
• Left and right anterior oblique projections
2. The right lung’s PAVMs were visualized
• One simple lesion was appreciated at the right lung apex (feeding artery 2.5 mm in diameter)
• A small lesion at the right lung base (not suitable for embolization due to size)
3. No other PAVMs were appreciated in right lung

6. Embolize AVM in Right Lung

1. Pigtail catheter was exchanged over a Rosen wire
2. 90-cm long 6-French sheath with a coaxial 125-cm long Berenstein catheter
• Allows access to the right upper lobe PAVM
3. Catheter advanced and placed distally to feeding artery, adjacent to sac
4. PAVM embolized with 5-mm Amplatzer Vascular Plug version 4 (AVP4)
• Consists of a Nitinol mesh
5. Occlusion confirmed via angiography

7. Embolize AVM in Left Lung

1. Catheters manipulated into left pulmonary artery
2. Coaxial catheter system advanced into first feeding artery within anterior lower lobe (diameter 1.7 mm), and eventually, the sac
3. Location confirmed with contrast injection
4. PAVM embolized with 4-mm AVP4
5. Occlusion confirmed via angiography

8. Closure

1. Cathers and sheath are removed
2. Hemostasis is achieved at puncture site with manual compression 5–10 minutes

9. Follow-Up Plans

1. 6–12 months, classically for repeat CT scan
• Because patient is a minor and AVMS are relatively small, may be less agressive getting CT scans
• 3–5 years (unless planning on getting pregnant)