In this episode, host Dr. Aparna Baheti interviews interventional radiologist Dr. Michael Cumming about his Chiba needle technique for difficult CTOs, including how to perform the technique safely and how to approach complications.

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SHOW NOTES

Dr. Cumming is one of three interventional radiologists at a private practice OBL in Minneapolis, MN. He treats patients with significant vascular disease, and has developed an approach to tackle heavily calcified chronic total occlusions (CTOs). He first used this technique on a patient with superficial femoral artery (SFA) CTOs, rest pain at night and short distance claudication. The patient was a poor candidate for surgical bypass. He began the case using the conventional technique (glide wire) but after failing twice because the wire wasn’t stiff enough, he asked for a Chiba needle. He used extravascular ultrasound (EVUS) and got part of the way through the SFA occlusion, but couldn’t completely cross the lesion because the needle was too short. He then went looking for a longer needle, and found a 65cm Chiba on the Cook website.

Dr. Cumming explains his escalation algorithm, which he uses in every revascularization case. He starts with glide wire (straight or angled), and if he gets to the point where the wire loops on itself, rather than advancing the wire and risking subintimal reentry, he stops. It is important to him to remain true lumen if possible. Next, he tries the back end of the glide wire. Third, he puts an anchoring balloon in and tries again with the back end of the glide wire. If none of these options work, he will either try his Chiba technique or try a retrograde approach from a tibial artery. If he spends more than 5 minutes on any of these steps, he moves on to the next step. He emphasizes the importance of having a plan ahead of time, rather than trying to figure out your next steps mid procedure.

For the Chiba technique, Dr. Cumming uses the 65cm Chiba (with or without stylet) through a 40cm Kumpe catheter. He advances it over an 018 nitinol or stainless steel wire. He shapes the Chiba needle based on whether he is trying to cross a lesion or enter the ostium of an artery. Using fluoroscopy, often in the orthogonal plane, he advances the needle by spinning it. Using this technique is relatively safe if you know where you are in the vessel and go slowly. Nevertheless, he says complications will still occur due to the severity of vascular disease. If the needle or wire goes extraluminal or perforates the artery causing heavier bleeding, he always has a plan. He uses balloons to try to tamponade the bleed, and occasionally injects thrombin to the area using a spinal needle. The most dangerous complication is heavy extravasation below the knee in the calf compartments that can lead to compartment syndrome.

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RESOURCES

Twitter:

@drcumming

LinkedIn:

https://www.linkedin.com/in/drmichaelcumming

Chiba needle:

https://www.cookmedical.com/products/ir_dchn_webds/