Vive La Resolution! HD 76-micron High-Definition (Hi-Def) Detector

As Interventional Cardiology becomes more complex, the need for better imaging capacities increases. Dr. Salman Arain, Associate Professor of Medicine at the University of Texas Health Sciences Center in the USA, explains how Canon’s Alphenix Hi-Def Detector can provide solutions for better diagnosis, procedure planning and execution, troubleshooting in complex cases, and can even contribute to the development of new procedures.

Meaningful Innovation Overcomes Challenges

“We operate within an increasingly complex world in the Cath Lab,” remarked Dr. Arain. “Our target vessels are smaller. Interventions are more complicated and the tools that we are required to use have become more intricate.
Angiography alone is limited in several ways to treat to treat these fairly complex legion subsets.”

“Some solutions have been proposed, but most of these lack real-time applicability, especially during the manipulation of catheter, guidewires and devices,“ he continued. “However, higher resolution of the image improves vessel anatomy, leads to better procedure outcomes, and improves safety in the Lab.”
To address these challenges, Canon Medical developed the Hi-Def imaging detector with a 76 micron pixel, high resolution imaging modes. In comparison, the standard flat panel detector (FPD) in conventional angiography systems is in the range of 150 - 200 micron pixel resolution. The Alphenix Hi-Def detector provides more than two times higher spatial resolution than any other available system. Images can be zoomed up to 1.5 inches at 76-micron resolution without losing image quality, helping clinicians visualize fine details, anatomical structures and deploy devices with accuracy and confidence.

“With Hi-Def you can go into 3.0 inches, 2.3 inches and up to 1.5 inches field-of-views (FOVs) and with this you can actually see the different stent struts, for example” said Dr.Arain. “You simply push a button to get Hi-Def, and push a button to come off Hi-Def. It allows you to do diagnosis and better procedure planning, procedure execution, troubleshooting into complex cases, and even the development of new procedures,” he added. “I have many examples of how successful Hi-Def has already been in my workflow.”
Figure 1: The unique Alphenix Hi-Def detector offers multiple standard modes at 16”, 12”, 10”, 8” 6” and 4.3” FOVs and three additional Hi-Def modes with 3” 2.3” and 1.5” FOV, delivering increased spatial resolution without interruption of procedure workflow.

Diagnosis and Procedure Planning

“This is a 75-year-old patient presented with ischemia, in-stent re-stenosis and a non-ST Elevation MI. After multiple attempts and different guides, we could not get any guide to engage the RCA ostium. With the Hi-Def view, we could see what the problem really was – Not only does he have a stent with proximal under expansion, there is also a broken wire that is hanging out at the ostium. Apparently, he had an intervention done outside the hospital and no one told him, but the wire broke in place. In fact the wire was hanging in the aorta somewhere (Figure 2A)” explained Dr. Arain. “Under Hi-Def guidance, we passed the hydrophilic wire, and it went through the under expanded portion (Figure 2B). Once it passed through, I switched to lower resolution view in the FPD(Figure 2C). I didn't have to use a separate piece of equipment.”
Figure 2: (A) Hi-Def mode reveals a broken wire and under expanded stent from a previous intervention that impedes the guide engagement at RCA ostium. (B) A hydrophilic wire successfully crosses the stent under Hi-def guidance. (C) Standard FPD FOV is switched from Hi-Def FOV once the wire crosses the under expanded stent to continue to intervention.

Procedure Execution

“At the time of intervention, we switched to Hi-Def again. We completed this case by performing a high-pressure angioplasty and expanded the stent. We used the guide extender and a second wire provided more stability. This was possible to do accurately, because of Hi-Def imaging. (Figure 3).
Within the same case, we not only used Hi-Def to diagnose the problem, but also treat it in the most optimal way.
Figure 3: (A) Hi-Def is turned on during the intervention to position the stent for optimal outcome. (B) A stent is expanded by high pressure balloon under Hi-Def. (C) Switching from Hi-Def mode to standard FPD mode is done seamlessly to complete the procedure.

Troubleshooting: The Microcatheter That Wouldn’t Pass!

“This issue with a microcatheter that just doesn’t go forward comes up often when we are doing complex PCI or CTO”remarked Dr. Arain. “This patient has multiple stents, history of bypass, failed bypass, multiple CTOs and recurrent in-stent stenosis. We were able to get a wire across, but when we were trying to advance our microcatheter, it failed to cross. We switched to Hi-Def mode and found that the tip of the microcatheter was getting caught on the edge (Figure 4). We solved the problem by passing a 1.0 balloon then a 1.5 balloon angioplasty and smoothed out the transition (Figure 4). After angioplasty, we took the same microcatheter and it slipped across easily. (Figure 4) We then switched out to FPD mode with a wiggle wire, we could then identify the area that needs treatment and complete the intervention.”
Figure 4: When a microcatheter was unable to advance, Hi-Def mode was switched on and it successfully revealed that the tip of the microcatheter was getting caught on the edge (A). Balloon angioplasty was performed resulted the same microcatheter to cross easily (B) in FPD mode. Switching back to Hi-Def when deploying overlapping stents (C). The patient underwent successful intervention as shown in standard FPD view (D)

Development of New Procedures

“We have also seen some excellent use of Hi-Def in peripheral vasculature. Here, Hi-Def showed that the anterior tibial stent was fractured, but the stenosis was in the proximal edge. This case demonstrates that in you can use all of your other functions, such as digital subtraction and roadmap etc. while in the Hi-Def mode. (Figure 5)”
Figure 5: The 3" x 3" Hi-Def mode (B) showing complete fracture and avulsion of one of the previously placed stents which was not visible under the 12" x 12" FOV FPD mode (A). The Hi-Def mode was subsequently used to accurately size and precisely deploy a stent across the stenosis within the popliteal artery (C, D).

“Hi-Def allows me to do diagnosis and better procedure planning, procedure execution, troubleshooting into complex cases, and even the development of new procedures.”

Dr. Salman A. Arain, MD, FACC, FSCAI.
Associate Professor of Medicine at the University of Texas Health Sciences Center in the USA
“We have worked on many hands over the past two years.
Patients often present with scleroderma. A lot of them have small vessel disease at the level of the ulnar, or the palmar arches and sometimes in the digits. What we found out is you can use some of these more contemporary tools to get into these smaller branches and angioplasty them.

This is a young woman who has had a painful non-healing ulcer for over a year. Each digit is supposed to have two palmar branches, but she has only one in the middle finger and even that has a total occlusion (Figure A). We switched to the Hi-Def with a guidewire to cross, then a tip injection to confirm the wire was in the true lumen of the vessel. We did a 1.0 balloon angioplasty and drove the knuckle wire to cross the distal digit CTO.”

“It's not amazing because I did it. It's amazing because we have the tools and the technology to do this. So, not only do you need the right kind of wires and microcatheters. What you also need is the right kind of visualization technology to see these.”
Figure 6: Chronic total occlusion in the middle finger (A) Guidewire advanced to the distal digit under the Hi-Def mode (B). A tip injection from the microcatheter under the Hi-Def confirmed the wire is in true lumen (C). Final confirmation of revascularization in standard FPD view (D). The middle finger was completely healed (F) a few months later compared to the ulcer prior to intervention (E).

Redefine Intervention with Hi-Def Imaging

“Hi-Def 76 is an essential tool in the Cath Lab. As you do more and more complex procedures, you don't have to rely on the traditional imaging techniques. We can go one better.
Hi-Def is an alternative to IVUS and ideal for when vessels are even too small for IVUS. We have on-demand Hi-Def magnfications, across all imaging types” said Dr. Arain. “The improved visualization allows you to see devices better, image them, and deploy them better. it allows you to manipulate wires better into microscopic channels that are not even visible. And it leads to improved technical outcomes.”

“And last but not the least,” Dr. Arain added. “We have actually found that the total radiation doses decrease because we can see better and focus on such a small area of the heart.” //

The clinical results, performance and views described in this case study are the experience of the clinician. Results may vary due to clinical setting, patient presentation and other factors. Many factors could cause the actual results and performance of Canon’s product to be materially different from any of the aforementioned. //

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