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Step by Step Guide to OCT

Dr. Ramesh Daggubati

Clinical Professor

East Carolina Heart Institute, US

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Ramesh Daggubati

Thank you for this opportunity and I think I and Mona, we both are given a task of trying to catch up with the time. So that is fine. Do the best you can. So I agree a little bit about the IVUS still remaining but first of all there is nothing routine in the imaging right. You have to understand that even FFR is only done less than 50% of times in America not because of we do not believe in FFR, any patient that comes to the cath lab probably have to have a stress test prior to coming to the cath lab. So that is why FFR is not done in all the patients. So you will never come to 100% FFR. You will never come to 100% IVUS-OCT usage, because only 20% of the times you need imaging in most of the cases and that is the most complex PCI. So, this session is when it is asked to be step by step guide to OCT, not how OCT is superior to IVUS, it is very simple. If you do not believe my words (100) go back to the black and white TV base. While we are trying three dimensional, all high definition color televisions now right? Whatever IVUS is seeing, actually OCT can show better. Deep penetration that actually you can adjust the area field of view and you can see behind the vessel wall as well. So, I do not think that this a debate even in our own cath lab my technicians who will not understand what I am talking about an IVUS when I show the OCT, they say Oh yea! I can see what you are talking about. Even a medical student can diagnose an ICH dissection. So here we are going to talk about OCT and I am going to complete this skit, the pre intervention assessment stent deployment and complications both procedural because as I said in one line whatever I will show, OCT will show better and already I am sharing about how (200) imaging is important in seeing the stent opposition, dye-ICH dissection, necrotic lipid core and all that. So how you acquire the image? So this is in America there is one machine that is available it is St. Jude and I am not sure in India how many different types of machines you have. In Europe and in Japan you have both St. Jude and Thermal. So the two IVUS machines that I have worked with different type of IVUS, trying to develop an animal lapse rights few months ago. So that is not available yet. So, there is a consult and that is VoLumen office and now we have poor registration with FFR with the imaging catheter that can show exactly where the FFR is how much it is in correlating with the lesions that you can see by OCT. It is a rapid exchange catheter. It is much easier and it is the imaging catheter is called dragon fly. So, we have to slush with the contrast (300). You have to make sure that there is no blood in the vessel wall. In the past, we used inflator balloon and do OCT run because that was the best way to do a blood less coronary artery. Now we do not have to do that. We have injectors that can deliver a contrast, it is fixed this rate and you can do the pull back automatic. You have do manual pullback, yes very rarely if the stenosis is very tight and it is not coming back doing manual pullback. So the pullback length is about 7.5 to 5.4 cm depending upon you can adjust that pullback length and usually pulls back in 3 seconds or 2.1 seconds, much faster than IVUS. So, first before you can into the body, you can damage this whole thing. Everything is expensive. I tried to put a dot once and tried to remove it, and I damaged (400) the doting point of that pins and that caused a couple may be $ 10 to 20,000, I do not even know. So, I personally tried to pull it out and pulled the entire thing out that is not good. So, do not touch it, so let your technician do it or you can learn and try to be very careful after that do not touch doting part and let the technician take your blame for me. So then first the do settings that you have, take a 3 cc contrast and then attach to the catheter dragon fly and purge the catheter with contrast completely. There is a very small hole, and the laser lens is actually proximal to the tip of the catheter, artery is not working and anyhow the contrast will come out actually just where the lens is distal to the lens. So here is the imaging code and that optical lens and distal to that you actually you can see the contrast coming out (500) and that will actually let you guide it, is easy to load the IVUS on to the wire, so back loading the wire is somewhat difficult and you can do that if you can help by purging the catheter. So then connect the catheter with the dot, you can set the flush injection and how many people use automatic injectors and not probably many. It is easy to have that is not the thing, you have to inject with a lot of force manually. I like automatic injector for left coronary 4 cc per second for total of 14 cc and right coronory 3 cc per second, for a total of 12 cc and if it is a large vessel you have to take more 4 cc per second, total 20 mL. So what is important is because it is large vessel, do not make it 6 cc, 4 cc is enough, but you have to wait for longer injection duration. So the key to adequate clearance is time and not volume and (600) select the pullback length and image acquisition method that you want as I said, you can increase the field of view if you want. If we do not want it that is fine. What is more important for us is what actually is close to the vessel wall, and so that is why do not increase the field of view. So, it is a very high resolution acquisition at 54 mm in about 3 seconds, a long acquisition about 2.1 seconds you can get 7.5 cm. So then what is the next step after doing it out at the body, back load advance the catheter in a standby mode, standby mode is on the console, you select that and advance the catheter into the area of interest meaning into the pulmonary artery beyond the lesion that you see because it is pulling back, so you have first go beyond the lesion. If it is 99% occluded or functional CTO do not try to OCT, do not try to do IVUS you do not need that. (700) First balloon it, restore the element of blood flow and then you can play with these catheters, otherwise the patient will become ischemic and hemodynamic problem. So then engage the guide catheter as I said in the past we had a balloon but now we do not have, so have good engagement of the guide catheter into the pulmonary artery, avoid side walls, administer nitroglycerin because you might create ischemia, you want to make sure that the patient does not become ischemic and then enable live image and inject the flush period to deliver nitroglycerin and ensure adequate blood clearance. You have to make sure. So do not waste contrast what I usually do is plan your angiographic view in such a way, set it up that you are not planning, keep it in pending imaging mode and so you have to clear set up, if you use OCT once and then you want to image next, you wasted 20 cc of contrast, rather than that (800)while you are injecting contrast, I actually cine so that with one time you capture both OCT as well as angiogram and look for any complications. If there are no complications on the OCT and if you do not see a distal perforation from the wire, you are done. That is your last picture and you can take it out and before you can purge the whole OCT catheter, just minimize this signal damage. So here it is not very clear the guide is engaged. There is a distal proximal marker, the distal marker is there, so this is the length of how much it is going to pullback and the wire is all the way distal to that and you do not want to come out of it to make sure that is not. So there is a 20 mm apart from the tip to the lens. So as I said, press and enable the OCT dot or consult to calibrate. Cine, enable and inject or you can do enable first and you will give you enough time and then (900) as I start injecting and cine gets the same time. So this is what you get and familiarize yourself with the distillate that is all step 2 step set up, there is nothing difficult. It will give you a beautiful picture and then you will learn about the software. The software will give you everything, it tells you what is the diameter, the MLT, what is the area of stenosis and what is the areas itself and so minimal lumen area and the lesion is 2.51, if it is here 5.9 distally and proximally it is 6.14 an area of stenosis is given over here and it tells you what size your stent should be and you can measure it and know that. So you can unlock and you can measure if you do not like the electronic software system, you can draw your own and you can ask your technician to draw it very clear. So you put a 3-D (10

  • Heart Attack
  • MI
  • ECG
  • Hypertension
  • Bypass Surgery
  • Stent

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