Dr. Shivangi Kothari is an Associate Professor of Medicine and the Associate Director of Endoscopy. Dr. Kothari has clinical expertise in interventional endoscopic ultrasound, advanced therapeutic ERCP, esophageal endotherapy for Barrett's, double balloon endoscopy, my most favorite procedure, and pancreatic ovillary disorders. Dr. Kothari's interest in academic medicine has led her to practice evidence-based medicine and conducting multiple research projects. Her research interests include development of EOSFNA techniques, endoscopic ablation for Barrett's esophagus, and the evaluation of new devices and technology in the diagnosis of pancreatic ovillary disorders. Dr. Kothari is an active member of many scientific GI societies with several national, international gastroenterology committees, and is a reviewer for many journals, and most importantly, which I just found out a little while ago, she actually belongs to my alma mater, my same medical school in Bombay. So with that, Dr. Kothari, thank you very much for doing this with us, and the camera and the mic is yours. And continuing with the EOS interventions, these are my disclosures. I will be talking about techniques for EOS-guided pancreatic fluid collections, as well as some tips and tricks for management of EOS-guided celiac plexus blocks, as well as EOS-guided fiducial placements, discuss techniques for EOS-guided liver biopsy, and for EOS-guided portal pressure measurements. So talking about pancreatic fluid collection drainage, as Dr. Holt very nicely laid out, select your patients, make sure they don't have a history of a pancreatic cystic neoplasm, and it's truly a pancreatic fluid collection with a history of pancreatitis, and the collection is symptomatic, either with an infection or causing mass effect. The collection has a mature wall, has a close proximity to the gastric and duodenal wall. Review the imaging prior to hand, check for coagulopathy, and a multidisciplinary approach is key in managing these patients and working closely with your interventional radiology and your surgical colleagues. So in the management of pancreatic fluid collections, the two main steps are, first is creating the endoscopic transluminal drainage, whether that is with placement of double pigtail stents under EOS guidance, and now with the advent of lumen-opposing stents, the procedures have certainly gotten quicker and shorter, and we will talk about both those aspects. And then the step two is, if the patient does have a significant necrotic component to the fluid collection, or it is a wall of pancreatic necrosis, that doesn't improve with just establishing transluminal drainage, then those require direct entry into the cavity with endoscopic debridement with various tools, such as snares, baskets, forceps, whatever it takes to achieve clinical success. So set up for the EOS-guided double pigtail stent placement, of course, this is done under EOS guidance, 19-gauge FNA needle, guide wires, I prefer the two-guide wire technique, wire-guided dilation balloon, plastic double pigtail stents, and of course, a fluoroscopy setup. These are usually done under anesthesia support so the patients are comfortable. Good Doppler evaluation of the cyst is essential to make sure that there are no blood vessels in the needle path, there is no pseudoaneurysm, and you're not dealing with a malignant cystic degeneration of a tumor and you've adequately evaluated the pancreas. The needle is advanced into the cyst and a guide wire is then advanced through the needle and coiled a couple of times, you want to make sure it's got a couple of coils within the cystic cavity to have a stable position, and then balloon dilation of the fistulas tract is performed. I usually like to not go beyond eight millimeters of the initial dilation just to minimize the risk of perforation, and then you advance a second guide wire. There are studies that have reported the use of cystotomes or even a needle-knife catheter with the tip of the needle-knife turned backwards to apply cautery. The first pigtail stent goes over the first guide wire, and then you put the second pigtail stent, choices between seven French or 10 Frenches. I usually prefer to put the seven French first and then the second stent is a 10 French stent because with the wire in the channel, it could cause a lot of friction in placing the stents. This is the CT 10 days post-drainage, and as you can see, the fluid collection has resolved. This is a patient with post-VIPL pseudocyst drainage that we performed along with my mentor, Dr. Banerjee, and the scope is advanced into the afferent limb. Here you can see the needle is advanced into the collection, and we prefer to pacify it a little bit. I just like to inject a little bit of contrast and make sure that the cyst is not perforated or anything, and then a guide wire is advanced into the collection and balloon dilation of the tract is performed. The first pigtail stent is placed over the guide wire, and then a second guide wire is advanced alongside the stent, and a second pigtail stent is placed. In this case, two seven French stents were placed. I usually prefer a four to five centimeter length of the pigtail stents. With the advent of the lumen-opposing metal stents, the endoscopic drainage of these collections has become, as I said, much easier, faster. It's a one-step device with the cottery attachment, and the stents come in a 10 millimeter, 15, or 20 millimeter diameters. If I do know there is a significant necrotic component to the cyst, I prefer to put the 15 and now the 20 millimeter stents. If it's a pure fluid collection, you may want to put a 10 millimeter stent. Always endoscopically check where you are placing your stents, especially if you're planning a necrosectomy later on, to make sure that it is in the mid-to-distal portion of the stomach and is easily endoscopically accessible. You don't want to put it too high in the cardiac, because it will make it very difficult to then endoscopically access the cavity. In this video by Dr. Ben Moeller, he goes very nicely over the steps of a LAMS deployment. You insert the sheath into the channel of the linear EUS scope. You need a therapeutic linear for this. You will lock the sheath to the port, and then the sheath hub is unlocked and the cottery is attached. And this is all done under EUS guidance, the entire placement. Then you slowly advance the sheath down, and you can see it by the arrow in the top right corner. And now using cottery, you're going to puncture the sheath. These are the settings you use for the HOT LAMS placement, and you're going to tap on the yellow pedal to advance the sheath into the cyst cavity. And then detach the cottery, and you're going to lock the sheath hub and unlock the safety pin, and deploy the first, unlock the flange, and then deploy the distal flange of the stent within the cyst cavity under EUS guidance. And you can see the stent is beautifully deployed. Now we're going to unlock the sheath hub and slowly pull it backwards to approximate the stent to the bowel wall, and then you're going to relock the sheath hub. And now deploy the proximal flange within the scope. This is the technique I prefer, where you deploy it within the scope channel and then slowly move the scope tip away while pushing the stent out of the scope channel, and you see immediate decompression of the fluid through that. This is the LAMS placement in a walled-off pancreatic necrosis. This is actually a tip of the iceberg. This was a huge cavity over 15 centimeters and a significant amount of debris within the cyst, and the lumen-opposing metal stent was placed under EUS guidance. Here you can see the stent is entering the cavity, and the first flange, the distal flange, is deployed. And then under endoscopic guidance, slowly the proximal flange is deployed, and you can see purulent fluid draining immediately out of the stent. Balloon dilation of the LAMS is performed, and you can see all the necrotic tissue within the cyst cavity. I personally do not prefer to perform a necrosectomy at the index LAMS placement. I like to bring the patient back. In comparison of plastic versus LAMS, certainly the procedures are shorter, and some studies have suggested lesser need for interventions with the LAMS. However, there is a significant risk of bleeding and pseudoaneurysm with the LAMS placement if they're left in for over four weeks. So they should be removed in a timely fashion within three to four weeks. Ideally, you want to get a scan within two to three weeks, see if the collection has resolved, and then remove the LAMS. I usually like to put a double pigtail stent within the LAMS just to minimize any risk of delayed bleeding. And there is a cost difference between the plastic stents and the LAMS, and you want to keep that in the back of your mind. So the step two in these patients is a necrosectomy if the patient has significant necrotic debris. If plastic stents were placed, remove them, dilate the tract. If LAMS was placed, then you can directly endoscopically do the necrosectomy. Use snares, rat tooth forceps, whatever it takes. Lavaging the cyst. Use of diluted hydrogen peroxide has been reported in some studies, and experts have recommended to avoid PPI, to let the gastric acid help with the ongoing liquefactive necrosis of the tissue. I personally prefer a therapeutic gastroscope and a snare. That's my go-to. And a lot enough time. I usually allot myself for about two hours, and of course, whatever it takes to get a clinical resolution. Here you can see from the prior video, the patient was brought back a week later for endoscopic necrosectomy. I personally, as I said, I prefer to go with the snares. There are newer devices, such as the endorotor device, baskets, rock nets that have been reported to be used to pull the necrosome into the gastric cavity, and you keep going at it till your clinical resolution is achieved. So this is the before, and this is after two hours of hard work. And this is what you want to see at the end of all your efforts to help the patient. Make sure you are mindful of the complications whenever you use these devices. Bleeding is a real risk. This patient had a significant bleeding from the lambs. And here you can see bleeding within the cyst cavity, and patient did require IR intervention for that. This is a view through the lambs of a perforation, and the lambs was removed, and the fistula successfully closed with an over-the-scope clip. So some pearls for management of fluid collection. Decide whether you're going to put double pigtail stents, lambs. You've reviewed and carefully selected your patient. Bring them back within a week, and then every 3 to 10 days if they do require necrosectomies. Confirm resolution with CT imaging. Remove the stents in a timely fashion. And of course, a multidisciplinary care is essential. Work with your team. As in this case, you can see a patient had a large wall of pancreatic necrosis, and there are the percutaneous drains, and you could see the drains when we did the endoscopic necrosectomy. And this is the final result, and this is the after, and that's what you want to achieve for. So talking about the EOS-guided fine needle injection, we will talk about pain management as well as fiducial placements. Dr. Holt mentioned EOS-guided celiac plexus block and neuralysis are used. Plexus block is for patients for benign indications such as chronic pancreatitis, and you use a combination of bupivacaine with steroids such as triamcinolone. Celiac plexus neuralysis is for cancer patients, and it's a combination of bupivacaine with dehydrated alcohol. EOS allows for real-time imaging and visualization, especially of the celiac ganglion and also Doppler assessment of the structures. One of the biggest side effects of this is hypotension. So make sure the patients receive hydration with at least 500 mL to 1,000 mL of normal saline prior to the procedure. Patients are given antibiotic prophylaxis. This requires adequate sedation. Again, I usually prefer to do these under general anesthesia, and you could use a 19-22 or a dedicated 20-gauge needle that is available. When you enter the celiac area right here, make sure you first aspirate to confirm absence of any blood return, and after every injection, the needle should be flushed. So there are a couple of approaches of performing a celiac plexus block. This is the anterior approach where you're injecting right anterior to the celiac axis, and then there's a bilateral approach where you turn right of the celiac artery and then turn left, and injection is performed on either side. In celiac ganglion neuralysis, here you can see we visualize the ganglion, then injection is performed directly into the ganglion to perform neuralysis. The needle is always first flushed prior to any celiac plexus neuralysis, so you flush it with saline. This is a patient with a pancreatic body mass that was referred for celiac plexus neuralysis, and as you track the aorta downwards at the G-junction, you can see the celiac artery take off, and then the needle is advanced after Doppler evaluation. You want to adequately apply Doppler and make sure there are no blood vessels in the needle path, and then always aspirate as soon as the needle enters into the celiac plexus to make sure there is no blood return. And then injection first is performed with bupivacaine. We usually use 10 ml of bupivacaine followed by dehydrated alcohol, and you can see haziness appear within the celiac plexus area from the injection after a successful neuralysis. Coming to fiducial placements, metal fiducial markers into tumors allow real-time tracking of the tumor for targeted stereotactic radiotherapy, radiation therapy. Treatment is delivered to the tumor with high precession and decreasing any kind of damage to the normal surrounding tissue. And now with the advent of EUS, fiducials can be safely and successfully placed in pancreas, esophagus, celiac nodes, adrenal glands, and the colon. You want to place at least three fiducials in a non-collinear manner, and patients do receive an antibiotic prophylaxis. There is the backload technique and the preloaded technique. In the backload technique in this video by Dr. Bhutani, you can see the stylet is pulled back, and the fiducial is backloaded into the needle, and then the tip of the needle is sealed with bone wax. Here you can see the fiducial is being advanced into the needle. And then using the bone wax, the tip of the needle is sealed because you don't want the fiducial to fall within the scope channel, and the fiducial is then deployed into the tumor by pushing the stylet down. Now we have the commercially available preloaded fiducial needles, which make it easier to deploy fiducials into difficult patients, difficult lesions, and of course there is lower risk to support staff because they don't have to handle the dirty needle. Our group has reported a shorter procedure duration, the average time between fiducial placement with a preloaded fiducial needle compared to a backloader technique. In this animation created by our group in collaboration with the Rochester Institute of Technology, you can see how fiducials are placed using a preloaded fiducial needle into a pancreatic mass, and you just want to go to different areas of the tumor and the fiducial is deployed by pushing the stylet. Here you can see the stylet is being pushed down and the fiducial is deployed into the tumor successfully. This is a patient with a G-junction mass that is referred for staging of the tumor as well as fiducial placement. On EUS, the mass was staged at a T3, and then using the preloaded fiducial needle, fiducials are placed by pushing the stylet down and two fiducials were placed at the proximal edge of the tumor in this patient. Coming to EUS hepatology, as Dr. Holt mentioned, now EUS liver biopsy has been shown to be safe, minimally invasive, and the tissue yields similar to percutaneous and transjugular biopsies. So any patients who need a liver biopsy and also need EGD, EUS, or sedation, with the help of EUS, we can perform EUS liver biopsy. Make sure these patients don't have a coagulopathy, check the platelets, and don't have significant ascites. For the procedure setup, I prefer a 19-gauge FNB needle with a wet suction, perform bilobar biopsy, one puncture with three actuations, and send the specimen to pathology. Here you can see the needle is flushed with heparin, and then wet suction is created using two cc's of water, and the suction is not opened until we are ready to do our actuations. Using a transgastric approach, the left lobe of the liver is accessed. Always apply Doppler, and make sure there is no blood vessels in the needle path, and then check the span, usually about a three to four centimeter span is good to perform the biopsy. And now the suction is opened and three actuations are performed, and the specimen is then collected into a tissue cassette. The needle is flushed with heparin, and then washed with saline, and the fragments are then sent in formalin to histology. This is a patient with abnormal liver enzymes that were referred for a liver biopsy, and also had needed EGD for barrett surveillance. The EUS liver biopsy was performed, as you can see, and the tissue fragments on histology revealed atypical lymphocytic infiltrate and a low-grade B-cell lymphoma. He had further imaging, which showed diffuse lymphadenopathy, and the patient was referred to oncology and received chemotherapy. Coming lastly to US-guided portal pressure measurements, this gives the ability to directly measure hepatic and portal venous pressures. In the initial data, it has been shown to be safe and feasible, and can be concurrently performed with the US-guided liver biopsy. Here you can see the setup of the needle and the transducer. It is flushed with heparinized saline, and the needle is advanced into the middle hepatic vein under EUS guidance, and flushed, and three pressure measurements are obtained, and a mean is taken off those, and then the scope is further advanced down, and the needle advanced into the left portal vein, and again, it's the same thing. Three pressure readings are obtained, and the difference of the three pressures, of the pressure reading between the portal and the hepatic venous pressure is the portal pressure gradient. In this video by Dr. Akedia, you can see the portal pressure measurement in a patient with a nodular liver, and the concern is that the patient does have portal hypertension. Doppler is applied to evaluate. You track the IVC and turn leftwards and find the hepatic vein, and then the 25-gauge needle that comes with the device is advanced into the hepatic vein, and three pressure readings are obtained. The needle is always flushed with a little bit of 1 to 2 ml of heparinized saline to confirm that the needle is adequately within the vessel, and then the portal vein is accessed, and pressure readings are obtained. This is performed supine, and the pressure reading is obtained with keeping the transducer in the mid-axillary line, and as you withdraw the needle, you want to make sure that there is no bleeding with the Doppler. So in summary, a significant shift in management paradigms have occurred with interventional EUS. Make sure you adequately review the imaging, you have appropriate indication, a detailed informed consent, have the right equipment and staff and resources that you need to manage the case and the complications, and multidisciplinary management is critical in all these patients, and I think the interventions with the help of EUS continue to grow. Thank you.

interventional endoscopic ultrasound procedures

pancreatic fluid collection drainage

celiac plexus blocks

fiducial placements

liver biopsies

portal pressure measurements