So we'll get started with this session with Dr. Bronte Holt. Dr. Holt is an interventional gastroenterologist at St. Vincent's Hospital and Senior Clinical Fellow at the University of Melbourne in Australia. And we're very excited that she's joining us so early in the morning. She commenced on her endoscopy fellowship at West Med Hospital in 2011, where she also obtained her PhD through the University of Sydney. And then she went on to join the Center for Interventional Endoscopy in Florida as an endoscopy fellow in 2013. Her endoscopic interests include diagnostic and interventional EUS, pancreatic and biliary ERCP, advanced resection and management of IBD. She's an NHMRC early career fellow and enjoys research and teaching through supervision of endoscopy fellows and PhD candidates. Bronte, thank you so much for being with us. And we look forward to hearing from you. So today I'm going to be talking about the indications for EUS therapeutic procedures. This is really the start of the program. And so I'm going to be going over a number of procedures today and then in further depth through the upcoming talks, we'll be talking about them in more detail. I have no financial disclosures to make. So as an overview of what I'll be discussing today, we're talking about EUS guided access procedures, including pancreatic fluid collections, biliary and pancreatic duct access and drainage, gallbladder drainage and gastroenteral anastomosis, as well as discussing endohepatology with portal pressure gradient and variceal therapy, and finally discussing indications for celiac plexus neuralysis. Firstly, starting with pancreatic fluid collections. Acute pancreatic fluid collections after interstitial pancreatitis or necrotizing pancreatitis in the early stages are usually unsuitable for EUS guided drainage as they don't yet have a well defined wall and they're often not quite ready to be drained. Whereas with time, as these mature, usually around the four week mark, both pseudocysts and walled off necrosis that develop after interstitial and necrotizing pancreatitis, respectively, will develop into a more defined collection with a well defined wall that is more suitable for drainage. Often patients will develop fluid collections and the question really is, does that need to be drained or not? And the answer is, if they're symptomatic, that's when we should be considering them for drainage and if they're an asymptomatic collection, then usually just a watch and wait approach is suitable. Some symptoms are really quite heterogeneous, they may include organ obstruction, either GI luminal or biliary obstruction, vascular compression, pain, infection, as well as nausea, anorexia, loss of weight and more sort of generalized symptoms. On EUS, we assess for suitability for drainage as well. So someone might have a symptomatic collection, but it's not yet EUS suitable, so it needs a defined wall to be adherent to the GI wall. There's no intervening structures, either vascular or organelle, and there's adequate space within the collection for a stent insertion. Typically, a collection needs to be three centimetres as a minimum to coil the wire or place the stents. But if the patient has a pre-existing percutaneous drain, that can be used to insufflate the collection, or you can instill the collection with some sterile water or saline to make it larger, as well as having a suitable scope position. So we tend to try and avoid passing stents through the esophagus, for example, and you need to have good apposition of your scope to the GI lumen. This is a patient of mine who had a collection that was about five centimetres in the unscented process, and I drained that with a lumen-opposing metal stent, you can see here, with rapid drainage of necrotic fluid from that collection. And that patient had a really quick resolution of their symptoms. This is another patient who also had a walled-off necrotic collection. You can see here in the top left, that's a coronal image of their stomach at the top here, and you can see the collection in the head of the pancreas, with collection with this connection of the two structures with a lumen-opposing stent. They had a direct endoscopic necrosectomy, and three weeks later, this is the cavity, which is really nice and clean and granulating, and the patient did very well after that. Moving on to biliary access with or without drainage. The indications for EOS-guided biliary access are really evolving and expanding. We started out by looking at biliary access after failed ERCP. It's also very useful in patients who have an inaccessible papilla for a traditional ERCP, and more and more it's been looked at in studies as primary drainage. The alternate to EOS-guided biliary access if an ERCP is not possible is a percutaneous transhepatic biliary drainage and surgical bypass. The great advantage of EOS-guided biliary access and drainage is it allows an internal route. Intra- and extrahepatic biliary ducts can be accessible. It can be done as a single procedure. There's no to minimal pain, no limitations to patients' ADLs, has a relatively short hospital stay, and also patients like it. It's cosmetically appealing, and they don't have to deal with management of a percutaneous drain tube. In a number of studies now, including systematic reviews and meta-analysis, there's a high technical and clinical success rate, and the safety profile is also very good with a major adverse event rate of less than 5%. When comparing EOS to percutaneous biliary drainage, it has a similar technical success rate. However, the clinical success is higher. There are fewer post-procedural adverse events, a lower number of re-interventions required, and it's been found to be more cost effective. As mentioned, there have been a number of studies now looking at primary biliary drainage by EOS compared to ERCP. There were three recent RCTs that randomized patients to one or the other, and it really showed that the technical and clinical success rate and the rate of re-interventions were very similar between the two techniques. The main differences were really based around the differences from ERCP. So with ERCP, there was a higher rate of tumor ingrowth into the stent, a higher rate of post-ERCP pancreatitis. Conversely, with EOS, there was a higher rate of stent migration and food impaction. I'm just going to show you, sort of try to maybe skip through a little bit of this. This is a patient who had a malignant biliary obstruction past the EOS scope down. The patient also has a D1, D2 luminal obstruction too. And they've got a mass which is arising right near the head of pancreas. And as we roll across on EOS, you can see this dilated, obstructed common bile duct. It has a bit of sludge in the bottom of it. And that's secondary to this malignant mass. The obstruction is also quite chronic. You can see this classic starry sky appearance to the EOS, which is an indication on EOS, again, of more chronicity of the obstruction. Punctured this dilated duct and aspirated with a needle to confirm location. Then under fluoroscopy, pass a wire towards the hilum. And then I might just skip through a little here. I'm able to. And then I'm passing, just done a cold tract dilation, followed by insertion of a fully covered luminal stent. I did this procedure a few years ago, and at the time we didn't have access to the smaller calibre luminal posing metal stents. But it shows nicely how you can get rapid drainage and decompression of obstructed systems through EOS guided biliary drainage. Moving on to pancreatic duct access and drainage now. The indications for this is if a patient has pain or acute pancreatitis episodes from a dilated obstructed pancreatic duct that's leading to pancreatic hypertension. It can also be used to internalise a pancreatic cutaneous or pancreatic enteral fistula. Typically, these patients have failed an ERP or they might have an inaccessible papilla. The alternative in these patients is looking at surgery, whether that's a pusto, phrase, or whipples, or ESWL, or it's sometimes done in combination, often done in combination with ESWL. The technical success is a little lower than with biliary drainage, but it's relatively good 75 to 90%, long term clinical pain resolution 60 to 80%, interprocedural complications 16%, and a relatively high long term stent dysfunction. Right, and about half of patients. This is a patient of mine who had a T1a pancreatic head cancer. She survived, just over 10 years, she presented with acute pancreatitis episode, and she was found to have this obstructing calcific stone in the body of pancreas at the transection site of the pancreatic cogenital anastomosis. Clinically, it looked like this was secondary to a stricture. So I tried to do an ERCP and I was able to get the colonoscope up to the anastomosis. However, I just couldn't find the orifice in amongst all of the stitches from the operation. So we went on to do an EUS and it showed a dilated duct of eight millimeters. And then I defined that by EUS injection past a wire and then a catheter into that dilated duct. And then you can see here the wire is going across and the catheter across into the jejunal limb. And then was able to do a rendezvous procedure and go down again with the colonoscope. I could then find the pancreatic jejunal anastomotic orifice and collect the wire and pull it through to perform an ERCP by the transoral route with dilation of the stricture and then placed a stent. The patient then went on and had ESWL to address that stricture, sorry to address the stone. They had a really good decompression of the duct with stent placement, then brought them back after they had ESWL, pulled the stent out and then did a number of balloon trawls to extract the stones. And then I placed a 10 French pancreatic stent and 12 months later pulled that out and the patient has done really well in the year since. This is now talking about EUS guided gallbladder drainage. The indication is acute cholecystitis in high risk surgical candidates. And there's been a number of studies really led by Anthony Tao in Hong Kong. And it's been compared to PTBD or percutaneous trans-hepatic cholecystostomy. And it's shown that the one year 30 day adverse event rate is lower. And there's a lower rate of reinterventions and unplanned admissions. It's also been compared to laparoscopic cholecystoscopy in a comparative sort of patient study cohorts. And it's shown a similar clinical and technical success rate compared to surgical resections in this very high risk surgical cohort. Just very short video here. This was from a few years ago now. This is a really high risk patient of mine. They had so many comorbidities, as we'd say, they weren't fit for a haircut. And they had a cautery assisted lumen opposing metal stent placed transduodenally. And they had acute cholecystitis, were very septic and unwell. We're not an ICU candidate, though, so we really wanted to get them out as soon as we could. And they had rapid resolution of their cholecystitis with this technique. Moving on to EUS guided gastroenterostomy. So here we're looking at connecting the stomach to an enteral limb, most typically the jejunal limb. There's a number of techniques to this. You can have direct jejunal puncture after insufflation of the jejunal limb with fluid. A balloon assisted puncture technique where a balloon that's passed transaurally can help identify that jejunal limb. Or a double balloon occlusion technique, which is a specially designed device which has double balloon, which includes a section of the jejunum, which is then insufflated with fluid. And that allows a puncture point for the gastroenterostomy. The primary indications are malignant gastric outlet obstruction or GU. Benign gastric outlet obstruction has also been studied. It accounts for about 10% of GU cases, and that might be due to things such as peptic strictures or pancreatitis. Small number of afferent limb syndrome cases also reported and increasingly used as a technique of bariatric bypass. Contraindications of whether there's, if there's diffuse cancer invasion into the site of the puncture, either on the stomach or the small bowel site. If you can't identify an appropriate small bowel loop adjacent to the stomach, or if there's luminal obstruction downstream to your puncture point or large volume ascites. Another type of enteroenteral anastomosis is EOS directed transgastric ERCP. This is in patients who have Roux-en-Y gastric bypass anatomy or other Roux-en-Y anatomy where ERCP can't be performed easily by a transoral route. The alternatives to EOS directed transgastric ERCP is the transoral route, which can be challenging in some patients. You can use a duodenoscope, enteroscope, pediatric colonoscope or balloon assisted ERCP. And another option would be a surgical approach that can be to create a gastrostomy into the excluded stomach or a laparoscopic assisted ERCP, which has a relatively high morbidity comparatively. Considerations on which technique to use really comes down to things such as the Roux limb length. If it's a really long Roux limb, then getting to it with a duodenoscope can be very, very challenging. And you might be the other option would be like a balloon assisted enteroscopy if EOS was not used. If the patient has a native papilla, then using a technique that enables use of a duodenoscope is really beneficial to help cannulation. The indication for ERCP and the likelihood that you might need to have repeated procedures. So having a route to be able to keep going back is very useful, as well as availability of local expertise and patient surgical risk. Moving on to endohepatology, looking at EOS guided portal pressure gradient. The EOS portal pressure gradient is the difference between the mean portal venous pressure and the mean hepatic venous pressure. And it's been shown to be the best predictor of patient outcomes in liver cirrhosis and predicts surgical morbidity and cancer risk. The rationale for EOS guided portal pressure is it's less invasive than transjugular wedged hepatic venous pressure, which is performed by interventional radiology. It obtains a direct pressure gradient between the portal vein and hepatic vein. It can be combined with other procedures that you're doing whilst there, such as variceal or gait assessment or liver biopsy. And diagnosis is also possible in patients with non-cirrhotic portal hypertension. There is increasing amount of data coming out and it shows that it correlates with the HVPG. It has a good technical success and safety profile. It correlates with clinical markers of portal hypertension and also can be combined safely with EOS guided liver biopsy. The indications are still really being investigated in this technique, but assessing response for beta blockers, assessing response to antiviral agents, assessing the risk for post-hepatectomy failure in HCC patients, identifying patients who have NAFLD and NASH who have increased portal pressures, and then enable earlier intervention whilst the disease is reversible. And the list goes on. Moving on to indications for variceal therapy with EOS guided glue with or without coils. As primary prophylaxis, this is really just in clinical trial setting. However, in patients who have had a bleed or have actively bleeding gastric varices, then the indications for use is with GOV2, which is fundal gastric varices or isolated gastric varices. The benefits of doing EOS over direct endoscopic puncture of gastric varices is it allows a direct puncture of the vessel. A target feeding vessel can be identified. And it's also feasible to perform with a limited endoscopic view in cases where there's bleeding. It can be combined with glue and coiling. If coils are used, it can allow a lower volume of glue, which reduce the risk of glue embolism and also allows treatment of larger varices. Finally, just talk about the indications for celiac plexus neuralysis. Indication is pain due to unresectable upper abdominal cancer. Most commonly we would use this for pancreatic cancer patients who are not resectable. The efficacy after one treatment is 80 percent. And the procedure technique is to prime your needle. You can use a CPN 19 gauge or 22 gauge needle. Prime it with a little bit of normal saline. Puncture the target site of the celiac plexus. Apply suction to ensure you're not within the blood vessel. And then sequentially inject bupivacaine or a long acting local anesthetic and absolute alcohol, followed by flushing the channel of the needle with a small volume of saline and withdrawing the needle. Thank you.

Dr. Bronte Holt

interventional gastroenterologist

endoscopic ultrasound (EUS)

therapeutic procedures

patient selection