Endoscopic Ultrasound: Potential and Limitations

TMED Blog

| 1 February 2024

Written by Alexandra McDonald, MSc 25' (Candidate)

Following a brief history of endoscopic ultrasound, Dr. Mandip Rai offered the January 25th, MGR audience a balanced dose of caution and hope. It was fascinating to see the importance of Endoscopic Ultrasound (EUS) grow as Dr. Rai described an explosion of EUS procedures from 2002 to 2019 and a 16% average annual growth rate in publications related to EUS between 1980 and 2020.1 In Ontario, the number of EUS procedures increased 17-fold from 2002-20112; with KHSC following this trend save for a dip as COVID spread through our community. Sharing hyper-local data connected the group, while Dr. Rai began to present a story of translational medicine, that each member KHSC community related to in some way. Here, we will highlight the research that Dr. Rai selected to demonstrate the efficacy of increasingly common EUS procedures and reveal how our speaker merged this data with his training and clinical experience to establish the necessity of standardized procedures and better funding.

EUS guided pseudocyst drainage was introduced as a game changer in interventional, as opposed to diagnostic, EUS. Dr. Rai showcased its elegance as compared to the multi-step, surgical method. By combining steps using platforms, EUS guided pseudocyst drainage minimizes the increased risk of leakage and perforation, a risk associated with every step in classic surgical intervention. Dr. Rai presented three studies, comparing endoscopic with surgical cystogastrostomy for pancreatic cyst drainage3, examining the step-up approach compared to open necrosectomy for necrotizing pancreatitis4 and a final study looking at surgical versus endoscopic approaches to treat infected necrotising pancreatitis.5 Dr. Rai used the success of EUS intervention in pancreatitis, measured by variables like reinterventions, length of hospital stay, and complications; to contextualize its potential in other realms.

EUS guided gallbladder drainage (EUS-GBD) is an alternative to percutaneous gallbladder drainage (PT-GBD), which Dr. Rai noted, may relieve some of the noted adverse effects, like pain and decreased quality of life, of the latter. EUS-GBD offers a solution to those with acute cholecystitis who are considered too risky for cholecystectomy. While a multicentre, randomised, trial comparing these methods showed better outcomes in the EUS-GBD group6, Dr. Rai emphasized the remarkable experience of the endoscopists, encouraging an assessment of generalizability in clinical settings, where experience is limited. He also cautioned that the follow-up times used in this study were not sufficient to understand long-term implications. Though EUS-GBD is a safe and effective alternative in some patients, its implementation also relies on the availability of lumen-apposing metal stents (LAMS) in both training and treatment spheres.7

EUS guided Bile Duct Drainage (EUS-BD) was similarly compared to its percutaneous counterpart. Dr. Rai included a Canadian multicentre study assessing EUS-BD as a first line modality. Though technical success was found comparable between EUS-BD and gold standard ERCP, Dr. Rai highlighted the 7 cases of stent misdeployment in the EUS group, a higher rate of complication than comparable studies from the same year. To further emphasize the importance of operator expertise, Dr. Rai noted that these Canadian results were more generalizable to non-research settings, where there is a shortage of EUS-BD dedicated devices. He demonstrated why it is necessary to dig deep into the data and extract relevant information to translate research into the clinical realm effectively. That tangible resources are required to develop and implement standardized procedures.

In the last part of his talk, Dr. Rai discussed the use of EUS in guided gastroenterostomy (EUS-GE). Being the newest and most technically difficult of the three novel procedures described, we heard of the importance of collaboration in each stage of implementation. When Dr. Rai presented a study comparing conventional duodenal stenting with EUS-GE8, he highlighted the fact that there was no stent misdeployments, which is only achievable in the clinical realm with experience and training.

By encouraging more robust research to address Quality of Life outcomes, Dr. Rai created an important space for the patient perspective. In the conversation that followed the MGR, a tender moment transpired when a TMED student shared a personal story about EUS without anesthetic, and Dr. Rai validated her experience. Dr. Rai shared the growing application of EUS in a way that only someone with his unique expertise and experience could achieve. He left us all feeling like we can do better. With better access to relevant training materials and funding, potential to implement least invasive empirically supported EUS procedures is within reach.

References

1. Chen X, He H, Chen X, et al. A Bibliometric Analysis of Publications on Endoscopic Ultrasound. Frontiers Medicine. 2022;9. doi:10.3389/fmed.2022.869004

2. James PD, Hegagi M, Antonova L, et al. Regional differences in use of endoscopic ultrasonography in Ontario: a population-based retrospective cohort study. CMAJ Open. 2017;5(2): E437-E443. doi:10.9778/cmajo.20160153

3. Varadarajulu S, Bang JY, Sutton BS, Trevino JM, Christein JD, Wilcox CM. Equal Efficacy of Endoscopic and Surgical Cystogastrostomy for Pancreatic Pseudocyst Drainage in a Randomized Trial. Gastroenterology. 2013;145(3):583-590.e1. doi:10.1053/j.gastro.2013.05.046

4. van Santvoort HC, Besselink MG, Bakker OJ, et al. A Step-up Approach or Open Necrosectomy for Necrotizing Pancreatitis. New England Journal of Medicine. 2010;362(16):1491-1502. doi:10.1056/NEJMoa0908821

5. van Brunschot S, van Grinsven J, van Santvoort HC, et al. Endoscopic or surgical step-up approach for infected necrotising pancreatitis: a multicentre randomised trial. Lancet London England. 2018;391(10115):51-58. doi:10.1016/S0140-6736(17)32404-2

6. Teoh AYB, Kitano M, Itoi T, et al. Endosonography-guided gallbladder drainage versus percutaneous cholecystostomy in very high-risk surgical patients with acute cholecystitis: an international randomised multicentre controlled superiority trial (DRAC 1). Gut. 2020;69(6):1085-1091. doi:10.1136/gutjnl-2019-319996

7. Rana SS. Endoscopic ultrasound-guided gallbladder drainage: a technical review. Annals of Gastroenterology. 2021;34(2):142-148. doi:10.20524/aog.2020.0568

8. Teoh AYB, Lakhtakia S, Tarantino I, et al. Endoscopic ultrasonography-guided gastroenterostomy versus uncovered duodenal metal stenting for unresectable malignant gastric outlet obstruction (DRA-GOO): a multicentre randomised controlled trial. Lancet Gastroenterol Hepatol. 2024;9(2):124-132. doi:10.1016/S2468-1253(23)00242-X

Endoscopic Ultrasound: Potential and Limitations

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Endoscopic Ultrasound: Potential and Limitations

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