C. Jonathan D. Foster, DO, Board Certified Gastroenterologist, Mercyhealth
Advanced therapeutic endoscopy is quickly emerging as the new frontier of gastroenterology. These procedures include endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS), endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD), and enteral stenting. Of these techniques, EUS has expanded into a field of therapeutic procedures.
The future of interventional endoscopic ultrasound is very exciting and challenging. As the field is rapidly growing, interventional EUS may shift future treatment modalities. EUS guided biliary and pancreatic drainage, treatment of neoplasia, creations of anastomosis, and treatment of bleeding are the areas we are seeing the most advancement.
"There is a bright future ahead for EUS in the years to come as more research is being done, tools are being developed, and interest in the field amongst endoscopist is increasing"
With these new procedures, it has allowed endoscopist to decrease amount of radiation exposure, shorten length of procedure times, and prevent more invasive surgical techniques. Creating anastomosis using an EDGE (EUS Directed transgastric ERCP) procedure for patients for altered anatomy in need of an ERCP has prevented patients from needing a laparoscopic surgery for the same procedure. EUS creates a fistula between the pouch and the gastric remnant and that allows us to perform endoscopy. This is just one example of the ever expanding endoscopic technologic advances.
Within the field of interventional EUS, not only have the echoendoscopes use to perform the procedure advanced, but the tools to perform the procedures have been advancing. There is new considerations for forwarding viewing (FV) echoendoscopes as compared to the current curvilinear array echoendoscopes (CLA). The FV-EUS scopes will allow easier access into difficult locations in the GI tract. Placement of fiducial markers, small metal objects, helps facilitate radiation treatment in pancreatic cancer. Treatment of pancreatic cysts and pancreatic neuroendocrine tumors can be completed by EUS guided radiofrequency ablation (RFA). A monopolar catheter can be used to cauterize and coagulate tissue. Further large scale studies are still needed in this area of treatment.
Even with all these new advancements, there is even more research being done. These include elastography and Needle-based confocal laser endomicroscopy (n-CLE). The underlying principle of elastography is that compression of a target tissue by a probe produces a smaller strain in hard (usually malignant) tissue than in soft (usually benign) tissue. A strain ratio is calculated and helps determine between benign and malignant lesions. N-CLE allows for in-vivo optical histology, and may serve as a second opinion to biopsy of pancreatic cysts in the future. Further advancements include injection local treatment of unresectable pancreatic malignancy.
Local injections of chemotherapeutic agents, such as gemcitabine, and cytoimplants have been performed.
The field of interventional endoscopy is rapidly changing and ever growing. Gastroenterologist are pushing the field to new levels. As expertise grows, interventional EUS appears to have the ability to replaces traditional surgical procedures. Its greatest ability is that it has allowed us to complete safe and accurate sampling of tissue. There is a bright future ahead for EUS in the years to come as more research is being done, tools are being developed, and interest in the field amongst endoscopist is increasing.