Interventional Endoscopic Ultrasound

Abstract

Endoscopic ultrasonography (EUS), since its development in the 1980s, has undergone a great deal of technological advancement in imaging, scopes with larger channels and accessories. This has given the endosonographer an immense reach in terms of accessing difficult areas with fewer complications. Currently, it is possible not only to obtain tissue for histological diagnosis but also to perform therapeutic procedures that hitherto would have needed surgery with its attendant morbidity. EUS has evolved over the years and EUS-guided fine needle aspiration for histological diagnosis has become standard practice. A wide array of interventional procedures are performed under EUS guidance including, celiac plexus neurolysis, drainage of pancreatic and pelvic fluid collections, drainage of obstructive biliary/pancreatic ducts, and implantation of fiducial markers/radioactive seeds into gastrointestinal tumors. Also, various experimental procedures are underway evaluating the role of EUS in radiofrequency ablation, vascular therapy, and natural orifice transluminal endoscopic surgery. In this review, we examine the various EUS-guided interventions currently undertaken and explore the potential of other emerging experimental techniques.

Endoscopic Management of Pancreatic Cancer: From Diagnosis to Palliative Therapy

“…A similar technique involving the injection of triamcinolone is performed in patients with chronic pancreatitis for pain control. (Ramesh & Varadarajulu, 2008) Significant reduction of pain scores 12 weeks after CPN was observed in 30 patients with advanced intra-abdominal malignancy, while 91% of these patients required same or less pain medication and 88% of patients had persistent improvement in their pain score. (Wiersema et al, 1996) Similarly, in another study of 58 patients with unresectable pancreatic cancer, EUS-guided CPN lowered pain scores in 78% at 2 weeks and a sustained response was noted until 24 weeks.…”

“…Other complications include bleeding, pneumoperitoneum, infection caused by stent occlusion/migration, and death. (Ramesh & Varadarajulu, 2008;Irisawa et al 2009) Plastic stents are the most commonly used during this approach; however, transduodenal and transgastric placement of self-expandable metal stents (SEMS) for palliation of malignant biliary obstruction has been reported and some authors report antegrade placement achieving transpapillary or, in case of post-surgical anatomy, transanastomotic placement. (Siddiqui et al, 2011;Nguyen et al, 2010;Artifon et al, 2010) EUS-guided pancreatic duct drainage can also be accomplished.…”

“…(Ramesh & Varadarajulu, 2008;Puli et al, 2009;Kaufman et al, 2010) This procedure entails the injection of absolute alcohol under EUS guidance to destroy the sympathetic plexus near the celiac axis. A similar technique involving the injection of triamcinolone is performed in patients with chronic pancreatitis for pain control.…”

“…Although fiducials can spontaneously migrate from the initial injection site, the reported rate of migration is low (7%), and no migration-related complications have been documented. (Ramesh & Varadarajulu, 2008;Park et al, 2010;Sanders et al, 2010) The EUS-guided placement of fiducials has traditionally involved the use of 19 gauge needles. However, a recently published case series reported the feasibility of using a 22 gauge needle, which may permit greater access when compared to a 19 gauge needle technique.…”

“…(Sun et al, 2006) Small size studies have demonstrated the technical feasibility of EUS-guided implantation of radioactive seeds in pancreatic tumors, and the technique appears to be well tolerated. (Ramesh & Varadarajulu, 2008;Sun et al, 2006) However, larger studies evaluating this technique and its role in a multimodality approach in combination with chemotherapy and/ or external beam radiation are needed.…”