Initial experience with the prototype forward-viewing echoendoscope for therapeutic interventions other than pancreatic pseudocyst drainage (with videos)

Background The current oblique-viewing echoendoscope can occasionally be limited in its ability to perform therapeutic interventions because of the acute angle at which endoscopic accessories passed via the biopsy channel make contact with the gut wall. In an effort to overcome this limitation, a prototype forward-viewing echoendoscope was developed and successfully tested for performing transgastric drainage of pancreatic pseudocysts. Objective Evaluation of an initial experience with the prototype forward-viewing echoendoscope for performing interventions such as bile-duct drainage, pelvic-abscess drainage, and fiducial marker placement via the transduodenal and transrectal approaches. Design A retrospective study. Setting An academic tertiary-referral center. Patients Three patients. Interventions By using the prototype forward-viewing echoendoscope, transduodenal drainage of an obstructed bile duct, transrectal drainage of a pelvic abscess, and placement of fiducial markers in a rectal cancer were undertaken in 3 patients. Main Outcome Measurements To evaluate the feasibility of performing interventions via the transduodenal and transrectal approaches by using the prototype forward-viewing echoendoscope. Observations The procedures were technically successful in all 3 patients, and no procedural complications were encountered. The passage of accessories and the deployment of stents were technically easy with the forward-viewing echoendoscope. In addition, there was no need to reorient the position of the echoendoscope when switching from a sonographic to endoscopic view while performing therapeutic interventions. Limitation Small number of patients. Conclusions It was feasible to perform interventions such as drainage of an obstructive bile duct and a pelvic abscess, and placement of fiducial markers via the transduodenal and transrectal approaches by using the prototype forward-viewing echoendoscope. Further studies that include larger numbers of patients are needed to evaluate the role of the forward-viewing echoendoscope for performing EUS-guided therapeutic interventions.