EUS-guided Balloon-occluded Gastrojejunostomy Bypass (EPASS) Versus Uncovered Duodenal Stent for Unresectable Malignant Gastric Outlet Obstruction.

In recent years, SEMSs have provided an attractive alternative to surgery for palliation of malignant gastric outlet obstruction. Several studies have assessed the clinical and technical success rates of pyloro-duodenal SEMS for malignant gastroduodenal obstruction. Technical success rates of 90% to 100% and clinical success of 80% to 95% was achieved.The procedure was associated with quicker recovery and reduced morbidities as compared to surgical gastrojeunostomies. However, the long-term patency of uncovered SEMS is limited by the risk of tumor ingrowth that would lead to subsequent re-stenosis of the stents requiring re-intervention. Thus to palliate malignant gastric outlet obstruction, surgical gastrojejunostomy is preferred in patients that are at good risk for surgery with prolonged life expectancy whilst insertion of pyloro-duodenal SEMS is preferred in patients that are associated with high-risk for surgery and short life expectancy.

In lieu of the above reasons, it would be the ideal situation if a gastrojejunostomy could be created endoscopically without surgery. The procedure could potentially avoid the risk of morbidities and mortalities associated with surgery whilst enjoying the superior patency associated with a gastrojejunostomy. However, a number of hurdles need to be overcome for safe creation of an anastomosis endoscopically. Firstly, the collapsed bowel (duodenum or jejunum) needs to be easily identified from the stomach. Secondly, a reliable method of creating an anastomosis needs to be available. Lastly, a device for maintaining the anastomosis between two non-adherent organs is required.

The use of EUS as a platform to create a gastrojejunostomy endoscopically may theoretically tackle all of the above hurdles. The device could be used in the stomach to visualize the adjacent duodenum or jejunum for anastomosis. A 19-gauge needle could be used to puncture the adjacent bowel for passage of a guide-wire to connect the two non-adherent organs. Thereafter, a SEMS could be placed between the two organs for creation and maintenance of the anastomosis.

Initial results of EUS-guided gastrojejunostomies from two studies have become available. Khashab et al reported EUS-GJ in 10 patients. Technical success was achieved in 9 patients (90%). Clinical success with resumption of solid oral intake was achieved in all 9 patients (100%), who underwent successful EUS-GE. 8 patients were able to tolerate almost a normal diet and/or full diet, and 1 patient tolerated a soft diet. There were no procedure-related adverse events. Mean procedure time was 96 minutes (range 45-152 minutes), and mean length of hospital stay was 2.2 days. In another multicenter study, 26 patients received EUS-GJ. Technical success was achieved in 24 patients (92 %). Clinical success was achieved in 22 patients (85 %). Of the 4 patients in whom clinical success was not achieved, 2 had persistent nausea and vomiting despite a patent EUS-GJ and required enteral feeding for nutrition, 1 died before the initiation of an oral diet, and 1 underwent surgery for suspected perforation. Adverse events, including peritonitis, bleeding, and surgery, occurred in 3 patients (11.5 %). In both of these studies, the AXIOS stent was used for creation of the anastomosis (Boston Scientific, Natick, MA, USA).

However, a common technical problem exists in both of these series. The target duodenum or jejunum needed for creation of a GJ is collapsed and it is difficult to identify the target organ by EUS from the stomach. Furthermore, the insertion of the stent for creation of the anastomosis may be difficult with a collapsed bowel and this may result in catastrophic outcomes. Our group has overcome this problem with a novel device - the double balloon occluder. The device comprises of two balloons that could occlude a segment of bowel. Saline could then be injected in to the occluded segment resulting in distension of the bowel and making it possible to be targeted by EUS from the stomach.