Comments

In the present study, we demonstrated a high technical success rate (90%) for EPASS. Notably, in cases of the free style technique, the technical success rate was 9/9 (100%). These data are similar to or better than those of endoscopic stenting reported previously.4 In the EPASS technique, we considered several important points for a safe and reliable procedure as follows. First, we used a 0.89-inch large diameter guidewire and/or an overtube to facilitate passage of the double-balloon enteric tube into the jejunum beyond the ligament of Treitz even with the presence of severe obstruction. The importance of using a large diameter guidewire and/or an overtube is to avoid the looping of the balloon tube in the stomach fornix and enable its advancement over the 0.025-inch guidewire. In fact, in this study, the double-balloon tube could be advanced into the jejunum in all cases in approximately 10 min without any difficulty. In our experience, the overtube was superior to the guidewire for the balloon tube advancement. Second, anatomically the jejunum beyond the ligament of Trize is the most close position to the gastric wall based on our examination of a lot of screening upper GI graphy (unpublished data). Thus, if the saline solution is filled only between two balloons across this portion, the distended jejunum is easily located under EUS guidance, allowing easy and safe access to the jejunum. Third, we found that the cautery tipped delivery system (Hot Axios, Xlumena, Mountain View, California, USA) enables a true ‘one-step stenting’ for EUS-GJ, simplifying the procedure tremendously. In general, tract dilation is required in all EUS-guided transmural stent placement procedures and is eliminated if this delivery system is used. Eventually, EPASS was completely performed in the endoscopic unit within 30 min in all cases. Our present data suggest that EPASS is easier and faster than surgical GJ and is relatively comparable to endoscopic stenting.

Although direct access under EUS guidance appears simple, the ordinary jejunum is usually collapsed and can contain air, guaranteeing no safe puncture. Moreover, even if the puncture is successfully performed, following several steps such as guidewire advancement in the deeper jejunum, tract dilation and stent delivery system insertion is not easy because the collapsed jejunum can move away from the stomach. Thus, to date, there have only been two major techniques for EUS-GJ, namely, water-filling technique2 ,5 and water-inflated balloon technique.5 For the water-inflated balloon technique, although needle puncture to the inflated balloon (approximately 2 cm) appears easy to perform in the jejunum, following the procedure, however, seems to be difficult unless lumen-apposing devices such as a tilt-tag or an anchor wire are used ideally for securing the jejunum to the stomach wall and bringing together the two non-adherent organs. In terms of the water-filling technique, rapid infusion of a large amount of water to sufficiently dilate the small bowel may cause serious complications, including dilutional hyponatraemia and a general burden on the cardiovascular system. In addition, the injection of a large amount of fluid distends the targeted small intestine and the colon, leading to miss-puncture such as in gastrocolonostomy. Therefore, EPASS appears to be the preferred technique for EUS-GJ.

In the present study, we encountered two unsuccessful stent deployment cases. After carefully reviewing the video from the two failed cases, we realised that pushing the guidewire caused the distended jejunum to move away from the stomach, resulting in maldeployment of the LAMS. Since then, we stopped using the over-the-wire technique and selected the ‘free style’ direct catheter advancement/stent placement technique instead. Consequently, the technical success rate improved from 81.8% to 100%. Our result suggests that the best EUS-GJ technique is double-balloon tube placement using the overtube and the direct catheter advancement/stent placement using an electrocautery tipped delivery system containing a LAMS.

The main purpose of the therapy for MGOO is to restore the ability to eat. Thus, long-term stent function is one of the most important issues for the treatment of MGOO. Our results revealed that post-GOOSS score was significantly improved compared with pre-GOOSS score. In particular, a GOOSS score of 3 was observed in all cases but 1. Surprisingly, there were no stent occlusion cases needing re-intervention during the follow-up period. These results were quite different from previous data of endoscopic stenting and even surgical GJ.4 Our results suggest that a 15 mm diameter and 10 mm long stent works well for the intake of a low-residue or full diet. We are not sure whether a 15 mm diameter LAMS is ideal or not for MGOO treatment because the standard diameters of surgical GJ and endoscopic metal stents are 30 and 20 mm, respectively. However, a LAMS diameter of 15 mm was the maximum stent size that could be included in the 10.8-F delivery system. Nevertheless, we believe that a 15 mm fully covered LAMS can prevent tumour ingrowth and maintain sufficient stent patency based on the present results.

In terms of adverse events, stent maldeployment was observed in two cases (10%). As we observed this immediately after stent placement, the stent was removed and the patient was treated by conservative therapy. However, if the patient's condition is poor owing to cancer progression and concomitant acute cholangitis, stent maldeployment may cause a fatal event. Regarding the rate of late adverse events, such as stent occlusion due to tumour ingrowth or stent migration in EPASS using a LAMS, appears to be low compared with endoscopic stenting because of the biflanged, fully covered and short-length LAMS. From this point, once a LAMS is placed correctly, the long-term efficacy of EPASS appears to be similar to that of surgical GJ.

In conclusion, we established the feasibility of an EUS-GJ technique using a unique double-balloon tube and a novel electrocautery tipped stent delivery system equipped with a LAMS in the human setting.