Retrievable puncture anchor traction method for endoscopic ultrasound-guided gastroenterostomy: A porcine study

Abstract

Background: Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is an alternative method for the surgical treatment of gastric outlet obstruction, but it is regarded as a challenging technique for endoscopists as the bowel is highly mobile and can tent away. Thus, the technique requires superb skill. In order to improve EUS-GE, we have developed a retrievable puncture anchor traction (RPAT) device for EUS-GE to address the issue of bowel tenting.

Aim: To evaluate the feasibility of RPAT-assisted EUS-GE using an animal model.

Methods: Six Bama mini pigs each weighing between 15 and 20 kg underwent the RPAT-assisted EUS-GE procedure. Care was taken to ensure that the animals experienced minimal pain and discomfort. Two days prior to the procedure the animals were limited to a liquid diet. No oral intake was allowed on the day before the procedure. A fully covered metal stent was placed between the stomach and the intestine using the RPAT-assisted EUS-GE method. Infection in the animals was determined. Four weeks after the procedure, a standard gastroscope was inserted into the pig's intestine through a previously created fistula in order to check the status of the stents under anesthesia. The pig was euthanized after examination.

Results: The RPAT-assisted EUS-GE method allowed placement of the stents with no complications in all six animals. All the pigs tolerated a regular diet within hours of the procedure. The animals were monitored for four weeks after the RPAT-assisted EUS-GE, during which time all of the animals exhibited normal eating behavior and no signs of infection were observed. Endoscopic imaging performed four weeks after the RPAT-assisted EUS-GE showed that the stents remained patent and stable in all the animals. No tissue overgrowth or ingrowth was observed in any case. Each animal had a mature fistula, and the stents were removed without significant bleeding. Autopsies of all six pigs revealed complete adhesion between the intestine and the stomach wall.

Conclusion: The RPAT method helps reduce mobility of the bowel. Therefore, the RPAT-assisted EUS-GE method is a minimally invasive treatment modality.

Keywords: Electrocautery-enhanced delivery of lumen-apposing metal stents; Endoscopic ultrasound; Endoscopic ultrasound-guided gastroenterostomy; Gastric outlet obstruction; Gastroenterostomy; Retrievable puncture anchor.

Figure 1

The retrievable puncture anchor. A: The retrievable puncture anchor (Vedkang Inc., Changzhou, Jiangsu, China) in its entirety; B: The head of the anchor; C and D: A view of the passage of the anchor along the shaft of the puncture needle.

Figure 2

The retrievable puncture anchor traction method. A: Schematic diagram: The bowel is punctured under endoscopic ultrasound (EUS) guidance; B: Endoscopic ultrasound image: The bowel is punctured under EUS guidance; C: Schematic diagram: The retrievable puncture anchor is passed through the needle; D: Endoscopic ultrasound image: The anchor is inserted into the bowel; E: Schematic diagram: After pulling out the needle, the anchor attaches to the bowel; F: Endoscopic ultrasound image: After pulling out the needle, the anchor attaches to the bowel; G: Schematic diagram: The identified small-bowel loop is punctured again under EUS guidance. A guidewire is inserted through the needle. The small bowel is shown being punctured and drained using electrocautery-enhanced delivery of lumen-apposing metal stents over the guidewire; H: Endoscopic ultrasound image: The anchor-grasped bowel is shown under traction for stent implantation; I: Schematic diagram: The retrieval cord is pulled using a pair of forceps; J: Endoscopy image: The retrieval cord is pulled using a pair of forceps; K: Schematic diagram: The retrievable puncture anchor is easily removed; L: Endoscopy image: The retrievable puncture anchor is easily removed.

Figure 3

Endoscopic imaging of stent placement and anastomoses. A and B: Endoscopic imaging shows the well-reflected proximal flange of the stent immediately after deployment in the initial session; C: The stents were still in the same position 4 wk later and no traumatic changes were observed; D: A standard gastroscope was easily advanced through the anastomosis to observe the afferent and efferent bowel loops.

Figure 4

Autopsy and histological findings. A-C: Necropsy and histological evidence shows complete adhesion between the bowel and the stomach wall (20 ×).