A pilot proof-of-concept study of a modified device for one-step endoscopic ultrasound-guided biliary drainage in a new experimental biliary dilatation animal model

Abstract

Aim: To evaluate the technical feasibility of a modified tapered metal tip and low profile introducer for one-step endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD) in a new experimental biliary dilatation porcine model.

Methods: A novel dedicated device for one-step EUS-guided biliary drainage system (DEUS) introducer has size 3F tapered catheter with size 4F metal tip for simple puncture of the intestinal wall and liver parenchyma without graded dilation. A self-expandable metal stent, consisting of both uncovered and nitinol-covered portions, was preloaded into DEUS introducer. After establishment of a biliary dilatation model using endoscopic hemoclips or band ligation with argon plasma coagulation in 9 mini-pigs, EUS-BD using a DEUS was performed following 19-G needle puncture without the use of fistula dilation devices.

Results: One-step EUS-BD was technically successful in seven pigs [7/9 (77.8%) as intention to treat] without the aid of devices for fistula dilation from the high body of stomach or far distal esophagus to the intrahepatic (n = 2) or common hepatic (n = 5) duct. Primary technical failure occurred in two cases that did not show adequate biliary dilatation. In seven pigs with a successful bile duct dilatation, the technical success rate was 100% (7/7 as per protocol). Median procedure time from confirmation of the dilated bile duct to successful placement of a metallic stent was 10 min (IQR; 8.9-18.1). There were no immediate procedure-related complications.

Conclusion: Modified tapered metal tip and low profile introducer may be technically feasible for one-step EUS-BD in experimental porcine model.

Keywords: Biliary dilation; Biliary drainage; Complications; Endoscopic ultrasound; Feasibility.

Figure 1

Experimental biliary dilatation model using endoclips and endoscopic band ligation with argon plasma coagulation. A, B: Argon plasma coagulation (APC) was performed on the orifice of ampulla on the duodenal bulb following multiple rounds of hemoclipping on the ampulla of Vater; C, D: In an alternate model, endoscopic band ligation was performed on the ampulla of Vater, again followed by APC in the same manner.

Figure 2

Flow of experimental endoscopic biliary dilatation using clip closure and/or endoscopic band ligation with argon plasma coagulation in a porcine model. APC: Argon plasma coagulation; EBL: Endoscopic band ligation; IHD: Intrahepatic bile duct; CBD: Common bile duct; EUS-HE: Endoscopic ultrasound-guided hepaticoenterostomy.

Figure 3

Gross finding of dedicated device for one-step endoscopic ultrasound-guided biliary drainage system. A: The 7F delivery sheath and 3F catheter with 4F tapered pentagonal metal tip; B: Gross finding of the metallic stent. The uncovered proximal end of the stent (8 mm in diameter and 15 mm in length), the body and distal portions of the covered stent with a silicone membrane (6 mm in diameter and 35 or 45 mm in length), and the distal end with four flaps.

Figure 4

Endoscopic ultrasound-guided hepaticoenterostomy. A: Linear endoscopic ultrasound (EUS) image shows a 19-G needle puncture targeting the intrahepatic bile duct (IHD; B: Fluoroscopic image reveals marked IHD and common bile duct dilatation with ampullary obstruction; C: After EUS-guided 19-G needle puncture of the IHD, the device for one-step endoscopic ultrasound-guided biliary drainage system was inserted and the stent released under the guidance of EUS and fluoroscopy; D: Following successful deployment of the stent, the bile passage was seen in the high body of stomach.

Figure 5

Gross and microscopic findings in the autopsy specimens. A: Gross hepaticoenterostomy specimens showed that stent insertion along the far distal esophagus to the intrahepatic bile duct (IHD) via the liver parenchyma did not cause complications, such as stent dislocation or migration; B-D: Microscopic findings showed the distal esophagus (B), liver parenchyma (C), and IHD (D) sections adjacent to the inserted metallic stent. Surrounding mild inflammation and necrotic tissue were seen but without any other complications, such as abscess or perforation.