Technical Review of Developments in Endoscopic Ultrasound-Guided Hepaticogastrostomy

Abstract

Endoscopic ultrasound-guided biliary drainage has been developed as an alternative method for biliary drainage. EUS-guided hepaticogastrostomy (EUS-HGS) can be attempted via the trans-gastric route. These procedures are technically complex for two reasons. First, puncture of the intrahepatic bile duct via the trans-gastric route can be more difficult than that by other approaches because of the small diameter of the target site, and guidewire insertion or manipulation is challenging during EUS-HGS. Second, critical adverse events, such as stent migration into the abdominal cavity, could occur because of the greater mobility of the stomach compared to the duodenum. Therefore, endoscopists should be cautious when performing EUS-HGS. An advantage of EUS-HGS is that it can be performed in patients with complications such as duodenal bulb obstruction or surgically altered anatomy. Recent advances in technique and improvements in devices and stents for EUS-HGS have shown promise for improving the technical success rate of EUS-HGS and reducing the rate of adverse events. However, endoscopists should remain aware of the possibility of critical adverse events such as stent migration.

Keywords: Bile duct; Endoscopic retrograde cholangiopancreatography; Endoscopic ultrasound, Endoscopic ultrasound-guided hepaticogastrostomy.

Fig. 1.

Relationship between echoendoscope angle and needle. (A) When the angle between the echoendoscope and the needle is wide, guidewire insertion into the hepatic hilum may be challenging (arrow). (B) Guidewire insertion may be easier (arrow) when the angle between the echoendoscope and the needle is narrow.

Fig. 2.

Devices suitable for use in endoscopic ultrasound-guided hepaticogastrostomy with a 22 G needle. (A) A novel 0.018-inch guidewire (Fielder; Olympus Medical, Japan). (B) Ultra-tapered mechanical dilator (ES dilator; Zeon Medical, Tokyo, Japan). (C) Fine-gauge balloon catheter (REN biliary balloon catheter; KANEKA, Osaka, Japan). (D) Fine-gauge electrocautery dilator (Fine025; Medicos HIRATA, Osaka, Japan).

Fig. 3.

Steps during endoscopic ultrasound-guided hepaticogastrostomy using a 22 G needle. (A) The intrahepatic bile duct is slightly dilated (1.8 mm). (B) The intrahepatic bile duct is punctured using a 22 G needle. (C) A 0.018-inch guidewire is inserted. (D) Fistula dilation is performed using an ultra-tapered mechanical dilator. (E) A fully covered metal stent is deployed.

Fig. 4.

Loop-shape guidewire insertion. (A) The intrahepatic bile duct is punctured using a 19 G needle. (B) A 0.025-inch guidewire is inserted into the biliary tract but is complicated by penetration of the bile duct. (C) A novel 0.025-inch guidewire is inserted using the loop technique. (D) A plastic stent is deployed from the intrahepatic bile duct to the stomach.

Fig. 5.

Technical tips for the intra-scope channel release technique. (A) After the stent delivery system is inserted into the intrahepatic bile duct, the echoendoscope can be expelled from the hepatic parenchyma because of the pushing force of the stent delivery system (arrow). (B) When the stent delivery system is slightly withdrawn (arrow), adhesion is maintained between the hepatic parenchyma and the echoendoscope. (C) Stent release is then performed from the intrahepatic bile duct to the echoendoscope. Finally, the echoendoscope is gradually withdrawn while the stent delivery system is pushed.

Fig. 6.

Endoscopic Ultrasound-Guided Hepaticogastrostomy Using Novel Stent. (A) A novel partially covered metal stent (Spring Stopper; Taewoong Medical, Gimpo, Korea), which is a lumen-apposing stent that also prevents stent migration. The length of the proximal uncovered site is 1.5–2 cm to prevent stent dislocation and side branch obstruction. (B) Endoscopic appearance of the stent during endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS). (C) Computed tomography image of the stent during EUS-HGS.