How to perform Endoscopic Ultrasonography (EUS) on a patient with a gastric bypass?

Performing EUS in Patients with Gastric Bypass

For patients with gastric bypass anatomy, EUS-directed transgastric access using lumen-apposing metal stents (LAMS) is the recommended approach to access the excluded stomach and perform necessary interventions with a technical success rate of over 90%. 1, 2

Pre-Procedure Planning

• Obtain appropriate cross-sectional imaging (MRCP or CECT) prior to the procedure to:
  • Understand the altered surgical anatomy
  • Visualize potential access routes
  • Identify any complications requiring intervention 3
• Ensure multidisciplinary support is available (interventional radiologists, surgeons, anesthesiologists) 3
• Administer prophylactic antibiotics before the procedure to prevent infection 3

Technical Approaches for EUS in Gastric Bypass Patients

1. EUS-Directed Transgastric ERCP (EDGE) Technique

This is the preferred approach for Roux-en-Y gastric bypass patients:

• Use a linear echoendoscope to identify and access the excluded stomach from the gastric pouch or Roux limb
• Deploy a 19-gauge EUS-FNA needle to puncture into the excluded stomach 3
• Pass a 0.035-inch or 0.025-inch guidewire with a floppy tip through the needle 3
• Deploy a lumen-apposing metal stent (LAMS) over the wire to create a gastrogastric or jejunogastric fistula 2, 4
• The LAMS creates a stable conduit for subsequent endoscope passage
• Either perform ERCP during the same session or as a separate procedure after fistula maturation (typically 2-3 weeks) 1

2. EUS-Assisted Fluoroscopically Guided Gastrostomy

Alternative approach when EDGE is not feasible:

• Use EUS to puncture and insufflate the excluded stomach
• Place a percutaneous gastrostomy tube under fluoroscopic guidance 5
• This provides access for subsequent interventions

Advantages of EUS-Directed Approach vs. Enteroscopy

• Higher technical success rate (100% vs 60%) 4
• Significantly shorter procedure time (49.8 min vs 90.7 min) 4
• Shorter hospital stays (1 day vs 10.5 days) 4
• Similar safety profile (adverse event rates 10% vs 6.7%) 4

Potential Complications and Management

• LAMS dislodgment (monitor for and replace if needed) 2
• Abdominal pain (manage conservatively with analgesics) 1
• Infection (use prophylactic antibiotics) 3
• Weight regain (not commonly reported with temporary LAMS placement) 2

Technical Considerations

• For pancreatic duct access: use a 19-gauge needle and 0.035-inch or 0.025-inch guidewire with floppy tip 3
• For tract dilation: use catheters, balloons, or cystotomes (avoid precut papillotomes) 3
• For stenting: use plastic stents without intervening side holes for pancreatic procedures 3
• For biliary procedures: fully or partially covered metal stents are recommended for transluminal stenting 3

Training Requirements

• Procedures should be performed at expert centers with facilities and expertise in interventional EUS and advanced ERCP 3
• Endoscopists should be experienced in EUS-FNA, wire manipulation techniques, and stent placement 3
• ERCP skills are beneficial and should be incorporated into training 3

The EDGE technique has revolutionized access to the excluded stomach in gastric bypass patients, allowing for conventional ERCP and other interventions with high success rates and acceptable safety profiles.