How do I place a self‑expanding metal duodenal stent endoscopically via a standard gastroscope in a patient with short‑segment malignant duodenal obstruction who is not a candidate for curative surgery?

Endoscopic Duodenal Stent Placement for Malignant Gastric Outlet Obstruction

For patients with short-segment malignant duodenal obstruction who are not surgical candidates, place a self-expanding metal stent (SEMS) endoscopically using a standard therapeutic gastroscope under combined endoscopic and fluoroscopic guidance, crossing the stricture with a guidewire and catheter before deploying the stent using an over-the-wire technique. 1, 2, 3

Patient Selection

Before proceeding with duodenal stenting, confirm the patient meets these criteria:

• Life expectancy < 2 months, poor functional status, or surgically unfit – these patients benefit most from SEMS rather than surgical gastrojejunostomy 1, 2
• Absence of multiple luminal obstructions or severely impaired gastric motility – these are contraindications to enteral stenting and warrant venting gastrostomy instead 1, 2
• Short-segment obstruction – longer stenosis length ≥ 4 cm predicts higher mortality (HR 1.92) 4

Technical Procedure

Equipment and Setup

• Use a front-facing therapeutic gastroscope (standard upper endoscope) 3
• Ensure combined endoscopic and fluoroscopic guidance throughout the procedure 3, 5, 6
• Select an uncovered or fully covered through-the-scope SEMS appropriate for duodenal deployment 7, 5

Step-by-Step Technique

1. Visualize the obstruction endoscopically and assess the stricture length and location (D1, D2, D3, or D4) 3

2. Cross the stricture under direct vision and fluoroscopy using a catheter and guidewire 3

   • This step is technically challenging for obstructions distal to the duodenal bulb but achievable with careful technique 3

3. Deploy the SEMS using an over-the-wire technique 3

   • Position the stent to allow at least 2 cm margin both proximally and distally from the stricture 1
   • Technical success rates are 89-99% 7, 3, 6

4. Confirm proper stent expansion fluoroscopically before completing the procedure 5, 6

Expected Outcomes

Clinical Success

• Clinical success rates range from 73-92%, defined as improvement in oral intake and Gastric Outlet Obstruction Scoring System (GOOSS) scores 7, 5, 6, 8
• Patients typically improve from GOOSS score of 0.6-0.9 pre-procedure to 2.6-2.7 post-procedure 7, 3
• Most patients (92%) can resume oral diet, with 73% tolerating solid or soft food 6
• Earlier oral intake compared to surgery, though durability is shorter 1, 2

Stent Patency and Survival

• Median stent patency: 100-149 days 7, 5, 9
• Median survival after stent placement: 58-120 days 3, 5, 9
• Stent dysfunction occurs in 7.7-22% of patients, primarily from tumor ingrowth/overgrowth 7, 5, 9
• 93.3% of patients maintain gastric outlet obstruction control with duodenal stenting alone 9

Complications and Management

Adverse Events

• Overall complication rate: 6-30% 6, 9, 10
• Procedure-related complications in 10.3%: primarily mild pneumonitis 7
• Stent migration: 4% 6
• Duodenal perforation: rare (3%) but requires surgical management 6
• No procedure-related mortality in most series 7, 3

Managing Stent Dysfunction

• Tumor ingrowth/overgrowth is the primary cause of stent occlusion 7, 5
• Endoscopic re-intervention with second stent placement is successful in all cases 5, 9, 10
• Consider overlapping stents if initial stent is insufficient 6

Prognostic Factors

Factors Associated with Better Outcomes

• Post-stenting chemotherapy significantly improves survival (HR 0.33) 10, 4
• Glasgow Prognostic Score (GPS) 0-1 before stenting predicts prolonged survival 10
• Stricture location in D3 (distal to papilla) associated with better outcomes 10
• Low neutrophil-to-lymphocyte ratio predicts improved survival 9

Factors Associated with Worse Outcomes

• Pre-existing biliary stricture reduces stent patency 9
• Stent placement across the pylorus decreases patency 9
• Stenosis length ≥ 4 cm predicts higher mortality 4

Special Considerations

Concurrent Biliary Obstruction

• 25% of patients have previously placed biliary stents that remain patent during duodenal stenting 6
• Biliary stenting can be attempted during the same procedure in 18% of cases 6
• Monitor for biliary complications if stent crosses the papilla 10, 4

Alternative to Surgery

Duodenal stenting offers significant advantages over surgical gastrojejunostomy in appropriate patients:

• Minimally invasive with no procedure-related mortality 7, 3
• Shorter hospital stay (median 4 days post-procedure) 3
• Facilitates hospital discharge in 71% of patients 8
• Allows earlier resumption of chemotherapy 1, 2

However, surgical gastrojejunostomy provides better long-term durability and should be considered for patients with life expectancy > 2 months who are surgically fit 1, 2