Intramural endoscopic surgery

AKA 'third-space endoscopy'

Procedures

1. POEM
2. Peroral pyloromyotomy for gastroparesis (gastric-POEM)
3. Submucosal tunnelling endoscopic resection of subepithelial tumours (STER)
4. Flexible endoscopic diverticulotomy for Zenker (FED)
5. Peroral endoscopic tunneling for restoration of the oesophagus (POETRE)

Basic principles

• Use of the submucosal plane, which is the plane between mucosa and muscularis propria, comprised of loose areolar tissue
• GA is highly preferable
• Abx should include antifungals
• Diagnostic endoscopy is performed

Procedure

• Initial submucosal bleb injection with mucosal flap incision - make sure it's of appropriate distance from the planned myotomy site - you want a bit of distance to allow this submucosal tunnel to act as a flap/valve if you perforate distally at the myotomy site
  • Can use a mixture incorporating methylene blue, adrenaline and saline to raise the bled (the dye helps to identify the submucosa)
  • If you don't see a weal developing, you're probably too deep, and need to draw back
• Creation of submucosal tunnel - use short bursts of electrocautery - may need repeated injections of submucosal fluid
• Myotomy/lesion excision
• Mucosal flap closure - easiest with haemostatic clips

Post-procedure

• Baseline erect CXR
• Get another CXR if patient deteriorates clinically
• Upper GI contrast study on day 1 - looking for leak or obstruction
  • If no major issues, start on liquid diet
• Most patients stay 24 hours or so
• Liquid diet 1-2 weeks
• PPI +/- sucralfate to prevent ulceration at myotomy