Are both circular and longitudinal muscle fibers respected in Heller's myotomy and Peroral Endoscopic Myotomy (POEM) for a patient with achalasia cardia?

Muscle Fiber Involvement in Heller Myotomy vs POEM

No, both circular and longitudinal muscle fibers are NOT respected in both procedures—Heller myotomy divides both circular and longitudinal muscle layers completely, while POEM selectively divides only the circular muscle layer, preserving the longitudinal fibers. 1, 2

Heller Myotomy Technique

Heller myotomy requires complete division of both muscle layers:

• The procedure divides both the circular and longitudinal muscle layers of the lower esophageal sphincter to relieve esophagogastric junction outflow obstruction 1
• Complete surgical isolation of the esophagogastric junction is mandatory, requiring division of the phrenoesophageal ligament and short gastric vessels 1, 2
• This extensive dissection disrupts critical anti-reflux mechanisms that maintain the angle of His, making concomitant fundoplication necessary 1, 2

POEM Technique

POEM selectively targets only the circular muscle layer:

• A circular muscle myotomy is performed from within the submucosal tunnel, beginning at least 2-3 cm distal to the mucosotomy 3, 2, 4
• The longitudinal outer esophageal muscular layer is intentionally preserved during standard POEM 5
• POEM avoids gastroesophageal junction dissection entirely, preserving the phrenoesophageal ligament and short gastric vessels 2

Clinical Implications of This Difference

The selective myotomy approach in POEM offers technical advantages but creates reflux concerns:

• Despite preserving the longitudinal layer and avoiding EGJ dissection, POEM paradoxically carries substantially higher reflux risk with GERD evidence in up to 58% of patients 2, 3
• Erosive esophagitis occurs in 23-48% of POEM patients compared to lower rates with Heller myotomy plus fundoplication 2, 3
• Meta-analysis demonstrates an odds ratio of 9.31 for erosive esophagitis with POEM compared to LHM 3, 2

One research study challenged the selective approach:

• A comparative study of 234 patients found that full-thickness myotomy (dividing both layers during POEM) significantly reduced procedure time without increasing adverse events or reflux complications 5
• Treatment success was comparable between full-thickness (96.0%) and circular-only (95.0%) myotomy approaches 5
• However, this contradicts the standard POEM technique described in guidelines, which specifically performs circular muscle myotomy only 3, 2, 4

Postoperative Management Differences

Both procedures require aggressive reflux management:

• Mandatory 8 weeks of proton pump inhibitor therapy after both procedures 2, 4
• Consider indefinite PPI therapy given high reflux rates (up to 58% after POEM, variable after Heller myotomy with fundoplication) 1, 2
• Post-POEM patients should be counseled about potential indefinite PPI therapy and surveillance endoscopy requirements before undergoing the procedure 3