What are the indications for Endoscopic Submucosal Dissection (ESD) in sessile polyps?

Indications for Endoscopic Submucosal Dissection (ESD) in Sessile Polyps

ESD is the Grade I recommendation for sessile colorectal polyps ≥20 mm with specific high-risk features including lateral spreading tumors, villous adenomas ≥25 mm, polyps with fibrosis, and T1 colon cancer with submucosal invasion <1 mm. 1, 2

Primary Grade I Indications (Strongest Recommendations)

For these lesions, ESD should be your first-line endoscopic approach:

• Lateral spreading tumors ≥20 mm – These lesions require en bloc resection to ensure complete pathologic assessment and minimize recurrence 1, 2
• Villous adenomas ≥25 mm – The size and histology make piecemeal resection inadequate 1, 2
• Sessile polyps with fibrosis – Prior biopsy, cautery, or tattoo-induced fibrosis prevents adequate lifting for conventional EMR 1, 2
• T1 colon cancer with submucosal invasion <1 mm – ESD allows precise histologic assessment of invasion depth, differentiation, lymphovascular invasion, and margin status 1, 2

Grade II Indications (Alternative to EMR)

Consider ESD as a strong alternative when:

• Flat lesions 5-20 mm – EMR remains Grade I, but ESD is appropriate if you suspect submucosal invasion or fibrosis is present 1, 2
• Sessile lesions >10 mm suspected to be villous adenomas or sessile serrated adenomas/polyps – EMR is Grade I, but ESD provides better en bloc resection rates 1, 2
• Mucosal or submucosal adenomas >20 mm – Piecemeal EMR (PEMR) is Grade I, but ESD is preferred when en bloc resection is critical for accurate staging 1, 2

Morphologic Features That Mandate ESD Consideration

The US Multi-Society Task Force identifies specific scenarios where ESD should replace conventional EMR:

• Large-sized lesions (>20 mm) where inject-and-cut EMR cannot achieve en bloc resection – Piecemeal EMR carries 15-20% recurrence rates versus 0.9-2% for ESD 2, 3, 4
• Lesions with suspected submucosal invasion – En bloc resection is essential for accurate pathologic staging 2, 3
• Local residual early carcinoma after prior endoscopic resection – Fibrosis from previous attempts makes EMR ineffective 2, 3
• Non-polypoid colorectal dysplasia in inflammatory bowel disease patients – These lesions require complete excision with clear margins 2, 3

Morphologic Risk Stratification Algorithm

Use this approach to identify high-risk sessile polyps requiring ESD:

Step 1: Assess Paris Classification and Surface Morphology

• LST-NG (non-granular laterally spreading tumors) with sessile shape or depression – These predict higher risk of submucosal invasion 1
• LST-G (granular) with a dominant nodule – At minimum, the nodular component requires en bloc resection 1
• Depressed (0-IIc) morphology – 61% of these lesions contain submucosal invasion even when small 1
• 0-Is or 0-IIa+0-Is morphology – Associated with 2.5-2.7 times increased odds of submucosal invasive cancer 1

Step 2: Evaluate Surface Features

• NICE 3 classification features (disrupted surface pattern, absent vessels, or dark brown color) – 94% accuracy for predicting deep submucosal invasion 1
• Kudo pit pattern type V or VN – 90.4% sensitivity and 88.4% specificity for invasive cancer 1
• Surface ulceration or irregularity – In LST-NG with depression, risk of deep invasion is 12.5% for 10-19 mm lesions, 32.4% for 20-29 mm, and 83.3% for ≥30 mm 1

Step 3: Test for Fibrosis

• Non-lifting sign after submucosal injection – Indicates fibrosis from prior manipulation or submucosal invasion; proceed with ESD rather than EMR 1

Critical Caveats and Pitfalls

Before proceeding with ESD, you must address these mandatory considerations:

Pre-Procedure Requirements

• All non-pedunculated polyps suspected of malignancy require definitive pathology confirmation before deciding on endoscopic resection – Biopsy the area of surface disruption and tattoo the lesion (not in or near cecum) 1, 2
• If NICE 3 or Kudo VN features are present, direct the patient to surgery rather than attempting ESD – These indicate deep submucosal invasion with high lymph node metastasis risk 1

Post-ESD Staging for T1 Cancer

• T1-stage cancer carries approximately 15% risk of regional lymph node metastasis, which endoscopic resection cannot assess 1, 2
• Mandatory post-ESD workup includes: local colonoscopy examination, CEA testing, abdominal ultrasound, and chest/abdominal CT scans 1, 2

Histologic Criteria for Curative ESD

ESD is considered curative ONLY when ALL of the following are met: 1, 2, 4

• Submucosal invasion <1 mm (or <1000 μm)
• Absence of lymphovascular invasion
• Well or moderately differentiated tumor
• No tumor budding (low-grade budding acceptable)
• Distance of tumor to margin ≥1 mm (negative resection margins)

If any criterion is not met, refer for surgical resection with regional lymph node dissection 1

Follow-Up Strategy

• If margin status is uncertain, perform endoscopic re-examination within 3-6 months 1
• If margins are negative, follow-up endoscopy within 1 year after ESD 1
• Recurrence after PEMR occurs in 15-20% of cases versus 0.9-2% after ESD – This justifies the technical complexity of ESD for large lesions 3, 4

Technical Considerations

ESD requires specific expertise and equipment:

• Pin the ESD specimen to a flat surface (cork board) and immerse in formalin – This allows accurate pathologic assessment of margins and invasion depth 3
• Expert GI pathologist evaluation is mandatory for margin involvement, differentiation, lymphovascular invasion, depth of submucosal invasion, and tumor budding 3
• Avoid tattooing in close proximity to or beneath a lesion – This induces submucosal fibrosis that hampers future EMR or ESD 3
• Prior attempted EMR increases odds of ESD failure 3.8-fold – The first resection attempt is the most important determinant of outcome 5