Short- and long-term outcomes of standardized EMR of nonpolypoid (flat and depressed) colorectal lesions ≥ 1 cm (with video)

Background: Nonpolypoid (flat and depressed) colorectal lesions are increasingly recognized. Their endoscopic removal requires specialized EMR techniques, which are more complex to perform. Outcomes data on EMR of nonpolypoid neoplasms in the United States is needed. Objective: To determine the safety and efficacy of EMR in the resection of nonpolypoid colorectal neoplasms >= 1 cm. Design: Retrospective analysis. Setting: Veterans Affairs Palo Alto Health Care System. Patients: Over a 5-year period, patients who underwent EMR for nonpolypoid colorectal lesions >= 1 cm. Intervention: A standardized approach that included lesion assessment, classification, inject-and-cut EMR technique, reassessment, and treatment of residual tissue. Main Outcome Measurements: Complete resection, bleeding, perforation, development of advanced cancer, and death. Results: A total of 100 patients (125 lesions: 117 flat and 8 depressed) met inclusion criteria. Mean size was 16.7 +/- 7 mm (range, 10-50 mm). Histology included 5 submucosal invasive cancers, 5 carcinomas in situ, and 91 adenomas. Thirty-eight patients (48 lesions) did not receive surveillance colonoscopy: 8 had surgery, 16 had hyperplastic pathology, and 14 did not undergo repeat examination. Surveillance colonoscopy was performed on 62 patients (77 lesions). Complete resection was achieved in 100% of these patients after 1 to 3 surveillance colonoscopies. All patients received follow-up (mean [standard deviation] = 4.5 +/- 1.4 years); none developed colorectal cancer or metastasis. Limitations: Single endoscopist, retrospective study. Conclusions: A standardized EMR (inject-and-cut) technique is a safe and curative treatment option in nonpolypoid colorectal neoplasms (>= 1 cm) in the United States.