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Deep mural injury and perforation after colonic endoscopic mucosal resection: a new classification and analysis of
Nicholas G Burgess1,2, Milan S Bassan1, Duncan McLeod3
1Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia.
Objectives:
Perforation is the most serious complication associated with endoscopic mucosal resection (EMR). We propose a new classification for the appearance and integrity of the muscularis propria (MP) after EMR including various extents of deep mural injury (DMI). Risk factors for these injuries were analysed.
Design:
Endoscopic images and histological specimens of consecutive patients undergoing EMR of colonic laterally spreading lesions ≥20 mm at a large Australian tertiary referral endoscopy unit were retrospectively analysed using our new DMI classification system. DMI was graded according to MP injury (I/II intact MP without/with fibrosis, III target sign, IV/V obvious transmural perforation without/with contamination). Histological specimens were examined for included MP and patient outcomes were recorded. All type III-V DMI signs were clipped if possible, types I and II DMI were clipped at the endoscopists' discretion.
Results:
EMR was performed in 911 lesions (mean size 37 mm) in 802 patients (male sex 51.4%, mean age 67 years). DMI signs were identified in 83 patients (10.3%). Type III-V DMI was identified in 24 patients (3.0%); clipping was successfully performed in all patients. A clinically significant perforation occurred in two patients (0.2%). Only one of the 59 type I/II cases experienced a delayed perforation. 85.5% of patients with DMI were discharged on the same day, all without sequelae. On multivariable analysis, type III-V DMI was associated with transverse colon location (OR 3.55, p=0.028), en bloc resection (OR 3.84, p=0.005) and high-grade dysplasia or submucosal invasive cancer (OR 2.97, p 0.014).
Conclusions:
In this retrospective analysis, use of the new classification and management with clips appeared to be a safe approach. Advanced DMI types (III-V) occurred in 3.0% of patients and were associated with identifiable risk factors. Further prospective clinical studies should use this new classification.
Trial Registration Number:
NCT01368289; results.
Insights
A new classification system for deep mural injury (DMI) after endoscopic mucosal resection (EMR) helps identify risk factors for perforation. This classification and clip management approach proved safe, with advanced DMI occurring in 3.0% of patients.
Area of Science:
- Gastroenterology
- Endoscopic Surgery
- Pathology
Background:
- Perforation is a serious complication of endoscopic mucosal resection (EMR).
- Assessing deep mural injury (DMI) integrity is crucial for patient outcomes.
- Existing classifications may not fully capture the spectrum of muscularis propria (MP) injury post-EMR.
Purpose of the Study:
- To introduce and validate a novel classification system for deep mural injury (DMI) appearance and muscularis propria (MP) integrity following EMR.
- To analyze risk factors associated with DMI after colorectal EMR.
- To evaluate the safety and efficacy of clip management for DMI.
Main Methods:
- Retrospective analysis of endoscopic images and histological specimens from patients undergoing EMR for colonic laterally spreading lesions ≥20 mm.
- Application of a new DMI classification system grading MP injury from I (intact) to V (transmural perforation with contamination).
- Correlation of DMI grades with patient demographics, procedure details, and clinical outcomes, including clip application.
Main Results:
- Deep mural injury (DMI) was identified in 10.3% of 911 EMR procedures (802 patients).
- Advanced DMI (Type III-V) occurred in 3.0% of patients, with successful clipping in all cases; clinically significant perforation occurred in 0.2%.
- Multivariable analysis linked Type III-V DMI to transverse colon location, en bloc resection, and high-grade dysplasia or submucosal invasive cancer.
Conclusions:
- The proposed DMI classification system and clip-based management appear safe and effective for EMR complications.
- Identifiable risk factors are associated with advanced DMI (Types III-V).
- Further prospective studies are recommended to validate this new classification in clinical practice.
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