Combined use of endoscopic ultrasound and confocal endomicroscopy for complete EMR of early gastric neoplasia

Background:

Endoscopic mucosal resection (EMR) is an alternative to surgery for removal of superficial gastric neoplastic lesions.

Current methods of EMR require proficiency in determining the extent of the neoplastic lesions (lateral and deep), and residual neoplastic tissue of the resection interface was difficult to detect by conventional endoscopy.

EUS has been shown to provide the most accurate clinical staging information for depth of tumor invasion

Confocal laser endomicroscopy (CLE) is a novel technique that allows in vivo microscopic examination of the gastrointestinal mucosa. CLE enables the endoscopist to obtain real time “optical biopsies” during ongoing endoscopy.

The value of CLE in predicting completeness of EMR has not been explored.

Aim:

EUS To prospectively assess the efficacy of endoscopic ultrasound (EUS) and confocal endomicroscopy (CLE) assisted EMR for the treatment of superficial gastric neoplastic lesions.

Primary endpoints were tumor free vertical/horizontal resection margins and positive histopathologic diagnosis. Secondary endpoints were the diagnostic accuracy of EUS and CLE.

Methods:

Patients and EUS:

Patients with biopsy proven high-grade intraepithelial neoplasia and intramucosal carcinoma in superficial gastric lesions were initially staged with EUS.

In patients with disease limited to the mucosa on EUS (Figure 2), “inject and cut” or cap-assisted EMR was performed.

Histopathologic assessment:

An experienced pathologist, blinded to the endoscopic information, examined all specimens with special attention to depth of tumor invasion and the lateral margins of excision.

Patients with remnant tissue in vertical margin were defined as having treatment failure, and operable patients were scheduled for gastrectomy.

Assessment by CLE:

Before EMR, CLE was used to confirm suspicious areas. The outer boundary of the lesion was marked using the tip of a snare diathermy and EMR was then performed.

After EMR, resection margins were inspected again by using CLE and completeness of excision was predicted. Additional EMR were performed if necessary.

Results:

Efficacy of EUS:

EUS was performed in 21 consecutive patients, and submucosal invasion was diagnosed in 4 by EUS (confirmed in 3/4at surgery).

EMR was carried out in the remaining 17 patients with 17 lesions.

Efficacy of CLE evaluation:

All lesions were successfully identified by CLE.13 patients had HGIN and 3 patients had intramucosal carcinoma. One carcinoma (4.8%) was considered to have deep margins involved and confirmed submucosal adenocarcinoma in gastrectomy.

Two LGIN were found in lateral margins and one of the two lesions was detected by CLE post-evaluation. (Figure 4)

This residual lesion was treated by additional EMR guided by CLE.

Efficacy of combination:

Thus, the final rate of complete resection of EMR was 88.2% (15/17). Overall, EUS provided accurate staging in 19/21 patients (90.5%). Residual neoplasias after EMR could be predicted by CLE with an accuracy of 88.2%.

Conclusion:

Combined use of endoscopic ultrasound and confocal endomicroscopy is feasible to identify inconspicuous neoplasia and assist EMR of superficial gastric lesions.

CLE has a high accuracy for prediction of remnant tissue after EMR.

This combination may lead to significant improvements in the clinical outcomes of endoscopic resection.

Acknowledgements:

This study was funded by the program from clinical projects of ministry of Health of China (2007) and the Taishan Scholar Program of Shandong Province.