Original article
Clinical endoscopy
Prospective clinical trial of magnetic-anchor–guided endoscopic submucosal dissection for large early gastric cancer (with videos)

https://doi.org/10.1016/j.gie.2008.03.1127Get rights and content

Background

The treatment of early gastric cancer (EGC) by endoscopic submucosal dissection (ESD) has been rapidly gaining popularity in Japan. However, the procedure needs a high quality of skill. To facilitate complicated ESD by using a single working-channel gastroscope (“one-hand surgery method”), the magnetic-anchor-guided ESD (MAG-ESD) controlled by an extracorporeal electromagnet was reported to be successful in a porcine model.

Objectives

The purpose of this prospective clinical trial was to evaluate the feasibility of MAG-ESD for large EGC located on the gastric body in human beings.

Design

Prospective clinical trial at a single center.

Setting

National Cancer Center Hospital, Tokyo, Japan.

Subjects

From January 2005 to May 2006, 25 patients with EGC >20 mm in diameter, located in the gastric body, and intestinal-type histology were enrolled. Patients with a cardiac pacemaker, advanced malignancy in other organs, severe cardiac and/or pulmonary diseases, and uncontrolled hypertension and/or diabetes mellitus were excluded from this study.

Interventions

Similar to a standard ESD, the MAG-ESD procedure was performed with the patient under conscious sedation by intravenous injection of midazolam (3–5 mg) and pentazocine (15 mg).

Main Outcome Measurements

Unfavorable events and other intraoperative complications caused by the magnetic anchor or the magnetic force were recorded and evaluated. Two GI endoscopists (T.G., I.O.) assessed whether the magnetic anchor facilitated gastric ESD according to 2 criteria: “supportive” and “not supportive.” The en bloc resection rate, complications, total operation time, bleeding, perforation, and recurrence rate were also evaluated. The total operation time was measured from insertion to withdrawal of the endoscope, including the retrieving of the magnetic anchor or anchors.

Results

All tumors were resected en bloc, without any perforations or severe uncontrollable bleeding. All magnetic anchors were safely retrieved. Two endoscopists assessed that the MAG system was supportive in 23 patients. None of the patients experienced physiologic and mental abnormalities as a result of long-term magnetic-field exposure. During a median follow-up of 20 months (15–32 months), neither delayed adverse effects nor allergies caused by the stainless steel of the magnetic anchor were observed.

Conclusions

MAG-ESD is a feasible and safe method that allowed an excellent visualization by suitable tissue tension and facilitated gastric ESD in patients with EGC. The system should be miniaturized to make it applicable in daily clinical practice.

Section snippets

Patients

The purpose of this prospective clinical trial was to evaluate the feasibility of MAG-ESD. Twenty-five patients with EGC >20 mm diameter, located in the gastric body, were enrolled. The patients were first seen on an outpatient basis, and the tumor was assessed by a gastroscopy. From January 2005 to May 2006, all patients with EGC >20 mm in diameter, located in the gastric body, and with intestinal-type histology underwent an ESD on an inpatient basis at the National Cancer Center Hospital,

Results

The MAG-ESD technique was performed in 25 patients (M/F, 17/8; median age 70 years, range 48-85 years; median tumor size, 30 mm, range 20-70 mm).

The results of the MAG-ESDs are shown in Table 1. All tumors were resected en bloc, without any perforations or severe uncontrollable bleeding. The median size of resected specimen was 55 mm (33-125 mm). The median procedure time was 80 minutes (50-240 minutes). One resection was histologically confirmed as being noncurative because of deep submucosal

Discussion

The present study is, to our knowledge, the first clinical trial by using MAG-ESD for EGC in human beings. The feasibility of the technique for gastric cancer treatment was already evaluated in an animal study. The MAG-ESD technique permits excellent visualization of the submucosal layer, because it is possible to achieve suitable tissue tension. This simplifies a gastric ESD, even for large lesions located in the gastric body. The long-term exposure to the magnetic field did not cause any

Acknowledgments

We thank Professor Stefan Seewald (Department of Interdisciplinary Endoscopy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany) for his helpful suggestions for fluent medical English and encouragement with the preparation of the article.

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    DISCLOSURE: The authors report that there are no disclosures relevant to this publication. This study was supported by a grant-in-aid for the Research on Advanced Medical Technology of the Ministry of Health, Labor and Welfare, and a grant-in-aid for the Third Term Comprehensive 10-year Strategy for Cancer Control, of the Ministry of Health, Labor and Welfare, Japan.

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