New methods
Experimental endoscopy
Simplified magnetic anchor-guided endoscopic submucosal dissection in dogs (with videos)

https://doi.org/10.1016/j.gie.2014.05.334Get rights and content

Background

Magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD) was developed to reduce adverse events such as bleeding and perforation and to facilitate ESD. However, the external electromagnet required miniaturization to make it suitable for daily clinical practice.

Objective

To evaluate the feasibility of simplified MAG-ESD using permanent magnets.

Design

Case series.

Setting

Nagoya University Hospital.

Subjects

Beagle dogs.

Interventions

The simplified MAG-ESD was performed on 10 representative areas of the stomachs of beagle dogs. The magnetic anchor consisted of an internal magnet attached to a hemoclip. The external and internal magnets were made from the rare earth neodymium.

Main Outcome Measurements

The feasibility of countertraction with good visualization using simplified MAG-ESD. The rate of perforation, the time required for preparation, and attaching the magnetic anchor were also evaluated.

Results

All lesions were successfully resected without perforation. The magnetic anchor could be controlled easily, and direct visualization was maintained by adequate counter traction. Preparing the magnetic anchor and grasping the mucosal edge using the hemoclip was easy and required a median of only 4 minutes (range, 2-7 minutes).

Limitations

Animal experiment, low number and lesion size.

Conclusions

This simplified MAG-ESD is feasible and allowed excellent visualization in the dog stomach. The feasibility of this system should be assessed in humans.

Section snippets

Test subjects

This study was approved by the Institute for Laboratory Animal Research at the Nagoya University Graduate School of Medicine in Japan (no. 25267), and was conducted in compliance with the laws for the humane treatment and management of animals. Two female beagle dogs (17 and 18 kg) were laid in the left lateral position on an examination table under intravenous anesthesia using propofol and pentazocine in intubated animals. Ten different representative areas were predetermined with coagulation

Results

Simplified MAG-ESDs using neodymium magnets were successfully performed in all cases without perforation (Fig. 2; Table 2; Videos 1 and 2, available online at www.giejournal.org). Adequate countertraction with good visualization was obtained using the external magnet.

In 8 cases, direct visualization was facilitated by an external magnet (magnetic attraction force, 382.9 N; magnetic flux density, 398 mT) (Fig. 1A, Table 1). However, in 2 cases, adequate countertraction could not be applied in

Discussion

Simplified MAG-ESDs using neodymium magnets were successfully performed in various representative areas of the beagle dog stomach. The magnetic anchor could be controlled, and adequate countertraction was obtained using the external magnet. In the case of a location at the posterior wall of the gastric angle, an additional magnetic anchor was necessary to facilitate good visualization for submucosal dissection. This may be caused by the distance between the external and internal magnets.

Several

References (22)

  • H. Imaeda et al.

    A new technique for endoscopic submucosal dissection for early gastric cancer using an external grasping forceps

    Endoscopy

    (2006)
  • Cited by (0)

    DISCLOSURE: All authors disclosed no financial relationships relevant to this publication.

    View full text