Endoscopic submucosal dissection of colon polyps with submucosal fibrosis using the combination of near-focus mode and traction device

Video

Video 1

Endoscopic submucosal dissection of colon polyps with submucosal fibrosis using the combination of near-focus mode and a traction device.

Lateral spreading tumor with the pseudo-depressed nongranular type (LST-NG-PD) of polyp has higher potential to contain malignancy and submucosal fibrosis than other subtypes.¹ Therefore, en bloc resection with endoscopic submucosal dissection (ESD) should be considered.² However, ESD of colorectal polyps with submucosal fibrosis is challenging, with high risk of perforation and incomplete resection.³ In this situation, the appropriate traction method, such as the clip-rubber-band method, could be helpful.^4,5 In addition, the near-focus mode of a dual-focus colonoscope enhances visualization of the submucosal plane because the typical dissection range is within the depth of field of near-focus mode (Fig. 1). Near-focus mode was reported to be helpful during the endoscopic submucosal tunneling procedure⁶; however, there is no report using this mode in facilitating colorectal ESD. Here, we present 2 cases of LST-NG-PD at the ascending colon that were challenging to resect because of submucosal fibrosis (Video 1, available online at www.videogie.org). This study was approved by the local institutional review board (no. 469/66), and consent for publication was obtained from the patients.

Figure 1.

The typical dissection range of endoscopic submucosal dissection is <10 mm. This range is compatible with depth of field of the near-focus mode of a dual-focus colonoscope, which is 4 to 9 mm for a 290 series colonoscope.

The first patient is a 62-year-old woman who presented with hematochezia. We performed a colonoscopy and found a 3.5-cm LST-NG-PD with type 0-IIa+IIc Paris classification at the ascending colon near the hepatic flexure (Fig. 2A). Magnifying narrow-band imaging (NBI) with near-focus mode showed a type 2B polyp of the Japanese NBI Expert Team (JNET) classification (Fig. 2B). Because of the risk of malignancy and submucosal fibrosis, we decided to perform ESD with a dual-focus colonoscope (CF-HQ290I; Olympus, Tokyo, Japan). The submucosal injection was performed with glycerol mixed with indigo carmine and adrenaline. We used a DualKnife (Olympus) to make the incision and dissect the submucosal layer. The submucosal dissection was difficult because of submucosal fibrosis; therefore, a self-made rubber band traction clip was applied (Fig. 3). During submucosal dissection, the near-focus mode improved the visualization of the submucosal plane and muscularis propria (Fig. 4). An insulated tip knife nano (Olympus) was used during the dissection of the fibrotic part. The tumor was successfully removed, and the mucosal defect was closed using endoscopic clips. The procedural time was 100 minutes. The patient was discharged on postoperative day 2 without adverse event, and the pathologic examination showed well-differentiated intramucosal adenocarcinoma with negative vertical and horizontal margins. There was no lymphovascular invasion or tumor budding.

Figure 2.

A, Endoscopic image showing a 3.5-cm lateral spreading tumor with type 0-IIa+IIc Paris classification at the ascending colon. B, Magnifying narrow-band imaging (NBI) with near-focus mode showed a type 2B polyp of the Japanese NBI Expert Team classification.

Figure 3.

A self-made rubber band traction clip was applied because of the difficult dissection of this lesion with submucosal fibrosis.

Figure 4.

Comparison of standard-focus and near-focus modes using a dual-focus colonoscope during endoscopic submucosal dissection. Near-focus mode enhances visualization of the submucosal plane and muscularis propria.

The second patient is a 60-year-old woman who underwent a screening colonoscopy. We found a 2.5-cm LST-NG-PD with type 2B JNET classification at the ascending colon. Because of submucosal fibrosis, the tumor was removed by ESD using near-focus mode and a traction clip similar to the first case (Fig. 5). The pathologic examination showed tubular adenoma with high-grade dysplasia and clear resection margins.

Figure 5.

The combination of near-focus mode and a self-made rubber band traction clip facilitates endoscopic submucosal dissection of a lateral spreading tumor with submucosal fibrosis.

The technique using near-focus mode during ESD can be used with other types of caps, such as the ST Hood (Fujifilm, Tokyo, Japan), because the dissection range is also within the depth of field of near-focus mode. The limitation of using a dual-focus colonoscope during ESD is limited endoscope maneuverability. A dual-focus colonoscope has 180° up-angulation range, which is less than a therapeutic pediatric colonoscope with 210° up-angulation range. This range facilitates lesion approachability, especially when dissection in the retroflexion position is required.

We present 2 cases of LST-NG-PD with submucosal fibrosis at the ascending colon using the combination of near-focus mode and a self-made rubber band traction clip. Combining these 2 methods improved the visualization of the submucosal plane, and we successfully removed the lesions without adverse event. The combination of near-focus mode and a traction device could be helpful during ESD of colon polyps with submucosal fibrosis because they enhance the visualization of the dissection plane.

Disclosure

The authors did not disclose any financial relationships.

Supplementary data

Video 1

Endoscopic submucosal dissection of colon polyps with submucosal fibrosis using the combination of near-focus mode and a traction device.