Endoscopic full-thickness resection of a lateral spreading rectal tumor after unplanned injection of dilute hyaluronic acid into the subserosal layer (with video)

Sclerotherapy needle injections can expand the subserosal and muscularis propria layers and cause a stable mucosal lift in ESD/EMR patients

Background

A mucosal lift is needed for ESD and EMR. Most lifts are made via sclerotherapy needle injection. The firm push needed to penetrate the mucosa often leaves the needle tip in the deep wall. The needle is next withdrawn and fluid injected until a sharp lift (due to submucosal expansion) begins to form; the needle is then held steady and the injection finished. The initial injection may result in a subtle deep lift that resolves quickly. It was the authors’ belief that only submucosal expansion could lead to a stable mucosal lift. A colonic ESD case in which a polyp was inadvertently resected via needle knife in an expanded subserosal plane led to a questioning of this position. This study’s purpose was to determine if stable deep wall mucosal lifts can be generated via bowel wall injection.

Methods

Transmucosal and intramural injections into bovine large bowel were carried out. Stable lifts and lift cross sections were made and examined grossly and histologically to determine the location of the lift fluid. Clinical ESD videos were also reviewed.

Results

Over 200 intact and cross-sectioned lifts were assessed. Gross inspection revealed two types of lifts (superficial and deep), whereas cross sections and histologic analyses revealed examples of stable expansion of the submucosal, muscularis propria, and subserosal layers post injection. Clinical “deep” lifts were also found. Superficial lifts are more focal and taller, whereas deep wall lifts are broader and less prominent.

Conclusion

Stable deep wall mucosal lifts occur and are likely due to the deep starting point of the needle post insertion. If ESD/EMR are attempted with a deep lift, the chances of failure or perforation are high. Lifts must be carefully scrutinized before starting ESD/EMR. Other means of lift establishment should be evaluated and considered.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6521-5) contains supplementary material, which is available to authorized users.

Unexpected endoscopic full-thickness resection of a duodenal neuroendocrine tumor

A 57-year-old man underwent endoscopy for investigation of a duodenal polyp. Endoscopy revealed a hemispheric submucosal tumor, about 5 mm in diameter, in the anterior wall of the duodenal bulb. Endoscopic biopsy disclosed a neuroendocrine tumor histologically, therefore endoscopic mucosal resection was conducted. The tumor was effectively and evenly elevated after injection of a mixture of 0.2% hyaluronic acid and glycerol at a ratio of 1:1 into the submucosal layer. A small amount of indigo-carmine dye was also added for coloration of injection fluid. The lesion was completely resected en bloc with a snare after submucosal fluid injection. Immediately, muscle-fiber-like tissues were identified in the marginal area of the resected defect above the blue-colored layer, which suggested perforation. The defect was completely closed with a total of 9 endoclips, and no symptoms associated with peritonitis appeared thereafter. Histologically, the horizontal and vertical margins of the resected specimen were free of tumor and muscularis propria was also seen in the resected specimen. Generally, endoscopic mucosal resection is considered to be theoretically successful if the mucosal defect is colored blue. The blue layer in this case, however, had been created by unplanned injection into the subserosal rather than the submucosal layer.