Introduction

Severe submucosal fibrosis (SSF) in early gastric cancer (EGC) is known to cause technical difficulty for endoscopic resection.^{1, 2} Various methods have been reported to tackle this problem. However, there is no established consensus on the management of this situation. Endoscopic intermuscular dissection (EID) has been successfully used in the rectum to overcome SSF.³ The procedure involves the dissection between the circular and longitudinal layers of the muscularis propriae. Recently, the procedure has been used in the stomach for en bloc resection of a neuroendocrine tumor.⁴ We report a case endoscopic resection of early gastric cancer with severe submucosal fibrosis where EID was used to attain a negative vertical margin.

Aims & Methods

We aim to demonstrate the use of EID in the stomach to overcome the challenge of SSF in endoscopic resection of early cancer. An 81 year male underwent an upper endoscopy for heaviness and discomfort in the epigastrium for few months. It revealed an approximately 25mm lesion around a healed ulcer scar at the gastric angle on the lesser curvature side with irregular surface and vascular pattern and a clear demarcation line. Biopsy showed high grade dysplasia and endoscopic resection was planned. Since the lesion was over a healed ulcer scar, and endoscopy showed convergence of gastric folds towards the lesion, SSF was expected. The resection was started by conventional endoscopic submucosal dissection in retroflexion and a tunnel was created under the distal side of the tumor. However, after the incision and initial submucosal dissection, we encountered SSF. We decided to carefully dissect in the intermuscular plane underneath the fibrotic area by identifying and separating the circular and longitudinal muscle layer. Similar method was used on the oral side where EID was performed after initial ESD and tunnel was completed. Resection was accomplished and the circular muscle defect in the middle of the ulcer was closed with multiple endoclips.

Results

Total procedure time was 60 minutes. En bloc specimen measured 56mm x 40mm. There were no immediate or early complications. Patient was started on soft diet on post procedure day 1 and discharged on day 5. Pathology was tubular adenoma with high grade dysplasia. Horizontal and vertical margins were negative and specimen contained the muscle layer.

Conclusion

This case demonstrates the feasibility of EID in the stomach without any special accessories or equipment. EID can be used to overcome severe submucosal fibrosis in early gastric cancer. Further studies on wider applicability of gastric EID in clinical practice would be worthwhile.

References

1. Jeong JY, Oh YH, Yu YH et al. Does submucosal fibrosis affect the results of endoscopic submucosal dissection of early gastric tumors?. Gastrointestinal endoscopy. 2012 jul 1;76(1):59-66.
2. Higashimaya M, Oka S, Tanaka S et al. Outcome of endoscopic submucosal dissection for gastric neoplasm in relationship to endoscopic classification of submucosal fibrosis. Gastric Cancer. 2013 Jul;16:404-10.
3. Toyonaga T, Ohara Y, Baba S et al. Peranal endoscopic myectomy (PAEM) for rectal lesions with severe fibrosis and exhibiting the muscle-retracting sign. Endoscopy. 2018 aug;50(08):813-7.
4. Despott EJ, Lucaciu LA, Murino A et al. First report of gastric endoscopic intermuscular dissection. Endoscopy. 2024 Dec;56(S 01):E132-3.