In selected cases complete endoscopic removal of deep submucosal esophageal cancer is appropriate when surgery is not feasible. In order to achieve R0 resection the superficial circular muscle layer has to be dissected.

In non-surgical candidates, achieving R0 resection of deep submucosal esophageal cancer requires adequate prediction of how far the dissection must extend beyond the tumor. The problem is to determine the minimal depth that ensures complete tumor removal while still preventing perforation of the esophagus.

The innovative aspect of this case is the application of endoscopic muscularis dissection (EMD) in the esophagus, supported by a “tunnel first” evaluation approach. A submucosal tunnel was created to directly visualize the lesion in relation to the muscular layer. After  creating the tunnel, the invasion area became clearly identifiable, and dissection was extended along the right and left sides to determine both the depth and the longitudinal extent of involvement. This “tunnel first” approach added a safety advantage by allowing precise assessment of how deep and how long the infiltration extended, guiding a controlled proper dissection plane to keep the risk of perforation low. Dissection is performed with the TTJ Neo knife, followed by the ClutchCutter, which enables efficient dissection and hemostasis simultaneously.

A 45-year-old male with metastatic esophageal squamous cell carcinoma, under systemic therapy, presented with a newly detected early Barrett’s adenocarcinoma at the Z-line. Pre-procedural imaging and EUS suggested deep submucosal infiltration, but endoscopic resection was considered feasible as part of a palliative local-control strategy. The procedure began with creation of a submucosal tunnel to directly assess the tumor–muscularis infiltration. Within the tunnel, a clear muscular traction sign indicated superficial invasion into the muscle layer, prompting the decision to proceed with an endoscopic intramuscular dissection. The specimen was retrieved en bloc. A 4 × 3 cm R0 intramuscular resection was achieved without complications. Histopathology confirmed adenocarcinoma with sm2 invasion (1.1 mm), lymphatic invasion, and clear vertical and horizontal margins. No vascular or perineural invasion was present. At 6-month follow-up, endoscopy showed a completely healed, smooth scar with no residual or recurrent tumor. Biopsies were normal, and the patient remained under systemic treatment with stable local conditions.

This case illustrates that EMD, supported by a tunnel-first evaluation, enables assessment of invasion depth and effective intramuscular dissection in a palliative case. Even when deep submucosal involvement is predicted, EMD can provide complete local removal while preserving esophageal integrity. This approach may be considered for select patients in whom local control of the tumor is clinically significant