Endoscopic submucosal dissection (ESD) for superficial non-ampullary duodenal epithelial tumors (SNADETs) has been reported to be effective, but the unique anatomical and physiological features of the duodenum are associated with a higher incidence of severe complications compared with other sites. In addition, SNADETs requiring ESD are relatively rare, making it difficult, especially in regional hospitals, to accumulate sufficient cases and gain experience. To ensure safety while building experience with duodenal ESD, we introduced duodenal laparoscopic and endoscopic cooperative surgery (D-LECS), in which ESD is followed by laparoscopic suturing of the mucosal defect. We then gradually shifted to standalone duodenal ESD after stepwise training, including endoscopic closure techniques in colorectal ESD. This study aimed to clarify the role of D-LECS in the introduction of duodenal ESD in a Japanese regional hospital.

We retrospectively reviewed 37 patients with 37 SNADETs treated by D-LECS between September 2016 and November 2024, and 6 patients with 6 SNADETs treated by ESD alone from January 2025 onwards at our institution.

1. D-LECS cases were divided into an early phase (before national insurance reimbursement) with 12 lesions and a late phase (after reimbursement) with 25 lesions. Patient characteristics and treatment outcomes were compared between phases, including en bloc resection rate, R0 resection rate, dissection speed, intraoperative perforation, delayed bleeding, delayed perforation, and postoperative fever.
2. Treatment outcomes of standalone ESD cases were evaluated descriptively.

1. Patient characteristics, including age, sex, tumor size, tumor location, and malignancy rate, did not differ between the early and late D-LECS phases. En bloc resection was achieved in 100% of lesions in both phases. R0 resection rates were 16.7% in the early phase and 8.0% in the late phase, with no significant difference. Intraoperative perforation occurred in 41.7% and 12.0% of cases, respectively, showing a non-significant trend toward reduction in the late phase (p = 0.083). Postoperative fever occurred in 16.7% of early-phase cases and in none of the late-phase cases.
2. All 6 standalone ESD cases achieved R0 resection. One patient developed a perforation during clip closure of the mucosal defect; free air worsened on the following day, and surgical suturing of the defect was required. The remaining 5 patients experienced no major complications and were discharged on postoperative day 4.

In a Japanese regional hospital where case accumulation is challenging, stepwise skill acquisition through D-LECS for duodenal ESD, combined with training in endoscopic closure after colorectal ESD, appears useful for safely introducing standalone duodenal ESD. However, the risk of emergency surgery due to complications remains and requires careful attention. Close collaboration with surgeons is essential, and D-LECS may contribute to both technical training of endoscopists and improvement of treatment outcomes during the introductory phase of duodenal ESD.