Background and Aims: Endoscopic intermuscular dissection (EID) is effective for lesions penetrating the submucosal layer. However, EID using a single-use endoscope has not been reported. We present two cases of EID performed with a novel single-use endoscope to evaluate its safety and efficacy.
Methods: We report on two patients with early-stage rectal cancer who underwent EID using a single-use colonoscope (EndoFresh DC-T300L). We analyzed the success of en bloc and R0 resection, and the occurrence of complications.
Case 1: A 67-year-old male with a history of hyperthyroidism and atrial fibrillation. A rectal mass (approx. 20 mm in diameter) was identified 8 cm from the anal margin. Color Doppler ultrasound suggested infiltration of the submucosal layer. EID was performed. The inner circular muscle was incised, and the outer longitudinal muscle was exposed as the dissection endpoint. Result: Complete en bloc and R0 resection were achieved. The pathological result was moderately differentiated adenocarcinoma (pT1, infiltration depth approx. 3 mm, negative margins). Blood loss was <1 mL. No postoperative complications (bleeding, perforation, or infection) occurred. Radical surgical resection was performed 8 days postoperatively.
Case 2: An 82-year-old female with a history of hypertension, coronary heart disease, and diabetes mellitus. A rectal mass (approx. 25 mm in diameter) was found 6 cm from the anal margin. Rectal ultrasound and pelvic MRI suggested local malignant transformation (uT1–2/T2N0). EID was performed with the same technique. Result: Complete en bloc and R0 resection were achieved. The pathological result was villous-tubular adenoma with malignant transformation to moderately differentiated adenocarcinoma (pT1, infiltration depth approx. 8 mm, negative margins). Blood loss was <10 mL. No postoperative complications occurred. The patient was discharged 2 days postoperatively.
Conclusions: The use of the single-use endoscope was safe and effective for EID in these two cases. This approach may offer advantages, particularly in preventing perforation-related extra-abdominal infection, which is a concern with EID due to manipulation within the muscularis propria layer. Further studies are needed to validate these findings.