Introduction
Endoscopic self-expandable metallic stent (SEMS) placement for malignant colonic obstruction is commonly performed using the through-the-scope (TTS) technique. However, strategies to reduce radiation exposure remain a clinical concern. We developed a novel technique, Direct-Vision Stenting (DVS), using a new thin therapeutic scope (Fujifilm EG-840TP: outer diameter, 7.9 mm; working channel, 3.2 mm) for malignant rectosigmoid obstructions [1]. After advancing the scope through the stricture, the stent is partially expanded under direct vision, then anchored and gradually released under endoscopic visualization while withdrawing the scope. This technique may minimize radiation exposure by eliminating the need for fluoroscopic confirmation of guidewire placement and contrast injection.
Aims & Methods
This study aimed to evaluate the feasibility of the DVS technique. From January 2024 to March 2025, SEMS placement for malignant rectosigmoid obstructions was initially attempted using the DVS technique. If DVS was unsuccessful, conversion to the conventional TTS technique (without direct visualization of the oral lumen or beginning of the stent expansion) was permitted. Ten consecutive patients were prospectively evaluated for technical success, adverse events, fluoroscopy time, and total procedure time (from scope arrival at the lesion to stent deployment).
Results
The median age was 81 years, and 4 patients were men. The obstruction was located in the rectosigmoid colon in 3 patients and the sigmoid colon in 7. Five procedures were performed for palliative purposes. The technical success rate of the DVS technique was 60%. All unsuccessful cases were resolved by conversion to the conventional TTS technique. Reasons for DVS failure included poor bowel preparation (n = 1), failure of scope advancement (n = 2), and severe colonic angulation (n = 1). No adverse events were observed, and all patients experienced symptomatic relief. Among successful DVS cases, median procedure time was 17 minutes, and fluoroscopy time was 4 minutes. In comparison, in 17 cases treated with the conventional TTS technique prior to the study period, the median procedure and fluoroscopy times were 15 and 11 minutes, respectively, suggesting a trend toward reduced fluoroscopy time with the DVS technique.
Conclusion
The DVS technique using EG-840TP achieved a 60% success rate for malignant colonic obstructions in the rectum or sigmoid colon and allowed safe conversion to the TTS technique when necessary. In appropriate cases, this approach may reduce fluoroscopy time and overall radiation exposure.
References
[1] Sawai Y, Shimada T, Yamagata T, et al. Innovative techniques using a novel thin scope for stent placement in malignant colonic obstruction with severe angulation deformity. Endoscopy 2024; 56: E866–E867.