Use of a Side-Viewing Endoscope for Superficial Non-Ampullary Duodenal Epithelial Tumors Located in the Groove Area

Abstract

Forward-viewing (FV) endoscopy shows limitations in the detection of superficial non-ampullary duodenal epithelial tumors (SNADETs) located on the ampullary side [1, 2]. Particularly, the area above the papilla, called the groove area (Figure 1a–c), often prevents operators from managing SNADETs endoscopically. These failures are attributed to their horizontal orientation relative to the scope. Recent statements have recommended the use of a side-viewing (SV) endoscope to perform papillectomy for ampullary tumors [3, 4]. Furthermore, it has been reported that the use of an SV-endoscope is a viable option for endoscopic resection (ER) of lesions in the medial part of the descending duodenum, even in non-ampullary tumors [5, 6]. However, there have been no obvious reports of ER using an SV endoscope for SNADETs located in the groove area. Herein, we introduce two cases in which the ER technique, similar to endoscopic papillectomy using an SV endoscope, was efficacious in completely resecting SNADETs located in the groove area by obtaining an overall view of the tumors.

Case 1: A 54-year-old male presented with an 8-mm SNADET located in the groove area. While the anal side of the lesion was invisible to the FV endoscope (Figure 1d), the SV endoscope (TJF-Q290V; Olympus, Tokyo, Japan) enabled visualization of the entire tumor (Figure 1e) and facilitated cold snare polypectomy (Figure 1f) followed by defect closure using hemoclips (Sure Clip; Micro-Tech Co. Ltd., Nanjing, China). Histopathological examination confirmed the curative resection of a moderate-grade tubular adenoma.

Case 2: A 74-year-old male presented with a 15-mm SNADET located in the groove area that was incidentally detected during treatment for common bile duct stones. In contrast to the limited view of the tumor by the FV endoscope (Figure 1g), the SV endoscope enabled tumor visualization (Figure 1h), facilitating subsequent endoscopic mucosal resection (Figure 1i) and clip closure. Histopathological examination confirmed curative resection of the high-grade tubular adenoma.

The present technique has several limitations. Compared to the FV endoscope, ER using the SV endoscope for tumors in the groove area may be only indicated for small-sized tumor less than 15 mm as described in the present cases. While underwater endoscopic resection are acceptable techniques for 10 < tumor ≦ 20 mm, endoscopic submucosal dissection (ESD) is indicated for suspicious carcinoma with larger tumors of more than 20 mm in size [7]. Because the technical principle is based on papillectomy, we consider that technical difficulties associated with tumor resection and wound closure, and risks of complications would be almost similar to papillectomy. However, the size limitation and technical aspects should be further investigated.

In summary, the strength of this study is the improvement of the endoscopic view in the groove area owing to the shift from FV endoscopy to SV endoscopy. Consequently, the technique using SV endoscopy highlights its superiority in visualizing and accessing lesions that are difficult to manage with FV endoscopy, ultimately improving the effectiveness and safety of endoscopic treatment. SV endoscopy may be an alternative tool for reliably treating SNADETs located in the groove area.

Written informed consent was obtained from the patients for the publication of this report and accompanying images.

The authors declare no conflicts of interest.