The “double string” sign: a warning image after cold endoscopic mucosal resection

Abstract

A 52-year-old man underwent screening colonoscopy. A sessile serrated lesion (Paris 0-Is, NICE-1; 17 mm diameter) was observed in the right colon. After submucosal injection with gelofusine plus indigo carmine, en bloc cold endoscopic mucosal resection (cold-EMR) was attempted using a 25-mm braided snare (SnareMaster SD-210U-25; Olympus, Tokyo, Japan) (▶ Fig. 1). After snare closure, moderate traction of the snare sheath was applied to remove the lesion; however, the lesion remained trapped due to a large amount of tissue caught. The snare was repositioned slightly, and resection was successful. On inspection of the mucosal defect, the submucosal layer was observed with apparent "bubble sign" after waterjet irrigation (▶ Fig. 2 a, ▶ Video 1), followed by a "double string" sign, suggesting exposure of damaged muscle fibers (▶ Fig. 2 b). After insufflation and water irrigation, these muscle fibers separated showing deep muscular injury with visible serosa (▶ Fig. 2 c). The defect was immediately closed with endoscopic clips (▶ Fig. 2 d). The patient was monitored for 4 hours and discharged with prophylactic antibiotics and no symptoms. No complications occurred. Histology confirmed a 21 × 12 × 2 mm specimen and suspicion of serrated lesion without dysplasia. E-Videos Video 1 The "double string" sign and perforation after cold endoscopic mucosal resection. ▶ Fig. 1 Sessile serrated lesion Paris 0-Is, NICE-1, in the right colon. ▶ Fig. 2 The mucosal defect after cold endoscopic mucosal resection. a Submucosal layer with apparent "bubble sign" after waterjet irrigation. b Injured muscle layer, "double string" image. c Perforation site. d Complete endoscopic closure with clips. Nogales Óscar et al. The "double string" warning sign after cold EMR … Endoscopy

Curriculum for training in endoscopic mucosal resection in the colon: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

“…Level of agreement 90 %. (v) Be aware that perforation of the muscularis propria after cold snare polypectomy is extremely rare and described only in case reports [105,106]. This should be treated appropriately if it occurs.…”

Modified endoscopic mucosal resection techniques for treating precancerous colorectal lesions

“…Intraprocedural bleeding may occur, usually in the form of minor oozing after resection; however, in most cases it lacks major clinical significance and can be easily managed [ 40 , 41 ]. Although sporadic cases have been reported [ 42 ], cold resection also bears zero risk for deep muscular layer injury, perforation or delayed bleeding [ 40 ]. Although data remain scarce, cold resection might be valuable for specific patient populations, such as those receiving anticoagulant/antiplatelet medication.…”

Through-the-Scope Clips Are Indispensable in Treating Deep Mural Injury From Colorectal EMR

“…Furthermore, when cold piecemeal EMR is pursued, dependent pooling may be less of a concern, because perforation has only been reported in very rare instances with this technique. 10 Drawing from surgical experience, completely closing colonic perforations (that may otherwise result in delayed peritonitis and abscess formation) is critical when compared with limited upper GI tract perforations, which can sometimes resolve, especially in retroperitoneal locations (posterior esophagus and stomach), even with less-than-complete closure. Although the European Society of Gastrointestinal Endoscopy recommends use of TTSCs for closure of small (10 mm) colorectal perforations and over-the-scope clips (OTSCs) for larger ones, unless the lesion has been completely resected, using an OTSC may close a perforation but it often renders completion EMR difficult or impossible.…”