Metal stent for refractory post-ES bleeding: Is this the ultimate treatment modality?

Endoscopic sphincterotomy (ES), which had been developed by Kawai [1], Classen [2], and Soma et al. [3], has been a very innovative and effective endoscopic procedure to date. However, ES has also inevitable post-procedural bleeding complications, the so-called “AchillesHills of ES.”Mirjalili et al. [4] previously demonstrated the distributions of the arterial supply of the major duodenal papilla and their relevance to ES according to their pathologic analysis of 19 cadaver pancreaticoduodenal specimens.Most of the arterieswere related to the antero-superior and postero-inferior quadrants of the major duodenal papilla, both at their point of entry into the duodenal wall or bile/pancreatic ducts (microdissection) and in their distribution 5mm from the tip of the papilla (histology) [4].Moreover, the combined10 and11oʼclock segments of the papilla (as viewed endoscopically) contained only 10% and 11% of all papillary arteries onmicrodissection and histology, respectively, with seven of 19 specimens having no arteries in this region. Based on their results, they advocated that arterial bleeding as a complication of ESmight be reduced by incising the papilla in the 10–11 oʼclock region rather than in the currently recommended 11–1 oʼclock position. However, the axis of the real major papilla is often rotatable, mainly counter-clockwise. Furthermore, a special anatomic situation (e.g., periampullary diverticula) causes confusion about the right axis of the major papilla. Thus, even if endoscopists believe that the 12 oʼclock position is at themajor papilla, this is not always true. These factors may lead to a wrong direction towards the papilla, causing post-ES bleeding. Thus far, large prospective studies have in fact reported that the incidence of active bleeding or ongoing oozing requiring endoscopic hemostasis ranges from 0.76% to 2.0% [5–7]. Several traditional techniques of endoscopic hemostasis for post-ES bleeding exist, namely, balloon tamponade, local injection of hypertonic saline-epinephrine, and thermal therapies such as argon plasma coagulation, bipolar coagulation, and/or clipping [8]. However, there is no consensus regarding the optimal endoscopic hemostatic technique for post-ES bleeding. Monotherapy or combination endotherapies produce very high rates of success for hemostasis, particularly in case of repeat therapies, but there are rare or only a few cases in which a conventional hemostatic technique is refractory. Traditionally, interventional radiology (arterial embolization) or surgical hemostasis is necessary. Shah et al. [9] and Itoi et al. [10] previously introduced use of a fully covered self-expandable metal stent (FCSEMS) as a new hemostasis technique for refractory post-ES bleeding. This technique presents a new concept of hemostasis achieved by mechanical compression using FCSEMS. In fact, previous data showed a very high success rate without any serious complications [9,10]. Most recently, Cochrane and Schlepp [11] conducted a retrospective non-randomized controlled comparative study between the FCSEMS group (n=23) and the non-FCSEMS group (n=44) in patients with post-ES bleeding after primary endoscopic intervention failure particularly in patients with a high risk of post-ES bleeding. Interestingly, although the FCSEMS treatment group had a significantly lower bleeding rate at 72 hours (0.66g/dL vs. 1.98g/dL; P<0.001), an increased proportion of patients with a high risk of bleeding (40%vs. 9%P=0.008), anda significantly increased proportion of patients with moderate severity of bleeding events (52% vs. 9% P=0.0002) were observed comparedwith the non-FCSEMS treatment group. The FCSEMS treatment group consisted of 9 patients with increased risk of bleeding but none had delayed bleeding compared with the 4 patients in the non-FCSEMS group, all of whom had increased risk of bleeding risk and developed delayed bleeding. Based on their results, they concluded that FCSEMS canprovidehomeostasis after