Ulcer Bleeding

Peptic ulcers represent the most common cause of upper GI bleed (around 60%) [11], and they require emergency endoscopic intervention to achieve prompt hemostasis. The mortality rate for patients hospitalized for upper GI bleed has been placed between 4.5% and 8.2% [12], making it a significant risk for patients. Endoscopic treatment is recommended for the treatment of ulcers with high-risk stigmata (Classed Forrest Ia and Ib) [13], whereas ulcers with an adherent clot should have the clot removed to evaluate the underlying lesion and treated accordingly [13, 14].

Endoscopic clip use for ulcer treatment has the added benefit of allowing the approximation of the ulcer margin [15]. Its effectiveness could be compromised by the presence of fibrosis at the base or around the ulcer, making it more rigid and more difficult to place the clips. Furthermore, ulcers located on the posterior wall of the duodenal bulb can make it harder to deploy clips effectively [16]. During the treatment of the ulcer, clots are usually removed prior to clipping to better visualize the target site of clip application. The clip is then opened and pointed at the base of a visible vessel, then pressed over it. Suction is then applied to capture more targets in before closing the clip. Finally, the clip is closed and deployed, bringing the tissues together and closing the lesion. More than one clip can be required to achieve proper hemostasis depending on the severity of the ulcer.

An over-the-scope clip could also be used for peptic ulcer hemostasis but requires an en-face approach, whereas through-the-scope clips could be used either en-face or tangentially with similar efficacy [17]. Applying an over-the-scope clip on an ulcer requires pressing the end of the endoscope over the lesion and turning the provided hand wheel clockwise. The open clip presently resting over the scope immediately releases and closes the tissue, aiming to achieve hemostasis.

Clips have been shown to be more effective than injection monotherapy for ulcer hemostasis, with a 78% reduction in bleeding recurrence and need for surgery [18], but are of comparable efficacy to thermo-coagulation [18, 19]. Clips do, however, have a lower risk of perforation when compared to thermo-coagulation, making them a very attractive alternative. Clips could also be used in combination with epinephrine injections to halt bleeding, although this did not show a statistically significant difference in preventing rebleeding compared to clipping monotherapy [18]. Epinephrine injections can be performed either before or after clip placement. Injections after clipping would however be preferable, since injecting prior to clipping would cause the target tissues to swell and may cause the clip to fall off prematurely as the swelling subsides.

Over-the-scope clips have also been shown to be effective in treating peptic ulcer bleeding [20]. A 2017 prospective randomized multicenter trial has shown in its preliminary results that the OTSC was superior than through-the-scope clip and epinephrine injection combination therapy [21]. Further studies still need to be performed, but the OTSC shows real promise in supplanting standard therapies for peptic ulcer bleeding.

Diverticular Bleeding

Diverticular hemorrhages are the most common cause of lower GI bleeds, constituting about 40% of total hospitalizations for LGIB [22, 23]. Although most bleeds resolve spontaneously, endoscopic intervention is sometimes required to stem the bleeding.

There are many options to endoscopically stop diverticular bleeds through clipping. Clips can be applied to close the diverticulum or directly on a bleeding vessel within it. Multiple clips could also be applied one next to each other to close a particularly large diverticulum. For bleeding occurring from a diverticular dome, a clip could be positioned so that one prong lay inside the diverticulum and the other on the outside. Closing the clip then cuts off supply from the vessel leading to the bleeding site [24]. The American College of Gastroenterology currently recommends clipping as the first-line hemostatic technique for diverticular bleeding [25].

Over-the-scope techniques have also been described for the closing of diverticular bleeding [26], where the clip is positioned center on the diverticulum with each prong resting on one edge of the diverticulum. Suction is performed to grab as much tissue as possible and the clip is released, clamping down behind the diverticulum bleeding area. This cuts off the blood supply to achieve hemostasis [27].

Clipping has been proven effective in managing acute diverticular bleeding [25]. It may be preferable to other hemostatic methods because of its lower risk for perforation and its ability to minimize tissue damage [25]. The rate of hemorrhage after clipping was shown to be about 17% [24, 28] with no early bleeding recurrence (defined as <30 days). Clips could be used in this case as markings to determine whether the hemorrhage was de novo or reoccurring. Current guidelines therefore suggest performing hemostasis (preferably clipping) if a non-bleeding visible vessel, a difficult-to-remove adherent clot, or active bleeding is found during colonoscopy [25].

Dieulafoy’s Lesions

Dieulafoy’s lesions account for less than 6% of non-variceal upper gastrointestinal bleeding [29, 30]. They are associated with a 5% mortality rate due to exsanguination [31], posing a real risk to patient safety, and therefore require prompt hemostasis to improve outcomes. Clipping is one such option to achieve hemostasis in these patients.

Hemoclipping was found to be more effective than epinephrine injection for Dieulafoy lesion hemostasis and significantly reduced the chance of bleeding recurrence following treatment [32]. The success rate of clips for treatment of these lesions is well above 90% with a very little risk of rebleeding [32–34]. Clipping is therefore very useful as a first-line treatment for Dieulafoy’s lesions. One downside to this method is that some lesions are in hard-to-reach places, such as the lesser curvature of the stomach, the fundus or on the posterior bulb of the duodenal wall. A skilled endoscopist is therefore needed to deploy and successfully use the clip for these lesions. Finally, clips and endoscopic band ligation were similarly effective in treating Dieulafoy’s lesions [30]. Both methods can be considered for such cases.

Successful over-the-scope clip treatment for Dieulafoy bleeding has been described [17, 35, 36]; however, more research needs to be done to compare its efficacy to existing through-the-scope clips and other hemostatic methods.

Mallory-Weiss Syndrome

Mallory-Weiss tears are an uncommon cause of upper GI hemorrhage. They constitute around 5% of all causes of upper GI bleeding [37, 38]. Mechanical hemostasis through clipping offers a practical solution for treating both these tears and the bleeding associated with them.

Endoscopic clipping has been found to be effective for the treatment of Mallory-Weiss tears [37–39], with an efficacy similar to endoscopic band ligation [40]. The advantages of using mechanical clipping for the treatment of Mallory-Weiss syndrome hemorrhage include the ability to stop the bleeding as well as closing the physical tear responsible for that bleeding [39]. It may also be a preferable technique to thermo-coagulation, as the esophageal wall is thin and more prone to full thickness perforation, especially if the mucosal wall is already torn.

Over-the-scope clips can also treat Mallory-Weiss tears, with multiple reports showing successful application of the devices to halt bleeding [17, 41]. It is slowly becoming another tool in the endoscopist’s armamentarium to manage these types of lesions.

Post-Polypectomy

Post-polypectomy bleeding is an important complication after polyp removal, with an incidence rate between 3% and 8% [42, 43] and delayed bleeding usually occurring within 14 days after polypectomy [44]. Although immediate bleeding can be successfully treated using clipping, current practice can include prophylactic clipping of certain lesions to prevent future hemorrhage. For pedunculated polyp bleeding, the best way to achieve hemostasis is to deploy the clip across the stalk or to clip the base of the polyp. This effectively cuts off the blood supply from the feeding vessel. For sessile polyps, the bleeding region should be clipped first and the lesion on the mucosa entirely closed afterward. Multiple clips could be used for either of these procedures to achieve the desired effect [45].

Categories to stratify polyps for prophylactic clipping are dependent on polyp size (small/mid-sized polyps and large polyps) and polyp morphology (pedunculated/flat polyps).