Diverticular bleeding is a common cause of acute lower GI bleeding, accounting for 20% to 65% of such episodes[4-7]. Erosion into the vasa recta that traverse the neck and dome of diverticula can lead to brisk, dramatic bleeding. Endoscopic management of diverticular bleeding can be challenging for multiple reasons including the inconvenience of rapid bowel preparation, the difficulty of carefully examining each diverticulum in the colon, identification of true stigmata of recent hemorrhage (SRH), and achieving hemostasis of such small lesions within diverticula.
Urgent endoscopy: In hemodynamically stable patients with lower GI bleeding, urgent colonoscopy should be performed within 8 to 24 h of presentation (or sooner, if possible) following sufficient bowel preparation[8,9]. The likelihood of identifying SRH is higher when early colonoscopy is performed, which, in turn, increases the chance for definitive hemostasis. Two meta-analyses in 2017 compared early and late colonoscopy for patients presenting with lower GI bleeding and found no reduction in rebleeding rates, transfusion requirements, and other important outcomes, but did show an increased rate of endoscopic intervention[11,12]. Other studies have also directed attention toward the possible low impact of early colonoscopy on patient outcomes in lower GI bleeding[13-18], but none of these investigations focused specifically on diverticular bleeding. In our experience, if diverticular bleeding can be identified and treated, the benefits are clear.
Visualization and identification: The SRH seen in diverticular bleeding are similar to those seen in the upper GI tract. Active bleeding, visible vessels, adherent clots, and pigmented spots can all be seen associated with diverticula. Localization of such lesions can be difficult given the potential for numerous diverticula throughout the colon that require investigation, inadequate bowel preparation, and the fact that diverticular bleeding frequently stops spontaneously or can be intermittent. Published rates of SRH identification vary widely, with one notable study listing SRH identification in 17% of cases. The study by Niikura et al also found factors useful in SRH identification, which included urgent colonoscopy, expert endoscopists, the use of a transparent cap, and water jet use. Based on current literature and experience, the most reasonable approach is to optimize bowel preparation with use of a nasogastric tube if the patient is unable to tolerate oral prep, and to have a team member confirm successful bowel preparation prior to attempting colonoscopy. During colonoscopy, each diverticulum should be carefully examined using a transparent cap attached to the colonoscope and with water washing and infusion into diverticula as necessary. Another technique that can be attempted is inversion of diverticula by suctioning into the distal cap attachment. Using these methods, a satisfactory examination of the colon for stigmata of recent diverticular hemorrhage should be possible.
Endoscopic treatment: Current American College of Gastroenterology practice guidelines recommend the use of through-the-scope (TTS) clips for the treatment of diverticular bleeding due to the safety and ease of use compared to other modalities like band ligation. Current American Society of Gastrointestinal Endoscopy practice guidelines suggest the use of a heater probe or bipolar coagulation alone or in combination with epinephrine followed by tattooing near the lesion for future identification in the case of rebleeding. TTS clips and endoscopic band ligation (EBL) are alternatives to thermal coagulation and endoscopic band ligation (EBL) is also discussed. Clip placement near culprit diverticula can also serve as a radiographic landmark during angiography (were it to become necessary).
TTS clips (Figure 1) are frequently used to treat diverticular hemorrhage, and they have been shown to provide satisfactory primary and rebleeding hemostasis after initial clipping. Being mindful of the anatomy of diverticula and nearby arteries is important during hemostasis attempts. Clips can be used in multiple ways, for example clipping a vessel in the neck or dome of a diverticulum or clipping the mouth of a diverticulum closed. If SRH are not readily visible or accessible, we recommend the use of a clear cap (i.e., distal attachment) for improved navigation and examination of diverticula and facilitatation of treatment.
Figure 1 Endoscopic treatment of diverticular bleeding.
A: Diverticula with fresh blood nearby; B: Interrogation of the diverticula reveals a visible vessel within a diverticulum; C: Through-the-scope clipping of the visible vessel following submucosal 1:10000 epinephrine injection; D: Additional clipping performed to secure more durable hemostasis.
EBL is another available treatment modality. If SRH can be identified, then a TTS clip is placed to mark the site, and the colonoscope is withdrawn for placement of a band ligator device. After return to the bleeding site, the diverticulum is inverted into the cap of the ligator and a band is deployed. This technique may be limited or infeasible in the case of diverticula with narrow orifices or with diverticula in the right colon.
A recent meta-analysis comparing coagulation, EBL, and TTS clips in the treatment of diverticular bleeding demonstrated comparable rates of initial hemostasis and prevention of early rebleeding between the three treatment modalities, and that EBL may be more likely to prevent IR or surgery than TTS clip use. A prospective trial comparing TTS clips to EBL showed lower 1 year recurrent bleeding in the EBL group, but no statistically significant difference in early rebleeding.
A newer technique that has been described is the use of a detachable endoscopic snare (Endoloop, HX-20Q-1; Olympus), most commonly used for reducing bleeding during resection of large, pedunculated colon polyps. The bleeding site is located with a colonoscope equipped with a transparent cap, and then a clip is used to mark the site. The SRH is placed at the location of the instrument channel, suction is used to invert the diverticulum into the cap, and then the detachable snare is deployed over the base of the diverticulum to achieve hemostasis. In a large, multicenter prospective study, detachable snare deployment was successful in 82% of the 123 included patients. The most common reason for failed treatment was insufficient suction. Early recurrent bleeding occurred in 7.9% of patients treated with detachable snare ligation. There was one episode of diverticulitis related to the treatment.
The endoscopic treatment modality choice should be based on endoscopist expertise, but efforts for early hemostasis should be made. In cases of rebleeding after initial hemostasis attempts, repeat colonoscopy should be performed for another careful examination of the entire colon and terminal ileum. If a bleeding site can be identified, then treatment should be performed.