Is there an optimal technique to treat the bleeding diverticulum? Is diverticular bleeding a recurrent disease?

Colonic diverticular bleeding is the most common cause of lower gastrointestinal bleeding in adults [1,2]. Bleeding can occur from an injured branch of the submucosal plexus vessels at the neck or along the dome of the diverticulum [3]. While the majority (approximately 80%) of bleeding is self-limited, some patients can develop massive bleeding–perhaps because the submucosal plexus is derived from a sizable submucosal artery. Endoscopically, the stigmata of recent bleeding from the diverticulum may be immediately visible [4] or may need to be exposed by inverting the diverticulum [5]. Inversion is achieved by using a cap, which, with gentle suction, will lead the diverticulum into it. The waterjet is very useful towash the inverted diverticulum and provide optimal visualization. Most of the recent endoscopic interventions to treat diverticular bleeding have centered on two techniques: clipping and ligation. Four techniques of endoscopic clipping have been described: (1) clips are applied directly onto visible stigmata of recent bleeding [4], (2) clips are applied along the neck when the stigmata is within the dome [6], (3) clips are deployed to approximate the mouth of the diverticulum, also when the stigmata is within the dome [7], and (4) a clip is deployed from within a cap, which is used to invert the diverticulum, to expose the stigmata, and to clip it [5]. Two ligation techniques have been described: (1) endoscopic band ligation in which the diverticulum is inverted into the banding cap and subsequently banded [8], and (2) endoscopic detachable snare ligation inwhich a small detachable loop is used to ligate the inverted diverticulum in lieu of the band [9]. These techniques have been found to be safe. In fact, we are not aware of a report of perforation with either technique in the treatment of bleeding colonic diverticulum. However, the short-term (<30 days) recurrent rebleeding rates vary. The short-term rebleeding rates after clipping range from 0% [5] to 34.5% [7]. The lowest rate was observed when the clips were applied directly onto the bleeding vessel, around the neck of the bleeding diverticulum, or from within a cap.The highest rate occurred when the clips were used to approximate the opening of the diverticulum. It is conceivable that the approximation of the mouth of the diverticulum had led only to a temporary tamponade effect. With time, as the clips fall off, the injured vessel [3], which is unable to heal, rebleeds. The short-term rebleeding rates after band ligation range from 3.7% [10] to 15% [11]. In this issue, Nakano et al. describe the short-term risk of rebleeding after a successful endoscopic band ligation [12]. They used a historical group as the comparison and found that endoscopic band ligation was associated with less early rebleeding than endoscopic clipping (14% vs. 38%, respectively). However, the majority of the endoscopic clipping was done by closing the mouth of the diverticulum. Thus, the comparative group appeared to have been treated with a potentially less efficacious technique. Therefore, the question of which endoscopic method should be used to treat a bleeding diverticulum has not yet been answered. Future studies will also need to employ a randomized design. Ikeya and colleagues from the same group studied the etiology and risk factors for short-term rebleeding after band ligation [13]. Very early rebleeding (e.g. within 12 hours after banding) was reported to occur from early band dislodgment, banding the wrong diverticulum, or development of an ulcer at the banded site. When rebleeding occurred a fewweeks later, they found that bleeding occurred from other diverticulum. They studied the predisposing factors, but the number of patients (n=15) seemed too small to provide a meaningful result.