Acute obscure–overt gastrointestinal bleeding: capsule endoscopy first?

Every experienced clinical gastroenterologist can recall a recent case of this particular type of patient: presenting with an acute gastrointestinal bleeding, and with negative findings on initial “emergency” upper endoscopy and colonoscopy. In quite a number of these patients the gastrointestinal bleeding is recurrent or ongoing, necessitating further diagnostics to locate the source of bleeding, followed by guided therapeutic intervention. We know that about 5 % of all patients with an iron deficiency anemia with a suspected gastrointestinal bleeding, whether presenting with visible or nonvisible blood loss, will finally be classified as having an obscure gastrointestinal bleeding (OGIB). The percentage of patients with obscure – overt gastrointestinal bleeding (OOGIB) is not exactly known, but is likely to be a smaller portion of all patients with OGIB. As in OGIB patients, in OOGIB patients the logical next step is evaluation of the small bowel, for identification of a likely small bowel lesion as the source of the bleeding. In recent years, since the introduction of capsule endoscopy in 2000, followed by double-balloon enteroscopy (DBE) in 2001, the earlier-used push enteroscopy and laparotomy-assisted enteroscopy have both been widely replaced by these two newer techniques. In more recent years, single-balloon and spiral enteroscopy have been added to the enteroscopic options, generally referred to as “device-assisted enteroscopy” (DAE). Radiological options are abdominal CT angiography with contrast, conventional intra-arterial contrast angiography, and “classical” tagged (technetium-99m-labeled) red blood cell scan. To date, no studies have compared the use of any of these, mainly diagnostic, techniques in this particular and challenging group of patients.

The first presented prospective study using capsule endoscopy in patients with OOGIB (n = 26), as part of a total of 100 patients with OGIB, showed positive findings on capsule endoscopy in 95 % of the OOGIB patients [1]. A more recently published retrospective study, using DBE as a primary tool in patients with OOGIB, showed again a high percentage of positive findings, in 90 % of investigated patients; however, the number of patients was relatively small (n = 10). In the latter study, endoscopic therapy was performed in all patients, being reported as successful in all but one patient; i. e., hemostasis was reached after DBE in the case of vascular malformations, and in cases where small-bowel tumors were found, clinically active bleeding was controlled until elective surgery was performed [2].

In this issue of Endoscopy, the Digestive Endoscopy Unit from Rouen, France, presents data from a large retrospective study, focusing on the diagnostic yield of “emergency” capsule endoscopy in patients presenting with an OOGIB [3]. Over a 7-year period (2003 – 2010) they were able to retrieve, from a large database of over 5700 patients hospitalized for gastrointestinal bleeding, a total of 55 patients presenting with OOGIB, all of whom underwent capsule endoscopy within 48 hours of presentation. In 75 % of these patients an active bleed or stigmata of recent bleeding were identified. Overall, in 67 % of patients the actual cause of the gastrointestinal bleeding was identified. Fresh blood or an absence of lesions/abnormalities were reported in the remaining patients, respectively 22 % and 11 %. Therapeutic interventions were consequently performed in 42 patients, mainly endoscopic therapy (n = 30). At long-term follow-up (median 36 months, range 9 – 85 months), 11 % of patients had recurrent gastrointestinal bleeding, giving an overall primary clinical success rate of 89 %. The patients presenting with re-bleeding were all patients earlier diagnosed with small-bowel angiodysplasia. These data show that the diagnostic yield of an “emergency” capsule endoscopy in OOGIB patients is high. The overall clinical outcome seems very good: almost 90 % of patients did not re-bleed. The authors have performed a very interesting study and presented valuable data, and the retrospective setting does not devalue the importance of the outcomes of this study. The authors conclude that capsule endoscopy is a key tool in OOGIB patients, and that capsule endoscopy and DBE are complementary in these settings.

One can debate about the latter statement of the presenting authors. The grounds put forward by the authors to prefer capsule endoscopy to DBE – that capsule endoscopy is noninvasive and less time-consuming than DBE – can both be easily challenged. Firstly, in the case of the majority of positive findings by capsule endoscopy, this noninvasive procedure is followed by an invasive procedure, whether DAE, surgery, or radiological intervention. Thus, the capsule endoscopy is often “additional” and in the majority of cases does not result in less invasive therapy overall. Secondly, capsule endoscopy is still relatively time-consuming: the procedure itself takes about 8 hours, leading to an overall delay of at least 8 – 9 hours, including a minimum reading time of 1 hour. A DAE procedure can be performed earlier, without delays, and is shorter in overall duration. Another proposed advantage of the capsule-endoscopy-first strategy is that it guides the approach for the next step of therapeutic intervention: antero- or retrograde enteroscopy, or surgical or radiological therapy. However, in general practice an anterograde enteroscopy procedure is often considered first in these patients, as historical data have shown that the majority of lesions are located in the proximal range of the small bowel. In this study by Lecleire et al. [3], too, in 78 % of the cases the lesions were located in the jejunum, easily reached with an anterograde enteroscopy procedure. Another issue, not mentioned by the authors, is the important one of cost-effectiveness, as an additional capsule endoscopy will certainly increase overall costs. An earlier published study has already shown that a primary DBE strategy in OGIB is cost-effective, and this is with a lower expected diagnostic yield overall in OGIB as compared to OOGIB patients [4].

Another advantage of DAE is that with optimal flushing and insufflation of the small bowel during this procedure, some diagnostic limitations of capsule endoscopy can be overcome, which is likely to lead to an even higher diagnostic yield. In the case of small-bowel tumors, DAE with additional histological biopsies can provide pivotal information for the next step of therapy, and with tattoo inking or clipping the lesion can be marked for possible surgery in the near future. Alternatively, conventional intra-arterial contrast angiography also combines diagnostic capacities with therapeutic intervention options. The major drawback of the latter option is that it lacks the sensitivity to differentiate purely vascular causes, e. g., angiodysplasia or varices, from small-bowel tumors or ulcerative lesions. The latter findings were reported as the cause of OOGIB in over 20 % of patients in the Lecleire et al. study [3].

Thus, although the study of Lecleire et al. as presented in this issue of Endoscopy shows very promising data about the use of “emergency” capsule endoscopy in OOGIB patients, the debate about using capsule endoscopy or DAE first in these patients is not yet closed. Since the a priori chance of identifying a bleeding source in OOGIB patients is quite high, a tool combining excellent diagnostic qualities with “same-procedure” therapeutic properties is favored. In centers where DAE is readily available and with expertise in therapeutic DAE procedures, a primary DAE procedure could be considered in OOGIB patients. In addition, preferably prospective studies are needed to evaluate the role of both techniques in this particular challenging patient group.

• References

• 1 Pennazio M, Santucci R, Rondonotti E et al. Outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy: report of 100 consecutive cases. Gastroenterology 2004; 126: 643-653
• 2 Mönkemüller K, Neumann H, Meyer F et al. A retrospective analysis of emergency double-balloon enteroscopy for small-bowel bleeding. Endoscopy 2009; 41: 715-717
• 3 Lecleire S, Iwanicki-Caron I, Di-Fiore A et al. Yield and impact of emergency capsule enteroscopy in severe obscure-overt gastrointestinal bleeding. Endoscopy 2012; 44: 337-342
• 4 Gerson L, Kamal A. Cost-effectiveness analysis of management strategies for obscure GI bleeding. Gastrointest Endosc 2008; 68: 920-936