Reply to Mavrogenis et al.

We would like to thank the authors for their instructive comments.

We thank Mavrogenis et al. [1] for their interest in our article and their clinically relevant comments regarding the utility of capsule endoscopy in overt obscure gastrointestinal bleeding [2]. Small-bowel tumors are the second most common small-bowel lesion causing obscure gastrointestinal bleeding and account for 5 % – 10 % of cases of small-bowel bleeding [3]. Gastrointestinal stromal tumors (GISTs) often form solid subserosal or intramural masses, sometimes ulcerating or eroding vessels but rarely growing into the lumen [2] [3]. Therefore, gastrointestinal bleeding (acute or chronic) is the most common clinical presentation of GISTs while nonspecific symptoms, such as obstruction, invagination, perforation, or anemia occur in approximately 20 % of cases [2] [3]. We fully agree with Mavrogenis et al. that in cases of more proximal location of lesions there is a real possibility of these lesions being missed by capsule endoscopy due to the rapid capsule transit, bile and/or bubble artifacts, relatively poor luminal distension, and predominantly submucosal growth, generally with intact or only minimally damaged mucosa [2] [3]. Given the comparable diagnostic yield of capsule endoscopy and DBE in the evaluation of obscure gastrointestinal bleeding, there are always the questions of whether these two are competing or complementary technologies and how they should be incorporated in everyday clinical practice. Reports indicate that DBE is the most cost-effective approach for the evaluation of obscure gastrointestinal bleeding especially in emergent cases with massive bleeding, where DBE should be selected over capsule endoscopy, to prevent delay in endoscopic therapy [4] [5] [6] [7] [8].

Until now, most of the studies in the literature on the use of computed tomography (CT) in the evaluation of gastrointestinal bleeding have focused on patients with acute bleeding [9]. Recent advances in CT technology have greatly expanded the diagnostic role of CT angiography for various pathologic processes. Although still undergoing study, CT angiography seems to be a promising noninvasive diagnostic tool in the evaluation of obscure gastrointestinal bleeding, particularly the overt variant. Strengths of this technique include noninvasiveness and sensitivity for low rates of bleeding (0.5 mL/min) [9]. CT angiography is rapid and easy to perform and it should be considered in such cases. CT angiography can also assist in determining the endoscopic approach, especially when clinical location of bleeding to the upper or lower gastrointestinal tract is difficult or unreliable. This situation can occur because endoscopy often fails to visualize the exact focus of bleeding when massive bleeding (> 1 mL/min) occurs, since excessive blood or clots in the gastroduodenal tract impair the endoscopic view [9]. Furthermore, it is well known that as most GISTs have an exophytic growth, CT imaging is more useful than endoscopy and barium studies to evaluate the extent and the size of the tumor. Thus, in addition to the endoscopic standard work-up, multidetector CT seems to be recommended for obscure bleeding indications [9]. The precise role and timing of each procedure in these patients requires prospective trials with cost–effectiveness analysis. However, until such trials become available we will continue to rely on our clinical instinct and the useful cases such as the one presented by our group and by Mavrogenis et al. [1] [2].

References

• 1 Mavrogenis G, Coumaros D, Ranard C et al. Jejunal gastrointestinal stromal tumor missed by three capsule endoscopies.  Endoscopy. 2011;  43
• 2 Jovanovic I, Krivokapic Z, Menkovic N et al. Ineffectiveness of capsule endoscopy and total double-balloon enteroscopy to elicit the cause of obscure overt gastrointestinal bleeding: think GIST!.  Endoscopy. 2011;  43 (Suppl 2) 91-92
• 3 Caterino S, Lorenzon L, Petrucciani N et al. Gastrointestinal stromal tumors: correlation between symptoms at presentation, tumor location and prognostic factors in 47 consecutive patients.  World J Surg Oncol. 2011;  9 13
• 4 Sandvik O M, Soslashreide K, Kvaloslashy J T et al. Epidemiology of gastrointestinal stromal tumours: Single-institution experience and clinical presentation over three decades.  Cancer Epidemiol. 2011 (Apr 11);  [Epub ahead of print]
• 5 Somsouk M, Gralnek I M, Inadomi J M. Management of obscure occult gastrointestinal bleeding: a cost-minimization analysis.  Clin Gastroenterol Hepatol. 2008;  6 661-670
• 6 Barkun A N, Bardou M, Kuipers E J et al. International Consensus Upper Gastrointestinal Bleeding Conference Group. International consensus recommendations on the management of patients with nonvariceal upper gastrointestinal bleeding.  Ann Intern Med. 2010;  152 101-113
• 7 Rondonotti E, Pennazio M, Toth E et al. European Capsule Endoscopy Group; Italian Club for Capsule Endoscopy (CICE); Iberian Group for Capsule Endoscopy. Small-bowel neoplasms in patients undergoing video capsule endoscopy: a multicenter European study.  Endoscopy. 2008;  40 488-495
• 8 Mergener K, Ponchon T, Gralnek I et al. Literature review and recommendations for clinical application of small-bowel capsule endoscopy, based on a panel discussion by international experts. Consensus statements for small-bowel capsule endoscopy, 2006/2007.  Endoscopy. 2007;  39 895-909
• 9 Laing C J, Tobias T, Rosenblum D I et al. Acute gastrointestinal bleeding: emerging role of multidetector CT angiography and review of current imaging techniques.  RadioGraphics. 2007;  27 1055-1070