Provocative mesenteric angiography for gastrointestinal hemorrhage

Mesenteric angiography with transcatheter embolization can be a highly effective means of controlling gastrointestinal bleeding (GIB) when a source of hemorrhage is identified. However, given the intermittent nature of hemorrhage, a majority of cases of mesenteric angiography performed for GIB fail to demonstrate active bleeding. One approach for increasing the positive diagnostic rate is that of provocative angiography. Here we report our recent experience and outcomes with this protocol. A protocol for provocative angiography at a major academic medical center was developed and standardized as follows. In all cases at least one prior negative mesenteric arteriogram without provocation has been performed, any contraindications to the thrombolytic agent, tissue plasminogen activator (tPA), are excluded and surgical backup is obtained. The superior mesenteric artery is selectively catheterized and injected with 5000 units of heparin and 100 micrograms of nitroglycerin. Subsequent DSA is performed. If no source of hemorrhage is identified, 10 mg of tPA are administered via the catheter and repeat angiography is performed. If negative, the inferior mesenteric artery is catheterized and an additional 10 mg of tPA are administered. The total dose of tPA is limited to 20 mg. 19 cases of provocative mesenteric angiography were performed from June 2008 through September 2013. Of these, 14 (74%) were negative despite the provocative maneuvers. 5/19 (26%) demonstrated active contrast extravasation. Of these positive cases, 3 (60%) were successfully embolized at the time of angiography. In one case, the decision was made in conjunction with the surgical staff to defer embolization in favor of surgery. In the second case, a very small focus of bleeding was identified in distal arterial branches which could not be safely accessed. Provocative angiography can be performed safely, without causing life-threatening hemorrhage. By provoking hemorrhage in a controlled environment, positive rates are increased and the majority of these patients can be treated immediately. This can reduce the number of cases requiring invasive surgery.