Provocative Mesenteric Angiography: Safety and Efficacy in Occult GI Bleeding

Provocative Mesenteric Angiography: Safety and Efficacy in Occult GI Bleeding

This episode tackles one of the most frustrating clinical challenges in Interventional Radiology: the patient with a recurrent occult GI bleed who has failed endoscopy and standard imaging. We analyze the largest retrospective cohort study to date (22 years of data) on TPA-based Provocative Mesenteric Angiography (PMA) to determine when to use this aggressive diagnostic maneuver.

• The Safety Surprise: Despite intentionally provoking bleeding with TPA and Nitroglycerin, the study revealed zero major bleeding adverse events, thanks to "first-pass hepatic metabolism" clearing the drugs before they hit the systemic circulation.

• The "Secret Sauce" for Selection: We identify the two independent predictors that increase the odds of a positive study by nearly sevenfold:

  • Hematochezia (bright red/maroon stool).

  • A Prior Positive Radiologic Study (CTA or Tagged RBC), even if the bleed appeared to stop.

• The Hard Stop: The data provides a clear exclusion criterion: zero patients with Melena (black tarry stool) and negative prior imaging had a positive PMA result, suggesting these procedures are likely futile.

• Technical Mastery: Success relies on super-selectivity. Injecting from a distal, third-order vessel yielded a 63.6% positivity rate, compared to just 21.5% from a proximal injection.

Tune in to learn how to safely provoke the bleed on your terms and identify the source when all other methods fail.

Based on comments from experts, content on Wysdom, and the article cited below.

Benvenuti TA, Chisholm M, Cline B, et al. Provocative Mesenteric Angiography for Obscure Gastrointestinal Hemorrhage: An Update on Outcomes, Safety, and Predictors of Success. J Vasc Interv Radiol. 2025;36(10):1558-1566. doi:10.1016/j.jvir.2025.06.022