Rectal artery embolization: recent advances and research progress

Rectal artery embolization (RAE), or the Emborrhoid technique, is a new minimally invasive treatment for bleeding internal hemorrhoids. This review examines vessel selection, embolic materials, procedural success, recurrence, and safety. Technical success involves successful catheterization and occlusion of target arteries, while clinical success means symptom improvement without further treatment. Studies show consistently high technical success but variable clinical success. One meta-analysis found mean technical and clinical success rates of 97.8% and 78.9%, respectively, while another reported pooled estimates of 99% and 82%. Definitions, sample sizes, and follow-up vary across studies. In an 80-patient study, 68.7% had no rectal bleeding after 12 months, while 31.3% experienced recurrence, and 21.3% needed repeat embolization. A separate study with 42 patients showed 93% success but a 54% rate of minor mucosal injury. Current evidence favors superselective superior rectal artery embolization as the primary approach, with selective assessment of middle rectal artery inflow. There's insufficient evidence to broadly recommend large microspheres and liquid agents. Standardized outcomes, clear denominators, and longer follow-up are needed.