What exactly are hemorrhoids?
Everyone has normal hemorrhoidal cushions—vascular tissue that helps seal the anal canal. Hemorrhoidal disease occurs when those cushions enlarge, become congested, bleed, prolapse, thrombose, or produce irritation and discomfort.
Internal hemorrhoids
Originate above the dentate line. They commonly cause bright-red bleeding and may prolapse, but uncomplicated internal hemorrhoids are often not painful.
External hemorrhoids
Arise below the dentate line and may cause itching, swelling, irritation, or acute pain when thrombosed. Embolization does not directly remove external hemorrhoidal tissue.
How internal hemorrhoids are graded
Why hemorrhoids bleed
Internal hemorrhoids have a rich arterial supply. Enlargement, mucosal trauma, prolapse, and elevated arterial inflow can produce recurrent bright-red bleeding. This vascular physiology is the rationale for hemorrhoidal artery embolization: instead of excising tissue, the procedure decreases abnormal arterial inflow to the hemorrhoidal plexus.
Symptoms need an accurate diagnosis
Hemorrhoids are enlarged vascular cushions in the anal canal. Symptoms can include painless bright-red bleeding, prolapse, irritation, mucus, itching, and discomfort. External thrombosis, fissure, malignancy, inflammatory bowel disease, and other anorectal conditions can produce overlapping symptoms, so evaluation should establish the correct diagnosis before treatment.
Evaluation before treatment
Rectal bleeding should not automatically be assumed to come from hemorrhoids. Depending on age, symptoms, anemia, bowel habits, prior colonoscopy, and examination findings, evaluation may include anoscopy, sigmoidoscopy, colonoscopy, or colorectal consultation.
Where embolization fits
Initial treatment often includes fiber, hydration, bowel-habit modification, and avoidance of straining. Office procedures such as rubber-band ligation, sclerotherapy, and infrared coagulation are widely used. Surgical options remain important for mixed, external, recurrent, or advanced prolapsing disease. Arterial embolization occupies a newer niche for selected patients—especially when bleeding is the dominant symptom or conventional surgery is undesirable.
Which symptoms are most likely to respond?
Embolization primarily treats the arterial component of internal hemorrhoidal disease. Bleeding-predominant internal hemorrhoids are therefore a particularly logical target. Large external hemorrhoids, skin tags, or substantial mechanical prolapse may remain after successful arterial treatment and can favor a different or combined strategy.
How the procedure works
Through a small arterial access site, an interventional radiologist navigates a catheter into branches of the inferior mesenteric and superior rectal arterial circulation. Angiography maps the arterial supply to the hemorrhoidal plexus. Target branches are then embolized—commonly with coils, particles, or a combination depending on anatomy and technique—to decrease pathologic arterial inflow.
What the evidence shows
A 2025 systematic review of 22 studies involving 810 procedures found high technical success and meaningful bleeding/symptom improvement in many patients, but also emphasized that available studies are heterogeneous and that high-quality comparative and long-term trials remain limited. That makes careful counseling particularly important.
Potential advantages and limitations
Because embolization does not excise anorectal tissue, recovery may be easier than surgical hemorrhoidectomy in selected patients. However, recurrence or incomplete symptom control can occur, particularly when collateral arterial supply persists. Embolization also does not directly correct large external hemorrhoids or substantial prolapse.
Risks
Reported adverse effects are usually transient but can include pelvic or rectal discomfort, nausea, fever, access-site complications, vascular injury, and nontarget embolization. Theoretical bowel or rectal ischemia is an important procedural consideration even though major ischemic complications have been uncommon in published series.
Procedure Video
See hemorrhoid artery embolization
Video demonstration of hemorrhoid artery embolization. Third-party educational video; technique and equipment vary.