What is an embolization?

What is an embolization?

Embolization describes the artificial blocking of a blood vessel. The related term embolism describes the displacement of material within the circulatory system. A well-known example of this is the pulmonary embolism. Depending on the size of the embolized material, blood vessels can become narrowed or completely blocked. The basic principle of this potentially dangerous process has been adapted by medical research to deliberately block blood vessels and therefore cut off targeted tissue from its blood supply.

This is achieved by the introduction of drugs, highly concentrated alcohol, vascular adhesives, or foreign materials (e.g., plastic or metal). In regular blood vessels, the corresponding tissue supplied by said blood vessel, no longer receives blood beyond the site of embolization. This causes the corresponding tissue e.g., a malignant tumor, to die. If this principle is applied in abnormal vascular connections or dilations, embolization helps to restore a healthy vascular flow.

When is embolization performed?

Some malignant tumors can be targeted by embolization. Embolization stops blood flow and therefore the supply of oxygen and nutrients to the tumor. The interrupted supply slows or completely stops the growth of cancer cells.

Pathological dilations of blood vessels (aneurysms) and vascular tangles (arteriovenous fistulas) can also be treated with embolization. The vascular walls at these dilated sites are thin and unstable, posing a high risk of wall rupture and bleeding. If an aneurysm or fistula ruptures in the brain, this can become a life-threatening medical emergency. 

The embolization procedure can also be used in acute emergencies, for example to treat haemorrhages following trauma. The primary goal is to minimize blood loss. A fine catheter is introduced into the bleeding vessel with a minimally invasive approach. Small metal coils are introduced through the catheter, which induce blood clotting and thereby stop the bleeding. This method is commonly used in pelvic fractures that are associated with major blood loss.

Common procedures

Prostate embolization

Benign prostatic hyperplasia (BPH) is an enlargement of the prostate. Older men are typically affected by this slowly progressive condition. Prostate embolization can be performed under local anaesthesia. A catheter is inserted, under X-ray guidance, into an artery in the groin, and slowly advanced to the prostate. Afterwards, embolic particles are injected to block the blood supply to the prostate.

Uterine fibroid embolization (UFE)

Uterine fibroids are benign, hormone-dependent tumours that arise from the uterine muscle layer. Depending on the size they may remain asymptomatic or cause symptoms such as heavy menstrual bleeding and painful periods. Embolization of fibroids can be an alternative to surgical removal. Special plastic microspheres are introduced into the artery supplying the fibroid through a catheter. Following embolization, the reduced blood supply causes the fibroid to shrink.

Tumor embolization

A tumor is an abnormal growth of a tissue due to uncontrolled cell proliferation. Tumors can be benign or malignant. In order to grow, they require a lot of oxygen and nutrients, that they receive through arterial blood vessels. Tumor embolization targets these blood vessels that supply the tumor by introducing embolic agents, chemotherapeutic drugs, or radioactive particles. 

Chemoembolization (TACE)

A special form of embolization can be performed in liver cancer or in the presence of liver metastases: transarterial chemoembolization (TACE). This is feasible as liver tumours receive most of the blood supply from the hepatic artery or its branches, while healthy liver tissue is supplied by the portal vein. During TACE, a cytotoxic drug is injected into the selected branch of the hepatic artery, followed by an embolic agent to block the artery. TACE can be used to shrink the tumor in size or serve as a bridge to surgery.

Aneurysm embolization 

Cerebral aneurysms can be treated using tiny platinum coils.  A catheter with a small platinum coil is inserted through the groin and advanced into the aneurysm. Once the catheter is at the target site, the platinum coils are released into the arterial bulge. These coils promote blood clotting and allow a natural sealing of the aneurysm.

Joint embolization

A relatively new approach is the occlusion of blood vessels of chronically inflamed joints by embolization. Chronic joint inflammation causes increased local blood flow in order to recruit immune cells. Embolization aims to stop this process of inflammation.

A thin catheter is inserted into the affected side branches of the supplying vessels. These are occluded by injecting small microspheres. Special care must be taken to preserve overall joint perfusion. Studies have shown promising outcomes with this method, particularly in cases of chronic knee inflammation.

What are the risks?

As with any medical procedure, complications may occur. Most complications arise due to the procedure itself. These include bleeding or infection at the side of catheter insertion, as well as allergic reactions to medical materials or medications.

Furthermore, embolic material may be displaced and migrate elsewhere, depriving healthy tissue of blood supply. For example, following prostate embolization, patients may experience haematuria and rectal bleeding. The prostate and other glands can become inflamed.

As the tissue dies, a process called tissue necrosis, can trigger the release of mediators that can lead to post-embolization syndrome. This occurs within 72 hours after the procedure and is characterised by nausea, malaise, abdominal pain, and a raised body temperature. As a treatment and prophylactic measure, pain medication and anti-emetics are administered before and during the procedure.

Due to continuous advances in embolization techniques in recent years, the side effects and complications have been significantly reduced and controlled.

What are the costs and is this covered by health insurance?

The costs of embolization can vary and depend on the specific procedure. For example, one session of chemo-embolization can cost around €3500. Reimbursement can be applied for and may be granted by insurance. However, statutory health insurers are not obliged to cover such procedures.

In contrast, prostate embolization for benign prostatic hyperplasia and uterine fibroid embolization are generally covered by statutory health insurance as they are included in the benefit catalogue.

It is advisable to clarify the costs of the planned procedure in advance and to obtain approval from the relevant health insurance provider beforehand.

Which physicians and clinics are specialists for embolization?

As embolization is a highly specialised interventional procedure, it is performed by specialists in interventional radiology and angiography. Depending on the target organ, other specialists may be consulted, such as gynaecologists, urologists, gastroenterologists, or neuroradiologists.

We would like to help patients find the most suitable specialist for their condition. Such procedures like embolization should only be performed by highly qualified specialists. All doctors listed here have been carefully vetted and selected.

They are recognised specialists in their respective fields and possess extensive experience in performing embolization procedures. We would like for you to benefit from the experience and arrange an initial consultation quickly and easily.