Principles of invasive therapy

Initially, the main goal is to relieve symptoms caused by the vascular anomaly and to avoid functional limitations and future complications. If conservative therapy alone is not successful, the choice of invasive therapy must always be weighed up between the expected benefits and success of the procedure and the possible risks and side effects of the procedure. The spectrum of different invasive therapy modalities is broad and requires a high degree of specialization. Interdisciplinary coordination is essential. Complete elimination or removal of a vascular anomaly is often not possible, but the symptoms or future complications can usually be alleviated or completely prevented.

Around the procedure

Before an invasive therapy is started, it should be determined whether the exact diagnosis of a vascular malformation is correct (ISSVA classification). Complex cases should therefore be discussed individually in an interdisciplinary conference. A combined approach using different procedures can also be coordinated in such a conference.

It is advisable to obtain patients’ commitment before and after a therapy via a special outpatient consultation service for vascular anomalies. Beforehand it is important to check whether all conservative therapy measures have been fully utilized.

Most interventions are plannable, elective procedures that also allow for a longer waiting period. In planning, the duration of the hospital stay and also the recovery phase after the intervention must be taken into account. In addition to the detailed informative, comprehensible patient interview about the meaning, alternatives (especially in comparison to other invasive procedures and purely conservative therapy), the procedure and risks of the intervention, a declaration of consent should be signed on the day before the intervention.

It should also be clarified in advance whether the intervention is to be performed under sedation or general anesthesia. In this case, coordination with the anesthesiologist during a premedication visit is essential, as additional examinations or precautions for anesthesia may become necessary.

It is important to understand that, given the extent of a vascular anomaly, a step-by-step approach with multiple procedures is often necessary. In most cases, the problem cannot be solved in a single procedure, as this would be too risky or have too many side effects. The optimal risk-benefit analysis for a single step in the procedure requires patience on the part of the patient (and parents) and the physician as well as an agreed therapy plan over a long period of time.


As a matter of principle, it must be clarified before every invasive therapy whether the spectrum of non-invasive therapy methods has already been fully exploited. Conservative therapy methods include, for example, drug therapy and compression therapy.

The multitude of possible minimally invasive and open surgical procedures as described here should be adapted to each patient with their specific constellation of findings. An interdisciplinary center that provides all the alternative therapeutic procedures offers advantages in terms of implementing the best therapeutic option for a patient and prevents the inappropriate selection of a single therapeutic procedure (according to Maslow’s motto: “if all you have is a hammer, everything looks like a nail”).


The range of possible complications extends from temporary symptoms to rare life-threatening clinical pictures, depending on the therapeutic procedure. The therapy-specific complications are presented in more detail in the following chapters.

One difference between the various invasive procedures is the actual invasiveness. Compared to open surgical procedures, interventional procedures such as sclerotherapy or embolization are minimally invasive. This means that the intervention is not performed via an open surgical access (e.g., skin incision), but via one or more small percutaneous accesses (using needles, guiding sheaths or catheters). Surrounding healthy structures are generally protected.

However, this does not mean that the complications with minimally invasive procedures are minimal. These procedures can also have serious, even life-threatening consequences.

The vascular malformation is usually not removed in the interventional procedures. Rather, the targeted interventional closure of the vascular malformation through hemodynamic and structural changes leads to a reduction of symptoms. Open surgery can in some cases eliminate the vascular anomaly completely, but it is often not feasible because of the extent of the anomaly, the risk of bleeding or for technical reasons. Open procedures are competently performed at interdisciplinary centers, and also require a high level of expertise and experience.

In general, the vast majority of interventions are performed as minimally invasive procedures at interdisciplinary centers, weighing up success, benefits, risks and side effects.