Anesthesia and anesthetic procedures for vascular malformations

Radiological interventional procedures, interventions/surgical operations have seen rapid advances in terms of invasiveness and complexity in recent years. At the same time, the spectrum of patients affected has expanded. Some patients have serious pre-existing conditions. Others are still very young (infants, toddlers) and at an age when sufficient cooperation for longer and more complex examinations or interventions cannot be expected. Many procedures are therefore inconceivable without general anesthesia or deep analgesia. Both are tasks of Anesthesiology.

Basically all anesthetic methods are available for anesthesiology support of interventional procedures in the treatment of vascular anomalies. Depending on the type and extent of the procedure, the comorbidities, the condition or the age of a patient, the spectrum ranges from analgesia to general anesthesia in combination with regional anesthesia. Local characteristics and habits also play an important role here. In each case the individual wishes of the patient must also be taken into account. Close interdisciplinary coordination should be practiced.

Regional anesthesia is nowadays established in many areas of surgical medicine. In certain cases, interventions on the extremities can also be performed with a regional procedure (e.g. axillary plexus block) or general anesthesia can be combined with it. In this procedure, a single bolus of anesthetic is injected directly into the vicinity of the afferent nerves of the affected extremity. This procedure is also called plexus anesthesia. The patient feels no pain during the procedure itself or for several hours afterwards.

In principle, catheter procedures are also conceivable and possible with regional anesthesia in individual cases. In addition to the bolus for the intervention itself, the patient is fitted with a small catheter close to the nerve for continuous infusion of analgesics or local anesthetics. Thus, it is possible to maintain analgesia for several days by continuous administration of a local anesthetic. However, this requires an inpatient procedure and corresponding strict supervision. This may be the case, for example, if pronounced post-interventional pain is to be expected or if a patient already has a known chronic pain syndrome. A catheter procedure can also be helpful in the case of early postoperative mobilization if it is foreseeable that mobilization is going to be very painful.

If general anesthesia is necessary in the course of a radiological intervention, this can of course be performed as part of an outpatient procedure. Close coordination between the attending radiologist and the anesthesiologist in advance is always desirable.

The following points should be clarified at an early stage:

• Which anesthetic procedure does the patient want or which interventional procedure is planned by the radiologist?
• Is the patient fit for anesthesia?
• Is the procedure to be performed on an outpatient basis?

The usual prerequisites apply (selection):

• The patient should be healthy and stable from the cardiopulmonary perspective, which is assessed anesthesiologically using the ASA physical status classification:
  • ASA 1: normal healthy patient
  • ASA 2: patient with mild systemic disease (e.g., well-controlled hypertension)
  • ASA 3: patient with severe systemic disease (e.g., coronary heart disease with stable situation)
  • ASA 4: patient with severe and life-threatening systemic disease (e.g., coronary heart disease with unstable situation)
  • ASA 5: moribund patient
• There must be no other serious underlying diseases (previous cardiac conditions) (no status > ASA 2).
• On the day of surgery, no vehicle driving is allowed post-interventionally because of the anesthesia.
• The patient must be fasting on the morning of the operation. The following limits apply:
  • > 6 h: last meal (adults and schoolchildren)
  • > 2 h: clear liquid without fat, carbonic acid, fruit juice, alcohol, coffee, etc.
  • > 4 h: last breastfeeding in infants and newborns
• In children, attention should be paid to premedication using midazolam juice and the application of EMLA® patches to the backs of the hand for local anesthesia, if ordered by the anesthesiologist. Both methods facilitate care of the child during the induction of anesthesia and during creation of a venous access.

There are two options for general anesthesia: so-called balanced anesthesia and total intravenous anesthesia (TIVA). Propofol is used for TIVA. This anesthetic has a favorable effect on postoperative nausea and vomiting and is therefore popular. In balanced anesthesia, propofol is used only for induction of anesthesia. Anesthesia is maintained with a gaseous (volatile) anesthetic. Today, sevoflurane and desflurane are most commonly used. Both substances are very controllable and ensure rapid awakening from anesthesia. In addition, the concentration in the breathing gas can be directly measured, which is a safety advantage. Nausea and vomiting are also rare in balanced anesthesia. In most cases, risk factors, such as motion sickness, can be identified in the premedication visit before anesthesia. In these cases, nausea and vomiting prophylaxis can be administered. Apart from very specific contraindications, the choice of anesthesia is left to the attending anesthesiologist and local habits. Both types of anesthesia are well established and are considered equally safe if the specific contraindications are observed.