[Role of anesthesiologist in endovascular management of intracranial aneurysms].

The aim is to give a review of the anesthesiological approach to neuroradiological endovascular treatment of intracranial aneurysm in Croatia since 2004, when the first procedure was done. It took place at University Department of Radiology, Zagreb University Hospital Center. The optimal conduct of anesthesia in the neuroradiology suite requires careful planning of each individual procedure. Essential components are detailed patient evaluation and due understanding of the underlying neuropathology. An open channel of communication between the radiologist and the anesthesiologist is important for routine care but is crucial in case of disasters that may occur during the procedure. In the patient management the basic principles of neuroanesthesia cannot be avoided. This includes optimization of CBF, perfusion pressure, control of intracranial pressure (ICP) and close monitoring of blood pressure (BP), fluid status and body temperature. The choice of anesthetic agents and techniques remains in the hands of the anesthesiologist. The needs of the neuroradiologist and the procedure have to be considered. Most institutions have their protocols and some favor conscious sedation whereas others prefer general anesthesia. There is little evidence in favor of either technique. The better image quality obtained from the motionless patient during digital subtraction angiography favors the use of general anesthesia over any other technique. Since the procedure is becoming very complex, the need for precise BP control and preparation for potential catastrophic complication are considerations for general anesthesia. Aneurysm rupture during endovascular procedures is not common but remains a potential risk. The incidence ranges from 2.3% to 3% and even higher in patients with already ruptured aneurysms. The mortality rate is up to 20% in case of rupture, especially if massive subarachnoid hemorrhage occurs. Anesthesiologic treatment depends on the severity of bleeding and includes maintaining CPP, lowering ICP, reversal of anticoagulation and patient transfer to the neurosurgical operating room if immediate ventriculostomy is needed. During a six month period, 55 patients underwent endovascular treatment of cerebral aneurysm at our hospital. They all were managed under general anesthesia. Since one of the critical roles of the anesthesiologist in the interventional radiology suite is to provide anticoagulation, the protocol of giving clopidogrel was followed, loading dose of 225 mg p. o. to each patient on the day of the procedure and immediately upon introducing microcatheter, heparin iv 70 IU/kg (average of 5000 IU), followed by boluses of 15 IU/kg (approx. 1000 IU) every 60 minutes. Activated clotting time was monitored for the effect of heparin. All patients except four were brought out of anesthesia at the table, immediately after the procedure for their neurological status to be assessed. None of the patients died during the procedure or within the first 24 hours. The mortality was up to 3.6% (two patients died on days 3 and 5 of the procedure). We had only one case of aneurysm rerupture during embolization with Guglielmi detachable coil, followed by cardiac arrest, but the patient (a 32-year-old woman) was resuscitated successfully and underwent standard neurosurgical procedure with full recovery in ICU after 14 days. There were 4 (7.2%) cases of vasospasm followed by ischemia, nimodipine treated, 2 with transient neurological dysfunction and another 2 with permanent hemianopsia. Interventional neuroradiology is rapidly and continually evolving, providing opportunities for the anesthesiologist to be part of this branch of medicine. It is essential to keep up-to-date in the knowledge of neuroanesthesia, neuropathology and interventional neuroradiology. In spite of the relatively non-invasive nature of the procedures, serious, even fatal complications may occur. Therefore, the role of anesthesiologist and his/her cooperation with neuroradiologist is crucial for successful results.