Direct clipping of giant thrombosed basilar artery (BA) aneurysms continues to pose a formidable challenge in spite of the widespread use of skull base surgery technique. Recently, we employed deep hypothermic circulatory arrest for 2 cases of such complex BA aneurysms with the aid of cardiac surgeons and neuroanesthesiologists.
Canulation for cardiopulmonary bypass was performed centrally through the atrium in Case 1 (open chest technique) and peripherally through the femoral vein in Case 2 (closed chest technique). In both cases, giant thrombosed BA aneurysms were directly clipped without any new neurological deficits. The open chest method has several advantages such as rapid response to cardiac over-distension and ventricular fibrillation, and reduction of cooling and rewarming times. However, increased blood loss and post-operative pericardial and pleural effusion resulting from central canulation may occur. In this context, the simple closed chest technique is preferable unless the patient has severe aortic valve disease and significant organic dysfunction.
Heparin-coated equipment can be utilized to prevent serious hemorrhagic complications due to clotting defect. During circulatory arrest, the blood is not drained from the patient through the cardiopulmonary bypass because of the risk of air embolism and migration of intraluminal thrombus.Low-flow bypass is also preferred as an alternative to complete circulatory arrest for protection of the brain and other organs, and for identification of perforators around the aneurysm. Deep hypothermia with the option of circulatory arrest can be indispensable to the safe management of complex basilar artery aneurysms.
