2000 Volume 28 Issue 4 Pages 260-266
Hypothermic anesthesia (HTA) in aneurysmal surgery is a useful and effective tool for preventing possible ischemic or mechanical damage to the brain caused by surgical manipulations. From the viewpoint of clinical use, HTA can be divided into three groups: mild HTA (35-33°C), moderate HTA (33-27°C) and deep HTA (20°C-). We have been using moderate HTA in surgery for formidable aneurysms since 1980. The recent anesthesiological advances in this field enabled us to use mild HTA for a wider range of cases with subarachnoid hemorrhage and deep HTA for restricted cases. During the last 7 years, 282 aneurysmal surgeries were carried out and 166 (58.9%) were under HTA. The use of HTA significantly increased in the last 3 ('96-'98) of these 7 years: 66.4% vs. 54%, P<0.05.
From the review of our own experiences in HTA, we recommend the expanded utilization of HTA for aneurysmal surgery with satisfactory safety. To minimize damage to the brain tissue in cases with considerable surgical insults expected, mild HTA is a tool of choice. The use of HTA is also indicated for operations for multiple or bilaterally located aneurysms or for cases with tight brain caused by the existence of intracerebral hematoma or brain edema at the acute stage. Furthermore, mild HTA may well be used in every early surgery because of its clinical safety and ease of use. Moderate HTA, requiring more complicated techniques and assistance of experienced anesthesiologists, brings further increased tolerance to ischemic insults to the brain. Cases with supratentorial large or giant aneurysm or with internal carotid aneurysm, which are difficult to clip for a long without time without causing parent artery occlusion are good candidates for moderate HTA as well as those with basilar trunk aneurysm. Techniques of PCPS allow us to use deep HTA, which is less invasive than the open-chest method, and we can adopt this tool for extremely difficult operations like clipping of deeply seated giant or complicated and posing aneurysm such as the two cases presented in this report.
