[Report of an inquiry about epidural anesthesia for abdominal aortic aneurysm surgery in Japan].

BACKGROUND

Recently there are growing number of patients suffering from the abdominal aortic aneurysm (AAA), and we have many occasions to anesthetize these patients under coagulation therapy as well. Moreover, the risk of epidural hematoma increases when the operation of the AAA is performed with epidural technique because the operation is usually done with perioperative heparinization. For these reasons, we investigated the current situations of clinical practice in Japan in terms of the epidural anesthesia for AAA surgeries.

METHODS

The questionnaires were sent to all 998 Japanese Society of Anesthesiologists certified training hospitals in October 2005, anonymously asking about current practices concerning AAA cases, anesthetic managements, use of epidural anesthesia and the experience of any complications. Fifty one per cent of the total questionnaires were returned and 94% of them could be analyzed. Seventeen per cent of responders were from university institutes or university related hospitals and 75% of them were from general hospitals of secondary critical care centers.

RESULTS

This survey showed that the operations of AAA were done at 308 (64% of the responders) hospitals and the total number of AAA surgeries carried out was estimated to be 6,321 the last year. This figure was very close to the number announced by Japan Society of Cardiothoracic Surgeons. The epidural anesthesia was routinely used for AAA surgeries with general anesthesia in 224 hospitals (64%), but it was not used in 51 hospitals (14%). The standard protocol for the application of epidural anesthesia had been installed in 56% of hospitals and mostly in 187 hospitals (as several answers can be chosen). The epidural catheters were inserted the day before operation. There were 113 hospitals in which less than 2 hours was required from epidural puncture to heparinization, but in 141 hospitals it took more than 12 hours. However, on the contrary, many anesthetists answered that the risk of the epidural hematoma had been the cause of not routinely using the epidural anesthesia in AAA operations. We had 30 hospitals in which epidural hematoma had occurred in the cases not limited to AAA surgery and 17 cases of them resulted in severe complications afterwards.

CONCLUSIONS

This investigation clarified the current situations of the clinical practice in Japan of the use of epidural anesthesia for AAA surgeries.