Are the Calcium Antagonists Really Useful in Cerebral Aneurysmal Surgery? A Retrospective Study

In reply: We read with interest the comments by Dr. Mathiesen on our article, and we agree with him that it is difficult to avoid bias when selecting patients in a retrospective study.

To avoid the first bias pointed out by Dr. Mathiesen, as stated in our article, we reintroduced the patients who did not undergo neuropsychological evaluation (p. 32) and we did not find any statistical change in the results. It is obvious that if we reintroduced patients receiving CA for less than a week as patients treated by CA and as having 0% ischemia, the results would be changed. However, it was impossible for us to consider these patients in the CA group because most of them have simply received two tablets or perfusion of CA for 24 hours. Moreover, treatment was stopped for different reasons (frequently arterial hypotension) but never because the patient was doing well (of the 15 patients, 2 had a symptomatic ischemia, 6 were NPI, 5 were NPII, 4 were NPIII, and only 9 of 15 returned to work). Thus, we think Dr. Mathiesen has included bias favoring CA when recalculating the statistics in our publication.