Outcome following posterior fossa craniectomy in patients in the sitting or horizontal positions.

Controversy continues to surround the use of the sitting position for neurosurgical procedures. This retrospective review of 579 posterior fossa craniectomies performed over a 4-yr period from 1981 through 1984 examines outcome following these procedures performed with the patients in either the sitting (n = 333) or horizontal (supine, prone, lateral, park bench) (n = 246) position. Multiple preoperative, intraoperative, and postoperative variables were analyzed. Venous air embolism occurred significantly more often in patients in the sitting position (45% versus 12%). However, no morbidity or mortality was attributed to venous air embolism. The incidence of hypotension with positioning was not different by position (19% in the sitting patients and 24% in the horizontal patients). Average blood replacement was significantly lower in the sitting patients (359 ml versus 507 ml), and the incidence of transfusion of greater than two units of blood was significantly higher in the horizontal patients (13% versus 3%). Postoperative cranial nerve function was significantly better in patients in the sitting group as compared to those in the horizontal group. The incidence of perioperative cardiopulmonary complications was not different between groups. These outcome data suggest that there are potential advantages and disadvantages of both the sitting and horizontal positions without supporting a significantly increased morbidity or mortality associated with either position.