Permanent postoperative anosmia: A serious complication of neurovascular decompression in the sitting position

In posterior fossa surgery, the sitting position offers a number of advanta ges believed to outweigh complications such as air embolism and pneumatocep halus. For this reason, the sitting position is frequently used in neurovas cular decompression for trigeminal neuralgia. Two years ago we reported on a previously undescribed complication: permanent postoperative anosmia. Fol lowing the recent occurrence of a second case, we conducted a nationwide su rvey to determine the frequency of this complication. Permanent postoperati ve anosmia following surgical procedures in the sitting position has been o bserved in 3 other institutions. In addition, the survey revealed that only 40% of German neurosurgeons still favor the sitting position for surgery o f the posterior cranial fossa. Considering that permanent anosmia severely reduces quality of life, and th at it can be avoided by using another position, the sitting position for su rgical procedures in the posterior fossa should be restricted to special ca ses (e.g., brain stem tumors).