Fat and neurosurgery: does obesity affect outcome after intracranial surgery?

Obesity has been linked to increased morbidity and mortality after some surgical procedures. The purpose of this study was to determine whether obesity affects outcome after general neurosurgery and subarachnoid hemorrhage (SAH).

Three data sets were analyzed, including a retrospective review of 404 patients undergoing cranial and spinal neurosurgical procedures, a prospective collection of 100 patients with aneurysmal SAH, and data from 3567 patients with aneurysmal SAH who were entered into randomized clinical trials of tirilazad. For each data set, outcome was assessed by mortality, postoperative morbidity, and Glasgow Outcome Scale score. Prognostic factors, including body weight and body mass index, were tested for their effect on these outcomes using multivariable logistic regression.

For patients undergoing general cranial and spinal neurosurgery, independent predictors of morbidity and mortality were age, American Society of Anesthesia class, disseminated malignancy, emergency surgery, and increased duration of surgery. For patients with SAH, score on the Glasgow Outcome Scale was associated with age and admission Glasgow Coma Scale score. In the tirilazad data set, multiple factors were associated with score on the Glasgow Outcome Scale, but, as with the other 2 data sets, body weight had no relationship to outcome.

Obesity may have less effect on the outcome of patients with mainly cranial neurosurgical disease and aneurysmal SAH than it does on patients undergoing other types of surgery.