Impact of decompressive craniectomy on brain perfusion scintigraphy as an ancillary test for brain death diagnosis

Decompressive craniectomy is occasionally performed for patients with impending brain death, which is intended to relieve critically elevated intracranial pressure to keep effective intracranial perfusion. It has been in debate if this surgery later affects the result of brain perfusion scintigraphy performed as an ancillary test in the course of brain death diagnosis because rigid closed skull is deemed essential to elevate intracranial pressure to the point of total absence of intracranial radiotracer uptake on scintigraphy. The purpose of this study is to elucidate the impact of decompressive craniectomy on the result of brain perfusion scintigraphy in patients with suspected brain death.

This retrospective cross-sectional study included consecutive 151 brain perfusion scintigraphy performed in 138 patients with suspected brain death from various causes (male 82 patients, female 56 patients; range 0–74 years; mean age 36.6 years). All exams were indicated due to inconclusive clinical diagnosis of brain death. The scintigraphy protocol consists of immediate flow phase and delayed parenchymal phase planar imaging. Additional SPECT imaging was performed in 15 studies in 14 patients. The results, positive or negative brain flow, were compared between patients with and without decompressive craniectomy using Chi-squared test. As there were patients with repeat studies, analysis was performed for both initial and final exam results. Same dataset was used for initial and final exams in patients with only one exam.

In patients with suspected brain death, history of decompressive craniectomy does not affect the result of brain perfusion scintigraphy.