Selective 4 Vessels Angiography in Brain Death: A Retrospective Study

Abstract

492In Canada, neurologic determination of death (NDD) or brain death (BD) diagnosis is based on five clinicals criteria: established etiology capable of causing NDD, deep unresponsive coma, absent brainstem reflexes, absent breathing reflex and absent confounding factors. 1 However, ancillary tests are sometimes necessary when the clinical exam cannot be completely performed or when confounding factors are present. Recently, a Canadian workforce of experts in brain death and organ donation published guidelines on the use of ancillary tests for NDD. 2 Among their recommendations, they stated that "Absence of brain blood flow is the imaging and physiological correlate of brain arrest and brain death. From an imaging point of view, brain blood flow refers to intra-arterial filling and the ABSTRACT: Background: In Canada, ancillary tests, such as selective four vessels angiography (S4VA), are sometimes necessary for brain death (BD) diagnosis when the clinical exam cannot be completed or confounding factors are present. Recent Canadian guidelines assert that brain death is supported by the absence of arterial blood flow at the surface of the brain and that venous return should not be considered. However, neuropathologic and angiographic studies have suggested that arteries might still be patent in BD patients. Current clinical practices in BD diagnosis following S4VA need to be better understood. Methods: We conducted a retrospective study of all S4VA performed for the determination of BD in a level 1 NeuroTrauma centre from 2003 to 2007. The objective of the study was to describe the prevalence of intracranial arterial, capillary (parenchymogram) and venous opacification in our study population. All tests were reviewed independently by two neuroradiologists. Disagreements were resolved by consensus. Results: Thirty two patients were declared BD following S4VA during the study period. Nine of these patients (28%) presented some proximal opacification of intracranial arteries (95% CI 15-45%). As opposed, none had a cerebral capillary and deep venous drainage opacification (95% CI 0-10%). Conclusion: The absence of cerebral deep venous drainage or parenchymogram might represent a better objective marker of cerebral circulatory arrest for brain death diagnosis when the use of S4VA is required. These findings open the path for further research in enhancing our interpretation of angiographic studies for brain death diagnosis.RÉSUMÉ: Étude rétrospective de l'angiographie sélective des 4 vaisseaux pour le diagnostic de la mort cérébrale. Contexte : Au Canada, des tests complémentaires tels l'angiographie sélective des 4 vaisseaux (AS4V) sont parfois nécessaires pour poser le diagnostic de mort cérébrale (MC) quand l'examen clinique est impossible ou lorsque des facteurs confondants sont présents. Selon des lignes directrices canadiennes récentes, la mort cérébrale est confirmée par l'absence de flux sanguin artériel à la surface du cerveau sans tenir compte du retour veineux. Cependant, des études neuropathologiques et ang...

Dynamic evaluation of stasis filling phenomenon with computed tomography in diagnosis of brain death

“…This phenomenon is commonly observed in angiographic studies. Munari et al reported stasis filling in 5 % (one out of 20), Braun et al in 11 % (15/140), Bradac et al in 12.5 % (two out of 16), Kricheff et al in 15 % (three out of 20), and Savard et al in 28 % (nine out of 32) of cases [2, 6–9]. CTA studies reveal even higher prevalence of intracranial filling.…”

Ancillary Testing in Brain Death

“…21 Inability to perform an apnea test is uncommon in some series of consecutive patients, but existing data, all from single centers, are somewhat conflicting. 22,23 Differences between centers can likely be explained by multiple factors, including patient characteristics within a particular intensive care unit, typical time lags before patients are assessed for brain death, and individual physician preferences. The degree of hypoxemia and the presence of metabolic acidosis are recognized predictors of inability to complete an apnea test.…”

Brain Death Guidelines Explained

“…These spinal responses include brief, slow movements in the upper limbs, flexion in the fingers, fine finger tremors, 17 or arm lifting; and they do not become integrated into truly coordinated decerebrate or decorticate responses. [18][19][20][21][22] They extinguish with repeated stimulation. Ocular "micro tremors" and eyelid opening have been incidentally noted.…”