Dynamic Computed Tomography Angiography in Suspected Brain Death: A Noninvasive Biomarker

2014 ◽  
Vol 65 (4) ◽  
pp. 352-359 ◽  
Author(s):  
Santanu Chakraborty ◽  
Reem A. Adas
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Brain Death ◽  
Internal Carotid ◽  
External Carotid Artery ◽  
External Carotid ◽  
Ancillary Test ◽  
Organ Harvesting

Purpose Neurologic determination of death or brain death is primarily a clinical diagnosis. This must respect all guarantees required by law and should be determined early to avoid unnecessary treatment and allow organ harvesting for transplantation. Ancillary testing is used in situations in which clinical assessment is impossible or confounded by other factors. Our purpose is to determine the utility of dynamic computed tomographic angiography (dCTA) as an ancillary test for diagnosis of brain death. Materials and Methods We retrospectively reviewed 13 consecutive patients with suspected brain death in the intensive care unit who had dCTA. Contrast appearance timings recorded from the dCTA data were compared to findings from 15 controls selected from patients who presented with symptoms of acute stroke but showed no stroke in follow-up imaging. Results The dCTA allows us to reliably assess cerebral blood flow and to record time of individual cerebral vessels opacification. It also helps us to assess the intracranial flow qualitatively against the flow in extracranial vessels as a reference. We compared the time difference between enhancement of the external and internal carotid arteries and branches. In all patients who were brain dead, internal carotid artery enhancement was delayed, which occurred after external carotid artery branches were opacified. Conclusion In patients with suspected brain death, dCTA reliably demonstrated the lack of cerebral blood flow, with extracranial circulation as an internal reference. Our initial results suggest that inversion of time of contrast appearance between internal carotid artery and external carotid artery branches at the skull base could predict a lack of distal intracranial flow.

scholarly journals Effect of increases in cardiac contractility on cerebral blood flow in humans

2017 ◽  
Vol 313 (6) ◽  
pp. H1155-H1161 ◽  
Author(s):  
Shigehiko Ogoh ◽  
Gilbert Moralez ◽  
Takuro Washio ◽  
Satyam Sarma ◽  
Michinari Hieda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Cardiac Contractility ◽  
External Carotid Artery ◽  
External Carotid ◽  
High Dose ◽  
Artery Blood Flow

The effect of acute increases in cardiac contractility on cerebral blood flow (CBF) remains unknown. We hypothesized that the external carotid artery (ECA) downstream vasculature modifies the direct influence of acute increases in heart rate and cardiac function on CBF regulation. Twelve healthy subjects received two infusions of dobutamine [first a low dose (5 μg·kg−1·min−1) and then a high dose (15 μg·kg−1·min−1)] for 12 min each. Cardiac output, blood flow through the internal carotid artery (ICA) and ECA, and echocardiographic measurements were performed during dobutamine infusions. Despite increases in cardiac contractility, cardiac output, and arterial pressure with dobutamine, ICA blood flow and conductance slightly decreased from resting baseline during both low- and high-dose infusions. In contrast, ECA blood flow and conductance increased appreciably during both low- and high-dose infusions. Greater ECA vascular conductance and corresponding increases in blood flow may protect overperfusion of intracranial cerebral arteries during enhanced cardiac contractility and associated increases in cardiac output and perfusion pressure. Importantly, these findings suggest that the acute increase of blood perfusion attributable to dobutamine administration does not cause cerebral overperfusion or an associated risk of cerebral vascular damage. NEW & NOTEWORTHY A dobutamine-induced increase in cardiac contractility did not increase internal carotid artery blood flow despite an increase in cardiac output and arterial blood pressure. In contrast, external carotid artery blood flow and conductance increased. This external cerebral blood flow response may assist with protecting from overperfusion of intracranial blood flow.

scholarly journals The Effects of Serotonin on Local Cerebral Blood Flow

1983 ◽  
Vol 3 (1) ◽  
pp. 71-77 ◽  
Author(s):  
J. J. Grome ◽  
A. M. Harper
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Regional Blood Flow ◽  
Physiological Saline ◽  
External Carotid ◽  
Local Cerebral Blood Flow ◽  
Autoradiographic Technique

This study was undertaken to measure the effects of serotonin administration on local cerebral blood flow following blood–brain barrier (BBB) disruption with hypertonic urea. Rats were anesthetized with halothane in nitrous oxide and oxygen (70%:30%). In some animals urea (3.5 M) was infused retrogradely through an external carotid catheter, followed after 10 min by serotonin (50 ng kg−1 min−1) or physiological saline. Local cerebral blood flow was measured using the 14C-iodoantipyrine quantitative autoradiographic technique of Sakurada et al. (1978). The administration of saline or urea alone had only minimal effects on local cerebral blood flow. When the BBB was intact, serotonin produced a significant fall in regional blood flow only in the caudate nucleus. Following BBB disruption, however, serotonin produced a marked decrease in local perfusion in a number of discrete brain areas that are supplied by blood from the internal carotid artery. On the other hand, there were increases in local perfusion in areas not supplied by the internal carotid artery.

Impact of transient hypotension on regional cerebral blood flow in humans

2015 ◽  
Vol 129 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Nia C.S. Lewis ◽  
Kurt J. Smith ◽  
Anthony R. Bain ◽  
Kevin W. Wildfong ◽  
Tianne Numan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Vertebral Artery ◽  
Regional Cerebral Blood Flow ◽  
Internal Carotid ◽  
Regional Cerebral Blood

Diameter reductions in the internal carotid artery (ICA) and vertebral artery (VA) contribute to the decline in brain blood with hypotension. The decline in vertebral blood flow with hypotension was greater when carbon dioxide was low; this was not apparent in the ICA.

Retromandibular Fossa Approach to the High Cervical Internal Carotid Artery: An Anatomic Study

2008 ◽  
Vol 62 (suppl_5) ◽  
pp. ONS363-ONS370 ◽  
Author(s):  
Yusuf Izci ◽  
Roham Moftakhar ◽  
Mark Pyle ◽  
Mustafa K. Basşkaya
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Average Length ◽  
Cranial Nerves ◽  
External Carotid Artery ◽  
External Carotid ◽  
Digastric Muscle ◽  
High Cervical ◽  
Cervical Internal Carotid Artery

Abstract Objective: Access to the high cervical internal carotid artery (ICA) is technically challenging for the treatment of lesions in and around this region. The aims of this study were to analyze the efficacy of approaching the high cervical ICA through the retromandibular fossa and to compare preauricular and postauricular incisions. In addition, the relevant neural and vascular structures of this region are demonstrated in cadaveric dissections. Methods: The retromandibular fossa approach was performed in four arterial and venous latex-injected cadaveric heads and necks (eight sides) via preauricular and postauricular incisions. This approach included three steps: 1) sternocleidomastoid muscle dissection; 2) transparotid dissection; and 3) removal of the styloid apparatus and opening of the retromandibular fossa to expose the cervical ICA with the internal jugular vein along with Cranial Nerves X, XI, and XII. Results: The posterior belly of the digastric muscle and the styloid muscles were the main obstacles to reaching the high cervical ICA. The high cervical ICA was successfully exposed through the retromandibular fossa in all specimens. In all specimens, the cervical ICA exhibited an S-shaped curve in the retromandibular fossa. The external carotid artery was located more superficially than the ICA in all specimens. The average length of the ICA in the retromandibular fossa was 6.8 cm. Conclusion: The entire cervical ICA can be exposed via the retromandibular fossa approach without neural and vascular injury by use of meticulous dissection and good anatomic knowledge. Mandibulotomy is not necessary for adequate visualization of the high cervical ICA.

Clinical Utility of Quantitative Cerebral Blood Flow Measurements during Internal Carotid Artery Test Occlusions

Neurosurgery ◽  
2002 ◽  
Vol 50 (5) ◽  
pp. 996-1005 ◽  
Author(s):  
Randolph S. Marshall ◽  
Ronald M. Lazar ◽  
William L. Young ◽  
Robert A. Solomon ◽  
Shailendra Joshi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Clinical Utility ◽  
Internal Carotid ◽  
Flow Measurements ◽  
Blood Flow Measurements

scholarly journals Cerebral Blood Flow and Metabolism Measurement Using Positron Emission Tomography before and during Internal Carotid Artery Test Occlusions: Feasibility of Rapid Quantitative Measurement of CBF and OEF/CMRO2

2012 ◽  
Vol 18 (3) ◽  
pp. 264-274 ◽  
Author(s):  
N. Kawai ◽  
M. Kawanishi ◽  
A. Shindou ◽  
N. Kudomi ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
False Negative ◽  
Photon Emission ◽  
Emission Tomography ◽  
Positron Emission

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study is a sensitive test for predicting the outcome of permanent ICA occlusion. However, false negative results sometimes occur using single photon emission tomography (SPECT). We have recently developed a rapid positron emission tomography (PET) protocol that measures not only the CBF but also the cerebral oxygen metabolism before and during BTO in succession. We measured acute changes in regional CBF and OEF/CMRO2 before and during BTO in three cases with large or giant cerebral aneurysms using the rapid PET protocol. Although no patients showed ischemic symptoms during BTO, PET studies exhibited mildly to moderately decreased CBF (9∼34%) compared to the values obtained before BTO in all cases. The average OEF during BTO was significantly increased (21% and 43%) than that of before BTO in two cases. The two cases were considered to be non-tolerant for permanent ICA occlusion and treated without ICA sacrifice. Measurement of the CBF and OEF/CMRO2 using a rapid PET protocol before and during BTO is feasible and can be used for accurate assessment of tolerance prediction in ICA occlusion.

Assessing the Effects of Antihypertensive Medication on Cerebral Blood Flow: Demonstration in Internal Carotid Artery Occlusion

DICP ◽  
1991 ◽  
Vol 25 (12) ◽  
pp. 1299-1301 ◽  
Author(s):  
Susan C. Fagan ◽  
James R. Ewing ◽  
Steven R. Levine ◽  
Gretchen E. Tietjen ◽  
Nabih M. Ramadan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Antihypertensive Medication ◽  
Internal Carotid ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Internal Carotid Artery Occlusion ◽  
Bilateral Carotid

Dynamic cerebral blood flow (CBF) studies using acetazolamide or hypercapnia as a vasodilatory challenge have attempted to evaluate intracranial hemodynamics. We report two patients with asymptomatic internal carotid artery occlusion in whom the vasodilatory stimulus was a single oral dose of antihypertensive medication (prazosin hydrochloride or enalapril maléate). In both patients, changes in regional CBF occurred that were larger than those seen in nine normal controls. One patient experienced an improvement in regional CBF with a reduction in probe pair asymmetry. In the other patient, who had bilateral carotid artery disease, a decrease in regional CBF in all 16 probes (mean decrease 12 percent) and an accentuation of the predose asymmetry were observed. Both patients remained asymptomatic throughout the study. Assessing these effects on cerebral circulation may help identify patients at risk for iatrogenic focal cerebral ischemia and provide information regarding the functional status of the cerebral vasculature.

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