Real-time detection of vascular occlusion and reperfusion of the brain during surgery by using infrared imaging

2002 ◽  
Vol 96 (5) ◽  
pp. 918-923 ◽  
Author(s):  
Joseph C. Watson ◽  
Alexander M. Gorbach ◽  
Ryszard M. Pluta ◽  
Ramin Rak ◽  
John D. Heiss ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Resolution ◽  
Real Time ◽  
Infrared Imaging ◽  
Cerebral Arteries ◽  
Infrared Camera ◽  
Collateral Flow ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Application of sensitive infrared imaging is ideally suited to observe blood vessels and blood flow in exposed organs, including the brain. Temporary vascular occlusion is an important part of neurosurgery, but the capacity to monitor the effects of these occlusions in real time is limited. In surgical procedures that require vascular manipulation, such as those involving aneurysms, arteriovenous malformations (AVMs), or tumors, the ability to visualize blood flow in vessels and their distribution beds would be beneficial. The authors recount their experience in the use of a sensitive (0.02°C), high-resolution (up to 50 µm/pixel) infrared camera with a rapid shutter speed (up to 2 msec/frame) for localizing cortical function intraoperatively. They observed high-resolution images of cerebral arteries and veins. The authors hypothesized that infrared imaging of cerebral arteries, performed using a sensitive, high-resolution camera during surgery, would permit changes in arterial flow to be be seen immediately, thus providing real-time assessment of brain perfusion in the involved vascular territory. Methods. Cynomolgus monkeys underwent extensive craniectomies, exposing the frontal, parietal, and temporal lobes. Temporary occlusions of the internal carotid artery and middle cerebral artery branches (30 events) were performed serially and were visualized with the aid of an infrared camera. Arteries and veins of the monkey brain were clearly visualized due to cooling of the exposed brain, which contrasted with blood within the vessels that remained at core temperature. Blood flow changes in vessels were seen immediately (< 1 second) in real time during occlusion and reopening of the vessels, regardless of the duration of the occlusion. Areas of decreased cortical blood flow rapidly cooled (−0.3 to 1.3°C) and reheated in response to reperfusion. Rewarming occurred faster in arteries than in the cortex (for a 20-minute occlusion, the change in temperature per second was 2 × 10−2°C in the artery and 7 × 10−3°C in the brain). Collateral flow could be evaluated by intraoperative observations and data processing. Conclusions. Use of high-resolution, digital infrared imaging permits real-time visualization of arterial flow. It has the potential to provide the surgeon with a means to assess collateral flow during temporary vessel occlusion and to visualize directly the flow in parent arteries or persistent filling of an aneurysm after clipping. During surgery for AVMs, the technique may provide a new way to assess arterial inflow, venous outflow, results of embolization, collateral flow, steal, and normal perfusion pressure breakthrough.

Vision of the future: initial experience with intraoperative real-time high-resolution dynamic infrared imaging

2002 ◽  
Vol 97 (6) ◽  
pp. 1460-1471 ◽  
Author(s):  
Robert D. Ecker ◽  
Stephan J. Goerss ◽  
Fredric B. Meyer ◽  
Aaron A. Cohen-Gadol ◽  
Jeffrey W. Britton ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Infrared Imaging ◽  
Intraoperative Imaging ◽  
Initial Experience ◽  
Cerebral Vessel ◽  
Content Type ◽  
Bypass Patency ◽  
Neurosurgical Patients ◽  
Fine Print

✓ High-resolution dynamic infrared (DIR) imaging provides intraoperative real-time physiological, anatomical, and pathological information; however, DIR imaging has rarely been used in neurosurgical patients. The authors report on their initial experience with intraoperative DIR imaging in 30 such patients. A novel, long-wave (8–10 µm), narrow-band, focal-plane-array infrared photodetector was incorporated into a camera system with a temperature resolution of 0.006°C, providing 65,000 pixels/frame at a data acquisition rate of 200 frames/second. Intraoperative imaging of patients was performed before and after surgery. Infrared data were subsequently analyzed by examining absolute differences in cortical temperatures, changes in temperature over time, and infrared intensities at varying physiological frequencies. Dynamic infrared imaging was applied in a variety of neurosurgical cases. After resection of an arteriovenous malformation, there was postoperative hyperperfusion of the surrounding brain parenchyma, which was consistent with a loss of autoregulation. Bypass patency and increased perfusion of adjacent brain were documented during two of three extracranial—intracranial bypasses. In seven of nine patients with epilepsy the results of DIR imaging corresponded to seizure foci that had been electrocorticographically mapped preoperatively. Dynamic infrared imaging demonstrated the functional cortex in four of nine patients undergoing awake resection and cortical stimulation. Finally, DIR imaging exhibited the distinct thermal footprints of 14 of 16 brain tumors. Dynamic infrared imaging may prove to be a powerful adjunctive intraoperative diagnostic tool in the neurosurgical imaging armamentarium. Real-time assessment of cerebral vessel patency and cerebral perfusion are the most direct applications of this technology. Uses of this imaging modality in the localization of epileptic foci, identification of functional cortex during awake craniotomy, and determination of tumor border and intraoperative brain shift are avenues of inquiry that require further investigation.

Microregional blood flow changes in experimental cerebral ischemia

1971 ◽  
Vol 35 (2) ◽  
pp. 155-166 ◽  
Author(s):  
Y. Lucas Yamamoto ◽  
Kathryne M. Phillips ◽  
Charles P. Hodge ◽  
William Feindel
Keyword(s):  
Blood Flow ◽  
Cerebral Ischemia ◽  
Fluorescein Angiography ◽  
Focal Cerebral Ischemia ◽  
Gamma Activity ◽  
Collateral Flow ◽  
Silicon Detectors ◽  
Content Type ◽  
Perfusion Flow ◽  
The Brain

✓ A branch of the middle cerebral artery on the convexity of the dog brain was occluded to produce an area of focal cerebral ischemia which could then be defined by fluorescein angiography of the brain. Repeated fluorescein angiography and measurement of microregional cerebral blood flow by xenon133 injected into the carotid artery and monitored by miniature lithium-drifted silicon detectors for gamma activity demonstrated that the ischemic zone was reduced in size by better collateral flow when the animals were allowed to breathe 5% carbon dioxide and 95% oxygen. Conversely, hyperventilation reducing the pCO2 made the ischemic zone larger by reducing collateral flow. No evidence was found to indicate that hypercapnia preferentially deprived the ischemic zone of perfusion flow. Retrograde collateral flow in the surface arteries appeared effective in terms of microcirculatory perfusion.

Subarachnoid hemorrhage—induced upregulation of the 5-HT1B receptor in cerebral arteries in rats

2003 ◽  
Vol 99 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Jacob Hansen-Schwartz ◽  
Natalie Løvland Hoel ◽  
Cang-Bao Xu ◽  
Niels-Aage Svendgaard ◽  
Lars Edvinsson
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Real Time ◽  
Cerebral Vasospasm ◽  
Cerebral Arteries ◽  
Specific Treatment ◽  
Content Type ◽  
Sequence Of Events ◽  
Arterial Blood ◽  
Receptor Phenotype ◽  
Fine Print

Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture—induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH. Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription—polymerase chain reaction (PCR). In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed. Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.

Neuronal damage in gerbils caused by intermittent forebrain ischemia

1999 ◽  
Vol 91 (5) ◽  
pp. 835-842 ◽  
Author(s):  
Takatoshi Sorimachi ◽  
Hiroshi Abe ◽  
Shigekazu Takeuchi ◽  
Ryuichi Tanaka
Keyword(s):  
Neuronal Damage ◽  
Cerebral Arteries ◽  
Ischemic Insult ◽  
Content Type ◽  
Ischemic Episode ◽  
Temporary Occlusion ◽  
Ischemic Depolarization ◽  
The Brain ◽  
Severe Ischemia ◽  
Fine Print

Object. The purpose of this study was to investigate the possibility of preventing cumulative neuronal damage after repetitive severe ischemia.Methods. The authors monitored ischemic depolarization in the gerbil hippocampus, which has recently been shown to be a good experimental model of the effects of brief ischemia on the brain, and evaluated neuronal damage in the CA1 subregion 7 days after the ischemic insult. In a single-ischemia paradigm, the results indicate that induction of ischemia-induced neuronal damage depended on the duration of ischemic depolarization. Neuronal damage can be detected in the CA1 subregion after a period of depolarization lasting 210 seconds. Using a double-ischemia paradigm in which the animals were subjected to two periods of ischemia, there was apparently no accumulation of neuronal damage from the first ischemic episode to the second, provided the duration of the first period of ischemic depolarization did not exceed 90 seconds. Neuronal damage accumulated when the duration of the first ischemia episode exceeded 90 seconds, regardless of the duration of the reperfusion interval between the two ischemic insults. Finally, when the ischemic insult was spread over four separate episodes, each lasting 90 seconds (with a reperfusion interval of 5 minutes), neuronal damage was not found when the total depolarization period was less than 420 seconds.Conclusions. The authors conclude that cumulative neuronal damage may be avoided by adopting an intermittent ischemia approach. The implications of these results for human surgery requiring temporary occlusion of the cerebral arteries are discussed.

Asymmetry of pressure autoregulation after traumatic brain injury

2003 ◽  
Vol 99 (6) ◽  
pp. 991-998 ◽  
Author(s):  
Eric A. Schmidt ◽  
Marek Czosnyka ◽  
Luzius A. Steiner ◽  
Marcella Balestreri ◽  
Piotr Smielewski ◽  
...  
Keyword(s):  
Head Injuries ◽  
Cerebral Arteries ◽  
Brain Lesion ◽  
Fatal Outcome ◽  
Midline Shift ◽  
Content Type ◽  
Arterial Blood ◽  
Left And Right ◽  
The Brain ◽  
Fine Print

Object. The aim of this study was to assess the asymmetry of autoregulation between the left and right sides of the brain by using bilateral transcranial Doppler ultrasonography in a cohort of patients with head injuries. Methods. Ninety-six patients with head injuries comprised the study population. All significant intracranial mass lesions were promptly removed. The patients were given medications to induce sedation and paralysis, and artificial ventilation. Arterial blood pressure (ABP) and intracranial pressure (ICP) were monitored in an invasive manner. A strategy based on the patient's cerebral perfusion pressure (CPP = ABP − ICP) was applied: CPP was maintained at a level higher than 70 mm Hg and ICP at a level lower than 25 mm Hg. The left and right middle cerebral arteries were insonated daily, and bilateral flow velocities (FVs) were recorded. The correlation coefficient between the CPP and FV, termed Mx, was calculated and time-averaged over each recording period on both sides. An Mx close to 1 signified that slow fluctuations in CPP produced synchronized slow changes in FV, indicating a defective autoregulation. An Mx close to 0 indicated preserved autoregulation. Computerized tomography scans in all patients were reviewed; the side on which the major brain lesion was located was noted and the extent of the midline shift was determined. Outcome was measured 6 months after discharge. The left—right difference in the Mx between the hemispheres was significantly higher in patients who died than in those who survived (0.16 ± 0.04 compared with 0.08 ± 0.01; p = 0.04). The left—right difference in the Mx was correlated with a midline shift (r = −0.42; p = 0.03). Autoregulation was worse on the side of the brain where the lesion was located (p < 0.035). Conclusions. The left—right difference in autoregulation is significantly associated with a fatal outcome. Autoregulation in the brain is worse on the side ipsilateral to the lesion and on the side of expansion in cases in which there is a midline shift.

Cerebral and systemic circulatory effects of arterial hypotension induced by adenosine

1983 ◽  
Vol 58 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Neal F. Kassell ◽  
David J. Boarini ◽  
Julie J. Olin ◽  
James A. Sprowell
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Hypotensive Effect ◽  
Arterial Hypotension ◽  
Content Type ◽  
Circulatory Effects ◽  
Rebound Hypertension ◽  
Neurosurgical Patients ◽  
The Brain ◽  
Fine Print

✓ In six dogs anesthetized with halothane and nitrous oxide, mean arterial pressure (MAP) was lowered to 40 mm Hg for an average of 90 minutes by intravenous infusion of adenosine. The hypotensive effect of the adenosine was potentiated by administering dipyridamole to block its intravascular inactivation. Blood flow to the brain, spinal cord, heart, kidneys, and skeletal muscle was measured six times in each animal using the radioactive microsphere technique. Determinations were made before, during, and 30 minutes after the hypotensive period. During the hypotensive period, MAP was decreased 61% and was related to a proportional decrease in peripheral vascular resistance. Cardiac index decreased 14%. Total cerebral blood flow (CBF) decreased an average of 28% and cerebral vascular resistance decreased 53%. The reduction in CBF was heterogeneous; the cerebral cortex and corpus callosum were most affected and the brain stem least affected. No change occurred in the cerebral metabolic rate of oxygen usage (CMRO2). Left ventricle flow increased 147% and right ventricle flow increased 271%. Blood flow to the kidneys decreased 70%, and to the liver decreased to 6% of control. Jejunum blood flow increased 138% during recovery, while stomach flow varied but showed no statistical change. There was no tachyphylaxis, rebound hypertension, or toxicity associated with the adenosine-induced hypotension. These properties suggest that adenosine may be a useful agent for inducing arterial hypotension in neurosurgical patients.

An Experimental Study of the Effects Anatomical Variations Have on Collateral Flows Within the Circle of Willis

2011 ◽  
Author(s):  
Paul Fahy ◽  
Patrick Delassus ◽  
Padraig O’Flynn ◽  
Liam Morris
Keyword(s):  
Experimental Study ◽  
Blood Flow ◽  
Cerebral Arteries ◽  
Anatomical Variations ◽  
Flow Patterns ◽  
Circle Of Willis ◽  
Collateral Flow ◽  
Arterial Network ◽  
Flow Feature ◽  
The Brain

The circle of Willis (CoW) is a complex arterial network comprising of major cerebral arteries that converge to form a pentagonal arrangement as shown in Figure 1(A). This arterial network supplies oxygen-enriched blood to the brain. An incomplete CoW can exist in up to 50% of cases [1]. These missing vessels can be accommodated by the collateral flow feature within the CoW configuration. In certain circumstances, anatomical variations within the CoW can result in undesirable flow patterns [2–3]. It is unclear from the literature what effects these variations can have on blood flow collision paths within a complete CoW.

Cerebral aneurysms following radiotherapy for medulloblastoma

1989 ◽  
Vol 70 (4) ◽  
pp. 545-550 ◽  
Author(s):  
Peter J. Benson ◽  
Joo Ho Sung
Keyword(s):  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Content Type ◽  
Histological Features ◽  
Autopsy Examination ◽  
Cerebellar Medulloblastoma ◽  
Radiation Induced ◽  
The Brain ◽  
Fine Print ◽  
Saccular Aneurysms

✓ Three patients, two males and one female aged 21, 14, and 31 years, respectively, developed cerebral saccular aneurysms several years after undergoing radiotherapy for cerebellar medulloblastoma at 2, 5, and 14 years of age, respectively. Following surgery, all three received combined cobalt-60 irradiation and intrathecal colloidal radioactive gold (198Au) therapy, and died from rupture of the aneurysm 19, 9, and 17 years after the radiotherapy, respectively. Autopsy examination revealed no recurrence of the medulloblastoma, but widespread radiation-induced vasculopathy was found at the base of the brain and in the spinal cord, and saccular aneurysms arose from the posterior cerebral arteries at the basal cistern or choroidal fissure. The aneurysms differed from the ordinary saccular aneurysms of congenital type in their location and histological features. Their locations corresponded to the areas where intrathecally administered colloidal 198Au is likely to pool, and they originated directly from a segment of the artery rather than from a branching site as in congenital saccular aneurysms. It is, therefore, concluded that the aneurysms in these three patients were most likely radiation-induced.

Intraoperative use of real-time ultrasonography in neurosurgery

1982 ◽  
Vol 57 (2) ◽  
pp. 157-163 ◽  
Author(s):  
William F. Chandler ◽  
James E. Knake ◽  
John E. McGillicuddy ◽  
Kevin O. Lillehei ◽  
Terry M. Silver
Keyword(s):  
Arteriovenous Malformation ◽  
Real Time ◽  
Operating Room ◽  
Ventricular Catheter ◽  
Neurosurgical Procedures ◽  
Content Type ◽  
Brain Surface ◽  
The Brain ◽  
Real Time Ultrasonography ◽  
Fine Print

✓ The authors' experience with the intraoperative use of real-time ultrasonography during 21 neurosurgical procedures is reported. These procedures include neoplasm surgery in 18 cases, treatment of an arteriovenous malformation in one case, and ventricular catheter placement for hydrocephalus in two cases. In each of the neoplasm cases, the tumors were imaged just as well through the intact dura as on the brain surface itself. There were no cases in which the pathology could not easily be identified. The use of portable intraoperative ultrasonography in sterile coverings has proven to be extremely useful in localizing small subcortical neoplasms, as well as locating the solid and cystic portions of deep lesions. It has assisted in guiding needles for both biopsy and aspiration. It has also accurately identified and guided Silastic catheters during their placement in the ventricular system in cases of hydrocephalus. The authors have found real-time ultrasonography to be an important new tool in the operating room and will continue to rely on its imaging ability during selected procedures in the future.

Arteriovenous anomaly of the brain associated with cerebral aneurysm

1971 ◽  
Vol 34 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Henry A. Shenkin ◽  
Felix Jenkins ◽  
Kwang Kim
Keyword(s):  
Blood Flow ◽  
Cerebral Aneurysm ◽  
Parent Vessel ◽  
Content Type ◽  
Large Aneurysm ◽  
The Brain ◽  
Fine Print ◽  
Feeding Vessel

✓ The removal of an arteriovenous anomaly of the brain resulted in a distinct reduction in the size of a large aneurysm located upon its principal feeding vessel. This confirms previous inferences that the development of aneurysms is related to the amount of blood flow in the parent vessel.

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