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Firlik AD, Kaufmann AM, Jungreis CA, Yonas H. Effect of transluminal angioplasty on cerebral blood flow in the management of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. J Neurosurg 1997; 86:830-9. [PMID: 9126899 DOI: 10.3171/jns.1997.86.5.0830] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this study the authors have examined the effects of transluminal angioplasty on cerebral blood flow (CBF) in the management of intractable vasospasm following aneurysmal subarachnoid hemorrhage (SAH). Fourteen consecutively enrolled patients underwent attempted angioplasty with or without intraarterial infusion of papaverine. Twelve patients underwent pre- and postangioplasty xenon-enhanced computerized tomography (Xe-CT) scanning to measure regional CBF in 55 to 65 regions of interest (ROIs) per patient. Angioplasty was possible in 13 (93%) of 14 patients, with angiographically demonstrated improvement in all 13. Twelve (92%) of the 13 patients were neurologically improved following angioplasty; seven (58%) of the 12 patients who improved had a complete reversal of all delayed ischemic deficits. Angioplasty significantly decreased the mean number of ROIs at risk (11.4 ROIs pre- and 0.9 ROIs postangioplasty) (p < 0.00005, t-test). All patients had a reduction in the number of ROIs at risk after angioplasty; six (50%) of 12 no longer had any ROIs remaining at risk after angioplasty. Angioplasty significantly increased the mean CBF within at-risk ROIs (13 ml/100 g/minute pre- and 44 ml/100 g/minute postangioplasty) (p < 0.00005, t-test). All patients experienced an improvement in mean CBF in at-risk ROIs after angioplasty, with the mean CBF improving to above 20 ml/100 g/minute in all cases. No differences in the degree of improvement were found in patients who received intraarterial papaverine compared with those who did not. In the majority of patients with refractory vasospasm following SAH, angioplasty effectively dilated spastic arteries, reversed delayed neurological deficits, and significantly improved CBF in areas of brain at risk of infarction.
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152
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Adelson PD, Clyde B, Kochanek PM, Wisniewski SR, Marion DW, Yonas H. Cerebrovascular response in infants and young children following severe traumatic brain injury: a preliminary report. Pediatr Neurosurg 1997; 26:200-7. [PMID: 9436831 DOI: 10.1159/000121192] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To further describe the pathophysiologic processes that occur in infants and young children after severe traumatic brain injury (TBI), we retrospectively reviewed the cerebral blood flow (CBF) values and 6-month Glasgow Outcome Scores (GOS) in 30 children < or = 8 years old (25 were < or = 4 years old) with a Glasgow Coma Score (GCS) on admission of < or = 8. Twelve females and 18 males (mean age 2.1 years, range 1 month to 8 years) underwent 61 CBF studies using stable xenon computed tomography at variable times from admission to 9 days after TBI. In 12 patients, PaCO2 was manipulated an average of 8.4 torr (range 5-11 torr) and a second CBF study performed to determine CO2 vasoreactivity (CO2VR), defined as the percent change in CBF per torr change in PaCO2. CBF on admission (n = 13)was 25.1+/-7.7 ml/100 g/min (mean +/- SEM) and was < or = 20 ml/100 g/min in 10 of 13 patients (77%). By 24 h and for up to 6 days after TBI, the mean CBF increased to 55.3+/-3.4 ml/100 g/min (range 2-95) which differed significantly from the admission CBF value (p < 0.05); a CBF of >70 ml/100 g/min tended to be associated with a good outcome. Poor outcome (GOS < or = 3) was seen uniformly in children under the age of 1 year and in patients with a CBF of < or = 20 ml/100 g/min any time after TBI. Poor outcome was seen in 85% of children under the age of 24 months, but in only 41% of children > or = 24 months old. Mean CO2VR was 2.1+/-0.6%/torr PaCO2 and ranged from 0.02 to 5.98%. Mean CO2VR tended to differ between good and poor outcome children (3.2+/-0.9 and 1.17+/-0.2%, respectively) and a CO2VR of < or = 2% was significantly associated with a poor outcome. Younger age, low CBF in the early period after TBI, and a CO2VR of <2% was associated with a poor outcome in this subgroup of children. Young children (<24 months) may represent a particular high-risk group with early hypoperfusion after severe TBI. This finding may be a key factor in the pathophysiology and outcome in this age group, and may need to be addressed in our future therapeutic protocols.
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153
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Foutrakis GN, Yonas H, Sclabassi RJ. Finite element methods in the simulation and analysis of intracranial blood flow. Neurol Res 1997; 19:174-86. [PMID: 9175148 DOI: 10.1080/01616412.1997.11740793] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This paper presents an introduction to the use of finite element methods in the simulation and analysis of intracranial blood flow and lays the foundation for more detailed clinically oriented studies. An overview of finite element theory is provided and includes the formulation of both the continuous and discrete equations of viscous fluid flow. A discussion of appropriate assumptions and boundary conditions governing arterial blood flow is presented. Two-dimensional, rigid-walled models are developed for flow in a straight artery, a 90 degrees curved artery and a bifurcated artery. For each model, a description of the finite element mesh, numerical solution and computational results are presented. This paper is the first in a series which will detail computational analysis of the relationship between pressure, velocity development of intracranial aneurysms and therapeutic approaches to aneurysm management. The goals of this research are to investigate the fluid dynamics that arise as a result of pulsatile flow in the arteries of the circle of Willis, relate these hemodynamics to the formation of aneurysms, develop a computational understanding of the effects of various therapies on blood flow related to aneurysms, and to develop and utilize patient specific computer simulations for treatment planning.
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154
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Comey CH, Kondziolka D, Yonas H. Regional parenchymal enhancement with mixed cavernous/venous malformations of the brain. J Neurosurg 1997. [DOI: 10.3171/jns.1997.86.1.0154] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
✓ With improvements in imaging technology, the detection of both cavernous malformations and venous malformations has increased markedly in recent years. Although much has been learned about the association of cavernous and venous malformations, important questions regarding the true nature of such a relationship remain unanswered. It has been proposed that certain venous malformations produce local venous hypertension with resultant microhemorrhage, growth factor release, and creation of cavernous malformations. The authors report on two patients with cerebellopontine venous malformations associated with cavernous malformations. Both patients demonstrated persistent regional parenchymal enhancement associated with the vascular malformations. In addition, both patients had significant clinical symptoms referable to the region of affected brain. This previously undescribed finding may represent an imaging correlate to the complex interaction among venous malformations, venous hypertension, and cavernous malformations.
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155
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Nemoto EM, Kofke WA, Yonas H, Williams D, Rose M, Rao G, Simplaceanau E. Regional cerebral blood flow after subarachnoid hemorrhage (SAH) in the rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 411:313-8. [PMID: 9269442 DOI: 10.1007/978-1-4615-5865-1_38] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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156
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Comey CH, Kondziolka D, Yonas H. Regional parenchymal enhancement with mixed cavernous/venous malformations of the brain. Case report. J Neurosurg 1997; 86:155-8. [PMID: 8988095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
With improvements in imaging technology, the detection of both cavernous malformations and venous malformations has increased markedly in recent years. Although much has been learned about the association of cavernous and venous malformations, important questions regarding the true nature of such a relationship remain unanswered. It has been proposed that certain venous malformations produce local venous hypertension with resultant microhemorrhage, growth factor release, and creation of cavernous malformations. The authors report on two patients with cerebellopontine venous malformations associated with cavernous malformations. Both patients demonstrated persistent regional parenchymal enhancement associated with the vascular malformations. In addition, both patients had significant clinical symptoms referable to the region of affected brain. This previously undescribed finding may represent an imaging correlate to the complex interaction among venous malformations, venous hypertension, and cavernous malformations.
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157
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Nemoto EM, Klementavicius R, Melick JA, Yonas H. Norepinephrine Activation of Basal Cerebral Metabolic Rate for Oxygen (CMRO (2)) During Hypothermia in Rats. Anesth Analg 1996. [DOI: 10.1213/00000539-199612000-00023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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158
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Nemoto EM, Klementavicius R, Melick JA, Yonas H. Norepinephrine activation of basal cerebral metabolic rate for oxygen (CMRO2) during hypothermia in rats. Anesth Analg 1996; 83:1262-7. [PMID: 8942597 DOI: 10.1097/00000539-199612000-00023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In an earlier study on the effect of mild hypothermia (34 degrees C) on the cerebral metabolic rate for oxygen (CMRO2) in rats, we used norepinephrine (NE) to support arterial blood pressure while inducing isoelectricity on the electroencephalogram (EEG) with thiopental (TP). Even with administration of sufficient TP to reduce a fully active EEG to an isoelectric EEG, CMRO2 was often unchanged. Based on this observation, we hypothesized that NE had activated CMRO2 despite thiopental coma. Therefore, we studied the effect of NE compared with donor blood (DB) infusion to maintain arterial blood pressure during TP-induced isoelectric EEG on whole-brain CBF (H2 clearance) and CMRO2 during normothermia (38 degrees C) and mild hypothermia (34 degrees C) in rats during 70% N2O/30% O2 analgesia. Cerebral blood flow (CBF) and CMRO2 were measured in four groups of rats at 38 degrees C followed by measurements at either 38 degrees C (two groups) or 34 degrees C (two groups) and during TP-induced EEG isoelectricity. Within each of the two groups at 38 degrees C and 34 degrees C, arterial pressure was sustained by either DB (n = 10) or NE (n = 9) infusion. At 38 degrees C, CMRO2 in the DB and NE groups was 7.92 +/- 1.05 and 6.4 +/- 0.80 mL x 100 g-1.min-1 and decreased to 50% of normal (3.95 +/- 0.70 and 3.32 +/- 0.40 mL x 100 g-1.min-1, respectively) during TP isoelectricity for a functional:basal CMRO2 distribution of 50% +/- 4% and 50% +/- 4%. At 34 degrees C, CMRO2 values in the DB and NE groups were 6.31 +/- 1.41 and 5.41 +/- 2.02 mL x 100 g-1.min-1, respectively. During TP-induced isoelectricity, CMRO2 values in both groups were reduced to 2.37 +/- 0.43 and 3.55 +/- 1.27 mL x 100g-1.min-1, respectively, resulting in a functional:basal CMRO2 distribution of 61%:38% in the DB group and the reverse, or 27%:73%, in the Ne group. Basal CMRO2 was significantly (P < 0.05) larger in the NE-infused rats. These results suggest that NE infusion, by increasing CMRO2 during mild hypothermia, could nullify its protective effects in the ischemic brain.
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159
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Caplan LR, Piepgras DG, Quest DO, Toole JF, Samson D, Futrell N, Millikan C, Flamm ES, Heros RC, Yonekawa Y, Eguchi T, Yonas H, Rothbart D, Spetzler RF. EC-IC bypass 10 years later: is it valuable? SURGICAL NEUROLOGY 1996; 46:416-23. [PMID: 8874538 DOI: 10.1016/s0090-3019(96)90802-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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160
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Yonas H, Pindzola RP, Johnson DW. Xenon/computed tomography cerebral blood flow and its use in clinical management. Neurosurg Clin N Am 1996; 7:605-16. [PMID: 8905775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The main advantages of stable Xe/CT is that it noninvasively provides rapid access to high-resolution, quantitative, local CBF information coupled to CT anatomy. The information obtained is valid even in disease states because a partition coefficient is directly calculated for each voxel as small as 1 x 1 x 5 mm3. CBF studies can be repeated within 20 minutes, allowing the assessment of hemodynamic states. The technology can be incorporated into all existing CT technology at relatively little expense. The disadvantages are the radiation dose from the CT scanner, the pharmacologic effects of xenon gas, and the limitations of survey. The radiation dose is significant but it is focused to the least radiation-sensitive region of the body (scalp, skull, and brain) so that the effective cancer causation risk is lower than any other CBF study that delivers isotope indescriminatly to the body. The pharmacologic properties of xenon are associated with several potential problems. Xenon alters the sensorium of many individuals and may cause patient motion. This can be minimized with careful prestudy positioning and reassurance of the patient during the study. Most patients find the sensation enjoyable; however, occasionally, a patient cannot tolerate the perception of "losing control" and the study has to be stopped. One of the concerns regarding Xe/CT is that at the 80% level, xenon has anesthetic properties. At less than 33% xenon (with the difference being oxygen), the side effects have, in fact, been few and transient, with a mild hyperesthetic and disassociated feeling being the rule. Although xenon-induced apnea was reported as a consequence of xenon inhalation, the report involved the inhalation of 100% xenon, and at the levels recommended for imaging, holding one's breath for more than 20 seconds is rare. The other concern is the degree of flow activation that occurs with xenon inhalation and its effect on the accuracy of the measurements. In part, because of the "robust" nature of the Kety-Schmidt equations and because a significant xenon-induced flow activation is delayed for about 2 minutes, the effect of the flow activation is, in fact, minimal (less than 5% elevation of calculated flow values from true values). Although an earlier study by Obrist36 suggested that the error induced by flow activation was significant, a recent computer simulation study by the same author identified a maximal theoretical error of less than 5%. Previously, Xe/CT studies were limited to three brain levels, but with the new helical CT scanners, nine levels can now be studied. Most of the concerns over the technology have been resolved (Table 1). As a result, more clinicians around the world are beginning to use this technology when they need rapid access to quantitative CBF information about their patients.
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161
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Yonas H, Pindzola RR, Johnson DW. Xenon/Computed Tomography Cerebral Blood Flow and its use in Clinical Management. Neurosurg Clin N Am 1996. [DOI: 10.1016/s1042-3680(18)30349-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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162
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Klementavicius R, Nemoto EM, Yonas H. The Q10 ratio for basal cerebral metabolic rate for oxygen in rats. J Neurosurg 1996; 85:482-7. [PMID: 8751636 DOI: 10.3171/jns.1996.85.3.0482] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Previously the authors showed that hypothermia exerts a greater effect on the cerebral metabolic rate for oxygen (CMRO2) that is associated with the maintenance of cellular viability, or "basal" CMRO2, than on electroencephalogram (EEG)-associated CMRO2 or "functional" CMRO2. On the basis of their findings, the authors hypothesized that the ratio of CMRO2 over a 10 degrees C temperature range (Q10) for basal CMRO2 was greater than that for functional and total CMRO2. They tested their hypothesis by determining the Q10 for basal CMRO2 from 38 degrees C to 28 degrees C. They measured whole-brain cerebral blood flow (CBF) and CMRO2 in six rats during progressive hypothermia at a brain temperature of 38 degrees C and, after induction of an isoelectric EEG signal (50 microV/cm) with thiopental sodium, they repeated the measurements at 38 degrees C, 34 degrees C, 30 degrees C, and 28 degrees C. In a control group (five rats), six sequential measurements of CBF and CMRO2 were made while the animals were anesthetized by 0.5% isoflurane/70% N2O/30% O2 at a brain temperature of 38 degrees C over a time span equivalent to the hypothermic group, that is, approximately 3 hours. The Q10 for basal CMRO2 calculated over 38 degrees C to 28 degrees C was 5.2 +/- 0.92. However, the decrease in basal CMRO2 between 38 degrees C and 28 degrees C was nonlinear on a log plot, revealing a two-component response: a high temperature sensitivity component between 38 degrees C and 30 degrees C with a Q10 of 12.1, and a lower temperature sensitivity component between 30 degrees C and 28 degrees C with a Q10 of 2.8. The combined overall Q10 for basal CMRO2 between 38 degrees and 28 degrees C was 5.2. The energy-requiring processes associated with these high and low temperature sensitivity components of basal CMRO2 have yet to be identified.
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163
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Firlik AD, Firlik KS, Yonas H. Physiological diagnosis and surgical treatment of recurrent limb shaking: case report. Neurosurgery 1996; 39:607-11. [PMID: 8875496 DOI: 10.1097/00006123-199609000-00037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE AND IMPORTANCE Although recurrent limb shaking has been observed in patients with carotid occlusion, its cause, method of diagnosis, and definitive treatment have yet to be fully elucidated. This report examines the cerebrovascular physiology of a patient with recurrent limb shaking by means of xenon-enhanced computed tomographic (XeCT) scanning. By measuring cerebral blood flow (CBF) and cerebrovascular reserve capacity, we were able to confirm both the clinical diagnosis and the response to treatment on physiological grounds. CLINICAL PRESENTATION The patient is a 49-year-old man who presented with frequent brief attacks of left arm and leg shaking that occurred at standing or coughing. After cervical radiation therapy for a laryngeal carcinoma, he was found to have bilateral carotid occlusion with minimal collateral development. XeCT scans revealed borderline ischemic perfusion and lack of cerebrovascular reserve in response to an acetazolamide vasodilatory challenge. INTERVENTION The patient underwent a right superficial temporal artery to middle cerebral artery bypass to augment cerebral perfusion. CONCLUSION After the procedure, the patient's limb shaking attacks ceased. The postoperative XeCT scan showed improved CBF and a return of cerebrovascular reserve capacity. Recurrent limb shaking is a manifestation of decreased CBF. Quantitative XeCT CBF studies coupled with vasodilatory challenge is an important way to assess patients with cerebrovascular disorders and thus identify individuals who will benefit from cerebral revascularization.
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164
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Firlik AD, Firlik KS, Yonas H. Physiological Diagnosis and Surgical Treatment of Recurrent Limb Shaking: Case Report. Neurosurgery 1996. [DOI: 10.1227/00006123-199609000-00037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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165
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Foutrakis GN, Burgreen G, Yonas H, Sclabassi RJ. Construction of 3-D arterial volume meshes from magnetic resonance angiography. Neurol Res 1996; 18:354-60. [PMID: 8875456 DOI: 10.1080/01616412.1996.11740436] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Finite element methods are well-suited for solving problems in arterial fluid dynamics, primarily due to their ability to handle flows in complex geometries. However, in order to use these computational methods to develop realistic models of pulsatile flow in intracranial arteries and associated aneurysms, it is necessary to construct a 3-D mesh, or grid, that accurately duplicates the arterial geometry of interest. In this paper, we present an efficient method to accurately develop realistic 3-D computational meshes of human intracranial arteries and aneurysms from serial magnetic resonance angiography images. However, these techniques may be applied to any other form of imaging data including computed tomographic angiography. First, raw grayscale images are segmented, converted to their binary form and arterial contours are extracted at each image slice. Next, the arterial contours are stacked and cubic splines are computed along the axial direction. This creates an affect similar to smooth integration in the axial direction and provides a set of points that define the 3-D arterial surface geometry. Then, surface patches are constructed and merged. A surface mesh is then computed with the ability to locally vary the mesh density as desired. Finally, nodal points on the surface mesh are used to compute the finite element volume mesh. The 3-D volume mesh accurately describes the arterial geometry and is used to develop patient-specific computational fluid dynamic models of flow phenomena in intracranial arteries and aneurysms. These flow models are then suitable for investigating the hemodynamics of intracranial aneurysm formation and test the end-effects of various medical and surgical treatments.
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166
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Nemoto EM, Yonas H, Kaufmann A, Jungreis C, Klementavicius R. Cerebrovascular responses to vasopressors before and after subarachnoid hemorrhage (SAH) in monkeys assessed by Xe/CT. Acta Neurol Scand 1996. [DOI: 10.1111/j.1600-0404.1996.tb00575.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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167
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Yonas H, Przybyiski GJ, Webster MW, Smith HA, Johnson DW. Diagnosis and treatment of high-risk patients from symptomatic carotid occlusive disease with STA-MCA bypass. Acta Neurol Scand 1996. [DOI: 10.1111/j.1600-0404.1996.tb00567.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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168
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Clyde BL, Pryzbylski GJ, Bonaroti EA, Yonas H. Use of Xenon/CT CBF in the management of acute carotid injuries. Acta Neurol Scand 1996. [DOI: 10.1111/j.1600-0404.1996.tb00571.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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169
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Clyde BL, Yonas H, Smith HA, Resnick DK, Kaufmann AM. The relationshp of transcranial Doppler velocity to stable Xenon/CT cerebral blood flow following aneurysmal subarachnoid hemorrhage. Acta Neurol Scand 1996. [DOI: 10.1111/j.1600-0404.1996.tb00577.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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170
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Clyde BL, Resnick DK, Yonas H, Smith HA, Kaufmann AM. The relationship of blood velocity as measured by transcranial doppler ultrasonography to cerebral blood flow as determined by stable xenon computed tomographic studies after aneurysmal subarachnoid hemorrhage. Neurosurgery 1996; 38:896-904; discussion 904-5. [PMID: 8727814 DOI: 10.1097/00006123-199605000-00008] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Transcranial doppler (TCD) ultrasonography is often used to guide the management of patients with subarachnoid hemorrhage (SAH). However, the correlation between increased blood velocity as measured by TCD ultrasonography and angiographic vasospasm was established before the routine use of hypervolemia/hemodilution and administration of nimodipine and did not address blood flow. The relationship of blood velocity as measured by TCD ultrasonography and local cerebral blood flow (LCBF) in SAH managed with these modalities is unknown. Patients presenting with aneurysmal SAH between January 1992 and September 1993 who underwent TCD ultrasonography and xenon computed tomographic (Xe/CT) LCBF studies within 12 hours were retrospectively studied. Fifty patients underwent a total of 94 paired studies, encompassing 709 vascular territories. All were treated with nimodipine and hypervolemia/hemodilution. Hematocrit, blood pressure, and partial carbon dioxide pressure were similar at the time of TCD ultrasonography and Xe/CT measurement of LCBF. When LCBF in the middle cerebral artery (MCA) was < or = 31 ml/100 g/min, the corresponding peak systolic velocity measured by TCD ultrasonography was 119 cm/s, whereas those > 31 ml/100 g/min had a velocity of 169 cm/s (P = 0.006). High LCBF was associated with high velocity in all vascular territories, reaching significance in all but the internal carotid artery. At the time of each study, 41 neurological examinations were focal and 53 were nonfocal. The Xe/CT measurement of LCBF in the MCA contralateral to a deficit was significantly less than in territories without corresponding clinical deficits (P = 0.01), whereas peak systolic velocities in the MCA were not significantly different (P = 0.71). Territories with increases in blood velocity in the MCA of > 50 cm/s/24 h did not have statistically different LCBF (P = 0.183). Our results suggest that increased blood velocity revealed by TCD ultrasonography correlates with increased LCBF and not with ischemia. No difference in LCBF was found in territories with and without rapid increases in blood velocity in the MCA. Furthermore, although focal neurological deficits corresponded with decreased contralateral LCBF in the MCA, increased velocity did not correlate with neurological findings. Therapeutic decisions based solely on blood velocity revealed by TCD ultrasonography might be inappropriate and potentially harmful. Xe/CT studies of LCBF are useful in guiding the management of SAH.
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MESH Headings
- Aneurysm, Ruptured/diagnosis
- Aneurysm, Ruptured/physiopathology
- Aneurysm, Ruptured/surgery
- Blood Flow Velocity/physiology
- Brain/blood supply
- Dominance, Cerebral/physiology
- Female
- Humans
- Image Processing, Computer-Assisted
- Intracranial Aneurysm/diagnosis
- Intracranial Aneurysm/physiopathology
- Intracranial Aneurysm/surgery
- Ischemic Attack, Transient/diagnosis
- Ischemic Attack, Transient/physiopathology
- Ischemic Attack, Transient/surgery
- Male
- Middle Aged
- Postoperative Complications/diagnosis
- Postoperative Complications/physiopathology
- Regional Blood Flow/physiology
- Retrospective Studies
- Sensitivity and Specificity
- Subarachnoid Hemorrhage/diagnosis
- Subarachnoid Hemorrhage/physiopathology
- Subarachnoid Hemorrhage/surgery
- Systole/physiology
- Tomography, X-Ray Computed
- Treatment Outcome
- Ultrasonography, Doppler, Transcranial
- Xenon
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171
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Clyde BL, Firlik AD, Kaufmann AM, Spearman MP, Yonas H. Paradoxical aggravation of vasospasm with papaverine infusion following aneurysmal subarachnoid hemorrhage. Case report. J Neurosurg 1996; 84:690-5. [PMID: 8613866 DOI: 10.3171/jns.1996.84.4.0690] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Reports of intraarterial papaverine infusion as treatment for cerebral vasospasm are few and documented complications are uncommon. The authors report the case of a patient with paradoxical aggravation of cerebral arterial narrowing during selective intraarterial papaverine infusion intended to treat vasospasm following aneurysmal subarachnoid hemorrhage (SAH). A 48-year-old man presented to the authors' service with symptomatic vasospasm 10 days after experiencing an SAH. The ruptured anterior communicating artery aneurysm was surgically obliterated the following day, and thereafter maximum hypervolemic and hypertensive therapies were used. However, the patient remained lethargic, and a stable xenon-computerized tomography (CT) cerebral blood flow (CBF) study revealed CBF to be 15 cc/100 g/minute in the left anterior cerebral artery (ACA) and 25 cc/100 g/minute in the right ACA territories. Cerebral arteriography demonstrated diffuse severe left ACA and mild left middle cerebral artery (MCA) vasospasm. In response intraarterial papaverine was infused into the internal carotid artery just proximal to the ophthalmic artery. During the infusion the patient became aphasic and exhibited right hemiplegia. Arteriography performed immediately after the intraarterial papaverine infusion revealed diffuse exacerbation of vasospasm in the distal ACA and MCA territories. A repeat xenon-CT CBF study showed that CBF in the left ACA and the MCA had drastically decreased (2 cc/100 g/minute and 10 cc/100 g/minute, respectively). Despite aggressive management, infarction ultimately developed. This is the first clinical case to illustrate a paradoxical effect of intraarterial papaverine treatment for vasospasm following aneurysmal SAH. The possible mechanisms of this paradoxical response and potential therapeutic reactions are reviewed.
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Klementavicius R, Nemoto EM, Yonas H. Basal Q10 for cerebral metabolic rate for oxygen (CMRO2) in rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 388:191-5. [PMID: 8798811 DOI: 10.1007/978-1-4613-0333-6_23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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173
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Nemoto EM, Klementavicius R, Melick JA, Yonas H. Suppression of cerebral metabolic rate for oxygen (CMRO2) by mild hypothermia compared with thiopental. J Neurosurg Anesthesiol 1996; 8:52-9. [PMID: 8719194 DOI: 10.1097/00008506-199601000-00012] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
If the efficacy of hypothermia and barbiturates in ameliorating ischemic brain injury lies in reducing the cerebral metabolic rate of oxygen (CMRO2), the greater efficacy of mild hypothermia (34 degrees C) compared with barbiturates is inconsistent with the 15-20% reduction of CMRO2 caused by mild hypothermia compared with 50% caused by barbiturates. This paradox, we hypothesized, derives from the fact that whereas barbiturates lower CMRO2 associated with EEG activity or thiopental (TP)-suppressible CMRO2, not essential for cellular viability, hypothermia lowers CMRO2 associated with providing energy, i.e., adenosine triphosphate, to maintain transmembrane ion gradients or TP-nonsuppressible CMRO2, essential for neuronal viability. To test this hypothesis, we measured whole brain cerebral blood flow (CBF) and CMRO2 in two groups of rats mechanically ventilated with 70% N2O/30% O2 before and after TP-induced isoelectric EEG. In the normothermic group (n = 7), measurements were made at a brain temperature (Tb) of 38 degrees C, while in the hypothermic group (n = 7), they were made at 34 degrees C. In the normothermic group, TP-induced isoelectric EEG reduced CMRO2 by 50%, from 7.92 +/- 1.05 to 3.95 +/- 0.70 ml 100 g-1 min-1 (mean +/- = SD). Thus, at 38 degrees C, TP-suppressible and TP-nonsuppressible CMRO2 were both 50 +/- 4% of total CMRO2. In the hypothermic group, decreasing Tb from 38 to 34 degrees C caused a 17% decline in CMRO2, from 7.62 +/- 1.92 to 6.28 +/- 1.22 ml 100 g-1 min-1 (p > 0.05). AT 34 degrees C, TP infusion lowered CMRO2 to 2.15 = 0.46 ml 100 g-1 min-1. At 34 degrees C, TP-suppressible and TP-nonsuppressible CMRO2 values were 64 +/- 7% and 36 +/- 8% of total CMRO2, respectively. TP lowered CBF by 50% at both 38 and 34 degrees C. In conclusion, mild hypothermia selectively lowers TP-nonsuppressible CMRO2 associated with the maintenance of viability rather than EEG-associated or TP-suppressible CMRO2.
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Horowitz M, Yonas H, Albright AL. Evaluation of cerebral blood flow and hemodynamic reserve in symptomatic moyamoya disease using stable Xenon-CT blood flow. SURGICAL NEUROLOGY 1995; 44:251-61; discussion 262. [PMID: 8545777 DOI: 10.1016/0090-3019(95)00188-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Moyamoya disease is a vascular abnormality seen in children and adults characterized by progressive narrowing of the internal carotid, middle, anterior, and posterior cerebral arteries and the development of leptomeningeal and proximal internal carotid artery collaterals, which appear diaphanous on angiogram. Although adults tend to present with subarachnoid hemorrhage and children with ischemic events, the clinical sequelae in these two populations overlap. Expanding upon work done at this institution using stable xenon computer tomographic blood flow determinations with acetazolamide and carbon dioxide challenge to predict which population of patients with severe carotid disease and hemodynamic compromise would benefit from surgical intervention, we used similar rationale to determine which patients with moyamoya disease would likely benefit from revascularization. Data and outcome concerning four such patients make up the body of this report.
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Findlay JM, Kassell NF, Weir BK, Haley EC, Kongable G, Germanson T, Truskowski L, Alves WM, Holness RO, Knuckey NW, Yonas H, Steinberg GK, West M, Winn HR, Ferguson G. A Randomized Trial of Intraoperative, Intracisternal Tissue Plasminogen Activator for the Prevention of Vasospasm. Neurosurgery 1995. [DOI: 10.1227/00006123-199507000-00041] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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176
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Yonas H, Kaufmann A. Combined extracranial-intracranial bypass and intraoperative balloon occlusion for the treatment of intracavernous and proximal carotid artery aneurysms. Neurosurgery 1995; 36:1234. [PMID: 7644011 DOI: 10.1097/00006123-199506000-00036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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177
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Yonas H, Kaufmann A. Combined Extracranial-Intracranial Bypass and Intraoperative Balloon Occlusion for the Treatment of Intracavernous and Proximal Carotid Artery Aneurysms. Neurosurgery 1995. [DOI: 10.1227/00006123-199506000-00036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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178
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Clyde B, Yonas H, Kaufmann AM, Jungreis CA. Vascular Considerations and Complications in Cranial Base Surgery. Neurosurgery 1995. [DOI: 10.1227/00006123-199505000-00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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179
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Clyde B, Yonas H, Kaufmann AM, Jungreis CA. Vascular considerations and complications in cranial base surgery. Neurosurgery 1995; 36:1058-60. [PMID: 7791977 DOI: 10.1227/00006123-199505000-00034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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180
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Mathis JM, Barr JD, Jungreis CA, Yonas H, Sekhar LN, Vincent D, Pentheny SL, Horton JA. Temporary balloon test occlusion of the internal carotid artery: experience in 500 cases. AJNR Am J Neuroradiol 1995; 16:749-54. [PMID: 7611033 PMCID: PMC8332245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE To describe experience with 500 temporary balloon occlusions of the internal carotid artery, with particular emphasis on the techniques and complications. METHODS Temporary occlusion of the internal carotid artery was accomplished endovascularly using various balloon-catheter combinations. These temporary balloon occlusions were combined, when possible, with cerebral blood flow analysis with stable xenon-enhanced CT. RESULTS Complications related to this procedure occurred in 16 (3.2%) patients. Eight (1.6%) patients had asymptomatic complications. There were 8 who experienced neurologic changes. Six (1.2%) of these were transient; two (0.4%) were permanent. There were no deaths. CONCLUSIONS Temporary balloon occlusion of the internal carotid artery, believed helpful in identifying patients at risk of stroke during abrupt carotid artery sacrifice, can be performed with an acceptably low complication rate.
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181
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Barr JD, Horowitz MB, Mathis JM, Sclabassi RJ, Yonas H. Intraoperative urokinase infusion for embolic stroke during carotid endarterectomy. Neurosurgery 1995; 36:606-11. [PMID: 7753364 DOI: 10.1227/00006123-199503000-00024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Embolic stroke is an infrequent complication of carotid endarterectomy. Somatosensory evoked potential monitoring detected delayed acute neurological deterioration during endarterectomy performed on a 71-year-old woman. Intraoperative arteriography performed via an indwelling shunt revealed thrombus within the middle cerebral artery and distal branches. A microcatheter was placed into the internal carotid artery via the arteriotomy and advanced into the middle cerebral artery. Urokinase was infused into and around the thrombus until almost complete thrombolysis had been achieved. The patient recovered quickly and was discharged without neurological deficit.
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182
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Barr JD, Horowitz MB, Mathis JM, Sclabassi RJ, Yonas H. Intraoperative Urokinase Infusion for Embolic Stroke during Carotid Endarterectomy. Neurosurgery 1995. [DOI: 10.1097/00006123-199503000-00024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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183
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Durham S, Yonas H, Aggarwal S, Darby J, Kramer D. Regional cerebral blood flow and CO2 reactivity in fulminant hepatic failure. J Cereb Blood Flow Metab 1995; 15:329-35. [PMID: 7860666 DOI: 10.1038/jcbfm.1995.38] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Alterations in cerebral hemodynamics are postulated to contribute to brain herniation, a major cause of death in patients with severe hepatic encephalopathy due to fulminant hepatic failure (FHF). In an effort to identify these changes in cerebral hemodynamics, regional and global cerebral blood flow (CBF) and CO2 reactivity were measured using stable xenon-enhanced computed tomography (Xe/CT) in 24 patients within 72 h of onset of severe hepatic encephalopathy. Regional variations in CBF, most notably, a relative decrease in CBF in the anterior circulation and an increase in CBF in the posterior circulation were found. CBF was significantly lower in FHF patients compared with controls, however, these values are well out of the established ischemic range. FHF patients also showed significant impairment in CBF response to hypoventilation, while the CBF response to hyperventilation remained intact. This study suggests that FHF patients demonstrate early changes in both CBF patterns and CO2 reactivity. The relatively "normal" CBF values obtained in FHF patients in severe hepatic encephalopathy coupled with the lack of vasodilatation to hypoventilation suggest a state of uncoupled CBF and metabolism or "luxury perfusion" that could theoretically contribute to vasogenic edema, brain swelling, and cerebral herniation.
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184
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Webster MW, Makaroun MS, Steed DL, Smith HA, Johnson DW, Yonas H. Compromised cerebral blood flow reactivity is a predictor of stroke in patients with symptomatic carotid artery occlusive disease. J Vasc Surg 1995; 21:338-44; discussion 344-5. [PMID: 7853605 DOI: 10.1016/s0741-5214(95)70274-1] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE The purpose of this study was to determine whether the hemodynamic consequences of extracranial carotid disease correlate with the risk of subsequent cerebral infarction. METHODS In 95 patients with symptoms who had greater than or equal to 70% stenosis (31 patients) or who had occlusion (64 patients) of the ipsilateral carotid artery, cerebral blood flow was measured by the stable xenon/computed tomography technique both at baseline and after vasodilatory challenge with intravenous acetazolamide. Patients were stratified into group 1, 43 patients with no more than a 5% decrease in flow in any vascular territory, and group 2, 52 patients with greater than a 5% decrease in one or more vascular territories after an acetazolamide challenge. RESULTS In group 2, 15 (28.9%) of 52 patients had a new stroke, but only one (2.3%) of 43 patients in group 1 did (p = 0.0005). Of patients with total carotid occlusion 10 (26%) of 38 in group 2 and none (0%) of 26 in group 1 had a new stroke (p = 0.003). Of patients with greater than or equal to 70% stenosis, five (36%) of 14 in group 2 and only one (6%) of 17 in group 1 had a stroke (p = 0.067). CONCLUSION The loss of cerebral reactivity in patients with symptoms who had greater than or equal to 70% carotid stenosis or occlusion is an important predictor of impending cerebral infarction.
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185
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Baumann SB, Noll DC, Kondziolka DS, Schneider W, Nichols TE, Mintun MA, Lewine JD, Yonas H, Orrison WW, Sclabassi RJ. Comparison of Functional Magnetic Resonance Imaging with Positron Emission Tomography and Magnetoencephalography to Identify the Motor Cortex in a Patient with an Arteriovenous Malformation. ACTA ACUST UNITED AC 1995. [DOI: 10.3109/10929089509106324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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186
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Yonas H, Jungreis C. Xenon CT cerebral blood flow: past, present, and future. AJNR Am J Neuroradiol 1995; 16:219-20. [PMID: 7900599 PMCID: PMC8337694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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187
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Abstract
Local cerebral blood flow (LCBF) maps produced by 33% xenon-enhanced computed tomographic scanning (Xe/CT LCBF) are useful in the clinical diagnosis and management of patients with cerebrovascular disorders. However, observations in humans that 25-35% xenon (Xe) inhalation increases cerebral blood flow (CBF) have raised concerns that Xe/CT LCBF measurements may be inaccurate and that Xe inhalation may be hazardous in patients with decreased intracranial compliance. In contrast, 33% Xe does not increase CBF in rhesus monkeys. To determine whether this interspecies difference in the effect of Xe on CBF correlates with an interspecies difference in the anesthetic potency of Xe, we measured the minimum alveolar concentration (MAC) of Xe preventing movement to a tail-clamp stimulus in rhesus monkeys. Using a standard protocol for the determination of MAC in animals, we first measured the MAC of halothane (n = 5), and then used a combination of halothane and Xe to measure the MAC of Xe (n = 7). The halothane MAC was 0.99 +/- 0.12% (M +/- SD), and the Xe MAC was 98 +/- 15%. These results suggest that the MAC of Xe in rhesus monkeys is higher than the reported human Xe MAC value of 71%. Thus the absence of an effect of 33% Xe on CBF in the rhesus monkey may be related to its lower anesthetic potency.
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Smith HA, Thompson-Dobkin J, Yonas H, Flint E. Correlation of xenon-enhanced computed tomography-defined cerebral blood flow reactivity and collateral flow patterns. Stroke 1994; 25:1784-7. [PMID: 8073458 DOI: 10.1161/01.str.25.9.1784] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE A chronic compromise of cerebral hemodynamics has been shown to identify a group of patients at an increased risk for stroke. Because a "steal phenomenon" induced by a vasodilatory challenge has characterized the group at greatest risk, it was hypothesized that these individuals would also have a severe compromise of primary collaterals and an increased dependence on leptomeningeal collaterals. METHODS Twenty-three patients with symptomatic cerebrovascular disease underwent angiography and xenon-enhanced computed tomographic cerebral blood flow studies before and after 1 g IV acetazolamide within 6 months of each other. Cerebral blood flow vasoreactivity was classified by whether cerebral blood flow increased (> 5%) or was unchanged (+/- 5%) (group 1) or fell by > 5% (group 2) in any vascular territory. Angiographic collateralization was classified into four types: normal (type 1), willisian (type 2), ophthalmic (type 3), and leptomeningeal (type 4). RESULTS Twenty percent (2/10) of group 1 patients and 69% (9/13) of group 2 patients (P = .0009) had leptomeningeal collaterals. CONCLUSIONS A negative flow reactivity is significantly associated with a dependence on leptomeningeal collaterals and implies a state of maximal hemodynamic compromise.
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189
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Sekhar LN, Kalia KK, Yonas H, Wright DC, Ching H. Cranial base approaches to intracranial aneurysms in the subarachnoid space. Neurosurgery 1994; 35:472-81; discussion 481-3. [PMID: 7800139 DOI: 10.1227/00006123-199409000-00016] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The use of cranial base approaches to aneurysm surgery is illustrated by means of patient examples. Over a 9-year period, cranial base approaches were used to expose and treat 38 aneurysms involving the anterior communicating artery complex, proximal internal carotid artery, basilar artery, or vertebral artery. The approaches included orbital osteotomy, orbitozygomatic osteotomy, petrous apicectomy, presigmoid petrosectomy, and extreme lateral transcondylar methods. Complications related to the approaches included one partial ptosis and two cerebrospinal fluid leaks, which resolved with treatment. The technique of three-dimensional computed tomographic angiography was useful in delineating the vascular anatomy and its relation to the cranial base structures. This helped the surgeon plan the appropriate approach to the aneurysm. Cranial base approaches, used selectively, can provide improved exposure of deep-seated aneurysms and large or giant aneurysms, while minimizing brain retraction.
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190
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Webster MW, Downs L, Yonas H, Makaroun MS, Steed DL. The effect of arm exercise on regional cerebral blood flow in the subclavian steal syndrome. Am J Surg 1994; 168:91-3. [PMID: 8053533 DOI: 10.1016/s0002-9610(94)80042-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Reversed vertebral blood flow distal to a subclavian obstruction is not uncommon and rarely leads to stroke. A small subgroup of these patients have obstruction in other portions of the extracranial or intracranial circulation, however, and cerebrovascular symptoms are induced by arm exercise, which may decrease regional cerebral blood flow--at times to critical levels--indicating a true "steal" syndrome. We evaluated six patients with symptomatic subclavian steal syndrome using stable xenon with computed tomography cerebral blood flow mapping. A decrease in flow from 13% to 90% in one or more regional vascular territories was found after arm exercise. Patients with a true "steal" syndrome may be at higher risk for stroke. Measuring regional cerebral blood flow may be a means of detecting patients who have a critical loss of flow reserves and who will be symptomatically improved by cerebral revascularization.
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Nemoto EM, Yao L, Yonas H, Darby JM. Compartmentation of whole brain blood flow and oxygen and glucose metabolism in monkeys. J Neurosurg Anesthesiol 1994; 6:170-4. [PMID: 8081097 DOI: 10.1097/00008506-199407000-00004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The cerebral metabolic rate of oxygen (CMRO2) has been functionally compartmentalized using the barbiturate thiopental into active CMRO2, associated with electroencephalographic (EEG) activity, and the balance, basal CMRO2, associated with the maintenance of neuronal viability. Previous measurements of these CMRO2 compartments were made in anesthetized animals. Our aim was to determine whether the same proportions for these compartments applied in unanesthetized monkeys. The active: basal distribution of the cerebral metabolic rate of glucose (CMRG) and cerebral flood flow (CBF) were also determined. Three measurements of whole-brain CBF (H2 clearance), CMRO2, and CMRG were made in six unanesthetized rhesus monkeys (Macaca mulatta). Thereafter, thiopental anesthesia was induced and maintained until an isoelectric EEG was obtained. Three additional measurements of CBF, CMRO2, and CMRG were made. Arterial blood pressure, end-tidal CO2, and arterial blood gas were measured with each set of measurements. Thiopental-induced isoelectric EEG resulted in a 47% reduction in CMRO2 from 5.95 +/- 0.54 to 3.10 +/- 0.51 ml/100 g/min (mean +/- SD); a 36% reduction in CBF from 76 +/- 21 to 48 +/- 14 ml/100 g/min; and a 61% reduction in CMRG from 8.09 +/- 2.78 to 3.13 +/- 0.77 mg/100 g/min. The oxygen-glucose index was 0.99 +/- 0.10 for the whole brain, 0.87 +/- 0.15 for the active, and 1.27 +/- 0.25 for the basal compartments. These results indicated an active:basal distribution of approximately 50:50 for CMRO2, 40:60 for CBF, and 60:40 for CMRG. The active:basal CMRO2 distribution corroborates earlier data and shows that relative to CMRO2, the active compartment is underperfused with a lower oxygen-glucose index compared with the basal compartment.
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192
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Nemoto EM, Klementavicius R, Yonas H. Effects of hypothermia on cerebral metabolic rate for oxygen. J Neurosurg Anesthesiol 1994; 6:220-3. [PMID: 8081102 DOI: 10.1097/00008506-199407000-00024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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193
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Darby JM, Yonas H, Marks EC, Durham S, Snyder RW, Nemoto EM. Acute cerebral blood flow response to dopamine-induced hypertension after subarachnoid hemorrhage. J Neurosurg 1994; 80:857-64. [PMID: 8169626 DOI: 10.3171/jns.1994.80.5.0857] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of dopamine-induced hypertension on local cerebral blood flow (CBF) were investigated in 13 patients suspected of suffering clinical vasospasm after aneurysmal subarachnoid hemorrhage (SAH). The CBF was measured in multiple vascular territories using xenon-enhanced computerized tomography (CT) with and without dopamine-induced hypertension. A territorial local CBF of 25 ml/100 gm/min or less was used to define ischemia and was identified in nine of the 13 patients. Raising mean arterial blood pressure from 90 +/- 11 mm Hg to 111 +/- 13 mm Hg (p < 0.05) via dopamine administration increased territorial local CBF above the ischemic range in more than 90% of the uninfarcted territories identified on CT while decreasing local CBF in one-third of the nonischemic territories. Overall, the change in local CBF after dopamine-induced hypertension was correlated with resting local CBF at normotension and was unrelated to the change in blood pressure. Of the 13 patients initially suspected of suffering clinical vasospasm, only 54% had identifiable reversible ischemia. The authors conclude that dopamine-induced hypertension is associated with an increase in flow in patients with ischemia after SAH. However, flow changes associated with dopamine-induced hypertension may not be entirely dependent on changes in systemic blood pressure. The direct cerebrovascular effects of dopamine may have important, yet unpredictable, effects on CBF under clinical pathological conditions. Because there is a potential risk of dopamine-induced ischemia, treatment may be best guided by local CBF measurements.
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194
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Linskey ME, Jungreis CA, Yonas H, Hirsch WL, Sekhar LN, Horton JA, Janosky JE. Stroke risk after abrupt internal carotid artery sacrifice: accuracy of preoperative assessment with balloon test occlusion and stable xenon-enhanced CT. AJNR Am J Neuroradiol 1994; 15:829-43. [PMID: 8059649 PMCID: PMC8332190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE To evaluate stable xenon-enhanced CT cerebral blood flow with balloon test occlusion as a predictor of stroke risk in internal carotid artery sacrifice. METHODS Abrupt internal carotid artery occlusion was performed by surgical or endovascular means below the origin of the ophthalmic artery in 31 normotensive patients who were assessed preoperatively by a 15-minute clinical balloon test occlusion followed by an internal carotid artery-occluded xenon CT cerebral blood flow study. RESULTS One patient, who passed the clinical test occlusion but exhibited regions of cerebral blood flow less than 30 mL/100 g per minute on the occlusion xenon CT cerebral blood flow study went on to have a fatal stroke corresponding exactly to the region of reduced blood flow. Thirty patients passed both components of the preoperative stroke-risk assessment. Neuroimaging demonstrated possible flow-related infarctions, which subsequently developed in three patients. Two patients were asymptomatic, and one patient was left with a mild residual hemiparesis. CONCLUSIONS Our protocol provided a statistically significant reduction in subsequent infarction rate and infarction-related death rate when compared with a control group of normotensive abrupt internal carotid artery occlusion patients who did not undergo any preoperative stroke-risk assessment (reported in the literature). The estimated false-negative rate for our preoperative assessment protocol ranged from 3.3% to 10% depending on the assessment of the cause of the three potentially flow-related infarctions. Although life-threatening major vascular territory infarctions have been avoided, our protocol is less sensitive to changes predicting smaller, often minimally symptomatic, vascular border zone infarctions and does not predict postoperative thromboembolic strokes.
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195
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Witt JP, Yonas H, Jungreis C. Cerebral blood flow response pattern during balloon test occlusion of the internal carotid artery. AJNR Am J Neuroradiol 1994; 15:847-56. [PMID: 8059651 PMCID: PMC8332174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE To evaluate the risk of temporary or permanent internal carotid artery occlusion. METHODS In 156 patients intraarterial balloon test occlusion in combination with a stable xenon-enhanced CT cerebral blood flow study was performed before radiologic or surgical treatment. All 156 patients passed the clinical balloon test occlusion and underwent a xenon study in combination with a second balloon test. Quantitative flow data were analyzed for absolute changes as well as changes in symmetry. RESULTS Fourteen patients exhibited reduced flow values between 20 and 30 mL/100 g per minute, an absolute decrease in flow, and significant asymmetry in the middle cerebral artery territory during balloon test occlusion. These patients would be considered at high risk for cerebral infarction if internal carotid artery occlusion were to be performed. With one exception they belonged to a group (class I) of 61 patients who showed bilateral or ipsilateral flow decrease and significant asymmetry with lower flow on the side of occlusion. The other 95 patients, who showed a variety of cerebral blood flow response patterns including ipsilateral or bilateral flow increase, were at moderate (class II) or low (class III) stroke risk. In contrast to these findings, exclusively qualitative flow analysis failed to identify the patients at high risk: a threshold with an asymmetry index of 10% revealed only 16% specificity whereas an asymmetry index of 45% showed only 61% sensitivity for detection of low flow areas (< 30 mL/100 g per minute). CONCLUSION For achieving a minimal hemodynamic related-stroke rate associated with permanent clinical internal carotid artery occlusion we suggest integration of a thorough analysis of quantitative cerebral blood flow data before and during balloon test occlusion.
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196
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Yonas H. Use of xenon and ultrafast CT to measure cerebral blood flow. AJNR Am J Neuroradiol 1994; 15:794-5. [PMID: 8010284 PMCID: PMC8334192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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197
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Horowitz MB, Yonas H, Jungreis C, Hung TK. Management of a giant middle cerebral artery fusiform serpentine aneurysm with distal clip application and retrograde thrombosis: case report and review of the literature. SURGICAL NEUROLOGY 1994; 41:221-5. [PMID: 8146737 DOI: 10.1016/0090-3019(94)90126-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Giant fusiform aneurysms are rare vascular anomalies that due to their size are often difficult to manage. We describe one such aneurysm that was managed with a superficial temporal to middle cerebral artery bypass followed by the application of a single clip just distal to the vascular dilation. Follow-up angiography has shown aneurysm obliteration by the process of retrograde thrombosis.
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198
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Nemoto EM, Klementavicius R, Melick JA, Yonas H. Effect of mild hypothermia on active and basal cerebral oxygen metabolism and blood flow. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1994; 361:469-73. [PMID: 7597971 DOI: 10.1007/978-1-4615-1875-4_84] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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199
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Aggarwal S, Kramer D, Yonas H, Obrist W, Kang Y, Martin M, Policare R. Cerebral hemodynamic and metabolic changes in fulminant hepatic failure: a retrospective study. Hepatology 1994. [PMID: 8276371 DOI: 10.1002/hep.1840190114] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The purpose of this retrospective study was to determine cerebral hemodynamic and metabolic changes in comatose patients with fulminant hepatic failure. Computerized tomography of the brain and cerebral blood flow measurements by the xenon-computerized tomography scan or intravenous xenon-133 methods were obtained in 33 patients with fulminant hepatic failure. In a subgroup of 22 patients, arteriojugular venous oxygen content difference and cerebral metabolic rate for oxygen were determined. Carbon dioxide reactivity was tested in 17 patients, and intracranial pressure was recorded by an epidural monitor in 8 patients. Cerebral blood flow and arteriojugular venous oxygen content difference were adjusted to the average arterial carbon dioxide pressure of the sample (32 mm Hg). Adjusted cerebral blood flow varied from 16.5 to 94.7 ml/100 gm/min; 52% of the patients had reduced adjusted cerebral blood flows (less than 33 ml/100 gm/min), whereas 24% had hyperemic values (greater than 50 ml/100 gm/min). Patients with higher adjusted cerebral blood flows showed cerebral swelling on computerized tomography scan (p < 0.002), were in deeper coma (p < 0.05) and had greater mortality (p < 0.002). The adjusted arteriojugular venous oxygen content difference was negatively correlated with adjusted cerebral blood flow (r = -0.61, p < 0.002). The majority of patients with reduced adjusted cerebral blood flows had low adjusted arteriojugular venous oxygen content differences (less than 5 vol%), indicating hyperemia rather than ischemia. The average cerebral metabolic rate for oxygen was 50% of normal (1.6 +/- 0.4 ml/100 gm/min); even patients with low cerebral metabolic rates for oxygen recovered neurologically.(ABSTRACT TRUNCATED AT 250 WORDS)
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Kalia KK, Yonas H. An aggressive approach to massive middle cerebral artery infarction. ARCHIVES OF NEUROLOGY 1993; 50:1293-7. [PMID: 8257305 DOI: 10.1001/archneur.1993.00540120010005] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE We report favorable outcome after surgical decompression, or strokectomy, guided by xenon-enhanced computed tomographic studies of cerebral blood flow in the setting of potentially fatal swelling from massive cerebral infarction. DESIGN Retrospective analysis with 3 months to 3 years of follow-up. SETTING University of Pittsburgh (Pa) Medical Center, a tertiary care university referral center. PATIENTS Four patients, aged 14 to 46 years, presented with focal neurologic deficits appropriate for a massive middle cerebral artery infarction (two dominant and two nondominant). In spite of medical therapy, all patients deteriorated to at least a decreased level of consciousness. INTERVENTION Using xenon-enhanced computed tomographic studies of cerebral blood flow in three patients, areas of severely ischemic (blood flow, < 5 mL/100 g per minute), nonviable brain were identified and resected. OUTCOME MEASURE Outcome was measured by survival and ability to perform activities of daily living. RESULTS Postoperatively, all patients recovered rapidly (< 6 hours) to the level of function at admission and were able to perform the activities of daily living with minimal or no assistance. CONCLUSION Despite deficits appropriate to the area of infarction, prompt management of life-threatening postinfarction swelling by surgical decompression can yield favorable outcome.
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