Journal article
Pressure-flow relations in canine collateral-dependent cerebrum
Stroke (1970), Vol.23(7), pp.988-994
1992
DOI: 10.1161/01.STR.23.7.988
PMID: 1615550
Abstract
Background and Purpose: The pressure-flow relation has been characterized in normal cerebrum, but it has not been studied in cerebrum dependent on collateral flow. The purpose of this investigation was to examine the relation between systemic pressure, regional cerebral blood flow, and middle cerebral artery branch pressure in col lateral-dependent and normal brain. Methods: In 10 anesthetized dogs, we cannulated a branch of the middle cerebral artery and identified collateral-dependent tissues using the shadow flow technique. We measured pressure in normal and cannulated branches of the middle cerebral artery and regional cerebral blood flow. The common carotid arteries were occluded, and hemorrhage reduced mean arterial pressure to 50 and 25 mm Hg. Results: When aortic pressure was 25 mm Hg, blood flow to the collateral-dependent zone decreased from a baseline of 87±5 to 6±1 ml/100 g per minute (mean±SE), and pressure in the cannulated branch of the middle cerebral artery decreased from 49±4 to 2±0.4 mm Hg (p<0.05). Small-vessel resistance in the collateral-dependent region decreased from 0.56±0.09 to 0.38±0.04 mm Hg/ml/100 g per minute (p<0.05) after carotid occlusion but did not change significantly during hypotension. In normal brain, however, small-vessel resistance continued to decrease as systemic pressure was reduced. Conclusions: This study provides pressure-flow relations in normal and collateral-dependent cerebrum during carotid occlusion and progressive hypotension. In collateral-dependent tissue, concurrent occlusion of middle cerebral and carotid arteries produces autoregulatory dilatation of small vessels, resistance fails to decrease as mean arterial pressure is reduced to 25 mm Hg, and profound focal hypo perfusion is produced.
Details
- Title: Subtitle
- Pressure-flow relations in canine collateral-dependent cerebrum
- Creators
- M. G MUHONEN - Univ. Iowa coll. mediicne, veterans administration medical cent., div. neurosurgery, Iowa City IA 52242, United StatesP. D SAWIN - Univ. Iowa coll. mediicne, veterans administration medical cent., div. neurosurgery, Iowa City IA 52242, United StatesC. M LOFTUS - Univ. Iowa coll. mediicne, veterans administration medical cent., div. neurosurgery, Iowa City IA 52242, United StatesD. D HEISTAD - Univ. Iowa coll. mediicne, veterans administration medical cent., div. neurosurgery, Iowa City IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- Stroke (1970), Vol.23(7), pp.988-994
- Publisher
- Lippincott Williams & Wilkins; Hagerstown, MD
- DOI
- 10.1161/01.STR.23.7.988
- PMID
- 1615550
- ISSN
- 0039-2499
- eISSN
- 1524-4628
- Language
- English
- Date published
- 1992
- Academic Unit
- Cardiovascular Medicine; Neuroscience and Pharmacology; Internal Medicine
- Record Identifier
- 9984040561602771
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