Cerebral haemodynamics in internal carotid artery trial occlusion
- 84 Downloads
The purpose of this study was to analyse the cerebral haemodynamic changes brought about by trial occlusion of the internal carotid artery (ICA). Sixteen patients with surgically inaccessible cerebral aneurysms, carotid cavernous fistulas or neck neoplasms were monitored with transcranial Doppler ultrasonography (TCD) during 90–120 s angiographie ICA balloon occlusion or ICA closure with a Selverstone clamp. The blood velocity (V) was registered continuously in both middle cerebral arteries (MCA) while the pulsatility index (PIMCA) and haemodynamic tension (Uhemmca) were calculated.
ICA closure led to an instantaneous drop in the ipsilateral V mca , PI mca and Uhemmca. The V mca thereafter increased gradually until reaching a stable level. The subjects were grouped into those with initial drops in V mca to ≥ 60% of pre-occlusion value (group 1) and those that fell to < 60% (group 2), respectively. In group 1 autoregulatory mechanisms made the PI mca decline further, while the Uhemmca remained unaltered during ICA closure. In group 2, however, the PI mca did not change further, while the Uhemmca increased slightly. The cerebral haemodynamic features during ICA test occlusion were thus essentially different in the two groups. On re-opening the ICA, there was an overshoot in V mca and Uhemmca. Contralaterally, the V mca was increased during ICA occlusion.
Seven of the patients later had their ICA closed permanently. While none of five group 1 patients developed haemodynamic complications, two group 2 individuals experienced haemodynamic stroke. Assuming ICA sacrifice is feasable when test occlusion results in an ipsilateral initial reduction in V mca to ≥ 60% of preocclusion value, the corresponding limit for the Uhemmca is ≥ 40%. In the pre-operative evaluation of the haemodynamic risk related to ICA loss, TCD emerges as a reliable method. It also seems to allow for the reduction of test occlusion time to 90–120 s.
KeywordsTranscranial Doppler ultrasonography balloon occlusion test internal carotid artery cerebral haemodynamics
Unable to display preview. Download preview PDF.
- 4.Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet i: 307–310Google Scholar
- 12.Keller E, Ries F, Grünwald F, Honisch C, Rosanowski F, Pavics L, Herberhold C, Solymosi L (1995) Multimodal carotid test occlusion for evaluation of stroke risk in therapeutic occlusion of the internal carotid artery. Laryngo Rhino Otol 74: 307–311Google Scholar
- 14.Lindegaard K-F, Sorteberg W, Nornes H (1993) Transcranial Doppler in neurosurgery. In: Symonet al (eds) Advances and technical standards in neurosurgery, Vol 20. Springer, Wien New York, pp 64–66Google Scholar
- 16.Murray GD (1989) Confidence intervals. Editorial. Nuc Med Com 10: 387–388Google Scholar
- 18.Ries F, Keller E, Grünwald F, Honisch C, Arnolds R, Rosanowski F, Solymosi L, Kurthen M (1993) Combined haemodynamic assessment and cerebral perfusion measurement in carotid balloon occlusion test. Stroke 24: 500Google Scholar
- 19.Sorteberg W, Lindegaard KF, Rootwelt K, Dahl A, Russel D, Nyberg-Hansen R. Nornes H (1989) Blood velocity and regional blood flow in defined cerebral artery systems. Acta Neurochir (Wien) 97: 47–52Google Scholar
- 20.Sorteberg A, Sorteberg W, Lindegaard K-F, Nornes H (1996) Cerebral haemodynamic considerations in obstructive carotid artery disease. Acta Neurochir (Wien) 138: 68–76Google Scholar
- 22.Tarr RW, Jungreis CA, Horton JA, Petheny S, Sekhar LN, Sen C, Janecka IP, Yonas H (1991) Complications of preoperative balloon test occlusion of the internal carotid arteries: experience in 300 cases. Skull Base Surg 1: 240–244Google Scholar