Abstract
BACKGROUND AND PURPOSE: Endovascular brain cooling as a method for rapid and selective induction of hypothermic neuroprotection has not been systematically studied in humans. In this clinical pilot study we investigated the feasibility, safety, and physiologic responses of short-term brain cooling with IC-CSI.
MATERIALS AND METHODS: We studied 18 patients (50 ± 10 years old, 9 women) undergoing follow-up cerebral angiography after previous treatment of vascular malformations. Isotonic saline (4–17°C) was infused into 1 internal carotid artery at 33 mL/min for 10 minutes. Brain (JVB) and bladder/esophageal temperature measurements (n = 9) were performed. Both MCAs were monitored with transcranial Doppler sonography (n = 13). Arterial and JV blood were sampled to estimate hemodilution and brain oxygen extraction.
RESULTS: JVB temperature dropped ∼0.84 ± 0.13°C and systemic temperature by 0.15 ± 0.08°C from baseline (JVB versus systemic temperature: P = .0006). Systolic MCA-flow velocities decreased from 101 ± 27 to 73 ± 18 cm/s on the infused side and from 83 ± 24 to 78 ± 21 cm/s on the contralateral side (relative changes, −26 ± 8% versus −4 ± 27%; P = .009). Changes in hematocrit (−1.2 ± 1.1%) and cerebral arteriovenous oxygen difference (0.2 ± 1.0 mL O2/100 mL) were not significant. Doppler data showed no signs of vascular spasm or microemboli. No focal neurologic deficits occurred. Pain was not reported.
CONCLUSIONS: The results of this pilot study suggest that brain cooling can be achieved safely, rapidly, and selectively by means of IC-CSI, opening a new potential avenue for acute neuroprotection. Clinical investigations with control of infusion parameters and measurements of CBF, oxygen consumption, and brain temperature are warranted.
Abbreviations
- ABC
- automated blood count
- AComA
- anterior communicating artery
- AVM
- arteriovenous malformation
- BA
- basilar artery
- BMR
- basal metabolic rate
- CBF
- cerebral blood flow
- ΔA-V
- difference between arterial and venous oxygen content
- FV
- flow velocity
- IA
- intra-arterial
- ICA
- internal carotid artery
- IC-CSI
- intracarotid cold saline infusion
- JV
- jugular vein
- JVB
- jugular venous bulb
- JVBT
- jugular venous bulb temperature
- MCA
- middle cerebral artery
- MES
- microemboli signals
- N/A
- not available
- O2-Sat
- oxygen saturation
- PI
- pulsatility index
- PICA
- posterior inferior cerebral artery
- TCD
- transcranial Doppler
- Copyright © American Society of Neuroradiology
Indicates open access to non-subscribers at www.ajnr.org