THERMAL-DIFFUSION BLOOD-FLOW MONITORING DURING ANEURYSM SURGERY

Cortical blood flow (CoBF) monitoring with a thermal diffusion flow pr obe was performed during the clipping of aneurysms of the ICA and MCA regions, on a series of patients during the acute stage of subarachnoi d haemorrhage. Emphasis was placed on the CoBF recovery after temporar y clip release. Since the absolute value in this technique is unreliab le, recovery of blood flow after temporary clipping is represented as %CoBF according to the following equation: %CoBF recovery = (CoBFpost- CoBFintra)/(CoBFpre-CoBFintra) Presumably, this parameter checks the p atency of the concerned cerebral vessels during clipping and/or releas e. Percent recovery of more than 100%, indicating postischaemic reacti ve hyperaemia, was observed immediately after release of the temporary clips in 8 of the 9 cases evaluated. In one case, with prolonged temp orary clipping (37 min), no immediate recovery was observed after clip release, suggesting no-reflow phenomenon. The value slowly recovered after local administration of papaverin and returned to the pre-occlus ion level within 20 minutes. Thermal diffusion CoBF monitoring may be useful in detecting the possible no-reflow phenomenon, that may lead t o ischaemic complication, even after successful aneurysm clipping.