Background. A steady rising trend is observed in the number of carotid surgeries performed. Methods of monitoring of changes in cerebral blood supply used so far, prove inadequate and insufficient. Of special importance and value would be availability of such monitoring during carotid surgery.
Aim of the study. The objective of the current study was evaluation of the applicability and usefulness of a newly devised non-invasive method of Near Infra-Red Transillumination/Backscattering Sounding (NIR-T/BSS) for monitoring of changes in cerebral blood supply in the course of carotid endarterectomy and for assessment of the effectiveness of the surgery, as well as a supplementary diagnostic tool prior to surgical treatment.
Material and methods. NIR-T/BSS recordings were made in 50 patients with recognised carotid stenosis, in whom surgical treatment with carotid endarterectomy was performed.
Results. Application of the NIR-T/BSS method enabled: A. objective assessment of the collateral circulation, B. selection of the sequence of sides to be operated on in cases of equal bilateral carotid stenosis, as determined with Doppler ultrasound, C. monitoring of the changes in cerebral blood supply during the surgery, and D. post-operative evaluation of the beneficial effect of the surgery.  
Conclusions. The early results obtained with the NIR-T/BSS method provide arguments to believe that this method will soon be recognised as highly useful modality in monitoring of the changes in cerebral blood supply. The technique is characterised by high simplicity of use in intra-operative conditions, high sensitivity and congruence of the obtained results with those collected with other methods, as well as with the logic of the physiological reactions. The presented NIR-T/BSS recordings provide qualitative and not quantitative arguments.