Intraoperative Doppler ultrasound of the cavernous part of the internal carotid artery in endoscopic transsphenoidal removal of the laterosellar tumors

The study objective is to describe the technique of intraoperative Doppler ultrasound (DU) of brain arteries and to determine the indications for its use during endoscopic transsphenoidal operations. Materials and methods. The study included 100 patients with skull base tumors (pituitary adenomas, trigeminal schwannomas, chordomas), operated via standard or extended transsphenoid endoscopic approaches. For DU, the location of the internal carotid artery (ICA) relative to the surface of the tumor or dura mater was determined as a red and/or blue color of the monitor screen in the M-mode window, accompanied by a characteristic sound signal. Results. DU was used to remove pituitary adenomas in 95 cases, trigeminal schwannomas in 3 cases, chordomas in 2 cases. Intraoperative DU helped to locate the ICA during removal of the laterosellar part of the tumor in all observations. In none of the cases presented were no injuries to the ICA. Сonclusion. DU is an effective and non-invasive method for detecting ICA during endoscopic operations which contributes to the safe disposal of laterosellar tumors. Adequate use of the method does not carry well-known and potential risks. DU should be performed when the tumor is removed from the cavernous sinus or its projection via the lateral extended transsphenoidal endoscopic access (to determine the safe boundaries of the dura mater section in the cavernous sinus projection).