[Transcranial Doppler sonography in radical and function neck dissection].
To evaluate the influence of radical or functional neck dissection on cerebral hemodynamics, pre- and postoperatively TCD sonographic examinations were performed in a group of patients following unilateral radical or bilateral radical/functional neck dissection. Cerebral blood flow velocities (cm/s) and pulsatility index (PI) were studied preoperatively and postoperatively 4, 24 and 48 hours after the operation, using a 2 MHz-pulsed transcranial ultrasonographical system (TCD) with a transtemporal approach to the middle cerebral artery. To exclude the influence of general anaesthesia on cerebral circulation TDC was also performed in a group of patients, following operations under general anaesthesia but not radical nor functional neck dissection. The results of both groups were compared with the data obtained in a control group of healthy persons the same age. The reductions in blood flow velocities and concomitant increases in PI observed during the first postoperative insonation in patients after radical/functional neck dissection reflect a heightened resistance to flow in the arterial cerebral vasculature.