Pearce H J, Becchetti J J, Brown H J
Surgery. 1980 Mar;87(3):339-42.
Photoplethysmograph (PPG) has added a new dimension of safety to carotid endarterectomy operations. Used to monitor adequate shunt blood flow during carotid endarterectomy, the PPG has proven to be a sensitive, reliable, and accurate device. Temporary intraoperative shunt occlusion is immediately indicated by marked amplitude reductions in the supraorbital artery pulse waveform. The cause of the occlusion is usually found to be impingment of the distal end of the shunt against the arterial wall, which is easily corrected by proximal positioning of the shunt. Also, occasionally occlusion will occur from kinking of the internal carotid artery distal to the shunt, which is corrected by slight proximal retraction on the artery. Repositioning retractors in the upper extent of the operative field will alleviate any occlusions from retractor pressure on the internal carotid artery. Without a method of sensing hemodynamically significant decreases in shunt flow during operation for carotid endarterectomy, there exists a risk of prolonged unrecognized intraoperative cerebral ischemia.
光电容积脉搏波描记术（PPG）为颈动脉内膜切除术增添了新的安全维度。PPG用于在颈动脉内膜切除术中监测分流血流量是否充足，已被证明是一种灵敏、可靠且准确的设备。术中临时分流闭塞可通过眶上动脉脉搏波形的明显幅度降低立即显示出来。闭塞的原因通常是分流远端撞击动脉壁，通过将分流近端重新定位可轻松纠正。此外，偶尔分流远端的颈内动脉扭结也会导致闭塞，通过对动脉进行轻微近端牵拉可纠正。在手术区域上部重新放置牵开器将缓解因牵开器对颈内动脉的压力导致的任何闭塞。在颈动脉内膜切除术的手术过程中，如果没有一种方法来检测分流血流量的血流动力学显著降低，就存在术中脑缺血长时间未被识别的风险。
