Jellish W S, Martucci J, Blakeman B, Hudson E
Department of Anesthesiology, Loyola University Medical Center, Maywood, IL 60153.
J Cardiothorac Vasc Anesth. 1994 Aug;8(4):398-403. doi: 10.1016/1053-0770(94)90277-1.
Brachial plexus injury after coronary artery bypass grafting (CABG) continues to be a common problem postoperatively. With the use of somatosensory evoked potential monitoring (SSEP), neurologic integrity of the brachial plexus during internal mammary artery (IMA) harvest was assessed and the Rultract and Pittman sternal retractors were compared to determine what effect they had on SSEP characteristics. Results showed that the Rultract and Pittman retractors caused large decreases in SSEP amplitudes after insertion, (1.25 +/- 0.14 versus 0.72 +/- 0.09, P < 0.05; and 1.64 +/- 0.27 versus 0.91 +/- 0.14, P < 0.05) respectively. This decrease was noted in 85% of Rultract and 68.75% of Pittman patients, respectively. Amplitudes increased after retractor removal but never returned to baseline values. Cooley retractor placement in the patients not undergoing IMA harvest (control) produced only mild decreases in amplitude. Waveform latency increased in all groups after retractor placement, but these increases were thought to be clinically insignificant. Postoperatively, three patients in each of the IMA retractor groups had brachial plexus symptoms (18%), whereas only one patient in the control group had symptoms. Somatosensory evoked potential monitoring seems to be a sensitive intraoperative monitor for assessing brachial plexus injury during CABG. The nerve plexus seems to be most at risk for pathologic injury during retraction of the sternum for IMA harvest. Though the Rultract retractor caused greater changes in SSEP characteristics than the Pittman, no clinical outcome differences between the two could be ascertained. Using SSEP monitoring may reduce brachial plexus injury during IMA harvest by allowing early detection of nerve compromise and therapeutic interventions to alleviate the insult while under general anesthesia.
冠状动脉旁路移植术（CABG）后臂丛神经损伤仍是术后常见问题。通过使用体感诱发电位监测（SSEP），评估了在获取乳内动脉（IMA）过程中臂丛神经的神经完整性，并比较了Rultract和Pittman胸骨牵开器，以确定它们对SSEP特征有何影响。结果显示，插入Rultract和Pittman牵开器后，SSEP波幅大幅下降（分别为1.25±0.14对0.72±0.09，P<0.05；以及1.64±0.27对0.91±0.14，P<0.05）。分别在85%的使用Rultract牵开器的患者和68.75%的使用Pittman牵开器的患者中观察到这种下降。牵开器移除后波幅增加，但从未恢复到基线值。在未进行IMA获取的患者（对照组）中放置Cooley牵开器仅使波幅略有下降。牵开器放置后所有组的波形潜伏期均增加，但这些增加被认为在临床上无显著意义。术后，每个IMA牵开器组各有3例患者出现臂丛神经症状（18%），而对照组只有1例患者出现症状。体感诱发电位监测似乎是CABG期间评估臂丛神经损伤的一种敏感的术中监测方法。在为获取IMA而牵开胸骨过程中，神经丛似乎最易发生病理性损伤。尽管Rultract牵开器比Pittman牵开器引起的SSEP特征变化更大，但两者之间未发现临床结果差异。使用SSEP监测可通过在全身麻醉下早期发现神经受压并进行治疗干预以减轻损伤，从而减少IMA获取过程中的臂丛神经损伤。
