Elias Z, Powers S K, Bullitt E
Division of Neurological Surgery, University of North Carolina, Chapel Hill.
Appl Neurophysiol. 1988;51(2-5):255-63. doi: 10.1159/000099970.
The current study was designed to measure and compare the size of dorsal root entry zone lesions made in the midthoracic spinal cord of anesthetized cats with a carbon dioxide laser and the radiofrequency (RF) probe utilizing currently employed clinical parameters. Cats were monitored intraoperatively with somatosensory evoked potentials (SSEPs) derived from stimulation of the ipsilateral posterior tibial nerve in order to assess the acute effect of lesion production on function within the ipsilateral dorsal column. Daily postoperative neurologic evaluations were recorded. The lesioned segments of spinal cord from sacrificed animals were examined histologically to determine the extent of cord injury at 1 and 30 days. SSEPs remained normal for the laser group, but were uniformly attenuated or lost in the RF group. Neurologically, the laser group fared better, with only a mild transient monoparesis, compared to a persistent moderate paraparesis for the RF group. On histologic examination, the depths of the laser and electrode lesions were similar, but the RF lesions showed more lateral spread. Laser lesions comprised 4.4 +/- 1.6% of the cross-sectional area of the spinal cord whereas the RF lesions occupied 22.8 +/- 4%. These findings demonstrate that at the parameters employed, the carbon dioxide laser produces smaller lesions than does the RF electrode.
本研究旨在利用当前使用的临床参数，测量并比较使用二氧化碳激光和射频（RF）探头在麻醉猫的胸段脊髓中部制造的背根入髓区损伤的大小。术中通过刺激同侧胫后神经获得体感诱发电位（SSEP）来监测猫，以评估损伤产生对同侧背柱内功能的急性影响。记录术后每日的神经学评估结果。对处死动物的脊髓损伤节段进行组织学检查，以确定术后1天和30天时脊髓损伤的程度。激光组的SSEP保持正常，而射频组的SSEP均减弱或消失。在神经学方面，激光组情况较好，仅有轻度短暂性单瘫，而射频组则持续存在中度截瘫。组织学检查显示，激光和电极损伤的深度相似，但射频损伤的横向扩散更明显。激光损伤占脊髓横截面积的4.4±1.6%，而射频损伤占22.8±4%。这些发现表明，在所采用的参数下，二氧化碳激光产生的损伤比射频电极小。
