Lind Göran, Meyerson Björn A, Winter Jaleh, Linderoth Bengt
Department of Neurosurgery, Karolinska Hospital, Stockholm, Sweden.
Neurosurgery. 2003 Nov;53(5):1150-3; discussion 1153-4. doi: 10.1227/01.neu.0000089107.67673.71.
To optimize the technique of implanting laminotomy plate electrodes for spinal cord stimulation and to minimize the discomfort of the patients during surgery. This operation is often performed while the patient is under local anesthesia, which is very stressful for the patient, or under general anesthesia, which precludes the use of test stimulation. An alternative approach is to perform the implantation with a spinal anesthetic and to examine whether stimulation-induced paresthesiae can still be evoked to guide the positioning of the electrode.
Spinal anesthesia was induced by bupivacaine (12.5-20 mg), which produced complete motor block and anesthesia up to a midthoracic level. After a single-level laminotomy (thoracic vertebrae 9-11) a four-pole plate electrode was inserted into the epidural space. Stimulation was applied with commonly used parameters, and the electrode was positioned so that the paresthesiae covered the painful region.
In 19 patients (20 procedures) with different forms of neuropathic pain, implantation of laminotomy plate electrodes could be performed under spinal anesthesia without problems. In all patients, it was possible to evoke paresthesiae, the distribution of which could be reproduced postoperatively. The paresthesia thresholds during surgery were only moderately higher than those recorded after implantation (mean, 3.1 versus 2.1 V, respectively). During an interview after the intervention, no patient reported that he or she had experienced surgery as painful or uncomfortable.
Implantation of laminotomy electrodes can be performed conveniently with spinal anesthesia because it minimizes discomfort for the patient and enables the use of intraoperative test stimulation to guide the positioning of the electrode. In spite of the total motor block and anesthesia, paresthesiae representing the activation of the dorsal columns can be evoked and are well perceived, and the thresholds are not abnormally high. This observation supports the notion that the subarachnoidal anesthetic agent acts predominantly on the spinal rootlets rather than on the spinal afferent pathways.
优化用于脊髓刺激的椎板切开术极板电极植入技术，并尽量减少患者手术期间的不适。该手术通常在患者局部麻醉下进行，这对患者来说压力很大，或者在全身麻醉下进行，而全身麻醉会妨碍使用测试刺激。另一种方法是在脊髓麻醉下进行植入，并检查是否仍能诱发刺激引起的感觉异常以指导电极定位。
用布比卡因（12.5 - 20毫克）诱导脊髓麻醉，其产生完全运动阻滞和高达胸中段水平的麻醉。在进行单节段椎板切开术（第9 - 11胸椎）后，将四极板电极插入硬膜外间隙。以常用参数施加刺激，并将电极定位，使感觉异常覆盖疼痛区域。
在19例（20次手术）患有不同形式神经病理性疼痛的患者中，可在脊髓麻醉下顺利进行椎板切开术极板电极植入。在所有患者中，都能诱发感觉异常，其分布在术后可重现。手术期间的感觉异常阈值仅略高于植入后记录的阈值（分别为平均3.1伏和2.1伏）。在干预后的访谈中，没有患者报告经历过疼痛或不适的手术。
椎板切开术电极植入可在脊髓麻醉下方便地进行，因为它能将患者的不适降至最低，并能利用术中测试刺激来指导电极定位。尽管存在完全运动阻滞和麻醉，但仍可诱发代表背柱激活的感觉异常，且能被很好地感知，阈值也没有异常升高。这一观察结果支持了蛛网膜下麻醉剂主要作用于脊髓小根而非脊髓传入通路的观点。
