1Division of Neurosurgery, Department of Surgery, Medical School, Federal University of Goiás.
2Neurosurgery Service, Araújo Jorge Cancer Hospital; and.
J Neurosurg. 2021 Oct 22;136(4):1128-1138. doi: 10.3171/2021.6.JNS21709. Print 2022 Apr 1.
One of the few resources for treating medically intractable pain is ablative surgery, but its indications have fallen dramatically over the last decades. One such procedure is mesencephalotomy. This study aims to determine current risks and benefits of MR-guided semidirect targeting-based stereotactic mesencephalotomy.
This was a retrospective study based on a review of the medical records of 22 patients with nociceptive (n = 5), neuropathic (n = 10), or mixed (n = 7) refractory pain treated with unilateral mesencephalotomy alone (17 patients) or associated with bilateral anterior cingulotomy (5 patients) between 2014 and 2021 in the authors' institutions. The confidence interval adopted in this study was 95%.
The sample included 12 women and 10 men with ages ranging from 23 to 80 years (mean 55.1 ± 17.1 years). Using MR-guided semidirect targeting, the following structures were targeted: spinoreticulothalamic (neuropathic/mixed pain, n = 17), trigeminothalamic (nociceptive/mixed pain in the face, n = 5), and neospinothalamic (nociceptive/mixed pain in the body, n = 7) pathways. The most common response to macrostimulation was central heat/moderate discomfort. Radiofrequency thermocoagulation was made with 70°C-75°C/60 sec. A total of 86.3% (3 months) and 76.9% (12 months) of the patients achieved excellent or good results (improvement of pain > 50%), presenting with a significant mean pain relief of 80.1% at 3 months and 71.4% at 12 months postoperatively. The addition of bilateral anterior cingulotomy did not improve the results. Patients with upper limb, cervicobrachial, and face pain did significantly better than those with trunk pain. The worst results were seen in patients with neuropathic and/or trunk pain. The surgical failure (pain relief ≤ 25%) and recurrence rates were 9.1% each, apparently related to the use of lower lesioning parameters (70°C/60 sec) and to the presence of neuropathic and/or trunk pain. The morbidity rate was 8%, with both complications (vertical diplopia and confusion/agitation) happening in patients lesioned with 75°C/60 sec. There were no deaths in this series.
These results show that contemporary stereotactic mesencephalotomy is an effective, relatively low-risk, and probably underused procedure for treating medically intractable pain. Careful semidirect determination of the target coordinates associated with close attention to electrical macrostimulation responses certainly plays an important role in avoiding complications in most of the procedures. A higher lesioning temperature (75°C) apparently prevents recurrence, but at the cost of an increased risk of complications.
治疗医学上难以控制的疼痛的少数资源之一是消融手术，但在过去几十年中，其适应证显著下降。其中一种手术是中脑切开术。本研究旨在确定基于磁共振引导的半直接靶向的立体定向中脑切开术的当前风险和益处。
这是一项回顾性研究，基于对 2014 年至 2021 年期间在作者所在机构接受单侧中脑切开术（17 例）或单侧中脑切开术联合双侧前扣带切开术（5 例）治疗的 22 例患有疼痛性（n=5）、神经性（n=10）或混合性（n=7）难治性疼痛的患者的病历进行回顾。本研究采用的置信区间为 95%。
样本包括 12 名女性和 10 名男性，年龄 23 至 80 岁（平均 55.1±17.1 岁）。使用磁共振引导的半直接靶向，针对以下结构：脊髓网状丘脑（神经性/混合性疼痛，n=17）、三叉神经丘脑（面部疼痛，疼痛性/混合性，n=5）和新脊髓丘脑（躯体疼痛，疼痛性/混合性，n=7）通路。最常见的对宏观刺激的反应是中央热/中度不适。射频热凝采用 70°C-75°C/60 秒。术后 3 个月和 12 个月时，86.3%（3 个月）和 76.9%（12 个月）的患者达到了极好或良好的结果（疼痛改善>50%），术后 3 个月疼痛缓解率为 80.1%，12 个月时为 71.4%。双侧前扣带切开术的加入并没有改善结果。上肢、颈臂和面部疼痛的患者明显优于躯干疼痛的患者。神经源性和/或躯干疼痛患者的结果最差。手术失败（疼痛缓解≤25%）和复发率均为 9.1%，显然与较低的病变参数（70°C/60 秒）的使用以及神经源性和/或躯干疼痛的存在有关。发病率为 8%，并发症（垂直复视和意识混乱/激动）发生在 75°C/60 秒病变的患者中。本系列中无死亡病例。
这些结果表明，当代立体定向中脑切开术是一种有效、相对低风险且可能未被充分利用的治疗医学上难以控制的疼痛的方法。仔细的半直接确定目标坐标并密切注意电宏观刺激反应肯定在大多数手术中避免并发症方面发挥了重要作用。较高的病变温度（75°C）显然可以预防复发，但代价是并发症风险增加。
