Lis Eric, Laufer Ilya, Barzilai Ori, Yamada Yoshiya, Karimi Sasan, McLaughlin Lily, Krol George, Bilsky Mark H
1Department of Radiology, Neuroradiology Service; and.
Departments of2Neurosurgery and.
J Neurosurg Spine. 2018 Oct 19;30(1):111-118. doi: 10.3171/2018.6.SPINE18206. Print 2019 Jan 1.
OBJECTIVEPercutaneous vertebral augmentation procedures such as vertebroplasty and kyphoplasty are often performed in cancer patients to relieve mechanical axial-load pain due to pathological collapse deformities. The collapsed vertebrae in these patients can be associated with varying degrees of spinal canal compromise that can be worsened by kyphoplasty. In this study the authors evaluated changes to the spinal canal, in particular the cross-sectional area of the thecal sac, following balloon kyphoplasty (BKP) prior to stereotactic radiosurgery (SRS).METHODSThe authors retrospectively reviewed the records of all patients with symptomatic vertebral compression fractures caused by metastatic disease who underwent kyphoplasty prior to single-fraction SRS. The pre-BKP cross-sectional image, usually MRI, was compared to the post-BKP CT myelogram required for radiation treatment planning. The cross-sectional area of the thecal sac was calculated pre- and postkyphoplasty, and intraprocedural CT imaging was reviewed for epidural displacement of bone fragments, tumor, or polymethylmethacrylate (PMMA) extravasation. The postkyphoplasty imaging was also evaluated for evidence of fracture progression or fracture reduction.RESULTSAmong 30 consecutive patients, 41 vertebral levels were treated with kyphoplasty, and 24% (10/41) of the augmented levels showed a decreased cross-sectional area of the thecal sac. All 10 of these vertebral levels had preexisting epidural disease and destruction of the posterior vertebral body cortex. No bone fragments were displaced posteriorly. Minor epidural PMMA extravasation occurred in 20% (8/41) of the augmented levels but was present in only 1 of the 10 vertebral segments that showed a decreased cross-sectional area of the thecal sac postkyphoplasty.CONCLUSIONSIn patients with preexisting epidural disease and destruction of the posterior vertebral body cortex who are undergoing BKP for pathological fractures, there is an increased risk of further mass effect upon the thecal sac and the potential to alter the SRS treatment planning.
目的
经皮椎体强化手术，如椎体成形术和后凸成形术，常用于癌症患者，以缓解因病理性塌陷畸形导致的机械性轴向负荷疼痛。这些患者的椎体塌陷可能伴有不同程度的椎管狭窄，而后凸成形术可能会使其恶化。在本研究中，作者评估了立体定向放射外科手术（SRS）前球囊扩张后凸成形术（BKP）对椎管，特别是硬膜囊横截面积的影响。
方法
作者回顾性分析了所有因转移性疾病导致有症状的椎体压缩骨折且在单次分割SRS前接受后凸成形术患者的记录。将BKP前的横断面图像（通常为MRI）与放射治疗计划所需的BKP后CT脊髓造影进行比较。计算后凸成形术前和术后硬膜囊的横截面积，并回顾术中CT成像以观察骨碎片、肿瘤的硬膜外移位或聚甲基丙烯酸甲酯（PMMA）外渗情况。还评估BKP后的成像以观察骨折进展或骨折复位的证据。
结果
在连续30例患者中，41个椎体节段接受了后凸成形术治疗，其中24%（10/41）的强化节段显示硬膜囊横截面积减小。所有这10个椎体节段均存在硬膜外病变和椎体后皮质破坏。没有骨碎片向后移位。20%（8/41）的强化节段发生了轻微的硬膜外PMMA外渗，但在BKP后硬膜囊横截面积减小的10个椎体节段中，只有1个节段出现了这种情况。
结论
对于因病理性骨折接受BKP且已有硬膜外病变和椎体后皮质破坏的患者，硬膜囊受到进一步占位效应的风险增加，并且可能会改变SRS治疗计划。
