Murata Shizumasa, Minamide Akihito, Iwasaki Hiroshi, Nakagawa Yukihiro, Hashizume Hiroshi, Yukawa Yasutsugu, Tsutsui Shunji, Takami Masanari, Okada Motohiro, Nagata Keiji, Yoshida Munehito, Schoenfeld Andrew J, Simpson Andrew K, Yamada Hiroshi
1Department of Orthopedic Surgery, Wakayama Medical University, Wakayama.
2Spine Care Center, Wakayama Medical University Kihoku Hospital, Wakayama.
J Neurosurg Spine. 2020 Aug 7;33(6):789-795. doi: 10.3171/2020.5.SPINE20352. Print 2020 Dec 1.
Persistent lumbar foraminal stenosis (LFS) is one of the most common reasons for poor postoperative outcomes and is a major contributor to "failed back surgery syndrome." The authors describe a new surgical strategy for LFS based on anatomical considerations using 3D image fusion with MRI/CT analysis.
A retrospective review was conducted on 78 consecutive patients surgically treated for LFS at the lumbosacral junction (2013-2017). The location and extent of stenosis, including the narrowest site and associated pathology (bone or soft tissue), were measured using 3D image fusion with MRI/CT. Stenosis was defined as medial intervertebral foraminal (MF; inner edge to pedicle center), lateral intervertebral foraminal (LF; pedicle center to outer edge), or extraforaminal (EF; outside the pedicle). Lumbar (low-back pain, leg pain) and patient satisfaction visual analog scale (VAS) scores and Japanese Orthopaedic Association (JOA) scores were evaluated. Surgical outcome was evaluated 2 years postoperatively.
Most instances of stenosis existed outside the pedicle's center (94%), including LF (58%), EF (36%), and MF (6%). In all MF cases, stenosis resulted from soft-tissue structures. The narrowest stenosis sites were localized around the pedicle's outer border. The areas for sufficient nerve decompression were extended in MF+LF (10%), MF+LF+EF (14%), LF+EF (39%), LF (11%), and EF (26%). No iatrogenic pars interarticularis damage occurred. The JOA score was 14.9 ± 2.6 points preoperatively and 22.4 ± 3.5 points at 2 years postoperatively. The JOA recovery rate was 56.0% ± 18.6%. The VAS score (low-back and leg pain) was significantly improved 2 years postoperatively (p < 0.01). According to patients' self-assessment of the minimally invasive surgery, 62 (79.5%) chose "surgery met my expectations" at follow-up. Nine patients (11.5%) selected "I did not improve as much as I had hoped but I would undergo the same surgery for the same outcome."
Most LFS existed outside the pedicle's center and was rarely noted in the pars region. The main regions of stenosis were localized to the pedicle's outer edge. Considering this anatomical distribution of LFS, the authors recommend that lateral fenestration should be the first priority for foraminal decompression. Other surgical options including foraminotomy, total facetectomy, and hemilaminectomy likely require more bone resections than LFS treatment. The microendoscopic surgery results were very good, indicating that this minimally invasive surgery was suitable for treating this disease.
持续性腰椎椎间孔狭窄（LFS）是术后效果不佳的最常见原因之一，也是“腰椎手术失败综合征”的主要促成因素。作者描述了一种基于解剖学考虑的LFS新手术策略，该策略使用MRI/CT分析进行三维图像融合。
对2013年至2017年期间连续接受腰骶部LFS手术治疗的78例患者进行回顾性研究。使用MRI/CT三维图像融合测量狭窄的位置和范围，包括最窄部位及相关病变（骨或软组织）。狭窄定义为椎间孔内侧（MF；内缘至椎弓根中心）、椎间孔外侧（LF；椎弓根中心至外缘）或椎间孔外（EF；椎弓根外侧）。评估腰部（腰痛、腿痛）和患者满意度视觉模拟量表（VAS）评分以及日本骨科协会（JOA）评分。术后2年评估手术效果。
大多数狭窄情况存在于椎弓根中心外侧（94%），包括LF（58%）、EF（36%）和MF（6%）。在所有MF病例中，狭窄由软组织结构导致。最窄的狭窄部位位于椎弓根外缘周围。MF+LF（10%）、MF+LF+EF（14%）、LF+EF（39%）、LF（11%）和EF（26%）区域实现了充分的神经减压。未发生医源性关节突损伤。术前JOA评分为14.9±2.6分，术后2年为22.4±3.5分。JOA恢复率为56.0%±18.6%。术后2年VAS评分（腰痛和腿痛）显著改善（p<0.01）。根据患者对微创手术的自我评估，62例（79.5%）在随访时选择“手术符合我的期望。9例患者（11.5%）选择“我的改善不如预期，但为了相同的结果我会接受相同的手术”。
大多数LFS存在于椎弓根中心外侧，在关节突区域很少见。狭窄的主要区域位于椎弓根外缘。考虑到LFS的这种解剖分布，作者建议外侧开窗应作为椎间孔减压的首要选择。包括椎间孔切开术、全关节突切除术和半椎板切除术在内的其他手术选择可能比LFS治疗需要更多的骨质切除。显微内镜手术结果非常好，表明这种微创手术适合治疗该疾病。
