Hirayama Jiro, Hashimoto Masayuki, Sakamoto Takuya
Department of Orthopaedic and Spine Surgery, Seikei-kai Chiba Medical Center, Chiba, Japan.
J Neurol Surg A Cent Eur Neurosurg. 2020 Jul;81(4):302-309. doi: 10.1055/s-0039-3400752. Epub 2020 Jan 21.
Transforaminal endoscopic lumbar diskectomy (TELD) is a widely used minimally invasive surgical procedure to treat herniated disks. Postoperative dysesthesia (POD) is a significant complication that affects patient satisfaction. Several anatomical and magnetic resonance (MR) imaging studies of the intervertebral foramina showed that TELD should be avoided in patients with small Kambin's triangular working zones. Recently, some reports indicated the usefulness of three-dimensional (3D) computed tomography/magnetic resonance (CT/MR) fusion images. To date, no articles have been published in the English literature regarding the use of 3D CT/MR fusion images before TELD to evaluate Kambin's triangular working zone. Our objective was to examine clinical outcomes when preoperative Kambin's triangular working zone measurements from 3D CT/MR fusion images were used to determine the approach to TELD.
We included 31 patients who underwent TELD. We rotated the 3D CT/MR fusion images from the posteroanterior view on the approach side to the angle at which Kambin's triangular working zone appeared the largest. This was used to determine the intraoperative insertion angle for the working cannula. When the perpendicular line extending from the exiting nerve at the intervertebral disk level to the upper margin of the superior articular process (exiting nerve-superior articular process distance [ESD]) was less than or equal to 7 mm, an approach that combined foraminoplasty with an outside-in technique (F + outside-in) was used. We compared ESD and clinical outcomes, such as POD, between the approaches.
Surgical plans were based on ESD values from 22 patients. ESD was 7 mm in 21 patients, all of whom underwent F + outside-in. The inside-out approach was used in eight of nine patients who did not have ESD measurements. Of these, five patients had retrospective ESD measurements of 7 mm. The mean ESD was 6.3 ± 1.0 mm when inside-out was used and 4.4 ± 1.6 mm when F + outside-in was used, a significant difference. Significant improvements were observed in the visual analog scale scores for low back pain, lower limb pain, and lower limb paresthesia. There were no incidences of POD or intraoperative complications.
Based on preoperative Kambin's triangular working zone measurements from 3D CT/MR fusion images, F + outside-in should be selected when the working zone is smaller than the cannula diameter. This method successfully avoided POD in our study. Preoperative Kambin's triangular working zone measurements from 3D CT/MR fusion imaging can enhance patient safety during TELD.
经椎间孔内镜下腰椎间盘切除术（TELD）是一种广泛应用于治疗椎间盘突出症的微创手术。术后感觉异常（POD）是一种影响患者满意度的重要并发症。多项关于椎间孔的解剖学和磁共振（MR）成像研究表明，对于Kambin三角工作区较小的患者应避免进行TELD。最近，一些报告指出了三维（3D）计算机断层扫描/磁共振（CT/MR）融合图像的实用性。迄今为止，英文文献中尚未发表关于在TELD术前使用3D CT/MR融合图像评估Kambin三角工作区的文章。我们的目的是研究术前通过3D CT/MR融合图像测量Kambin三角工作区来确定TELD手术入路时的临床效果。
我们纳入了31例行TELD的患者。我们将手术入路侧的3D CT/MR融合图像从前后位旋转至Kambin三角工作区显示最大的角度。这用于确定术中工作套管的插入角度。当从椎间盘水平的穿出神经向上关节突上缘延伸的垂线（穿出神经-上关节突距离[ESD]）小于或等于7mm时，采用椎间孔扩大成形术与由外向内技术相结合的入路（F + 由外向内）。我们比较了不同入路的ESD和临床效果，如POD。
手术方案基于22例患者的ESD值制定。21例患者的ESD为7mm，所有这些患者均采用F + 由外向内入路。9例未进行ESD测量的患者中有8例采用了由内向外入路。其中有5例患者的回顾性ESD测量值为7mm。采用由内向外入路时，平均ESD为6.3±1.0mm，采用F + 由外向内入路时为4.4±1.6mm，差异有统计学意义。在腰痛、下肢疼痛和下肢感觉异常的视觉模拟量表评分方面有显著改善。未发生POD或术中并发症。
基于术前通过3D CT/MR融合图像测量的Kambin三角工作区，当工作区小于套管直径时应选择F + 由外向内入路。在我们的研究中，这种方法成功避免了POD。术前通过3D CT/MR融合成像测量Kambin三角工作区可提高TELD期间的患者安全性。
