Department of Spine Surgery, Second Xiangya Hospital of Central South University, 139 Renmin Rd, Changsha, 410011, Hunan, China.
Arch Orthop Trauma Surg. 2012 Nov;132(11):1531-8. doi: 10.1007/s00402-012-1581-9. Epub 2012 Jul 5.
Retrospective case series.
To analyze the causes of conversion to open for the surgical treatment of lumbar disc herniation with use of full endoscopic (FE) technique, and prophylaxis of conversion to open also proposed.
50 patients with lumbar disc herniation underwent discectomy using unilateral portal FE interlaminar approach collected from August 2008 to August 2010. All FE operations were performed under general anesthesia and endotracheal intubation. According to the level incision of the ligament flavum, the starting point of nerve root at the dura under endoscopic view was classified as: Type I (starting point of the nerve root was higher than the incision) and Type II (the starting point of nerve root was lower than the incision). The causes and effective prophylactic measurements for cases of conversion to open were analyzed.
There were 47 cases classified as Type I for a rate of 94 %, and Type II in 3 cases for a rate of 6 %. Five cases were converted to open surgery, and the conversion rate was 10 %. There were three males and two females with a mean age of 36.2 (29-44) years, the average duration of symptoms was 58.4 (35-105) days. The level was L5-S1 in four cases and L4-5 in one, lateral extrusion in three cases, paracentral extrusion in one, and sequestration in one. Leg pain resolved in three cases and improved in two after open surgery. Of five cases of conversion to open, misplacement of the working portal occurred in one case (Type I). Difficult dissection of nerve root and hemostasis resulting in open conversion occurred in one case (Type II); this patient sustained a dural injury. The nerve root could not be exposed in three cases (Type II), the FE changed to open finally. During the open procedure with Type II, we found that the location of origin of the nerve root was caudal to the inferior laminar edge. Therefore, partial removal of bony structures along lateral recess was necessary in order to visualize the nerve root.
Misplacement of working portal during the exposure of the ligament flavum and difficulty in indentifying anatomy are potential causes for conversion to open in the initial adoption of FE technique. However, uncommon conditions such as variation of the nerve root origin can also result in conversion to open in experienced hands. Endoscopic experience, proper patient selection and specific radiographic examination are needed to obtain optimal outcomes using a full endoscopic technique for microdiscectomies.
回顾性病例系列研究。
分析使用全内镜（FE）技术治疗腰椎间盘突出症中转开腹的原因，并提出预防转开腹的措施。
2008 年 8 月至 2010 年 8 月，50 例腰椎间盘突出症患者采用单侧入路 FE 椎板间入路行椎间盘切除术。所有 FE 手术均在全身麻醉和气管插管下进行。根据黄韧带切口的水平，内镜下神经根在硬脊膜下的起始点分为：I 型（神经根起始点高于切口）和 II 型（神经根起始点低于切口）。分析中转开腹的原因及有效预防措施。
47 例为 I 型，占 94%，3 例为 II 型，占 6%。5 例中转开腹，中转率为 10%。其中男 3 例，女 2 例，年龄 36.2（29-44）岁，症状平均持续时间 58.4（35-105）天。4 例病变节段为 L5-S1，1 例为 L4-5，外侧突出 3 例，旁中央突出 1 例，游离型 1 例。3 例术后腿痛缓解，2 例术后改善。5 例中转开腹患者中，1 例（I 型）工作通道定位不当。1 例（II 型）因神经根分离困难和止血导致中转开腹，该患者发生硬脊膜损伤。3 例（II 型）神经根无法显露，最终改行开腹手术。在 II 型开腹手术中，我们发现神经根起始位置在下位椎板边缘下方。因此，为了显露神经根，需要切除侧隐窝外侧的部分骨结构。
在 FE 技术初始应用中，黄韧带暴露时工作通道定位不当和解剖结构难以识别是中转开腹的潜在原因。然而，在经验丰富的术者中，神经根起源的异常等罕见情况也可能导致中转开腹。使用全内镜技术进行微创手术时，需要内镜经验、合适的患者选择和特定的影像学检查，以获得最佳效果。
