经皮内镜椎间孔入路腰椎间盘髓核摘除术学习曲线及其影响因素

A learning curve of percutaneous transforaminal endoscopic discectomy and its contributing factors

目的研究椎间孔入路经皮内镜腰椎间盘髓核摘除术的学习曲线,并分析其主要影响因素。方法 2011年2月至2012年12月,采用椎间孔入路经皮内镜技术治疗100例腰椎间盘突出症,按接受手术先后次序分别纳入5组(A^E组),每组20例,男68例,女32例,平均年龄44岁。突出节段L_(3-4)3例、L_(4-5)节段58例、L_5~S_1节段39例。后外侧突出78例、极外侧突出4例、中央型突出5例、混合型突出13例。合并侧隐窝与椎间孔狭窄15例、突出钙化7例,8例复发性突出,1例融合术后邻近节段突出。手术由具有开展显微内镜腰椎间盘髓核摘除术(MED)8年以上经验的同一组脊柱外科医师完成。对各组手术的通道建立时间、镜下操作时间、射线暴露量以及术后疗效、并发症进行记录、随访和比较。结果 L_(3-4)、L_(4-5)、L_5~S_1各节段平均手术时间分别为(100.33±9.64)min、(106.31±31.01)min、(118.55±29.54.)min。A^E各组总手术时间依次为(152.20±24.48)min、(121.45±21.88)min、(103.30±15.79)min、(88.90±12.93)min、(88.05±17.83)min,D组总手术时间与镜下操作时间均少于前3组(P<0.05),与E组比较差异无统计学意义;C组建立通道时间及透视时间分别为(22.10±4.87)min、(82.45±18.23)s,较前2组均减少(P<0.05),与D组和E组比较差异均无统计学意义(P>0.05)。B组1例硬脊膜撕裂,术后无脑脊液漏;C组1例导丝断裂,D组1例神经根损伤,A组与B组各1例术后一过性神经根痛。从C组开始,术后第1天改良MacNab疗效优良率达到或超过90%。平均随访时间9(1~23)个月,术后1个月腰痛VAS、腿痛VAS、JOA、ODI评分均较术前改善(P<0.01)。A组1例因髓核摘除不足术后3个月行MED,其余病例随访期内无复发与再手术。结论椎间孔入路经皮内镜腰椎间盘髓核摘除术学习曲线较长,通常在60~80例开始达到平台期,镜下操作较通道建立学习曲线更长,穿刺、镜下止血与减压技术的掌握是影响学习曲线的主要因素。

Objective To study the learning curve ofpercutaneous endoscopic lumbar discectomy （ PELD ） via transforaminal approach, and to analyze its main contributing factors. Methods 100 consecutive patients with lumbar disc herniation who received PELD via transforaminal approach from February 2011 to December 2012 were divided into chronological groups （ group A-E ）, with 20 patients in each group. There were 68 males and 32 females, with an average age of 44 years old. Disc protrusion was located at L3-4 in 3 cases, L4-5 in 58 cases and L5-S1 in 39 cases. Posterolateral herniation was in 78 cases, far lateral herniation in 4 cases, central herniation in 5 cases and mixed type herniation in 13 cases. Of 100 cases, there were 15 cases with lateral recess and/or foraminal stenosis, 7 cases with calcified disc herniation, 8 cases with recurrent herniation and 1 case with disc herniation at adjacent segments after fusion surgery. All the operations were performed by the same team of spine surgeons with over 8-year experience of microendoscopic discectomy （ MED ）. The operation time of establishing working channel and endoscopic procedure, as well as the amount of X-ray exposure in each group were recorded. The surgical results and postoperative complications were also evaluated and compared. Results The mean operation time at L3-4, L4-5 and L5-S1 was （ 100.33±9.64 ）, （ 106.31±31.01 ） and （ 118.55±29.54 ） minutes respectively. The mean total operation time in each group （ group A-E ） was （ 152.20±24.48 ）, （ 121.45±-21.88 ）, （ 103.30±15.79 ）, （ 88.90±12.93 ） and （ 88.05±17.83 ） minutes respectively. In group D, the total operation time and the operation time of endoscopic procedure was significantly decreased when compared with that in group A, B and C respectively （ P〈0.05 ）, which was not significantly different from that in group E. The operation time of establishing working channel and the fluoroscopy time was （ 22.10±4.87 ） minutes and （ 82.45±18.23 ） seconds respectively in group C, which was significantly decreased when compared with that in group A and B respectively （ P〈0.05 ）. There was no statistically significant difference in the operation time of establishing working channel and the fluoroscopy time between group D and E （P〉0.05 ）. There was 1 case in group B with dural laceration without cerebrospinal fluid leakage postoperatively, 1 case in group C with guide wire breakage, and 1 case in group D with nerve root injuries. There was 1 case in group A and group B respectively with transient radiculalgia pain postoperatively. The excellent and good rate for clinical results reached at or above 90% according to the modified MacNab criteria from group C on the 1st day postoperatively. All patients were followed up for a mean period of 9 months （ range; 1-23 months ）. The low back pain Visual Analogue Scale （ VAS ）, leg pain VAS, Japanese Orthopedics Association （ JOA ） scale and Oswestry Disability Index （ ODI ） at the 1st month postoperatively were improved respectively when compared with that preoperatively （ P〈0.01 ）. 1 patient in group A received MED 3 months after the surgery due to insufficient discectomy, and there was no recurrence or reoperation for the other cases during the follow-up. Conclusions The learning curve of percutaneous transforaminal endoscopic discectomy is comparatively long. It generally needs 60 to 80 cases of repetitions for a spinal surgeon to be proficient. Endoscopic procedure needs much more repetitions when compared with that establishing working channel does. The main contributing factors to overcome the learning curve include puncture, endoscopic hemostasis and decompression.