强直性脊柱炎颈胸段后凸畸形截骨术后食管长度变化的CT测量及临床意义

Change of esophageal length measured on computed tomography after corrective osteotomy for cervicothoracic kyphosis in patients with ankylosing spondylitis and its clinical significance

目的探讨强直性脊柱炎(AS)颈胸段后凸畸形患者行C7经椎弓根椎体截骨(PSO)后食管长度变化及临床意义。方法回顾性分析2014年12月至2018年11月在南京鼓楼医院接受C7PSO治疗的8例男性AS患者,接受手术时年龄26~49岁,平均(35±7)岁。颈椎侧位X线片上测量术前、术后颈胸段后凸Cobb角、颈胸段矢状面偏移(C2-T1SVA)和固定节段角度(AFL),外观照片上测量颏眉角(CBVA),CT矢状面重建上测量术前、术后截骨椎前缘高度(AHOV)及部分食管长度(食管起始处至下固定椎下终板之间食管长度)。收集Oswestry功能障碍指数(ODI)与颈椎功能障碍指数(NDI)评估患者生存质量,疼痛数字评分表(NRS)评估患者疼痛情况。结果8例患者均获得随访,随访时长3~51个月,平均(15±9)个月。8例患者颈胸段后凸Cobb角平均矫正35.9°±7.3°,C2-T1SVA平均矫正(44.7±11.6)mm,AFL平均矫正32.0°±4.8°,CBVA平均矫正38.1°±11.5°,AHOV平均减少(5.6±1.6)mm,部分食管长度平均延长(15.3±1.6)mm。ODI术前、末次随访分别为(17±14)分、(13±10)分;NDI术前、末次随访分别为(18±15)分、(10±6)分;NRS评分术前为(4.8±2.4)分,末次随访改善至(1.0±1.2)分。食管长度变化与颈胸段后凸Cobb角、C2-T1SVA、AFL、CBVA矫正值存在线性相关(r=0.84、0.83、0.83、0.73,均P<0.05)。结论AS颈胸段后凸畸形患者C7PSO术后食管较术前延长;食管长度变化与矫形效果参数密切相关;手术方案设计时要充分考虑截骨矫形术对食管长度的影响,避免引起相关并发症。

Objective To investigate the change of esophageal length measured on computed tomography after C7 pedicle subtraction osteotomy (PSO) for cervicothoracic kyphosis in ankylosing spondylitis (AS) patients and its clinical significance. Methods Eight male AS patients with cervicothoracic kyphosis, who underwent PSO at C7 level from December 2014 to November 2018 at Nanjing Drum Tower Hospital, were retrospectively reviewed. The mean age was (35±7) years (range, 26-49 years). The cervicothoracic kyphosis, C2-T1 sagittal vertical axis (SVA) and angle of fusion levels (AFL) were measured on lateral cervical radiographs and chin-brow vertical angle (CBVA) was measured on clinical photographs preoperatively and postoperatively. Anterior height of the osteotomized vertebra (AHOV) and esophageal length from the lower endplate of C6 to the inferior endplate of the lower instrumented vertebrae were measured on sagittal plane of reconstructed computed tomography preoperatively and postoperatively. Oswestry Disability Index (ODI), Neck Disability Index (NDI) and Numerical Rating Scale (NRS) were collected to evaluate the clinical outcomes. Results The average follow-up duration was (15±9) months (range, 3-51 months). The average correction of cervicothoracic kyphosis, C2-T1SVA, AFL and CBVA was 35.9°±7.3°,(44.7±11.6) mm, 32.0°±4.8° and 38.1°±11.5°, respectively. The average reduction of AHOV was (5.6±1.6) mm. ODI was improved from 17±14 preoperatively to 13±10 at the final follow-up. The NDI before operation and at the final follow-up was 18±15 and 10±6, respectively. The preoperative NRS was 4.8±2.4, and it decreased to 1.0±1.2 at the final follow-up. The change of esophageal length showed significant correlation with the improvement of cervicothoracic kyphosis, C2-T1SVA, AFL and CBVA(r=0.84, 0.83, 0.83, 0.73, all P<0.05). Conclusions The operation of C7PSO increases esophageal length after cervicothoracic kyphosis in AS patients. The esophageal elongation is closely related with changes of parameters measured on radiographs and clinical photographs. Spine surgeons should be aware of the potential risk of esophagus-related complications caused by esophagus lengthening after C7PSO.