Chiari畸形I型的颅颈交界区脑脊液流体力学分型及其手术策略

Classification of Chiari I malformation based on various cerebrospinal fluid flow patterns at the cranial-vertebral junction and selection of surgical procedure

目的分析Chiari畸形I型的颅颈交界区脑脊液流体力学分型、手术策略及其疗效。方法回顾性纳入2008年1月至2015年12月首都医科大学三博脑科医院脊髓脊柱中心收治的126例Chiari畸形I型患者,术前均行颅颈交界区MRI扫描,根据脑脊液流动异常的位置将其分为I型(36例)、II型(48例)及HI型(42例)。术中超声再次探査脑脊液情况决定手术策略,1型患者中,34例采用硬膜下减压术,余2例采用蛛网膜下减压术;U型患者中,36例采用蛛网膜下减压术,余12例采用硬膜下减压术;ID型患者中,40例采用蛛网膜下减压术,余2例采用硬膜下减压术。术后2周,对患者行影像学复査和改良日本骨科协会(mJOA)颈椎评分。对所有患者行临床随访,采用mJOA颈椎评分表评估脊髓空洞相关症状的改善情况,采用芝加哥Chiari成果量表(CCOS)评估术后神经功能恢复情况。结果126例患者的手术均成功。术后无一例出现新发神经功能缺损症状,8例(6.3%)发热,5例(4.0%)发生脑脊液漏,对症治疗后均好转。术后2周,影像学复査显示2例患者(皿型,行蛛网膜下减压术)的脊髓空洞未见明显改善,进一步行脊髓空洞-胸腔分流术后症状改善;126例患者的rnJOA颈椎评分较术前提高[分别为(12.7±2.0)分、(10.7 ±1.6)分,P <0.01]。126例患者的随访时间为(24. 8 ±8.9)个月(12~96个月)。至末次随访,126例患者的mJOA颈椎评分较术前显著提高[(12.8 ± 1.9)分、(10. 7 土1.6)分,P v 0.01 ],但与术后2周间的差异无统计学意义(P = 0.48);CCOS评分与术后2周的差异也无统计学意义[分别为(14.7±1.5)分、(14.4±1.5)分,P=0.576]。结论根据颅颈交界区脑脊液动力学异常将Chiari畸形I型分为3型,1型主要采用硬膜下减压,皿型主要采用蛛网膜下减压型根据减压骨窗的术中超声探查结果判断如何选择减压方式,术后疗效均较好。

Objective To discuss about the classification of Chiari 1 malformation based on different CSF ( cerebrospinal fluid) flow patterns at the cranial-vertebral junction ( CVJ) and to investigate its surgical strategies and outcomes. Methods A total of 126 patients with Chiari I malformation were admitted to Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University from January 2008 to December 2015 and retrospectively enrolled into this study. According to the preoperative findings obtained by using cine phase-contrast MRI (cine PC-MRI) and based on the abnormal CSF flow dynamics at the CVJ, all those patients of Chiari I malformation were classified into 3 patterns: type I (36 cases), type II (48 cases) and type Ⅲ(42 cases). Intraoperative ultrasound to detect cerebrospinal fluid again determined the surgical strategy. In type I patients, 34 patients underwent subdural decompression, and the remaining 2 patients underwent subarachnoid decompression due to cerebrospinal fluid obstruction. In type D patients, 36 patients underwent subarachnoid decompression and the remaining 12 cases underwent subdural decompression. In type ID patients, 40 cases underwent subarachnoid decompression, and the remaining 2 cases underwent subdural decompression due to unobstructed cerebrospinal fluid flow. Two weeks after surgery, the patients underwent an imaging review and assessment based on cervical spine modified Japanese Orthopaedic Association ( mJOA) score. All patients underwent clinical follow-up. The follow-up included the use of the cervical spine mJOA score to assess the improvement of syringomyeliarelated symptoms. The Chicago Chiari Outcome Scale ( CCOS) was used to assess postoperative neurological recovery. Results All 126 patients had successful surgery. There were no cases of new neurological deficits after operation. Eight cases ( 6. 3%) had fever, and 5 cases ( 4. 0%) had cerebrospinal fluid leakage, which improved after symptomatic treatment. Two weeks after surgery, imaging examination showed that there was no significant improvement in syringomyelia in 2 patients ( type Ⅲ, subarachnoid decompression). Further improvement of symptoms was observed after syringomyelia-thoracic shunt. The niJOA score was improved compared with preoperative conditions (12. 7 ± 2. 0 vs. 10. 7 ±1.6, P < 0. 01). The follow-up time of 126 patients was 24. 8 ± 10. 9 months (12 to 96 months). At the last follow-up, the cervial spine mJOA scores of 126 patients were significantly higher than those before surgery ( 12. 8 ± 1.9 rs. 10. 7 ±1.6, P <0. 01), but there was no significant difference when compared with two weeks after surgery (P = 0. 48 ). There was no significant difference in CCOS score compared with 2 weeks post surgery (14. 7 ± 1.5 vs. 14. 4 ± 1.5 , P =0. 576). Conclusions Chiari malformation type I could be classified into 3 subtypes according to cerebrospinal fluid dynamic abnonnalities in the cranial-cervical junction area. Type I is suitable for subdural decompression and type Hl for subarachnoid decompression. In type II , specific decompression methods could be chosen based on intraoperative ultrasound through bone window after craniectomy. The postoperative results seem good.