Sangwanloy Prawit, Vaniyapong Tanat, Norasetthada Thunya, Jetjumnong Chumpon
Clinical Surgical Research Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Neurosurgery Unit, Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Clinical Surgical Research Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Neurosurgery Unit, Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Clin Neurol Neurosurg. 2022 May;216:107214. doi: 10.1016/j.clineuro.2022.107214. Epub 2022 Mar 19.
A significant number of patients with Chiari type 1 malformation (CM1) have abnormal clivo-axial angle (CXA) without other radiographic indicators of basilar invagination or craniovertebral junction (CVJ) instability. This study aimed to investigate whether abnormal CXA alone influences postoperative outcomes among patients who underwent foramen magnum decompression (FMD).
A total of 44 adult patients with symptomatic CM1 undergoing FMD without CVJ fixation were enrolled. Preoperative clinical characteristics and radiographic measurement include the CXA as well as the radiographic indicators of basilar invagination and instability were recorded. The univariate and multivariate binary logistic regression tests were used to identify the potential prognostic factors for favorable outcomes.
Eighteen patients (41%) and 26 patients (59%) were divided into unfavorable and favorable outcome groups, respectively. Baseline demographic and imaging characteristics were similar between the two patient groups. The mean CXA was 132.3 ± 15.8 and 145 ± 13.6 degrees in the unfavorable and favorable groups, respectively (P = 0.091). In the favorable outcome group, the proportion of patients with CXA > 135 degrees was significantly higher than that of the unfavorable outcome group (77% vs. 44%; P = 0.05). The CXA > 135 degrees was found to be the only independent predictor associated with favorable outcomes (adjusted risk ratio 2.16; 95% CI 1.01-4.76; P = 0.047).
The preoperative CXA of greater than 135 degrees was identified as a prognostic factor associated with a favorable outcome at one-year follow-up after FMD among adult patients with symptomatic CM1 without basilar invagination or CVJ instability. This factor should be incorporated into preoperative considerations.
相当数量的 Chiari 1 型畸形（CM1）患者存在斜坡-枢椎角（CXA）异常，且无其他基底凹陷或颅颈交界区（CVJ）不稳定的影像学指标。本研究旨在调查单纯 CXA 异常是否会影响接受枕骨大孔减压术（FMD）患者的术后结局。
共纳入 44 例有症状的 CM1 成年患者，他们接受了 FMD 但未进行 CVJ 固定。记录术前临床特征和影像学测量结果，包括 CXA 以及基底凹陷和不稳定的影像学指标。采用单因素和多因素二元逻辑回归检验来确定良好结局的潜在预后因素。
18 例患者（41%）和 26 例患者（59%）分别被分为不良结局组和良好结局组。两组患者的基线人口统计学和影像学特征相似。不良结局组和良好结局组的平均 CXA 分别为 132.3±15.8 度和 145±13.6 度（P = 0.091）。在良好结局组中，CXA>135 度的患者比例显著高于不良结局组（77%对 44%；P = 0.05）。发现 CXA>135 度是与良好结局相关的唯一独立预测因素（调整风险比 2.16；95%CI 1.01 - 4.76；P = 0.047）。
术前 CXA 大于 135 度被确定为在 FMD 术后一年随访时，有症状的 CM1 成年患者且无基底凹陷或 CVJ 不稳定的良好结局的预后因素。该因素应纳入术前考虑。
