Chiari malformation type I (CM-I) is frequent in children and remains a surgical challenge. Several techniques have been described for posterior fossa decompression. No decision algorithm has been validated, and strategies are highly variable between institutions. The goal of this study was to define therapeutic guidelines that take into consideration patient specificities.

The authors retrospectively collected data from patients who were < 18 years of age, were diagnosed with CM-I, and were treated surgically between 2008 and 2018 in 8 French pediatric neurosurgical centers. Data on clinical features, morphological parameters, and surgical techniques were collected. Clinical outcomes at 3 and 12 months after surgery were assessed by the Chicago Chiari Outcome Scale. The authors used a hierarchical clustering method to define clusters of patients by considering their anatomical similarities, and then compared outcomes between surgical strategies in each of these clusters.

Data from 255 patients were collected. The mean age at surgery was 9.6 ± 5.0 years, syringomyelia was reported in 60.2% of patients, the dura mater was opened in 65.0% of patients, and 17.3% of patients underwent a redo surgery for additional treatment. The mean Chicago Chiari Outcome Scale score was 14.4 ± 1.5 at 3 months (n = 211) and 14.6 ± 1.9 at 12 months (n = 157). The hierarchical clustering method identified three subgroups with potentially distinct mechanisms underlying tonsillar herniation: bony compression, basilar invagination, and foramen magnum obstruction. Each cluster matched with specific outcomes.

This French multicenter retrospective cohort study enabled the identification of three subgroups among pediatric patients who underwent surgery for CM-I, each of which was associated with specific outcomes. This morphological classification of patients might help in understanding the underlying mechanisms and providing personalized treatment.

Chiari 畸形 I 型 (CM-I) 在儿童中很常见，并且仍然是一项手术挑战。已经描述了几种用于后颅窝减压的技术。没有决策算法得到验证，机构之间的策略差异很大。本研究的目的是确定考虑到患者特异性的治疗指南。

作者回顾性收集了 2008 年至 2018 年期间在 8 个法国儿科神经外科中心被诊断为 CM-I 并接受手术治疗的 18 岁以下患者的数据。收集了有关临床特征、形态学参数和手术技术的数据。手术后 3 个月和 12 个月的临床结果由芝加哥 Chiari 结果量表评估。作者使用分层聚类方法通过考虑患者的解剖相似性来定义患者集群，然后比较每个集群中手术策略的结果。

收集了 255 名患者的数据。手术的平均年龄为 9.6 ± 5.0 岁，据报道有 60.2% 的患者出现脊髓空洞症，65.0% 的患者打开了硬脑膜，17.3% 的患者接受了重做手术以进行额外治疗。平均芝加哥 Chiari 结果量表评分在 3 个月时为 14.4 ± 1.5 (n = 211)，在 12 个月时为 14.6 ± 1.9 (n = 157)。层次聚类方法确定了三个潜在的扁桃体突出的不同机制的亚组：骨压缩、基底内陷和枕骨大孔阻塞。每个集群都与特定结果相匹配。

这项法国多中心回顾性队列研究能够在接受 CM-I 手术的儿科患者中识别出三个亚组，每个亚组都与特定结果相关。这种患者的形态学分类可能有助于了解潜在机制并提供个性化治疗。