Lo William B, Thant Kyaw Z, Kaderbhai Jameel, White Nicholas, Nishikawa Hiroshi, Dover Michael Stephen, Evans Martin, Rodrigues Desiderio
Departments of1Neurosurgery and.
2Craniofacial Surgery, Birmingham Children's Hospital, Birmingham, United Kingdom.
J Neurosurg Pediatr. 2020 Jul 10;26(4):421-430. doi: 10.3171/2020.4.PEDS19742. Print 2020 Oct 1.
Children with syndromic, multisuture, and lambdoid craniosynostosis undergoing calvarial surgery often have Chiari malformation type I (CM-I) (or cerebellar tonsillar herniation). The optimal management of this patient group, including the surgical techniques and timing of surgery, remains uncertain. Posterior calvarial distraction (PCD) is an effective method to increase the supratentorial cranial volume and improve raised intracranial pressure in children with complex craniosynostosis. This study investigated the efficacy of PCD in posterior fossa (PF) volume expansion and treatment of CM-I and associated syringomyelia (syrinx) in this group of children.
This retrospective study included patients who were surgically treated between 2006 and 2015. Over 10 years, 16 patients with multisuture synostosis, lambdoid synostosis, or craniosynostosis associated with a confirmed genetic syndrome, and a concurrent CM-I, were included. The mean age at the time of surgery was 5.1 years (range 8 months-18 years). Fourteen patients had pansynostosis and 2 had lambdoid synostosis. Eight had a confirmed syndromic diagnosis (Crouzon in 8, Apert in 4, Pfeiffer in 1, and Saethre-Chotzen in 1). Ten patients had raised intracranial pressure; 4 had syringomyelia.
The average clinical follow-up was 50 months (range 9-116 months). Clinically, 9 patients improved, 7 remained stable, and none deteriorated. The average distraction distance was 23 mm (range 16-28 mm). The PF anterior-posterior (AP) distance/width ratio increased from 0.73 to 0.80 mm (p = 0.0004). Although an osteotomy extending inferior to the torcula (compared with superior) was associated with a larger absolute PF AP distance increase (13 vs 6 mm, p = 0.028), such a difference was not demonstrable when the PF AP distance/width ratio was calculated. Overall, the mean tonsillar herniation improved from 9.3 to 6.0 mm (p = 0.011). Syrinx dimensions also improved in the AP (from 7.9 to 3.1 mm) and superior-inferior (from 203 to 136 mm) dimensions. No patients required further foramen magnum decompression for CM. Of the 16 patients, 2 had subsequent frontoorbital advancement and remodeling, of which 1 was for volume expansion and 1 was for cosmetic purposes. Two patients required CSF shunt insertion after PCD.
Following PCD, PF volume increased as well as supratentorial volume. This morphometric change was observed in osteotomies both inferior and superior to the torcula. The PF volume increase resulted in improvement of cerebellar tonsillar herniation and syrinx. PCD is an efficacious first-line, single-stage treatment for concurrent pansynostosis and lambdoid craniosynostosis, CM-I, and syrinx.
患有综合征性、多缝和人字缝早闭并接受颅骨手术的儿童常伴有I型 Chiari 畸形（CM-I）（或小脑扁桃体疝）。该患者群体的最佳治疗方案，包括手术技术和手术时机，仍不明确。颅骨后路牵张术（PCD）是一种增加幕上颅腔容积并改善复杂颅缝早闭儿童颅内压升高的有效方法。本研究调查了PCD在该组儿童后颅窝（PF）容积扩大以及治疗CM-I和相关脊髓空洞症（空洞）方面的疗效。
这项回顾性研究纳入了2006年至2015年期间接受手术治疗的患者。在10多年间，纳入了16例患有多缝早闭、人字缝早闭或与确诊的遗传综合征相关的颅缝早闭且并发CM-I的患者。手术时的平均年龄为5.1岁（范围8个月至18岁）。14例为全颅缝早闭，2例为人字缝早闭。8例有确诊的综合征诊断（8例为克鲁宗综合征，4例为阿佩尔综合征，1例为 Pfeiffer 综合征，1例为塞特勒-乔岑综合征）。10例患者颅内压升高；4例有脊髓空洞症。
平均临床随访时间为50个月（范围9至116个月）。临床上，9例患者病情改善，7例保持稳定，无患者病情恶化。平均牵张距离为23毫米（范围16至28毫米）。PF前后（AP）距离/宽度比从0.73增加到0.80毫米（p = 0.0004）。尽管向下延伸至窦汇下方（与上方相比）的截骨术与PF AP绝对距离增加更大相关（13毫米对6毫米，p = 0.028），但在计算PF AP距离/宽度比时，这种差异并不明显。总体而言，平均扁桃体疝从9.3毫米改善至6.0毫米（p = 0.011）。空洞尺寸在前后径（从7.9毫米至3.1毫米）和上下径（从203毫米至136毫米）方面也有所改善。没有患者因CM需要进一步进行枕骨大孔减压。16例患者中，2例随后进行了额眶前移和重塑，其中1例是为了扩大容积，1例是为了美容目的。2例患者在PCD后需要插入脑脊液分流管。
PCD后，PF容积以及幕上容积均增加。在窦汇上方和下方的截骨术中均观察到这种形态学变化。PF容积增加导致小脑扁桃体疝和空洞得到改善。PCD是治疗并发全颅缝早闭和人字缝早闭、CM-I和空洞的有效一线单阶段治疗方法。
