Cinalli Giuseppe, Russo Carmela, Vitulli Francesca, Parlato Raffaele Stefano, Spennato Pietro, Imperato Alessia, Quarantelli Mario, Covelli Eugenio, Aliberti Ferdinando
Departments of1Pediatric Neurosurgery.
2Pediatric Neuroradiology, and.
J Neurosurg Pediatr. 2022 Jul 22;30(3):330-341. doi: 10.3171/2022.6.PEDS22171. Print 2022 Sep 1.
The authors' objective was to measure the effect of posterior cranial vault distraction (PCVD) plus foramen magnum decompression (FMD) on dural sinus volume and venous flow in patients with syndromic craniosynostosis.
The volumes of the sagittal, straight, transverse, and sigmoid sinuses of 5 consecutive patients with syndromic craniosynostosis who underwent PCVD+FMD were calculated in cubic centimeters with T2-weighted volumetric MRI sequences before surgery, immediately after surgery, and after the end of the distraction process. Tridimensional reconstructions of phase-contrast magnetic resonance angiography (PC-MRA) images were obtained with multiplanar reconstruction (MPR).
The average total volume of all dural sinuses increased immediately after surgery (from 10.06 cm3 to 12.64 cm3) and continued to increase throughout the 30-day distraction period (from 12.64 cm3 to 14.71 cm3) (p = 0.04), except that the right sigmoid sinus remained stable after the initial increase. The most important increases were observed for the left transverse sinus (+113.2%), right transverse sinus (+104.3%), left sigmoid sinus (+91.3%), and sagittal sinus (+41.8%). Less important modifications were evident for the right sigmoid sinus (+33.7%) and straight sinus (+23.4%). Significant improvements in venous flow were noted on the tridimensional reconstructions of the PC-MRA images. Venous obstruction grading score improved in 4 patients (average [range] 2.4 [ 2-5]) (p = 0.023) and remained stable in 1 patient. All patients had chronic tonsillar herniation (CTH) (mean [range] 16.6 [8-26] mm), and 3 had syringomyelia. CTH showed improvement on the last follow-up MRI evaluation in 4 patients (mean [range] 10.5 [0-25] mm) and worsened from 15 mm to 19 mm in 1 patient. Syringomyelia improved in 2 patients and remained unchanged in 1.
This study has provided the first radiological evidence of the impact of craniofacial surgery on dural sinus anatomy and venous drainage. The venous anomalies described in patients with syndromic craniosynostosis are not static, and PCVD+FMD triggers a dynamic process that can lead to significant modifications of intracranial venous drainage. The traction exerted by the distracted bone flap onto the occipitoparietal dura mater adherent to the inner calvaria may account for the enlargement of the dural sinus throughout the distraction period. The impact of these modifications on venous pressure, intracranial pressure, CTH, and hydrocephalus remains to be determined.
作者的目的是测量后颅穹窿牵张术（PCVD）联合枕大孔减压术（FMD）对综合征性颅缝早闭患者硬脑膜窦容积和静脉血流的影响。
对5例接受PCVD+FMD的综合征性颅缝早闭患者，在手术前、手术后即刻以及牵张过程结束后，使用T2加权容积MRI序列以立方厘米为单位计算矢状窦、直窦、横窦和乙状窦的容积。通过多平面重建（MPR）获得相位对比磁共振血管造影（PC-MRA）图像的三维重建。
所有硬脑膜窦的平均总体积在手术后即刻增加（从10.06 cm³增加到12.64 cm³），并在整个30天的牵张期内持续增加（从12.64 cm³增加到14.71 cm³）（p = 0.04），但右侧乙状窦在最初增加后保持稳定。观察到左侧横窦（+113.2%）、右侧横窦（+104.3%）、左侧乙状窦（+91.3%）和矢状窦（+41.8%）增加最为显著。右侧乙状窦（+33.7%）和直窦（+23.4%）的变化不太明显。在PC-MRA图像的三维重建上，静脉血流有显著改善。4例患者的静脉阻塞分级评分改善（平均[范围]2.4 [2 - 5]）（p = 0.023），1例患者保持稳定。所有患者均有慢性扁桃体疝（CTH）（平均[范围]16.6 [8 - 26] mm），3例有脊髓空洞症。在最后一次随访MRI评估中，4例患者的CTH有所改善（平均[范围]10.5 [0 - 25] mm），1例患者从15 mm恶化至19 mm。2例脊髓空洞症患者病情改善，1例无变化。
本研究提供了颅面外科手术对硬脑膜窦解剖结构和静脉引流影响的首个影像学证据。综合征性颅缝早闭患者中描述的静脉异常并非静态，PCVD+FMD引发了一个动态过程，可导致颅内静脉引流的显著改变。牵张的骨瓣对附着于颅骨内板的枕顶部硬脑膜施加的牵引力可能是整个牵张期硬脑膜窦扩大的原因。这些改变对静脉压、颅内压、CTH和脑积水的影响仍有待确定。
