Chumas P D, Armstrong D C, Drake J M, Kulkarni A V, Hoffman H J, Humphreys R P, Rutka J T, Hendrick E B
Division of Neurosurgery, Hospital for Sick Children, University of Toronto, Ontario, Canada.
J Neurosurg. 1993 Apr;78(4):568-73. doi: 10.3171/jns.1993.78.4.0568.
Although the development of tonsillar herniation (acquired Chiari malformation) in association with lumboperitoneal (LP) shunting is well recognized, it has previously been considered rare. In order to ascertain the incidence of this complication after LP shunting, the authors undertook a retrospective study of all patients in whom this form of shunt had been inserted between 1974 and 1991 at The Hospital for Sick Children, Toronto. In the 143 patients, the mean age at insertion was 3.3 years and the indications for shunt placement were hydrocephalus (81%), pseudotumor cerebri (7%), cerebrospinal fluid fistula (6%), and posterior fossa pseudomeningocele (6%). The mean follow-up period was 5.7 years, during which time there was one shunt-related death due to unsuspected tonsillar herniation. Five other patients developed symptomatic tonsillar herniation treated by suboccipital decompression. Review of all computerized tomography (CT) scans not degraded by artifact showed evidence of excess soft tissue at the level of the foramen magnum in 38 (70%) of 54 patients so studied. In order to confirm that this CT finding represented hindbrain herniation, sagittal and axial magnetic resonance (MR) images were obtained for 17 asymptomatic patients and revealed tonsillar herniation (range 2 to 21 mm) in 12 (70.6%). In addition, some of these asymptomatic patients had evidence of uncal herniation and mesencephalic distortion. Similarities and distinctions are drawn between the morphological changes occurring after LP shunting and those seen in association with the Chiari I and II malformations. Although less than 5% of this study population required treatment for tonsillar herniation, the incidence of this complication was high in asymptomatic patients; MR imaging surveillance for patients with LP shunts is therefore recommended.
虽然扁桃体疝（后天性Chiari畸形）与腰大池-腹腔（LP）分流相关的发展已得到充分认识，但此前一直被认为很罕见。为了确定LP分流术后这种并发症的发生率，作者对1974年至1991年期间在多伦多病童医院接受这种分流术的所有患者进行了一项回顾性研究。在这143例患者中，分流术时的平均年龄为3.3岁，分流放置的指征为脑积水（81%）、假性脑瘤（7%）、脑脊液瘘（6%）和后颅窝假性脑膜膨出（6%）。平均随访期为5.7年，在此期间有1例因未被怀疑的扁桃体疝导致与分流相关的死亡。另外5例患者出现有症状的扁桃体疝，接受了枕下减压治疗。对所有未因伪影而质量下降的计算机断层扫描（CT）进行复查发现，在接受研究的54例患者中有38例（70%）在枕骨大孔水平有软组织过多的证据。为了确认这一CT表现代表后脑疝，对17例无症状患者进行了矢状位和轴位磁共振（MR）成像，结果显示12例（70.6%）有扁桃体疝（范围为2至21毫米）。此外，这些无症状患者中有一些有钩回疝和中脑变形的证据。文中对LP分流术后发生的形态学变化与Chiari I型和II型畸形中所见的变化进行了异同比较。虽然该研究人群中不到5%的患者因扁桃体疝需要治疗，但这种并发症在无症状患者中的发生率很高；因此建议对LP分流患者进行MR成像监测。
