Venes J L, Black K L, Latack J T
J Neurosurg. 1986 Mar;64(3):363-70. doi: 10.3171/jns.1986.64.3.0363.
The authors report their recent experience with 14 meningomyelocele patients with the Arnold-Chiari II malformation. Three major types of fourth ventricle anomalies seen in the Arnold-Chiari II malformation are defined, based on preoperative magnetic resonance imaging and intraoperative ultrasound studies. The Type A deformity is defined as no cystic dilatation of the fourth ventricle. In the Type B anomaly, there is intracranial dilatation of the fourth ventricle. The Type C deformity involves intraspinal dilatation of the fourth ventricle, either dorsal to the cord or within the substance of the cord. The Type A deformity was most common in infants, and in two cases progression from a Type A to Type B deformity was documented. Recognition of the type of Arnold-Chiari II malformation aids in designing an operative approach more specific to that structural abnormality. Intraoperative ultrasound is a valuable adjunct in localization of the underlying anomalies and permits safe decompression of the fourth ventricle. The authors' indications for surgery now include failure to thrive due to either early respiratory and swallowing dysfunction, progressive spasticity, or upper-extremity weakness. Nine patients significantly improved following surgery and three patients with a progressively deteriorating course were stabilized by surgery. Decompression of the fourth ventricle by fenestration and internal shunting appears to be well tolerated, even in young infants, and is recommended in the treatment of the Arnold-Chiari II deformity.
作者报告了他们最近对14例患有阿诺德-奇亚里Ⅱ型畸形的脊髓脊膜膨出患者的治疗经验。根据术前磁共振成像和术中超声检查，定义了在阿诺德-奇亚里Ⅱ型畸形中所见的三种主要类型的第四脑室异常。A型畸形定义为第四脑室无囊性扩张。B型异常是指第四脑室在颅内扩张。C型畸形包括第四脑室在脊髓背侧或脊髓实质内的脊髓内扩张。A型畸形在婴儿中最为常见，有两例记录显示从A型畸形进展为B型畸形。识别阿诺德-奇亚里Ⅱ型畸形的类型有助于设计更针对该结构异常的手术方法。术中超声在定位潜在异常方面是一种有价值的辅助手段，并能使第四脑室安全减压。作者目前的手术指征包括因早期呼吸和吞咽功能障碍、进行性痉挛或上肢无力导致的发育不良。9例患者术后明显改善，3例病情逐渐恶化的患者经手术病情稳定。通过开窗和内分流对第四脑室进行减压似乎耐受性良好，即使是在幼儿中也是如此，因此推荐用于治疗阿诺德-奇亚里Ⅱ型畸形。
