Department of Neurological Surgery, Aichi Medical University Hospital, Karimata, Yazako, Nagakute City, Aichi, Japan.
Department of Neurological Surgery, Aichi Medical University Hospital, Karimata, Yazako, Nagakute City, Aichi, Japan.
Spine J. 2014 Feb 1;14(2):e7-10. doi: 10.1016/j.spinee.2013.09.022. Epub 2013 Oct 12.
The clinical morphology of a filum terminale arteriovenous fistula (f-AVF) is well known; however, pathological details of the fistulized portion are unknown. Herein, we report the pathological findings of the f-AVF.
Case report and literature review.
To present a detailed pathological examination of the fistulized portion of the f-AVF.
A 71-year-old man presented with gradually worsening bilateral foot paresthesias and anal dysesthesia. T2-weighted magnetic resonance imaging showed flow voids surrounding an edematous conus medullaris and cauda equina with spinal stenosis at L3-L4 and L4-L5. Spinal digital subtraction angiography demonstrated an f-AVF fed by the left T9 intercostal artery.
We performed laminotomies of L3 and L4 to open the dura mater and found a hypertrophic filum terminale. It was resected, leaving a length of 2 cm between the abnormal proximal end and normal distal end. The f-AVF completely disappeared after the surgery. On pathological examination, the filum terminale included two vessels at the proximal end and one at the distal end. At the proximal end, immunostaining showed one vessel that was definitively an artery with both an internal elastic membrane (IEM) and smooth muscle. The other was a vein and lacked an IEM. On the distal side, the collagen fibers gradually increased, the IEM partially disappeared from the arterial wall, and the vein became arterialized with a thin IEM. At the distal end the two vessels joined. Therefore, we speculated that the fistulized portion of the f-AVF was not a fistula point but had some lengths where the artery had characteristics of a vein and there was venous arterialization.
The filum arteriovenous shunting occurred at the portion where there was venous arterialization and the artery had the characteristics of a vein. Therefore, resecting the filum terminale requires more proximal from the normal distal end.
终丝动静脉瘘（f-AVF）的临床形态学众所周知；然而，瘘化部分的病理细节尚不清楚。本文报告了 f-AVF 的病理发现。
病例报告和文献复习。
介绍 f-AVF 瘘化部分的详细病理检查。
一名 71 岁男性出现双侧足部感觉异常和肛门感觉异常进行性加重。T2 加权磁共振成像显示围绕水肿圆锥和马尾的血管流空，L3-L4 和 L4-L5 存在脊髓狭窄。脊柱数字减影血管造影显示 f-AVF 由左侧 T9 肋间动脉供血。
我们进行了 L3 和 L4 的椎板切开术以打开硬脑膜，发现终丝肥大。切除后，异常近端和正常远端之间留有 2cm 的长度。手术后 f-AVF 完全消失。病理检查发现，终丝近端有两条血管，远端有一条血管。在近端，免疫染色显示一条明确的动脉，既有内弹性膜（IEM）又有平滑肌。另一个是静脉，缺乏 IEM。在远端，胶原纤维逐渐增加，动脉壁的 IEM 部分消失，静脉动脉化形成薄的 IEM。在远端，两条血管汇合。因此，我们推测 f-AVF 的瘘化部分不是瘘点，而是有一些动脉具有静脉特征的部位，并且存在静脉动脉化。
动静脉分流发生在静脉动脉化和动脉具有静脉特征的部位。因此，切除终丝需要更靠近正常的远端。
