Vougioukas V I, Coulin C J, Shah M, Berlis A, Hubbe U, Van Velthoven V
Department of Neurosurgery, Albert-Ludwigs University of Freiburg, Freiburg, Germany.
Acta Neurochir (Wien). 2006 Feb;148(2):145-53; discussion 153. doi: 10.1007/s00701-005-0656-6. Epub 2005 Dec 7.
Despite major advances in endovascular embolization techniques, microsurgical resection remains a reliable and effective treatment modality for dural arteriovenous fistulas (DAVF). However, intraoperative detection of these lesions and identification of feeding arteries and draining veins can be challenging. In a series of 6 patients who were not candidates for definitive treatment by endovascular embolization we evaluated the benefits and limitations of computer-assisted image guidance for surgical ablation of DAVF.
Of the 6 patients, 5 presented with haemorrhage and one with seizures. Diagnosis of DAVF was made by conventional angiography and dynamic contrast enhanced MR angiography (CE-MRA). All patients were surgically treated with the assistance of a 3D high resolution T1-weighted MR data set and time-of-flight MR angiography (MRA) obtained for neuronavigation. Registration was based on cranial fiducials and image-guided surgery was performed with the navigation system.
Four of the 6 patients suffered from DAVF draining into the superior sagittal sinus, one fistula drained into paracavernous veins adjacent to the superior petrosal sinus and one patient had a pial fistula draining in the straight sinus. DAVF diagnosed with conventional angiography could be located on CE-MRA and MRA prior to surgery. MRI and MRA images were combined on the neuronavigation workstation and DAVF were located intraoperatively by using a tracking device. In 4 out of 6 cases neuronavigation was used for direct intraoperative identification of DAVF. Brain shift prevented direct tracking of pathological vessels in the other 2 cases, where navigation could only be used to assist craniotomy. Microsurgical dissection and coagulation of the fistulas led to complete cure in all patients as confirmed by angiography.
Neuronavigation may be used as an additional tool for microsurgical treatment of DAVF. However, in this small series of 6 cases, surgical procedures have not been substantially altered by the use of the neuronavigation system. Image guidance has been beneficial for the location of small, superficially located DAVF, whereas a navigated approach to deep-seated lesions was less accurate due to the familiar problem of brain shift and brain retraction during surgery.
尽管血管内栓塞技术取得了重大进展，但显微外科手术切除仍然是治疗硬脑膜动静脉瘘（DAVF）的可靠且有效的治疗方式。然而，术中检测这些病变以及识别供血动脉和引流静脉可能具有挑战性。在一组6例不适合进行血管内栓塞确定性治疗的患者中，我们评估了计算机辅助图像引导在DAVF手术切除中的益处和局限性。
6例患者中，5例表现为出血，1例表现为癫痫发作。通过传统血管造影和动态对比增强磁共振血管造影（CE-MRA）诊断DAVF。所有患者均在用于神经导航的3D高分辨率T1加权磁共振数据集和时间飞跃磁共振血管造影（MRA）的辅助下接受手术治疗。配准基于颅骨基准点，并使用导航系统进行图像引导手术。
6例患者中有4例的DAVF引流至上矢状窦，1例瘘管引流至岩上窦附近的海绵旁静脉，1例患者有软膜瘘管引流至直窦。通过传统血管造影诊断的DAVF在手术前可在CE-MRA和MRA上定位。MRI和MRA图像在神经导航工作站上合并，并且通过使用跟踪设备在术中定位DAVF。6例中有4例在术中使用神经导航直接识别DAVF。脑移位在另外2例中阻止了对病变血管的直接跟踪，在这2例中导航仅用于辅助开颅手术。瘘管的显微外科分离和凝固导致所有患者均完全治愈，血管造影证实了这一点。
神经导航可作为DAVF显微外科治疗的辅助工具。然而，在这一小系列的6例病例中，使用神经导航系统并未使手术操作发生实质性改变。图像引导对于小的、浅表性DAVF的定位有益，而对于深部病变的导航方法由于手术期间常见的脑移位和脑牵拉问题而不太准确。
