Department of Neurosurgery, University Paris East, Medical School, Assitance Publique - Hôpitaux de Paris, Henri Mondor Hospital, Créteil, France.
Acta Neurochir (Wien). 2012 Jan;154(1):153-9. doi: 10.1007/s00701-011-1136-9. Epub 2011 Sep 3.
External ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks.
The aim of this study was to determine the accuracy of EVD catheter freehand placement.
Pre-operative and post-operative computed tomography scans for 66 consecutive EVDs performed in 56 adult patients (26 men, 30 women) in 2008 were retrospectively reviewed. Etiologies of acute hydrocephalus were subarachnoid or intraventricular haemorrhage (43 cases) or miscellaneous (13 cases). Pre-operative lateral ventricular volume, position of the burr hole, length of the catheter and its sagittal and coronal angular variations from a theoretical trajectory were measured.
The EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51 cc (10-118 cc). The average distance from the burr hole to the midline was 28 mm (10-49 mm) and to the supra-orbital ridge was 101 mm (75-125 mm). The mean intracranial catheter length was 60 mm (from 39-102 mm). Only 50% of the EVDs in the coronal plane and 40% in the sagittal plane were placed with an angular variation of ±5° to the target. The tip was placed outside of the ventricles in three cases; 13 catheters crossed the midline, and five intracranial minor haemorrhages were detected.
Freehand placement of EVDs does not have sufficient accuracy and may lead to drainage dysfunctions. This data suggests that a guidance system for EVD's would be required.
外部脑室引流（EVD）是一种徒手神经外科手术，常规使用解剖学标志进行。
本研究旨在确定 EVD 导管徒手放置的准确性。
回顾性分析 2008 年 56 例成年患者（26 例男性，30 例女性）连续进行的 66 例 EVD 的术前和术后 CT 扫描。急性脑积水的病因是蛛网膜下腔或脑室出血（43 例）或其他原因（13 例）。测量术前侧脑室容积、颅骨钻孔位置、导管长度以及导管矢状面和冠状面与理论轨迹的角度变化。
EVD 放置在右侧（53 例）或左侧（13 例）。术前侧脑室平均容积为 51cc（10-118cc）。颅骨钻孔到中线的平均距离为 28mm（10-49mm），到眶上嵴的距离为 101mm（75-125mm）。颅内导管平均长度为 60mm（39-102mm）。只有 50%的 EVD 在冠状面和 40%在矢状面与目标的角度变化为±5°。有 3 例尖端位于脑室外，13 例导管穿过中线，5 例颅内轻微出血。
EVD 的徒手放置没有足够的准确性，可能导致引流功能障碍。这些数据表明，EVD 需要一个引导系统。
