Letter: the "over the wire" technique for ventricular catheter revision and a proposed access kit for this purpose.

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To the Editor: Accessing the ventricles, via a catheter, either for cerebrospinal fluid diversion procedures (ventriculoperitoneal shunt, ventriculoatrial shunt, external ventricular drain) or for intraventricular drug delivery through port devices, remains one of the most common neurosurgical procedures both in adults and children. For that purpose, the very well known ventricular access kit is being used in standard fashion through a frontal or occipital burr hole. This kit consists of a wall-slitted, blind-ended catheter—the so-called proximal or ventricular catheter—and a sliding stylet with a distal grip (Figure 1).FIGURE 1: The current access kit comprising the wall-slitted, blind-ended ventricular catheter and the stylet with the distal grip.In the common event of proximal catheter failure due to occlusion, infection, or hardware complication,1-5 the neurosurgeon should replace the optimally placed but malfunctioning catheter with a new one, through a revision procedure that is literally identical, in terms of aiming and accessing the ventricular system, with the initial catheter placement. Considering the fact that the risk of initial ventricular catheter misplacement is over 20% according to the literature,6-10 it becomes evident that the revision procedure of already optimally placed but malfunctioning proximal catheters is not free of this complication. In order to simplify and render the above procedure rapid and accurate, we propose the design of a new ventricular catheter and access kit in a way that would be safe and easy to perform an “over the wire” proximal catheter replacement similar to the technique used in the revision of central venous catheters. The proximal tip of the ventricular catheter should be fish-mouthed, open-ended with wall slits (Figures 2 and 3, and the access kit should contain 2 stylets: the first stylet has a bullet-shaped tip (Figure 2), to gently dissect brain parenchyma and access the ventricles, for the initial catheter placement, and the second stylet is calibrated free-ended without the distal grip in the case of a revision procedure (Figure 3). In this way, because both the initial and replacing ventricular catheters are open-ended, they can easily slide along the revision stylet by a procedure similar to the very well known “over the wire” central venous catheter replacement. This specific modification of the ventricular access kit not only simplifies the procedure by making it safe, fast, and easy, but also renders the confirmation postrevision computed tomography unnecessary.FIGURE 2: The open-ended, fish-mouthed new ventricular catheter with the bullet-shaped stylet for the initial placement shown separately and integrated ready for use.FIGURE 3: The plain calibrated catheter for the revision procedure shown alone and with the proposed ventricular catheter sliding along.Disclosure The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.