A Transdiploic Cerebrospinal Fluid Diversion Device: Potential Use in Intracranial Hypertension Associated with Traumatic Brain Injury

Abstract

Intracranial hypertension (IH) is a critical condition in neurocritical care and needs effective management to avoid severe outcomes like brain herniation and cerebral ischemia. External ventricular drains, although effective in reducing intracranial pressure, pose risks of infection, hemorrhage, and malfunction. This technical note present the transdiploic cerebrospinal fluid (CSF) diversion device, an alternative technique for CSF diversion utilizing the parietal diploic venous system.

Keywords

cerebrospinal fluid diversion - neurotrauma - ventriculostomy - diploic venous system - intracranial hypertension

Introduction

Intracranial hypertension (IH) is considered a severe condition in the neurocritical care field. Appropriate and adequate management of IH to control elevated intracranial pressure (ICP) is essential to prevent brain herniation, cerebral ischemia, and neurological damage and to improve outcomes.[1] An appropriate management of IH is, therefore, paramount to improving patient outcomes.[2] [3] External ventricular drains (EVDs) are used as a strategy to reduce ICP; however, they can be associated with an increased risk of infection, bleeding, and malfunction, delaying patient recovery and increasing morbidity. In this technical note, we elaborate on an alternative method, that is, transdiploic cerebrospinal fluid diversion device (TCFDD), to reduce ICP that can be used in neurotrauma patients who are admitted to neurocritical care settings (see [Fig. 1]).

Fig. 1 Transdiploic cerebrospinal fluid diversion device. 1. Intraventricular catheter. 2. Extracranial device 3. Intradiploic screw.

Pathophysiology of Intracranial Hypertension

It is well known that an imbalance between the production and absorption of cerebrospinal fluid (CSF) or from increased intracranial blood volume, brain edema, or space-occupying lesions can lead to raised ICP/IH. Acute neurological alterations like traumatic brain injury, hydrocephalus, intracerebral hemorrhage, subarachnoid hemorrhage, and malignant stroke can be associated with IH. When ICP rises, IH can increase, and adequate management is relevant to avoid changes in cerebral perfusion that can lead to severe neurological deficits. Traditional ICP management techniques, such as ventriculostomy, are highly invasive, involving the placement of catheters into the brain's ventricular system to drain CSF. Performing ventriculostomy could be associated with complications such as catheter misplacement, brain tissue damage, hemorrhage, and ventriculitis.

The Diploic Venous System

In recent years, the diploic venous system has become a potential alternative route for CSF drainage.[4] [5] [6] The venous channels of Breschet provide a physiological link between the scalp and intracranial circulation, suggesting that they offer a less invasive option for CSF diversion. Preclinical studies have shown that the diploic system can absorb CSF in animal models of hydrocephalus.[7] [8] Some researchers have proposed the use of the diploe for alternative fluid diversion strategies in both chronic and acute settings, although clinical applications remain limited.[7] [8] [9] [10] Based on this anatomical and physiological background, we hypothesize that the diploic system could be effectively leveraged for temporary CSF diversion in the acute management of IH using a device-type screw.

Diploic System and the Proposed

The proposed device is designed to divert CSF through the parietal diploic venous system, providing a safe and temporary means of reducing ICP without requiring direct access to the brain's ventricles. The parietal diploe is a vascularized cancellous bone located between the inner and outer layers of the skull. The diploe (i.e., the spaces of Breschet) are a network of venous channels that connect the superficial veins of the scalp to the intracranial venous system, including the dural venous sinuses. These diploic veins are well developed in the parietal region and present a unique opportunity for CSF drainage, serving as a natural pathway for diverting fluid from the intracranial compartment.

Design and Mechanism of the TCFDD

The TCFDD is focused on physiological foundations well recognized during a ventriculostomy but explicitly designed to engage with the parietal diploe rather than the brain's ventricles. The device consists of a screw-like mechanism that is anchored into the parietal bone, allowing CSF to drain into the diploic venous system and leading to reduced ICP. The device has a hollow central channel through which CSF flows, and a valve mechanism regulates the drainage rate, preventing excessive fluid diversion and maintaining safe ICP levels. The proposed device is intended for short-term use in acute neurocritical conditions where temporary ICP management is necessary. The device can be removable. One advantage of this device is a reduced infection risk in contrast with the primary risks of ventriculostomy, which can have complications like ventriculitis, which can lead to severe complications and prolonged hospital stays. This device offers a prolonged functional duration, which could reduce the need for repeated invasive procedures. This device can be easily removed and converted to conventional shunting.

Conclusion

The diploic venous system can be explored as a temporary solution to address increased ICP and thus as a CSF diversion mechanism, reducing the risk of infection, which improves patient outcomes in the neurocritical care setting. In summary, the proposed TCFDD shall serve as a novel approach to managing IH that will offer a safe and less invasive alternative to conventional ventriculostomy.

Conflict of Interest

None declared.

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Publication History

Article published online:
24 December 2024