Why do bridging veins rupture into the virtual subdural space?

Abstract

SUMMARY Electron microscopic data on human bridging veins show thin walls of variable thickness, circumferential arrangement of collagen fibres and a lack of outer reinforcement by arachnoid trabecules, all contributory to the subdural portion of the vein being more fragile than its subarachnoid portion. These features explain the laceration of veins and the subdural location of resultant haematomas.Most subdural haematomas due to venous bleeding have been attributed to lacerations in bridging veins. These veins form short trunks passing directly from the brain to the dura mater, almost at right angles to both. Between these two points, bridging veins take a straight course with no tortuosity to allow for the possible displacement of brain.' Trotter2 speculated that subdural haematomas are invariably due to trauma tearing large veins, an interpretation elaborated by Krauland.3 According to Leary,4 the common sources of subdural haematomas are ruptured bridging veins, which tend to yield at the arachnoid junction, producing small openings. Yance5 reported two cases of subdural haematoma caused by rupture of bridging veins, and found that the torn veins were occluded by newly formed thrombotic clots. However, little attention has-been given to the laceration mechanism of bridging veins.The cranial ends of bridging veins are firmly fixed to the rigid dura mater, while the cerebral ends are attached to the movable hemisphere. The falx protects the brain from lateral displacement, but there is no protection against antero-posterior movement. Bearing this in mind, Trotter2 speculated that a sharp blow to the front or the back of the head could easily produce a substantial cerebral dislocation, causing the rupture of bridging veins. Leary4 assumed that bridging veins tear easily because their

Abusive head trauma: don’t overlook bridging vein thrombosis

“…In some cases, subdural haematomas appear to be isolated, with no other apparent signs, making diagnosis difficult. We would like to stress the need for careful vertex screening to look for bridging vein thrombosis, which-as some pathologists have pointed out-has high diagnostic value [1].…”

“…They extend, bridge-like, at intervals along the midline, from their attachment to the arachnoid at the medial border of the cerebral hemispheres to the superior sagittal sinus of the dura mater, into which they flow after having traversed the arachnoid space and the deep layers of the dura mater [2]. These veins constitute a short, non-tortuous, perpendicular pipeline between the arachnoid and the dura, making them particularly vulnerable to rupture during anteroposterior movements of the brain within the cranium [1]. In the absence of a clotting disorder, such ruptures lead to thrombosis within a few hours (Fig.…”

Spontan Subdural Hematomu Olan Genç Hasta, Olgu Sunumu

“…Köprü venlerinin özellikle subdural bölgede yırtılmaya meyilli olması, subaraknoid bölgedeki venlere göre daha az kollajen lif içermesine ve içinden geçtiği duranın sert olmasına bağlanmaktadır (15).…”

An asymptotic method for the prediction of the anisotropic effective elastic properties of the cortical vein: superior sagittal sinus junction embedded within a homogenized cell element

“…It is classically associated with head trauma rising from rapid acceleration and/or deceleration that produces the rupture of cortical arteries and most often occurs by tearing of bridging veins (BVs) as they cross from the brain surface to the dural sinus [Maxeiner and Wolff 2002]. Fenderson et al [2007] reported that these veins are prone to rupture at the point of their entry into the SSS, and this was confirmed by the results of microscopy examination [Yamashima and Friede 1984;Vignes et al 2007]. They found that, due to the histological composition of the BVs and the change in the collagen pattern in the vein walls near their entrance into the superior sagittal sinus (SSS), the subdural portion of a BV is more fragile than its subarachnoidal portion.…”

“…They found that, due to the histological composition of the BVs and the change in the collagen pattern in the vein walls near their entrance into the superior sagittal sinus (SSS), the subdural portion of a BV is more fragile than its subarachnoidal portion. The rupture of BVs is induced by the brain-skull relative motion following a head impact as described by neuropathologists [Yamashima and Friede 1984] and by experimental work conducted in vivo [Willinger et al 1995;Ji et al 2004;Bayly et al 2005;Ji and Margulies 2007;Sabet et al 2008].…”