Article

Microsurgical and histomorphometric study of the occipital sinus: quantitative measurements using a novel approach of stereology.

Department of Neurosurgery, Göztepe Education and Research Hospital, Kadiköy, Istanbul, Turkey.
Clinical Anatomy (Impact Factor: 1.16). 03/2010; 23(4):386-93. DOI: 10.1002/ca.20947
Source: PubMed

ABSTRACT Quantitative descriptions of the occipital sinus are lacking in the extant medical literature. Posterior fossa duras with the superior sagittal sinus, the inferior and superior petrosal sinuses were dissected and taken out from fresh human cadavers by cutting at the superior sagittal sinus, the marginal sinuses and the petrosal sinuses bilaterally. The length of the occipital sinuses was measured using calipers. A 0.5-cm section of the occipital sinus was cut out at its midpoint and prepared for measurements of the perimeter and diameter using a stereology workstation. The sinuses were also examined qualitatively using a surgical microscope. There was no occipital sinus in 6.6% of total 30 cases. Multiple occipital sinuses were seen in 10%. In one specimen, the sinus seemed incomplete, failing to reach the marginal sinuses. Some specimens gave the impression that more than one occipital sinus was present, nevertheless, careful dissection showed connections. The breadth of the sinus steadily narrowed downward in direction of foramen magnum. The inner wall with many fibrous bridges was tight, except the lateral parts that were easily separated into two dural sheets. The length of the sinus varied from 10 to 37 mm. The inner diameter (feret maximum) varied from 0.33 to 7.06 mm at midpoint. The breadth of the multiple sinuses did not exceed the mean of our series except in one case. The occipital sinus, which is generally ellipsoid in shape, functions in the majority of cases as a thin, single midline sinus. It may have less resistant recesses laterally.

1 Bookmark
 · 
53 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A study has been made of the scintillation, luminescent and kinetic characteristics of full size (25 radiation lengths) PbWO<sub>4 </sub> single crystals, obtained in the optimal condition. It is shown that the light yield of the crystals is 11-14 phe/MeV, the constants of decay time are less than 100 ns, depending upon crystallization features, medium of growth, the oxygen content and thermal annealing
    IEEE Transactions on Nuclear Science 07/1997; · 1.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The standard approach of midline suboccipital craniectomy entails sacrifice of the Occipito-marginal sinus. We have attempted to preserve this venous channel by using a durotomy technique which preserves this system. In a pilot study initiative, two groups of patients using this technique versus the standard approach, were compared in terms of per and post operative benefits, morbidity and complications. The literature with reference to the anatomy and venous flow dynamics of the occipital and marginal sinuses and their significance has been reviewed. Similarly, literature regarding dural closure technique with reference to postoperative complications has also been reviewed. In this novel approach, the dura is opened as a crescent to avoid damage to the occipital sinus. This technique was compared with the standard midline dural opening technique by random usage of both techniques in 24 patients. The 'crescent' approach has been found to reduce the need for duroplasty, with comfortable primary closure and to reduce the risk of postoperative pseudomeningocele. This is a novel dural opening technique which attempts to preserve the normal venous flow physiology. In essence it helps in increased primary dural closures and reduction of Pseudomeningiocele/CSF leak as well as blood loss and venous hypertension.
    Acta Neurochirurgica 08/2012; 154(11):2115-21. · 1.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a global, closed-loop, multiscale mathematical model for the human circulation including the arterial system, the venous system, the heart, the pulmonary circulation and the microcirculation. A distinctive feature of our model is the detailed description of the venous system, particularly for intracranial and extracranial veins. Medium to large vessels are described by one-dimensional hyperbolic systems while the rest of the components are described by zero-dimensional models represented by differential-algebraic equations. Robust, high-order accurate numerical methodology is implemented for solving the hyperbolic equations, which are adopted from a recent reformulation that includes variable material properties. Because of the large intersubject variability of the venous system, we perform a patient-specific characterization of major veins of the head and neck using MRI data. Computational results are carefully validated using published data for the arterial system and most regions of the venous system. For head and neck veins, validation is carried out through a detailed comparison of simulation results against patient-specific phase-contrast MRI flow quantification data. A merit of our model is its global, closed-loop character; the imposition of highly artificial boundary conditions is avoided. Applications in mind include a vast range of medical conditions. Of particular interest is the study of some neurodegenerative diseases, whose venous haemodynamic connection has recently been identified by medical researchers. Copyright © 2014 John Wiley & Sons, Ltd.
    International journal for numerical methods in biomedical engineering. 01/2014;