Feeding Artery (feeding + artery)

Distribution by Scientific Domains


Selected Abstracts


Improved target volume characterization in stereotactic treatment planning of brain lesions by using high-resolution BOLD MR-venography

NMR IN BIOMEDICINE, Issue 7-8 2001
Lothar R. Schad
Abstract In this methodological paper I report the stereotactic correlation of different magnetic resonance imaging (MRI) techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), functional MRI, and high-resolution BOLD venography (HRBV)] in patients with cerebral arterio-venous malformations (AVM) and brain tumors. The patient's head was fixed in a stereotactic localization system which is usable in both MR-systems and linear accelerator installations. Using phantom measurements global geometric MR image distortions can be ,corrected' (reducing displacements to the size of a pixel) by calculations based on modeling the distortion as a fourth-order two-dimensional polynomial. Further object-induced local distortions can be corrected by additionally measured field maps. Using this method multimodality matching could be performed automatically as long as all images are acquired in the same examination and the patient is sufficiently immobilized to allow precise definition of the target volume. Information about the hemodynamics of the AVM was provided by a dynamic MRA with the STAR technique, leading to an improved definition of the size of the nidus, the origin of the feeding arteries, whereas HRBV imaging yielded detailed and improved information about the venous pattern and drainage. In addition, functional MRI was performed in patients with lesions close to the primary motor cortex area, leading to an improved definition of structures at risk for the high-dose application in radiosurgery. In patients with brain tumors the potential of HRBV to probe tumor angiogenesis and its use in intensity-modulated treatment planning is still hampered by the open question of how to translate a BOLD signal pattern measured in the tumor to a dose distribution, which should be addressed in future studies. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Necrosis of the long process of the incus following stapes surgery: New anatomical observations,,

THE LARYNGOSCOPE, Issue 4 2009
Imre Gerlinger MD
Abstract Objectives/Hypothesis: The most frequent complication (generally recognized during revision procedures) following seemingly successful stapedotomies and stapedectomies is necrosis of the long process of the incus. This is currently ascribed to a malcrimped stapes prosthesis or to a compromised blood supply of the incus. The two-point fixation can cause a mucosal injury with a resulting toxic reaction, and also osteoclastic activity. An important aspect in the engineering of ideal stapes prostheses is that they should be fixed circularly to the long process of the incus with appropriate strength. The objective of this study was to compare current knowledge relating to the blood supply of the ossicular chain with the present authors' observations on cadaver incudes. Most of the papers dealing with this issue appeared in the mid-20th century. Methods: The published data were compared with the authors' findings gained from photodocumentation on 100 cadaver incudes. The photos were taken with a Canon EOS 20 digital camera (Canon, Inc., Lake Success, NY) with a 5:1 macro-objective. The long processes of the incudes were examined from four directions under a Leica surface-analyzing microscope (Leica Microsystems GmbH, Wetzlar, Germany). Results: Analysis of the positions of the entrances of the feeding arteries (nutritive foramina) on the incudes revealed 1-4 nutritive foramina on the long processes of 48% (24) of the left-sided incudes and 56% (28) of the right-sided incudes. The positions of these foramina differed, however, from those previously described in the literature. They were mostly located not on the medial side of the incus body or on the short process or on the cranial third of the long processes, but antero-medially, mostly on the middle or cranial third. In 48% of all the incudes examined, an obvious foramen was not observed either in the body or in the long process of the incus. No relationship was discerned between the chronological age of the incus specimens and the numbers and/or locations of the nutritive foramina. In each case, the opening of the foramen was the beginning of a tunnel running obliquely and medially upward through the corticalis of the long process of the incus. The foramina are thought to be capable of ensuring a richer blood supply between the surface and the inside of the long process, allowing the arteries to run in and out. Conclusions: These observations indicate that conclusions drawn from classical anatomical works appear to need reconsideration. The present authors consider that the reason for the necrosis of the long process of the incus is not a compromised blood supply, except in some exceptional anatomical situations. They discuss the possible reasons why malcrimping may lead to necrosis of the long process of the incus. To prevent such malcrimping, attention is paid to the new generation of prostheses. Laryngoscope, 2009 [source]


Successful management of uterine arteriovenous malformation by ligation of feeding artery after unsuccessful uterine artery embolization

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2009
Daisaku Yokomine
Abstract Uterine arteriovenous malformation (AVM) is a rare and potentially life-threatening disease. The present report describes a postmenopausal patient with uterine AVM manifesting recurrent, massive genital bleeding. Uterine artery embolization (UAE) was scheduled before hysterectomy, but UAE was unsuccessful due to the dilated, tortuous internal iliac arteries, and extremely rapid arterial blood flow. Hysterectomy appeared to carry a potential risk of massive blood loss due to multiple dilated vessels around the uterine corpus and cervix. Therefore, six arteries feeding the uterus were surgically ligated. At 10 months after the operation there have been no episodes of atypical genital bleeding. [source]


Experimental Study of a New Method for Early Detection of Vascular Access Stenoses: Pulse Pressure Analysis at Hemodialysis Needle

ARTIFICIAL ORGANS, Issue 2 2010
Koen Van Canneyt
Abstract Hemodialysis vascular access (VA) stenosis remains a frequent complication. However, early detection is challenging and costly. The aim of this in vitro study was to assess a new detection method based on pulse pressure analysis at the hemodialysis needle. A silicon model of a radiocephalic arteriovenous fistula was built in a mock loop. Pressure profiles were measured at the arterial hemodialysis needle and in the proximal feeding artery. Stenoses (50 and 25% diameter reduction) were created proximal to the anastomosis (proximal artery) and distal to the arterial needle (distal vein and proximal vein). The pulse pressure (PP) at the needle was divided by the PP at the feeding artery to obtain a dimensionless ratio, %PP. Experiments were conducted at different blood flow (500,1200 mL/min) and heart rates (60,90 beats/min) to test this new index over a wide range of hemodynamic conditions. In the control model (no stenosis), %PP was 20.26 ± 4.55. A proximal artery 50% stenosis significantly decreased %PP to 7.69 ± 2.08 (P < 0.0001), while the presence of 50% stenosis in the distal (36.20 ± 2.12) and proximal (32.38 ± 2.17) vein led to significantly higher values of %PP (P < 0.0001). For stenosis of 25% diameter reduction in the proximal artery, the %PP decreased to 15.45 ± 2.13 (P = 0.0022) and the %PP increased with a 25% stenosis in the distal vein to 26.71 ± 3.01 (P = 0.0003) and in the proximal vein to 26.53 ± 2.67 (P = 0.0004). This in vitro study shows that the analysis of the PP at the dialysis needle is useful for early detection and localization of hemodialysis VA stenosis, independent of heart rate and flow level. [source]