miércoles, 18 de mayo de 2016

Arteria de Adamkiewicz / Artery of Adamkiewicz

Mayo 18, 2016. No. 2330


 



Visualización preoperatoria de la arteria de Adamkiewicz con angiografía TC de doble fase en pacientes con aneurisma aórtico
Preoperative visualization of the artery of Adamkiewicz by dual-phase CT angiography in patients with aortic aneurysm.
Kurume Med J. 2011;58(4):117-25.
Abstract
To improve our ability to visualize the Adamkiewicz artery (AKA), we developed a modified intravenous CT angiography technique, which we refer to as right atrial CT (RA-CT) angiography. In this study, AKA detection rate and visualization of the arterial continuity from the aorta to the anterior spinal cord artery (ASA) was evaluated using RA-CT angiography.We performed RA-CT angiography in 110 patients with abdominal, thoracic descending, or thoracoabdominal aortic aneurysms. In RA-CT angiography, contrast medium with a high iodine concentration (370 mg/dl) was injected twice into the right atrium at a high injection rate (8.0 ml/sec), and two CT scans, starting at 20 sec after the first injection and at 35 sec after the second injection, respectively, were performed. All CT images were obtained using an 8- or 16-detector CT scanner at a slice thickness of 0.625 mm. The AKA was defined as the largest radiculomedullary artery with a characteristic hairpin turn, and with continuity from the aorta to the ASA.The AKA with hairpin turn was detected in all patients (100%), and continuity from the aorta to the ASA was confirmed in 99 of the 110 patients (90.0%). The AKA arose between Th8 and L1 in 86 of these patients (86.8%), and originated from the left side in 71 patients (71.7%).RA-CT angiography may be useful for visualizing the AKA and the arterial continuity from the aorta to the ASA in patients with aortic aneurysm, although the use of more advanced CT machines will provide safe and easy identification of the AKA and arterial continuity with a small amount of contrast medium and a single scan.
Localización intraforaminal de la gran arteria radiculomedular anterior (Arteria de Adamkiewicz) Revisión retrospectiva
Intraforaminal location of the great anterior radiculomedullary artery (artery of Adamkiewicz): a retrospective review.
Pain Med. 2010 Dec;11(12):1756-64. doi: 10.1111/j.1526-4637.2010.00948.x. Epub 2010 Sep 7.
Abstract
PURPOSE: The purpose of this study was to better characterize the intraforaminal location of the great anterior radiculomedullary artery (artery ofAdamkiewicz [AKA]) within the neural foramen that would allow safer targeting of thoracic and lumbar transforaminal epidural steroid injections. MATERIAL AND METHODS: A retrospective review of conventional thoracic and lumbar spinal angiograms performed at the Mayo Clinic from 1998-2008 was conducted. Two hundred forty-eight patients were identified and their spinal angiograms reviewed. The cephalo-caudal location of the AKA within the foramen at the mid-pedicular plane was documented along with the side and level of the AKA. RESULTS: From the 248 patients, 113 radiculomedullary arteries could be clearly evaluated within a neural foramen. The AKA was located in the superior one-half of the foramen in 97% (110). Eighty-eight percent (100) were located in the upper third; 9% (10) were located in the middle third; and 2% (2) were located in the lower third. The AKA was never seen in the inferior one-fifth of the foramen. Eighty-eight percent (100) of the radiculomedullary arteries were located on the left while 17% (20) were located on the right. The radiculomedullary arteries were identified from T2-L3. 92% (110) were located between T8 and L1. 28% (34) were located at T10, the highest incidence. CONCLUSIONS: The AKA was overwhelmingly located in the superior aspect of the neural foramen. Contrary to traditional teaching, the safest needle placement for an epidural steroid injection, particularly at L3 and above, may not be in the superior aspect of the foramen, but rather in an inferior and slightly posterior position within the foramen and relative to the nerve.
Reconstrucciones en 3D de las arterias medulares usando angiografía TC. Aplicaciones en procedimientos de invasión mínima
3D reconstructions of spinal segmental arteries using CT angiography: applications in minimally invasive spinal procedures.
AJNR Am J Neuroradiol. 2010 Oct;31(9):1635-9. doi: 10.3174/ajnr.A2137. Epub 2010 May 27.
Abstract
BACKGROUND AND PURPOSE: Injury to spinal segmental arteries may potentially occur during spinal surgery, particularly during anterior or minimally invasive approaches. Use of a noninvasive radiologic tool to evaluate these arteries before surgery may reduce this risk. MATERIAL AND METHODS: We performed spinal CT angiography and reconstructed 3D images of segmental arteries in 41 patients. We classified the pathways and locations of the segmental arteries into 4 zones (A, B, C, and D) according to pedicle and vertebral endplates. We designated segmental arteries from T8 to L1 as "high-level segmental arteries" and those from L2 to L4, as "low-level segmental arteries." We compared the distribution of segmental arteries between these 2 groups. We also investigated anatomic variations of segmental arteries and the rate of occurrence of the artery of Adamkiewicz. RESULTS: In all patients, 3D reconstruction images from spinal CT angiography clearly showed the pathways of segmental arteries on the vertebral bodies. Most of the segmental arteries passed the middle portion of the vertebral body (zones B and C). However, 51 of 738 segmentalarteries (6.9%) had uncommon pathways (zones A and D), and segmental arteries from L2 to L4 had a higher incidence of uncommon pathways than higher level vertebrae (P < .05). We also observed 2 types of segmental artery anatomic variation, agenesis and dual supply. CONCLUSIONS:
We suggest that spinal CT angiography can help to precisely visualize the spinal segmental arteries and surrounding bony structures and can aid clinicians in deciding on optimal approaches for spinal surgery.
VIII Foro Internacional de Medicina del Dolor y Paliativa 
Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán
Junio 9-11, Ciudad de México
Dra. Argelia Lara Solares
Tel. 5513 3782  www.dolorypaliativos.org 
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Anestesiología y Medicina del Dolor

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Copyright © 2015

Inician Jornadas Académicas en el marco del 51 Aniversario del “Aurelio Valdivieso”

Inician Jornadas Académicas en el marco del 51 Aniversario del “Aurelio Valdivieso”

lunes, 16 de mayo de 2016

Arterias medulares / Spinal arteries

Mayo 16, 2016. No. 2328


 



Avances  en angiografía-resonancia magnética de la médula espinal
Advances in spinal cord MR angiography.
AJNR Am J Neuroradiol. 2008 Apr;29(4):619-31. doi: 10.3174/ajnr.A0910. Epub 2008 Jan 17.
Abstract
Novel developments in MR angiography are reviewed that enable non-invasive clinical imaging of normal and abnormal vessels of the spinal cord. Current fast contrast-enhanced MR techniques are able 1) to visualize vessels supplying or draining the spinal cord and 2) to differentiate spinal cord arteries from veins. The localization of the Adamkiewicz artery, the largest artery supplying the thoracolumbar spinal cord, has become possible in a reproducible and reliable manner. Knowledge of the anatomic location of this artery and its arterial supplier may be of benefit in the work-up for aortic aneurysm surgery to reduce incidences of ischemic injury. Spinal cord MR angiography is ready to become a diagnostic tool that can compete with catheter angiography for detecting and localizing arterial feeders of vascular lesions and is strongly advised for use prior to invasive catheter angiography. Successful clinical application strongly relies on in depth knowledge of the complex spinal cord vasculature and skills in image postprocessing.
PDF 
 El embolismo emergiendo como una de las principales causas de lesión de la médula espinal después de la reparación aórtica descendente y toracoabdominal con un enfoque contemporáneo: hallazgos en resonancia magnética de lesiones de la médula espinal.
Embolism is emerging as a major cause of spinal cord injury after descending and thoracoabdominal aortic repair with a contemporary approach: magnetic resonance findings of spinal cord injury.
Interact Cardiovasc Thorac Surg. 2014 Aug;19(2):205-10. doi: 10.1093/icvts/ivu148. Epub 2014 May 14.
Abstract
OBJECTIVES: We reviewed magnetic resonance (MR) findings of the spinal cord in patients who had a spinal cord injury after descending and thoracoabdominal aortic repair, to speculate the specific cause of the injury. METHODS: Between 2000 and 2012, 746 patients underwent descending or thoracoabdominal aortic surgery: 480 received an open repair with adjuncts of spinal cord protection [distal perfusion, cerebrospinal fluid (CSF) drainage, reattachment of intercostal arteries and hypothermia] and 266 received an endovascular repair. Twenty-six (3.5%) suffered a spinal cord injury. Of these, 18 (14 open repair and 4 endovascular repair) underwent postoperative spinal cord MRI. Preoperative identification of the Adamkiewicz artery (ARM) was obtained in all patients except 1. Aortic pathology was dissection in 2 and non-dissection in 16 patients. RESULTS: There were 3 types MRI finding: sporadic infarction involving a range of spinal cord (sporadic); focal and asymmetrical infarction within a few segments of vertebra (focal); and diffuse and symmetrical infarction around the level of the ARM (diffuse). In endovascular repair, sporadic infarction was observed in all patients (4 of 4). In open repair, sporadic infarction was observed in 3 (21%), focal infarction in 7 (50%) and diffuse infarction in 4 (29%). In all patients who had sporadic or focal infarction, the aortic pathology was non-dissection. CONCLUSIONS: From these findings, embolism is 1 of the major causes of spinal cord injury in the era of adjuncts to optimize spinal cord haemodynamics during aortic repair.
 Ubicación intraforaminal de las arterias medulares anteriores toracolumbares.
Intraforaminal location of thoracolumbar anterior medullary arteries.
Pain Med. 2013 Jun;14(6):808-12. doi: 10.1111/pme.12056. Epub 2013 Feb 25.
Abstract
BACKGROUND: Transforaminal epidural steroid injection (TFESI) is a widely utilized interventional pain technique for radicular pain. Although the six o'clock position of the pedicle in the so-called "safe triangle" has been used as a target location, there have been a number of reported catastrophic complications of this procedure, including paraplegia. The mechanism of this has been attributed to the intravascular injection of steroids. The goal of this study was to examine the intraforaminal location of thoracolumbar medullary arteries which would help guide pain physicians in developing safer techniques and guidelines. METHODS: Twenty-four (24) embalmed cadavers were dissected and examined for the presence and distribution of thoracolumbar anterior medullary arteries. Access to the anterior surface of the spinal cord was made via anterior corpectomy from C2 to S5. Each medullary artery's course was determined by dissection from its origin, the anterior spinal artery, through the intervertebral foramen. The foramen was subsequently opened in the coronal plane, and the intraforaminal location of the artery, its diameter, and its relation to other foraminal structures were examined and measured. RESULTS: In the thoracolumbar foramina (T4-L2), 39 anterior medullary arteries were found, including 23 great medullary arteries (Adamkiewicz artery). One Adamkiewicz artery was found to be located in the left S2 foramen and was not included in the statistical analysis. Of the analyzed 39 anterior medullary arteries, 29 (74%) were located in the upper 1/3 of the foramen, 9 (23%) were located in the middle, and 1 (3%) artery was located in the lower 1/3. In relation to the dorsal root ganglion--ventral root complex, 21 (54%) arteries were located anterosuperiorly, 16 (41%) anteriorly, and 2 (5%) anteroinferiorly. The average intraforaminal artery diameter was 1.20 mm (0.84-1.91 mm). At thoracolumbar levels, theartery is almost always (92% ± 15%) located anterosuperior to the nerve. At typical thoracic levels, it is less often anterosuperior (38% ± 19%), but more often anterior to the nerve. CONCLUSIONS: At thoracolumbar levels, if needles were to encounter an artery, they are most likely to do so if placed anterosuperior to the nerve. Encountering an artery anterosuperior to the nerve is less likely at typical thoracic levels, but the likelihood is far from negligible. Pain physicians should be cognizant of this when considering optimal needle placement during transforaminal epidural steroid injections.
VIII Foro Internacional de Medicina del Dolor y Paliativa 
Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán
Junio 9-11, Ciudad de México
Dra. Argelia Lara Solares
Tel. 5513 3782  www.dolorypaliativos.org 
Like us on Facebook   Follow us on Twitter   Find us on Google+   View our videos on YouTube 
Anestesiología y Medicina del Dolor

52 664 6848905

Copyright © 2015