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PubMed1975

[Transoral approach for the treatment of atlanto-axial dislocation with the Os odontoideum and obstruction of the bilateral vertebral arteries (author's transl)].

The two approaches are well-known in the surgical treatment of atlanto-axial dislocation, the one is the anterior and the other is the posterior approach. The indication of these methods is still controversial. This report concerns with one case of atlanto-axial dislocation with the separate odontoid and bilateral obstruction of both vertebral arteries, which was successfully treated by transoral decompression and fusion between the bodies of the atlas and axis. The reasons why we chose this method were: (1) the spinal cord decompression was necessary because of the presence of compression of the cord by the separate odontoid process, (2) the spinal fusion had to be performed to stabilize the atlanto-axial articulation, (3) it was necessary to avoid the damage of collateral circulations to the brainstem through the deep cervical arteries demonstrated by bilat vertebral angiography. The posterior approach is highly susceptible to injure these collateral circulations.

Adolescent↗
PubMed1987

Dorsal cerebral collaterals of stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar Kyoto rats (WKY).

Earlier studies established that stroke-prone spontaneously hypertensive rats (SHRSP) invariably infarct after middle cerebral artery (MCA) occlusion. Normotensive rats are usually protected from infarction after the occlusion. Objectives of this study were to characterize the anastomosing collaterals that may determine the different outcomes to MCA occlusion in SHRSP and Wistar Kyoto rats (WKY). Young (5-10 week) and old (40-69 week) rats of each sex were anesthetized, then administered papaverine to produce maximal vasodilatation of the cerebrovascular bed. Under control conditions latex was injected into the arterial tree to measure the internal diameter of branches of the anterior cerebral artery (ACA), the MCA, and the ACA-MCA anastomosing collaterals. Large diameter ACA and MCA rami in old, but not young, SHRSP were significantly smaller in diameter than the respective ACA and MCA branches in old WKY. The number of ACA-MCA anastomoses was the same for SHRSP and WKY. Mean internal diameter of the ACA-MCA anastomoses was significantly (p less than 0.0001) smaller in SHRSP than WKY in both age groups. There were significant negative correlations between age and 1) the internal diameter of the ACA-MCA anastomoses in WKY but not SHRSP, and 2) the largest diameter ACA and MCA rami in SHRSP but not WKY. The findings suggest that vascular resistance of fully relaxed collaterals is greater in SHRSP than WKY, thereby compromising the dorsal collateral circulation before large diameter vessel changes occur that accompany the established form of hypertension.

Age Factors↗
PubMed1988

Preservation of left ventricular function in patients with total occlusion of the left anterior descending coronary artery and wide-caliber distal vessel filling by collateral vasculature.

The segmental ventricular function of 76 patients with total occlusion of the left anterior descending coronary artery (LAD) was analyzed to establish the relationship between ventricular function and the presence and angiographic appearance of the collateral circulation. The relationship between function and collateral supply was found to be significant (P less than .01). The only angiographic feature of the collateral vasculature that was associated with preserved function was the caliber of the distal LAD. Wide-caliber vessels were more likely to be associated with preserved ventricular function than thin vessels (P less than .01). In contrast, both rapidly filling collateral arteries and slow filling vessels were associated with preserved ventricular function. Collateral supply maintenance was significantly associated with preserved ventricular function, even when the collaterals arose from stenotic coronary arteries. Furthermore, despite marked differences in ventricular function between the base and apex of the heart, there was a true relationship between preserved ventricular function and the presence of collateral vessels for all segments of the anterior wall. These findings may be relevant to clinical decision making and to proper interpretation of studies of ventricular function following LAD occlusion.

Angiography↗
PubMed1996

A source of haemorrhage in adult patients with moyamoya disease: the significance of tributaries from the choroidal artery.

This study concerns 19 patients over 16 years of age with Moyamoya disease. Ten cases of intracranial haemorrhage, as the initial haemorrhagic event in patients aged from 21 to 55 (haemorrhagic group) and 9 cases of ischaemic events in 18- to 53-year-old patients (ischaemic group) were included. All haemorrhages were associated with intraventricular haemorrhages (IVH); and all but one case of thalamic haemorrhage were thought to be primary IVH (2 cases of small paraventricular haemorrhage; 2 of small haemorrhages in the splenium; 5 with no intracerebral haematoma). In the 9 patients of the ischaemic group, there were 2 cases of transient ischaemic attacks and 7 of cerebral infarction. Angiographic evaluations demonstrated that the abnormal basal vessel formation and the collateral supplies from the external carotid arteries were poorly developed in both groups. In contrast, the collateral circulation via the choroidal and posterior pericallosal arteries was well demonstrated. Furthermore, marked enlargement of the choroidal arteries and the medullary arteries derived from them was seen more frequently in the haemorrhagic group. These findings suggested that the haemodynamic load in the vessels supplying the walls of the posterior parts of the ventricles and the periventricular region was increased, especially in the haemorrhagic group. Those vessels were considered to be important sites of IVH in adult patients with Moyamoya disease.

Adult↗
PubMed1994

Long-term changes in cerebral blood flow according to different types of ischemic stroke.

Recurrence of ischemic stroke may be related to chronic hemodynamic failure of the brain. Long-term changes in cerebral blood flow (CBF) remain undetermined for each ischemic stroke subtype. We performed the present study to clarify this issue. The study group consisted of 77 unilateral, hemispheric, ischemic stroke patients who had a single stroke episode; atherothrombotic stroke in 34, cardioembolic in 26 and lacunar in 17. We measured baseline CBF in the affected and unaffected hemispheres 1.0-3.4 months after stroke onset, then repeated the measurements 10 months to 10 years later (mean 43.7 months), with the xenon-133 inhalation method. We analyzed changes in CBF in relation to other clinical characteristics. CBF in the affected hemisphere changed differently among the stroke subtypes (P < 0.01); increased in the atherothrombotic group, particularly within 40 months of stroke; remained unchanged in the cardioembolic group; and decreased in the lacunar group, especially later than 40 months of stroke. In the atherothrombotic group, CBF increased in hypertensive patients but decreased in normotensives (7.9 +/- 2.4% and -3.6 +/- 3.9%, respectively; P < 0.05). Present results suggest that long-term changes in CBF depend on ischemic stroke subtype. Development of collateral circulation may occur after several years in atherothrombotic stroke patients. The findings raise doubts about the significance of chronic hemodynamic failure as a cause of stroke recurrence.

Adult↗
PubMed2004

Elevated fluid shear stress enhances postocclusive collateral artery growth and gene expression in the pig hind limb.

OBJECTIVE: The role of fluid shear stress (FSS) in collateral vessel growth remains disputed and prospective in vivo experiments to test its morphogenic power are rare. Therefore, we studied the influence of FSS on arteriogenesis in a new model with extremely high levels of collateral flow and FSS in pig and rabbit hind limbs. METHODS AND RESULTS: A side-to-side anastomosis was created between the distal stump of one of the bilaterally occluded femoral arteries with the accompanying vein. This clamps the collateral reentry pressure at venous levels and increases collateral flow, which is directed to a large part into the venous system. This decreases circumferential wall stress and markedly increases FSS. One week after anastomosis, angiographic number and size of collaterals were significantly increased. Maximal collateral flow exceeded by 2.3-fold that obtained in the ligature-only hind limb. Capillary density increased in lower leg muscles. Immunohistochemistry revealed augmented proliferative activity of endothelial and smooth muscle cells. Intercellular adhesion molecule-1 and vascular cell adhesion molecule (VCAM)-1 were upregulated, and monocyte invasion was markedly increased. In 2-dimensional gels, actin-regulating cofilin1 and cofilin2, destrin, and transgelin2 showed the highest degree of differential regulation. CONCLUSIONS: High levels of FSS cause a strong arteriogenic response, reinstate cellular proliferation, stimulate cytoskeletal rearrangement, and normalize maximal conductance. FSS is the initiating molding force in arteriogenesis. The role of fluid shear stress on the development of a collateral circulation was studied by abruptly increasing collateral blood flow by a distal femoral artery-to-vein anastomosis. This increased number and size of collateral vessels to a hitherto unknown degree. Fluid shear stress is the primary and strongest arteriogenic stimulus.

Actin Depolymerizing Factors↗
PubMedDate not supplied

Influence of anesthetics on metabolic, functional and pathological responses to regional cerebral ischemia.

Regional cerebral ischemia was produced by common carotid artery occlusion in gerbils and by middle cerebral artery occlusion in dogs, cats, and squirrel monkeys. Anesthesia was induced with either pentobarbital or halothane and maintained for two to three hours after vessel occlusion. In acute studies, the effect of regional cerebral ischemia on cerebral concentrations of ATP, phosphocreatine, lactate, and pyruvate was determined at the end of this period in gerbils, cats, and squirrel monkeys. In chronic studies, the degree of neurological deficit and size of cerebral infarction were determined 48 hours after a two-hour to three-hour period of vessel occlusion in cats and squirrel monkeys and permanent occlusion in dogs. In gerbils, dogs, and cats, there were no differences in the metabolis, functional, or pathological effects of anesthesia with pentobarbital or halothane. However, in the squirrel monkey, in acute studies the metabolic alterations were significantly less with pentobarbital, and in chronic studies the frequency and magnitude of functional deficits and cerebral infarction were significantly less. We conclude that pentobarbital does provide a degree of protection during regional cerebral ischemia but that such effects are only consistently demonstrable in primates. In nonprimates, we assume that variability in the collateral circulation renders demonstration of significant differences difficult or impossible.

Adenosine Triphosphate↗
PubMed1979

Regional cerebral blood flow and oxygen utilization in superficial temporal-middle cerebral artery anastomosis patients: an exploratory definition of clinical problems.

Regional cerebral blood flow (rCBF) and regional cerebral oxygen utilization (rCMRO2) were measured before and after surgery in nine patients undergoing a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis to bypass cerebrovascular lesions not amenable to extracranial operative procedures. The objective of these studies was to determine whether measurements of this type could provide objective criteria for surgery as well as assess the effect of surgery. The preliminary data, although limited, suggest that measurements of regional cerebral hemodynamics and metabolism in these patients before and after surgery provide valuable data upon which to develop criteria and assess results. For example, 1) a significant depression of rCBF and rCMRO2 in patients in whom a major cerebral infarction has not occurred, or 2) relative preservation of rCMRO2 despite depressed rCBF seem to be favorable indications for establishing a functioning STA-MCA anastomosis. In such patients, STA-MCA anastomosis can be followed by a return of rCBJ and rCMRO2 to virtually normal levels. Relatively normal rCBF and rCMRO2 in the presence of an occluded internal carotid artery in asymptomatic patients indicates satisfactory collateral circulation and is probably a contraindication to surgery.

Adult↗
PubMed2001

[Usefulness of time-resolved projection MRA on evaluation of hemodynamics in cerebral occlusive diseases].

The usefulness for evaluation of cerebral hemodynamics using time-resolved projection MRA was studied in normal volunteers and patients of cerebrovascular diseases. Six normal volunteers and ten patients with cerebrovascular occlusive diseases including 6 of IC occlusion and 4 of post EC/IC bypass surgery underwent time-resolved projection MRA on a 1.5 T clinical MRI system. Projection angiograms are acquired with 2 D-fast SPGR sequence with a time resolution of approximately one image per second, 40 images being acquired consecutively before and after bolus injection Gd-DTPA. And all images were calculated by complex subtraction from the background mask in a work station. In normal volunteers, the quality of images of time-resolved projection MRA was satisfactory. The arteries from internal carotid artery through M 2 segment of middle cerebral artery and all major venous systems were well portrayed. In 4 cases of IC occlusion who were assessed the collateral flow through the anterior communicating artery and posterior communicating artery, there were delayed to demonstrate the ipsilateral MCA. However, in 2 cases of IC occlusion that were assessed the collateral flow through leptomeningeal anastomosis, ipsilateral MCA and collateral circulation were not demonstrated. In all patients of post EC/IC bypass surgery, the patency of EC/IC bypass could be evaluated as properly with time-resolved projection MRA as 3 D-TOF MRA. Although the temporal and spatial resolutions are insufficient, time-resolved projection MRA was powerful non-invasive method to evaluate the cerebral hemodynamics via the basal communicating arteries in IC occlusion and identify the patency of EC/IC bypass.

Adult↗
PubMed1990

[Significance of inferior ST segment changes in acute anterior myocardial infarction--relationship between the distribution of left anterior descending artery and concomitant ischemia of the inferior wall].

The significance of inferior ST segment changes was studied in 23 patients with acute anterior myocardial infarction by the distribution of the left anterior descending artery (LAD) after percutaneous transluminal coronary recanalization. In 9 patients (Group A) LAD supplied the anterior wall of the left ventricle up to or including the apex but did not reach the inferior wall; in 8 patients (Group B) it continued beyond the apex onto the inferior wall of the left ventricle with well developed collateral circulation; in 6 patients (Group C) it continued beyond the apex onto the inferior wall of the left ventricle with less-developed or no collateral circulation. Thallium-201 scintigraphy and contrast left ventriculography showed that inferior myocardial ischemia was significantly more prominent in Group C than Group A. These results were consistent with coronary anatomy. Inferior ST segment was significantly more depressed in Group A with no concomitant inferior wall ischemia, than in Group C with concomitant inferior wall ischemia (maximal inferior ST segment change: -1.7 +/- 1.1; 0.8 +/- 1.7 mm, respectively; p less than 0.02). In Group A inferior ST segment was depressed in all 6 patients with lateral ST segment elevation, but it was depressed in only one of 3 patients with no lateral ST segment change. Lateral ST segment elevation tended to cause inferior ST segment depression. This study indicates that the inferior ST segment changes in patients with acute anterior myocardial infarction depend on concomitant ischemia of the inferior wall of the left ventricle by the distribution of LAD and the lateral ST segment changes.

Adult↗
PubMed2002

Coarctation of the aorta: comparison of aortic dimensions between conventional MR imaging, 3D MR angiography, and conventional angiography.

Magnetic resonance angiography is increasingly used as a non-invasive method in the evaluation of coarctation of the aorta. The aim of this study was to compare aortic dimensions calculated by MR angiography and those obtained by more conventional MR sequences and conventional angiography. Twenty-six consecutive patients with coarctation underwent three-dimensional MR angiography. Two independent observers retrospectively evaluated three aortic segments, site of coarctation, presence of aneurysm and existence of collateral circulation. Three aortic segments were also compared with those obtained on classical MR sequences and conventional angiography. The MR angiography was successfully performed in all showing 1 aneurysm and collateral circulation in 8 patients. Almost perfect intraobserver ( r(2)>0.91) and excellent interobserver ( r(2)>0.80) reliabilities were obtained for each aortic segment no matter which MR sequence was employed. Similarly, mainly excellent ( r(2)>0.80) concordance analysis was observed between MR angiography measurements and those calculated by either spin-echo/gradient-echo sequences or conventional angiography. This study demonstrates that MR angiography is a fast, accurate and reproducible method in the evaluation of coarctation of the aorta. It provides excellent anatomic information and reliably detects collateral vessels. Magnetic resonance angiography could probably replace the conventional angiography and will provide an additional diagnostic value in combination with turbo spin-echo sequence.

Adolescent↗
PubMed2000

Local intraarterial fibrinolytic therapy for embolic stroke associated with vascular anomalies--two case reports.

Two cases of embolic stroke associated with vascular anomalies were treated by intraarterial fibrinolytic therapy. A 78-year-old male had embolic stroke associated with fenestration of the middle cerebral artery (MCA). The embolus lodged in the terminal portion of the right internal carotid artery (ICA) and in the M2 portion of the right MCA. The fenestration was not detected before local fibrinolytic therapy, but was identified by postinterventional angiography. An 82-year-old female had a left-sided persistent primitive trigeminal artery (PPTA), and the embolus lodged in the terminal portion of the left ICA. Left internal carotid angiography also showed rich collateral circulation via the abundant leptomeningeal anastomosis. The PPTA involved the left ICA, so the anomalous anatomy had to be considered in performing local thrombolysis. However, the rich collateral circulation allowed recanalization of the occluded ICA without inducing bleeding. Dissolution of persistently adherent emboli must be performed with great care because of the possibility of such rare vascular anomalies.

Aged↗
PubMedDate not supplied

[Atypical presentation of right coronary artery occlusion].

INTRODUCTION: Inferior wall myocardial infarctions are usually benign and uncomplicated and rarely result in ventricular disturbances of the heart rhythm. An unusual presentation of an inferior acute myocardial infarction (AMI) with atypical symptoms, and ventricular tachycardia is described. CASE REPORT: A 44-year-old patient was admitted to the coronary care unit (CCU) due to atypical chest pain during exercise and ECG abnormalities in leads L2, L3 and aVF. On admission, ECG could mimic myocarditis, pericardial effusion, left anterior bundle branch block or early repolarization. Two-dimensional echocardiography revealed a hypertrophic myocardium without abnormal regional wall motion, good left ventricular function and ejection fraction of 65%. The presumptive prediction of a culprit artery based on the ECG recorded on admission was conclusive for inferior AMI. Fibrinolytic therapy was started 3 hours after the onset of chest pain. Resolution of ST segment elevation and relief of chest pain occurred within one hour of the infusion. On the fifth day after admission, the patient had a nonsustained ventricular tachycardia (VT) which was resolved with amiodarone. Angiography showed acute occlusion of the mid portion, right coronary artery (RCA) and collateral circulation in the distal portion. DISCUSSION AND CONCLUSION: Malignant ventricular arrhythmias can result from isolated inferior wall AMI, but literature reports on this phenomenon are rather rare. Collateral circulation can prevent myocardial ischemia and preserve myocardial function, but does not provide protection against exercise-induced myocardial ischemia.

Adult↗
PubMed1981

[Superior vena cava syndrome: a rare complication of endocavitary cardiac pacing].

The superior vena cava syndrome is an exceptionally rare complication of endocavitary cardiac pacing, asymptomatic venous thrombosis being much more common. Two cases wee observed as late complications of pacemaker implantation. In the first case the clinical signs regressed with the development of a collateral circulation under heparin therapy after failure of fibrinolytic drugs. In the second one, the severity of the superior vena cava syndrome and the poor quality of the collateral circulation led to the implantation of a Gore-Tex prosthesis. This surgical bypass led to a rapid and complete regression of the clinical signs. It would seem to be a valuable alternative when anticoagulant therapy fails.

Cardiac Pacing, Artificial↗
PubMed2000

Triphasic perfusion computed tomography in acute middle cerebral artery stroke: a correlation with angiographic findings.

OBJECTIVE: To evaluate the usefulness of triphasic perfusion computed tomography (TPCT) in diagnosing middle cerebral artery (MCA) occlusion and in assessing the perfusion deficit and collateral circulation in patients with acute ischemic stroke. BACKGROUND: Conventional angiography is the criterion standard for the diagnosis of MCA occlusion and for the assessment of perfusion deficit and collateral blood supply. The risk of hemorrhagic transformation after recanalization of occluded arteries by thrombolytic therapy is considered high when pretherapeutic residual flow is markedly reduced. PATIENTS AND METHODS: In 8 patients within 3 hours of onset of acute MCA stroke, precontrast computed tomographic scans were taken, and then TPCT was performed after power-injector controlled intravenous administration of contrast media. Sequential images of early, middle, and late phases were obtained. The whole procedure took 5 minutes. Perfusion deficit on TPCT was graded as "severe" or "moderate," depending on the state of collateral flow. Digital subtraction angiography (DSA) was performed in all patients within 6 hours of acute stroke. Direct intra-arterial urokinase infusion was begun immediately after the angiographic superselection of the MCA occlusion site in 6 of the 8 patients within 7 hours of onset (range, 4.3-6.2 hours). RESULTS: The DSA findings showed occlusion of the MCA stem (n = 1) and at the bifurcation (n = 4). The sites of proximal MCA occlusion could be identified on the early and middle images of TPCT in all 5 patients. On DSA findings, all 8 patients had a zone of perfusion deficit with markedly slow leptomeningeal collaterals and a zone of perfusion deficit with no collaterals. The zone of severe perfusion deficit on TPCT corresponded to the zone of perfusion deficit with no or few collaterals on angiography, and the zone of moderate perfusion deficit on TPCT corresponded to that of perfusion deficit with markedly slow leptomeningeal collaterals. Early parenchymal hypoattenuation on precontrast computed tomography was confined to the zone of severe perfusion deficit on TPCT. The initial National Institutes of Health Stroke Scale score correlated better with the total extent of severe perfusion deficit and moderate perfusion deficit on TPCT than that of severe perfusion deficit alone. After direct intra-arterial thrombolysis within 7 hours of onset, symptomatic hemorrhagic transformation did not develop in 4 patients with small severe perfusion deficit (33% or less of the presumed MCA territory). However, the remaining 2 patients with large severe perfusion deficit (more than 50% of the presumed MCA territory) deteriorated to death with hemorrhagic transformation. CONCLUSIONS: Triphasic perfusion computed tomography is useful for diagnosing proximal MCA occlusion and assessing perfusion deficit and collateral circulation as reliably as DSA. The zone of severe perfusion deficit on TPCT may be presumed to be the ischemic core, and that of moderate perfusion deficit, the penumbra zone. Triphasic perfusion computed tomography may be used as a rapid and noninvasive tool to make thrombolysis safer.

Acute Disease↗
PubMed2004

Isolated gastric varices due to focal splenic vein stenosis.

Left-sided portal hypertension due to splenic vein stenosis is a very rare disease. We report a case of this condition in a 21-year-old woman who suffered from a first episode of tarry stool passage with fresh blood vomiting. Panendoscopy showed isolated gastric varices while sonography showed a normal liver but the presence of splenomegaly with prominent collateral circulations. Further imaging studies, including abdominal computed tomography, splenoportography and percutaneous transhepatic portography, revealed a focal stenotic proximal splenic vein resulting in left-sided portal hypertension. The collateral circulation ran from the short gastric veins via the left gastric veins into the main portal vein. The intraportal venous pressure was within normal limits. Splenectomy was performed and near normal wedge liver biopsy pathology confirmed non-cirrhotic extrahepatic portal hypertension. The patient had no further variceal bleeding after surgery.

Adult↗
PubMed2006

Three-dimensional observation of blood vessels supplying the gland proper and capsule of the mouse submandibular gland.

Previous studies have shown that submandibular glands suffering interruption of the blood circulation from the main supplying artery have more surviving parenchymal cells in their peripheral portion than in their central portion. Although the reason for this difference between the peripheral and central portions has not yet been clarified, the existence of collateral circulation has been suspected. The present study was designed to examine whether or not the vessels binding the gland proper to the capsule provide such collateral circulation. Silicone rubber or methacrylate was injected into the main artery supplying the mouse submandibular gland, in which the gland proper is wrapped by a capsule similar to that of the human submandibular gland, and then the gland was observed by both stereoscopic and scanning electron microscopy. Three-dimensional observations showed no communicating vessels between the gland proper and the capsule. Therefore, it is suggested that the parenchymal cells surviving in the ischemic peripheral portion of the submandibular gland are nourished by permeation of tissue fluid contained in the capsule.

Animals↗