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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 44 year old man underwent successful surgery for a thoracoabdominal aortic aneurysm using a permanent bypass graft and aneurysmoplasty. This technique reduces visceral ischemia to a minimum and the aneurysmoplasty, through total preservation of the intercostal and lumbar arteries, can avoid paraplegia caused by spinal cord ischemia. Our technique is recommended as it can be performed easily, safely, and effectively without heparinization, temporary shunts or bypass perfusion.
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PMID:The surgical treatment of a thoracoabdominal aortic aneurysm with total preservation of the intercostal and lumbar arteries using a permanent bypass technique--a case report. 182 79

Between January 1, 1980, and June 30, 1989, 9 patients (6 males and 3 females) developed ischemic injury to the spinal cord or lumbosacral plexus following 3,320 operations on the abdominal aorta (0.3%). The incidence of this complication was 0.1% (2 of 1,901) after elective and 1.4% (3 of 210) after emergency abdominal aortic aneurysm repair, and 0.3% (4 of 1,209) after repair for occlusive disease. Three of the latter had prior clinical evidence of distal embolization. Eight grafts were bifurcated (aorto-iliac:four, aorto-femoral: three, aorto-ilio-femoral:one). One patient underwent extra-anatomic revascularization. Only two patients had supraceliac aortic cross-clamping and one patient underwent exclusion of both internal iliac arteries. Four patients had hypotension. Early mortality was 22% (two of nine). Severe perioperative complications, mostly due to associated visceral and somatic ischemia and sepsis, were present in seven of the nine patients. The extent and type of the neurologic injury correlated with long-term outcome. Patients with ischemic injury of the lumbosacral roots or plexus had better recovery. Attention to the pelvic circulation and the collateral blood supply is important. Use of gentle technique to prevent embolization, avoidance of hypotension and prolonged supraceliac cross-clamping, revascularization of at least one internal iliac artery, and the use of heparin may decrease but not eliminate paraplegia. Once this unexpected complication occurs, careful neurologic evaluation should be done to localize the lesion and aid prognosis.
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PMID:Ischemic injury to the spinal cord or lumbosacral plexus after aorto-iliac reconstruction. 186 33

Protein kinase C (PKC) is an important intracellular regulator, and its activity may play a central role in the modulation of neuronal ischemic damage. Staurosporine and the compound H-7 are potent in vitro inhibitors of PKC, and 1,2-oleoylacetylglycerol (OAG) is an effective activator. We administered these compounds through a spinal subarachnoid catheter and demonstrated in vivo alteration of spinal cord PKC activity. We then tested the effects of altering PKC activity in a well-established rabbit model of reversible spinal cord ischemia. Animals within each experimental group were subjected to a range of spinal cord ischemic durations by temporary occlusion of the infrarenal abdominal aorta. Compared to control, both staurosporine and H-7 significantly shortened the duration of ischemia that the animals could tolerate, without developing permanent paraplegia. OAG resulted in an insignificant lengthening of the ischemic duration that the animals could withstand. The worsening of ischemic outcome by PKC inhibitors suggests that the enzyme is important for maintaining neurologic function under ischemic conditions, possibly secondary to modulation of intracellular calcium levels.
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PMID:Effect of protein kinase C modulation on outcome of experimental CNS ischemia. 188 95

A case is described in which a coeliac plexus block with alcohol 48%, performed under X ray control, resulted in paraplegia. Ischaemia of the spinal cord, due to damage to the arterial blood supply, was thought to be the cause.
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PMID:Paraplegia following coeliac plexus block. 195 3

Permanent ligation of arteries supplying blood to the spinal cord in operations for aortic aneurysm can lead to spinal cord ischemia, which can result in either paraparesis or paraplegia. This report describes a rapid method of intraoperative identification of those arteries that supply the spinal cord by use of an intrathecal platinum electrode to detect hydrogen in solution that has been injected into the aortic ostia. Preservation or perfusion of those identified arteries supplying the spinal cord may decrease the rate of postoperative neurologic complications. Of 28 porcine experiments with postoperative observation for 24 hours, there were 3 initial pilot experiments in which saline saturated with hydrogen was injected into the temporarily cross-clamped aorta. Twenty animals were then randomized to (1) preservation of only the vessels sequentially identified to supply blood to the spinal cord from T-13 to L-5 (n = 10); (2) division of the vessels supplying the spinal cord (n = 10). A further five animals underwent perfusion experiments wherein the identified cord arteries were perfused by a shunt, the other nonsupply arteries were divided, and the aorta was kept clamped for 45 minutes. Spinal motor evoked potentials were elicited with an intrathecal electrode and were highly sensitive for paralysis. Paralysis occurred in 0/3 pilot (p less than 0.013 vs division); 8/10 division; 1/10 preservation (p less than 0.0017 vs division); and perfusion 1/5 (p less than 0.025 vs division). Results of a pilot study in eight humans shows that the technique can be used to rapidly identify segmental arteries supplying the spinal cord, to determine if distal perfusion is supplying the spinal cord with blood flow, and if reattached segmental arteries are patent.
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PMID:Influence of preservation or perfusion of intraoperatively identified spinal cord blood supply on spinal motor evoked potentials and paraplegia after aortic surgery. 199 54

Widening of the mediastinum, when seen on radiographs of the chest in victims of trauma, is usually attributed to injury to the aorta. An aortic injury, when not lethal, often causes paraparesis or paraplegia due to ischemia of the spinal cord. A fracture of the upper thoracic spine can produce similar clinical and radiographic findings. The cases of three patients who had those findings are presented; in all three, the differential diagnosis between the vascular and skeletal injuries was difficult. Fracture of the thoracic spine should be included in the differential diagnosis whenever mediastinal widening is seen on radiographs.
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PMID:Mediastinal widening associated with fractures of the upper thoracic spine. 200 82

Infrarenal aortic occlusion in rabbits to produce paraplegia is possible in large series and can be achieved without any side-effects of anesthetic drugs. This model was tested for its suitability to investigate the use of calcium-channel blockers, which potentially reduce or prevent ischemic spinal cord damage. In a pilot study 26 rabbits were treated with 0.1 mg/kg Flunarizine i.v. prior to occlusion and 38 animals served as control. Groups were compared where the aorta was occluded for 10, 15, 20, 25 or 30 min. No reduction of paraplegia in the Flunarizine groups was observed, apart from in the 15-min occlusion subset: here the number of unaffected animals was significantly greater (p less than 0.05). At histopathological examination the number of ischemic spinal cord segments was reduced (p less than 0.03). It is concluded that Flunarizine could not reduce the cellular damage of the spinal-cord due to complete and global ischemia after an aortic occlusion interval exceeding 15 min. The narrow interval between potential recovery (15 min) and definite paraplegia (20 min) makes this rabbit paraplegia model less appropriate for testing of calcium-channel blockers which are presumed to have a moderate effect on the reduction of spinal cord ischemia.
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PMID:Infrarenal aortic occlusion in the rabbit to assess the effect of flunarizine in the prevention of ischemic spinal cord injury. 201 46

To clarify the cause of delayed-onset paraplegia, the authors evaluated the neurologic outcome after temporary (10 to 30 minutes) spinal cord ischemia in the awake rabbit. Loss of motor function occurred in less than 2 minutes in all animals. Restoration of flow within 16 minutes always resulted in full return of function, whereas with occlusion times of greater than 27 minutes all animals remained paralyzed. After temporary occlusion of 20 to 21 minutes, however, 71% of animals returned to normal neurologic function but developed delayed-onset paraplegia 14 to 48 hours later. This appears to be a reliable method for the creation of a model of delayed-onset paraplegia in the awake animal, and will facilitate more detailed studies of the pathophysiology of ischemia-induced paraplegia.
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PMID:The influence of severity of spinal cord ischemia in the etiology of delayed-onset paraplegia. 202 62

Fifty-seven patients underwent repair of atherosclerotic thoracoabdominal aortic aneurysms between 1978 and 1990. Five patients had urgent surgery for rupture. The 30-day operative mortality rate for the entire group was 18% (10 patients). Before July 1987, 19 patients (group 1) were operated on by use of a technique previously described. In these earlier patients the peritoneum was routinely entered, the diaphragm was divided radially, and no heparin was given. Among patients in group 1 there was a 30-day operative mortality rate of 42% (8 patients), and morbidity included myocardial infarction 4 (21%), respiratory failure 9 (47%), renal failure 12 (63%), bleeding requiring reoperation 4 (21%), and intestinal ischemia 3 (16%). Since July 1987 a standardized approach to all elective thoracoabdominal aortic aneurysms has been used in 38 patients (group 2). This method uses a left thoracoabdominal incision, circumferential division of the hemidiaphragm, retronephric totally extraperitoneal aortic exposure, single lung anesthesia, full heparinization, the graft inclusion technique, and liberal use of visceral endarterectomy. Patients in group 2 sustained a 30-day operative mortality rate of 5% (2 patients) and morbidity included myocardial infarction 2 (5%), respiratory failure 10 (26%), renal failure 11 (29%), bleeding requiring reoperation 1 (3%), paraplegia 6 (16%), and paraparesis 4 (11%). Modern surgery for repair of thoracoabdominal aortic aneurysm results in acceptably low operative mortality rates. Spinal cord ischemia remains an unresolved source of morbidity.
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PMID:Evolving experience with thoracoabdominal aortic aneurysm repair at a single institution. 203 2

Paraplegia after thoracic aortic aneurysm repair has an incidence of 2.2% to 24%. Oxygen-derived free radicals after reperfusion of an ischemic spinal cord may be partly responsible for neuronal destruction. We studied the effects of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), a free radical scavenger, as a way of increasing spinal cord tolerance to ischemia. Thirty rabbits underwent 40 minutes of aortic occlusion (a known model of paraplegia). Ten of these animals received 25,000 U/kg of PEG-SOD 24 hours before aortic occlusion and two additional doses of 10,000 U/kg, one before and one subsequent to spinal ischemia. Ten animals received superoxide dismutase in the same dosages as those receiving PEG-SOD. Ten control animals received placebo. All animals were studied for 96 hours, at which time a final neurological examination was performed and the results were recorded. Of the 10 animals treated with PEG-SOD, 2 were completely paralyzed whereas 8 had less (7) or no (1) neurological impairment. Eight of the 10 control animals and 9 of the 10 animals receiving superoxide dismutase were completely paralyzed. None of the control animals or animals receiving superoxide dismutase had a normal neurological examination (p less than or equal to 0.05). Treatment with PEG-SOD before and during occlusion increased the rabbit spinal cord tolerance to a 40-minute ischemic insult. Scavenging free radicals may lessen experimental spinal cord injury.
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PMID:Reducing postischemic paraplegia using conjugated superoxide dismutase. 203 20


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