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

During 1980, 30 patients underwent successful operations for ascending thrombosis of the abdominal aorta in its three forms: low (below the inferior mesenteric artery, 11 patients); middle (above the inferior mesenteric artery, 6 patients); and high (at the level of the renal arteries, 13 patients). An angiogram that reveals high ascending thrombosis of the abdominal aorta is paradoxically more favorable than one that reveals middle or low ascending thrombosis of the abdominal aorta. In fact, the patient with a juxtarenal thrombosis has already overcome two of the three phases that constitute the critical moments of potential failure of the collateral circulation. Progressive ascending thrombosis with a poor prognosis and a rapidly downward course can cause acute ischemia with paraplegia of the legs and intestinal infarction. Most patients die suddenly in the emergency or intensive care unit from paraplegia, acute abdomen, or anuria; the latter is due to further progressive thrombosis with obstruction of the orifice of the renal arteries. On the basis of the angiogram only (apart from subjective symptoms), ascending thrombosis of the abdominal aorta constitutes an absolute indication for surgical treatment.
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PMID:Natural history of ascending thrombosis of the abdominal aorta. 684 5

Ischemia is the pathophysiological mechanism in many types of spinal cord injury. In the present study, the infrarenal segment of the aorta was occluded for 25 minutes to produce spinal cord infarction in rabbits. Paraplegia occurred in 100% of control animals. Thiopental administered before aortic occlusion resulted in paraplegia in only 40% of animals so treated (p less than 0.01). Histological study of the spinal cord demonstrated infarction of the gray matter in all paraplegic animals, whereas the microscopic appearance was normal in animals without neurological deficit. The protective influence of thiopental therapy in spinal cord ischemia was demonstrated.
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PMID:Barbiturate protection in acute experimental spinal cord ischemia. 706 21

Paraplegia has been an unpredictable, devasting complication following operations upon the thoracoabdominal aorta for over 30 years. The frequency ranges from 0.5% with operations for coarctation to as high as 15% following surgery for thoracoabdominal aneurysms. Both uncertainty and controversy exist about the value of different protective methods during aortic crossclamping (AXC): heparinized shunts, partial bypass, and reimplantation of intercostal arteries. This report describes the authors' initial clinical experience with a highly sensitive indicator of spinal cord ischemia, somatosensory evoked potentials (SEP) in an attempt to prevent paraplegia associated with surgical procedures on the thoracoabdominal aorta. Seven consecutive patients (one coarctation, five thoracic aneurysms, one thoracoabdominal aneurysm) underwent continuous operative monitoring of SEP. Cortical response to simultaneous electrical stimulation (20 mAmps, 0.6 mSec., 2.3 cps) of both the right and left posterior tibial nerves was recorded before, during, and after AXC, and following operation. When ischemic changes were detected by SEP, increasing distal circulation by different maneuvers (heparinized shunt, femoral-femoral bypass, reimplantation of intercostal arteries) reversed these changes. In two patients with thoracic aneurysms, ischemic changes appeared within three minutes after AXC and all potentials disappeared in nine minutes. Rapid insertion of a graft (AXC 28 and 37 minutes) resulted in SEP return 40 minutes following restoration of flow. These changes were prevented by a heparinized shunt in two patients, femoral/femoral bypass in one, and T8-T9 intercostal reimplantation in one. No SEP changes occurred in the patient with coarctation. No postoperative neurologic complications occurred. Continuous operative monitoring of SEP has exciting possibilities for preventing paraplegia. It is simple, highly sensitive, and seems to provide a precise measurement of adequacy of circulation to the spinal cord.
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PMID:Measurement of spinal cord ischemia during operations upon the thoracic aorta: initial clinical experience. 711 35

Paraplegia remains a devastating and unpredictable complication of surgical procedures requiring temporary occlusion of the thoracic aorta, interruption of important spinal radicular vessels, or both. Intraoperative monitoring of the physiological integrity of the spinal cord should permit the early detection of spinal cord ischemia, the judicious and timely institution of corrective measures, including bypass or shunting, and the preservation of important intercostal arteries in appropriate circumstances. A model of spinal cord ischemia was created by temporary proximal and distal occlusion of the canine thoracic aorta. Serial measurement of somatosensory cortical evoked potentials (SCEP) generated by peripheral nerve stimulation, reflecting the status of long-tract neural conduction, was used to monitor alterations in spinal cord function during ischemia. Twelve animals subjected to aortic occlusion demonstrated a characteristic time-related deterioration of the SCEP with virtual extinction of the signal at a mean interval (+/- standard error of the mean) of 12.4 +/- 1.5 minutes. Six animals in which reperfusion was established immediately following the loss of the SCEP (Group 1) demonstrated complete recovery without neurological sequelae, as assessed by clinical and histological criteria. In 6 animals (Group 2), the period of aortic occlusion was extended for an additional 15 minutes following loss of the SCEP (27.3 +/- 2.3 minutes); postoperatively, 4 of 6 animals sustained major neurological lesions characterized by spastic paraplegia and histological evidence of spinal cord infarction (Group 1 versus Group 2, p less than 0.05). We conclude that distinctive alterations in the SCEP are indicative of reversible ischemic spinal cord dysfunction. On-line monitoring of spinal cord function using the technique of SCEP provides a rational basis for determining of SCEP provides a rational basis for determining operative strategy during surgical procedures on the thoracic aorta.
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PMID:Intraoperative detection of spinal cord ischemia using somatosensory cortical evoked potentials during thoracic aortic occlusion. 711 48

The experience in the surgical treatment of traumatic rupture of the thoracic aorta is discussed. Twenty-two patients were seen from 1970 to 1980. They were divided into three groups, according to delay between injury and aortic repair: 1 degree emergency group: 16 patients; 2 degree delayed group: 3 patients; 3 degrees chronic group: 3 patients. All patients had a widened mediastinum and the aortography confirmed the diagnosis. In the first group four patients died before surgery could be started and four after aortic repair from 10 days to 6 seeks postoperatively. In the second and third group all patients survived. Of 22 cases, 21 ruptures were located at the aortic isthmus and 1 at the aortic arch. Many patients had various other injuries, skeletal, abdominal or cerebral. All, but one patient, were operated with the aid of a partial pulsatile left heart bypass to avoid cerebral hypertension and cardiac overload, and to prevent kidney and spinal cord ischemia. One patient was operated, according to the method of Crawford, with blood pressure controlled with nitroprusside. We have not observed in our patients paresis or paraplegia after surgery. The hospital mortality of the surgical treated patients was 34% in the emergency group and 0% in the delayed and chronic group. Surgical treatment is essential in emergency situation, as a complete rupture may be fatal and repair of the chronic post-traumatic false aneurysm is advocated, as their prognosis is unpredictable.
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PMID:Traumatic rupture of the thoracic aorta. 714 91

A case of paraplegia occurring during surgery for coarctation of the aorta in a 28 month-old child is reported. Paraplegia was due to medullary ischemia, probably related to insufficient collateral circulation. Such ischemic accidents generally remain unforeseeable and no good prevention is available. This rare operative complication should not alter the present management of coarctation of the aorta.
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PMID:[Paraplegia complicating surgery for coarctation of the aorta]. 715 62

Acute surgical decompression accompanied by stabilization and fusion is a safe procedure in patients with spinal cord injury. No patient was made worse by surgery. Patients with partial preservation of function and myelographic defects, i.e., surgical candidates, made better recoveries than those with normal myelograms who were, therefore, not operated upon. These results probably signify greater intrinsic cord damage in the nonsurgical group, but confirm the safety of surgery. We doubt the value of decompression for swollen cords except where there are hematomas. The treatment of cord swelling and ischemia will depend on improved pharmacological regimens.
J Am Paraplegia Soc 1982 Apr
PMID:Early surgical management of acute spinal cord injury. 718 21

One case of traumatic rupture of the isthmic region of the aorta is reported. Acute ischemia of the inferior limbs, anuria and paraplegia have led to the diagnosis. During the first hours after the trauma bowel ischemia appeared. The repair of the aorta was achieved within the seven hours after the accident but the bowel ischemia stayed irreversible. A such complication has not been reported in the literature as long as we know and we are think that it is possible to range this complication among some of the ischemic enterocolitis.
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PMID:[Traumatic rupture of the isthmic region with bowel ischemia (author's transl)]. 721 31

Metabolic alterations after experimental contusion injury of the spinal cord were evaluated by determining qualitative spinal cord glucose utilization (SCGU), SCGU was determined by the 2-deoxy-D-[14C] glucose technique. An increase in SCGU occurred at the site of maximal impact in the white matter after an injury causing paraparesis and in near trauma regions after an injury causing either paraparesis or paraplegia. These findings are most likely due to anaerobic glycolysis resulting from a reduction in blood flow that still allows delivery of substrate to tissue. Although an initial increase was observed at the site of maximal impact after a paraplegia-causing injury, SCGU in the white matter demonstrated a progressive deterioration by 4 and 8 hours after injury. A failure of substrate delivery resulting from ischemia is the most likely cause for this reduction in SCGU. The somatosensory evoked potential was found to be a very sensitive indicator of the remaining functional axons at the injury site.
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PMID:Spinal cord glucose utilization after experimental spinal cord injury. 727 71

Numerous investigators endeavored to make clear pathophysiological changes in a traumatic spinal cord lesion. The development of neuroscience contributed to have an influence on methods of these researches. This study was undertaken to assess electrophysiological changes resulting from variable periods of experimental spinal cord compression or ischemia by using the evoked spinal cord potentials. Experiments were performed on dogs. Following laminectomies at Th7-9 and L3-4 levels under anesthesia, cord injuries were produced at the lower thoracic level by inflation of an extradurally placed balloon which produced slow graded compression of cord dorsum. Evoked spinal cord potentials to sciatic nerve stimulation were recorded from bipolar electrodes in the midline dorsal subdural space at the operative sites. The normal wave forms of two responses consisted of initially positive triphasic potentials (P1, N1, P2). The conduction velocity of the ascending afferent from the leg was found on the average to be 54.8 +/- 9.7 m/sec between lumbar and dorsal cord. On the basis of the conduction velocities and the responses to stimulus intensities, the afferent volley recorded in the present experiments might reflect synaptic cord afferent pathways originated without Group I fibers in the cord dorsum which were situated ipsilateral to the stimulated nerve. After inflation of the balloon with 0.1 cc of water, spinal canal narrowing rate increased to 14.3 +/- 2.9%. The evoked spinal cord potentials in the lead rostral to the site of compression began to decrease in amplitude. When more water was added into the balloon up to 0.4 - 0.6 cc, spinal canal narrowing rate was enhanced to 42.5 - 77.7% in which potentials were abolished. P2 wave was the first to be abolished and subsequently N1, P1 disappeared in order. On the other hand, the potentials reappeared after decompression in the reverse of their disappearance in order. Responses in dogs with complete recovery from paraplegia returned to the precompression wave pattern both in the amplitude and in latency. On the contrary, in dogs with spastic paraparesis, the recovery of wave form was shown as P1, N1 or P1, N1 with depressed P2. Despite this variability, the evoked response from animals with reversible cord injury were discernible in the early period of spinal shock phase. The degree of recovery varied and had no linear relationship to the recovery grade of clinical symptoms. The experimental cord ischemia was made by inflation of a balloon catheter which was inserted from femoral artery into the upper thoracic aorta. The evoked spinal cord potentials were recorded at the midthoracic and lumbar level. Changes of wave form resulting from the ischemic period of 30 minutes were first the amplitude loss of N1 and subsequently that of P2, P1. On the other hand, the responses gradually returned to their pre-ischemic characteristic about 30 minutes after circulatory reestablishment...
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PMID:[Clinical application of the evoked spinal cord potentials. Part 1. Neurophysiological assessment of the evoked spinal cord potentials in experimental cord trauma - with reference to cord compression and ischemia (author's transl)]. 728 22


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