[Myocardial infarction in patients under 40 years of age: possible etiopathogenic mechanisms].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
E Ascer
Publications and source records attributed to E Ascer.
[Total abnormal pulmonary venous return. Presentation of 6 cases with variations in the radiologic "snowman" image].
Explore the source record for details and available documents.
Adolescent↗
Does iloprost mediate thromboxane activity and polymorphonuclear leukocyte sequestration in ischemic skeletal muscle?
Thromboxane is known to alter the endothelial cytoskeleton, thereby causing increased endothelial permeability and polymorphonuclear leukocyte (PMN) sequestration in the lungs. We investigated whether iloprost (a stable prostacyclin analog) can decrease thromboxane activity and consequently PMN sequestration because of its anti-platelet aggregation effect. This premise was investigated in a canine isolated gracilis muscle model using 18 animals. Six animals (group I) had the gracilis muscle subjected to 6 hours of complete ischemia followed by 48 hours of reperfusion. Group II (n = 6) received intravenous infusion of iloprost (0.45 micrograms/kg/hr) throughout the experiment (1 hour preischemia, 6 hours of ischemia and 1 hour of reperfusion) and boluses of 0.45 micrograms/kg 10 minutes before ischemia and reperfusion. Group III (n = 6) underwent a similar ischemic interval, but were given iloprost bolus of 0.45 micrograms/kg followed by intravenous infusion of 0.45 micrograms/kg/hr during 48 hours of reperfusion. Gracilis venous samples were obtained at preischemia (PI) and 1 hour of reperfusion (all 3 groups) and at 48 hours of reperfusion (groups I and III) to measure thromboxane (TXB2) levels. Muscle biopsies were taken at the same time to measure myeloperoxidase (MPO) activity, a marker of PMN infiltration. In group I, TXB2 level increased from a pre-ischemic value of 2983 +/- 1083 pg/ml to 9483 +/- 2218 pg/ml at 1 hour of reperfusion (p < 0.05) and then decreased to 2386 +/- 1533 pg/ml at 48 hours of reperfusion (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Do cytokines play a role in skeletal muscle ischemia and reperfusion?
Cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF) are known to mediate host cell response to sepsis, trauma, and myocardial ischemia. We have previously found increased levels of IL-1 in the venous effluent during the reperfusion phase of skeletal muscle ischemia in a canine model. This study was done to evaluate whether TNF also played a role in skeletal muscle ischemia-reperfusion injury since IL-1 and TNF have inter-related functions. In twelve adult mongrel dogs (28-32 kg) one gracilis muscle was subjected to six hours of normothermic ischemia followed by normothermic reperfusion. The contralateral side served as a control and remained normally perfused throughout the experiment. Gracilis venous samples were collected at pre-ischemia and one hour of reperfusion. Systemic (arterial) blood samples were taken simultaneously with the venous samples at one hour of reperfusion. At the end of the experiment the muscles were harvested and amount of necrosis quantitated by serial transections, nitroblue tetrazolium staining and computerized planimetry. Muscle necrosis on the experimental side was found to be 48.86 +/- 5.37%. Sera were analyzed for TNF activity using a bioassay. TNF levels in the gracilis venous effluent at one hour of reperfusion were not significantly different from the simultaneous systemic (arterial) levels (27.15 +/- 5.05 pg/ml vs 18.23 +/- 4.27 pg/ml). Pre-ischemic levels of TNF were 96.50 +/- 20.12 pg/ml, which was significantly higher than either venous or arterial levels obtained after one hour of reperfusion (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Initial experience with the "Smart" laser in the treatment of atherosclerotic occlusions.
A dual laser system capable of distinguishing atherosclerotic plaque from components of normal arterial wall was used to deliver laser energy to cut a channel through occluded vessels. This system was used to facilitate balloon angioplasty of short (3-17 cm) total occlusions of the superficial femoral or popliteal arteries in 17 patients. In 10 patients the occluding lesion was traversed by the laser wire and patency was effectively restored by balloon angioplasty. Satisfactory luminal patency has persisted for 2 to 12 months (mean 6 months) in 9 cases; the lesion in the tenth patient restenosed at 3 months. The laser procedure was unsuccessful in all 3 cases with occlusions over 10 cm and in 4 others. There were no clinically important complications. This experience suggests that most patients who presently require interventional treatment can be managed by standard angioplasty methods and/or require a bypass operation. The "Smart" laser is safe and effective short-term in facilitating angioplasty in some patients in whom standard angioplasty techniques are not feasible. The implications of these findings are discussed.
Angiography↗
The effect of adjunctive arteriovenous fistula on prosthetic graft patency: a controlled study in a canine model.
Bilateral 6 mm PTFE grafts were placed from the external iliac artery to the femoral artery with ligation of the intervening segment of the iliofemoral artery in 14 dogs. An arteriovenous fistula was constructed at the distal anastomosis on one randomly selected side in each animal while the contralateral graft served as a control. Graft follow-up ranged between 8 and 12 months in all animals. Serial arteriography was performed to confirm graft and fistula patency and demonstrated persistence of antegrade flow into the arterial tree distal to all patent bypasses. Femoral intraarterial pressures distal to patent grafts were identical on both sides in each animal throughout the study. Cumulative life-table patency rates showed higher patency for the arteriovenous fistula bypasses than the control grafts at all time intervals: 71% vs. 57% at 3 months, 48% vs. 25% at 6 months, and 40% vs. 22% at 12 months, respectively. This is the first controlled study that provides experimental evidence suggesting that these bypasses may produce increased patency of prosthetic arterial grafts and lends support to their use in a clinical, prospective, randomized study.
Animals↗
Photoplethysmographic evaluation of external compressive therapy for chronic venous ulceration.
The photoplethysmograph (PPG) was utilized to evaluate the role of external compression in the treatment of chronic venous insufficiency with ulceration (CVIU). Thirty patients with long standing CVIU were evaluated using a PPG probe placed just above the medial malleolus. Venous recovery time (VRT) was calculated after 5 active dorsiflexions. Patients were then retested after an Unna boot had been applied and again, after this had been supplemented by a tight elastoplast wrap. VRT in 10 normal control subjects was greater than 12 seconds (12-30 seconds, mean 19+/-5 seconds). VRT was less than 12 seconds in all tested patients (0-11 seconds, mean 5+/-2 seconds). When an Unna boot was applied, VRT increased to 7+/-2 seconds in 20 patients. An Unna boot and elastoplast wrap increased VRT to 10+/-3 in 25 patients (p less than 0.01).
Bandages↗
Five year experience with axillopopliteal bypasses for limb salvage.
Over the last 5 years, we have performed 34 axillopopliteal bypasses to salvage threatened limbs of patients in whom standard anatomic or extra-anatomic bypasses had either failed or were not feasible. The indications for these axillopopliteal bypasses, all of which were performed with 6 mm polytetrafluoroethylene grafts, were: (1) severe atherosclerotic disease of the common, superficial and deep femoral arteries which precluded use of these vessels for inflow or outflow for a standard vascular procedure (15 cases); (2) failed aortofemoral bypass with sufficient fibrosis or disease progression in the profunda femoris artery to prevent its use in a reoperation (7 cases); (3) insufficient hemodynamic improvement and failure to heal a foot lesion after an axillofemoral bypass (9 cases); and (4) sepsis in the groin from a previously infected bypass (3 cases). Graft patency was determined by objective measures. Cumulative life table graft patency rates were 77% at 1 year, 51% at 3 years, and 45% at 5 years. Although these rates are not as good as those for our axillofemoral bypasses (75% at 5 years), 22 limbs revascularized by axillopopliteal bypasses were salvaged with function for 1 year and 9 were salvaged with function for 2 years or longer in situations in which no option other than amputation was available. This justifies the continuing use of axillopopliteal bypass in an effort to salvage those limbs imminently threatened with amputation and in which no standard reconstruction is feasible because of disease or infection.
Aged↗
Six year experience with expanded polytetrafluoroethylene arterial grafts for limb salvage.
We have used 822 polytetrafluoroethylene (PTFE) grafts in arterial reconstructions for limb salvage over the last 6 years at Montefiore Medical Center-Albert Einstein College of Medicine, Four hundred and twenty-seven femoropopliteal reconstructions with PTFE had a 6 year cumulative life table patency rate of 55% with follow-up of 76 grafts for more than 3 years and 28 grafts for more than 4 years. Seventy-nine bypasses to the isolated popliteal segment had a 6 year cumulative patency rate of 72%. There were 207 bypasses performed to the tibial, peroneal or dorsalis pedis arteries. Life table patency rates were 55% at 1 year, 40% at 2 years and 37% at 4 years. Ninety-two PTFE femorofemoral and 62 axillofemoral bypasses had 5 1/2 year cumulative life table patency rates of 83% and 75%, respectively. Axillopopliteal PTFE bypasses can salvage otherwise doomed limbs. Thirty-four such grafts had 74% 1 year and 45% 5 year patency rates. The overall infection rate in all 822 PTFE grafts was only 0.5%. Thus, PTFE is a promising vascular prosthetic material which facilitates otherwise difficult or impossible limb salvage procedures.
Adult↗
Diagnosis and management of failing lower extremity arterial reconstructions prior to graft occlusion.
In 191 instances, infrainguinal graft occlusion was presumed because of a rethreatened foot, diminished pulses and/or decreased ankle pressure. Routine urgent arteriography revealed 38 instances where the graft was patent (22 vein, 16 PTFE). Ten of these grafts were to the femoral artery, 18 to the popliteal artery and 10 were to infrapopliteal arteries. The deterioration despite a patent graft was due to development of inflow stenosis (15), vein graft lesions (13) or distal disease progression (10). All were treated successfully by percutaneous transluminal angioplasty (30) or simple local operative revisions (8). Cumulative life table patency rates 2 years after reintervention were 89% for failing reconstructions to the femoral artery, 94% for those to the popliteal artery and 89% for infrapopliteal procedures. Comparable rates for limb salvage were 90%, 100% and 100%, respectively. These findings underscore the importance of urgent angiography in suspected lower extremity graft failure. Defects may be detected before real graft occlusion occurs and appropriate interventional treatment can provide important additional periods of limb salvage.
Angioplasty, Balloon↗