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Biomedical subjects

J S Vasko

Publications and source records attributed to J S Vasko.

At least 37 records · Page 2Linked to original sources
PubMed1979

Hypertension following carotid endarterectomy.

Seventy-nine patients undergoing staged bilateral carotid endarterectomy were studied to determine the relationship of perioperative hypertension to postoperative neurologic deficits. Six of the eight neurologic deficits following 158 endarterectomies (5%) occurred after the first operation, all being temporary. Comparison of the mean blood pressures in patients with and without postoperative strokes revealed no statistically significant differences. Patients on antihypertensive medications were at a significantly higher risk of developing postoperative strokes. A trend towards higher blood pressure was noted following the second endarterectomy, particularly when they were staged more than 60 days apart. Based on our findings, a cautious approach is warranted in the treatment of postendarterectomy hypertension.

Adult↗
PubMed1978

Safety and rationale for continuation of propranolol therapy during coronary bypass operation.

Thirty consecutive patients undergoing coronary bypass were studied. Oral propranolol therapy was maintained up to 4 to 10 hours before operation. Nineteen of the patients had a history of myocardial infarction (MI), 14 had hypoakinetic areas, and 8 had decreased ejection fraction indicating advanced coronary artery disease. Twenty-four-hour urinary epinephrine and norepinephrine obtained the day before operation were markedly increased at 136 +/- 12 microgram per 24 hours (normal, 39 +/- 4 microgram, rho less than 0.01). There were 4 perioperative MIs (13%) and no deaths. Plasma propranolol 1 hour before operation was 43.3 +/- 8 ng per milliliter, indicating good beta blockade. Propranolol was started within 24 hours postoperatively. There were no preoperative, intraoperative, or postoperative complications related to propranolol therapy. We conclude that because of markedly increased adrenergic tone the day before operation and transient hypersensitivity to adrenergic stimulation after withdrawal of propranolol, this agent should be continued through coronary bypass operation.

Adult↗
PubMed1978

Late failure in vein grafts: mediating factors in subendothelial fibromuscular hyperplasia.

Late failure of autologous vein grafts often results from excessive subendothelial fibromuscular hyperplasia. Varying factors have been implicated in this process, but the exact etiology remains unclear. In this study, three groups of animals were studied which had sections of common carotid artery replaced with autologous vein grafts. Group I had simple replacement, while Groups II and III had grafts supported by either tightly woven or loose mesh dacron prostheses. Thrombosis occurred only in the unsupported grafts. Unsupported grafts also had more subendothelial proliferation when compared to the loose mesh group. The combined thickness of the intima-media correlated inversely with the number of vasa present within the vein graft wall, i.e. significantly more vascularization was found in the mesh supported group when compared to the other groups. Grafts supported with the tightly woven prosthesis were relatively impervious to the ingrowth of vasa vasora. The data suggest that persistent distension of the graft wall by intra-arterial pressure influences the degree of subendothelial fibromuscular hyperplasia and may be interrelated to revascularization of the graft wall per se.

Animals↗
PubMed1978

Prevention of stroke by carotid endarterectomy.

Cerebral stroke can occur in patients having visual symptoms only. Fundoscopy is valuable in identifying those patients with visual symptoms who are likely to have carotid disease; and carotid endarterectomy can prevent a stroke in a significant percentage of patients at risk. Meticulous operative technique is essential. In a series of 187 carotid endarterectomies performed on 154 patients over a 7-year period, the operative mortality rate was zero. Operative morbidity was 1.3% in 139 patients who had no prior permanent neurological deficits, and 13% in 15 patients who had suffered previous strokes. Data compiled on follow-up for an average of 20 months indicated that six patients (4.7%) suffered postoperative strokes, nine patients (7%) experienced persistence of symptoms, and 113 patients (88.3%) remained neurologically well.

Aged↗
PubMed1978

Role of staging in bilateral carotid endarterectomy.

Staging of bilateral carotid endarterectomies 1 to 6 weeks apart has been recommended because of presumed excessive morbidity chiefly related to respiratory problems, hypertension, and neurological deficits. Since data regarding the timing of the second procedure are lacking, an analysis of 79 consecutive patients undergoing bilateral endarterectomies staged from 6 days to 34 months apart (median interval, 52 days) was performed. In addition to postoperative neurological deficits, however, transient perioperative mean systolic and diastolic blood pressures (SBP and DBP) were compared after each side and were correlated with the time interval between the two procedures. No significant difference existed between the two sides in terms of preoperative hypertension, administration of steroids prior to clamping, intraoperative clamp time, the use of shunts, and the duration of operation (P greater than 0.05). Seven temporary neurological deficits occurred after operation, six after the first and one after the second endarterectomy. One permanent deficit following operation on the second side led to the only death (0.6%) in this series. Both neurological deficits (one temporary and one permanent) following the second endarterectomy occurred after procedures staged more than 60 days apart. No differences in mean SBP and DBP existed between patients with and without neurological deficits. Statistical analysis of SBP and DBP recordings during and 6, 12, 24, and 36 hours after operation when the two were staged 7 days (nine patients), 8 to 14 days (five patients), 15 to 30 days (10 patients), 30 to 60 days (17 patients), and more than 60 days (38 patients) apart revealed significantly higher readings after the second procedure, only in patients staged greater than 60 days (P less than 0.05). Therefore, in our experience, neurological deficits were less common after the second endarterectomy, and, although postoperative blood pressures were higher after the second side, these were significant only in patients staged more than 60 days apart. We find no evidence to suggest that increasing the waiting period between bilateral procedures will lower the incidence of undesirable neurological sequelae.

Arterial Occlusive Diseases↗
PubMed1977

Counterpulsation catheter fracture: an unexpected hazard.

This paper presents a previously unrecognized hazard associated with intraaortic balloon pumping: fracture of the catheter due to chemical damage by acetone at the time of removal. Common hospital chemicals such as acetone, ether, and Vi-Drape spray may damage the catheter. Contact between these agents and polyurethane intraaortic balloon catheters should be avoided during dressing changes or repreparation of a sterile operative field. Isopropyl alcohol, Betadine, benzoin, and Cidex do not damage the catheter.

Acetone↗
PubMed1977

Preservation of the ischemic leg by distal vascular bypass.

Autogenous saphenous vein bypass grafts to tibial or personeal vessels have resulted in successful, long-term limb preservation in appropriately selected patients. This success appears to justify an aggressive approach to what has previously been considered end-stage" distal vascular occlusive disease. This report describes the clinical management and long-term follow-up of 41 patients with tibial artery reconstruction.

Adult↗
PubMed1977

Nonpenetrating trauma to the thoracic aorta.

Twenty-seven patients underwent surgical repair for nonpenetrating injuries of the thoracic aorta. Emergency operation was performed in 19 patients with acute aortic injury and there were 12 survivors. Left heart bypass (LHB), external shunts, and simple aortic cross-clamping were methods employed during repair. All operative deaths occurred in the left heart bypass group. Morbidity, hospital stay, operative time, and blood loss all were markedly less in patients repaired with an external shunt or simple cross-clamping. Systemic heparinization related adversely to mortality and morbidity. Eight patients had repair of chronic post-traumatic descending aortic aneurysms. One of these had previous repair elsewhere with paraplegia and subsequent mycotic aneurysm at the graft repair site. He presented to us with massive hemoptysis. Surgical correction in the chronic group was performed using either left heart bypass, external shunt, or simple aortic cross-clamp with graft interposition. The only death occurred in a patient repaired on left heart bypass.

Adolescent↗
PubMed1977

The role of multiple noncritical arterial stenoses in the pathogenesis of ischemia.

The hemodynamic effects of multiple noncritical lesions in series were studied in in vitro experiments and in 15 animals. Flow visualization studies were also carried out to obtain insight into the flow pattern in the region of stenosis. Symmetrical stenosis pieces with a 50 per cent reduction in area were placed inside a plexiglass tube and used for both in vitro and in vivo experiments. Varying the number of stenoses and the spacing between them enabled us to study twelve different stenosis configurations during both pulsatile and steady flow. Flow conditions encountered clinically were simulated by varying the average Reynolds number between 30 and 380. Pressure drops across the stenosis test section were measured with a differential pressure transducer and used to calculate critical values for multiple, uniform, noncritical stenoses and for combinations of stenoses of different degrees. Results from steady and pulsatile flow in vitro were comparable, as were those results from the in vivo experiments. The pressure drop across a series of noncritical stenoses was nearly the sum of the individual pressure drops, with only slight dependence upon the spacing between stenoses, Thus it is concluded, from both experimental results and from the theoretical calculations, that the total effect of a series of noncritical stenoses may become critical and produce symptoms of arterial insufficiency.

Animals↗
PubMed1977

Surgical management of the totally occluded carotid artery.

Surgical revascularization of the completely occluded carotid artery was evaluated in 19 symptomatic patients who had recurrent episodes of amaurosis fugax or transient hemiparesis. Nine had complete internal carotid occlusion on arteriography and 10 had severe stenosis which had progressed to total occlusion by the time of surgical exploration. At operation irreparable fibrotic changes were observed in four patients, but in 15 a pattern of proximal focal obstruction with relatively healthy distal internal carotid vessels was observed. Thromboendarterectomy produced good back-bleeding in most of these and resulted in improved carotid flow after operation. Seventeen of 19 patients were relieved of symptoms. Two patients continued to have symptoms, but less frequently. There were no deaths after operation. Follow-up from 3 to 36 months showed no change from immediate postoperative results. This study suggests that carotid artery exploration and thromboendarterectomy should be considered when transient ischemic episodes are present despite complete internal carotid artery occlusion.

Arterial Occlusive Diseases↗
PubMed1976

Narrow lumbar spinal canal with "vascular" syndromes.

Symptoms suggestive of vascular origin, both venous and arterial, may be the presenting complaints in patients with lumbar spondylosis. Fourteen patients suspected of having vascular intermittent claudication were found to be free of vascular disease, but had cauda equina compromise from herniated disk, osteoarthritis, and hypertrophic ligaments. Complete follow-up data were available for seven patients. In three, claudication seemed typical; in four, atypical. At operation, herniated intervertebral disks, osteophytic bone, or hypertrophied ligamenta flava, or a combination, were found. All benefited from lumbar laminectomy. When patients with vascular-like symptoms are found to be free of arterial or venous disease, lumbar spondylosis (narrow lumbar canal syndrome) should be considered. Chronic incapacitation pain without vascular disease provides a clue, as does electromyography. Plain X-ray films of the lumbar spine do not show the abnormality; thus, myelography should be carried out even in the absence of neurologic signs.

Aged↗
PubMed1976

Left ventricular function and adrenergic hyperactivity before and after saphenous vein bypass.

Forty patients with severe angina pectoris were studied before and two weeks after saphenous vein bypass surgery (SVG) in order to assess the effect of this operation on left ventricular performance as judged by systolic time intervals (STI). The patients were divided into two groups: group I included 29 patients in whom no postoperative infarction occurred and group II was composed of 11 patients with postoperative infarction. For group I the PEP/LVET was 0.39 +/- 0.01 preop and slightly but significantly increased at 0.42 +/- 0.004 (P less than 0.025) two weeks postop. The mean preop PEP/LVET was 0.33 +/- 0.01 for group II and dramatically increased to 0.54 +/- 0.02 (P less than 0.001) after surgery. Another striking abnormally was a marked shortening of electromechanical systole (QS2I), which was uniformly present in the postoperative studies. Follow-up studies in 16 patients and urinary catecholamine determination in five patients suggested excessive adrenergic activity was responsible for the abbreviated QS2I. This phenomenon must be considered when interpreting the results of SVG on left ventricular function.

Adult↗