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Biomedical subjects

D E Strandness

Publications and source records attributed to D E Strandness.

At least 181 records · Page 10Linked to original sources
PubMed1984

Pentoxifylline in the treatment of intermittent claudication of the lower limbs.

Pentoxifylline, a methyl xanthine analogue was evaluated for treatment of intermittent claudication in a double-blind placebo controlled parallel group study in seven centers in the United States. Tests were performed on 128 cases, including 42 who took pentoxifylline (600 mg by mouth daily, increased stepwise to 1200 mg daily at the end of one month) and 40 who took placebo for 24 weeks. Twenty-five patients on pentoxifylline and 21 on placebo were dropped from the study for reasons unrelated to the drug. Walking ability on a treadmill was increased significantly after 2 weeks and remained so throughout the study in the pentoxifylline vs. the placebo group. Ability to walk until first experiencing intermittent claudication was a more sensitive index than the maximum ability to walk. The drug did not cause changes in blood pressure or in heart rate. Other than mild nausea, there were no significant side effects.

Clinical Trials as Topic↗
PubMed1984

Natural history of carotid artery disease on the side contralateral to endarterectomy.

The natural history of the nonoperated carotid artery opposite an endarterectomy was examined in 134 patients by means of ultrasonic duplex scanning over a period extending to 48 months. None of the nine deaths that occurred during follow-up was stroke related. A total of 22 arteries showed progression of disease over this period. By life-table analysis the mean annual rate of progression for all categories of disease was 12.6% and 7.4% for progression to a diameter reduction greater than 50%. Disease progression was more rapid in patients under 65 years of age. Symptoms occurred in 13 patients for an overall incidence of 10% and a mean annual rate estimated at 5%. All symptoms indicated transient ischemic attacks; there were no strokes. There was a strong relationship between the development of symptoms and stenoses greater than 80% either at the initial examination or secondary to progression. No correlation was found between the presence of bruits or their change over time and the progression or appearance of symptoms. Conservative management of nonoperated vessels opposite an endarterectomy appears appropriate until symptoms develop or a lesion greater than 80% is detected.

Adult↗
PubMed1984

Pathophysiology of venous claudication.

Patients with chronic iliofemoral venous obstruction may develop severe thigh pain and a sensation of tightness with vigorous exercise (venous claudication). The discomfort requires 15 to 20 minutes to subside. In the seven patients studied the venous capacitance (VC) and venous outflow (VO) are lower than those of the unaffected limb even at rest. With exercise to the point of pain, the VO was unchanged but the VC decreased even further. The problem appears to rest with the venous collaterals, which have a high and fixed resistance. Because of this high outflow resistance, venous volume increases to near maximum during exercise. With this rise in venous volume, the amount the VC can increase during the period immediately following exercise is further reduced.

Adult↗
PubMed1983

Long-term sequelae of acute venous thrombosis.

The long-term sequelae of acute deep-vein thrombosis were examined prospectively in a series of 61 patients. The location and extent of the involvement were established by either contrast or isotope phlebography. The mean age of the patients was 47 years, with the duration of follow-up averaging 39 months (range, one to 144 months). Pain and/or swelling was noted in 67% of the patients. Pigmentation developed in 15 limbs (23%). Ulceration developed in three patients. The most important factor with regard to prognosis appeared to be the status of the distal deep veins. If these were found to be patent and competent by ultrasonic velocity studies, the long-term outlook was good, both with regard to symptoms and the development of pigmentation. Only 8% of those limbs with normal distal veins were found to have pigmentation during follow-up, as compared with 40% in those with either occlusion or incompetence of the valves.

Acute Disease↗
PubMed1983

A systematic approach to the assessment of aortoiliac disease.

The accurate localization of hemodynamically significant disease in the aortoiliac segment remains a major clinical dilemma that contributes to the less than optimal results reported for aortofemoral bypass grafting in patients with disabling lower limb claudication. We assessed the hemodynamic status of the aortoiliac segment with direct intraarterial pressure measurements obtained prior to arteriography. This served as a basis for determining the role of the femoral pulsatility index (FPI) in evaluating the hemodynamics of the aortoiliac segment. A stepwise decision making algorithm, developed from the results, enabled accurate identification of the location of the hemodynamic disturbance in 94% of the limbs studied. In 62% of the limbs, the FPI could be used, while in the remaining 38%, intra-arterial pressure measurements were used.

Aorta, Abdominal↗
PubMed1983

Is siphon disease important in predicting outcome of carotid endarterectomy?

The prevalence of atherosclerosis at the carotid bifurcation and in the siphon was reviewed in 141 patients who underwent 149 endarterectomies. The relationship between the presence and severity of siphon lesions and focal neurologic symptoms, both before and after operation, was also examined. Siphon disease was found in 84% of the 282 sides. Most lesions (42%) were in the 20% to 49% diameter-reduction category. Only 9% were stenoses greater than 50%, and 10% were occlusions. The majority (65%) were smooth. No relationship was found between the severity of disease at the carotid bifurcation and in the siphon. No pattern of siphon disease could be related to the occurrence of symptoms. Furthermore, no relation was found between the severity of siphon disease and recurrent symptoms after endarterectomy.

Carotid Arteries↗
PubMed1983

The influence of ultrasonic Duplex scanning on the management of carotid artery disease.

In order to assess the influence of a non-invasive test such as Duplex scanning on the management of patients with suspected carotid artery disease, we reviewed the data on all new referrals (n = 491) during a year. The patients were grouped according to the reason for the referral: 1, patients with focal neurological symptoms lasting less than 24 h (n = 156); 2, patients with focal neurological symptoms lasting longer than 24 h (n = 107); 3, patients with non-focal neurological symptoms (n = 147); 4, patients with asymptomatic bruits (n = 81). For all four groups there was a statistically significant relationship (chi 2; P less than 0 . 005) between the reporting of the presence of a high grade stenosis (more than 50 per cent diameter reduction) and the likelihood that the patient would undergo arteriography. The finding of a high grade stenosis on the arteriogram resulted in a greater number of patients undergoing carotid artery surgery. The results of this study indicate that the report of the non-invasive test influenced the decision-making process in the management of patients with suspected carotid artery disease.

Carotid Artery Diseases↗
PubMed1983

Streptokinase treatment of acute arterial occlusion.

In selected cases, streptokinase, a thrombolytic agent, is an effective alternative to surgical intervention for the treatment of acute arterial occlusions. Successful thrombolysis was achieved in 12 of 16 arterial occlusions (75%) following the intra-arterial infusion of streptokinase at a dosage of 5,000 U per hour. Neither the etiology nor the duration of the occlusions influenced the ability to achieve effective thrombolysis. The major limitation of the technique was the time required to ensure complete thrombolysis (37.5 +/- 17.5 hours). Despite the localized infusion of streptokinase proximal to the arterial obstruction at low dosages, hypofibrinogenemia (100 mg/dl) occurred in five patients and four patients developed a bleeding complication. The use of concomitant heparin (300-500 U per hour) increased the risk of bleeding without increasing thrombolytic potential. Streptokinase treatment of acute arterial occlusions should be used selectively depending on the degree of ischemia, the etiology of the obstruction, and the clinical status of the patient.

Aged↗
PubMed1983

The use of common carotid waveform analysis in the diagnosis of carotid occlusive disease.

Duplex scanning with spectral analysis of the pulsed Doppler signal are currently used to detect and classify disease at the carotid bifurcation. Although the sensitivity of the test exceeds 90%, the method has a lower specificity which ranges between 8 and 50%. The poor specificity is due to the difficulty in distinguishing flow disturbances normally present at the carotid bifurcation from those produced by minimal amount of disease. In order to improve the ability of the method to predict normalcy, new features measured from the low common carotid waveform are evaluated on 150 sides. The difference of frequency from the systolic peak (a) to the point of first zero slope after peak systole (b) was used to define the ratio (a-b)/a. A ratio greater than 0.5 was associated with 76% of the normal sides and only 7% of the diseased sides. A ratio below 0.5 was associated with 83% of the diseased sides. This ratio, when used alone, can improve the specificity of the method to 76%.

Angiography↗
PubMed1983

The impact of Duplex scanning on the evaluation of patients with asymptomatic bruits in the region of the carotid arteries.

Between January 1980 and January 1981, 95 patients with 'asymptomatic' bruits in the region of the carotid arteries were evaluated at the University of Washington with an ultrasonic Duplex scanner combined with spectral analysis. Based upon the interpretation of a hardcopy of the spectral analysis, the artery of interest was classified into one of five categories: A normal; B 5-15% diameter reduction; C 16-49% diameter reduction; D 50-99% diameter reduction, and E total occlusion. Forty-eight patients had unilateral and 47 patients had bilateral bruits; 142 bruits were evaluated. The distribution of disease in the internal carotid artery was: A: 2% (3/142); B: 30% (42/142); C: 37% (53/142); D: 29% (41/142), and E: 2% (3/142). If the presence of a high grade stenosis of the internal carotid artery (50-99% diameter reduction) is an indication for invasive intervention, then 71% of these patients would not require contrast arteriography. The role of a direct ultrasonic study, such as Duplex scanning, in patients with asymptomatic bruits is discussed.

Auscultation↗
PubMed1982

Evaluation of carotid bifurcation disease: the role of common carotid artery velocity patterns.

We evaluated duplex ultrasonographic velocity patterns from the common carotid artery in 156 patients with arteriographically verified internal carotid artery disease. Flow to zero during diastole in the common carotid was found in three groups of patients: (1) those with flow to zero in both common carotids not related to disease of the carotid bulb; (2) those with a tight (90% to 99%) stenosis in the internal carotid; and (3) those with total occlusion of the internal carotid. Although such flow to zero is commonly observed with total occlusion of the internal carotid artery, it may also be seen with high-grade stenosis. Thus, when found, it is essential to ascertain if flow is indeed present in the internal carotid artery; understanding changes in velocity patterns of the common carotid has improved our overall accuracy in detecting extracranial carotid artery disease.

Arterial Occlusive Diseases↗
PubMed1982

Carotid artery stenosis following endarterectomy.

Duplex scanning and spectral analysis were used to detect carotid artery stenosis following 89 endarterectomies in 76 patients with a mean postoperative follow-up interval of 16 months. Operative arteriography was used in all cases to verify the technical result. Spectral changes indicating greater than 50%-diameter internal carotid stenosis were observed postoperatively in 32 of the 89 sides. Serial follow-up of 22 stenotic sides showed persistent stenosis in 12, regression of stenosis in nine, and internal carotid occlusion in one. The estimated overall incidence of persistent high-grade stenosis was 19%. Recurrent neurologic symptoms occurred in eight patients. This incidence of postoperative carotid stenosis is higher than estimates based on clinical criteria. The transient nature of some early postoperative stenosis is consistent with proliferation and regression of myointimal lesions in response to arterial injury.

Carotid Arteries↗
PubMed1982

A simple parameter for accurate detection of severe carotid disease.

The value of the ratio of the peak systolic velocity in the internal carotid artery to the end diastolic velocity in the common carotid artery in quantifying the severity of carotid arteriosclerosis has been investigated in 86 diseased vessels and 30 normal vessels. The ratio permitted gradation of disease into 60 per cent stenosis and greater with 95 per cent accuracy, 65 per cent stenosis and greater with 97 per cent accuracy and greater than 90 per cent stenosis with 100 per cent accuracy. The values for 30 normal sides studied fell below those of the 60 per cent stenosis group. The ratio has a value in predicting the severity of disease in the internal carotid artery in those with a 60 per cent stenosis and greater.

Blood Flow Velocity↗
PubMed1982

Pentoxifylline efficacy in the treatment of intermittent claudication: multicenter controlled double-blind trial with objective assessment of chronic occlusive arterial disease patients.

The efficacy, safety, and tolerance of pentoxifylline (Trental, Hoechst-Roussel Pharmaceuticals, Inc.) in the treatment of intermittent claudication associated with chronic occlusive arterial disease (COAD) were evaluated in a double-blind, placebo-controlled, parallel-group, multicenter clinical trial involving a total of 128 outpatients. The response to treatment was ascertained at regular intervals during the trial by measuring the distance walked prior to the onset of claudication when patients were subjected to a standardized treadmill test. Pentoxifylline given orally in doses up to 1200 mg/day was significantly more effective than placebo in increasing both the initial and absolute claudication distances in patients with COAD. Reduction of lower limb paresthesias also suggested greater clinical improvement in the pentoxifylline treated patients. These results support the hypothesis that pentoxifylline reduces blood viscosity by improving red cell flexibility, and thereby enhances blood flow in patients with COAD. White the precise mode of therapeutic action requires clarification, pentoxifylline was well tolerated with minimal unwanted effects.

Aged↗
PubMed1982

Computer based pattern recognition of carotid arterial disease using pulsed Doppler ultrasound.

A minicomputer based system has been developed for studying carotid artery blood flow data obtained for a combined B-mode, pulsed Doppler ultrasound scanner. The goals of this work are to devise and improve techniques for estimating the extent of atherosclerosis at the carotid artery bifurcation. Features are automatically extracted from spectrum analyzed Doppler blood flow data. Five statistical pattern recognition algorithms are compared, with cross validation being used to improve the estimate of classification accuracy. A data collection protocol has been devised in which four sites are studied along each carotid arterial system. Classification of unknowns is done using a hierarchy of three decisions.

Adult↗