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Biomedical subjects

D S Sumner

Publications and source records attributed to D S Sumner.

At least 55 records · Page 3Linked to original sources

Contralateral internal carotid artery stenosis or occlusion: pitfall of correct ipsilateral classification--a study performed with color-flow imaging.

The records of 183 patients who had undergone color-flow imaging of the extracranial carotid arteries and subsequent bilateral cerebral arteriography were reviewed to determine whether contralateral carotid arterial disease adversely affects the accuracy of duplex scanning by increasing the velocity of flow in the ipsilateral artery. In 83 arteries the contralateral internal carotid artery had a diameter reduction greater than or equal to 80%; in the remaining 283, the contralateral artery was less severely diseased. Noninvasive findings correlated less well with arteriography in the group with contralateral disease (k = 0.69 +/- 0.06) than in the group with less severe contralateral stenosis (k = 0.78 +/- 0.03), and the incidence of false-positive errors was significantly (p = 0.02) higher (18% vs 7%). For all categories of ipsilateral stenosis, the mean peak systolic and end-diastolic velocities were elevated in the group with severe contralateral disease. This effect was most evident in the 50% to 79% diameter reduction category, especially in reference to the end-diastolic velocity (p = 0.2). However, the data correlating velocity with diameter reduction were widely scattered, indicating that the effect of contralateral disease is inconsistent. We conclude that severe disease of the contralateral carotid artery can lead to overreading ipsilateral disease and that velocity determinations should be interpreted cautiously under such circumstances.

Arterial Occlusive Diseases↗

Initial experience with color-flow duplex scanning of infrainguinal bypass grafts.

Seventy-eight infrainguinal grafts were evaluated by means of color-flow duplex imaging to demonstrate its utility in the routine surveillance of leg grafts as well as in the evaluation of grafts in which a problem is already suspected. Stenoses were identified in 15 (20%) of 76 grafts evaluated for screening purposes. Seven of these had confirmatory arteriograms, and five were revised. The remaining eight grafts with suspected stenoses were followed without angiography, and four (50%) subsequently failed. Only two (3.3%) of 61 grafts with normal scan outcomes have thrombosed. Fistulas were identified in 12 (37%) of 32 in situ grafts evaluated. Nine grafts with previously suspected problems based on decreased ankle-brachial indexes were scanned, and an explanation was found, confirmed by angiogram, and corrected in six. Detection of unsuspected stenoses in five grafts requiring revision and four grafts that later thrombosed without revision, as well as identification of fistulas in 37% of in situ grafts, confirms the importance of color-flow imaging as a screening tool.

Blood Flow Velocity↗

Ultrasonic screening for the detection of abdominal aortic aneurysms.

Detection of aortic aneurysms before they rupture is imperative if the mortality rate from this disease is to be reduced. Although large aneurysms frequently are palpable, small aneurysms--especially in obese patients--are seldom recognized on physical examination. Ultrasound, which is noninvasive, relatively inexpensive, and nearly 100 per cent accurate in identifying the presence or absence of aneurysms, is well suited to screening. In high-risk populations (patients over the age of 50 with coronary artery or peripheral vascular disease), ultrasonic screening is probably cost-effective.

Adult↗

Carotid stump syndrome: a colour-coded Doppler flow study.

Colour-coded Doppler flow imaging (angiodynography) was performed on 29 patients with 30 internal carotid artery occlusions. Large internal carotid stumps were revealed as intravascular cul-de-sacs demonstrating vortices of blue flow reversal. Large carotid stumps or significant external carotid stenoses were present in nine patients (9 arteries). Such patients were significantly more likely to develop symptoms of cerebral ischaemia during follow up which averaged 18 months (P = 0.016; Fisher exact). These results support the concept of embolisation from the carotid bifurcation (residual stump or external stenosis) as a cause of episodic cerebral ischaemia following internal carotid occlusion. Angiodynography may prove to be a useful tool for selecting appropriate patients for treatment.

Adult↗

Relationship of severity of lower limb peripheral vascular disease to mortality and morbidity: a six-year follow-up study.

Among the considerations affecting the therapeutic approach to patients with atherosclerosis of the lower extremities is their associated risk of death, myocardial infarction, stroke, and limb loss. To investigate the relationship of these events to the severity of peripheral vascular disease we undertook a 6-year review of 247 consecutive patients undergoing lower extremity noninvasive vascular assessment. There were 130 men and 117 women with a mean age of 65 +/- 15 years. Patients were categorized into four groups according to their ankle-brachial pressure indexes at their first visit. Ninety-seven patients had normal indexes (greater than or equal to 0.92), 86 had indexes of 0.50 to 0.91, 39 had indexes of 0.31 to 0.49, and 25 had indexes within the ischemic range, less than or equal to 0.30. At 6 years 64% of the patients with ischemic indexes were dead. This incidence was significantly higher than that of any other patient category (p less than 0.01). Diabetes also had a significantly adverse effect on survival. The incidence of stroke and myocardial infarction was similar for all disease groups. Thirteen percent and 32% of patients with indexes of 0.31 to 0.49 and less than or equal to 0.30, respectively, underwent limb amputation. We conclude that patients with evidence of mild to moderate peripheral vascular disease have a survival rate and risk of vascular-related disorders similar to those of patients of similar age with little evidence of disease, whereas an ankle-brachial pressure index less than or equal to 0.30 is associated with a malignant prognosis.

Adolescent↗

Noninvasive assessment of lower extremity arterial disease.

Although angiography is the accepted "gold standard" for demonstrating the presence of arterial occlusive disease, it is less accurate for grading the associated hemodynamic consequences and is prohibitively invasive and expensive to be used as a first-line investigation. Currently available noninvasive tests allow not only for the detection of perfusion abnormalities, but for an appreciation of their severity as well as their likely location. This information is invaluable for predicting the need for revascularization, guiding the choice of reconstructive procedure, and predicting the likelihood of healing of amputation wounds and ischemic lesions. Although some obstructive lesions are easily detected, others require more in-depth testing to reveal and quantify. Consequently, a thorough understanding of available noninvasive diagnostic modalities, including both their capabilities as well as their pitfalls, is paramount to the effective practice of vascular surgery.

Arterial Occlusive Diseases↗

Prevalence of asymptomatic carotid disease: results of duplex scanning in 348 unselected volunteers.

The risk of stroke in patients with asymptomatic carotid disease appears to be related to the presence of a high-grade stenosis. To determine the prevalence of such lesions, duplex scanning was performed on 348 unselected volunteers without symptoms who attended hospital-sponsored health fairs. There were 209 women and 139 men whose ages ranged from 24 to 91 years. Risk factors included hypertension (37%), diabetes (8%), and smoking (23%). One hundred seven subjects (31%) had evidence of extracranial carotid artery disease, 13 (4%) with greater than 50% stenosis, and three (1%) with greater than 80% stenosis of the internal carotid artery. Bilateral disease was present in 50 patients. Disease prevalence and severity were significantly correlated with age (p less than 0.001) and hypertension (p less than 0.01) but not with diabetes or smoking. The incidence of disease was similar in men and women. Although carotid plaques are common in people older than 50 years of age who do not have symptoms, the prevalence of high-grade stenosis--even in the elderly hypertension population--is low, casting doubt on the cost-effectiveness of generalized screening.

Adult↗

Buttock claudication from isolated bilateral internal iliac arterial stenoses.

An unusual case is reported of severe buttock claudication in a woman with normal ankle systolic pressures after exercise, for which the cause was eventually found to be isolated bilateral hypogastric arterial stenosis. Although a normal ankle pressure response to exercise usually rules out vascular obstruction in patients with symptoms suggestive of intermittent claudication, the diagnosis of isolated hypogastric arterial disease should be entertained when a neurogenic or orthopedic explanation can be excluded.

Adult↗

Relationship of venous reflux to the site of venous valvular incompetence: implications for venous reconstructive surgery.

To evaluate the relationship of the site of venous valvular incompetence to the severity of venous reflux, legs of 71 patients with suspected chronic venous insufficiency were evaluated with Doppler ultrasonography and photoplethysmography. A venous recovery time (VRT) of less than 20 seconds after calf muscle exercise was considered indicative of significant reflux. Average VRTs were brief in 15 legs with stasis changes (10 +/- 7 seconds), longer in 42 legs with edema (26 +/- 23 seconds), and normal in 64 asymptomatic legs (37 +/- 24 seconds) and 16 legs with pain (53 +/- 19 seconds). Average VRTs in limbs with incompetent saphenous veins were abnormal. In limbs with competent superficial veins, only those with incompetent distal deep veins (popliteal and posterior tibial) had abnormal VRTs (14 +/- 10 seconds). VRTs in limbs with no detectable valvular incompetence and in those with incompetence limited to the proximal deep veins (common and superficial femoral) were normal (47 +/- 23 and 42 +/- 27 seconds, respectively). When superficial veins were incompetent, an ankle tourniquet normalized VRTs in 63% of legs with proximal deep venous incompetence and in only 33% of legs with distal deep venous incompetence. It is concluded that venous reflux is largely determined by saphenous and distal deep valvular function and that competence of the proximal valves has little effect. Decreased venous reflux would not be expected after proximal valvular reconstruction.

Female↗

Prevalence of extracranial carotid artery disease: a survey of an asymptomatic population with noninvasive techniques.

To investigate the prevalence of internal carotid arterial stenosis in an unselected asymptomatic population over 50 years of age, 102 volunteers from one church congregation were studied with ultrasonic arteriography, spectral analysis, and ocular pneumoplethysmography. Fifty subjects were 50 to 59 years old; 33 were 60 to 69 years of age; and 19 were older than 70 years. Forty-five were men and 57 were women. Risk factors included diabetes mellitus (4%), heart disease (9%), hypertension (24%), peripheral vascular disease (20%), and smoking (46%). Disease was found in 11 subjects (10.8%). Of the 204 internal carotid arteries, 13 (6.4%) were abnormal. Two vessels had 20% diameter stenosis; four had stenoses of 20% to 39%; five had stenoses of 40% to 59%; one had a stenosis of 60% to 79%; and one was occluded. Stenoses greater than 40% occurred in 4% of the 50 to 59 years of age group, 6% of the 60 to 69 years of age group, and 11% of the greater than 70 years of age group. Although the prevalence of carotid stenosis was increased in all subjects who had risk factors, only the association with heart disease reached statistical significance. These results indicate that carotid stenosis is present in an appreciable number of asymptomatic subjects over the age of 50 years and suggest that its prevalence is associated with age and other risk factors.

Age Factors↗

Chylous ascites after abdominal aortic aneurysmectomy: successful management with a peritoneovenous shunt.

Postoperative chylous ascites is a rare complication of aortic aneurysmectomy. Although increasing numbers of abdominal aortic aneurysms are being resected annually, there have been only eight previously reported cases of chylous ascites after this operation. This article describes the ninth case of postoperative chylous ascites after abdominal aortic aneurysm resection and emphasizes the value of management with peritoneovenous shunting.

Aged↗

Distribution of venous valvular incompetence in patients with the postphlebitic syndrome.

The records of 122 patients who underwent Doppler evaluation for the postphlebitic syndrome were reviewed to determine the relationship between location of venous valvular incompetence and severity of clinical signs. Categorized according to the most severe physical finding, there were 35 limbs with perimalleolar ulcers, 113 with stasis pigmentation, 26 with swelling, and 70 with no overt signs. Incompetent veins, either deep or superficial, were present in 93% of the symptomatic and 59% of the asymptomatic limbs. Proximal (iliofemoral) deep venous incompetence was not strongly correlated with disease severity (p less than 0.10), but distal (popliteotibial) deep venous and superficial venous incompetence were (both, p less than 0.0005). The relative frequency of isolated proximal incompetence appeared to diminish with increasing disease severity; whereas that of distal incompetence, with or without associated proximal venous incompetence, increased. Isolated proximal venous incompetence was found in only 5% of limbs with severe disease (ulcers or pigmentation). In limbs with severe signs, distal venous incompetence was present in 67% of those with proximal venous incompetence and in 57% of those in which the proximal valves were competent. These findings cast doubt on the potential value of proximal venous valvular reconstruction, especially in limbs with combined proximal and distal insufficiency.

Adolescent↗

Relative accuracy of the diagnostic components of noninvasive carotid arterial tests: a comparison of pulsed Doppler arteriography and spectrum analysis.

Pulsed Doppler ultrasonography (UA), sound spectrum analysis, and subjective interpretation of the audible signal are valuable methods for assessing carotid arterial disease; however, the relative contribution of each in making a diagnosis is disputed. To investigate this issue, 258 noninvasive carotid studies with measured x-ray comparisons were reviewed. Internal carotid spectra, UA images, and images combined with the technician's comments were each interpreted blindly by three independent readers. Percentage of stenosis was categorized into six groups: 0, 1% to 24%, 25% to 49%, 50% to 74%, 75% to 99%, and 100%. Each reader's assessment of the individual noninvasive components and his overall reading of the complete study were compared with x-ray findings and with those of the other two readers. The readings of the three observers were consistent within each diagnostic component (p less than 0.001). For each reader, the technician's comments significantly improved the accuracy of ultrasonic imaging alone (p less than 0.001). Spectrum analysis was as good as the image plus technician's comments and, for two of three readers, was better than the image alone (p less than 0.001).

Angiography↗

Physiology of the peaked finger pulse in normal and cold-sensitive subjects.

A unique peaked digital pulse contour (DPC) is frequently observed in patients with cold sensitivity, but the pathophysiology of this pulse remains obscure. To investigate the responses of the DPC to cold exposure, finger blood pressure (FBP), finger blood flow (FBF), and finger skin temperature (FST) were measured in fingers of both hands of 13 normal subjects and in 16 patients with cold sensitivity. The ratio, FBP/FBF, was used to estimate small vessel resistance (SVR). One hand was immersed sequentially in water at 40 degrees, 30 degrees, 20 degrees, and 10 degrees C, while the other hand remained in room air. DPCs were classified as normal (N), intermediate (I), intermediate-peaked (IP), peaked (P), obstructive (O), and spastic obstructive (SO). At room temperature, fingers with I, IP, O, and SO pulses had increased SVRs and decreased FSTs, and those with O and SO had decreased FBP. On cold exposure IP pulses appeared in both hands of both normal and cold-sensitive subjects, but P pulses developed only on the cooled side. IP and P pulses were associated with an increase in SVR. We concluded that IP pulses are related to reflex sympathetic arteriolar vasoconstriction, that P pulses imply vasoconstriction produced directly by cold exposure, and that O, SO, or absent pulses are indicative of digital arterial vasospasm.

Adolescent↗

Noninvasive assessment of upper extremity and hand ischemia.

The diagnosis and follow-up of patients with ischemic problems of the arm and hand is facilitated by the selective use of simple noninvasive methods readily available in most vascular laboratories. These tests help differentiate between obstruction and vasospasm and document the severity of the circulatory impairment. Although they may not establish etiology, they often clarify the need for further laboratory tests or arteriography.

Arm↗

Neonatal thoracoabdominal aortic thrombosis associated with the umbilical artery catheter: successful management by transaortic thrombectomy.

The case of a newborn infant who underwent a successful aortoiliac thrombectomy for thoracoabdominal aortic thrombosis induced by an umbilical artery catheter is presented. The case is notable both for the extent of the thrombotic process and the renal and cardiac failure noted initially. Only eight other attempts at neonatal aortic thrombectomy associated with umbilical artery catheters have been reported in the English language literature. Our experience, in addition to that in the literature, suggests that aggressive treatment should be considered in neonates with this severe complication.

Aorta, Abdominal↗