R ecognizing the considerable excess burden of both cerebrovascular disease and LEAD suffered by individuals with IDDM or NIDDM (1,2), a workshop was convened to 1) provide a current review of the knowledge pertaining to the prevalence, incidence, and risk factor associations of cerebrovascular disease and PVD in diabetes, and 2) review and make recommendations about the methodology for identifying and quantifying LEAD in both clinical and research settings.The workshop focused on the specific problems of measurement of PVD in diabetes and the need for a standard approach to ensure appropriate care and facilitate comparability of research findings across studies and over time. Recommendations for the measurement of LEAD in a primary-care setting and for epidemiological studies were developed, along with recommendations for more detailed assessment after referral to a vascular clinic. Specific recommendations for the assessment of cerebrovascular disease were not addressed.

A high resolution MR imaging technique using a custom designed flexible phased-array surface coil was developed to examine the wall of the carotid artery bifurcation in vivo. The phased-array consisted of two overlapping coils which increased the image signal-to-noise ratio at the depth of the carotid artery by approximately 70%, relative to a similarly sized single loop coil. The imaging protocol included a 2D T1-weighted (T1W) spin-echo scan and cardiac gated T2-weighted and proton density-weighted (PDW) fast spin-echo (FSE) scans. Images were obtained of six healthy volunteers and of one patient with known atherosclerotic disease several days before carotid endarterectomy. On T1W and PDW images of the healthy volunteers, the carotid arterial wall appeared to be comprised of two concentric rings; a high signal inner ring and a lower signal outer ring. The MR images of the patient revealed a calcified carotid bifurcation plaque which was confirmed during surgery. The endarterectomy specimen was imaged in vitro with MR and then sectioned histologically for correlation with the patients in vivo images. Our preliminary findings indicate that a high resolution technique may provide a noninvasive technique to study atherosclerosis of the carotid bifurcation.

A prospective study of 135 controls, 286 non-insulin-dependent diabetic patients, and 31 subjects with an elevated fasting plasma glucose was performed to assess the prevalence of high-grade carotid artery stenosis. The carotid artery evaluation was performed using an ultrasonic duplex scanner. When those patients with an elevated fasting plasma glucose and non-insulin-dependent diabetes were considered together, the prevalence was 8.2% as compared with 0.7% for the controls (P = 0.0007). Those risk factors found to be significantly related to the higher prevalence of carotid disease in the combined groups of patients included age, ratio of systolic blood pressure to diastolic blood pressure, plasma cholesterol, and cigarette smoking. These findings may be an explanation for the greater incidence of stroke in patients with diabetes mellitus.

Only 15 (7%) of 209 patients with DVT exhibited no contraindications for thrombolytic treatment. Only a small fraction of patients with venous thrombosis will be potential candidates for this therapy.

Pathological alterations in blood flow develop in response to a wide variety of diseases which affect both the macro-and microcirculation. To attempt to cover all aspects of this problem is simply not possible in a brief review. For this reason I will confine my comments to those flow abnor malities that occur secondary to atherosclerosis which involves the large and medium sized arteries of the lower extremities. Material for a review of this type can be found in two different types of reports. The first deals almost exclusively with the results of clinical experience and are usually intended to document the results of treatment. The second type of communication deals with investigative studies that have been undertaken to clarify or answer some of the current unknown aspects of a particular problem.I will concentrate on the clinical research activities that I roughly define as those efforts which extend beyond using the patient's history, physical examination, and patient testimony as the sole criteria of the functional disability that occurs and the results of therapy. While it has often been stated that physiologic measurements in peripheral arterial disease are of in terest only, it is becoming increasingly apparent that more objective methods of study will have to be applied to the human if we are to gain a more meaning ful understanding of cardiovascular disease. Although animal studies are helpful in perfecting and evaluating study methods, investigators have all too often attempted to apply the data to the human. We have not yet found a suitable analogue for human physiology, much less for human athero sclerosis. I t is now well known that the cardiovascular system of an anesthe tized animal bears little resemblance even to the awake animal. Further developments in instrumentation will permit the clinical researcher of the future to obtain data safely from the human. Then and only then will we find answers to many of our unsolved problems in the area of atherosclerosis and its effect on different vascular beds.We now know that atherosclerosis tends to involve particular segments of the arterial system which are in close relation to branch points, bifur cations, and areas where vessels follow a tortuous course. The process itself tends to involve the intima in its earliest stages but later the entire wall may become distorted by the process (1). Because the disease involves all coats of the arterial wall, it influences not only the pressure-flow characteristics of the system but its visco-elastic properties as well. Ideally, we would like to measure not only pressure and flow but obtain data on the changes in 1 Annu. Rev. Med. 1969.20:1-14. Downloaded from www.annualreviews.org Access provided by University of California -Davis on 02/09/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS