This study investigated changes in the deep venous system and the development of the postthrombotic syndrome (PTS) after an episode of acute deep vein thrombosis (DVT). Methods: Seventy-eight patients (41 male patients, 37 female patients) with acute DVT in 83 legs (31 right, 42 left, five bilateral) underwent annual follow-up examinations for 1 to 6 years (median, 3 years) for symptoms and signs of the PTS. A venous duplex scan was performed at each visit to detect obstruction and reflux in the veins, both of which may contribute to the development of the PTS. DVT was primal, in 69 limbs and recurrent in 14 limbs. Results: When last examined 49 limbs were free of symptoms, and 34 had the PTS (23 edema only, 11 hyperpigmentation). Only two patients had ulcers during the follow-up period; both patients had the ulcers in areas of hyperpigmentation in limbs with recurrent DVT. The extent of disease was similar in limbs with the PTS (79% multisegment, 18% single segment) and those without the PTS (69% multisegment, 12% single segment). In limbs with the PTS the deep veins were normal in only one (3%), six (18%) showed reflux only, five (15%) obstruction only, and 22 had features of both obstruction and reflux (65%). In limbs without the PTS the deep veins showed no abnormality in nine (18%), reflux only in 17 (35%), obstruction only in six (12%), and reflux with obstruction in 17 (35%). In the 11 limbs with hyperpigmentation nine had obstruction and reflux noted, one had obstruction only, and one had reflux alone. Conclusions: After an episode of acute DVT 12% of the limbs returned to normal by duplex criteria. Although only 13% developed skin complications, 41% had features of the PTS. Limbs with the PTS had more than three times the odds of having combined reflux and obstruction than did limbs without the PTS (odds ratio -3.5, 0.95 confidence intervals = 1.4, 8.6). Continued study of these patients will determine the course of those limbs with venous abnormalities that have not yet developed symptoms and signs of the PTS.

Background-The aim of this study was to determine the incidence of and the risk factors associated with progression of renal artery disease in individuals with atherosclerotic renal artery stenosis (ARAS). Methods and Results-Subjects with Ն1 ARAS were monitored with serial renal artery duplex scans. A total of 295 kidneys in 170 patients were monitored for a mean of 33 months. Overall, the cumulative incidence of ARAS progression was 35% at 3 years and 51% at 5 years. The 3-year cumulative incidence of renal artery disease progression stratified by baseline disease classification was 18%, 28%, and 49% for renal arteries initially classified as normal, Ͻ60% stenosis, and Ն60% stenosis, respectively (Pϭ0.03, log-rank test). There were only 9 renal artery occlusions during the study, all of which occurred in renal arteries having Ն60% stenosis at the examination before the detection of occlusion. A stepwise Cox proportional hazards model included 4 baseline factors that were significantly associated with the risk of renal artery disease progression during follow-up: systolic blood pressure Ն160 mm Hg (relative risk [RR]ϭ2.1; 95% CI, 1.2 to 3.5), diabetes mellitus (RRϭ2.0; 95% CI, 1.2 to 3.3), and high-grade (Ͼ60% stenosis or occlusion) disease in either the ipsilateral (RRϭ1.9; 95% CI, 1.2 to 3.0) or contralateral (RRϭ1.7; 95% CI, 1.0 to 2.8) renal artery. Conclusions-Although renal artery disease progression is a frequent occurrence, progression to total renal artery occlusion is not. The risk of renal artery disease progression is highest among individuals with preexisting high-grade stenosis in either renal artery, elevated systolic blood pressure, and diabetes mellitus. (Circulation. 1998;98:2866-2872.)

Early recanalization is important in preserving valve integrity for all but the posterior tibial segment. However, the small number of patients with reflux despite early lysis (< 1 month) or without reflux despite relatively late lysis (> 9 to 12 months) suggests that other factors may also contribute to the development of valvular incompetence. These factors may be particularly important in the posterior tibial vein, in which lysis time has little relationship to the ultimate development of reflux.

Purpose: Although the prevalence of renal artery stenosis in patients with peripheral arterial disease is in the range of 30% to 40%, the role of renal revascularization in patients without severe hypertension or kidney failure is controversial. Duplex scanning is a noninvasive technique that is ideally suited for screening and follow-up of renal artery disease. The purpose of this study was to document the natural history of renal artery stenosis in patients who were not candidates for immediate renal revascularization. Methods: Eighty-four patients with at least one abnormal renal artery detected by duplex scanning were recruited from patients being screened for renal artery stenosis. Of the 168 renal artery/kidney sides, 29 were excluded (15 prior interventions, 6 nondiagnostic duplex scans, 8 presumed nonatherosclerotic lesions), leaving 80 patients with 139 sides for the follow-up protocol. Renal arteries were classified as normal, less than 60% stenosis, 60% or greater stenosis, or occluded by use of previously validated criteria.Results: The study group included 36 men and 44 women with a mean age of 66 years who were monitored for a mean interval of 12.7 months. The initial status of the 139 renal arteries was normal in 36, less than 60% stenosis in 35, 60% or greater stenosis in 63, and occluded in 5. Although none of the initially normal renal arteries showed disease progression, the cumulative incidence of progression from less than 60% to 60% or greater renal artery stenosis was 23% ± 9% at 1 year and 42% ± 14% at 2 years. All four renal arteries that progressed to occlusion had 60% or greater stenoses at the initial visit, and for those sides with a 60% or greater stenosis, the cumulative incidence of progression to occlusion was 5% ± 3% at 1 year and 11% ± 6% at 2 years. The mean decrease in kidney length associated with progression of renal artery stenosis to occlusion was 1.8 cm. Conclusions: Progression of renal artery stenosis, as defined in this study, occurs at a rate of approximately 20% per year. Progression to occlusion is associated with a marked decrease in kidney length. Whether this natural history can be improved by earlier intervention for renal artery stenosis remains to be determined.