Showing papers by "Thomas W. Wakefield published in 2002"

Variation in death rate after abdominal aortic aneurysmectomy in the United States: impact of hospital volume, gender, and age.

Abstract: Each year in the United States, many patients are in need of elective or emergent repair of abdominal aortic aneurysms (AAAs). Health policy initiatives to reduce surgical death rates are therefore an important public health issue. 1,2 Recently, there has been increased interest in regionalization of high-risk surgical procedures, such as aortic aneurysmectomy, to high-volume hospitals (HVHs) in an effort to reduce the number of perioperative deaths. Hospital volume has clearly been shown to be associated with improved outcomes for several complex vascular surgical procedures, including AAA repair. 3–5 Several population-based studies using state discharge data have consistently shown lower surgical death rates at HVHs. 6–12 However, the validity of studies conducted at the state level is questionable because there are often only a few HVHs in each state, and the effect of volume on outcome may be overestimated if a single HVH “overperforms” relative to other HVHs. 13 Conversely, the effect may be underestimated if certain low-volume hospitals (LVHs) “overperform” compared with their LVH colleagues. Obtaining a precise estimate for the magnitude of the “volume–outcome effect” of each high-risk surgical procedure is extremely important from a health policy perspective. The stronger the association between volume and the death rate, the more incentive exists for regionalization of patients to HVHs. The current study was performed using a database representative of the entire United States to gain a precise and generalizable estimate of the effect of hospital volume on the in-hospital death rate after repair of intact and ruptured AAAs.

Triplex ultrasound: elasticity imaging to age deep venous thrombosis

Abstract: Deep venous thrombosis (DVT), and its sequela, pulmonary embolism (PE), is the leading cause of preventable in-hospital mortality in the USA and other developed countries. After it is detected, acute clots must be differentiated from chronic DVT for appropriate treatment. However, there are no reliable thrombus staging methods presently available in clinical practice. In this study, we tested the hypothesis that blood clots can be detected and staged using a triplex ultrasound (US) test. Triplex US is based on a "gold standard" duplex US technique augmented by US-based reconstructive elasticity imaging. Fibrin-composed blood clots harden with development and organization. By imaging clot elasticity, it may be possible to both detect and differentiate clots and, therefore, provide an urgently needed noninvasive means of DVT staging.

New and effective treatment of experimentally induced venous thrombosis with anti-inflammatory rPSGL-Ig.

Abstract: Background: P-selectin antagonism decreases thrombosis and inflammation in animal models of venous thrombosis (VT) prophylaxis. This study defines results using a P-selectin receptor antagonist for VT treatment. Methods: Eight juvenile baboons underwent 6 h of iliofemoral venous stasis to produce an occlusive VT. Two days later, animals were treated for 14 days with rPSGL-Ig, 4 mg/kg (n3), LMWH (n2) or saline (n3) and treatment continued weekly (rPSGL-Ig) or daily (LMWH, saline). The animals were examined and sacrificed 14 days after treatment initiation (n4) or on day 90 (n4). Results: Percent spontaneous vein reopening revealed a significant increase (p <0.05) in the proximal iliac vein in rPSGL-Ig and LMWH animals compared to controls (62%, 70% vs 8%), without differences in inflammation. No anticoagulation, thrombocytopenia, or wound complications were found in rPSGL-Ig animals. At 90 days, recanalization with iliac vein valve competence was found in treated animals. Conclusions: rPSGLIg successfully treated established VT without anticoagulation.

Compression stockings and venous function.

Abstract: Hypothesis Surgical compression stockings measurably improve venous physiologic mechanisms, and stocking brands do not differ from one another. Methods Eleven patients, (8 men and 3 women [mean age, 53 years]), were included. Six patients had primary venous insufficiency and 5 patients had secondary venous insufficiency; 5 patients were in CEAP class 4 and 6 were in CEAP class 5. Patients were randomly assigned to a sequence of 4 brands of knee-high, open-toe, 30– to 40–mm Hg stockings. Each patient wore a stocking for a 1-month equilibration period, then a different stocking monthly for 4 months in a row. Air plethysmography examinations were performed with and without stockings before and after each month of wear. Patients filled out a daily stocking record log and a monthly satisfaction survey. Stockings underwent compression testing after use. Results Stockings controlled reflux better than they improved calf muscle pump function. With stockings on, patients in CEAP 4 benefited more than those in CEAP 5 in decreasing reflux, while patients in CEAP 5 benefited more than those in CEAP 4 in improving calf muscle pump function. Changes in residual volume fraction were improved in patients in CEAP 5 wearing stockings but not in patients in CEAP 4. Patients with primary disease had greater volumes of reflux and calf ejection than with secondary disease. There were no hemodynamic differences between stocking brands but there were differences in patient compliance and acceptance. Conclusions Surgical support stockings seem to be more effective in controlling reflux than in improving calf muscle pump function. All stocking brands function equally as measured by air plethysmography.