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The use of graduated compression stockings in the prevention of postoperative deep vein thrombosis.

The efficacy of graduated compression stockings in the prevention of postoperative deep vein thrombosis was studied in a randomized, prospective, controlled trial of 200 patients, aged 40 years and over, undergoing abdominal surgery (100 for benign disease, 100 for malignant conditions). Deep vein thrombosis was diagnosed by the 125I-fibrinogen test. The incidence of deep vein thrombosis was 35.9 per cent in the control group (103 patients) and 15.5 per cent in the stockinged group (97 patients) (P less than 0.025). In the patients with benign disease, deep vein thrombosis developed in 24.5 per cent of the control limbs and 6.1 per cent of stockinged limbs (P less than 0.005); in patients with malignant disease the similar figures were 27.9 and 11.5 per cent (P less than 0.05). Increasing age did not alter the efficacy of the stockings. It is concluded that graduated compression stockings provide a safe and effective method of prophylaxis against deep vein thrombosis.

Abdomen↗

Pathology of the liver in Budd-Chiari syndrome: portal vein thrombosis and the histogenesis of veno-centric cirrhosis, veno-portal cirrhosis, and large regenerative nodules.

Hepatic vein (HV) thrombosis causes ascites, hepatomegaly, and severe congestion of the liver (Budd-Chiari syndrome [BCS]). Severe hepatic fibrosis develops in this syndrome with a variety of histological patterns. Some livers have a pattern of cirrhosis in which there is fibrous bridging between HVs and portal tracts (veno-portal cirrhosis). Other livers have a pattern of "reversed-lobulation cirrhosis" (veno-centric cirrhosis), in which fibrous bridging between HVs and portal tracts is minimal. The prevalence and pathogenesis of these forms of cirrhosis and the effect of portal vein (PV) thrombosis in this disease have not been studied. We examined 15 resected livers from patients with BCS to determine the distribution of vascular obstruction and the character of the parenchymal response. Six livers had veno-portal cirrhosis, and all of these had severe PV obliteration caused by thrombosis. Three livers had veno-centric cirrhosis and had normal medium and large PVs. The remaining six livers had mixed veno-centric/veno-portal cirrhosis and had moderate PV obliteration. The nodules in veno-centric cirrhosis had evidence of an unusual circulation with small arteries supplying a midzonal venous plexus that appeared to drain retrogradely into patent small PVs. Nine livers had large regenerative nodules histologically similar to focal nodular hyperplasia. PV thrombosis is a frequent occurrence in BCS. The correlation between PV thrombosis and the pattern of cirrhosis suggests a role for PV obliteration in the genesis of veno-portal bridging fibrosis in this disease and possibly in other diseases leading to cirrhosis.

Adult↗

Prophylaxis of postoperative venous thrombosis in a controlled trial comparing dextran 70 and low-dose heparin.

A controlled, randomized trial comparing dextran 70 and low-dose heparin with no treatment for prophylaxis of postoperative deep vein thrombosis is reported. A total of 168 patients who underwent general and urologic surgical operations participated in the trial. The 125I-fibrinogen test was used for diagnosis. The frequency of deep venous thrombosis was 27% in controls, 29% in patients who also received dextran 70, and 13% in patients treated with low-dose heparin. Only heparin therapy reduced the incidence of thrombosis. Epidural analgesia did not reduce the frequency of thrombosis. In patients with malilgnant diseases, the thrombotic process always extended proximally, at least to the knee. The highest frequency of thrombosis was seen after urologic surgery. Complications did not differ between the groups.

Aged↗

Hepatic infarction with portal thrombosis.

A case of hepatic infarction with portal thrombosis is reported. A 63-year-old woman with liver cirrhosis and esophageal varices was admitted for treatment of the esophageal varices. Endoscopic variceal ligation (EVL) and endoscopic injection sclerotherapy (EIS) were performed. Two months later, she experienced right hypochondralgia and right flank pain. Serum transaminase levels were suddenly elevated, and computed tomography scans of the liver showed multiple small nodular lesions. Her condition worsened, and she died of hepatic failure. Autopsy revealed splenic and portal vein thrombosis, multiple hepatic infarction, and evidence of chronic pancreatitis. We believe that liver cirrhosis and chronic pancreatitis were the main risk factors for the portal thrombosis, and the treatment for esophageal varices appeared to have triggered the thrombosis. The hepatic infarction was caused by the portal thrombosis.

Endoscopy, Digestive System↗

[Prognostic relevance of vena cava thrombosis in renal cell carcinoma].

The independent prognostic value of neoplastic extension of renal cell cancer (RCC) into the vena cava inferior has been the subject of several investigations reported to date. However, the use of vena cava thrombosis as an independent prognosticator of a patient's long-term survival is still debated. We have therefore correlated the clinical course of 53 patients with RCC and vena cava thrombosis with a control group consisting of 47 patients with renal cell tumors without vena cava thrombosis (follow-up: 1-154 months). The median long-term survival of patients with and without vena cava thrombosis was 32 and 35 months, respectively. Neither the propagation of the tumor into the vena cava (P = 0.391) nor the cranial extension of the thrombosis (P = 0.158)--even in case of propagation into the right atrium--could be identified as parameters of any prognostic value during univariate or multivariate statistical analysis.

Adult↗

Animal model of acute deep vein thrombosis.

PURPOSE: To develop an animal model of acute deep vein thrombosis (DVT). METHODS: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n = 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n = 3), or at 100 U/min (n = 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. RESULTS: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p = 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1. 32-1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0-1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. CONCLUSION: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution.

Animals↗

Prophylaxis of Venous Thrombosis.

Mechanical measures such as graduated compression stockings and intermittent compression boots are available for venous thrombosis prophylaxis, but compliance may be limited. Plantar venous pneumatic compression devices have attained widespread acceptance by both patients and nurses because of their comfort and compact size, but their track record for efficacy is poor. Inferior vena cava filters prevent pulmonary embolism, but do not halt the thrombotic process or prevent venous thrombosis. Pharmacologic prophylaxis traditionally has relied upon minidose unfractionated heparin; however, re-examination is warranted in the face of increasingly ill and complex patients. My opinion is that small, fixed doses of once-daily low molecular weight heparin will eventually replace minidose unfractionated heparin as the standard pharmacologic prophylaxis regimen for most surgical and medical patients. Prolongation of prophylaxis after hospital discharge should receive increased emphasis. Most patients being transferred to a skilled nursing facility should receive venous thromboembolism prophylaxis. Similarly, most patients undergoing total hip or knee replacement should receive prolonged preventive regimens, with at least 1 month of anticoagulation. Despite advances, certain aspects of venous thrombosis prophylaxis remain problematic. First, a surprisingly high number of hospitalized patients develop venous thrombosis because of failed (rather than omitted) prophylaxis. Second, many patients in intensive care have a combination of peripheral vascular disease and active bleeding (usually gastrointestinal) that precludes mechanical or pharmacologic prophylaxis. Third, neurosurgical patients undergoing craniotomy for brain tumors suffer a high rate of venous thrombosis and major pulmonary embolism despite the routine use of combined mechanical and pharmacologic prophylaxis. My opinion is that these three areas, in addition to the hospital culture of prophylaxis, should receive increased attention in an effort to prevent venous thromboembolism.

Journal Article↗

Cerebral Venous Thrombosis.

Cerebral venous thrombosis is a rare disorder with highly variable and nonspecific clinical presentations. For these reasons, specific treatment should be given only when the diagnosis has been firmly established. Etiologic diagnosis should begin in the emergency department to identify underlying conditions that require specific treatment. The mainstay of treatment is anticoagulation with heparin, even in the case of cerebral hemorrhage, followed as soon as possible by oral anticoagulant administration. The optimal duration of oral anticoagulation has not been established. By analogy with systemic venous thrombosis, it should be prolonged 3 to 6 months. When a high risk of recurrence is present, treatment should be continued until the risk disappears. In contrast to arterial stroke, complete recovery of prolonged or severe neurologic deficit is possible, justifying initiation of anticoagulation even when the clinical situation seems desperate. For the same reason, aggressive treatment of intracranial hypertension and seizures or status epilepticus is warranted. Screening for extraneurologic venous thrombosis should be done by means of clinical examination and, if necessary, specific imaging procedures. Local thrombolysis is not yet of proven efficacy and safety. It can be used in patients with clinical worsening related to documented extension of the venous thrombosis despite anticoagulation and in the absence of cerebral hematoma. Surgical treatment is limited to external ventricular drainage and suboccipital craniotomy in the very rare cases of cerebellar vein thrombosis with edematous cerebellar infarct.

Journal Article↗

Thrombosis of epicardial coronary veins in acute myocardial infarction.

Thrombosis of epicardial coronary veins was demonstrated in 16 of 50 cases of left ventricular acute myocardial infarction and/or recent coronary arterial thrombosis. All patients with valvular heart disease had venous thrombosis. In cases without valvular heart disease, venous thrombosis was seen in infarctions involving more than 30% of the left ventricular myocardial mass with a post-attack survival time of at least 24 hours. The veins thrombosed were in all cases those draining the infarcted myocardium. Coronary vein thrombosis seems not to be prevented by anticoagulant medication.

Acute Disease↗

Heparin therapy for deep venous thrombosis.

One hundred fifty-six cases of deep venous thrombosis were reviewed. A previous episode of thrombosis, seen in 47 percent of the patients, was the most common predisposing factor. Medical illness, operation and local trauma were other important predisposing factors. Treatment consisted of continuous intravenous heparin therapy monitored by the activated coagulation time of whole blood (ACT). Thirty-three patients with an average ACT greater than 180 seconds had a more rapid recovery and had no recurrent deep venous thrombosis, embolism or failure to improve. Recurrent thrombosis, embolism or failure to improve was seen in 7 of 65 patients with an average ACT below 180 seconds. Major bleeding, defined as life-threatening bleeding or bleeding requiring transfusion, was not increased when the ACT was over 180 seconds, although minor bleeding was increased. Bleeding was also increased in women, elderly and postoperative patients. We advocate the use of higher doses of heparin to treat most patients with deep venous thrombosis because of the more rapid and complete recovery.

Adolescent↗

Postoperative deep venous thrombosis in Japan. Incidence and prophylaxis.

The incidence of postoperative deep venous thrombosis was investigated using the iodine-125-fibrinogen method in 256 patients undergoing major surgery. Deep venous thrombosis was found in 49 patients (15.3 percent), and nonfatal pulmonary embolism developed in one of seven patients in whom the thrombus extended to the popliteal vein. The same investigation was performed in 110 patients who wore a graduated compression stocking on one leg, with the other leg serving as a control. Deep venous thrombosis was found in 4 of 110 stockinged legs (3.6 percent) and in 16 of 110 control legs (14.5 percent). The incidence of deep venous thrombosis decreased significantly in patients who wore the stocking. An increase in femoral venous flow velocity was found in the stockinged legs by the Doppler method. The mean velocity of venous return by xenon-133 clearance was significantly greater in the stockinged legs than in the control legs. These findings were considered to support the efficacy of graduated compression stockings for the prevention of deep venous thrombosis.

Adolescent↗

Massive venous thrombosis of the extremities.

Massive venous thromboses of the extremities, although uncommon, are responsible for many of the long-term sequelae associated with venous disease. The charts of all patients with a diagnosis of iliofemoral venous thrombosis or subclavian vein thrombosis over a 6-year period were reviewed. There were 59 patients with iliofemoral venous thrombosis and 18 patients with subclavian vein thrombosis. Iliofemoral venous thromboses were three times more common, showed the classic leftsided predominance, and were more likely to be idiopathic. Subclavian vein thromboses showed no side or sex predilection and were due to anatomic abnormalities, intravenous lines, or radiation. Iliofemoral venous thrombosis showed poor response to lytic therapy, whereas subclavian vein thromboses were effectively lysed in those patients in whom it could be used. Massive venous thromboses of the extremities, although similar in presentation, have different characteristics depending upon the extremity affected. The cause, frequency, and response to treatment differ, which could ultimately influence outcome and the severity of postphlebitic symptoms.

Arm↗

A comparison of impedance plethysmography and strain gauge plethysmography in the diagnosis of deep venous thrombosis in symptomatic outpatients.

Strain gauge plethysmography and impedance plethysmography are non-invasive diagnostic techniques for deep venous thrombosis. In 145 consecutive out-patients presented with suspected acute deep venous thrombosis we compared these two techniques. Venography was performed if one or both tests were positive. Both tests were repeatedly normal in 91 (63%) patients, while in 38 (26%) patients both tests were abnormal and venography confirmed the presence of venous thrombosis. In six other patients the impedance plethysmography test result and venography were positive while the result of the strain gauge plethysmography test was normal. This difference was statistically significant (p less than 0.001). Four of these six patients had acute proximal thrombosis of the deep leg veins. The impedance plethysmography was falsely positive in four patients while strain gauge plethysmography was falsely abnormal in one patient. We conclude that in the diagnostic management of patients with suspected deep venous thrombosis, impedance plethysmography is superior to strain gauge plethysmography.

Diagnostic Errors↗

Experimental thrombosis model induced by free radicals. Application to aspirin and other different substances.

A large number of experimental studies suggests that oxygen free radicals play a major role in the pathogenesis of the myocardial lesions observed during the sequence ischemia-reperfusion. The purpose of this study was to determine whether oxygen free radicals can induce thrombosis. In so doing we have developed a new experimental thrombosis model. Reproducible focal thrombosis has been achieved by irradiating mesenteric arterioles of rat for variable time with green filtered light issuing from a mercury lamp after systemic injection of different rose bengal doses. The number of emboli that remove in the blood (N), the duration of total occlusion (T) and the number of emboli per minute were then measured. As control, no rose bengal administration was done and the vessels were exposed to the filtered light. In comparison with this control, results clearly showed that free radicals always induced thrombosis and the induced thrombus was mainly composed of platelets. In this new thrombosis model induced by free radicals antithrombotic drugs (aspirin, 200 mg/Kg, heparin, 2 mg/Kg) and antioxidants (vitamin C, 10 and 20 mg/Kg, allopurinol, 200 and 300 mg/Kg, vitamin E, 500 and 1000 mg/Kg) have been tested. Results have shown that only heparin and vitamin E had an antithrombotic effect on thrombus formation induced by free radicals. This model should be useful in studying the effects of different drugs and could lead to new treatment modalities for ischemic accident and other cardiovascular diseases.

Allopurinol↗

Heparin therapy for venous thrombosis and pulmonary embolism.

Intravenous heparin is the initial treatment of choice for most patients with acute pulmonary embolism or proximal deep vein thrombosis. The primary objective of initial heparin therapy in such patients is to prevent recurrent venous thromboembolism. The efficacy of intravenous heparin for this purpose has been established by randomized clinical trials in patients with pulmonary embolism, and more recently, in patients with proximal vein thrombosis. Heparin is given as an initial intravenous bolus of 5000 units, followed by a maintenance dose of 30,000-40,000 units per 24 h by continuous intravenous infusion. A recent randomized trial in patients with proximal vein thrombosis indicates that failure to achieve an adequate anticoagulant response (APTT greater than 1.5 times control) is associated with a high risk (25%) of recurrent venous thromboembolism. Intravenous heparin administered in doses that prolong the activated partial thromboplastin time (APTT) to 1.5 or more times the control value is highly effective, and associated with a low frequency (2%) of recurrent venous thromboembolism. Heparin is continued for 7-10 days, overlapped with warfarin sodium during the last 4-5 days. Multiple randomized clinical trials indicate that this approach is highly effective. An alternative approach is to commence heparin and oral anticoagulants together at the time of diagnosis, and to discontinue heparin on the fourth or fifth day. A recent randomized trial in patients with submassive venous thrombosis or pulmonary embolism suggests that 4-5 days of initial heparin therapy is effective and safe, but this approach must be evaluated by further randomized trials before it is recommended for patients with extensive proximal vein thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Heparin↗

Duplex ultrasound diagnosis of symptomatic proximal deep vein thrombosis of lower limbs.

Real time ultrasound (US) was used to examine 165 consecutive inpatients with clinically suspected deep vein thrombosis of lower limbs. In order to evaluate accuracy, the results of non-invasive techniques were compared with ascending venography, performed in all patients. Assessment included only femoro-popliteal veins, because of difficulty in visualizing calf vein with US. Diagnosis of thrombosis was based on noncompressibility of the examined veins; pulsed Doppler provided further information by evaluating blood flow. In our series Duplex ultrasound was very accurate in detecting acute thrombosis of the proximal veins, sensitivity being 97% and specificity 98%. With US it is also possible to detect conditions that mimic deep vein thrombosis, such as muscular rupture, hematoma, popliteal cyst or compressive tumors. In conclusion US is considered a valid alternative to contrast venography in the diagnosis of proximal vein thrombosis of lower limbs.

Adolescent↗

Treatment of type II endoleaks with a novel polyurethane thrombogenic foam: induction of endoleak thrombosis and elimination of intra-aneurysmal pressure in the canine model.

OBJECTIVE: The clinical significance and treatment of retrograde collateral arterial perfusion of abdominal aortic aneurysms after endovascular repair (type II endoleak) have not been completely characterized. A canine abdominal aortic aneurysm model of type II endoleak with an implanted pressure transducer was used to evaluate the use of polyurethane foam to induce thrombosis of type II endoleaks. The effect on endoleak patency, intra-aneurysmal pressure, and thrombus histology was studied. METHODS: Prosthetic aneurysms with an intraluminal, solid-state, strain-gauge pressure transducer were created in the infrarenal aorta of 14 mongrel dogs. Aneurysm side-branch vessels were reimplanted into the prosthetic aneurysm of 10 animals by using a Carrel patch. Type II (retrograde) endoleaks were created by excluding the aneurysm from antegrade perfusion with an impermeable stent graft. Thrombosis of the type II endoleak was induced by implantation of polyurethane foam into the prosthetic aneurysm sac of four animals. Six animals with type II endoleaks were not treated. In four control animals, no collateral side branches were reimplanted, and therefore no endoleak was created. Intra-aneurysmal and systemic pressures were measured daily for 60 to 90 days after the implantation of the stent graft. Endoleak patency and flow were assessed during surgery and at the time of death by using angiographic imaging and duplex ultrasonography. Histologic analysis of the intra-aneurysmal thrombus was also performed. RESULTS: Intra-aneurysmal pressure values are indexed to systemic pressure and are represented as a percentage of the simultaneously obtained systemic pressure, which has a value of 1.0. All six animals with untreated type II endoleaks maintained patency of the endoleak and side-branch arteries throughout the study period. Compared with control aneurysms that had no endoleak, animals with patent type II endoleaks exhibited significantly higher intra-aneurysmal pressurization (systolic pressure: patent type II endoleak, 0.702 +/- 0.283; control, 0.172 +/- 0.091; P < .001; mean pressure: endoleak, 0.784 +/- 0.229; control, 0.137 +/- 0.102; P < .001; pulse pressure: endoleak, 0.406 +/- 0.248; control, 0.098 +/- 0.077; P < .001; P < .001 for comparison for all groups by analysis of variance). Treatment of the type II endoleak with polyurethane foam induced thrombosis of the endoleak and feeding side-branch arteries in all four animals with type II endoleaks. This resulted in intra-aneurysmal pressures statistically indistinguishable from the controls (systolic pressure, 0.183 +/- 0.08; mean pressure, 0.142 +/- 0.09; pulse pressure, 0.054 +/- 0.04; not significant). Angiography and histology documented persistent patency up to the time of death (mean, 64 days) for untreated type II endoleaks and confirmed thrombosis of polyurethane foam-treated endoleaks in all cases. CONCLUSIONS: Untreated type II endoleaks were associated with intra-aneurysmal pressures that were 70% to 80% of systemic pressure. Treatment with polyurethane foam resulted in a reduction of intra-aneurysmal pressure to a level that was indistinguishable from control aneurysms that had no endoleak. CLINICAL RELEVANCE: Endovascular repair of abdominal aortic aneurysms is dependent on the successful exclusion of the aneurysm from arterial circulation. Type II endoleaks originate from retrograde flow into the aneurysm sac. This study demonstrates the use of polyurethane foam to induce thrombosis in a canine model of a type II endoleak, thereby reducing intra-aneurysmal pressure to levels similar to levels in animals without endoleaks. This approach may be a strategy for future treatment of type II endoleaks.

Animals↗

Utility of leg ultrasonography in suspected symptomatic isolated calf deep venous thrombosis.

PURPOSE: To evaluate the utility of duplex ultrasonography in patients with suspected symptomatic, isolated calf deep venous thrombosis. PATIENTS AND METHODS: Thirty patients with clinically suspected isolated calf deep venous thrombosis were examined with both duplex ultrasonography and contrast venography and the results were compared. RESULTS: Venography detected 7 cases of isolated calf deep venous thrombosis, all of which were also detected by ultrasonography. Ultrasound identified an additional 3 cases of soleal vein thrombosis, but venography did not visualize these veins. Of the 20 negative ultrasound studies, 11 were technically inadequate; however, no false-negative ultrasound studies were noted. CONCLUSIONS: Compression ultrasonography may be reliable for the evaluation of patients with suspected symptomatic infrapopliteal deep venous thrombosis. Its apparent superiority to contrast venography in visualizing muscular calf veins warrants further study; however, the high rate of technical inadequacy in ultrasound studies observed here, if confirmed in larger studies, may limit the usefulness of ultrasound in this setting.

Adult↗