Treatment of deep venous thrombosis and pulmonary embolism. Current recommendations

Recombinant streptokinase suppositories in the treatment of acute haemorrhoidal disease. Multicentre randomized double-blind placebo-controlled trial (THERESA-2)

AIM

A four-arm multicentre randomized double-blind placebo-controlled trial was undertaken to assess the effect and safety of suppositories containing recombinant streptokinase (rSK) at two dose levels (100,000 IU and 200,000 IU) with sodium salicylate (SS) compared with placebo and SS for the treatment of acute haemorrhoidal disease.

METHOD

Patients with acute symptoms of haemorrhoids were randomized to four treatment groups: (I) placebo, (II) SS, (III) SS + rSK 100,000 IU and (IV) SS + rSK 200,000 IU per suppository. Inpatient treatment was by four suppositories given every 6 h to discharge at 24 h. Evaluations were made at the time of discharge (24 h) and at 3, 5 and 20 days later. The main end-point was the degree of relief of pain, oedema and reduction in the size of the lesion by 90% on day 5. Adverse events and the occurrence of anti-SK antibodies were also determined.

RESULTS

Eighty patients were included. Respective response rates in the four groups were 16%, 30%, 25% and 52%. In the last group there was a significant difference (36.8%) compared with control (95% CI 7.0-58.4%). The time to response was significantly shorter (median 5 days) in the 200,000 IU rSK group with respect to the others. There were no adverse events attributable to the treatment. No increase in anti-SK antibodies was detected 20 days after treatment.

CONCLUSION

Suppositories with 200,000 IU rSK showed a significant improvement in symptoms of acute haemorrhoids, with an adequate safety profile.

Controversies and unresolved issues in antiphospholipid syndrome pathogenesis and management

While much is understood concerning the clinical features of patients with antiphospholipid syndrome (APS), many issues remain. The proper designation of patients with "definite" APS and the correct categorization of patients by both laboratory and clinical features are matters of ongoing debate. Recent proposals have identified new subsets of patients who have many typical features of APS but either do not fit the criteria for a "definite" diagnosis or have initially negative laboratory tests for antiphospholipid antibodies. Meanwhile, decisions about laboratory tests are based on expert opinion, rather than the results of controlled trials. As for treatment, many guidelines are offered, but few are backed by data from strong clinical trials. This article summarizes the clinical questions remaining to be answered and debates concerning pathogenesis, diagnosis, and management.

Thromboembolic Disorders in Cancer

Complex factors, including substances in cancer cells, cancer treatment effects, and venous stasis associated with chronic illness, blood vessel wall injury, and immobility, interact to place patients with cancer at risk for thrombosis. This article describes the etiology, clinical manifestations, diagnostic tests, and treatments for venous and pulmonary emboli associated with cancer. It explores the nurse's role in assessing patients who are at risk, managing symptomatic thrombosis and primary and secondary prevention of emboli, and administering anticoagulant therapy. As growing numbers of patients are treated in outpatient settings, oncology nurses play a critical role in the coordination of care for patients at risk for thrombosis. A nursing care plan summarizes key nursing strategies for assessment and intervention.

Thromboprophylaxis and thrombosis in medical, surgical, trauma, and obstetric/gynecologic patients

The International Consensus and the ACCP Sixth Consensus had a great impact on the clinical acceptance of LMWHs. These recommendations have been instrumental in initiating further clinical trial to answer key questions regarding thromboprophylaxis and in setting a new standard for patient care. Also, the key to cost containment in management of DVT/PE is to (1) define the etiology (blood coagulation protein or platelet defect), institute appropriate long-term therapy as indicated, and assess appropriate family members as indicated if a hereditary defect is found and (2) use LMWH as inpatient management. saving a minimum of 210,000.00 dollars per 1000 patients simply from cost savings of recurrence, saving 17 lives per 1000 patients, and saving exorbitant costs of care for patients with recurrence and development of chronic venous insufficiency. The use of outpatient LMWH will save 4,900,000.00 dollars per 1000 patients if applied to the 70% of patients with DVT who fit the criteria of no comorbid condition requiring hospitalization and who arrive early enough to allow a diagnosis to be sent home or hospitalized for 24 hours or less. The simple defining of defects leading to unexplained thrombosis will add another 3,000,000.00 dollars in savings per 1000 patients with DVT and approximately 350,000.00 dollars per 100 patients with thrombotic stroke. In those with transient ischemic attacks, defining the defect and instituting appropriate antithrombotic therapy, thereby potentially saving approximately 30% from developing a thrombotic stroke, amounts to approximately 350,500.00 dollars (= 30% of 1,168,500.00 dollars) in savings per 100 patients.

In vitro effectiveness of mechanical thrombectomy devices for large vessel diameter and low-pressure fluid dynamic applications

PURPOSE

To determine in vitro the efficacy of clot removal of the AngioJet (AJ; new 6-F generation), Hydrolyser (HL; 6-F), and Oasis (OS; 6-F) hydrodynamic thrombectomy devices and the Amplatz Thrombectomy Device fragmentation catheter (ATD; 8-F and new-generation 7-F) in large-diameter vessels and low-pressure fluid dynamic applications (ie, pulmonary embolism).

MATERIALS AND METHODS

Thrombectomy of clots (N = 60; n = 12 for each tested device) created from 5-day-old porcine blood (16 g) was performed with the AJ (with coaxial 0.035-inch guide wire), HL, OS, and ATD in a bench-top model simulating low-pressure fluid dynamics (pulsed flow, 1,250 L/min). Tubes made of silicone (20-mm inner diameter) containing thrombus simulated a large-diameter vessel. The effluent was passed through a three-step filter system (10-1,000 micro m; pressure drop, 15 mm Hg).

RESULTS

Mean thrombectomy time ranged from 83 seconds (7-F ATD) to 185 seconds (OS; P <.0001 compared to all). Remaining thrombus ranged from 5.4 g/32.7% (AJ) to 11.1 g/68.1% (HL; P <.001 compared to all). The AJ's fluid balance was 0.92, whereas the mean ratio of applied saline solution to aspirated fluid for the other devices were significantly different than isovolumetric conditions (HL, 0.64; OS, 0.59; P <.0001 compared to AJ). The AJ (0.36%), HL (0.43%), and OS (0.38%) caused the least overall emboli larger than 10 micro m; the ATD (7-F, 0.82%; 8-F, 0.74%) caused the most (P <.001 for both).

CONCLUSIONS

The tested mechanical thrombectomy devices showed performance differences in thrombectomy time, efficacy of thrombus removal, and peripheral embolization rates. Based on low embolization rates for all devices tested, the experimental data indicate that the 7-F ATD and the 0.035-inch guide-wire-compatible AJ showed feasibility advantages for thrombectomy in large vessel diameter and low-pressure fluid dynamic applications.

Variation in medical resource utilisation in the management of pulmonary embolism in Belgium

The objective of this study was to investigate, through a patient chart analysis, the average and the variation in the medical resource use in pulmonary embolism (PE) patients in Belgium, and to find explanatory variables for the possible variation. A sample of patients with confirmed PE (n = 54) from 5 centres was selected. The centres were representative for size and region. The charts were selected at random after applying a set of exclusion criteria, in order to avoid heterogeneity of the sample characteristics. Charts were analysed using a standardised case report form, and medical resource use was collected by an independent researcher. Only medical resources related to the PE were included. On average, it appeared that the management of PE was fairly consistent between the different centres. The total average cost of PE was [symbol: see text] 3394 (St. Err. = [symbol: see text] 323). Nevertheless, large differences were found in the number of diagnostic and follow-up tests. Also, a wide variation in duration of hospital stay was found (average = 14.6, p75-p25 = 9.0), but this effect was not explained by the type of centre nor the region. The two factors that explain duration of hospital stay are the number of days of IV heparin use and the intensity of diagnostic follow-up, as expressed by the number of VQ-scans.

Estudo experimental comparativo da eficácia antitrombótica da heparina convencional e da heparina de baixo peso molecular

Em estudo randomizado e cego comparou-se a eficácia antitrombótica (redução do peso do trombo) de duas heparinas; uma de baixo peso molecular (HBPM) e outra não fracionada - heparina convencional (HC). Foram utilizados dois procedimentos de trombose venosa experimental: no grupo I a trombose venosa foi induzida injetando-se oleato de etanolamina na veia jugular de 30 coelhos e glicose a 50% em mais 30, todos da raça New Zealand. No Grupo II a trombose venosa foi induzida por estase mediante a ligadura da veia cava de 30 ratos da raça Wistar. Não se encontrou diferenças estatisticamente significantes com relação à redução do peso do trombo em ambos os grupos. Também concluiu-se que a eficácia antitrombótica das drogas estudadas não variou conforme o tipo de estímulo indutor da trombose nos modelos testados, e que o oleato de etanolamina induziu de forma mais significante a formação de trombos no grupo I.

Interventional therapy for pulmonary embolism

Venous thromboembolism is a common cause of death. Acute massive pulmonary embolism (PE) is life-threatening and may require vigorous more invasive treatment. Several risk factors are related to increased incidence of massive PE. Anticoagulation is the most traditional treatment for PE but may not suffice in cases of massive PE. Systemic thrombolytic therapy, catheter-directed thrombolysis, percutaneous embolectomy, and more recently, percutaneous thrombus fragmentation techniques with a multitude of devices are now available to treat the most severe cases of massive PE. Successful treatment of PE includes implementation of a treatment protocol and the use of associated techniques and devices.

Proficient and cost-effective approaches for the prevention and treatment of venous thrombosis and thromboembolism

Thrombosis is clearly a common cause of death in the US. It is obviously of major importance to define the aetiology of deep vein thrombosis (DVT) as (i) many of these events are preventable if appropriate therapy, dependent upon the risk factors known is utilised; (ii) appropriate antithrombotic therapy will decrease risks of recurrence; (iii) the type of defect(s) and risk(s) will determine length of time the patient should remain on therapy for secondary prevention and (iv) if the defect is hereditary appropriate family members can be assessed. Aside from mortality, significant additional morbidity occurs from DVT including, but not limited to, stasis ulcers and other sequelae of post-phlebitic syndrome. Numerous studies have provided evidence that medical patients and patients undergoing surgery or trauma are at significant risk for developing DVT, including pulmonary embolism (PE). Thus, an important task for the clinician is to prevent DVT and its complications. It is important to define risk groups where prophylaxis must be considered. The attitudes and beliefs towards prophylaxis show great regional variations. This is true for the definition of risk groups, the proportion of patients receiving prophylaxis and prophylactic modalities used. For this reason, various 'consensus conference' groups have attempted to alleviate these problems; the primary mission of consensus guidelines is to provide optimal direction to the clinician in the setting of clinical practice. If the practice guidelines generated are successful they will assist clinicians in decision-making for their patients, and they will also provide protection against unjustified malpractice actions. Therapy may be complex, as clinical studies continue to identify more effective treatments. This review includes currently accepted approaches to the treatment of DVT. The clinical course of DVT is highly dynamic. When the response to therapy is not as expected, more than one cause of DVT may be present in a patient. Treatment must address the primary coagulopathy as well as any precipitating factors. The risk of pharmacological intervention must be balanced against potential benefit. If the incidence of DVT in a given disorder is low and if the mortality rate is similarly low, therapy with an agent known to be associated with a high risk for complications, such as warfarin, would not be indicated. If DVT is seen primarily after surgery or in other high-risk situations, therapy might be limited to a fixed time period. However, if the ongoing risk of DVT remains high or if a history of recurrent DVT dictates, lifelong therapy might be indicated. The recommendations presented are based upon published controlled trials; however, indications for therapy and therapeutic agents of choice will continually evolve. By applying the principles outlined in this review, substantial cost savings, reduction in morbidity and reductions in mortality should occur.

Transcatheter aspiration: the key to successful percutaneous treatment of deep venous thrombosis?

RATIONALE AND OBJECTIVES

The purpose of this study was to examine transcatheter aspiration as an adjunct to local thrombolysis in a porcine model of acute deep venous thrombosis (DVT).

MATERIALS AND METHODS

DVT was induced in both hind limbs of five pigs. Thirty minutes later, bilateral thrombolysis was performed by using infusion guidewires placed coaxially through occlusion balloon catheters. A temporary venous filter was then placed in the inferior vena cava. The balloon catheters and infusion wire were removed, a 14-F sheath was placed on the right side, and aspiration of residual thrombi was attempted with 8- and 6-F catheters. At autopsy, the mass of any thrombus in the iliofemoral veins was measured, and residual thrombosis in the venous tributaries was graded at four sites. Thromboemboli in the inferior vena cava and the pulmonary circulation were also collected and weighed.

RESULTS

With aspiration and lysis, the iliofemoral veins were cleared of thrombus in three of five limbs; from the remaining two, only 0.09 and 0.15 g of thrombus were harvested. Except for the deep femoral vein in two legs, tributaries were free of thrombus. After thrombolysis alone, thrombi ranged in mass from 0.54 to 1.14 g (median, 0.70 g). Some thrombi were observed in most tributaries. One or two small emboli were found trapped by the caval filter and in the pulmonary circulation in four and three pigs, respectively.

CONCLUSION

The primary axial veins and their tributaries can be rapidly cleared of thrombus by using thrombolysis with transcatheter aspiration, but this procedure is associated with the risk of pulmonary embolism.