Venous thromboembolism associated with long-term use of central venous catheters in cancer patients

Low-dose warfarin for the prevention of central line-associated thromboses in children with malignancies--a randomized, controlled study

BACKGROUND

Central venous lines (CVLs) are essential in the care of children with malignancies, but are associated with venous thromboembolism (VTE) and infections. Effective and safe prophylactic approaches are deficient.

AIM

To perform a study of adjusted low-dose warfarin for the prevention of CVL-related VTE in children with malignancies.

METHODS

Children with newly diagnosed cancer, a CVL in a jugular vein and an expected treatment period of over 6 mo were eligible for the study. Participants were randomized to low-dose warfarin, with intended international normalized ratio (INR) 1.3-1.9, or to a control group. Primary outcome was VTE in a jugular vein diagnosed by ultrasonography at 1, 3 and 6 mo after inclusion. Secondary outcome was CVL-related infections, mainly measured as days on antibiotics or positive blood cultures.

RESULTS

The study enrolled 73 children, and 62 completed it fully. Asymptomatic CVL-related VTE was frequent (42%), but often transient. Regardless of severity, timing and duration, CVL-related VTE was equally frequent among children on warfarin as compared to controls (p=0.44). Low-dose warfarin (p=0.59) or jugular CVL-related VTE (p=0.91) did not have any impact on days on antibiotics, but we observed a tendency towards an association between CVL-related VTE and positive blood cultures (p=0.15).

CONCLUSION

Our randomized study of low-dose oral anticoagulation for the prevention of CVL-related asymptomatic VTE in children with cancer did not show any benefit of warfarin adjusted to maintain INR between 1.3 and 1.9.

Superior vena cava syndrome related to indwelling intravenous catheters in patients with cystic fibrosis

Patients with cystic fibrosis (CF) often need long-term implanted vascular-access devices for intravenous antibiotics for chronic lower respiratory tract infections. These devices are not without complications, including infection, occlusion, and vascular thrombosis. Such thrombosis can result in superior vena cava (SVC) syndrome due to the position of the catheter proximal to the right atrium. SVC syndrome in CF patients, however, is rarely reported in the literature, suggesting that its incidence is uncommon. We describe three patients with SVC syndrome as a consequence of implanted vascular-access devices.

Tromboembolia venosa en pacientes con cáncer

The association between neoplastic diseases and venous thromboembolism (VTE) is known since long time ago. The nature of this association is bidirectional. On one hand, cancer increases the incidence of venous thrombosis and, on the other hand, the hemostatic system does play a key role in the tumorigenesis process. However, despite recent advances in the field, prophylaxis and treatment of VTE in cancer patients is still a challenge, due to the complexity of this type of patients. This review is focused on some important points regarding management of VTE in cancer patients such as physiopathology, epidemiology, search for hidden malignancy, prognostic impact, prophylaxis in the medical and surgical setting, or initial and long-term treatment.

Long-term, tunneled, noncuffed central venous catheter in cancer patients (Vygon): safety, efficacy, and complications

BACKGROUND

Totally implantable or partially cuffed central venous catheters (CVC) are commonly used in cancer patients, but they are often expensive and may produce complications. To minimize costs, we have been using a low-cost, partially tunneled, silicone elastomer catheter with no Dacron cuff or antireflux valve (Vygon) since 2001. This study is a retrospective investigation of our experience using the Vygon catheter as a long-term CVC in patients with malignancy.

MATERIALS AND METHODS

A total of 458 Vygon catheters (Nutricath, Vygon) were percutaneously inserted by an interventional radiologist in 302 cancer patients. The median duration of catheter use was 93 days, mean 164.3 days (range 1-789). Main patient characteristics were as follows: number of male/female patients, 166/136; median age, 51 years; hematological/nonhematological patients, 189/113.

RESULTS

Early complications were pneumothorax in six and hematoma in twelve of 458 implants, respectively. Thirteen out of 302 patients developed a catheter-related thrombosis. One hundred and thirty-five of 458 Vygon catheters required removal because of catheter-related complications: 68 accidental losses, 37 cases of febrile neutropenia suspected to be catheter-related, ten catheter dislodgements, ten catheter malfunctions, four local infections, three thromboses, two catheter ruptures, and one allergic reaction.

CONCLUSION

Vygon catheters do not seem to induce more early and late complications as compared with other more expensive devices, except for disadvantage of the high incidence rate of accidental losses.

[Effectiveness of heparin versus NaCl 0.9% in central venous catheter flushing. A systematic review]

OBJECTIVE

To determine the effects of intermittent flushing with heparin versus NaCl 0.9% solution on prevention of thrombotic events and infections in central venous catheters.

METHOD

A systematic review of controlled trials, randomized or not, in whose intermittent flushing with heparin versus NaCl 0.9% in central venous catheters were compared was carried out. Any publication was excluded because of patients age, country or language. Studies were identified by computerised searches (MEDLINE and CINAHL 1996-2004, EMBASE Drugs and Pharmacology 1991-2004, Cochrane Library up 2005, ISI Web of knowledge 1990-2004), clinical trials metaregister http://www. controlled-trials.commrct/mrct_info_es.asp, and scanning references.

RESULTS

Only two clinical trials, involving 94 patients, fulfilled inclusion criteria for obstruction. Methodological quality of trials was poor and heterogenicity was also very significant. It made impossible meta-analytical combination of results. No studies comparing heparin vs. NaCl 0.9% solution flushing in catheter-related infection prophylaxis were reported.

CONCLUSIONS

Poor evidence supports effectiveness of intermittent heparin flushing vs. NaCl 0.9% solution, although methodological limitations and small sample size make these findings very inconsistent. In infection prophylaxis, there is no data allowing us to conclude if heparin flushing is more effective than NaCl 0.9% solution. More randomized clinical trials are needed.

XELOX (capecitabine plus oxaliplatin) as first-line treatment for elderly patients over 70 years of age with advanced colorectal cancer

The purpose of this phase II trial was to determine the efficacy and safety of the XELOX (capecitabine/oxaliplatin) regimen as first-line therapy in the elderly patients with metastatic colorectal cancer (MCRC). A total of 50 patients with MCRC aged > or = 70 years received oxaliplatin 130 mg m(-2) on day 1 followed by oral capecitabine 1000 mg m(-2) twice daily on days 1-14 every 3 weeks. Patients with creatinine clearance 30-50 ml min(-1) received a reduced dose of capecitabine (750 mg m(-2) twice daily). By intent-to-treat analysis, the overall response rate was 36% (95% CI, 28-49%), with three (6%) complete and 15 (30%) partial responses. In total, 18 patients (36%) had stable disease and 14 (28%) progressed. The median times to disease progression and overall survival were 5.8 months (95% CI, 3.9-7.8 months) and 13.2 months (95% CI, 7.6-16.9 months), respectively. Capecitabine was well tolerated: grade 3/4 adverse events were observed in 14 (28%) patients: 11 (22%) diarrhoea, eight (16%) asthenia, seven (14%) nausea/vomiting, three (6%) neutropenia, three (6%) thrombocytopenia, and two (4%) hand-foot syndrome. There was one treatment-related death from diarrhoea and sepsis. In conclusion, XELOX is well tolerated in elderly patients, with respectable efficacy and a meaningful clinical benefit response. Given its ease of administration compared with combinations of oxaliplatin with 5-FU/LV, it represents a good therapeutic option in the elderly.

A phase II study of fixed-dose capecitabine and assessment of predictors of toxicity in patients with advanced/metastatic colorectal cancer

The purpose of this study was to evaluate the safety and activity of fixed-dose capecitabine in patients with advanced colorectal cancer and to correlate pretreatment plasma concentrations of homocysteine and serum and red cell folate with toxicity. Patients received capecitabine 2000 mg (4 x 500 mg tablets) twice daily on days 1-14 every 3 weeks. They were reviewed weekly during the first cycle and then three weekly for safety assessment. Eligibility criteria were advanced/metastatic colorectal cancer, < or = 2 prior chemotherapy regimens, ECOG performance status 0-2 and life expectancy >12 weeks. A total of 60 patients were enrolled and 55 were evaluable for efficacy. The median age was 72 years and 63% of patients had a performance status of 1 or 2. Confirmed tumour responses were reported in 15 patients (28%; 95% confidence interval (CI), 15.7-40.3%). The median time to disease progression was 4.9 months and median overall survival was 11.2 months. The median ratio of fixed dose to body surface area (BSA)-calculated dose was 88% (range 65-108%). Significant myelosuppression was not observed. Grade 2/3 treatment-related adverse events were diarrhoea (34%), fatigue (27%), stomatitis (15%) and hand-foot syndrome (22%). Dose reduction due to adverse events was required in 16 patients (29%) and multiple reductions in five patients (9%). There was no grade 3/4 haematological toxicity, any grade 4 adverse events or treatment-related deaths. Patients with higher pretreatment levels of serum folate experienced significantly greater toxicity (P = 0.02, CI: 1.0-1.2) during cycle 1 and over the entire treatment period (P = 0.04, CI: 1.0-1.3). Pretreatment homocysteine concentrations did not predict for toxicity. In conclusion, fixed-dose capecitabine appears to have similar efficacy and safety compared to the currently recommended dose schedule based on body surface area and simplifies drug administration. A high pretreatment folate may be predictive of increased toxicity from capecitabine.

Thrombotic effects of asparaginase in two acute lymphoblastic leukemia protocols (NOPHO ALL-1992 versus NOPHO ALL-2000): a single-institution study

Asparaginase is essential in the treatment of lymphoproliferative malignancies, but it is associated with several side effects. The objective of this study was to compare asparaginase-induced alterations of the coagulation inhibitors and the impact on central line-associated thrombosis in children treated according to 2 different asparaginase regimens. The study enrolled 30 children treated for acute lymphoblastic leukemia, and they were divided into 2 groups with respect to asparaginase preparation and protocol (NOPHO ALL-1992 versus NOPHO ALL-2000). The coagulation inhibitors antithrombin, protein C, and proteins S were measured prior to and during asparaginase therapy, and incidence of central line-associated thromboses was compared to evaluate the protocols' thrombogenicity. Thirteen children received Erwinia asparaginase and 17 children received E. coli asparaginase. Independent of protocol, the coagulation inhibitors were significantly reduced during asparaginase therapy (p < .001), and central line-associated thromboses were frequent. Four children developed thrombosis in the course of asparaginase therapy, and there was a correlation between asparaginase-induced fall of antithrombin and occurrence of new thromboses (p = .01).

Incidence, risk factors, and outcomes of catheter-related thrombosis in adult patients with cancer

PURPOSE

Thrombosis of long-term central venous catheters (CVC) is a serious complication that causes morbidity and interrupts the infusion of chemotherapy, intravenous medication, and blood products. We performed a prospective study to examine the incidence, risk factors, and long-term complications of symptomatic catheter-related thrombosis (CRT) in adults with cancer.

PATIENTS AND METHODS

Consecutive patients with cancer, undergoing insertion of a CVC, were enrolled and prospectively followed while their catheter remained in place plus 4 subsequent weeks or a maximum of 52 weeks, whichever came first. Patients with symptomatic CRT were followed for an additional 52 weeks from the date of CRT diagnosis. The end points were symptomatic CRT, symptomatic pulmonary embolism (PE), postphlebitic syndrome, and catheter life span.

RESULTS

Over 76,713 patient-days of follow-up, 19 of 444 patients (4.3%) had symptomatic CRT in 19 of 500 catheters (0.3 per 1,000 catheter-days). The median time to CRT was 30 days and the median catheter life span was 88 days. Significant baseline risk factors for CRT were: more than one insertion attempt (odds ratio [OR] = 5.5; 95% CI, 1.2 to 24.6; P = .03); ovarian cancer (OR = 4.8; 95% CI, 1.5 to 15.1; P = .01); and previous CVC insertion (OR = 3.8; 95% CI, 1.4 to 10.4; P = .01). Nine of the 19 CRT patients were treated with anticoagulants alone, eight patients were treated with anticoagulants and catheter removal, while two patients did not receive anticoagulation. None had recurrent CRT or symptomatic PE. Postphlebitic symptoms were infrequent.

CONCLUSION

In adults with cancer, the incidence of symptomatic CRT is low and long-term complications are uncommon.

Cancer-associated thrombosis

Thrombosis is one of the major complications of malignant disease, but the underlying molecular and cellular basis remains elusive. A number of hypotheses have been put forth, including the expression of tissue factor by tumor cells, release of tissue factor during cell death following chemotherapy, intrinsic unique tumor procoagulants and microparticles. Exploration of a potential role of microparticles in cancer-associated thrombosis indicates that tissue factor microparticles are present in a spectrum of cancer patients known to have a high incidence of thromboembolic complications.

The integration of oral capecitabine into chemoradiation regimens for locally advanced rectal cancer: how successful have we been?

The aim was to review available literature on capecitabine-based chemoradiation regimens for the preoperative treatment of patients with locally advanced rectal cancer (LARC) and determine efficacy and safety data for capecitabine in this setting. Medical literature databases (Pubmed, Medline) and abstracts/posters presented at recent scientific congresses (ASCO, ASTRO, ESTRO and ECCO) were screened and critically analysed to identify relevant data. A number of phase I/II studies have demonstrated that capecitabine is effective and well tolerated in combination with preoperative radiotherapy in patients with LARC. Phase III studies are ongoing. Continuous oral administration of capecitabine (825 mg/m(2) twice daily for 7 days/week) is an effective regimen and has similar tolerability to the less dose-intensive intermittent regimens of capecitabine given 5 days/week followed by 2 day's rest or 14 days followed by 7 day's rest as used in systemic chemotherapy for patients with colorectal or breast cancer. Capecitabine chemoradiation is associated with a relatively low rate of grade 3/4 adverse events. Capecitabine simplifies chemoradiation and provides a convenient treatment option for both patients and health care professionals. Combining capecitabine with cytotoxic agents such as oxaliplatin and irinotecan has the potential to further improve antitumour efficacy in patients receiving preoperative chemoradiation. Data from phase I/II single-agent and combination capecitabine chemoradiation studies provide a clear rationale for replacing infusional 5-FU with oral capecitabine as part of chemoradiation for patients with LARC.

Fatal postoperative pulmonary embolism in mild haemophilia

The use of thromboprophylaxis in patients with haemophilia receiving factor replacement is often not considered necessary, but remains an area of debate. In this report we describe a patient with mild haemophilia A, who underwent major pelvic surgery. He had several underlying risk factors associated with the development of thromboembolism, and ultimately died as a direct consequence of multiple pulmonary emboli. The need for thromboprophylaxis and the risk balance ratio should always be considered in patients with bleeding disorders if they fall into what would otherwise be high-risk category for hospital acquired venous thromboembolism.

Incidence of venous thromboembolism following major abdominal surgery: a multi-center, prospective epidemiological study in Japan

BACKGROUND

Venous thromboembolism (VTE) has been considered to be a rare surgical complication in Japan.

AIM

To investigate the incidence and risk factors of VTE in Japanese patients undergoing major abdominal surgery.

METHODS

A prospective, multi-center epidemiological study was conducted from December, 2001 to August 2002 in 39 medical institutes throughout Japan. A total of 173 patients with general (n = 128), gynecologic (n = 23), and urologic (n = 22) surgery were analyzed. For the diagnosis of deep vein thrombosis (DVT), bilateral venography was performed in all patients. Lung ventilation/perfusion scintigraphy was carried out in patients suspected of pulmonary thromboembolism (PTE).

RESULTS

There were 36 patients with distal DVT (20.8%) and five patients with proximal DVT (2.9%). One patient was diagnosed as PTE. Overall, VTE was diagnosed in 42 patients (24.3%). By univariate analysis, only age (60 years or older) was identified as a significant risk factor in the whole study population. When analyzed by the stepwise multiple logistic regression model, female gender, operation site, age, and operation time were four risk factors found to be significant. The incidence of VTE was closely related to the number of risk factors that patients had. As many as 44% of patients with three or four risk factors developed VTE while those with one or two risk factors showed about a 17% incidence of VTE. Four patients lacking any risk factors did not develop VTE.

CONCLUSIONS

Venous thromboembolism is common in Japanese patients undergoing major abdominal surgery. Pharmacologic thromboprophylaxis is considered essential, particularly in those patients with multiple, potential risk factors.

Diagnosis of aseptic deep venous thrombosis of the upper extremity in a cancer patient using fluorine-18 fluorodeoxyglucose positron emission tomography/ computerized tomography (FDG PET/CT)

We describe a patient with a history of recurrent squamous cell carcinoma of the tongue and abnormal FDG uptake in the left arm during a re-staging FDG PET/CT. After revision of the patient's clinical history, tests and physical exam, the abnormal FDG uptake was found to correspond to an extensive aseptic deep venous thrombosis of the upper extremity.

Phase II randomised trial of raltitrexed-oxaliplatin vs raltitrexed-irinotecan as first-line treatment in advanced colorectal cancer

The purpose of this phase II randomised trial was to determine which of two schemes, raltitrexed-irinotecan or raltitrexed-oxaliplatin, offered better activity and less toxicity in patients with advanced colorectal cancer (CRC). A total of 94 patients with previously untreated metastatic CRC were included and randomised to receive raltitrexed 3 mg m⁻² followed by oxaliplatin 130 mg m⁻² on day 1 (arm A), or CPT-11 350 mg m⁻² followed by raltitrexed 3 mg m⁻² (arm B). In both arms treatment was repeated every 3 weeks. Intent-to-treat (ITT) analysis showed an overall response rate of 46% (95% CI, 29.5–57.7%) for arm A, and 34% (95% CI, 19.8–48.4%) for arm B. Median time to progression was 8.2 months for arm A and 8.8 months for arm B. After a median follow-up of 14 months, 69% of patients included in arm A were still alive, compared to 59% of those included in arm B. Overall, 31 patients (65%) experienced some episode of toxicity in arm A and 32 patients (70%) in arm B, usually grade 1–2. The most common toxicity was hepatic, with 29 patients (60%) in arm A and 24 patients (62%) in arm B, and was grade 3–4 in four (8%) and four (9%) patients, respectively. In all, 14 patients (29%) from arm A and 24 patients (52%) from arm B had some grade of diarrhoea (P<0.03). Neurologic toxicity was observed in 31 patients (64%) in arm A, and was grade 3–4 in five patients (10%), while a cholinergic syndrome was detected in nine patients (19%) in arm B. There were no differences in haematologic toxicity. One toxic death (2%) occurred in arm A and three (6.5%) in arm B. In conclusion, both schemes have high efficacy as first-line treatment in metastatic CRC and their total toxicity levels are similar. Regimens with raltitrexed seem a reasonable alternative to fluoropyrimidines.

A randomised cross-over trial comparing patient preference for oral capecitabine and 5-fluorouracil/leucovorin regimens in patients with advanced colorectal cancer

BACKGROUND

Traditionally, metastatic colorectal cancer (MCRC) has been treated with intravenous (i.v.) 5-fluorouracil/leucovorin (5-FU/LV). The tumour-activated, oral fluoropyrimidine capecitabine demonstrates superior activity and favourable safety compared with the Mayo regimen, while potentially avoiding the complications and inconvenience associated with i.v. regimens.

PATIENTS AND METHODS

Ninety-seven patients with previously untreated advanced/MCRC were randomised to receive capecitabine followed by i.v. 5-FU/LV [Mayo Clinic, in-patient de Gramont (IPdG) or out-patient modified de Gramont (OPdG) regimens], or i.v. 5-FU/LV followed by capecitabine.

RESULTS

Before treatment, of those patients for whom a preference was recorded, almost all (95%) preferred oral treatment (consistent across all treatment groups) and the majority retained this preference after treatment (64% overall; 86%, 63% and 50% in the Mayo, IPdG and OPdG groups, respectively). Following treatment, the principal reasons for oral treatment preference were increased convenience, home-based administration and tablet formulation. Treatment satisfaction was significantly higher with capecitabine compared with Mayo (P<0.05) and with OPdG compared with capecitabine (P<0.05). Quality of life (QoL) was largely constant across the regimens, although it appeared better with OPdG than capecitabine (P<0.05). Grade 3/4 adverse events were uncommon in all arms.

CONCLUSIONS

This study confirmed that the majority of patients with MCRC prefer oral to i.v. therapy, although the OPdG regimen appears to be the most popular i.v. option. Capecitabine clearly represents an effective, well-tolerated oral alternative to i.v. 5-FU/LV.

Therapeutic Options for the Treatment of Cancer-Associated Thrombosis

OBJECTIVE

To provide oncology nurses with an understanding of therapeutic options for cancer-associated thrombosis, strategies to prevent recurrence, and practical issues in patient management.

DATA SOURCES

Primary and tertiary literature and the author's clinical experience.

CONCLUSION

Oncology nurses monitor patients throughout the care continuum for signs and symptoms indicating vascular thromboembolism and need to know the steps to take to expedite an accurate diagnosis and ensure prompt treatment.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses must keep informed about the evolving evidence that leads to practice changes. They should be able to teach patients about therapeutic options and their potential for improving outcomes.

Abnormal Clotting in Cancer: An Overview of Pathophysiology and Etiology

OBJECTIVE

To help oncology nurses become more cognizant of the increased risk cancer patients have for venous thromboembolism due to such factors as chemotherapy and hypercoagulability stemming from the neoplasm itself.

DATA SOURCES

Primary and tertiary literature and the author's clinical experience.

CONCLUSION

Establishing the optimal treatment of cancer-associated thrombosis in the future will depend in part on a better understanding of clotting aberrations. Oncology nurses must be cognizant of the various risk factors for thrombosis and bleeding and how they relate to cancer treatments and interventions.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses are in a unique position to recognize conditions that predispose cancer patients to the development of venous thromboembolism as well as its signs and symptoms. This enhanced understanding will ensure that patients receive appropriate and timely intervention.

Dalteparin for prevention of catheter-related complications in cancer patients with central venous catheters: final results of a double-blind, placebo-controlled phase III trial

BACKGROUND

Cancer patients receiving chemotherapy experience thromboembolic complications associated with the use of long-term indwelling central venous catheters (CVCs). This prospective, double-blind, placebo-controlled, multicenter study evaluated whether prophylactic treatment with a low molecular weight heparin could prevent clinically relevant catheter-related thrombosis.

PATIENTS AND METHODS

Patients with cancer undergoing chemotherapy for at least 12 weeks (n=439) were randomly assigned, in a 2:1 ratio, to receive either dalteparin (5000 IU) or placebo, by subcutaneous injection, once daily for 16 weeks. Patients underwent upper extremity evaluation with either venography or ultrasound at the time of a suspected catheter-related complication (CRC) or upon completion of study medication. The primary end point, as determined by a blinded adjudication committee, was the occurrence of a CRC, defined as the first occurrence of any one of the following: clinically relevant catheter-related thrombosis that was symptomatic or that required anticoagulant or fibrinolytic therapy; catheter-related clinically relevant pulmonary embolism; or catheter obstruction requiring catheter removal.

RESULTS

There was no significant difference in the frequency of CRCs between the dalteparin arm (3.7%) and the placebo arm (3.4%; P=0.88), corresponding to a relative risk of 1.0883 (95% confidence interval 0.37-3.19). No difference in the time to CRC was observed between the two arms (P=0.83). There was no significant difference between the dalteparin and placebo groups in terms of major bleeding (1 versus 0) or overall safety.

CONCLUSIONS

Dalteparin prophylaxis did not reduce the frequency of thromboembolic complications after CVC implantation in cancer patients. Dalteparin was demonstrated to be safe over 16 weeks of treatment in these patients.

A review of the risks and benefits of differing prophylaxis regimens for the treatment of deep venous thrombosis and pulmonary embolism in neurosurgery

BACKGROUND

Annually, 2 million people in the United States develop deep venous thrombosis (DVT), and nearly 100,000 sustain fatal pulmonary emboli. Prophylaxis against DVT/pulmonary embolism (PE) is a critical issue, and options include elastic stockings, intermittent pneumatic compression stockings, low-dose unfractionated heparin (5000 U every 8-12 hours), and low molecular-weight heparin (ie, enoxaparin and dalteparin). The risks and benefits associated with different prophylaxis regimens used in the prevention of DVT and PE in neurosurgical procedures were analyzed.

METHODS

Neurosurgical studies focusing on different methods of prophylaxis used for the prevention of DVT and PE were reviewed. The efficacy, risks, and benefits of varied treatment options were evaluated, with particular emphasis on minor and major hemorrhages occurring where heparin-based protocols were used.

RESULTS

In Flinn et al series (Arch Surg. 1996;131(5):472-80), the incidence of DVT was greater for cranial (7.7%) than spinal procedures (1.5%). Although intermittent pneumatic compression devices provided adequate reduction of DVT/PE in some cranial and combined cranial/spinal series, low-dose subcutaneous unfractionated heparin or low molecular-weight heparins further reduced the incidence, not always of DVT, but of PE (Br J Neurosurg 1995;9(2):159-63; J Intensive Care Med 2003;18(2):59-79). Nevertheless, low-dose heparin-based prophylaxis in cranial and spinal series risks minor and major postoperative hemorrhages: 2% to 4% in a cranial series, 3.4% minor and 3.4% major hemorrhages in a combined cranial/spinal series, and a 0.7% incidence of major/minor hemorrhages in a spinal series (J Neurosurg 2003;99(4):680-4; Neurosurgery 1986;18(4):440-5; Eur Spine J 2004;13(1):1-8; J Intensive Care Med 2003;18(2):59-79).

CONCLUSIONS

Although mechanical prophylaxis provided effective prophylaxis against DVT/PE in many series, the added efficacy of low-dose heparin regimens has to be weighed against risks of major postoperative hemorrhages and their neurological sequelae.

Intermittent pneumatic compression stocking prophylaxis against deep venous thrombosis in anterior cervical spinal surgery: a prospective efficacy study in 200 patients and literature review

STUDY DESIGN

Intermittent pneumatic compression stockings (IPC) alone were prospectively used to avoid deep venous thrombosis (DVT) and pulmonary embolism (PE) in 100 consecutive patients undergoing single-level anterior corpectomy/fusion (ACF) and in 100 patients having multilevel ACF/posterior fusion.

OBJECTIVES

To determine the optimal prophylaxis against DVT and PE for patients undergoing anterior cervical spinal surgery.

BACKGROUND DATA

Mini-heparin and low-dose heparin prophylaxis in neurosurgery poses a 2% to 4% risk of major postoperative hemorrhage with resultant neurologic sequelae.

METHODS

Prophylaxis consisted of IPC alone. Doppler studies of the lower extremities were routinely obtained 2 days after surgery. Single-level ACF (100 patients) addressed two-level disc disease, spondylostenosis, and ossification of the posterior longitudinal ligament (OPLL). One hundred patients undergoing multilevel ACF (3+ levels) with posterior fusion (C2-T1) exhibited OPLL/spondylostenosis.

RESULTS

One patient undergoing single-level ACF developed DVT/PE 6 days after surgery; she exhibited Factor V Leiden mutation (hypercoagulability syndrome). Although 7 patients undergoing circumferential surgery developed DVT 2 to 14 days following surgery (mean, 7.15 days), only two clots localized in the iliac veins resulted in PEs (days 10 and 14 after surgery).

CONCLUSIONS

IPCs were as effective for prophylaxis against DVT/PE for 100 patients undergoing single-level ACF and for 100 having circumferential procedures as existing therapies (mini-heparin and low-dose heparin), without the risk of hemorrhage. However, the 1% and 2% respective rates of PE were comparable to frequencies of PE encountered in other cranial/spinal series using mini-heparin and/or low-dose heparin regimens but avoided the 2% to 4% risk of major postoperative hemorrhage.

Vena cava filters in cancer patients: experience with 50 patients

OBJECTIVE

To study the immediate and late results obtained from the implantation of vena cava filters in cancer patients with deep vein thrombosis concomitant with neoplasia.

METHODS

This was a retrospective evaluation of 50 patients with an association of cancer and deep venous thrombosis who underwent interruption of the inferior vena cava and the insertion of permanent vena cava filters. The indications for the procedure, filter implantation technique, early and late complications related to the operation, and the clinical evolution were evaluated.

RESULTS

The most frequent indication for filter implantation was the contraindication for full anticoagulant treatment (80%). The femoral vein was the preferred access route (86% of the patients). There were no complications related to the surgical procedure. During the follow-up, the following complications were observed: 1 episode of nonfatal pulmonary thromboembolism, 2 cases of occlusion of the inferior vena cava, and 1 case of thrombus retained in the device. Twenty patients (40%) died due to progression of the neoplasm.

CONCLUSIONS

Interruption of the inferior cava vein using an endoluminal filter is a procedure with a low rate of complications. It is a safe and efficient measure for preventing pulmonary embolism in cancer patients who have deep vein thrombosis of the lower limbs.

Optimisation de l’interrogatoire dans l’évaluation du risque de maladie thromboembolique veineuse : l’étude OPTIMEV

Venous thromboembolism (VTE) is a frequent disease and remains a major cause of mortality and morbidity among our patients. During the 20 past years, clinical description, diagnostic tools, and treatment have changed dramatically. Most published data describing risk factors for VTE no longer apply to the patients seen in daily practice. We present here the rationale, aims, and methodology of the OPTIMEV Study (OPTimisation de l'Interrogatoire pour la Maladie thromboEmbolique Veineuse).

RATIONALE

Risk factors for VTE are numerous, complex and interactions between them and their clinical importance is difficult to measure (table I). For example, odds ratios for VTE recurrence vary greatly across longitudinal studies. We searched the National Library of Medecine (PubMed) and the Amedeo website using the following keywords: "venous thromboembolism", "pulmonary embolism", "deep vein thrombosis", "risk factors". We selected 84 relevant articles published between 1972 and 2005. Based on this literature analysis, we identified the following major risk factors: VTE recurrence, surgery, cancer, immobilization, age, biological factors. For these factors, data are lacking and some questions are proposed.

OBJECTIVES

The broad objective of the study is to better evaluate clinical risk factors that fit today's practice against VTE. Specific aims are: 1) to determine whether risk factors are different between proximal and distal deep vein thrombosis (DVT); 2) to develop and prospectively validate a new prediction rule for outpatients. The primary hypothesis is that careful assessment of VTE recurrence, adequate surgical thromboprophylaxis, cancer staging, and varicose vein stratification according to the CEAP classification, is mandatory for accurate evaluation of thromboembolic disease risk.

METHODS

We conducted a multicenter, prospective, cohort study of 10000 patients. Enrollees are inpatients and outpatients presenting with a clinical suspicion of VTE in Emergency Departments and outpatient clinics in France. 4173 patients have been enrolled at this time (Figure 2). All eligible patients are enrolled during a selected period of time through different seasons. Data are collected by physicians in charge of the patients using an electronic case recording form. Collected data include baseline characteristics, risk factors, results of diagnostic investigations. Outcome measures obtained through telephone interview at 3 and 12 months include cancer diagnosis, VTE recurrence, haemorrhagic events, treatments, death. Univariate and multivariate analysis will be performed using multilevel logistic regression. The study organization is performed by the Centre d'Investigation Clinique de Grenoble and is sponsored by the French Society of Vascular Medicine. First results, to be published in 2006, will allow development of new prediction rules for VTE diagnosis.

Age, cancer and the risk of venous thromboembolism

Cancer increases the risk for venous thromboembolism (VTE) and patients presenting with a seemingly idiopathic VTE often have an occult cancer. Aging also is a risk factor for VTE. Therefore, old patients with cancer are supposed to be at very high risk for VTE, but inherent data are sporadic and contrasting. We reviewed the literature about the relation between cancer and VTE, with particular attention to findings concerning elderly patients. While aging and postmenopausal status enhance the risk of chemotherapy-induced VTE in women with breast cancer, the rate of a cancer diagnosis in the first year after VTE seems to be even lower in elderly compared to young subjects. Thus, further studies are needed to understand whether or not aging and cancer have additive thrombogenic effects. Finally, we discuss prophylactic and therapeutic strategies.

A single institution experience with concurrent capecitabine and radiation therapy in weak and/or elderly patients with urothelial cancer

PURPOSE

To describe a single institution experience in delivering concurrent capecitabine and radiation in elderly patients with urothelial cancer.

METHODS AND MATERIALS

The records of patients with urothelial carcinoma treated with capecitabine and radiation at Wayne State University were reviewed. Capecitabine was administered at a median dose of 1600 mg/m2/day (range, 1200-1800 mg/m2). Concurrent radiation therapy (RT) of 40-45 Gy was delivered to a small pelvic field with a four-field technique, with additional boost to tumor area (total, 54-68.4 Gy).

RESULTS

Fourteen patients who were not candidates for cystectomy or cisplatin-based therapy were treated with capecitabine and concurrent radiation therapy. Median age was 80 years (range, 46-88 years). Five patients had a performance status of 3. Nine patients had localized disease, and 5 patients had advanced disease. The most common overall toxicities were fatigue (43%), diarrhea (Grade 2, 14% and Grade 3, 29%), and dehydration (43%), with no Grade 4 or 5 toxicities. Of 14 patients, 3 (20%) required hospitalization for management of toxicities. Seven patients required dose modification, and the therapy was relatively well tolerated. Clinical complete response was seen in 11 of 13 evaluable patients (77%). At a median follow-up of 10.5 months, only 3 of 11 responders had relapsed.

CONCLUSION

Concurrent capecitabine and radiation therapy is well-tolerated and demonstrates promising efficacy in urothelial carcinoma, thus offering a tolerable therapeutic option in elderly patients or those with impaired performance status.

Capecitabine/Oxaliplatin, a Safe and Active First-Line Regimen for Older Patients Metastatic Colorectal Cancer: Post Hoc Analysis of a Large Phase II Study

PURPOSE

The tumor-activated fluoropyrimidine capecitabine achieves response rates superior to those of bolus 5-fluorouracil/leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer (CRC), with favorable safety and fewer hospitalizations. Capecitabine is also at least as effective as bolus 5-FU/LV in the adjuvant setting, again with a favorable safety profile. Improved outcomes with capecitabine versus bolus 5-FU/LV in the adjuvant setting have been shown in overall trial populations and in patients aged >or= 70 years. Capecitabine/oxaliplatin (XelOx) is a safe and active combination for the first-line treatment of metastatic CRC.

PATIENTS AND METHODS

This post hoc analysis of a large phase II trial compared data from older and younger patients treated with first-line XelOx: oxaliplatin 130 mg/m(2) intravenously on day 1 followed by oral capecitabine 1,000 mg/m(2) twice daily for 14 days every 3 weeks.

RESULTS

The median age of the overall population (N = 96) was 64 years (range, 34-79 years), including 52 younger patients (< 65 years of age) and 44 older patients (>or= 65 years of age). Both age groups received a median of 8 cycles (range, 1-26 cycles) of XelOx. The XelOx regimen had similar high activity in both groups, with response rates of 58% (95% CI, 43%-71%) and 52% (95% CI, 37%-68%) in younger and older patients, respectively. In addition, time to disease progression and overall survival were similar in both groups (P > 0.5 for both outcomes). The XelOx regimen also had a favorable safety profile, with no clinically relevant differences between older and younger patients. The overall incidence of adverse events (including grade 3/4), dose reductions, and withdrawals because of adverse events were similar in both groups.

CONCLUSION

In the context of an aging population, XelOx provides a highly effective and tolerable first-line treatment for patients with metastatic CRC.

Cancer and venous thromboembolism

Venous thromboembolism occurs commonly in patients with cancer. The pathogenetic mechanisms of thrombosis involve a complex interaction between tumour cells, the haemostatic system, and characteristics of the patient. Among risk factors for thromboembolism are long-term immobilisation, especially in hospital, surgery, and chemotherapy with or without adjuvant hormone therapy. Although prophylaxis and treatment of thromboembolism in patients with cancer draw on the agents that are commonly used in those without cancer, there are many special features of patients with cancer that make use of these drugs more challenging. Low-molecular-weight heparins are the cornerstone of prophylaxis and treatment of venous thromboembolism in patients with cancer. These drugs have the potential to increase survival, at least in patients with more favourable outlook. About 10% of patients with idiopathic venous thromboembolism have an underlying malignant disorder that can be detected by extensive diagnostic investigation. However, the issue of whether screening for occult malignant disease ultimately improves prognosis and survival remains to be resolved.

Enoxaparin for the Prevention of Venous Thromboembolism Associated With Central Vein Catheter: A Double-Blind, Placebo-Controlled, Randomized Study in Cancer Patients

Purpose

The extent of venous thromboembolism (VTE) associated with central vein catheters (CVC) in cancer patients remains unclear. The aim of this study was to evaluate the efficacy and safety of the low molecular weight heparin, enoxaparin, in the prevention of VTE.

Patients and Methods

In a multicenter, double-blind study, consecutive cancer patients scheduled for CVC insertion were randomly assigned to receive either subcutaneous enoxaparin 40 mg once a day or placebo. Treatment was started 2 hours before CVC insertion and continued for 6 weeks. The primary end points of the study were deep vein thrombosis (DVT), confirmed by venography of the CVC limb performed 6 weeks after randomization, or clinically overt pulmonary embolism, confirmed by objective testing during the study drug administration. Patients were assessed for bleeding complications.

Results

Three hundred eighty-five patients were randomized, of which 321 (83.4%) underwent venography. A venography was adequate for adjudication in 155 patients in each treatment group. A DVT was observed in 22 patients (14.1%) treated with enoxaparin and in 28 patients (18.0%) treated with placebo, corresponding to a relative risk of 0.78 (95% CI, 0.47 to 1.31). No major bleeding occurred. Five patients (2.6%) in the enoxaparin group and two patients (1.0%) in the placebo group died during the treatment period.

Conclusion

In this study, no difference in the rate of CVC-related VTE was detected between patients receiving enoxaparin and patients receiving placebo. The dose of enoxaparin used in this study proved to be safe. Clinical trials evaluating higher enoxaparin doses could optimize the efficacy of this agent for this indication.

Capecitabine as first-line treatment for patients older than 70 years with metastatic colorectal cancer: an oncopaz cooperative group study

PURPOSE

To determine the tolerability of capecitabine in elderly patients with advanced colorectal cancer (CRC).

PATIENTS AND METHODS

Fifty-one patients with advanced CRC who were >/= 70 years and considered ineligible for combination chemotherapy received oral capecitabine 1,250 mg/m(2) twice daily on days 1 to 14 every 3 weeks. Patients with a creatinine clearance of 30 to 50 mL/min received a dose of 950 mg/m(2) twice daily.

RESULTS

A total of 248 cycles of capecitabine were administered (median, five cycles; range, one to eight cycles). The overall response rate was 24% (95% CI, 15% to 41%), including two complete responses (CR; 4%) and 10 partial responses (PR; 20%). Disease control (CR + PR + stable disease) was achieved in 67% of patients. The median times to disease progression and overall survival were 7 months (95% CI, 6.4 to 9.5 months) and 11 months (95% CI, 8.6 to 13.3 months), respectively. Of the 35 patients evaluated for clinical benefit response, 14 (40%; 95% CI, 24% to 58%) showed clinical benefit. Capecitabine was well tolerated. Treatment-related grade 3 and 4 adverse events were observed in only six patients (12%), and the most common events were diarrhea, hand-foot syndrome, and thrombocytopenia. One patient (2%) had an episode of angina, but no treatment-related deaths were reported.

CONCLUSION

Our findings suggest that capecitabine is effective and well tolerated in elderly patients with advanced CRC who are considered ineligible for combination chemotherapy.

Incidence of thrombotic complications in patients with haematological malignancies with central venous catheters: a prospective multicentre study

This prospective, observational and multicentre study assessed the incidence of, and risk factors for, symptomatic venous thrombotic complications after central venous catheter (CVC) positioning in patients with haematological malignancies. A total of 458 consecutive CVC insertions were registered in 416 patients (81.2% of whom had severe thrombocytopenia). Over the observation period (3 months or up to catheter removal), the incidence of events was: CVC-related deep vein thrombosis (DVT), 1.5%; lower limb DVT, 0.4%; pulmonary embolism (PE), 1.3%; fatal PE, 0.6%; CVC-related superficial thrombophlebitis, 3.9%; CVC-occlusion/malfunction of thrombotic origin, 6.1%; major arterial events, 1.1%. Severe bleeding and CVC-related infections were observed in 3.5% and 4.6% of cases respectively. A composite end point (any venous thromboembolism or superficial thrombophlebitis or CVC occlusion/malfunction) was defined in order to consider venous thrombotic events with a significant impact on clinical practice. With this criterion, the overall incidence was 12.0% (2.54 cases/1000 catheter days). No factor helped to predict venous thrombotic complications: only thrombocytopenia was associated with a weak trend for a reduced risk (odds ratio 0.52; 95% confidence interval 0.26-1.07). No severe bleeding was observed in those patients who received antithrombotic prophylaxis. This study shows that the impact on clinical practice of symptomatic CVC-related thrombotic complications is not negligible in patients with haematological malignancies.

Deep vein thrombosis in cancer: the scale of the problem and approaches to management

Patients with cancer have long been recognised to be at high risk of venous thromboembolism (VTE), although the condition remains under diagnosed and under treated in these patients. As a consequence, the morbidity and mortality due to deep venous thrombosis and pulmonary embolism remains unacceptably high in this group. Furthermore, the management of VTE in the presence of malignancy is complex, due both to the effects of the cancer itself and its treatments. Conventional long-term management of VTE involves the use of vitamin K antagonists (VKAs), such as warfarin, to reduce the risk of recurrence. However, this approach is associated with a range of practical difficulties including the need for regular laboratory monitoring, the potential for drug interactions, in addition to the risk of treatment resistance and bleeding in patients with cancer. Recent research indicates that the use of low molecular weight heparin (LMWH) therapy instead of VKAs may be beneficial in these patients. In particular, evidence from a large clinical trial of the LMWH dalteparin indicates that this agent offers an effective alternative to VKAs in the long-term management of VTE, that is free from the practical problems associated with the use of VKAs and without increasing the risk of bleeding.

Safety of low-dose low-molecular-weight-heparins in thrombocytopenic stem cell transplantation patients: a case series and review of the literature

Few attempts have been made to examine the feasibility of safely administering low-molecular-weight-heparins (LMWHs) in the presence of concurrent thrombocytopenia. We retrospectively investigated the safety of low-dose LMWH in BMT patients, a population at risk of bleeding. In total, 26 patients received at least one dose of low-dose enoxaparin (ie <1 mg/kg/day) during thrombocytopenia. s.c. enoxaparin 40 mg once daily was given in 85% of the cohort. The mean number of platelet days <55 x 10(9) and <20 x 10(9)/l were 16.5 days (95% CI=8.04-24.96) and 4.14 days (95% CI=2.35-5.93), respectively. The mean number of low-dose enoxaparin administration days when platelet <55 x 10(9) and 20 x 10(9)/l were 9.89 days (95% CI=3.26-16.53) and 2.25 days (95% CI=0.57-3.93), respectively. Minor bleeding occurred in four patients (15%) whereas major episodes developed in two patients (8%). The latter two events occurred during the transition between full therapeutic (ie 1.5-2 mg/kg/day) and low-dose enoxaparin close to the onset of thrombocytopenia. The present case series, along with the discussed literature, descriptively suggests that low-dose enoxaparin may be safely administered at a platelet count in the range of 20 and 55 x 10(9)/l in BMT patients who weigh >55 kg.

Traitement de la maladie thromboembolique veineuse chez les patients souffrant de cancers

PURPOSE

Venous tromboembolic treatment in patients with cancer can be a clinical dilemma. Comorbid conditions, significant risk of recurrence of bleeding associated with warfarin, difficult venous access, are some of the factors that often complicate anticoagulants therapy in patients with cancer.

EXEGESIS

Low molecular weight heparin has replaced unfractionated heparin as the first line treatment in the majority of patients with venous thromboembolism and cancer, in hospital or safely at home. Recent trial demonstrated that long-term low molecular weight heparin administrated over a 6-month period reduced the rate of recurrence venous thromboembolism with non increase in bleeding compared with oral anticoagulant therapy. Placement of an inferior vena caval filter should be reserved for patients with active or very high risk of bleeding, but oncologist should consider these sobering results in such patients. Whether anticoagulants might also improve cancer survival rates independent of their effect on thromboembolism deserves further investigation.

PERSPECTIVE

In future, new antithrombotic agents such as oral direct thrombin or long-acting synthetic factor Xa inhibitor may be useful in these patients.

Haemophilia and thrombophilia: an unexpected association!

In patients with haemophilia, a close correlation is usually observed between the clinical expression of the disease and plasmatic factor VIII/factor IX clotting activity. However, some patients experience milder bleeding phenotypes than others, although they exhibit a similar biological profile. The high prevalence of some inherited thrombophilia risk factors offers the possibility of a co-inheritance in haemophilic patients which could influence the phenotypic expression of the disease. Rare thrombotic complications occurring in haemophiliacs could also be facilitated by the co-inheritance of modifier genes. The majority of thrombotic events occurring in haemophiliacs are in relation to clotting factor infusions or central venous catheters. Concerning surgical situations, in the absence of therapeutic recommendations, postoperative thromboprophylaxis is not systematically performed in haemophiliacs. However, substitutive treatment more or less completely corrects the coagulation defect and makes the venous thrombosis risk closer to the control population. It should be emphasized that haemophilia does not fully protect against venous thromboembolic disease. Patients with haemophilia very infrequently experience thrombotic events. Thus, the management of thrombotic complications occurring in haemophilic patients should be discussed in each case according to the precipitating risk factors, the clinical context and the thrombo-haemorrhagic balance of the patient with respect to a particular clinical situation.

Optimizing the management of HER2-negative metastatic breast cancer with capecitabine (Xeloda)

Patients with metastatic breast cancer (MBC) require chemotherapy that improves outcomes without compromising quality of life. To achieve optimal outcomes with chemotherapy, treatment choices should be influenced by patient and disease characteristics, as well as patient preferences. Capecitabine (Xeloda; F. Hoffmann-La Roche, Basel, Switzerland) combined with docetaxel achieves significantly superior response rates, time to progression, and overall survival compared with single-agent docetaxel. With a manageable safety profile, capecitabine/docetaxel is a particularly appropriate option for younger, fitter patients with rapidly progressing disease and/or visceral metastases. In addition, studies show that dosing flexibility with capecitabine/docetaxel allows management of side effects without compromising efficacy. However, for older patients and those with comorbidities or more indolent disease, single-agent capecitabine may be more appropriate. Studies show that front-line capecitabine is a highly effective and well-tolerated alternative to standard intravenous treatments. The activity of capecitabine in the first-line treatment of MBC is underpinned by its consistently high activity in MBC. As an oral agent that causes minimal alopecia and myelosuppression, capecitabine has the potential to significantly improve patient quality of life and convenience. In summary, the treatment of MBC will always need to be individualized, but a large body of evidence indicates that capecitabine, whether alone or in combination, can be offered to women early in the disease course.

Future options with capecitabine (Xeloda) in (neo)adjuvant treatment of breast cancer

As an active and well-tolerated agent in the treatment of metastatic breast cancer, capecitabine (Xeloda, F. Hoffmann-La Roche, Basel, Switzerland) has the potential to confer significant clinical benefits in the primary treatment of breast cancer. The minimal myelosuppression and alopecia associated with capecitabine, together with its potential for synergistic activity with a range of other anticancer therapies, lend support to its use in combination regimens with other commonly used cytotoxic agents. Trials to date show that capecitabine combinations incorporating taxanes, vinorelbine, anthracyclines, and cisplatin are active and well tolerated in the metastatic setting. To more fully explore the clinical utility of capecitabine in early breast cancer, an extensive, worldwide phase II/III program is evaluating capecitabine as a component of adjuvant and neoadjuvant therapy. Results presented to date of the large adjuvant and neoadjuvant trials incorporating capecitabine are encouraging and suggest that women with breast cancer might benefit from the activity of capecitabine early in the disease course.

Upper-extremity deep vein thrombosis: a prospective registry of 592 patients

BACKGROUND

Upper-extremity deep vein thrombosis (UEDVT) occurs spontaneously or sometimes develops as a complication of pacemaker use, long-term use of a central venous catheter (CVC), or cancer.

METHODS AND RESULTS

To improve our understanding of UEDVT, we compared the demographics, symptoms, risk factors, prophylaxis, and initial management of 324 (6%) patients with central venous catheter (CVC)-associated UEDVT, 268 (5%) patients with non-CVC-associated UEDVT, and 4796 (89%) patients with lower-extremity DVT from a prospective US multicenter DVT registry. The non-CVC-associated UEDVT patients were younger (59.2+/-18.2 versus 64.2+/-16.9 years old; P<0.0001), less often white (65% versus 73%; P<0.01), leaner (body mass index [BMI] 26.8+/-7.1 versus 28.5+/-7.3 kg/m2; P<0.001), and more likely to smoke (19% versus 13%; P=0.02) than the lower-extremity DVT patients. By way of propensity analysis and multivariable logistic regression analysis, we determined that an indwelling CVC was the strongest independent predictor of UEDVT (odds ratio [OR], 7.3; 95% confidence interval [CI], 5.8 to 9.2). An age of <67 years, a BMI of <25 kg/m2, and hospitalization were the independent predictors of non-CVC-associated UEDVT. Most (68%) UEDVT patients were evaluated while they were inpatients. Only 20% of the 378 UEDVT patients who did not have an obvious contraindication to anticoagulation received prophylaxis at the time of diagnosis.

CONCLUSIONS

UEDVT risk factors differ from the conventional risk factors for lower-extremity DVT. Our findings identify deficiencies in our current understanding and the prophylaxis of UEDVT and generate hypotheses for future research efforts.

Antithrombotic Therapy in Children*

This article about antithrombotic therapy in children is part of the 7th American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh the risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this article are the following. In neonates with venous thromboembolism (VTE), we suggest treatment with either unfractionated heparin or low-molecular-weight heparin (LMWH), or radiographic monitoring and anticoagulation therapy if extension occurs (Grade 2C). We suggest that clinicians not use thrombolytic therapy for treating VTE in neonates, unless there is major vessel occlusion that is causing the critical compromise of organs or limbs (Grade 2C). For children (ie, > 2 months of age) with an initial VTE, we recommend treatment with i.v. heparin or LMWH (Grade 1C+). We suggest continuing anticoagulant therapy for idiopathic thromboembolic events (TEs) for at least 6 months using vitamin K antagonists (target international normalized ratio [INR], 2.5; INR range, 2.0 to 3.0) or alternatively LMWH (Grade 2C). We suggest that clinicians not use thrombolytic therapy routinely for VTE in children (Grade 2C). For neonates and children requiring cardiac catheterization (CC) via an artery, we recommend i.v. heparin prophylaxis (Grade 1A). We suggest the use of heparin doses of 100 to 150 U/kg as a bolus and that further doses may be required in prolonged procedures (both Grade 2 B). For prophylaxis for CC, we recommend against aspirin therapy (Grade 1B). For neonates and children with peripheral arterial catheters in situ, we recommend the administration of low-dose heparin through a catheter, preferably by continuous infusion to prolong the catheter patency (Grade 1A). For children with a peripheral arterial catheter-related TE, we suggest the immediate removal of the catheter (Grade 2C). For prevention of aortic thrombosis secondary to the use of umbilical artery catheters in neonates, we suggest low-dose heparin infusion (1 to 5 U/h) (Grade 2A). In children with Kawasaki disease, we recommend therapy with aspirin in high doses initially (80 to 100 mg/kg/d during the acute phase, for up to 14 days) and then in lower doses (3 to 5 mg/kg/d for > or = 7 weeks) [Grade 1C+], as well as therapy with i.v. gammaglobulin within 10 days of the onset of symptoms (Grade 1A).

Prophylaxis of venous thromboembolism in medical patients

PURPOSE OF REVIEW

Venous thromboembolism is a multifactorial silent disease and tends not to be suspected by physicians, especially in medical patients. Pulmonary embolism is the most preventable cause of death among hospitalized patients. It is of major importance to assess the risk for venous thromboembolism and to adapt the prophylactic strategy with the aim of improving the risk-benefit ratio of the prophylaxis.

RECENT FINDINGS

Prophylaxis of venous thromboembolism can be done by either mechanical means or pharmacologic agents or both. The Medenox trial, the Prime study, the Prince study, the Prevent study, and the Artemis trial demonstrated that acutely ill medical patients are at increased risk of venous thromboembolism and that low molecular weight heparins (enoxaparin 40 mg or dalteparin 5000 IU subcutaneously once daily for 10 days) as well as fondaparinux 2,5 mg subcutaneously once daily for 10 days have a favorable risk-benefit ratio in the prevention of venous thromboembolism in acutely ill medical patients. The publication of the results of the Exclaim study is expected to clarify the optimal duration of prophylaxis in this group of patients. Patients hospitalized in medical intensive care units as well as patients with active cancer or central venous catheters are at increased risk of venous thromboembolism, and the studies published so far demonstrate the favorable risk-benefit ratio of thromboprophylaxis with either low molecular weight heparins or low-dose warfarin.

SUMMARY

Acutely ill medical patients are at increased risk of venous thromboembolism. Prophylaxis with low molecular weight heparins and fondaparinux is effective and safe. Initiatives to improve venous thromboembolism prophylaxis should be based on the education of physicians regarding the individualized risk assessment.

Antithrombotic therapy and cancer

PURPOSE OF THE REVIEW

To assess the current evidence from recent clinical trials investigating antithrombotic agents for the prophylaxis and treatment of venous thromboembolism in cancer patients and for the effects of these agents on cancer progression.

RECENT FINDINGS

A growing body of evidence supports the preventive use of antithrombotic strategies in subgroups of cancer patients. Moreover, in the long-term management of deep venous thrombosis in cancer patients, low-molecular-weight heparin seems to represent a valid alternative to vitamin K antagonists. Finally, several studies have claimed a direct anticancer activity and a positive impact on prognosis of some antithrombotic agents, eg, aspirin and low-molecular-weight heparin.

SUMMARY

Although recent evidence suggests low-molecular-weight heparin as a possible option in the management and prevention of venous thromboembolism in cancer patients, more evidence from large randomized, prospective, controlled trials is needed to determine the exact the magnitude of the risk-benefit ratio associated with its use. The promising results on the effects of antithrombotic agents in the prognosis of cancer patients deserve further evaluation to estimate the potential and the feasibility of this approach.