Low molecular weight heparin for Hickman catheter--induced thrombosis in thrombocytopenic patients undergoing bone marrow transplantation

Venous thromboembolism in hematopoietic stem cell transplantation: A narrative review

Venous thromboembolism (VTE) is a common complication of hematopoietic stem cell transplantation (HSCT) and its treatment has significant effects on morbidity and non-relapse mortality. There is a complex interplay on balancing the risk for thrombosis and bleeding in these patients, making treatment decisions particularly challenging. Despite this, there are currently no validated risk assessment models or guidelines to aid clinical decision making on thromboprophylaxis and VTE treatment in this population of patients. Herein, we review the many risk factors for VTE in HSCT patients, categorized into patient, disease, catheter, treatment, laboratory, and transplant-related variables. This review also discusses current thromboprophylaxis and VTE management strategies in HSCT patients, with scope into the development of risk assessment models that allow for identification of high-risk subgroups who may benefit from targeted intervention.

PICC-related upper deep venous thrombosis in patients with hematological malignancies. Management of anticoagulant therapy according to the platelet count

Peripherally inserted central catheters (PICCs) for central venous access are frequently used in patients with hematological malignancies. Their use may be complicated by upper extremity deep venous thrombosis (UEDVT). Additionally, hematological patients are frequently thrombocytopenic and the optimal management of UEDVT in patients with thrombocytopenia is challenging and poorly standardized. We retrospectively analyzed 50 adult patients affected by hematological malignancies who presented a PICC-associated UEDVT. UEDVT treatment was compared in 3 groups: patients with a platelet count ≥ 50 × 10⁹/l (group1) who underwent a therapeutic dose of low molecular weight heparin (LMWH) or fondaparinux 7.5 mg; patients with a platelet count < 50 × 10⁹/l and ≥ 30 × 10⁹/l (group 2) who were treated with a 50% reduced dose of LMWH or fondaparinux 5 mg; patients with platelets < 30 × 10⁹/l (group 3) were observed and treated with anticoagulants when the count was > 30 × 10⁹//l. At the onset of thrombosis, 36 patients were in group 1, 8 in group 2 and 6 in group 3. We observed no hemorrhagic or thrombotic complications related to the anticoagulant therapy; length of treatment was comparable between groups 1 and 2 (51 days group 1 vs 50 days group 2). Reduced doses of LMWH or fondaparinux may represent a safe and effective therapeutic approach in patients with moderate thrombocytopenia (< 50 × 10⁹/l and ≥ 30 × 10⁹/l) and a PICC-associated UEDVT.

Platelet cut-off for anticoagulant therapy in thrombocytopenic patients with blood cancer and venous thromboembolism: an expert consensus

BACKGROUND

Management of venous thromboembolism (VTE) in patients with haematologic malignancies and thrombocytopenia is clinically challenging due to the related risks. No prospective studies or clinical trials have been carried out and, therefore, no solid evidence on this compelling issue is available.

METHODS

Given this, an expert panel endorsed by the Gruppo Italiano Malattie Ematologiche dell'Adulto Working Party on Thrombosis and Haemostasis was set up to produce a formal consensus, according to the RAND method, in order to issue clinical recommendations about the platelet (PLT) cut-off for safe administration of low molecular weight heparin (LMWH) in thrombocytopenic (PLT <100×109/L) adult patients with haematologic malignancies affected by acute (<1 month) or non-acute VTE.

RESULTS

In acute VTE, the panel suggests safe anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L and at 50% dose reduction for PLT ≥30<50×109/L. In acute VTE for PLT <30×109/L, the following interventions are recommended: positioning of an inferior vena cava (IVC) filter with prophylactic LMWH administration and platelet transfusion. In non-acute VTE, anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L or over and at 50% dose reduction for PLT ≥30<50×109/L is considered appropriate. The discontinuation of full or reduced therapeutic dose of LMWH is recommended for PLT <30×109/L, both in acute and non-acute VTE.

DISCUSSION

We suggest using dose-adjusted LMWH according to PLT to optimise anticoagulant treatment in patients at high bleeding risk.

Treatment of venous thromboembolism in acute leukemia: A systematic review

BACKGROUND

The safety and efficacy of venous thromboembolism (VTE) treatment in patients with acute leukemia (AL) are not well understood and the optimal treatment strategy is unclear.

METHODS

We conducted a systematic review of the literature aiming to identify observational studies and randomized trials describing treatment of VTE in the setting of AL including, acute myeloid leukemia (AML), acute promyelocytic leukemia (APL), and acute lymphoblastic leukemia (ALL). Due to the heterogeneity of findings, no meta-analysis was attempted.

RESULTS

A total of 13 observational studies (11 cohorts and 2 case-control) totaling 5359 participants were included. The number of patients with VTE among the total population was 304 (5.7%; 95% CI 5.1-6.3). In patients with VTE, 221 patients received treatment with anticoagulation using either of low-molecular-weight heparin, unfractionated heparin, and/or vitamin K antagonists. Most studies adjusted the anticoagulant dose based on platelet count. The reported recurrence rate ranged from 0 to 29% among different studies and varied according to the duration of anticoagulant treatment and follow up. Bleeding events were not uniformly reported but the total number was low among anti-coagulated patients.

CONCLUSION

There is a significant lack of data in this area with a high degree of heterogeneity in the choice of anticoagulant, dose adjustments for thrombocytopenia, and duration of anticoagulation. Further studies are required to develop guidelines and suggestions for treatment of VTE in AL.

Management of anticoagulation for cancer-associated thrombosis in patients with thrombocytopenia: A systematic review

BACKGROUND

The management of anticoagulation for cancer-associated thrombosis (CAT) in patients with thrombocytopenia is controversial. Whereas some studies suggest that administration of reduced-dose low-molecular-weight heparin (LMWH) or temporary discontinuation for moderate and severe thrombocytopenia may be a safe and effective, others suggest full-dose anticoagulation with transfusion support. We sought to address this important knowledge gap and summarize the literature comparing these two common management strategies.

METHODS

A systematic review of the literature (PROSPERO CRD42017077127) using MEDLINE (inception to September 2017) was conducted. We included studies that reported recurrent venous thromboembolism (VTE) and major bleeding complications among patients treated with both of the two most common management strategies: therapeutic anticoagulation with platelet transfusion support and dose-modified anticoagulation for periods when the platelet count is <50 × 109/L.

RESULTS

A total of 134 article records were identified on the initial search and 10 articles underwent full text review. Two observational studies met the inclusions criteria. A total of 121 patients with CAT and thrombocytopenia were included. Forty-two of these patients had pulmonary embolism and 87 had deep vein thrombosis (DVT) including 38 upper extremity DVT. Overall, 27% of patients, regardless of their treatment strategy, experienced recurrent VTE. Thirteen percent of anticoagulated patients (15% of all patients) experienced a major bleeding episode. Meta-analysis could not be conducted.

CONCLUSIONS

Our findings do not support one management strategy over another to treat CAT patients with thrombocytopenia. However, the data highlights the heightened risk of recurrent VTE in this patient population despite the thrombocytopenia.

Advanced stage breast cancer is associated with catheter-tip thrombus formation following implantable central venous port placement

PURPOSE

Catheter-tip associated thrombosis is not uncommon in patients with implantable central venous ports; however, the prevalence and clinical impact of this complication on patient management is unclear. This study aims to identify risk factors for thrombus formation in a large population receiving serial echocardiograms (echo) following port placement.

METHODS

A total of 396 female breast cancer patients underwent internal jugular vein chest port placement between 2007 and 2013 and received echo studies every third month. Catheter tip position was measured from chest radiography and catheter associated thrombus was identified by echo.

RESULTS

Sixteen out of 396 patients (4%) had catheter-tip thrombus. No patients were symptomatic or prophylactically anticoagulated. Patients with thrombus were significantly younger than those without (46.4 years versus 53.4 years, respectively, p = 0.02) and had higher stage breast cancer with 75% versus 44.7% having stage III or IV cancer ( p = 0.017). Thrombus was identified after a median of 91 days. No significant difference was identified in anatomic ( p = 0.1) or measured ( p = 0.15) tip position, port laterality ( p = 0.86), or number of port lumens ( p = 0.65).

CONCLUSIONS

In this large cohort, younger patients and those with more advanced stage breast cancer were more associated with catheter-tip-related thrombus after port placement.

Safety and Efficacy of Enoxaparin Treatment in Venous Thromboembolic Disease during Acute Leukemia

Background

Venous thromboembolism (VTE) is a quite common complication in acute leukemia, although its real incidence is unknown. The best treatment of this complication is still a matter of debate due to the very high risk of hemorrhage in this group of patients.

Patients and methods

From December 2000 to December 2002 four Caucasian patients with acute leukemia developed VTE complications. The patients were three men and one woman, mean age 55.7 years (range, 27-77). Two patients with acute lymphoid leukemia (L1 and L2 according to the FAB classification) developed deep venous thrombosis during the administration of chemotherapy; one patient with acute myeloid leukemia (AML, M2 according to the FAB classification) had pulmonary thromboembolism at diagnosis, while another AML patient (M4 according to FAB) showed deep venous thrombosis as the first symptom of leukemia. The clinical diagnosis of symptomatic VTE was confirmed by objective imaging procedures including lower limb venous color Doppler imaging in all cases and a ventilation-perfusion lung scan in one case. All patients were treated with enoxaparin 100 IU/kg subcutaneously twice daily for one month, followed by 150 IU/kg once daily for at least five months. When the platelet count was below 20,000 × 109/L, the dose was reduced by 50%.

Results

During antithrombotic treatment neither VTE recurrences nor hemorrhagic complications or heparin-induced thrombocytopenia occurred. The platelet count at the beginning of enoxaparin treatment was very low (mean, 55,750 × 109/L; range, 12,000-121,000 × 109/L) and treatment did not affect platelet recovery.

Conclusions

Enoxaparin proved to be efficacious and safe in the management of deep venous thrombosis with or without pulmonary embolism in patients affected by acute leukemia. Enoxaparin cured acute venous thrombosis, prevented recurrences and did not cause any hemorrhagic complications despite prolonged severe thrombocytopenia.

Thrombosis in cancer patients: etiology, incidence, and management

Venous thromboembolism (VTE) is the second most common cause of mortality in cancer patients. The mechanisms of cancer-associated thrombosis (CAT), much like cancer itself, are multi-factorial and incompletely understood. Cancer type, stage, tumor-derived factors and genetics all affect CAT risk. Furthermore, cancer therapies as well as the indwelling vascular devices through which these therapies are delivered can increase the risk for CAT. In this review, we summarize mechanisms of hypercoagulability in cancer patients, patterns of thrombosis associated with cancer, current guidelines for the diagnosis and management of CAT, and important considerations regarding the placement of implantable vascular devices in the care of cancer patients with VTE.

Management of venous thromboembolism during thrombocytopenia after autologous hematopoietic cell transplantation

Management of venous thromboembolism (VTE) remains challenging in patients with hematologic malignancy who undergo hematopoietic cell transplantation (HCT) due to prolonged thrombocytopenia. This study aims to (1) determine the incidence of VTE recurrence and bleeding during autologous HCT, (2) assess the impact of continuing vs temporarily withholding anticoagulation during thrombocytopenia, and (3) explore the impact of platelet threshold among other variables on the risk of bleeding. We performed this observational study in adults with lymphoma and myeloma who underwent autologous HCT between 2006 and 2015. We selected patients with index VTE prior to HCT and assigned them to different cohorts based on antithrombotic management at the onset of thrombocytopenia. Primary outcomes included VTE recurrence and major bleeding by 30 days after HCT. Secondary outcomes included platelet and red blood cell transfusions, time to engraftment, and overall survival. Of the 1631 patients who underwent autologous HCT, 204 patients (12.5%) had preceding index VTE events, and among them, 132 patients continued and 72 patients temporarily withheld anticoagulation during thrombocytopenia. There were no significant differences in VTE recurrence (1.5% vs 1.4%) or major bleeding (3.8% vs 4.2%) between 2 groups by 30 days. The number of platelet transfusions was significantly higher in the first group. Baseline elevated bilirubin, creatinine, and prothrombin time were independently associated with increased risk in major bleeding, whereas neither platelet threshold nor average platelet count was predictive. Our findings suggest that for many patients undergoing autologous HCT, temporarily withholding anticoagulation during thrombocytopenia may offer the best risk-benefit tradeoff among available options.

Analysis of anticoagulation strategies for venous thromboembolism during severe thrombocytopenia in patients with hematologic malignancies: a retrospective cohort

The safety and efficacy of anticoagulation for venous thromboembolism (VTE) at times of severe thrombocytopenia is unclear. In this retrospective study, we evaluated patients with hematologic malignancy and either (1) acute or chronic VTE on anticoagulation before platelet count dropped below 50 × 10⁹/L or (2) acute VTE occurring while platelets were <50 × 10⁹/L. In 78 eligible patients, the primary outcomes of time to recurrent VTE or clinically significant bleeding within 100 d were compared by management strategy. Bleeding occurred in 27% of patients receiving anticoagulation versus 3% when anticoagulation was held (IRR 10.1, 95% CI 1.5-432.6). Recurrent VTE occurred in 2% of patients receiving anticoagulation versus 15% when anticoagulation was held (IRR 0.17, 95% CI 0.0-1.51). Most bleeding occurred before day 31(11/13), but recurrent VTE mostly occurred after day 40 (5/6). Our findings suggest that temporarily withholding anticoagulation for VTE during severe thrombocytopenia in patients with hematologic malignancies might reduce adverse outcomes.

Venous thromboembolism in patients with hematologic malignancy and thrombocytopenia

The optimal management of hematologic malignancy-associated venous thromboembolism (VTE) in patients with moderate-to-severe thrombocytopenia is unclear. This is a retrospective study of 128 adult patients with hematologic malignancies who were diagnosed with VTE. The outcome of patients with significant thrombocytopenia (≤50,000/µL) was compared with those without. Forty-seven patients (36.7%) had a platelet count ≤50,000/µL during a period of time of perceived need for new or continued anticoagulation. The median nadir platelet count in those with significant thrombocytopenia was 10,000/µL (range 2,000-45,000/µL) versus 165,000/µL (50,000-429,000/µL) in those without (P < 0.001). The median duration of significant thrombocytopenia in the first group was 10 days (1-35 days). Therapy during the period of significant thrombocytopenia included prophylactic-dose low-molecular-weight heparin (LMWH) (47%), therapeutic-dose LMWH or heparin (30%), warfarin (2%), inferior vena cava filter (2%), and observation (17%). Patients without thrombocytopenia were managed with the standard of care therapy. At a median follow-up of more than 2 years, the risk of clinically significant bleeding (11% vs 6%, P = 0.22) including major bleeding (6% vs 2%) and clot progression or recurrence (21% vs 22%, P = 1.00) were similar in patients with or without significant thrombocytopenia. In a multivariate analysis, the risk of recurrence/progression (hazard ratio, HR 0.59, 95% CI 0.21-1.66, P = 0.31) and hemorrhage rate (HR 0.29, 95% CI 0.05-1.56, P = 0.15) did not differ based on the presence of significant thrombocytopenia. Within the limits of this retrospective study, cautious use of prophylactic-dose LMWH may be safe in thrombocytopenic patients with hematologic malignancy-associated VTE. Am. J. Hematol. 91:E468-E472, 2016. © 2016 Wiley Periodicals, Inc.

Guideline on aspects of cancer-related venous thrombosis

The guideline was drafted by a writing group identified by the Haemostasis and Thrombosis Task Force of the British Committee for Standards in Haematology (BCSH). All the authors are consultants in haematology in the UK. A search was performed of PubMed and Embase using the term 'cancer' combined with 'thrombosis', 'treatment', 'prophylaxis' and 'clinical presentation'. The search covered articles published up until December 2014. Only human studies were included and articles not written in English were excluded. References in recent reviews were also examined. The writing group produced the draft guideline, which was subsequently revised by consensus by members of the Haemostasis and Thrombosis Task Force of the BCSH and the BCSH executive. The guideline was then reviewed by the sounding board of the British Society for Haematology (BSH). This comprises 50 or more members of the BSH who have reviewed the guidance and commented on the content and application to the UK setting. The 'GRADE' system was used to quote levels and grades of evidence, details of which can be found at: http://www.bcshguidelines.com/BCSH_PROCESS/EVIDENCE_LEVELS_AND_GRADES_OF_RECOMMENDATION/43_GRADE.html. The objective of this guideline is to provide healthcare professionals with clear guidance on the prevention and management of venous thromboembolism (VTE) in patients with cancer and to advise on an approach to screening for cancer in patients with unprovoked VTE in whom cancer was not initially suspected based on clinical grounds.

Medical management of tumor lysis syndrome, postprocedural pain, and venous thromboembolism following interventional radiology procedures

The rapid expansion of minimally invasive image-guided procedures has led to their extensive use in the interdisciplinary management of patients with vascular, hepatobiliary, genitourinary, and oncologic diseases. Given the increased availability and breadth of these procedures, it is important for physicians to be aware of common complications and their management. In this article, the authors describe management of select common complications from interventional radiology procedures including tumor lysis syndrome, acute on chronic postprocedural pain, and venous thromboembolism. These complications are discussed in detail and their medical management is outlined according to generally accepted practice and evidence from the literature.

Anticoagulant therapy for venous thromboembolism detected by Doppler ultrasound in patients with metastatic colorectal cancer receiving bevacizumab

BACKGROUND

Doppler ultrasound imaging is useful for management of venous thromboembolism associated with a subclavicular implantable central venous access system in patients receiving bevacizumab (Bev). We investigated the efficacy and safety of our anticoagulant regimen based on Doppler findings.

METHODS

Patients aged ≤75 years with metastatic colorectal cancer, no history of thromboembolism, and no prior use of Bev received chemotherapy plus Bev. Doppler ultrasound imaging of the deep venous system to detect thrombosis was performed after the first course of Bev and repeated after the third course in patients with asymptomatic thrombosis. Indications for anticoagulant therapy in patients with asymptomatic thrombosis were as follows: enlarging thrombus (E), thrombus >40 mm in diameter (S), thrombus involving the superior vena cava (C), and decreased blood flow (V).

RESULTS

Among 79 patients enrolled in this study, asymptomatic thrombosis was detected in 56 patients (70.9%) by Doppler ultrasound imaging after the first course of Bev and there was no thrombus in 23 patients (29.1%). Of these 56 patients, 11 (19.6%) received anticoagulant therapy with warfarin, including eight after the first course and three after follow-up imaging. S + V was observed in four of 11 patients (36.4%), as well as V in two (18.2%), S + V + C in one (9.1%), E + S + V in one (9.1%), E + C in one (9.1%), E in one (9.1%), and C in one (9.1%). All patients resumed chemotherapy, including seven who resumed Bev. Improvement or stabilization of thrombi was achieved in ten patients (90.9%). Only one patient had symptomatic thromboembolism. Mild bleeding due to anticoagulant therapy occurred in six patients (54.5%), but there were no treatment-related severe adverse events or deaths. Severe thromboembolism was not observed in the other 68 patients.

CONCLUSION

Our anticoagulant protocol for asymptomatic thrombosis detected by Doppler ultrasound imaging was effective at preventing severe thromboembolism during continued treatment with Bev.

Advances and directions in chemotherapy using implantable port systems for colorectal cancer: a historical review

With the recent advances in chemotherapy for colorectal cancer, the prognosis for patients with metastatic colorectal cancer has been significantly improved. The development of the implantable port system has also enabled patients to receive multiagent chemotherapy with a more satisfactory quality of life. Historically, chemotherapy using implantable port systems was begun to obtain an oncological benefit in the treatment of locoregional cancer. In the 1950s, there was an increasing interest in perfusion techniques for the application of chemotherapeutic agents, such as nitrogen mustard, in the locoregional treatment of metastatic cancer. Among them, the treatment of liver metastasis has interested oncologists for many years. On the other hand, implantable devices were developed during the intervening decades that have enabled patients with colorectal cancer with liver metastases to be treated effectively using hepatic arterial infusion; which became more common in the 1980s. The treatment of metastatic colorectal cancer increasingly requires a multimodal approach and multiple treatment options based not on convenience, but in terms of personalization and efficacy. Therefore, it is important to optimize the pharmacokinetics of chemotherapeutic agents. Implantable port systems for colorectal cancer patients have been essential for oncological practice, and the importance of these systems will remain unchanged in the near future.

Antithrombotic Therapy in Patients With Thrombocytopenic Cancer

Background:

Guidelines are discordant concerning management of patients having thrombocytopenia with cancer-associated thrombosis (CAT).

Methods:

Hospitalized adults with CAT and platelets ≤50 × 109 cells/L were managed with dalteparin 100 units/kg subcutaneously once daily. Comparator patients with CAT and platelets >50 × 109 cells/L were managed with dalteparin 200 units/kg/d.

Results:

Outcomes of 35 patients with thrombocytopenia (mean platelet count 26 ± 8.3 × 109 cells/L) and 58 comparator patients (mean platelet count 155 ± 75 × 109 cells/L) were evaluated. In all, 2 (5.7%) patients in the thrombocytopenia group and 1 patient (1.9%) in the comparator group experienced new-onset venous thromboembolism (odds ratio 3.31, 95% confidence interval [CI] 0.29-37.90, P = .556). The incidence of bleeding in patients with thrombocytopenia (8.6%) was similar to that in comparator patients (9.4%; risk ratio 0.94, 95% CI 0.37-2.39, P = .607).

Conclusion:

In hospitalized patients having thrombocytopenia with CAT, reduced-dose low-molecular-weight heparin was generally efficacious.

Treatment of cancer-associated thrombosis

Therapeutic options for the management of venous thromboembolism (VTE) in patients with cancer remain very limited. Although low-molecular-weight heparin monotherapy has been identified as a simple and efficacious regimen compared with an initial parenteral anticoagulant followed by long-term therapy with a vitamin K antagonist, many clinical questions remain unanswered. These include optimal duration of anticoagulant therapy, treatment of recurrent VTE, and the treatment of patients with concurrent bleeding or those with a high risk of bleeding. Treatment recommendations from consensus clinical guidelines are largely based on retrospective reports or extrapolated data from the noncancer population with VTE, as randomized controlled trials focused on cancer-associated thrombosis are sorely lacking. Furthermore, with improvements in imaging technology and extended survival duration of patients with cancer, we are encountering more unique challenges, such as the management of incidental VTE. Clinicians should be aware of the limitations of the novel oral anticoagulants and avoid the use of these agents because of the paucity of evidence in the treatment of cancer-associated thrombosis.

Thrombotic obstruction of the central venous catheter in patients undergoing hematopoietic stem cell transplantation

This is an integrative literature review with the aim of summarizing the prevention measures and treatment of thrombotic obstruction of long-term semi-implanted central venous catheters, in patients undergoing hematopoietic stem cell transplantation. The sample consisted of seven studies, being two randomized controlled clinical trials, three cohort studies and two case series. Regarding the prevention measures, one single study demonstrated effectiveness, which was a cohort study on the oral use of warfarin. In relation to the treatment measures, three studies evidenced effectiveness, one highlighted the efficacy of streptokinase or urokinase, one demonstrated the benefit of using low-molecular-weight heparin and the other treated the obstruction with heparin or urokinase. Catheter patency research shows a restricted evolution that does not follow the evolution of transplantations, mainly regarding nursing care.

Central venous catheter-related right atrial thrombus in two kidney transplantation recipients

Right atrial thrombus formation is a known mechanical complication of central venous catheter insertion, with an incidence of between 1.9% and 42%. There is an increased risk of thromboembolism following renal transplantation. However, a right atrial thrombosis is rarely reported in renal transplant recipients. Here, we report two cases of renal transplant recipients in whom a right atrial thrombus developed after kidney transplantation. One of them required surgery, whereas the other patient recovered after being given an anticoagulant therapy with warfarin.

Malignancy and venous thrombosis in the critical care patient

Venous thromboembolic disease has significant clinical consequences. There are few data available to guide its management in the critically ill cancer patient, perhaps the most complex and challenging patient population encountered. Multiple interacting and often unique factors contribute to both the thrombotic and bleeding risk in such patients. Anticoagulants are effective for prophylaxis and treatment; heparins are the best-studied agents in this setting. Whether unfractionated or low-molecular-weight heparin is the most appropriate agent depends on the exact clinical situation. Prevention of venous thrombosis is a well-recognized health priority, but thromboprophylaxis remains underused, especially in some high-risk populations such as cancer patients. Enhanced recognition of the thrombotic risk factors and a better understanding of the risks and benefits of anticoagulant therapy are necessary to improve utilization, and much research is needed to address how to implement effective thromboprophylaxis strategies. Careful consideration of the patient's overall prognosis is necessary to develop safe, effective, and individualized approaches to treating thrombosis.

Management of venous thromboembolism in colorectal cancer patients treated with bevacizumab

Venous thromboembolism associated with use of a central venous access system is an urgent problem in patients treated with bevacizumab (bev). We investigated the effectiveness of Doppler ultrasound imaging (DUS) in the early detection of catheter-related thrombosis for avoidance of severe venous thromboembolism. Patients with metastatic colorectal cancer received either FOLFOX-4 + bev or FOLFIRI + bev. DUS was performed on the deep venous system for detection of thrombus formation during the initial cycle of treatment, followed by re-evaluation after the third cycle in patients with asymptomatic thrombus formation. All patients were followed up until treatment was interrupted. Median duration of follow-up was 484 days (range 72-574). Among 41 enrolled patients, curable symptomatic thrombosis occurred in one, and asymptomatic thrombosis in 21 (51.2%). Of 21 patients undergoing re-evaluation, thrombi remained without progression in 17 patients, and enlargement in 4 patients. In two of the patients in whom there was progression, pulmonary embolism occurred after the sixth cycle. In the asymptomatic group, no thrombi developed as far as the superior vena cava in any patient. In the cases of progression, thrombotic enlargement was observed in all the 4 patients, with decreased vascular flow in 2. Using DUS, we were able to detect asymptomatic thrombosis in the early cycles of treatment, indicating its potential in the monitoring of venous thrombi. In the event of an enlarging asymptomatic thrombosis developing into the superior vena cava along with decreased vascular flow, careful follow-up and appropriate anticoagulant therapy may be recommended without increased risk of bleeding.

Enoxaparin can be Used Safely in Patients with Severe Thrombocytopenia due to Intensive Chemotherapy Regimens

Treatment with intensive chemotherapy regimens is frequently complicated by severe thrombocytopenia. During the period of severe thrombocytopenia, anticoagulant treatment is not uncommonly indicated for thromboembolic events or thromboprophylaxis in these patients. We report 10 hematological patients treated with intensive chemotherapy protocols that were anticoagulated with enoxaparin for catheter related central venous thrombosis and thromboprophylaxis. During the period of severe thrombocytopenia the dosages of enoxaparin were reduced and no major bleeding occurred. Based on our experience we suggest that reduced dosages of low molecular weight heparins may be used relatively safely during transient severe thrombocytopenia.

Thrombotic and infectious complications of central venous catheters in patients with hematological malignancies

Central venous catheters (CVCs) have considerably improved the management of patients with hematological malignancies, by facilitating chemotherapy, supportive therapy and blood sampling. Complications of insertion of CVCs include mechanical (arterial puncture, pneumothorax), thrombotic and infectious complications. CVC-related thrombosis and infections are frequently occurring complications and may cause significant morbidity in patients with hematological malignancies. CVC-related thrombosis and infections are related and can therefore not be seen as separate entities. The incidence of symptomatic CVC-related thrombosis had been reported to vary between 1.2 and 13.0% of patients with hematological malignancy. The incidence of CVC-related bloodstream infections varies between 0.0 and 20.8%. There is need for a specific approach regarding diagnosis and treatment of CVC-related thrombosis and infection with specific attention to the preservation of the catheter. Since data on CVC-related infections and thrombosis in hematological patients have been obtained mainly from retrospective studies of small sample size, prospective, randomized studies of prophylactic measures concerning CVC-related thrombosis and infection are warranted.

Management of venous port systems in oncology: a review of current evidence

BACKGROUND

Over the last decades, many changes have occurred in oncology with new chemotherapy combinations and more complex application schemes becoming available. Central venous catheters and implantable venous port systems have become widely used and have facilitated the problem of vascular access. However, important complications are associated with permanent central venous catheters.

MATERIAL AND METHODS

This review summarizes evidence on venous port system use published in Medline up to February 2007. Moreover, recent guidelines for the prevention and management of catheter-related infections issued by the Infectious Diseases Society of America, the American College of Critical Care Medicine, the Society for Healthcare Epidemiology of America, the Center for Disease Control and Prevention, Atlanta, and the Infectious Diseases Working Party of the German Society of Hematology and Oncology are included.

RESULTS

Sterile precautions are essential when implanting and accessing port systems. Infections must be treated with adequate antimicrobial therapy. Catheter-related thromboembolic complications were found at a rate of 12-64% in retrospective studies. Five current clinical trials investigated the effect of prophylactic anticoagulation with either low molecular weight heparin or warfarin in cancer patients with central venous devices. On the basis of these results, routine anticoagulation cannot be recommended.

CONCLUSIONS

This article reviews the current literature on long-term complications of venous port systems, focusing on infection and thrombosis. In addition, it summarizes the evidence regarding routine maintenance of port systems in follow-up care.

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.

Randomized placebo-controlled study of low-dose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer

PURPOSE

In this multicenter, randomized, placebo-controlled clinical trial, we studied whether warfarin 1 mg daily reduces the incidence of symptomatic central venous catheter (CVC) -associated thrombosis in patients with cancer.

PATIENTS AND METHODS

Two hundred fifty-five patients with cancer who required a CVC for at least 7 days were randomly assigned to receive warfarin 1 mg or placebo.

RESULTS

There were 11 (4.3%) symptomatic CVC-associated thromboses among 255 patients, with no difference in the incidence of symptomatic CVC-associated thrombosis between patients taking warfarin 1 mg daily (six of 130 patients; 4.6%) and patients taking placebo (five of 125 patients; 4.0%; hazard ratio, 1.20; 95% CI, 0.37 to 3.94). Warfarin had no effect on CVC life span (84 days v 63 days in control and warfarin groups, respectively; 95% confidence limit, -16 to 55 days; P = .09), and it did not affect the number of premature CVC removals (23.2% v 25.4% in control and warfarin groups, respectively; 95% confidence limit of difference -8.34 to 12.71; P = .68) or the frequency of major bleeding episodes (2% v 0% in control and warfarin groups, respectively; P = .5, Fisher's exact test).

CONCLUSION

Symptomatic CVC-associated thrombosis in patients with cancer, although significant, is less common than previously reported. In this study, the administration of warfarin 1 mg daily did not reduce the incidence of symptomatic CVC-associated thrombosis in patients with cancer. However, the low rate of symptomatic CVC-associated thrombosis means that a much larger trial is required to address this issue definitively.

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

Long-term central venous catheters (CVCs) have considerably improved the management of cancer patients because they facilitate chemotherapy, transfusions, parenteral nutrition, and blood sampling. However, the use of long-term CVCs, especially for chemotherapy, has been associated with the occurrence of upper-limb deep venous thrombosis (UL-DVT). The incidence of clinically overt UL-DVT related to CVCs has been reported to vary between 0.3% and 28.3%. The incidence of CVC-related UL-DVT screened by venography reportedly varies between 27% and 66%. The incidence of clinically overt pulmonary embolism (PE) in patients with CVC-related UL-DVT ranges from 15% to 25%, but an autopsy-proven PE rate of up to 50% has been reported. Vessel injury caused by the procedure of CVC insertion, venous stasis caused by the indwelling CVC, and cancer-related hypercoagulability are the main pathogenetic factors for CVC-related venous thromboembolism (VTE). Several studies have assessed the benefit of the prophylaxis of UL-DVT after CVC insertion in cancer patients. According to the results of these studies, prophylaxis with low molecular weight heparin or a low fixed dose of warfarin has been recently proposed. However, the limitations of the experimental design of the prophylactic studies do not allow definitive recommendations. The recommended therapy for UL-DVT associated with CVC is based on anticoagulant therapy with or without catheter removal. This review focuses on the epidemiology, pathogenesis, diagnosis, prevention, and treatment of VTE in cancer patients with long-term CVC.

Acute pulmonary thromboembolism induced by prophylactic heparin use and a heparin-coated catheter: a case of heparin-induced thrombocytopenia and thrombosis syndrome

Heparin-induced thrombocytopenia and thrombosis syndrome (HITTS) is a potentially life-threatening side effect of heparin therapy, triggered by an immune response, and has been reported to be related not only to the therapeutic use of heparin but also to heparin-coated catheters. A 45-year-old woman with intrapelvic malignancy developed an acute pulmonary thromboembolism (PE) after hysterectomy despite prophylactic heparin use. Subsequent large doses of heparin for treatment of the PE exacerbated the thrombocytopenia and, moreover, a large thrombus formed around the heparin-coated central venous catheter. Anti-heparin-platelet factor 4 complex antibody and heparin-induced platelet aggregation assay were positive, so the diagnosis was HITTS, and heparin was replaced by argatroban after carrying out thrombectomy. This therapy was successful, and the patient made favorable progress.

Massive right atrial thrombosis due to Hickman catheter requiring open heart surgery--a case report

The risk of catheter-related sepsis and clot formation in patients with an indwelling central venous line is well recognized. However the risk of developing a large thrombus in the right atrium is less well known. Right atrial thrombus can be a life-threatening complication of long-term indwelling catheters and should be considered in the workup of these patients. A case of a 71-year-old lady who developed a large atrial thrombus due to a Hickman catheter is reported that required open heart surgery. Incidence, pathophysiology, clinical presentation, diagnosis, and treatment options are also reviewed.

No effect of nadroparin prophylaxis in the prevention of central venous catheter (CVC)-associated thrombosis in bone marrow transplant recipients

Complications of CVCs in 382 consecutive patients receiving a stem cell transplantation (SCT) were analysed. Early complications were pneumothorax (3.6%), haematothorax (0.5%), dislocation (3%) and dysfunction (3.6%). Eighty-seven-associated infections (22%) were observed, leading to removal of the CVC in 26 patients. More bacteraemias were associated with double- or triple-lumen CVCs, 19% vs 5% in single lumen CVCs (P < 0.0001). Coagulase-negative staphylococci were the predominant microorganisms in 72%. A special point of investigation was CVC-associated thrombosis and the prophylactic value of nadroparin. Two consecutive regimens with nadroparin were used and compared; 7 days 2850 IE nadroparin and 10 days 5700 IE nadroparin. The incidence of CVC-associated thrombosis was 6.9% in 382 patients with 390 catheters. The incidence was 8% in patients receiving one of the prophylactic nadroparin regimens compared to 6% in a comparable control group without prophylaxis. A short course of nadroparin was unable to prevent thrombotic complications after discontinuation.

Chylothorax and chylopericardium: a complication of a central venous catheter

This article describes a rare and severe complication of central venous catheterization, namely extensive thrombosis within the venous system of the chest resulting in bilateral chylothorax and chylopericardium. The complication resolved with drainage, catheter removal, and low molecular weight heparin therapy.

Right atrial thrombi are related to indwelling central venous catheter position: insights into time course and possible mechanism of formation

We studied the effect of central line catheters on thrombus formation in the right atrium (RA), including the incidence and echocardiographic characteristics of the catheter-associated thrombus as well as possible clinical implications in patients. We prospectively studied 55 patients by transesophageal echocardiography within 1 week after Hickman catheter implantation and on a follow-up study at 6 to 8 weeks. We succeeded in imaging the catheter tip in 48 of the 55 patients (87%). In the baseline study 13 had the tip placed in the RA, eight at the superior vena cava-atrium junction, and 27 in the superior vena cava. An abnormal mass, consistent with a thrombus, was found in 12.5% of the patients, all of which were seen within the 13-patient (46%) group with the Hickman catheter tip placed in the RA. Hickman catheter insertion is associated with high incidence (12.5%) of early formation of RA thrombus. The formation of these thrombi is asymptomatic and highly associated (p < 0.001) with the catheter tip position in the RA, in contrast to their positioning in the superior vena cava or in its junction with the right atrium. On the basis of these findings, we recommend that special attention and effort be given to placing of the catheter tip in the superior vena cava and avoiding the RA during the implantation procedure.

A review of 560 Hickman catheter insertions

Indwelling, cuffed, tunnelled, central venous (Hickman) catheters are increasingly being used for venous access and the administration of chemotherapy for oncological patients. This paper reviews the technical problems associated with the percutaneous insertion of these catheters and the complications arising from their use. Five hundred and sixty catheters were inserted; 31.3% had complications at insertion, most commonly precipitation of an arrhythmia (13.9%). Arterial puncture occurred in 3.8% and pneumothorax in 1.6%. Catheters remained in place for a median period of 91 days. Forty percent of catheters were removed electively on completion of treatment; 30.2% required removal because of complications, which included sepsis, migration, thrombosis and blockage. Twenty percent of patients died with their catheter in place, 8.5% were still in situ and 1.6% were removed because of patient non compliance. Sepsis remains the commonest, long term complication, with staphylococcus epidermidis being the organism isolated most frequently. There were no catheter-related deaths.

Thrombosis and hemorrhage in oncology patients

As outlined in this review, patients with cancer may harbor many alterations of hemostasis. These are multifaceted and must be considered when trying to control hemorrhage or thrombosis in cancer patients. Also, hemorrhage or thrombosis is often the final fatal event in many patients with metastatic solid tumor or hematologic malignancies. Patients with malignancy present a major clinical challenge in this new era of oncologic awareness and more aggressive care, which has led to prolonged survival for patients and a longer time frame during which these complications may develop. Therefore, these complications are occurring more commonly. It is important to realize that these alterations of hemostasis exist and must be approached in a sequential and logical manner with respect to diagnosis; only in this way can responsible, efficacious, and rational therapy be delivered to patients. By far the most common alteration of hemostasis in malignancy is that of hemorrhage associated with thrombocytopenia, either drug-induced, or radiation-induced, or from bone marrow invasion. Hemorrhage resulting from DIC, however, is also quite common and may present as hemorrhage, thrombosis, thromboembolus, or any combination thereof. Many antineoplastic drugs and radiation therapy may lead to or significantly enhance hemorrhage in patients with malignancy. Thrombosis, also commonly seen in patients with malignancy, is often a manifestation of low-grade DIC. When approaching the patient with malignancy and either hemorrhage or thrombosis, all the potential defects in hemostasis must be considered, defined from the laboratory standpoint, and treated in as precise and logical manner as possible.

Low molecular weight heparin for the prevention of veno-occlusive disease of the liver in bone marrow transplantation patients

Hepatic veno-occlusive disease (VOD), a common complication of bone marrow transplantation (BMT), is a result of intensive conditioning by chemo-radiotherapy. Endometrial injury causes fibrin deposition in the affected hepatic venules, leading to abnormal laboratory parameters followed by lethal full-blown disease. Previous studies have shown that unfractionated heparin can prevent VOD in BMT patients. Since low molecular weight heparin (LMWH) preserves the antithrombotic, but not the anticoagulant, activity of unfractionated heparin, we initiated a pilot study to determine the safety of LMWH for the prevention of VOD. Sixty-one patients undergoing BMT (allogeneic, n=24; autologous, n=37) were randomized to receive subcutaneous injection of enoxaparin (40 mg/day x 1) or a placebo prior to BMT conditioning and until day 40 after transplantation or discharge from the hospital. LMWH administration did not influence marrow engraftment, nor was it associated with bleeding tendency. Hemorrhagic events occurred significantly less frequently (P=0.025) were shorter duration (P=0.006) in the LMWH group than in the placebo group. Time to platelet recovery was significantly shorter (16.5 vs 29.6 days, (P=0.0075), and platelet transfusion requirements were lower (p=0.05) in the LMWH patients. VOD parameters occurred less frequently in the experimental group, including duration of elevated bilirubin levels (P=0.01) and incidence of hepatomegaly (P=0.04). LMWH, which seems to enhance platelet recovery, may be safely administrated to BMT patients in an attempt to prevent VOD of the liver.

Administration of chemotherapeutic agents. Techniques and controversies

Safe and pain-free vascular access is now the achievable goal for every patient receiving systemic chemotherapy. The discomfort and anxiety that used to accompany multiple (often unsuccessful) venipunctures can be avoided by placement of a long-term central-venous-access device as part of the patient's early treatment plan. In the United States, approximately 5 x 10(5) such devices are now inserted each year. This review discusses and compares the different types of devices currently available, methods of insertion, and management of morbidity. Future studies should focus on the cost effectiveness of these devices, better selection of patients for the various types of access, and avoidance, recognition, and treatment of complications.