Prophylaxis of central venous catheter-related thrombosis with minidose warfarin in patients treated with high-dose chemotherapy and peripheral-blood stem-cell transplantation: retrospective analysis of 228 cancer patients

Acute phase after haematopoietic stem cell transplantation

The transplantation of allogeneic or autologous haematopoietic stem cells is an established treatment for many malignant and non-malignant diseases of the bone marrow. Intensive cytoreductive regimens administered before transplantation induce prolonged and severe cytopenia of all haematopoietic lineages. Thrombocytopenia leads to an increased risk of bleeding, which may be further aggravated by consumption of plasmatic factors as a result of tumour lysis or after antibody administration. At the same time, patients after transplantation are also at increased risk of thrombotic complications. Endothelial damage induced by radio-and chemotherapy, indwelling catheters, prolonged immobilization and a high incidence of systemic infection all contribute to the frequent occurrence of thromboembolic events in this population.

This review discusses the incidence and risk factors for haemorrhagic and thrombotic complications after stem cell transplantation. Special emphasis is given to complications occurring specifically in the context of transplantation such as diffuse alveolar haemorrhage, haemorrhagic cystitis, veno-occlusive disease, and transplant associated microangiopathy.

Systemic Anticoagulant Prophylaxis for Central Catheter–Associated Venous Thrombosis in Cancer Patients

Objective:

To review the literature regarding the incidence of thrombosis in cancer patients with central venous catheters (CVCs) and weigh the evidence supporting thromboprophylaxis in this patient population.

Data Sources:

Clinical literature was identified by searching MEDLINE (1966–February 2007) using the key search terms malignancy, cancer, catheters, prophylaxis, thrombosis, and central venous catheters.

Study Selection and Data Extraction:

An evaluation of retrospective and prospective clinical trials that studied the use of systemic anticoagulants (eg, warfarin, heparin, and low-molecular-weight heparin [LMWH]) to prevent thrombosis with CVCs was performed. Different patient populations, including those manifesting with solid tumor or hematologic malignancy and those undergoing hematopoietic stem cell transplant, were evaluated for this review.

Data Synthesis:

Thrombosis associated with CVCs is a common complication in cancer patients. Most CVC thrombosis will occur within 30 days after placement, with a majority within 8 days. The incidence may depend on the type of CVC and location of the catheter tip. Despite recommendations against the use of systemic anticoagulation for prophylaxis against CVC thrombosis, a potential role continues to be explored in selected settings. Several variables are noted between published clinical trials, making any comparisons difficult to determine whether any benefit exists. Generally, the use of mini-dose warfarin, LMWH, or low-dose unfractionated heparin did not consistently reach significance in reporting a reduction in CVC thrombosis.

Conclusions:

Available data do not support the routine use of anticoagulants for thromboprophylaxis to prevent CVC-related thrombosis. However, several inconsistencies can be found in the studies done to date. More studies are needed to identify subsets of cancer patients who are at higher risk of developing CVC thrombosis and may benefit from prophylactic systemic anticoagulation.

Early and late complications related to central venous catheters in hematological malignancies: a retrospective analysis of 1102 patients

Several severe complications may be associated with the use of central venous catheters (CVC). We retrospectively evaluated on a large cohort of patients the incidence of CVC-related early and late complications. From 7/99 to 12/2005, 1102 CVC have been implanted at our Institution in 881 patients with hematological malignancies (142,202 total day number of implanted CVC). Early mechanic complications were 79 (7.2% - 0.55/1,000 days/CVC). Thirty-nine episodes of early infective complications (<1 week from CVC implant) occurred (3.5% - 0.3/1000 days/CVC): furthermore, 187 episodes of CVC-related sepsis (17% - 1.3/1000 days/CVC) were recorded. There were 29 episodes (2.6%) of symptomatic CVC-related thrombotic complications, with a median interval from CVC implant of 60 days (range 7 – 395). The rate of CVC withdrawal due to CVC-related complications was 26%. The incidence of CVC-related complications in our series is in the range reported in the literature notwithstanding cytopenia often coexisting in hematological patients.

Incidence and risk factors for central venous catheter-related thrombosis in hematological patients

Catheter-related thrombosis (CRT) is a serious complication in hematological patients, but the risk factors for its occurrence are not well established. The study objectives were to estimate the incidence of CRT and to identify the risk factors for developing CRT in hematological patients. In a prospective setting, 104 consecutive patients with 200 insertions of central venous catheters were enrolled into the study. The patients were screened for CRT by compression Doppler ultrasound every 10–14 days. Additionally, ultrasonography was performed in the case of clinical symptoms suggesting CRT. Over the course of 6,098 catheter days of follow-up, the incidence of CRT was 13.5 %. In 18/27 cases (66.6 %), radiological evidence of CRT was preceded by clinical symptoms. However, in 9/27 (33.3 %), CRT was clinically asymptomatic. The median times to symptomatic and asymptomatic CRT were 17 (range 1–49) and 8 (range 1–16) catheter days, respectively. In univariate analysis, the risk factors for CRT were exit-site infection (ESI) (P < 0.001), two or more prior chemotherapy lines (P = 0.015), catheter-related blood stream infection (P < 0.001), and Coagulase-negative staphylococci infection (P = 0.002). In multivariate analysis, ESI (OR 5.0; 95 % CI 1.6–6.3; P = 0.006) and two or more prior chemotherapy lines (OR 3.57; 95 % CI 1.27–10.11; P = 0.015) remained significantly associated with the risk of CRT. The results of our study provide information regarding the characteristic features of the patients who are at high risk of thrombosis, for whom Doppler ultrasound screening should be considered.

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.

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.

Prevention of central venous catheter-associated thrombosis: a meta-analysis

PURPOSE

Anticoagulant prophylaxis in patients with central venous catheters is controversial. We performed a meta-analysis of randomized controlled trials of anticoagulant prophylaxis in patients with central venous catheters.

METHODS

MEDLINE and EMBASE were searched up to May 2006, supplemented by manual searches of conference proceedings and bibliographies.

RESULTS

Fifteen trials were included. Unfractionated heparin infusion, oral fixed low-dose vitamin K antagonist, and subcutaneous low-molecular-weight heparin were evaluated. For all catheter-associated deep vein thrombosis (symptomatic and asymptomatic combined), the summary relative risks ranged from 0.31 to 0.73 (all achieved statistical significance). For symptomatic deep vein thrombosis, the summary relative risks ranged from 0.28 to 0.72, but did not achieve statistical significance for any individual regimen.

CONCLUSION

Anticoagulant prophylaxis is effective for preventing all catheter-associated deep vein thrombosis in patients with central venous catheters. The effectiveness for preventing symptomatic venous thromboembolism, including pulmonary embolism, remains uncertain.

Prevention of catheter-related venous thrombosis with nadroparin in patients receiving chemotherapy for hematologic malignancies: a randomized, placebo-controlled study

BACKGROUND

Hemato-oncology patients treated with intensive chemotherapy usually require the placement of a central venous catheter (CVC). CVCs are frequently complicated by catheter-related central venous thrombosis (CVT), which has been associated with an increased risk of pulmonary embolism and catheter-related infection.

OBJECTIVES

To determine the efficacy and safety of thromboprophylaxis with s.c. low-molecular-weight heparin (nadroparin) administered once daily in a randomized placebo-controlled, double-blind trial in patients with hematologic malignancies.

PATIENTS AND METHODS

Consecutive patients with hematologic malignancies requiring intensive chemotherapy including autologous stem cell transplantation were eligible. The patients were randomized to receive nadroparin 2850 antifactor Xa units once daily or placebo s.c. for 3 weeks. Venography was performed on day 21 after CVC insertion. Secondary outcomes were bleeding and catheter-related infection.

RESULTS

In total, 113 patients were randomized to nadroparin or placebo, and 87 patients (77%) underwent venography. In total, 11 venographically proven catheter-related CVTs were diagnosed. The frequency of catheter-related CVT was not significantly different between study groups, namely four catheter-related CVTs in the placebo group [9%; 95% CI: 0.002-0.16] vs. seven catheter-related CVTs in the nadroparin group (17%; 95% CI: 0.06-0.28). In addition, no difference in the incidence of catheter-related infection or bleeding was observed between the groups.

CONCLUSION

This study showed that the actual risk for catheter-related CVT in patients with hematologic malignancies is lower than suggested in earlier studies in cancer patients. Although prophylactic administration of nadroparin appeared to be safe in this group of patients with a high risk of bleeding, it cannot be recommended for the prevention of catheter-related CVT or catheter-related infection in patients with hematologic malignancies.