The diagnostic value of colour Doppler ultrasound in central venous catheter related thrombosis

[Translation into French and republication of: "Central venous catheter associated upper extremity deep vein thrombosis in cancer patients: Diagnosis and therapeutic management"]

Catheter-related thrombosis (CRT) is a relatively frequent and potentially fatal complication arising in patients with cancer who require a central catheter placement for intravenous treatment. In everyday practice, CRT remains a challenge for management; despite its frequency and its negative clinical impact, few data are available concerning diagnosis and treatment of CRT. In particular, no diagnostic studies or clinical trials have been published that included exclusively patients with cancer and a central venous catheter (CVC). For this reason, many questions regarding optimal management of CRT remain unanswered. Due to the paucity of high-grade evidence regarding CRT in cancer patients, guidelines are derived from upper extremity DVT studies for diagnosis, and from those for lower limb DVT for treatment. This article addresses the issues of diagnosis and management of CRT through a review of the available literature and makes a number of proposals based on the available evidence. In symptomatic patients, venous ultrasound is the most appropriate choice for first-line diagnostic imaging of CRT because it is noninvasive, and its diagnostic performance is high (which is not the case in asymptomatic patients). In the absence of direct comparative clinical trials, we suggest treating patients with CRT with a therapeutic dose of either a LMWH or a direct oral factor Xa inhibitor, with or without a loading dose. These anticoagulants should be given for a total of at least 3 months, including at least 1 month after catheter removal following initiation of therapy.

Systematic review of the use of ultrasound for venous assessment and venous thrombosis screening in spaceflight

The validity of venous ultrasound (V-US) for the diagnosis of deep vein thrombosis (DVT) during spaceflight is unknown and difficult to establish in diagnostic accuracy and diagnostic management studies in this context. We performed a systematic review of the use of V-US in the upper-body venous system in spaceflight to identify microgravity-related changes and the effect of venous interventions to reverse them, and to assess appropriateness of spaceflight V-US with terrestrial standards. An appropriateness tool was developed following expert panel discussions and review of terrestrial diagnostic studies, including criteria relevant to crew experience, in-flight equipment, assessment sites, ultrasound modalities, and DVT diagnosis. Microgravity-related findings reported as an increase in internal jugular vein (IJV) cross-sectional area and pressure were associated with reduced, stagnant, and retrograde flow. Changes were on average responsive to venous interventions using lower body negative pressure, Bracelets, Valsalva and Mueller manoeuvres, and contralateral IJV compression. In comparison with terrestrial standards, spaceflight V-US did not meet all appropriateness criteria. In DVT studies (n = 3), a single thrombosis was reported and only ultrasound modality criterion met the standards. In the other studies (n = 15), all the criteria were appropriate except crew experience criterion, which was appropriate in only four studies. Future practice and research should account for microgravity-related changes, evaluate individual effect of venous interventions, and adopt Earth-based V-US standards.

Central venous catheter associated upper extremity deep vein thrombosis in cancer patients: Diagnosis and therapeutic management

Catheter-related thrombosis (CRT) is a relatively frequent and potentially fatal complication arising in patients with cancer who require a central catheter placement for intravenous treatment. In everyday practice, CRT remains a challenge for management; despite its frequency and its negative clinical impact, few data are available concerning diagnosis and treatment of CRT. In particular, no diagnostic studies or clinical trials have been published that included exclusively patients with cancer and a central venous catheter (CVC). For this reason, many questions regarding optimal management of CRT remain unanswered. Due to the paucity of high-grade evidence regarding CRT in cancer patients, guidelines are derived from upper extremity DVT studies for diagnosis, and from those for lower limb DVT for treatment. This article addresses the issues of diagnosis and management of CRT through a review of the available literature and makes a number of proposals based on the available evidence. In symptomatic patients, venous ultrasound is the most appropriate choice for first-line diagnostic imaging of CRT because it is noninvasive, and its diagnostic performance is high (which is not the case in asymptomatic patients). In the absence of direct comparative clinical trials, we suggest treating patients with CRT with a therapeutic dose of either a LMWH or a direct oral factor Xa inhibitor, with or without a loading dose. These anticoagulants should be given for a total of at least three months, including at least one month after catheter removal following initiation of therapy.

Role of Doppler ultrasonography in the evaluation of hemodialysis arteriovenous access maturation and influencing factors

The goal of vascular access creation is to achieve a functioning arteriovenous fistula (AVF) or arteriovenous graft (AVG). An autologous fistula has been shown to be superior to AVG or to central venous catheters (CVCs) with lowest rate of re-intervention, but vessel obstruction or immaturity accounts for 20 % to 54% of cases with primary failure of AVF. This review is focused on the factors influencing maturation; indication and timing of preoperative mapping/creation of vascular access; ultrasound parameters for creation AVF/AVG; early postoperative complications following creation of a vascular access; ultrasound determinants of fistula maturation and endovascular intervention in vascular access with maturation failure. However, vascular accesses that fail to develop, have a high incidence of correctable abnormalities, and these need to be promptly recognized by ultrasonography and managed effectively if a high success rate is to be expected. We review approaches to promoting fistula maturation and duplex ultrasonography (DUS) of evaluating vascular access maturation.

Diagnosis of deep vein thrombosis of the upper extremity: a systematic review and meta-analysis of test accuracy

Upper extremity deep vein thrombosis (UEDVT) accounts for ≤10% of DVT and can be associated with morbidity and mortality. Accurate diagnosis and treatment are necessary for safe and effective patient management. We systematically reviewed the accuracy of D-dimer and duplex ultrasonography (US) for the evaluation of suspected first-episode UEDVT. We searched the Cochrane Central Register, OVID MEDLINE, EMBASE, and PubMed for eligible studies, reference lists of relevant reviews, registered trials, and relevant conference proceedings. We included prospective cross-sectional and cohort studies that evaluated test accuracy. Two investigators independently screened and collected data. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies 2 and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework. We pooled estimates of sensitivity and specificity. The review included 9 studies. The pooled estimates for D-dimer sensitivity and specificity were 0.96 (95% confidence interval [CI], 0.87-0.99) and 0.47 (95% CI, 0.43-0.52), respectively. The pooled estimates for duplex US sensitivity and specificity were 0.87 (95% CI, 0.73-0.94) and 0.85 (95% CI, 0.72-0.93), respectively. Certainty of evidence was moderate. In this review, we summarized the test accuracy (sensitivity and specificity) of D-dimer and duplex US for this indication. The sensitivity and specificity of the tests found in the present review should be considered in the context of whether they are used alone or in combination, which is dependent on the prevalence of disease in the population, the clinical setting in which the patient is being evaluated, cost, potential harms, and patient outcomes. This study was registered at PROSPERO as Systematic Review Registration Number CRD42018098488.

Early prophylaxis of central venous catheter-related thrombosis using 1% chlorhexidine gluconate and chlorhexidine-gel-impregnated dressings: a retrospective cohort study

To determine the prophylactic effect of using combined 1% alcoholic chlorhexidine gluconate and chlorhexidine gel-impregnated dressings (CGCD) on catheter-related thrombosis (CRT) in critically ill patients. This retrospective cohort study was performed in an intensive care unit from November 2009 to August 2014. The CRT incidence diagnosed with ultrasound examination was compared between patients applying CGCD and combined 10% aqueous povidone-iodine and standard transparent dressings (PITD) after central venous catheter insertion into the internal jugular vein for ≥ 48 h. CRT was stratified into early (within 7 days) and late (days 8-14) thromboses. Multivariate analyses using logistic regression models clarified the relationships between early- and late-CRT risks and skin antiseptic and catheter site dressing combinations. CRT occurred in 74 of 134 patients (55%), including 52 with early CRT and 22 with late CRT. Patients receiving CGCD had a significantly lower incidence of early CRT than those receiving PITD (odds ratio = 0.18; 95% confidence interval = 0.07-0.45, p  < .001). No significant association was evident between using CGCD and late CRT (p  = .514). Compared to PITD, CGCD reduced the CRT risk over 7 days in critically ill patients.UMIN Clinical Trials Registry: UMIN000037492.

ACR Appropriateness Criteria® Suspected Upper Extremity Deep Vein Thrombosis

This publication includes the appropriate imaging modalities to assess suspected deep vein thrombosis in the upper extremities. Ultrasound duplex Doppler is the most appropriate imaging modality to assess upper-extremity deep vein thrombosis. It is a noninvasive test, which can be performed at the bedside and used for serial evaluations. Ultrasound can also directly identify thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure. It can indirectly identify thrombus from altered blood-flow patterns. It is most appropriate in the evaluation of veins peripheral to the brachiocephalic vein. CT venography and MR venography are not first-line imaging tests, but are appropriate to assess the central venous structures, or to assess the full range of venous structures from the hand to the right atrium. Catheter venography is appropriate if therapy is required. Radionuclide venography and chest radiography are usually not appropriate to assess upper-extremity deep vein thrombosis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: diagnosis of venous thromboembolism

BACKGROUND

Modern diagnostic strategies for venous thromboembolism (VTE) incorporate pretest probability (PTP; prevalence) assessment. The ability of diagnostic tests to correctly identify or exclude VTE is influenced by VTE prevalence and test accuracy characteristics.

OBJECTIVE

These evidence-based guidelines are intended to support patients, clinicians, and health care professionals in VTE diagnosis. Diagnostic strategies were evaluated for pulmonary embolism (PE), deep vein thrombosis (DVT) of the lower and upper extremity, and recurrent VTE.

METHODS

The American Society of Hematology (ASH) formed a multidisciplinary panel including patient representatives. The McMaster University GRADE Centre completed systematic reviews up to 1 October 2017. The panel prioritized questions and outcomes and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations. Test accuracy estimates and VTE population prevalence were used to model expected outcomes in diagnostic pathways. Where modeling was not feasible, management and accuracy studies were used to formulate recommendations.

RESULTS

Ten recommendations are presented, by PTP for patients with suspected PE and lower extremity DVT, and for recurrent VTE and upper extremity DVT.

CONCLUSIONS

For patients at low (unlikely) VTE risk, using D-dimer as the initial test reduces the need for diagnostic imaging. For patients at high (likely) VTE risk, imaging is warranted. For PE diagnosis, ventilation-perfusion scanning and computed tomography pulmonary angiography are the most validated tests, whereas lower or upper extremity DVT diagnosis uses ultrasonography. Research is needed on new diagnostic modalities and to validate clinical decision rules for patients with suspected recurrent VTE.

Hemodialysis Catheter-Related Central Venous Thrombosis: Clinical Approach to Evaluation and Management

Central venous catheter (CVC) use is common among patients undergoing hemodialysis. Catheter-related vascular thrombosis is a frequent complication, which results in catheter dysfunction. This may eliminate the affected vein as a potential route of vascular access and leads to significant morbidity of the limbs involved. Despite increasing prevalence, there is a dearth of evidence-based guidelines for managing such catheter-related thrombi, often leading to treatment dilemmas in clinical practice. Minimizing the use of CVCs for hemodialysis remains the best approach in preventing such adverse complications. Furthermore, meticulous planning and care when using such catheters in unavoidable circumstances along with vigilant surveillance to identify complications early will allow to avoid associated morbidity.

Factors causing loss of normal Doppler waveform of the left internal jugular vein: evaluation on chest computed tomography

PURPOSE

To evaluate the presence and causes of left brachiocephalic vein (LBCV) steno-occlusive lesions in patients with loss of normal waveform in Doppler ultrasound of the left internal jugular vein (LIJV).

MATERIALS AND METHODS

We performed Doppler ultrasound of both internal jugular veins in 1912 patients who received an implantable venous access port from August 2013 to January 2016. Among them, 106 patients showed loss of normal Doppler waveforms of the LIJV (56 men and 50 women; mean age, 61.4 ± 11.6 years). We retrospectively analyzed the presence and causes of the LBCV steno-occlusive lesions on contrast-enhanced chest computed tomography (CT) images.

RESULTS

LBCV steno-occlusive lesions were present in 82 patients (77.4%). The causes of these lesions were anatomic structures (n = 70, 85.4%), tumorous lesions (n = 11, 13.4%), and thrombus (n = 1, 1.2%). The anterior anatomic structures to the LBCV causing stenosis were bony structures (n = 50), right upper lobe (n = 11), and mediastinal fat (n = 9). The posterior anatomic structures to the LBCV resulting in stenosis were right brachiocephalic artery (n = 58), left common carotid artery (n = 7), and aortic arch (n = 5). The tumorous lesions resulting in stenosis were mediastinal lymph node (n = 5), thymic lesions (n = 3), lymphoma (n = 1), lung cancer (n = 1), and bone tumor (n = 1).

CONCLUSIONS

It is necessary to suspect steno-occlusive lesion of the LBCV from various causes and to use caution when performing central venous catheterization in cases with loss of a normal Doppler waveform.

INFLUENCE OF LONG-TERM CYTOTOXIC CHEMOTHERAPY ON THE CONDITION OF PERIPHERAL VENOUS CHANNEL

The necessity of long-term venous access in cancer patients appears at frequent and long-term courses of cytotoxic therapy. Peripheral veins of forearms are most often used for these aims. The conditions of peripheral venous channel in 32 cancer patients, who underwent the long-term treatment with antitumor preparations were analyzed in the article on own investigatory material. The methods of dopplerography, morphological and immunohystochemical studies were used. The qualitative and quantitative dopplerographic changes in forearm veins in different terms after chemotherapy start were revealed in most patients. The conclusion was made about unsuitability of forearm peripheral veins for the long term administration of cytostatics and the necessity to create the alternative vascular access that would correspond to the criteria of safety, reliability and long-term exploitation.

Prospective monitoring of cytomegalovirus, Epstein-Barr virus, BK virus, and JC virus infections on belatacept therapy after a kidney transplant

OBJECTIVES

Few data regarding viral replication in patients receiving belatacept are available. The aim of this single-center study was to compare the incidence of viral infections (cytomegalovirus, Epstein Barr virus, BK virus, and JC virus), in 62 de novo kidney transplant patients enrolled in the BENEFIT studies, receiving either belatacept (n=42) or cyclosporine (n=20).

MATERIALS AND METHODS

By means of polymerase chain reaction, belatacept-treated patients were tested for cytomegalovirus, Epstein-Barr virus, BK virus, and JC virus infections monthly for 36 months, monthly for the first 6 months, and then quarterly for 36 months in cyclosporine-treated patients. Additional samples were obtained when a viral infection was suspected.

RESULTS

The number of positive cytomegalovirus, BK virus, or JC virus viremias over the number of polymerase chain reactions performed through all 3 years was similar in both groups. Conversely, over the 3-year study, the number of positive Epstein-Barr virus viremias over the number of Epstein-Barr virus polymerase chain reactions performed was significantly higher in the belatacept group (76% vs 50%; P = .047). The number of Epstein-Barr virus primary infection was similar in both groups, while the number of Epstein-Barr virus reactivation was higher in the belatacept group.

CONCLUSIONS

Epstein-Barr virus replication occurs more often in patients receiving belatacept, than it does in those receiving cyclosporine.

Risk factors for subclavian vein thrombosis in cancer patients with total parenteral nutrition

Background

There are few reports on total parenteral nutrition (TPN) and its possible prothrombotic effect. The purpose of this study was to identify risk factors for subclavian vein thrombosis (SVT) in patients receiving TPN.

Method

Cancer patients with indwelling subclavian catheters and TPN were followed in a cohort study. Doppler ultrasound examination was performed 8 and 30 days after catheter placement.

Results

One hundred twenty-one patients were included, with a mean of 61 (± 11.8) years of age. We detected 36 SVT events at day 8 (29.8%) and 47 (38.8%) at day 30 after central catheter placement. Mean length of subclavian catheterization was 17.2 (± 8.2) days. Fifty-three point three percent of patients receiving ≥ 3,050 mOsm TPN in 24 hours developed SVT (relative risk (RR) = 2.01, 95% CI, 1.14 - 3.57; P = 0.016) at day 8 and 60% (RR = 1.67, 95% CI, 1.30 - 2.71; P = 0.038) at day 30 post-catheter placement. Protein administration of > 97.5 g/day was shown to be a risk factor for early thrombosis with a mean of 16.88 days for the development of SVT (95% CI, 10 - 23.7) versus 27.8 days (95% CI, 25.8 - 29.9) in the group with nutritional protein content < 97.5 g/day (P = 0.000).

Conclusion

High-osmolarity and high-protein nutrition formulas were shown to be risk factors for SVT in cancer patients receiving TPN.

Central venous thrombosis and thrombophilia in cystic fibrosis: A prospective study

BACKGROUND AND AIMS

Catheter venous thrombosis may result in life-threatening embolic complications. Recently, a thrombophilic tendency was described in cystic fibrosis (CF), the significance of which remains unclear. The aims of this study were to (1) document the frequency of catheter venous thrombosis detected by colour-Doppler-ultrasound (Doppler-US), (2) assess genetic and acquired thrombophilia risk factors for catheter venous thrombosis and hypercoagulability status and (3) provide recommendations on laboratory screening when considering insertion of a totally implantable vascular access device (TIVAD) in CF patients.

METHODS

We designed a multicentre prospective study in patients selected at the time of catheter insertion. Doppler-US was scheduled at 1 and 6months after insertion and before insertion in case of a previous central line. Blood samplings were drawn at insertion and at 1 and 6months later.

RESULTS

One-hundred patients received a TIVAD and 90 completed the 6-month study. Prevalence of thrombophilia abnormalities and hypercoagulability was found in 50% of the cohorts. Conversely, catheter venous thrombosis frequency was low (6.6%).

CONCLUSION

Our data do not support biological screening at the time of a TIVAD insertion. We emphasise the contribution of a medical history of venous thromboembolism and prospective Doppler-US for identifying asymptomatic catheter venous thrombosis to select patients who may benefit from biological screening and possible anticoagulant therapy.

Venous access catheter-related thrombosis in patients with cancer

Patients with cancer are at high risk for developing venous thromboembolism (VTE), and the presence of a central venous catheter (CVC) further increases this risk. CVC-related VTE has serious implications related to the loss of vascular access, development of pulmonary embolism, recurrent VTE, infections and post-thrombotic syndrome. The pathogenesis of CVC-related VTE is complex and multifactorial, with risk factors associated with the catheter, the vessel selected for insertion and the underlying cancer as well as the anti-cancer therapy. Clinical presentation of CVC-related VTEs is often non-specific, and ultrasonography is the most commonly used radiological diagnostic test. Management of CVC-related VTE in patients with cancer requires a balance between the need for venous access, the risk of VTE recurrence and the risk of bleeding from treatment-induced thrombocytopenia. Effective VTE prophylaxis methods have yet to be defined. Ongoing studies are evaluating the role of newer oral antithrombotic agents and alternative interventional strategies for the prevention and treatment of CVC-related VTE in patients with cancer.

Effort thrombosis presenting as pulmonary embolism in a professional baseball pitcher

Context:

Effort thrombosis, or Paget-Schroetter’s syndrome, is a rare subset of thoracic outlet syndrome in which deep venous thrombosis of the upper extremity occurs as the result of repetitive overhead motion. It is occasionally associated with pulmonary embolism. This case of effort thrombosis and pulmonary embolus was in a 25-year-old major league professional baseball pitcher, in which the only presenting complaints involved dizziness and shortness of breath without complaints involving the upper extremity—usually, a hallmark of most cases of this condition. The patient successfully returned to play for 5 subsequent seasons at the major league level after multimodal treatment that included surgery for thoracic outlet syndrome.

Objective:

Though rare, effort thrombosis should be included in the differential diagnosis of throwing athletes with traditional extremity-focused symptoms and in cases involving pulmonary or thoracic complaints. Rapid diagnosis is a critical component of successful treatment.

Assessment of internal jugular vein thrombosis due to central venous catheter in hemodialysis patients: a retrospective and prospective serial evaluation with ultrasonography

AIM

We aimed to evaluate the frequency of catheter-related internal jugular vein (IJV) thrombosis, associated factors, and the anatomical variations of IJV in hemodialysis patients.

MATERIAL AND METHODS

Hemodialysis patients were evaluated with B-mode ultrasonography (USG). Participants in the prospective group were evaluated using USG prior to catheter insertion, 10 days after catheter insertion, at the time of catheter removal, and 15 days after removal.

RESULTS

The rate of thrombosis was increased correlated with the number of catheter insertions. These rates were 14%, 15%, and 47% in those undergoing catheter insertion once, twice, and three times, respectively (P < .05). The anatomical variations of IJV were 21% in the retrospective cases. No significant relationship was found between anatomical variations and thrombosis and between some biochemical parameters and thrombosis.

CONCLUSION

Catheter-related IJV thrombosis is frequent in hemodialysis patients. Long catheter remaining time and repeated catheterization increase the thrombosis rate.

Multimodality imaging of the peripheral venous system

The purpose of this article is to review the spectrum of image-based diagnostic tools used in the investigation of suspected deep vein thrombosis (DVT). Summary of the experience gained by the author as well as relevant publications, regarding vein imaging modalities taken from a computerized database, was reviewed. The imaging modalities reviewed include phlebography, color Doppler duplex ultrasonography (CDDUS), computerized tomography angiography (CTA) and venography (CTV), magnetic resonance venography (MRV), and radionuclide venography (RNV). CDDUS is recommended as the modality of choice for the diagnosis of DVT. A strategy combining clinical score and D-dimer test refines the selection of patients. Phlebography is reserved for discrepant noninvasive studies.

Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings

BACKGROUND

Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD).

PURPOSE

To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter-related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports.

MATERIAL AND METHODS

Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis.

RESULTS

Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report.

CONCLUSION

CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi.

Thrombotic events after pediatric liver transplantation

TE may contribute to morbidity and mortality after LT. The objectives were to determine the incidence of early TE post-pediatric LT and compare differences between children with and without TE. A retrospective review of 88 transplanted children (January 2002-October 2007) was performed to determine the incidence of Doppler-confirmed DVT and ATE in the first month post-LT. Fourteen (16%) patients developed TE: DVT in seven (8%) and ATE in seven (8%) patients. Six of 88 (6.8%) developed symptomatic CVL-related DVT. Median (range) time post-LT to DVT and ATE were 7 (4-18) and 8 (1-31) days, respectively. There was no significant difference in age/body weight at LT between patients with or without DVT and ATE. There was no significant difference between patients with or without HAT in age and weight at LT, cold ischemic time, duration of surgery, hematocrit levels, whole-organ graft type, intraoperative FFP, high-risk CMV status, or early acute cellular rejection. In conclusion, the incidence of early TE post-pediatric LT was 16%, including DVT in 8%. Prospective studies are necessary to evaluate the role of prophylactic anticoagulation and potential modifiable risk factors post-pediatric LT.

Central Venous Catheter-related Complications in Patients with Hematological Malignancies: A Retrospective Analysis of Risk Factors and Prophylactic Measures

We retrospectively analyzed the incidence of thrombotic and infectious complications in relation with the use of central venous catheters (CVCs), in a series of patients with hematological malignancies and low platelet and leucocyte counts.

PATIENTS AND METHODS

126 patients with hematological malignancies were analyzed. A total of 207 CVCs were implanted: 137 centrally (CICCs) and 70 peripherally (PICCs). The median duration of the CVCs was 19 days for a total of 4051 catheter-days. Antithrombotic prophylaxis was unfractionated heparin (UFH), 2,500 IU daily by 24 h continuous infusion in 169 CVCs, low molecular weight heparin (LMWH), 3,800 IU daily by single bolus intravenous injection (i.v.) in 21 and warfarin in one. No prophylaxis was given in 16 CVCs. Thrombotic complications developed in 15.5% of the CVCs (7.9 events/1000 catheter days), and the frequency of infectious complications was 10.6% (5.2 events/1000 catheter days). On multivariate analysis thromboses were more frequent and earlier with PICCs than CICCs (p = 0.0001), and in patients on UFH (16.6%) than in LMWH prophylaxis (4.7%), but the last difference was not statistically significant. In conclusions the incidence of thrombotic complications in our series was comparable to that observed in non-thrombocytopenic patients and was significantly higher in those carrying PICC than CICC (p = 0.0001). There were fewer thrombotic events in the patients receiving i.v. LMWH prophylaxis than in those receiving i.v. UFH. The use of anticoagulants was safe and not associated with hemorrhages.

Incidence and diagnosis of thrombosis in children with short-term central venous lines of the upper venous system

OBJECTIVES

Deep venous thrombosis in children is frequently related to central venous lines. Study objectives were to determine objectively the incidence of deep venous thrombosis in children with short-term central venous lines and to assess the diagnostic value of venography, venous ultrasonography, and echocardiography, in a prospective cohort study.

METHODS

Consecutive children with congenital heart disease requiring short-term central venous lines in the upper venous system were screened systematically for deep venous thrombosis by using venography, venous ultrasonography, and echocardiography, according to standardized protocols.

RESULTS

The study population consisted of 90 children (median age: 2.7 years; range: birth to 18 years). Most central venous lines (97%) were located in the jugular veins. The overall incidence of deep venous thrombosis was 25 cases (28%) among 90 children. Venography identified deep venous thrombosis located in the subclavian and central veins but missed most deep venous thrombosis in the jugular veins. Venous ultrasonography had good sensitivity in the jugular veins but did not detect deep venous thrombosis in central veins. Echocardiography detected only 1 case of central deep venous thrombosis.

CONCLUSIONS

The incidence of central venous line-related deep venous thrombosis in children with short-term central venous lines is high and comparable to reports for children with long-term central venous lines. Sensitivities of venography, venous ultrasonography, and echocardiography in children vary depending on the affected venous segment. A combination of diagnostic tests is required for sensitive detection of central venous line-related deep venous thrombosis in the upper venous system.

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

Increased incidence of cancers and the development of totally implanted venous access devices that contain their own port to deliver chemotherapy will lead to a greater than before numbers of central venous catheter-related thrombosis (CVCT). Medical consequences include catheter dysfunction and pulmonary embolism. Vessel injury caused by the procedure of CVC insertion is the most important risk factor for development of CVCT. This event could cause the formation of a fresh thrombus, which is reversible in the large majority of patients. In some cases, thrombus formation is not related to catheter insertion. The incidence of CVC-related DVT assessed by venography has been reported to vary from 30 to 60% but catheter-related DVT in adult patients is symptomatic in only 5% of cases. The majority of patients with CVC-related DVT is asymptomatic or has nonspecific symptoms: arm or neck swelling or pain, distal paresthesias, headache, congestion of subcutaneous collateral veins. In the case of clinical suspicion of CVC-related deep venous thrombosis (DVT), compressive ultrasonography (US), especially with doppler and color imaging, currently is first used to confirm the diagnosis. Consequently, contrast venography is reserved for clinical trials and difficult diagnostic situations. There is no consensus on the optimal management of patients with CVC-related DVT. Treatment of CVC-related VTE requires a five- to seven-day course of adjusted-dose unfractionated heparin or low molecular weight heparin (LMWH) followed by oral anticoagulants. Long-term LMWH that has been shown to be more effective than oral anticoagulant in cancer patients with lower limb DVT, could be used in these patients. The efficacy and safety of pharmacologic prophylaxis for CVC related thrombosis is not established and the last recommendations suggest that clinicians not routinely use prophylaxis to try to prevent thrombosis related to long-term indwelling CVCs in cancer patients. Additional studies performed in high risk populations with appropriate dosage and timing will help to define which patients could benefit from prophylaxis.

Thyroid cancer causing obstruction of the great veins in the neck

Background and aims

To report our experience and review the literature of thyroid cancer obstructing the great veins in the neck, highlighting clinical aspects and response to treatment.

Methods

Clinical data were collected from the thyroid cancer register and from follow-up clinic visits of patients referred to the Thyroid Unit at the Royal Marsden Hospital. A Medline literature search was conducted between 1980 and 2007.

Results

Of 1448 patients with thyroid cancer on our cancer register and treated in our unit over the last 60 years, we identified five patients, four women and one man, aged 43 – 81 years with a median follow up of 28 (24–78) months in whom tumour had occluded the great veins in the neck. All patients underwent total thyroidectomy and all subsequently received ablative ¹³¹I with the exception of patient 3 whose post-operative isotope scan shown no significant ¹³¹I uptake. External beam radiotherapy to the neck and upper mediastinum was used for residual disease control in the 5 patients. The median survival was 28 months and the disease-free survival was 24 months. One patient remains asymptomatic but with disease 53 months after initial presentation. Survival in this small series is significantly better than that previously reported for this condition.

Conclusion

A multimodality therapeutic approach comprising surgery, radioiodine and external beam radiotherapy may give the best results for patients in whom thyroid cancer is occluding the great veins.

Diagnosis and Management of Subclavian Vein Thrombosis: Three Case Reports and Review of Literature

Axillosubclavian vein thrombosis is seen relatively infrequently in clinical practice when compared with lower limb deep-venous thrombosis; however, it is a condition that can result in significant morbidity if managed suboptimally. A multimodal treatment approach has been increasingly adopted with thrombolysis and/or thoracic outlet decompression being favored over anticoagulation alone, although the evidence base to support this approach is limited. In all, 3 cases are reported, which highlight numerous pertinent issues relating to the diagnostic and therapeutic options available.

A rare complication of hemodialysis catheters: superior vena cava syndrome

Central venous catheters in hemodialysis patients may result in superior vena cava (SVC) syndrome. With the increasing use of these catheters, the SVC syndrome will probably be more common among hemodialysis patients. This report describes 3 cases of SVC syndrome due to central venous catheters that developed in hemodialysis patients with previous multiple catheter placements.

Thromboses sur cathéter central chez le patient cancéreux

OBJECTIVES

Increased incidence of cancers and the development of totally implanted venous access devices that contain their own port to deliver chemotherapy will lead to a greater than before numbers of central venous catheter related thrombosis (CVCT). Medical consequences include catheter dysfunction and pulmonary embolism. Compared with lower extremity deep venous thrombosis (DVT) (3 d) and with non CVC associated thrombosis (5 d), CVCT is associated with an increased duration of hospitalisation (9 d). CVCT oftentimes leads to the need to replace such ports at an average cost of 4500 euros.

CURRENT KNOWLEDGE AND KEY POINTS

Vessel injury caused by the procedure of CVC insertion is the most important risk factor for development of CVCT. This event could cause the formation of a fresh thrombus, which is reversible in the large majority of patients. The incidence of CVC-related DVT assessed by venography has been reported to vary from 30 to 60% but catheter-related DVT in adult patients is symptomatic in only 5% of cases. The majority of patients with CVC-related DVT is asymptomatic or has non-specific symptoms: arm or neck swelling or pain, distal paresthesias, headache, congestion of subcutaneous collateral veins. In the case of clinical suspicion of CVC-related DVT, compressive ultrasonography (US), especially with Doppler and color imaging, currently is first used to confirm the diagnosis. The main criteria of color-Doppler US are visualization of mural thrombi or incompressibility of the veins. Consequently, contrast venography is reserved for clinical trials and difficult diagnostic situations. There is no consensus on the optimal management of patients with CVC-related DVT. Treatment of CVC-related VTE requires a 5- to 7-day course of adjusted-dose unfractionated heparin or LMWH followed by oral anticoagulants. Long-term LMWH that has been shown to be more effective than oral anticoagulant in cancer patients with lower limb DVT could be used in these patients. The optimal duration of oral anticoagulation treatment for CVC-related DVT is unknown, but patients with active cancer should be treated for at least 6 months or indefinitely.

FUTURE PROSPECTS AND PROJECTS

The efficacy and safety of pharmacologic prophylaxis for CVC related thrombosis is not established. Additional studies performed in high risk populations are needed to define if LMWH or oral anticoagulation is indicated in this clinical setting.

Upper limb deep vein thrombosis: a literature review to streamline the protocol for management

OBJECTIVE

The objective of this article is to provide up-to-date information about aetiology, pathogenesis, diagnostic modalities and treatment of upper limb deep vein thrombosis (ULDVT).

METHODS

Generic terms including ULDVT, axillary-subclavian DVT, and complications of central venous catheters were searched on electronic database. We analysed original studies, review articles and evaluation studies published over the last 25 years.

RESULTS

Forty-seven studies on ULDVT encompassing 2,557 patients were evaluated. The incidence of ULDVT was quoted 1-4% of the total DVT. Primary ULDVT (20% of the total) was due to activity-related venous trauma. Secondary ULDVT (80% of the total) was due to central venous catheters and malignancy. Duplex ultrasound (sensitivity 78-100% and specificity 82-100%), contrast venography (gold standard) and magnetic resonance venography were the diagnostic tools used. Pulmonary embolism (2-35%) and post-thrombotic syndrome (7-46%) were the main sequelae. Anticoagulation was the universal intervention, giving 79% symptom relief (13.2% rethrombosis rate). Thrombolysis and/or percutaneous thrombectomy were used in 38% of cases for the management of ULDVT, giving 83% symptom relief (90% recanalization rate and 9% rethrombosis rate). Surgical decompression, venous angioplasty and superior vena cava filters were the main adjunctive interventions.

CONCLUSION

ULDVT, although rare, is associated with considerable morbidity and mortality (29-40%) due to potential risks of pulmonary embolism, post-thrombotic syndrome and loss of vascular access. Simple anticoagulation is suitable for the majority of patients. Thrombolysis/thrombectomy is often successful but less frequently used. Surgical decompression, venous angioplasty and superior vena cava filters have some role in recurrent cases. An optimal management protocol can be established using a multimodality approach.

Prevalence of upper extremity deep venous thrombosis diagnosed by color Doppler duplex sonography in cancer patients with central venous catheters

OBJECTIVE

The purpose of this study was to review the literature concerning upper extremity deep venous thrombosis (UEDVT) diagnosed by color Doppler duplex sonography (CDDS) in cancer patients with indwelling central venous catheters (CVCs).

METHODS

From computerized databases (MEDLINE and Ovid), relevant publications regarding CDDS of the upper limb veins in cancer patients with CVCs were reviewed.

RESULTS

Patients with malignancy have a higher rate of thrombosis, which is increased by the presence of CVCs. Screening CDDS in asymptomatic patients showed CVC-related UEDVT in 11.7% to 44% of patients. In symptomatic cancer patients, the range was similar to the asymptomatic ones, 6.7% to 48%. The presence of a CVC almost doubled the incidence of UEDVT in symptomatic patients. Color Doppler duplex sonography is an accurate examination for the diagnosis of UEDVT, with sensitivity ranging from 78% to 100% and specificity ranging from 82% to 100%. The main obstacle for the diagnosis of UEDVT is the presence of overlying bones, making it difficult to visualize and impossible to directly assess by compression techniques. Color and spectral Doppler sonography and the use of small transducers aid in the diagnosis. When several parameters are evaluated in combination, CDDS is a reliable method for diagnosing CVC-related thrombosis.

CONCLUSIONS

Great variability in the prevalence of catheter-related thrombosis in cancer patients has been reported, although it is uniformly higher compared with patients without cancer. Color Doppler duplex sonography is the modality of choice for the diagnosis of CVC-related UEDVT in symptomatic cancer patients and for screening for asymptomatic thrombosis in this specific population.

Therapy Insight: venous-catheter-related thrombosis in cancer patients

Central venous catheters (CVCs) have improved the management of patients with cancer substantially, by facilitating chemotherapy and supportive therapy. The use of CVCs is associated with complications such as infection and upper-limb deep vein thrombosis (UL-DVT). The incidence of clinically overt UL-DVT related to the use of CVCs ranges between 2% and 4%. In the most recent study, the incidence of CVC-related thrombosis, as screened by venography, was approximately 18% in the absence of prophylaxis. In cancer patients with CVC-related UL-DVT, the incidence of clinically overt pulmonary embolism was between 15% and 25%, and the incidence of autopsy-proven pulmonary embolism was up to 50%. Pathogenic factors for CVC-related thrombosis include vessel injury caused by the CVC insertion procedure, venous stasis because of the indwelling CVC, and hypercoagulability associated with cancer. Recent studies have not confirmed a benefit for prophylaxis with antithrombotic agents for CVC-related thrombosis. The recommended treatment for CVC-related thrombosis is based on long-term anticoagulant therapy, with or without catheter removal.

Thromboembolic complications in children with cancer

Thrombosis is a significant problem in patients with cancer. The impact of thromboembolism in association with childhood cancer is not clearly defined. Similarly the information of prevention and management of thromboembolic events in children receiving cancer-therapy is limited. This review aims to examine current knowledge regarding the epidemiology, pathophysiology and management of thrombosis in association with cancer in children.

Central venous catheters: the role of radiology

The insertion and management of long-term venous catheters have long been the province of anaesthetists, intensive care physicians and surgeons. Radiologists are taking an increasing role in the insertion of central venous catheters (CVCs) because of their familiarity with the imaging equipment and their ability to manipulate catheters and guide-wires. The radiological management of the complications of CVCs has also expanded as a result. This article reviews the role of radiology in central venous access, covering the detection and management of their complications.

Prevalence of inherited prothrombotic abnormalities and central venous catheter-related thrombosis in haematopoietic stem cell transplants recipients

In this prospective study, we assessed the incidence of central venous catheter (CVC)-related thrombosis in haematopoietic stem cell transplant (HSCT) recipients. We determined the contribution of inherited prothrombotic abnormalities in blood coagulation to CVC-related thrombosis in these patients. The study was conducted between May 2002 and September 2004. CVCs were externalized, nontunneled, polyurethane double lumen catheters. Before catheter insertion, laboratory prothrombotic markers included factor V Leiden, the prothrombin gene Gly20210A mutation, plasma antithrombin levels, and protein C and S activity. All patients were systematically examined by ultrasonography just before, or <24 h after, catheter removal, and in case of clinical signs of thrombosis. A total of 171 patients were included during the 28-month study period. Five (2.9%) and three (1.7%) patients had evidence of protein C and protein S deficiency, respectively. Only one patient had an antithrombin deficiency (0.6%). In total, 10 patients (5.8%) were heterozygous for the factor V Leiden mutation, and one patient had heterozygous prothrombin G20210A mutation (0.6%). We observed a CVC-related thrombosis in 13 patients (7.6%). Thrombosis was diagnosed in four out of 20 patients (20%) with a inherited prothrombotic abnormality compared to nine of 151 patients (6%) who did not have a thrombophilic marker (relative risk 3.3 CI 95% 1.1-9.9). Our results suggest that inherited prothrombotic abnormalities contribute substantially to CVC-related thrombosis in HSCT recipients. In view of physicians' reluctance to prescribe prophylactic anticoagulant treatment in these patients, a priori determination of inherited prothrombotic abnormalities may form a basis to guide these treatment decisions.

Notions d’hémodynamique et techniques ultrasonores pour l’exploration des veines du cou et des membres

Deep venous thrombosis and venous insufficiency are now easily diagnosed with US imaging. US allows anatomic evaluation of the vessel walls and dynamic evaluation of flow velocities. Knowledge of vascular anatomy and physiology is required to interpret US data. The sensitivity of US for the diagnosis of deep venous thrombosis is up to 95% at the leg level, 98% at the popliteal level, and 100% at the femoral level with a specificity of nearly 100%. Venography is thus rarely performed. The sensitivity for the diagnosis of deep venous thrombosis at the neck level is up to 90%. Follow-up can easily be performed because of the wide availability of US.

Sonographic evaluation of upper extremity deep venous thrombosis

OBJECTIVE

The purpose of this presentation is to review the techniques of performing an upper extremity Doppler examination, in addition to illustrating the sonographic appearances of acute and chronic upper extremity deep venous thrombosis (UEDVT).

METHODS

The risk factors and complications of UEDVT are discussed, and the anatomy of the upper extremity deep venous system as well as examination techniques are described. Cases of acute and chronic deep venous thrombosis were also chosen to illustrate the spectrum of sonographic appearances.

RESULTS

Color Doppler sonography is accurate in the diagnosis of UEDVT. However, in cases of equivocal Doppler findings, or when the sonographic findings are normal but clinical suspicion for central venous thrombosis is high, magnetic resonance or contrast venography is necessary for further evaluation.

CONCLUSIONS

Color Doppler sonography is a rapid and noninvasive technique in the evaluation of venous disease in the upper extremity and is the modality of choice in screening for UEDVT.

Infectious Complications of Central Venous Catheters Increase the Risk of Catheter-Related Thrombosis in Hematology Patients: A Prospective Study

Purpose

We studied whether the risk of central venous catheter (CVC) -related thrombosis increased after an episode of CVC-related infection in patients undergoing intensive chemotherapy. Secondly, we determined whether thrombosis can be predicted or excluded by CVC lock fluid surveillance cultures.

Patients and Methods

In a prospective setting, 105 consecutive patients were carefully examined for CVC-related infection and thrombosis. In all patients, microbial surveillance cultures of CVC lock fluid were taken every other day. All patients with clinical suspicion of CVC-related thrombosis underwent Doppler ultrasound or additional venography.

Results

The cumulative incidence of CVC-related infection was 24% (25 of 105 patients). Clinically manifest thrombosis occurred in 13 (12%) of 105 patients. In patients with CVC-related infection, the risk of thrombosis increased markedly in comparison to those without infection (relative risk, 17.6; 95% CI, 4.1 to 74.1). In patients having two or more positive subsequent CVC lock fluid cultures with identical micro-organisms, 71.4% developed thrombosis, as compared with 3.3% in patients with negative or a single positive culture.

Conclusion

The risk of clinically manifest thrombosis is increased after an episode of CVC-related infection in patients undergoing intensive chemotherapy. Surveillance culturing of CVC lock fluid may be clinically useful in estimating the risk for thrombosis and the instigation of focused early intervention.

Thrombose symptomatique sur cathéter veineux central de longue durée en oncologie : un score de risque prédictif?

BACKGROUND

Central venous catheters are essential to management of cancer patients. Thrombotic complications are potentially severe, but it is difficult to prescribe systematically a prophylactic treatment. So it is necessary to identify the higher risk patients who need a prophylaxis.

AIM

To identify factors associated with the development of clinically significant venous thrombosis in cancer patients with long-term catheters.

METHODS

Monocentric prospective study about 5447 long-term central venous catheters inserted into patients receiving treatment for solid tumours (50% of breast cancers). Clinically significant catheter-related thromboses are confirmed by ultrasonography, phlebography or scanner.

RESULTS

The median duration of catheter use is 147 days. There are 135 clinically significant catheter-related thromboses. The risk for thrombosis is 0.1149 events per 1000 device days. The incidence of symptomatic thrombosis is 0.9% at 30 days, 1.36% at 60 days, 1.83% at 90 days and 2.25% at 120 days. The multivariate analysis shows that female sex, duration of insertion procedure (more than 25 minutes) and place of insertion (femoral place) are factors associated with clinically significant venous thrombosis. The right subclavian insertion causes less risk. The catheters with their tip too "high" in the superior vena cava are systematically changed, so that the position of the catheter tip does not appear as a risk factor in our study. The disease stage and the type of treatments are not well examined.

CONCLUSIONS

A predictive score can be made with the three risk factors that have been identified. Thanks to this score it is possible to determine the patients with higher risk for clinically significant catheter-related venous thrombosis. These patients must be more frequently watched over and must receive a prophylactic treatment. The best prophylaxis has to be determined.

Catheter-Related Thrombosis in Cancer Patients: Pathophysiology, Diagnosis, and Management

Central venous catheters (CVCs) are commonly used in oncology patients. Up to 50% of CVCs are complicated by thrombosis within the catheter or the blood vessel. These thrombi are the result of local tissue damage, the catheter itself, and the thrombophilia of cancer. Frequent flushes with saline or heparin may reduce the frequency of catheter dysfunction but do not reduce the rate of deep venous thrombosis (DVT) in the catheterized blood vessel. Efforts to use prophylactic heparin or warfarin to reduce catheter-related DVT have not been rewarding.

Incidence and Risk Factors of Early Venous Thrombosis Associated with Permanent Pacemaker Leads

INTRODUCTION

Pacemaker lead implantation can cause thrombosis, which can be associated with serious local morbidity and complicated by pulmonary embolism. Few reliable estimates of the incidence of thrombosis have been reported. The contribution of established risk factors to venous thrombosis in patients with implanted pacemaker leads is unknown.

METHODS AND RESULTS

One hundred forty-five consecutive patients n = 145) underwent routine clinical and Doppler ultrasound evaluation for thrombosis before and 3, 6, and 12 months after lead implantation. Established risk factors for venous thrombosis were assessed in detail for all patients. Clinical outcome, including clinically manifest thrombosis, pulmonary embolism, associated pacemaker lead infection, complicated reinterventions, and death, was evaluated. Thrombosis was observed in 34 (23%) of 145 patients. Thrombosis did not cause any signs or symptoms in 31 patients but resulted in overt clinical symptoms in 3 patients. The absence of anticoagulant therapy, use of hormone therapy, and a personal history of venous thrombosis were associated with an increased risk of thrombosis. The risk of thrombosis increased in the presence of multiple pacemaker leads compared to a single lead.

CONCLUSION

Established risk factors for venous thrombosis and the presence of multiple pacemaker leads contribute substantially to the occurrence of thrombosis associated with permanent pacemaker leads. Risk factor assessment prior to implantation may be useful for identifying patients at risk for thrombotic complications. Preventive management in these patients is warranted.

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.

Central venous catheter related thrombosis in haematology patients and prediction of risk by screening with Doppler-ultrasound

Patients with a central venous catheter (CVC) who receive intensive chemotherapy or a stem cell transplantation for haematological disease are at risk for developing CVC-related thrombosis. To study the incidence of thrombosis, 105 consecutive patients underwent serial Doppler-ultrasound and we evaluated whether clinically manifest thrombosis could be predicted by screening with Doppler-ultrasound. Patients with subclavian or jugular inserted CVCs were clinically assessed each day for signs and symptoms of thrombosis. Additional Doppler-ultrasound screens were performed weekly by an independent physician in all patients until CVC removal. Doppler-ultrasound recordings were assessed by two blinded observers. In cases of clinically suspected thrombosis, the attending physicians followed routine diagnostic and therapeutic procedures. The overall cumulative incidence of CVC-related thrombosis was 28.6% (30 of 105 patients). Of the 30 patients with thrombosis, 26 had subclinical thrombosis by Doppler-ultrasound, nine of whom developed clinically manifest thrombosis later. Four patients had clinically manifest thrombosis without prior abnormal Doppler-ultrasound. In cases of subclinical thrombosis the risk of developing symptomatic disease increased sevenfold (34.6% vs. 5.1%). Doppler-ultrasound screening may be useful to identify those patients that are at high and low risk for clinically manifest CVC-related thrombosis.

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.

Central line thrombosis in patients with cancer

Central venous catheters are used frequently to care for patients with cancer and often serve as long-term venous access. Catheter-related central venous thrombosis is a serious and common complication in these patients. The incidence of this event ranges from 2 to 40%. Potential risk factors are catheter position, size of the catheter, and perhaps site of insertion. The diagnosis of catheter-associated deep venous thrombosis may be difficult. Doppler ultrasound has a lower accuracy in this setting than it does in symptomatic lower extremity venous thrombosis. No clinical management studies have validated the practice of withholding anticoagulant therapy in patients with a negative Doppler ultrasound. The practice of prophylaxis with low-dose warfarin or low-molecular-weight heparin has been recommended, although results from recent studies have called this into question. Larger, prospective, randomized trials with a uniform population of patients or stratification of risk factors will be essential to address this issue further.