Successful use of tissue plasminogen activator in catheter-related intracardiac thrombus of a premature infant

NEOnatal Central-venous Line Observational study on Thrombosis (NEOCLOT): evaluation of a national guideline on management of neonatal catheter-related thrombosis

BACKGROUND

In critically ill (preterm) neonates, central venous catheters (CVCs) are increasingly used for administration of medication or parenteral nutrition. A serious complication, however, is the development of catheter-related thrombosis (CVC-thrombosis), which may resolve by itself or cause severe complications. Due to lack of evidence, management of neonatal CVC-thrombosis varies among neonatal intensive care units (NICUs). In the Netherlands an expert-based national management guideline has been developed which is implemented in all 10 NICUs in 2014.

METHODS

The NEOCLOT study is a multicentre prospective observational cohort study, including 150 preterm and term infants (0-6 months) admitted to one of the 10 NICUs, developing CVC-thrombosis. Patient characteristics, thrombosis characteristics, risk factors, treatment strategies and outcome measures will be collected in a web-based database. Management of CVC-thrombosis will be performed as recommended in the protocol. Violations of the protocol will be noted. Primary outcome measures are a composite efficacy outcome consisting of death due to CVC-thrombosis and recurrent thrombosis, and a safety outcome consisting of the incidence of major bleedings during therapy. Secondary outcomes include individual components of primary efficacy outcome, clinically relevant non-major and minor bleedings and the frequency of risk factors, protocol variations, residual thrombosis and post thrombotic syndrome.

DISCUSSION

The NEOCLOT study will evaluate the efficacy and safety of the new, national, neonatal CVC-thrombosis guideline. Furthermore, risk factors as well as long-term consequences of CVC-thrombosis will be analysed.

TRIAL REGISTRATION

Trial registration: Nederlands Trial Register NTR4336 . Registered 24 December 2013.

Risk Factors for Intracardiac Thrombosis in the Right Atrium and Superior Vena Cava in Critically Ill Neonates who Required the Installation of a Central Venous Catheter

BACKGROUND

Central venous catheter (CVC) installation is essential for the treatment of critically ill neonates; however, it is associated with the development of neonatal intracardiac thrombosis, which is a complication that is associated with a poor prognosis. We aimed to identify specific risk factors for the development of intracardiac thrombosis in the right atrium (RA) and superior vena cava (SVC) related to the use of CVC in critically ill neonates.

METHODS

A case-control study was conducted at the tertiary referral neonatal intensive care unit of the Pediatric Hospital Siglo XXI in Mexico City, Mexico from 2008 to 2013. The included cases (n = 43) were de novo patients with intracardiac thrombosis in the RA and SVC diagnosed by echocardiography. The controls (n = 43) were neonates without intracardiac thrombosis or thrombosis at other sites. A logistic regression analysis was conducted, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

The independent risk factors for intracardiac thrombosis in the RA and SVC were the surgical cut-down insertion technique (OR = 2.98; 95% CI: 1.18-9.10), a maternal history of gestational diabetes/diabetes mellitus (OR = 10.64; 95% CI: 1.13-121.41), Staphylococcus epidermidis infection (OR = 7.09; 95% CI: 1.09-45.92), and CVC placement in the SVC (OR = 5.77; 95% CI: 1.10-30.18).

CONCLUSION

This study allowed us to identify several contributing factors to the development of intracardiac thrombosis in the RA and SVC related to the installation of a CVC in a subgroup of critically ill neonates. Multicenter and well-designed studies with a larger number of patients could help validate our findings and/or identify other risk factors that were not identified in the present study.

Thrombosis in the Neonatal Intensive Care Unit

Neonates have the highest risk for pathologic thrombosis among pediatric patients. A combination of genetic and acquired risk factors significantly contributes to this risk, with the most important risk factor being the use of central venous catheters. Proper imaging is critical for confirming the diagnosis. Despite a significant number of these events being life- and limb-threatening, there is limited evidence on what the appropriate management strategy should be. Evaluation and treatment of any neonate with a clinically significant thrombosis should occur at a tertiary referral center that has proper support.

Clinical experience with recombinant tissue plasminogen activator in the management of intracardiac and arterial thrombosis in children

Thrombotic events may complicate the clinical course of many pediatric diseases. Drugs for therapeutic thrombolysis include streptokinase, urokinase and tissue plasminogen activator (t-PA). There is less experience with recombinant t-PA (rt-PA) in children. We aimed to present our experiences with rt-PA in children with intracardiac or peripheral arterial thrombus. We retrospectively reviewed the children who received rt-PA for thrombus. Twenty-two children (13 boys, 9 girls; age range: 1 day-17 years) with intracardiac (n = 5), prosthetic heart valve (n = 2) and peripheral arterial (n = 15) thrombus were evaluated. Twelve (54%) had congenital heart disease, two (9%) had rheumatic heart disease, three (14%) had leukemia and five (23%) had documented sepsis, prematurity or meconium aspiration syndrome. Ten of the 15 peripheral arterial thromboses were observed following cardiac catheterization. Three of the five intracardiac thrombi were detected in children with leukemia. All children received low-molecular-weight heparin. rt-PA (alteplase) infusion (at a dose of 0.01-0.5 mg/kg per h) was administered for different time periods (3-66 h). Ten of 11 patients with peripheral arterial occlusion and three of five patients with intracardiac thrombus showed full recovery. However, there was no response in two patients with intracardiac thrombus and in two patients with heart valve thrombus. Nose bleeding, melena and decreased serum fibrinogen concentration were observed in seven patients during the rt-PA infusion. All bleedings stopped after cessation of rt-PA infusion, and no blood transfusion was required in any patient. We conclude that rt-PA infusion seems effective and well tolerated in children for the treatment of peripheral arterial and intracardiac thrombus.

A neonatal thrombosis patient treated successfully with recombinant tissue plasminogen activator

Herein we report an asphyctic preterm neonate with respiratory distress and prothrombotic risk factors that responded positively to rtPA treatment following 2 attacks of acute thrombosis.

Conflict of interest:None declared.

Successful use of low molecular weight heparin in intracardiac thrombus of an extremely low birth weight infant

The sick premature infants have high risk for thrombosis. Although therapeutic options include close observation, anticoagulation, thrombolytic therapy, and thrombectomy, guidelines for the management of neonatal arterial and venous thrombosis vary greatly among different centers. The authors report their experience using low molecular weight heparin (enoxaparin), with safe and successful resolution of right atrial thrombus, in an extremely low birth weight infant.

Management of neonatal thrombosis

Neonates have one of the highest risks for thromboembolism among pediatric patients. This risk is attributable to a combination of multiple genetic and acquired risk factors. Despite a significant number of these events being either life threatening or limb threatening, there is limited evidence on appropriate management strategy. Most of what is recommended is based on uncontrolled studies, case series, or expert opinion. This review begins with a discussion of the neonatal hemostatic system, focusing on the common sites and imaging modalities for the detection of neonatal thrombosis. Perinatal and postnatal risk factors are presented and management options discussed.

Evaluation and Treatment of Neonatal Thrombus Formation in 17 Patients

Introduction: Thrombosis is a rare but serious event in neonates. Perinatal risk factors associated with the developing hemostatic system increase the risk of thromboembolism. Treatment protocols vary between different centers. In this study, thrombosis and subsequent treatment were evaluated in 17 neonates hospitalized in a neonatal intensive care unit. This is the largest series reported to date. Method: From January 2007 to December 2009, thrombosis was diagnosed in 17 newborns hospitalized in a neonatal intensive care unit. Most were treated with recombinant tissue plasminogen activator (r-tPA) and enoxaparin as anticoagulant therapy. Results: Eleven courses of r-tPA therapy were administered to 10 patients. Sixteen patients received low-molecular-weight heparin (LMWH) treatment. None of the patients had hemorrhagic complications due to therapy. Recurrence was observed in 1 patient 1.5 months after the first course of r-tPA and retreatment was performed. A complete decrease in thrombus size was achieved in 9 patients and a partial decrease in 5 patients. One patient died before treatment was initiated; another died at the end of the first day of treatment and thus could not be evaluated. One patient who had a homozygous mutation for factor V Leiden did not respond to treatment and the extremity involved was amputated. Conclusions: Thrombosis in neonates is a multifactorial disorder. Treatment consisting of r-tPA and an anticoagulant was shown to be a safe and effective approach to clot dissolution in neonates.

Clinical experience with alteplase in the management of intracardiac and major cardiac vessels thrombosis in pediatrics: a case series

BACKGROUND AND OBJECTIVES

Experience with alteplase in pediatric patients is limited and recommendations are extrapolated from adult data. Comprehensive guidelines on the management of thromboembolic events in this group are lacking. We assessed the efficacy and safety of alteplase (recombinant tissue plasminogen activator) in the management of intracardiac and major cardiac vessel thrombosis in pediatric patients.

METHODS

All pediatric patients, 14 years of age and younger, with intracardiac or major cardiac vessel thrombus who were treated with alteplase from 1997 to 2004 at our tertiary care institute were identified through the pharmacy database. Patient data were retrospectively evaluated for the efficacy and safety of altepase.

RESULTS

Five cases were eligible out of nineteen who received alteplase. Patient ages ranged from 40 days to 13 years. The initial dose of alteplase ranged from 0.3 to 0.6 mg/kg followed by a continuous infusion in three patients with a dosage range between 0.05 and 0.5 mg/kg/hr, while intermittent infusion was used in the other two patients. The duration of therapy ranged from 2 to 4 days. By the end of the treatment, two patients had complete resolution of thrombus and one had partial resolution. Two patients failed to respond and had "old" thrombus. Major bleeding events were reported in three patients. The rest had minor bleeding events.

CONCLUSION

Alteplase may effectively dissolve intracardiac thrombi, particularly when freshly formed. Continuous infusion for a long duration appears to be associated with an increased risk of major bleeding. Optimal dose and duration of infusion are still unknown.

The evaluation and management of postnatal thromboses

In the pediatric population, neonates have the highest risk for thromboembolism (TE), most likely due to the frequent use of intravascular catheters. This increased risk is attributed to multiple risk factors. Randomized clinical trials dealing with management of postnatal thromboses do not exist, thus, opinions differ regarding optimal diagnostic and therapeutic interventions. This review begins with an actual case study illustrating the complexity and severity of these types of cases, and then evaluates the neonatal hemostatic system with discussion of the common sites of postnatal thrombosis, perinatal and prothrombotic risk factors, and potential treatment options. A proposed step-wise evaluation of neonates with symptomatic postnatal thromboses will be suggested, as well as future research and registry directions. Owing to the complexity of ischemic perinatal stroke, this topic will not be reviewed.

The evaluation and management of neonatal coagulation disorders

Neonatal hemostatic abnormalities can present diagnostic and therapeutic challenges to the physician. Developmental deficiencies and/or increases of certain coagulation proteins, coupled with acquired or genetic risk factors, can result in a hemorrhagic or thromboembolic emergency. The timely diagnosis of a congenital hemorrhagic or thrombotic disorder can avoid significant long-term sequelae. However, due to the lack of randomized clinical trials addressing the management of neonatal coagulation disorders, treatment strategies are usually empiric and not evidence-based. In this chapter, we will review the neonatal hemostatic system and will discuss the most common types of hemorrhagic and thrombotic disorders. Congenital and acquired risk factors for hemorrhagic and thromboembolic disorders will be presented, as well as current treatment options. Finally, suggested evaluations for neonates with either hemorrhagic or thromboembolic problems will be reviewed.

Outcome of cardiac thrombi in infants

Use of central lines in the neonatal intensive care unit (NICU) has led to the formation of intracardiac thrombi. A paucity of data exists on the management of neonatal cardiac thrombi, with the few reported cases focusing on outcomes following thrombolytic therapy. This study was undertaken to evaluate the outcome of cardiac thrombi in neonates who do not receive thrombolytic therapy. Nineteen patients younger than 3 months of age diagnosed with cardiac thrombi were included. All 19 patients had a central line. Management consisted of a combination of antibiotics and low-molecular-weight heparin (n = 16) or surgical removal (n = 2). In one case, no treatment was instituted. One patient was lost to follow-up after partial resolution of the thrombus. Complete thrombus resolution occurred in 18 patients, 9 with negative blood cultures and 9 with positive blood cultures. It took longer for resolution of thrombi associated with positive blood cultures than for sterile thrombi. No patient had evidence of thrombus embolization. From these data we concluded that the natural history of cardiac thrombi is resolution. Infected thrombi require more prolonged therapy. Surgery is seldom required and thrombolytics are not usually necessary for clot resolution.

A giant thrombus in the right ventricle of a newborn with Down syndrome: successful treatment with rt-PA

An association between thromboembolic events and Down syndrome (DS) has been increasingly reported in the literature. It is not clear whether patients with DS have increased risk for thrombotic disorders or there is a coincidence. We present a case of giant right ventricular thrombus in a neonate with DS. Risk factors for thrombosis in the present case were neonatal sepsis and dehydration. There was no congenital heart anomaly. The patient was treated successfully using recombinant tissue plasminogen activator. Recombinant tissue plasminogen activator seems to be a safe and effective thrombolytic therapy in neonates.

Management of a large organized intraatrial catheter-tip thrombus in a child with acquired immunodeficiency syndrome using escalating tissue plasminogen activator infusions

OBJECTIVES

To describe the dissolution of a large organized intraatrial catheter-tip thrombus using a novel aggressive dose escalation of tissue plasminogen activator infusion.

DESIGN

Case report.

SETTING

A six-bed pediatric intensive care unit (ICU) at a university hospital.

PATIENT

An 8-yr-old with acquired immunodeficiency syndrome with a large organized intraatrial thrombus at the tip of an indwelling central venous catheter placed for total parenteral nutrition 2 months before presentation.

INTERVENTION

Escalating dose of tissue plasminogen activator infusion.

MEASUREMENTS

A large intraatrial catheter-tip thrombus (2.5 x 3 cm) was an incidental finding on an echocardiogram done to assess cardiac function. The thrombus occupied almost half the right atrial cavity and hit the tricuspid valve with each heartbeat without obstruction of tricuspid inflow. The catheter had no blood return from either lumen for >1 month. Protein C, protein S, and antithrombin III were normal, and factor V Leiden and prothrombin gene mutations were absent. Blood cultures were negative. Pediatric and cardiovascular surgeons recommended open-heart surgery as the safest option for catheter removal to avoid the risk of superior vena cava occlusion, vascular rupture, or embolization. A second opinion concurred. A trial of thrombolytic therapy with tissue plasminogen activator infusions was started at 0.1 mg/kg/hr for 6 hrs daily. No change in thrombus size was seen on a followup echocardiogram after 4 days. An aggressive dose escalation (0.15, 0.2, 0.25 mg/kg/hr for 6 hrs) was done over the next 5 days in an attempt to avoid open-heart surgery. Risks regarding disseminated intravascular coagulation and bleeding were presented to the parents.

MAIN RESULTS

Followup echocardiogram on day 10 showed complete resolution of the thrombus. No changes in respiratory/hemodynamic status or oxygen saturation were observed. Studies for disseminated intravascular coagulation remained stable, and no clinical bleeding was seen. The catheter was safely removed surgically; pathology examination showed no residual thrombus.

CONCLUSIONS

Prolonged infusion of tissue plasminogen activator in escalating doses was safe and effective in the management of a large intracardiac catheter-tip thrombus and helped avoid open-heart surgery. In view of the potential hazards of tissue plasminogen activator, close pediatric ICU monitoring is indicated with the use of high-dose tissue plasminogen activator infusions.