Catheter-directed thrombolysis with recombinant tissue plasminogen activator for acute pulmonary embolism after fontan operation

Catheter-directed thrombolysis for in situ pulmonary artery thrombosis in children

In situ pulmonary artery thrombosis (ISPAT) is a unique form of pulmonary embolism characterized by local formation of thrombus in the pulmonary arteries. We present here a baby with hypoplastic left heart syndrome who developed ISPAT after Glenn surgery. The patient underwent catheter-directed thrombolysis, followed by systemic anticoagulation with excellent results.

Pulmonary Embolism in a Neonate Following Modified Norwood Procedure With Sano Shunt

Pulmonary embolism is a rare but potentially fatal complication in neonates with congenital heart disease. The authors report a case of pulmonary embolism in the immediate postoperative period following modified Norwood procedure with Sano shunt. In addition, this report discusses the initial evaluation and available anticoagulation options to treat pulmonary embolism in children with congenital heart disease.

How I treat pediatric venous thromboembolism

The incidence of pediatric venous thromboembolism (VTE) has been increasing significantly over the past decade in part as a result of increased recognition of this serious disorder but more so because of the increased use of central venous catheters and other technological advancements involved in the care of ill children. Management of pediatric VTE is a complex undertaking, considering that the vast majority of children who develop this complication have serious underlying medical disorders. Although the incidence is rising, in comparison with adults, this remains a relatively rare disorder, and as such, large-scale clinical trials have not been completed, rendering management decisions to be based on extrapolation from adult data and the experience of the treating physician. Clearly, both are fraught with problems. Thus, day-to-day management remains more art than science until such time that the results from clinical trials (many of which are under way) become available. This edition of "How I Treat" describes the author's experience in managing 3 common scenarios that one may encounter in pediatric thrombosis and suggests a logical approach to such situations. Furthermore, the author provides 3 algorithms to help guide management decisions.

[A 49-year-old woman with deep vein thrombosis, pulmonary embolism, and left-sided paralysis]

We report the case of a 49-year-old female patient who was admitted stationary because of a left-sided paralysis which had appeared some hours before. An embolic occlusion of the right A. cerebri media turned out to be the cause. A paradoxical embolism could be assumed because of an existing deep vein thrombosis and an increased right-ventricular pressure within a hemodynamically relevant fulminant pulmonary embolism as well as the additional existence of a patent foramen ovale (PFO). Systemic lysis as treatment of the pulmonary embolism was contraindicated because slight bleeding had occurred in the area of the right basal ganglia after treatment of the embolic occlusion of the right A. cerebri media by a local lysis. Subsequently and in the acuteness, a catheter interventional PFO-closure via a double-umbrella device was placed and the pulmonary embolism was effectively treated by a local lysis through the insertion of a pigtail-catheter into the right pulmonary artery.

Thromboembolism and the role of anticoagulation in the Fontan patient

Among factors contributing to morbidity and failure of the Fontan circulation is the group of events referred to as thromboembolic complications. These events have been variously attributed to low flow states, stasis in the venous pathways, right-to-left shunts, blind cul-de-sacs, prosthetic material, atrial arrhythmias, and hypercoagulable states. Numerous investigations, most retrospective, have been undertaken to characterize thromboembolic events; describe the frequency and circumstances of these occurrences; and relate the risk of these events to patient, surgical, hemodynamic, and hematologic factors. Practices vary widely with respect to strategies of prophylactic anticoagulation in the hopes of minimizing the occurrence and morbidity of thromboembolism after Fontan operations. Review of the literature suggests that the factors associated with thromboembolic events after Fontan operations likely represent a complex field of biologic factors with multiple interactions. It is unlikely that a single agent will represent the solution to this complex problem.

Hemorrhagic Complications After Off-Label Thrombolysis for Ischemic Stroke

BACKGROUND AND PURPOSE

Only 2% to 4% of patients with acute ischemic stroke receive thrombolytic therapy resulting from the current strict inclusion criteria among other issues. Safety of intravenous and intraarterial thrombolysis in off-label situations is controversially discussed. We sought to review the reports on such patients regarding intra- and extracranial hemorrhage.

SUMMARY OF REVIEW

A MEDLINE search for off-label uses of thrombolysis revealed reports on 273 patients treated with intraarterial or intravenous thrombolysis for ischemic stroke. Symptomatic intracranial hemorrhage occurred in 19 of 273 patients (6.95%) and extracranial hemorrhage in 17 of 273 (6.22%).

CONCLUSIONS

These data suggest that the overall bleeding risk in off-label thrombolysis may not be as high as presumed. However, the small number of patients in each group and the likely underreporting of worse outcomes preclude drawing any conclusion as to specific treatment recommendations. Selected patients might benefit, however, from thrombolysis in situations not currently considered in the inclusion criteria. To obtain a meaningful database, a registry for off-label thrombolysis should be created.

Catheter-Directed Thrombolysis of Acute Deep Vein Thrombosis in the Lower Extremity of a Child with Interrupted Inferior Vena Cava

We present the case of a 14-year-old girl who developed acute deep vein thrombosis (DVT) in her right lower extremity. Laboratory testing revealed protein S deficiency, and the patient's father also had this abnormality with a history of lower extremity DVT. Manual thromboaspiration followed by catheter-directed thrombolysis resulted in total clearance of all thrombi. Computed tomography and later venography revealed an interrupted inferior vena cava. Catheter-directed thrombolysis is an established treatment for adults with acute DVT. To the best of our knowledge, this report is the first to describe catheter-directed thrombolysis in a pediatric patient with lower extremity DVT. Our results suggest that catheter-directed thrombolysis is safe and effective for use in selected older children and adolescents with acute DVT in the lower extremity.

Thrombolytic therapy in children

Thrombolysis is increasingly considered a treatment option in newborns and children with arterial and venous thromboembolic events, or occluded central venous lines. However, no uniform recommendations are available with regard to indications, drug of choice, route of administration, and dosing regimen. Thus, several protocols are used for the different thrombolytic agents, leading to differing outcome with respect to the effectiveness of therapy and bleeding complications. This article will summarize the available information on the use of thrombolytic agents in newborns and children, focussing on the potential indications, efficacy and safety profiles, and evidence supporting dosing schedules.

Thrombolysis of venous and arterial thrombosis by catheter-directed low-dose infusion of tissue plasminogen activator in children

Thrombolytic therapy is a well-defined treatment option for arterial and venous thrombosis in adults. In contrast, uniform recommendations regarding the indication, route of administration, and dosing of thrombolytic therapy in children are not available. The authors report the successful resolution of bilateral pulmonary embolism and popliteal artery thrombosis in an 11-year-old girl and 13-year-old girl, respectively, by catheter-directed thrombolysis with low-dose recombinant tissue plasminogen activator. Catheter-directed low-dose thrombolysis is an efficient treatment option for severe venous and arterial thrombosis in children.

Intra-atrial tissue plasminogen activator infusion for prosthetic valve thrombosis

Thrombosis is a well-known and life-threatening complication of prosthetic mechanical valves. Therapy typically requires medical thrombolysis or surgical thrombectomy/valve replacement. We report the case of a thrombosed atrioventricular valve in a young boy with complex congenital heart disease, which was successfully treated with direct intra-atrial infusion of recombinant tissue plasminogen activator after failed attempts at systemic therapy. We present this treatment as an alternative to conventional medical therapy.

Successful thrombolysis after pulmonary embolectomy for persistent massive postoperative pulmonary embolism

Massive postoperative pulmonary embolism (PE) is associated with a poor prognosis in patients presenting with haemodynamic instability. Since recent surgery is a commonly accepted contraindication for thrombolytic therapy, pulmonary embolectomy is an appropriate therapeutic approach in these patients. If life-threatening symptoms of PE persist after pulmonary embolectomy, however, very few other therapeutic options are available. We report the successful use of locally administered low-dose thrombolysis 2 days after pulmonary embolectomy in a patient with postoperative PE and persistent severe hypoxaemia and pulmonary hypertension. During and after thrombolysis, no bleeding complications occurred. We conclude that low-dose thrombolysis for PE may be considered even in patients who have recently undergone major thoracic and abdominal surgery if embolectomy and continued intravenous heparin have failed to be successful and life-threatening symptoms of PE persist.

Thromboembolic problems after the Fontan operation

One of the major causes of morbidity and mortality after the Fontan operation is thromboembolic events (TE). To assess the current knowledge of TE after Fontan surgery, a comprehensive MEDLINE search of the English literature from 1971 to 2000 was conducted using the key words Fontan, univentricular heart, children, thrombosis, congenital heart disease, cavopulmonary, and palliation. Other relevant publications were identified from bibliographies of the literature retrieved. Fifty-one studies were identified and analyzed for incidence, potential morbidity and mortality, risk factors, prophylactic options, and risk/benefit ratio of prophylactic anticoagulation as relates to TE after Fontan surgery. There were 23 case reports, 13 retrospective cohort studies that included some details about TE among other reported outcomes after Fontan procedures, eight retrospective cohort studies in which TE was the primary outcome measure, and seven articles reporting cross-sectional point surveys, only three of which directly surveyed TE as an outcome. Based on an analysis of the current literature, there is insufficient evidence to make clear recommendations about optimal anticoagulant prophylaxis at this time. Multicenter randomized controlled trials comparing prophylactic antiplatelet with anticoagulation therapies are needed to provide rational scientific guidelines for future management of Fontan patients.

Safety and outcomes of thrombolysis with tissue plasminogen activator for treatment of intravascular thrombosis in children

OBJECTIVES

In this study, we tried to determine the safety and outcomes of thrombolysis with tissue plasminogen activator of intravascular thrombus.

STUDY DESIGN

Eighty consecutive children were treated between 1985 and 1999 in a tertiary care setting in a retrospective case series. There were 65 arterial thrombi (56 after cardiac catheterization) and 15 venous thrombi treated with tPA at an average dose of tPA of 0.5 mg/kg/hour for a median duration of 6 hours.

RESULTS

Clot resolution was complete in 65% of children, partial in 20%, and there was no effect in 15%. There were major complications in 40%, minor complications in 30%, and no complications in 30%. Two patients had cerebral ischemia secondary to hypotension because of profound bleeding, with intracranial hemorrhage in 2 additional patients. Clot resolution was not related to patient age or weight, dose, and duration of tPA therapy and fibrinogen levels. However, complications were more likely in patients who weighed less, had a longer duration of therapy, a greater decrease in fibrinogen levels, and who failed to have resolution of their clot.

CONCLUSIONS

tPA therapy can be effective in the thrombolysis of intravascular thrombus in children, but is associated with a low margin of safety and an unknown risk-benefit ratio.

Pulmonary thromboembolism after one and a half ventricle repair. Successful catheter-directed thrombolysis

Acute pulmonary thromboembolism in a patient who had undergone bidirectional Glenn anastomosis was treated by percutaneous selective intravascular thrombolysis. A 20-year-old woman was diagnosed with pulmonary stenosis and right ventricular hypoplasia, complete occlusion of the left pulmonary artery secondary to a Blalock-Taussig shunt, and atrial septal defect. The patient developed thromboembolism of the subsegmental branches of the right pulmonary artery resulting in critical hemodynamic deterioration 2 weeks after undergoing one and a half ventricle repair (bidirectional Glenn shunt). The patient was treated with tissue plasminogen activator administered directly into the right pulmonary artery via an intravascular catheter. Progressive recanalization of the obstruction began immediately. Pulmonary angiography 3 months after thrombolytic therapy demonstrated patent subsegmental vessels. Early detection of the pulmonary thromboembolism and prompt intervention are crutial to relieving this fatal complication after a Fontan operation.

Cardiopulmonary interactions in children with congenital heart disease: physiology and clinical correlates

Cardiopulmonary interaction is the term that is used to describe the inseparable connection between the heart and lungs. In health, the cardiovascular and pulmonary systems are in perfect balance. In disease, derangements of either system leads to dysfunction in the other. Physicians attempt to improve health with therapeutic interventions (positive pressure ventilation) typically aimed at treating disease (pneumonia with hypoxia) in one system (lungs) with resultant positive (recruitment of alveoli) and negative (ventilator induced lung injury) consequences and secondary impact on the other system (heart with decreased cardiac output). This manuscript will review the physiologic basis of normal cardiopulmonary interactions and the pathophysiology that occurs in specific disease processes affecting children with congenital cardiac disease. Lastly, we will present current data highlighting therapeutic interventions aimed at improving cardiopulmonary interactions.

Transcatheter coil occlusion of residual interatrial communications after Fontan procedure

OBJECTIVE

To assess the use of detachable coils as an alternative method to occlude interatrial communications after Fontan operations.

DESIGN

Descriptive clinical study of selected patients after Fontan operation with interatrial communications inappropriate for transcatheter umbrella occlusion.

SETTING

Tertiary paediatric cardiac referral centre.

PATIENTS

Seven patients after Fontan operation with residual interatrial communications of various types producing a right to left shunt.

INTERVENTIONS

Transcatheter placement of detachable coils with a diameter of 3 or 5 mm within the interatrial communication.

RESULTS

A total of 14 coils were successfully placed within persistent patent fenestrations of the interatrial baffle, residual leaks at the suture line between the patch material and the right atrial wall, and unusual venous interatrial communications. The mean (SD) aortic oxygen saturation increased from 88 (1.1)% (range 86-89%) to 92 (1.3)% (range, 89-93%; p < 0.001) and the mean (SD) right atrial pressure rose from 9.7 (2) mm Hg (range, 6-11) to 10.6 (2.4) mm Hg (range, 6-13; p < 0.05) after coil implantation. In five patients, complete obliteration of the interatrial shunt was shown by angiography after coil implantation. At a mean (SD) follow up of 10 (4) months (range, 3-15) a residual interatrial shunt was detected by Doppler colour echocardiography in only one patient, and oxygen saturations ranged from 90% to 95% (mean, 92%). There were no late coil embolisations, thromboembolic events, or haemolysis in any patient.

CONCLUSIONS

Detachable coils can be used successfully to occlude residual interatrial communications after the Fontan procedure. In selected cases, in whom intended transcatheter umbrella occlusion of residual interatrial leaks is not possible, the use of detachable coils might offer a safe alternative method to eliminate interatrial right to left shunting after the Fontan procedure.