In utero arterial embolism from renal vein thrombosis with successful postnatal thrombolytic therapy

In utero arterial thrombosis treated with recombinant tissue plasminogen activator in an infant of a diabetic mother: A case report and literature review

A 36+5 days' gestation infant of a diabetic mother suffered arterial thrombosis with severe vascular occlusions in multiple limbs, especially of the left upper extremity. Although the mechanism remains elusive, the association between venous and arterial thrombi in infants and diabetic mothers has previously been established. Cases typically result in the amputation of the dysvascular limbs. In the present case, the use of selective angiography to administer recombinant tissue plasminogen activator allowed the left upper extremity to be salvaged with amputation of only the left thumb.

Thrombosis in the critically ill neonate: incidence, diagnosis, and management

Among children, newborn infants are most vulnerable to development of thrombosis and serious thromboembolic complications. Amongst newborns, those neonates who are critically ill, both term and preterm, are at greatest risk for developing symptomatic thromboembolic disease. The most important risk factors are inflammation, DIC, impaired liver function, fluctuations in cardiac output, and congenital heart disease, as well as exogenous risk factors such as central venous or arterial catheters. In most clinically symptomatic infants, diagnosis is made by ultrasound, venography, or CT or MRI angiograms. However, clinically asymptomatic vessel thrombosis is sometimes picked up by screening investigations or during routine imaging for other indications. Acute management of thrombosis and thromboembolism comprises a variety of approaches, including simple observation, treatment with unfractionated or low molecular weight heparin, as well as more aggressive interventions such as thrombolytic therapy or catheter-directed revascularization. Long-term follow-up is dependent on the underlying diagnosis. In the majority of infants, stabilization of the patients’ general condition and hemodynamics, which allows removal of indwelling catheters, renders long-term anticoagulation superfluous. Nevertheless, in certain types of congenital heart disease or inherited thrombophilia, long-term prophylaxis may be warranted. This review article focuses on pathophysiology, diagnosis, and acute and long-term management of thrombosis in critically ill term and preterm neonates.

[In utero thrombosis of neonates: inherited thrombophilia?]

Thromboembolic events are relatively uncommon in childhood. It involves mainly children under one year of age and adolescents, with an incidence is 5.1/10000 live births. Authors present a course of disease of seven cases with neonatal thromboembolic events (2.5/admissions), diagnosed and treated at the Neonatal Division of Department of Pediatrics. In three of seven cases thrombosis proved to be of intrauterine origin. In each of the latter cases, inherited thrombophilia of the mothers was detected. Additional risk factors including infection could be revealed only in one case. Using in vivo and post mortem DNA analysis, mother-like-thrombophilia could not be confirmed in any of the newborns. Based on their experiences, authors suppose that undetected predisposing factors added to maternal thrombophilia can be considered as etiological factor. Authors suggest the intensive follow-up of pregnant women with thrombophilia and also their fetuses.

Antithrombotic therapy in neonates and children: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This chapter about antithrombotic therapy in neonates and children is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs, and Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading, see Guyatt et al in this supplement, pages 123S-131S). In this chapter, many recommendations are based on extrapolation of adult data, and the reader is referred to the appropriate chapters relating to guidelines for adult populations. Within this chapter, the majority of recommendations are separate for neonates and children, reflecting the significant differences in epidemiology of thrombosis and safety and efficacy of therapy in these two populations. Among the key recommendations in this chapter are the following: In children with first episode of venous thromboembolism (VTE), we recommend anticoagulant therapy with either unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1B]. Dosing of IV UFH should prolong the activated partial thromboplastin time (aPTT) to a range that corresponds to an anti-factor Xa assay (anti-FXa) level of 0.35 to 0.7 U/mL, whereas LMWH should achieve an anti-FXa level of 0.5 to 1.0 U/mL 4 h after an injection for twice-daily dosing. In neonates with first VTE, we suggest either anticoagulation or supportive care with radiologic monitoring and subsequent anticoagulation if extension of the thrombosis occurs during supportive care (Grade 2C). We recommend against the use of routine systemic thromboprophylaxis for children with central venous lines (Grade 1B). For children with cerebral sinovenous thrombosis (CSVT) without significant intracranial hemorrhage (ICH), we recommend anticoagulation initially with UFH, or LMWH and subsequently with LMWH or vitamin K antagonists (VKAs) for a minimum of 3 months (Grade 1B). For children with non-sickle-cell disease-related acute arterial ischemic stroke (AIS), we recommend UFH or LMWH or aspirin (1 to 5 mg/kg/d) as initial therapy until dissection and embolic causes have been excluded (Grade 1B). For neonates with a first AIS, in the absence of a documented ongoing cardioembolic source, we recommend against anticoagulation or aspirin therapy (Grade 1B).

Catheter-directed thrombolysis of inferior vena cava thrombosis in a 13-day-old neonate and review of literature

Complete inferior vena cava thrombosis (IVC) in neonates is uncommon, but may cause significant morbidity. A 13-day-old neonate suffered IVC thrombosis secondary to antithrombin III deficiency, possibly contributed to by a mutation in the methyl tetrahydrofolate reductase gene. Catheter-directed thrombolysis (CDT) with recombinant tissue plasminogen activator (rt-PA, Alteplase) was used successfully to treat extensive venous thrombosis in this neonate without complications. We also review the literature on CDT for treatment of IVC thrombosis in critically ill neonates and infants.

Renal outcome of neonatal renal venous thrombosis: review of 28 patients and effectiveness of fibrinolytics and heparin in 10 patients

OBJECTIVES

Neonatal renal venous thrombosis is a rare disorder that can result in severe renal damage. To evaluate the experience over 10 years and review the effectiveness of fibrinolytic and/or heparin therapy, chart reviews were performed for newborns with renal venous thrombosis. PATIENTS, INTERVENTIONS, AND OUTCOME MEASURES: Twenty-eight newborns with renal venous thrombosis were treated at Children's Hospitals and Clinics of Minnesota and Fairview University Medical Center from 1991 to 2001.

RESULTS

Unilateral involvement was noted in 25 neonates (89%) and bilateral involvement in 3 (11%). Unilateral renal venous thrombosis affected mostly term infants, whereas 2 of 3 infants with bilateral renal venous thrombosis were <32 weeks' gestational age (birth weight: 745-1505 g). One mother had antiphospholipid syndrome. Of 11 neonates evaluated for congenital thrombophilia, 1 had the factor V Leiden mutation. Ten neonates received either unfractionated or low molecular weight heparin for 3 days to 7 months. Three infants with unilateral renal venous thrombosis treated with heparin alone did not seem to benefit from such therapy. Seven neonates were treated with fibrinolytics and unfractionated heparin (4 neonates with unilateral renal venous thrombosis and 3 with bilateral renal venous thrombosis). Treatment with fibrinolytics did not result in restoration of renal function in the 4 neonates with unilateral renal venous thrombosis but was associated with return of almost normal function in the 2 neonates with bilateral renal venous thrombosis who received fibrinolytics immediately after renal venous thrombosis diagnosis. Two neonates treated with fibrinolytics suffered bleeding complications at the area of adrenal hemorrhage. Two neonates (not treated for renal venous thrombosis) died as a result of underlying disease.

CONCLUSIONS

Most neonatal renal venous thrombosis is unilateral and does not respond to fibrinolytic therapy and heparin. The use of fibrinolytics may prevent chronic renal failure in neonates with bilateral renal venous thrombosis if begun within 24 hours of diagnosis. Fibrinolytic therapy, however, is associated with a risk of bleeding, specifically if there is an associated adrenal hemorrhage.

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.

Forearm compartment syndrome in the newborn: report of 24 cases

PURPOSE

Isolated cases of ischemia, compartment syndrome, or Volkmann's ischemic contracture in the forearm of the newborn infant have been reported in the past. The purpose of this study is to review a large series of patients with neonatal forearm compartment syndrome and to report the important clinical features.

METHODS

A search of medical records from 1980 to 2000 identified 24 children with evidence of ischemia of the forearm at the time of birth. Records and images were reviewed for prenatal and birth history, maternal factors, medical conditions, pattern of involvement, treatment, and outcomes. Patients were grouped according to the extent of initial soft-tissue involvement.

RESULTS

All patients presented with a sentinel forearm skin lesion. Patterns of involvement ranged from mild skin and subcutaneous lesions to dorsal and volar compartment syndrome with or without distal tissue loss. Early treatment intervention was limited to a single case in which the diagnosis of compartment syndrome was made and an emergency fasciotomy was performed with a good outcome. In other cases tissue loss, compressive neuropathy, muscle loss, and late skeletal changes were responsible for impaired function. Distal bone growth abnormality was common.

CONCLUSIONS

Forearm compartment syndrome in the newborn is not as uncommon as previously thought. The skin lesion was the common, salient, initial diagnostic finding. Early diagnosis and appropriate referral led to the salvage of a functional limb in 1 of the patients in this series. The severity of the initial insult correlated with the degree of impairment in growth and function. The delayed diagnosis and treatment of an evolving compartment syndrome may compromise further final function.

Antithrombotic Therapy in Children*

This article about antithrombotic therapy in children is part of the 7th American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh the risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this article are the following. In neonates with venous thromboembolism (VTE), we suggest treatment with either unfractionated heparin or low-molecular-weight heparin (LMWH), or radiographic monitoring and anticoagulation therapy if extension occurs (Grade 2C). We suggest that clinicians not use thrombolytic therapy for treating VTE in neonates, unless there is major vessel occlusion that is causing the critical compromise of organs or limbs (Grade 2C). For children (ie, > 2 months of age) with an initial VTE, we recommend treatment with i.v. heparin or LMWH (Grade 1C+). We suggest continuing anticoagulant therapy for idiopathic thromboembolic events (TEs) for at least 6 months using vitamin K antagonists (target international normalized ratio [INR], 2.5; INR range, 2.0 to 3.0) or alternatively LMWH (Grade 2C). We suggest that clinicians not use thrombolytic therapy routinely for VTE in children (Grade 2C). For neonates and children requiring cardiac catheterization (CC) via an artery, we recommend i.v. heparin prophylaxis (Grade 1A). We suggest the use of heparin doses of 100 to 150 U/kg as a bolus and that further doses may be required in prolonged procedures (both Grade 2 B). For prophylaxis for CC, we recommend against aspirin therapy (Grade 1B). For neonates and children with peripheral arterial catheters in situ, we recommend the administration of low-dose heparin through a catheter, preferably by continuous infusion to prolong the catheter patency (Grade 1A). For children with a peripheral arterial catheter-related TE, we suggest the immediate removal of the catheter (Grade 2C). For prevention of aortic thrombosis secondary to the use of umbilical artery catheters in neonates, we suggest low-dose heparin infusion (1 to 5 U/h) (Grade 2A). In children with Kawasaki disease, we recommend therapy with aspirin in high doses initially (80 to 100 mg/kg/d during the acute phase, for up to 14 days) and then in lower doses (3 to 5 mg/kg/d for > or = 7 weeks) [Grade 1C+], as well as therapy with i.v. gammaglobulin within 10 days of the onset of symptoms (Grade 1A).

Multiple arterial thrombi and in utero leg gangrene in an infant of a diabetic mother

This case report is of an infant of a diabetic mother who presented with lower extremity gangrene occurring in utero that necessitated a below the knee amputation at 3 hours of age. The association of venous thrombi in infants of diabetic mothers (IDMs) has been firmly established. However, in this case the thrombi were arterial and resulted in gangrene during the second trimester of gestation. The reason for the increased tendency to develop thrombi in infant of diabetic mothers has not been elucidated. We did an extensive workup of this infant to look for a cause of the arterial thrombus. The only abnormality found was in the plasminogen activity, which was significantly lower than the reference values for infants of the same gestational and chronological age. The significance of this finding on the propensity of IDMs to develop thrombi is discussed.

Renal vein thrombosis: a 10-year review

PURPOSE

Renal vein thrombosis (RVT) is a rare cause for pediatric surgical consultation. The purpose of this study is to review the Montreal experience in the 1990s with RVT.

METHODS

A retrospective chart review was conducted from 1990 through 1999.

RESULTS

Twenty-three cases were identified by Duplex ultrasound scan. Mean length of follow-up was 42 months. Eighty-three percent (83%) of cases were diagnosed within the first month of life. In utero thrombosis was suspected in 22% and was associated with caval thrombosis and factor V Leiden. Known risk factors were present in 87%. The "diagnostic triad" of flank mass, gross hematuria, and thrombocytopenia was present in only 13% at the time of diagnosis. Long-term renal function impairment was detected in 100% of those who did not receive heparin, and in 33% of those who did receive heparin. No patient required dialysis. One patient required nephrectomy for recurrent pyelonephritis.

CONCLUSIONS

RVT occurs more commonly than anticipated. Because the "classic" triad of signs usually is absent at presentation, the presence of either a flank mass, hematuria, or thrombocytopenia in a patient with risk factors should prompt investigation for RVT. Factor V Leiden is a risk factor for in utero RVT. Anticoagulation improves renal outcome. Patients with RVT require long-term follow-up.

Evaluation and treatment of thrombosis in the neonatal intensive care unit

Thromboses are infrequent but serious complications of patients in the NICU. Thromboses tend to occur in very sick neonates, particularly preterm neonates, and the majority of such thromboses are related to central vascular catheters. Other risk factors for neonatal thromboses include infants of diabetic mothers, sepsis, small for gestational age, congenital heart disease, maternal antiphospholipid syndrome, and possibly inherited prothrombotic disorders. Appropriate treatment, dosage, and duration of therapy for neonatal thromboses has not been studied in clinical trials. Treatment options include observation, anticoagulation, thrombolysis, and surgical thrombectomy. Regardless of the treatment chosen, all neonates with thromboses require frequent reassessment of the thromboses by angiography, echocardiography, or ultrasound until thrombus resolution occurs.

Intrauterine vascular deficiency of the upper limb

We report six cases of intrauterine vascular deficiency of the upper limb, presenting over a 12-year period, with established areas of necrosis at the time of birth. Three of the six mothers were diabetic. An urgent examination of the neonate should be done to exclude occult systemic thomboses, as early anticoagulation or thrombolytic therapy may be indicated. The majority of cases were managed conservatively with dressings and splintage of the limb; exceptionally surgical intervention was required. Long-term sequelae included flexion contractures and shortening of the forearm bones.

Recombinant tissue plasminogen activator for neonatal and pediatric vascular thrombolytic therapy

Thrombotic vascular occlusion may complicate the clinical course of many neonatal and pediatric pathologic processes. Systemic thrombolytic therapy with heparin, urokinase, or streptokinase may not be appropriate in the critically ill neonate because these agents generate a diffuse coagulopathic state. Direct surgical intervention for repair may be precluded by the small size of the vessels involved. Recombinant tissue plasminogen activator (rTPA) induces only a minimal proteolytic state while inducing thrombolysis within the local environment of the clot. We report our experience with regional rTPA infusion in four critically ill patients with venous and arterial thrombotic disorders. there were two brachial artery occlusive lesions--a neonate with iatrogenic occlusion due to a misplaced intravenous catheter and a 2-year-old child with inadvertent arterial ligation during an attempted venous cutdown. Two venous lesions consisted of a full-term neonate with renal vein/inferior vena caval thrombosis and a 32-week infant with partial superior vena caval thrombosis due to a Broviac catheter. Systemic thrombolytic therapy was contraindicated in these patients because of underlying illnesses. Pretherapy vascular evaluation included Doppler examination and angiography. The rTPA infusion was continued until there was evidence of clot lysis by ultrasound, angiogram, or venogram. Infusion rate of rTPA was adjusted according to fibrinogen levels. All three neonates responded successfully to rTPA therapy. Two neonates required only bolus administration and one responded to combined bolus and continuous infusion therapy after 58 hours. rTPA failed to reverse brachial artery occlusion in the 2-year-old child with purpura fulminans.(ABSTRACT TRUNCATED AT 250 WORDS)

High-dose urokinase therapy in newborn infants with major vessel thrombosis

The effectiveness of urokinase therapy for thrombosis in children, particularly in newborn infants, has not been established. We report our experience with the local administration of high-dose intrathrombus urokinase in two newborn infants. One infant had aortic thrombosis and the other, thrombosis of the right femoral artery. The known abnormalities in the newborn's fibrinolytic mechanism provide the rational basis for the therapeutic use of high doses of plasminogen activators. No significant abnormalities of our patients' fibrinolytic systems were found, and effective thrombolysis was achieved. A literature review of the use of urokinase therapy for thrombosis in children reveals great disparities in dosage and outcome. We believe that fixed-dose regimens should be replaced by individually adjusted thrombolytic therapy and that the need for higher doses of urokinase in newborns should be studied further.