Streptokinase treatment for femoral artery thrombosis after arterial cardiac catheterisation in infants and children

How to Avoid Arterial Access During Transcatheter Closure of Patent Ductus Arteriosus Using Anatomo-haemodynamic Landmark

Objective

To evaluate the feasibility, safety, and efficacy of transcatheter closure (TCC) of patent ductus arteriosus (PDA) using anatomo-haemodynamic landmark without any arteriography.

Method

In this prospective, non-randomized study, all consecutive patients with PDA undergoing transcatheter closure at LPS Institute of Cardiology, Kanpur, India between January 2019 and June 2024 were evaluated. TCC was performed using anatomical and haemodynamicl landmark without aortogram, and device was deployed through antegrade route only. Transthoracic echocardiography with colour-Doppler imaging was used to confirm position of the device before final deployment. Primary outcome was procedural and fluoroscopy time, and major complications (access site complications, device embolization, residual shunt ≥ grade 3, haemolysis, flow acceleration in left pulmonary artery and descending thoracic aorta, and death). Success was defined as complete closure of shunt without any major complications.

Result

TCC was successfully performed through antegrade route in 250 patients (age: 2.3 ± 1.2 years; weight: 10.3 ± 9.8 kg) while 16 patients were excluded for various reasons. Mean diameter of duct was 6.7 ± 4.5 mm. Male and female comprised 176 (70.4%) and 74 (29.6%) respectively. PDA were type A (n = 195; 78%), B (n = 27; 10.8%), C (n = 20; 8%), and (n = 8; 3.2%). TCC was successful in all patients although dislodgement was noted in 1 (0.04%). Lifetech duct occluder and Konar MFO were most commonly used devices in 156 (62.4%) and 33 (13.2%) patients respectively. Immediate closure was achieved in 233 (93.2%) patients while remaining 17 (7.8%) with grade I or II shunt on echocardiogram had complete closure in 2 days. Device embolization was observed in 1 (0.4%) patient while flow acceleration in DTA were observed in 5 (2%) patients. Procedure was successful in 99.6% using antegrade while TCC using isolated venous route was successful in 94%.

Conclusion

TCC of PDA using anatomo-haemodynamic landmark and avoiding arterial access is feasible, safe, and effective, with excellent results on short and medium-term follow-up.

Comparison of isolated venous approach with the standard approach in children undergoing patent ductus arteriosus device closure

BACKGROUND

Transcatheter device closure is a safe procedure recommended in children with patent ductus arteriosus (PDA). While the standard procedure uses arterial and venous femoral access, it poses risk of vascular complications especially in young infants. Isolated venous approach has been tried in a few studies and was found to be non-inferior to the standard technique. In this prospective observational study, we have compared the two vascular approaches of PDA device closure in pediatric patients and have also studied the feasibility of this approach in young children with weight < 6 kg.

RESULTS

PDA device occlusion was performed with either one of the approaches-venous alone (group I) or standard approach (group II) in a total of 135 children enrolled prospectively. The baseline data, procedural outcomes, vascular complications, and radiation dose were compared between the two groups. Fifty-two and 83 children were included in group I and group II, respectively. A total of 22 children (16%) (13 in group I; 9 in group II) had weight < 6 kg. In group II, 6 children (7.2%) had vascular site complications treated with heparin infusion with two children requiring thrombolysis. Another child in group II developed intravascular hemolysis following residual shunt, requiring surgical device retrieval and closure. No significant differences were observed in mean fluoroscopic time (p = 0.472) and air kerma between the two groups (p = 0.989).

CONCLUSION

Transcatheter PDA device closure without arterial access is a feasible and safe option in children including young infants. This technique avoids the risk of vascular complications although requires careful case selection.

Reperfusion Injury with Compartment Syndrome Following Systemic Thrombolysis for Cardiac Catheterization-Related Arterial Thrombosis in an Infant

Systemic thrombolysis is increasingly used for management of arterial thrombosis following cardiac catheterization, and complications apart from bleeding manifestations are not well reported. We report the case of an infant with lower limb ischemia secondary to femoral arterial thrombosis, which developed after cardiac catheterization. Systemic thrombolysis resulted in successful reperfusion of the lower limb. However, the infant subsequently developed compartment syndrome, requiring an emergent fasciotomy. This case highlights the importance of surveillance for the development of reperfusion injury-related compartment syndrome postsystemic thrombolysis for arterial thrombosis.

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.

Incidence and predictors of cardiac catheterisation-related arterial thrombosis in children

OBJECTIVE

Arterial thrombosis is one of the most reported complications of cardiac catheterisation (CC) in children. The aim of the study was to evaluate the incidence and predictors of arterial thrombosis in children with cardiac diseases (CDs).

METHODS

During 12 consecutive months, all children aged 0-19 years undergoing CC of the femoral arteries were included in this observational study. After CC, clinical evaluation of impaired limb perfusion was performed according to local guidelines. Doppler ultrasonography was performed when decreased limb perfusion was suspected.

RESULTS

123 children (30% aged <12 months, 70% aged >12 months) underwent CC. Arterial thrombosis occurred in 14 of the 123 children (11.4%). Twelve cases (12/14=86%) of arterial thrombosis occurred in infants aged <12 months and 2 (2/14=14%) in older children. Overall younger age (p<0.01, OR (95% CI) 0.49 (0.28 to 0.86)) and low body weight (p<0.004, OR (95% CI) 0.78 (0.65 to 0.92)) were significantly associated with an increased risk of arterial thrombosis. Cyanotic CD (p=0.07, OR (95% CI) 2.87 (0.90 to 9.15)) showed a trend towards increased thrombotic risk.

CONCLUSIONS

Arterial thrombosis is a common complication of CC in infants. Diagnosis of CC-related arterial thrombosis remains a challenge. Well-defined clinical monitoring protocols may be valuable methods for timely detection and treatment of arterial thrombosis.

Post-catheterisation arterial thrombosis in children--pathophysiology, prevention, and treatment

Lower limb ischaemia is the most frequent complication of cardiac catheterisation in children. It is often overlooked, but it can cause significant disability and may limit arterial access sites to repeat diagnostic or interventional catheterisations. A narrative review of the literature on arterial access site thrombosis in children was carried out with a special focus on current evidence that supports preventive and treatment strategies. Anticoagulation, thrombolysis, and thrombectomy have been used successfully to treat arterial access site thrombosis. However, it is not completely established which is the role of each treatment modality and what is the most appropriate timing to deliver it. Therefore, diagnostic and therapeutic strategies have to be prospectively investigated, particularly for clarifying the role of new pharmacologic interventions and of percutaneous and surgical thrombectomy in the current era.

Treatment of femoral artery thrombosis with streptokinase and heparin after cardiac catheterization

Background:

Thrombosis is the most common complication during cardiac catheterization via femoral artery access. Alongside heparinization, fibrinolytic therapy is recommended if there are signs of ischemia in the lower extremity.

Objectives:

Given the paucity of data in the existing literature on streptokinase (SK) therapy in pediatrics, we designed this study to assess the efficacy of SK in pediatric patients with diagnosed femoral artery thrombosis following cardiac catheterization.

Patients and Methods:

The study population initially consisted of 1788 pediatric patients who underwent cardiac catheterization via the femoral artery access. Diminished or absent pulses in the lower extremity were detected in 123 patients, 45 of whom (2.5% of 1788) required treatment and were therefore considered for the next stage of study. Treatment was comprised of post-procedural intravenous heparin, either 50 U/kg/Q4h or 10 - 20 U/kg/h continuously. After heparinization for 24 hours, if the pulse of the affected extremity was not palpable, heparin therapy was continued (heparin-treated group, n = 28), and if the symptoms of femoral artery ischemia were persistent, heparin was discontinued and intravenous SK with a loading dose of 2000 U/kg over 20 - 30 minutes was commenced (SK-treated group, n =17).

Results:

In the presence of pulselessness in the lower extremity, a maintenance dose of SK (1000 U/kg/h, during 1 - 24 hours) was intravenously administered. Regarding the return of the pulses post-therapeutically, normal and weak/absent pulses were detected in seven (25.2%) and 21 (74.8%) of the 28 patients, respectively, in the heparin-treated group (P value < 0.001), whereas normal and weak/absent pulses were detected in 15 (88.2%) and two (11.8%) of the 17 patients, respectively, in the SK-treated group (P value < 0.001).

Conclusions:

Our findings demonstrated a high success rate and a low complication rate for systemic SK therapy in femoral artery thrombosis after catheterization.

Low dose tissue plasminogen activator treatment for vascular thrombosis following cardiac catheterization in children: a single center experience

OBJECTIVES

To assess the efficacy and safety of low dose tissue plasminogen activator (tPA) therapy in children with vascular thrombosis following cardiac catheterization.

BACKGROUND

Currently, heparin is the standard of care for vascular thrombosis, however, it may not be efficacious in dissolving existing thrombi. Although tPA is an accepted thrombolytic therapy for life-threatening thrombosis in children, it is not a well-established treatment for the thrombosis of femoral vessels following cardiac catheterization.

METHODS

A retrospective analysis was performed from 1/1/2009 until 6/30/2011 at Rady Children's Hospital-San Diego (RCHSD) reviewing all cases with venous or arterial thrombosis at the vascular access site following cardiac catheterization, and a survey was conducted among the Congenital Cardiovascular Interventional Study Consortium members regarding their experience in tPA therapy.

RESULTS

At RCHSD, out of 1,155 catheterizations, 12 children developed femoral thrombosis. In three children, where 12-h heparin therapy was unsuccessful in resolving thrombosis, we used low-dose tPA according to the following regime: 0.05 mg/kg/h for 30 min, followed by 0.1 mg/kg/h for 4 h. We achieved thrombolysis in all cases evidenced by repeat ultrasound and return of palpable pulse with normal limb circulation. No complications were encountered. The survey confirmed that adult tPA dose (0.1-0.5 mg/kg/h) has 100% efficacy in resolving thrombi in children with vascular thrombosis, however, the rate of serious complications was not negligible (15%).

CONCLUSION

tPA is an efficacious therapy to dissolve thrombi that developed as a complication of cardiac catheterization in children. The rate of complications due to tPA may be reduced using a lower dose: 0.05-0.1 mg/kg/h.

The effects of ranitidine and hydrocortisone on the complications of femoral artery obstruction treated by streptokinase following cardiac catheterization in pediatric patients with congenital heart diseases

Background:

The most important complication following cardiac catheterization required urgent therapeutic management is vessel obstruction and arterial thrombosis. The morbidity following this complication can be decreased by surgery intervention and/or thrombolytic drugs.

Objectives:

In this study we evaluated the effects of ranitidine and hydrocortisone on pediatric patients with congenital heart diseases who suffered from femoral artery obstruction following cardiac catheterization on decreasing the events after streptokinase administration.

Materials and Methods:

This semi experimental study was conducted on 47 patients among 600 cases who underwent cardiac catheterization from April 2002 to December 2011.The patients suffered from distal vessel obstruction following cardiac catheterization with no response to surgery intervention, were enrolled and divided in two groups. Streptokinase was administrated in both groups. Patients in group 2 (25 cases), received ranitidine and hydrocortisone before streptokinase administration. In group 1 (22 cases), the loading dose of streptokinase was 2000IU/kg/ in 20-30 minutes/ infusion and thereafter streptokinase was administrated 1000 IU /kg/hour. In group 2, the loading dose was 3000IU/kg in 20-30 minutes /infusion and 1500 IU/kg/hour as maintenance dose. The infusion dose of streptokinase was decreased and then terminated in 2-3 hours by the time arterial pulse was detected by pulse oximetry.

Results:

There were 13 (59, 1%) male and 9 (40.9%) female patients in group 1. In group 2, there were 15 (60%) male and 10 (40%) female cases (P = 0.949). Patients in both groups were matched well regarding age, body weight, height and the duration of streptokinase infusion (P < 0.05). The incidence of hematoma was higher in group 1 than group 2 (P = 0.032). the patients of Group 1 required more blood transfusion than group 2 because the incidence of bleeding was more in the first group (P = 0.042). 12 patients in group 1 required fresh frozen plasma transfusion versus 4 patients in group 2 (P = 0.049). Local oozing was detected more in group 1 (P = 0.042). Significant bleeding was occurred in 6 cases in group 1; however this event did not occurrin any patients in group 2 (P = 0.007). Although 4 patients in group 1 suffered from anaphylactic shock after streptokinase administration but no patients in group 2 did. (P = 0.041).

Conclusions:

Based on the results of this study, we concluded that streptokinase was able to remove the vessel thrombosis at the site of cardiac catheterization and ranitidine and hydrocortisone administration before streptokinase may be effective in order to reduce the complications related to thrombolytic drugs; however the experience of the performer is an issue of concern in this matter.

Percutaneous interventions of the aorta

Coarctation of the aorta includes a wide array of anatomical and pathophysiological variations that may cause important long-term morbidity and mortality. Percutaneous techniques, such as balloon dilation and stenting, allow clinicians to safely decrease or abolish most gradients along the aorta, albeit with limitations. Proper patient selection and interventional technique allow clinicians to obtain an adequate stretch or therapeutic tear of the vessel wall, but should avoid complications, such as an excessive tear, dissection, aneurysm formation or rupture. The interventional technique is tailored by patient characteristics such as age, size and growth potential, by characteristics of the lesion such as degree of narrowing, length, angulation(s) and by local regulations.

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children.

METHODS

The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

RESULTS

We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C).

CONCLUSIONS

The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.

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).

Coarctation of the aorta: stenting in children and adults

Coarctation of the aorta may present in infants, children, or adults, and it requires treatment to prevent serious morbidity and mortality. Recent advances in equipment and a growing collective experience have made placement of balloon-expandable stents a safe and effective alternative to surgery or angioplasty in a growing range of patients. This review seeks to provide a working aid for stenting of coarctation of the aorta, based on the techniques and technical considerations in practice at our institution. Between 1989 and 2005, the Congenital Cardiovascular Interventional Study Consortium (CCISC), a consortium of 17 centers, of which our institution is the largest contributor, performed 588 stent placements for coarctation of the aorta. Of the 588 procedures, 580 (98.6%) were successful, as defined by reduction of the gradient to less than 20 mm Hg or increase of the ratio of the diameter of the coarctation area (CoA) to the diameter of the descending aorta (DAo) to at least 0.8. There were a total of 84 complications occurring in 69/588 (11.7%) cases. The most common significant complications were femoral access vessel related 15/588 (2.6%), aneurysm formation 13/588 (2.2%), aortic dissection 9/588 (1.5%), and cerebrovascular accident 6/588 (1.0%). There were two procedure-related deaths (0.3%) recorded in the 16-year period. Many of these significant complications occurred in the same patients. Balloon-expandable stents should be considered a safe and very effective treatment modality in a significant subset of patients with coarctation of the aorta.

O uso da estreptoquinase no tratamento da oclusão arterial aguda pós-cateterização da artéria femoral em crianças com menos de 10 kg

CONTEXTO: O tratamento da oclusão arterial aguda em menores de 5 kg tem constituído tema de discussão. OBJETIVOS: Avaliar o tratamento do quadro da oclusão arterial aguda pós-cateterismo da artéria femoral em crianças com menos de 10 kg com o uso de heparina isolada e também associada com estreptoquinase, e comparar os resultados do exame físico (como diagnóstico), da reversão da oclusão arterial, de complicações e de exames laboratoriais nos dois métodos MÉTODOS: Trinta casos de oclusão da artéria femoral foram identificados em 1.583 cateterismos em crianças no Instituto de Cardiologia de Porto Alegre, entre 1992 e 2000. Os pacientes foram divididos em dois grupos: um usou apenas heparina (14 casos), e o outro usou heparina associada com estreptoquinase (16 casos). Os exames laboratoriais (tempo de protrombina, tempo de tromboplastina parcial ativado e fibrinogênio) coletados antes e durante a infusão intravenosa foram avaliados estatisticamente, assim como o tempo de uso da medicação, as complicações e os resultados. RESULTADOS: O exame físico mostrou-se método fidedigno para avaliar a oclusão; no grupo que utilizou a associação de heparina e estreptoquinase, houve a resolução de 87% dos casos de oclusão arterial, e a principal complicação foi sangramento no sítio de punção em 56,3% dos pacientes. Os resultados apresentaram p < 0,05. Os exames laboratoriais não tiveram significado estatístico. CONCLUSÃO: A estreptoquinase associada com a heparina é mais efetiva do que a heparina isolada no tratamento da oclusão arterial aguda da artéria femoral pós-cateterismo, tanto que sua associação apresenta uma redução do risco relativo de 88% em relação à heparina isolada.

Brachial Artery Thrombosis in Infants: An Algorithm for Limb Salvage

BACKGROUND

Arterial occlusion in infants, although uncommon, is usually an iatrogenic event associated with arterial vascular access. Most common in the upper limb, the consequences of iatrogenic arterial occlusion may be gangrene and limb loss. Even if there is adequate collateral flow and limb loss is avoided, long-term growth disturbances may be seen. There are few published data to guide the management of arterial occlusion in premature or sick infants. In general, there is agreement regarding the importance of early diagnosis and the reestablishment of limb perfusion with the fewest risks, but the optimal choice and timing of treatment modalities remain unknown.

METHODS

This article examines the authors' experiences at the Royal Children's Hospital, Melbourne, and provides their algorithm for the management of this complex iatrogenic disease.

RESULTS

The management algorithm has successfully treated 11 limbs in 11 patients with arterial vascular access-associated thrombosis over the period 1995 to 2003, with no instances of limb loss. Five of these patients required surgical intervention.

CONCLUSIONS

The authors recommend a multidisciplinary approach involving plastic surgeons and hematologists for all cases of suspected or confirmed arterial thrombosis. A consensus algorithm that determines the role of heparin, thrombolysis, and acute surgical interventions, and the sequence of such interventions, is useful in providing the framework of therapy. The early recognition of the limb at risk is a key factor in obtaining a successful outcome.

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).

Arterial complications following cardiac catheterization in children less than 10 kg

We sought to determine if a higher dose of heparin would reduce arterial complications in patients weighing 10 kg or less undergoing cardiac catheterization to investigate congenital heart disease. Sixty patients were given either 100 (group A) or 150 (group B) IU x kg(-1) of heparin in a double-blinded randomized manner. Initial arterial access was established using a 4F cannula in all patients. Mean activated clotting time measured 20 minutes following heparin administration was significantly lower in group A than in group B (199 versus 251 seconds). Only 3 out of 60 patients (5%) required treatment for loss of femoral pulse. The age, weight, activated clotting time, length of catheterization procedure, time taken to establish arterial access, and the duration of arterial cannulation were comparable between the groups. Weight under 4 kg, age under 1 month, and cannula size larger than 4F were identified as independent risk factors for the development of arterial complications. Arterial access using a 4F cannula is a safe procedure in children weighing 10 kg or less. The incidence of significant arterial complications is low, and they do not appear to be preventable by a higher dose of heparin.

Management of an absent pulse following arterial catheterization

Arterial cannulation is a common procedure for diagnostic as well as interventional catheterisation. The incidence of arterial damage varies from around 1% to 45 % depending on the size of the patient, size of catheters used, repeat procedures, pre-existing vascular disease and whether the procedure was interventional as opposed to diagnostic (twelve times higher risk with intervention). The absence of a pulse following catheterisation can result from spasm, local thrombus formation, formation of a flap of endothelium, dissection or avulsion of the artery. In order to minimize the risks of arterial damage the following factors may help: a clean puncture, small French catheters, tapered well-fitting introducer sheaths, a short procedure time and administration of heparin (50 to 100 units/kg with further dose/s if the procedure lasts more than 75 minutes).

Percutaneous transluminal angioplasty for the treatment of complete arterial occlusion after retrograde cardiac catheterization in infancy

Nine patients with arterial thrombosis were treated with transcatheter recanalization and subsequent balloon dilation of the occluded vessel. Repeat angiography or duplex sonography 3 to 14 months after intervention showed completely patent arteries without restenosis in 7 patients; there was residual narrowing of the vessel in the remaining 2 patients.

Acute complications in the current era of therapeutic cardiac catheterization for congenital heart disease

The acute complications of therapeutic cardiac catheterization for congenital heart disease as performed currently in a small unit were reviewed. In recent years, there has been a significant increase in the number of lesions thought amenable to catheter therapy. Only a few reports, however, have addressed the overall incidence of acute complications of therapeutic cardiac catheterization, all representing the experience of centres performing moderate-to-large numbers of procedures. A retrospective review was performed of 425 therapeutic catheter procedures performed at our institution between May 1993 and November 1997. Acute complications were retrieved from the database. This included all adverse events that were clinically recognized at the time of or within 2 weeks after the procedure and which, to the best of the authors' clinical judgement, were related to the catheterization and not part of the natural history of the child's illness. All patients were observed overnight following the procedure, and stayed in hospital if a complication developed. There were 49 acute complications (11.5%), of which 43 (10.1%) were deemed minor and 6 (1.4%) were considered major. The rate was low in patients with valvar pulmonary stenosis, including three neonates (3/45, 6.7%), for those undergoing angioplasty of native co-arctation (1/15, 6.7%) and pulmonary arteries (2/27, 7.4%); and for coil embolization of systemic to pulmonary collateral arteries (1/16, 6.3%). The rate was high in patients with valvar aortic stenosis, including 12 neonates (9/37, 24.3%), and for angioplasty of re-coarctation (4/23, 21.7%). There were more overall complications in neonates (25.6%) than in older patients (10.1%) (p < 0.01). Two patients died (0.5%), but no patient required emergency surgical intervention. In spite of the introduction of many new therapeutic modalities with greater intrinsic risk, and the fact that patients with more complex lesions and who are more acutely ill are being treated, the overall rate of complications remains relatively low. This probably reflects improvements in pericatheterization medical management, in selection of patients, in procedural techniques, and in the experience of operators.

Predictors of arterial thrombosis after diagnostic cardiac catheterization in infants and children randomized to two heparin dosages

Arterial thrombosis is the most frequent major complication of percutaneous arterial catheterization in children. We prospectively studied the effect of randomized dosage of heparin, 50 IU/kg-group I and 100 IU/kg-group II, on the incidence of arterial thrombosis in 366 children and analysed the various factors which may influence the occurrence of this complication. The age of patients ranged from 17 d to 11 yr (mean age 39.5 +/- 40.9 mo) and mean weight was 11.2 +/- 7.8 kg (range 3 to 39 kg). The incidence of arterial thrombosis was 9.8% in group I and 9.3% in group II (P = NS). There was no statistical difference in precatheterization and procedure variables in the two groups and also in the group with absent pulse (n = 35) to the group with pulse present post cath (n = 331). There were 24.9% infants in our study and 14.3% of these had arterial thrombosis. The loss of pulse was more often seen with more number of attempts at arterial puncture (P < 0.001), absence of back bleed at the end of the procedure (P < 0.001), and increased duration of catheterization (P < 0.01). Use of larger sheath size in a given weight and body surface area of children increased incidence of arterial thrombosis. The administration of heparin 50 IU/kg was equally efficacious to heparin 100 IU/kg. Of the patients with arterial thrombosis, 23 responded with intravenous heparin and 12 needed streptokinase. There was no bleeding or haematoma. Thus our study shows that less attempt for arterial puncture, use of smaller sheath size, maintaining shortest procedure time and ensuring back bleed minimises incidence of arterial thrombosis post catheterization.

Rational approach to use of heparin during cardiac catheterization in children

OBJECTIVES

We sought to determine an anticoagulation protocol for use during cardiac catheterization in children.

BACKGROUND

There are few data to indicate which dose of heparin represents adequate anticoagulation or how best to monitor its efficacy. In this study, adequate anticoagulation was defined as the amount of heparin needed to prevent a significant increase in serum fibrinopeptide A, a sensitive marker for thrombin activity. The degree of heparinization was estimated by the activated clotting time.

METHODS

Thirty-six children (1 month to 19.5 years old) with congenital heart disease underwent diagnostic cardiac catheterization; 13 of these 36 patients had an additional interventional procedure. Sheaths and catheters were flushed with heparinized saline (1 IU/ml); during the procedure, 33 of the 36 patients received either a 50- or a 100-IU/kg heparin bolus. Paired fibrinopeptide A and activated clotting time samples were obtained throughout each procedure.

RESULTS

Increasing the activated clotting time with heparin resulted in a dose-related decrease in fibrinopeptide A levels. A single heparin bolus of either 50 or 100 IU/kg elevated the activated clotting time above baseline level (209 +/- 52 s after 50 IU/kg, 270 +/- 57 s after 100 IU/kg vs. 133 +/- 20 s at baseline [p < 0.0001]) and reduced fibrinopeptide A levels below baseline (7.9 +/- 14 ng/ml after 50 IU/kg, 4.8 +/- 3.7 ng/ml after 100 IU/kg vs. 38 +/- 59 ng/ml at baseline [p < 0.0001]). Heparin flush alone did not increase the activated clotting time above baseline and failed to suppress an increase in fibrinopeptide A levels. There were no differences in activated clotting time and fibrinopeptide A values between patients undergoing diagnostic or interventional procedures.

CONCLUSIONS

Administration of a heparin bolus to maintain an activated clotting time > 200 s prevented a significant increase in thrombin activity. Heparin flush alone did not provide adequate anticoagulation. Patients undergoing an interventional procedure did not require more heparin than that needed for a diagnostic procedure.

Magnetic resonance imaging of the iliofemoral arteries after balloon dilation angioplasty of aortic arch obstructions in children

BACKGROUND

We wished to determine the nature and incidence of changes in the iliofemoral arteries after balloon dilation angioplasty (BDA) for aortic arch obstruction in children and to determine the reliability of gradient magnetic resonance imaging (MRI) in their detection.

METHODS AND RESULTS

Sixty-three children, including 62 with and 1 without arch obstruction, underwent MRI of the iliofemoral vessels. Of these, 36 patients had undergone transfemoral BDA (7 after previous transfemoral diagnostic catheterization), 12 had undergone diagnostic transfemoral catheterization but not BDA, and 15 had no history of femoral arterial catheterization. The iliofemoral arteries were normal on MRI in all 15 children without catheterization. Among the 36 children who had undergone BDA, the ipsilateral iliofemoral artery was normal in 15, mildly narrowing in 7, and severely stenotic or occluded in 14 (39%), including 6 of 9 patients treated for acute femoral artery thrombosis and 8 with no history of femoral artery thrombosis. Two patients had documentation of progressive obstruction. Six patients had concordant conventional angiography. There was a significant correlation between the number of balloon catheters used for the angioplasty and severe occlusive changes. Nine of 19 patients who had undergone diagnostic transfemoral catheterization had severe obstructive changes on MRI; 8 of 9 weighed < 10 kg at catheterization.

CONCLUSIONS

Obstructive lesions of the iliofemoral arteries are common after transfemoral BDA of arch obstructions (58%) and can be reliably evaluated with gradient MRI. Catheter size and manipulation are the main contributing factors.

Thrombolytic therapy in infants and children

Thrombolytic therapy is being increasingly used to treat various cardiac and other disorders in the pediatric population. The use of thrombolytic therapy in thrombosis following cardiac catheterization, aortic thrombosis, right atrial and caval thrombosis, pulmonary embolism, thrombosed prosthetic valves, thrombosed Blalock-Taussig shunts, and other disorders is delineated. Special issues of the newborn are discussed. A wider appreciation of the indications and contemporary experience would help in optimizing the use of thrombolytic therapy in children.

Tissue plasminogen activator (alteplase) treatment for femoral artery thrombosis after cardiac catheterisation in infants and children

OBJECTIVE

To determine the efficacy of fibrinolytic therapy with tissue plasminogen activator (alteplase) in infants and children with arterial thrombosis after cardiac catheterisation.

DESIGN

Use of alteplase (Actilyse) in a protocol with prospective data collection. Alteplase was administered to infants and children with arterial thrombosis after cardiac catheterisation. A dose of 0.5 mg/kg/h was given continuously via a peripheral vein for the first hour followed by 0.25 mg/kg/h till clot lysis occurred or treatment had to be stopped because of bleeding complications.

SETTING

University hospital, intensive care unit.

PATIENTS

17 consecutive infants and children with femoral artery thrombosis after cardiac catheterisation between 1 April 1988 and 31 October 1991.

MAIN OUTCOME MEASURE

Reopening of the vessel.

RESULTS

Complete clot lysis was achieved in 16 of 17 patients within 4-11 hours after the start of treatment. In one patient only partial lysis occurred. After complete lysis rethrombosis developed in one patient 15 hours after the end of treatment. Bleeding complications were seen in nine patients. These were restricted to the arterial puncture site, except for one who showed mild epistaxis. Three patients had to be treated with packed erythrocytes.

CONCLUSIONS

Alteplase was an effective treatment of arterial thrombosis after cardiac catheterisation in infants and children. Further studies are needed to determine whether lower doses will reduce the frequently observed bleeding complications.

Balloon angioplasty for aortic recoarctation in children: initial and follow up results and midterm effect on blood pressure

OBJECTIVE

To assess the direct and follow up results of balloon angioplasty for aortic recoarctation with respect to the type of initial operation and to determine the midterm effect on systolic blood pressure.

DESIGN

Prospective study of invasive haemodynamic and angiographic data and non-invasive data on upper body blood pressure.

SETTING

Tertiary referral centre for paediatric cardiology.

SUBJECTS

24 infants and children (age 0.3-16.2 years, mean 5.9 years) who had had surgical correction for coarctation (end to end anastomosis (14 patients) subclavian flap angioplasty (nine), patch angioplasty (one)).

MAIN OUTCOME MEASURES

Peak systolic gradient over the recoarctation and aortic diameters before and directly after angioplasty and at follow up. Upper body blood pressure before and after angioplasty and at latest follow up.

RESULTS

Mean peak systolic gradient initially decreased from 35 (15) to 12 (9) mm Hg (p < 0.001) and was 9 (10) mm Hg at follow up after 1.4 (0.5) years. Patients with a subclavian flap repair showed a slight further decrease in the residual gradient at follow up (p < 0.05). The coarctation diameter increased from 5.3 (2.6) to 7.7 (2.5) mm (p < 0.001), and a further increase to 9.3 (2.9) mm (p < 0.01) was present at follow up after 1.4 (0.5) years without significant changes in other aortic diameters. Upper body systolic blood pressure decreased from 138 (24) to 115 (17) mm Hg after balloon angioplasty, and the effect on blood pressure persisted at a mean follow up of 3.7 years. One patient died of ventricular failure. Femoral artery thrombosis occurred in three patients. In one patient a small aneurysm occurred that had not increased at follow up. In one patient restenosis after angioplasty was redilated successfully. In one patient dilatation of a residual stenosis after angioplasty failed.

CONCLUSION

Balloon angioplasty for recoarctation is effective and is associated with accelerated growth of the dilated segment at follow up in many patients. The complication rate is acceptable. Midterm follow up shows persistent relief of upper body hypertension in most patients.

Short- and midterm results of balloon valvuloplasty for valvular aortic stenosis in children

During a 27-month period, 21 consecutive children (aged 0.1 to 15.7 years) with isolated valvular aortic stenosis underwent percutaneous transfemoral balloon valvuloplasty. Ten children had undergone earlier surgical valvulotomy. The indication for treatment was ST-T-segment changes at rest or during bicycle-ergometry, a continuous-wave Doppler-derived transvalvular gradient greater than 60 mm Hg or syncope, or a combination. Mean peak systolic left ventricular pressure decreased from 165 +/- 19 to 131 +/- 19 mm Hg (p less than 0.001). Mean end-diastolic left ventricular pressure did not change significantly (12 +/- 3 vs 11 +/- 5 mm Hg). Mean peak systolic valve gradient decreased from 71 +/- 23 to 22 +/- 11 mm Hg (p less than 0.001). Mean cardiac index remained unchanged (2.9 +/- 0.8 vs. 3.0 +/- 0.7 liters.min-1.m-2). Aortic valve regurgitation on angiography appeared or increased in 9 patients (up to grade 3 in 3 children). Noninvasive follow-up studies were performed for 2 to 4.2 years (mean 2.8). ST-T changes on the electrocardiogram at rest or during exercise were present in 6 patients before balloon valvuloplasty and had disappeared in all at 6-month follow-up. Reoccurrence of ST-T changes after a longer follow-up was associated with severe valve regurgitation. Syncope was not observed after balloon valvuloplasty. The continuous-wave Doppler gradient decreased from 94 +/- 36 to 49 +/- 15 mm Hg (p less than 0.001). After a follow-up of 2 to 4.2 years (mean 2.8) it remained unchanged (43 +/- 13 mm Hg; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Countercurrent aortography: an alternative to cardiac catheterization in infancy

Countercurrent aortography via a peripheral artery was used to clarify the aortic arch anatomy in 25 infants in whom cross-sectional and Doppler evaluation was inconclusive. Ages ranged from 3 days to 11 months (median 9 days), and 80% were neonates. The suspected diagnosis was aortic coarctation in 21 infants, interrupted aortic arch in two, recoarctation in one, and vascular ring in one. A countercurrent aortogram provided adequate diagnostic information in 24 infants. A diagnosis of coarctation was confirmed in 15, interruption of the aortic arch in two, and vascular ring in one. In six infants countercurrent aortography excluded the presence of anomalies of the aortic arch. In only one infant, who had an anomalous origin of the right subclavian artery from the descending aorta, did this technique fail to provide adequate information. The only complication observed was transient ischemia of the arm in one patient. Countercurrent aortography is a minimally invasive procedure that can provide adequate angiographic information without the need for cardiac catheterization in patients with inconclusive echocardiographic evaluation. Injection into a right upper limb artery is preferred, because it gives better opacification of the ascending and transverse aortic arch than injection into a left one.