Late complications after femoral artery catheterization in children less than five years of age

Five-Year Outcomes of Coarctoplasty with Stents in the Pediatric Population: Results from a Retrospective Single-Center Cohort with Centrally Adjudicated Outcomes

Transcatheter stent implantation is a widely performed procedure for treating native coarctation of the aorta (CoA) in pediatric patients. However, data on mid- to long-term outcomes are limited. The aim of this study was to evaluate the mid-term safety and efficacy of transcatheter CoA stenting based on centrally adjudicated outcomes. This retrospective cohort study included patients aged 15 years or younger undergoing de novo stenting for CoA or recoarctation (reCoA) between 2006 and 2017. Immediate and 5-year outcomes were assessed. Immediate outcomes (procedural and in-hospital) were retrieved from electronic records. Rates of 5-year reCoA, stent fractures, aneurysmal/pseudoaneurysmal formation, and all-cause mortality were mid-term outcomes. The study included 274 patients (64% male and 36% female) with a median (interquartile range) age of 9 (6-12) years. Procedural success was achieved in 251 patients (91.6%). Procedural complications occurred in 4 patients (1.4%), consisting of stent migration in 1 (0.3%) and small non-expanding non-flow-limiting aortic wall injuries in 3 (1.1%). Major vascular access complications were observed in 18 patients (6.6%), acute limb ischemia in 8 (2.9%). In-hospital mortality occurred in 4 patients (1.4%). Five-year cumulative incidence rates of stent fractures, reCoA, and aortic aneurysmal/pseudoaneurysmal formation were 17/100 (17%), 73/154 (48%), and 8/101 (7.92%), respectively. Of 73 reCoAs, 47 were treated with balloon angioplasty, and 15 underwent a second stent implantation. Five-year all-cause mortality occurred in 4/251 (1.6%) patients. Coarctoplasty with stents was safe and effective in our pediatric population during a 5-year follow-up despite a high rate of reCoA.

Autologous and synthetic pediatric iliofemoral reconstruction: a novel technique for pediatric iliofemoral artery reconstruction

Pediatric lower extremity arterial catheterization-related injuries can result in significant long-term morbidity. Revascularization is challenging due to concerns for long-term patency and growth accommodation with synthetic grafts. We describe a novel technique for iliofemoral revascularization using common iliac artery transposition and bridging polytetrafluoroethylene grafts. We treated two children who underwent femoral catheterization resulting in lifestyle-limiting claudication. Both patients experienced immediate resolution of symptoms. Postoperative imaging demonstrated widely patent vasculature. ASPIRE (autologous and synthetic pediatric iliofemoral reconstruction) is a method of pediatric iliofemoral artery revascularization that allows for an autologous artery to span the hip joint, reducing graft thrombosis risk and accommodating patient growth.

Pediatric arterial thrombosis: A single-institution cohort study of patient characteristics and thrombosis outcomes

BACKGROUND

Arterial thrombosis (AT) is an increasingly recognized complication in pediatrics. Consensus clinical practice guidelines suggest immediate removal of the indwelling arterial catheter and a short course (5-7 days) of anticoagulation. The optimal duration and modality of antithrombotic therapy in children are yet to be determined.

AIMS

Describe treatment patterns and outcomes in pediatric patients with AT and explore predictors for complete thrombus resolution or long-term complications.

METHODS

Single-institution retrospective study. Patients were identified by ICD-9 and ICD-10 codes for the diagnosis of AT or reports of AT on ultrasound from January 1, 2012, to October 1, 2022. Descriptive and logistic regression analyses were used.

RESULTS

101 patients were included. The median age was 2.2 months. The most common underlying diagnoses were congenital heart disease (39.6%) and infection (22.8%). A majority of patients had symptomatic thrombosis in an extremity, and 78% were catheter-associated. 81% of patients received anticoagulation with a median duration of 35 days. Out of the 70 patients who were treated with anticoagulation alone and had a follow-up imaging, 70% had complete resolution after 90 days of anticoagulation. No clear predictors of complete resolution were identified. Eighteen patients had long-term sequelae secondary to arterial insufficiency. Those with infection-associated AT were more likely to have long-term complications. The major and clinically relevant non-major bleeding rate was 11%.

CONCLUSION

Duration of anticoagulation was widely variable, and 70% of patients achieved complete resolution by 90 days of anticoagulation. A significant proportion of patients developed long-term sequelae secondary to arterial insufficiency. Sepsis/infection at the time of diagnosis with AT was more likely to be associated with long-term complications.

Practice patterns in the management of pediatric iliofemoral arterial thrombosis

BACKGROUND

Acute arterial thrombosis can be life- and limb-threatening. Most pediatric patients with iliofemoral arterial thrombosis are treated successfully with medical therapy; however, expert consensus is limited, and many recommendations are based on the extrapolation of adult data. We aim to understand treatment patterns and long-term outcomes after pediatric acute iliofemoral arterial thrombosis, from which management recommendations can be informed.

METHODS

A single-institution retrospective study of pediatric patients diagnosed with iliofemoral arterial thrombosis from 2009 to 2018 was performed. Multiple parameters of management and follow-up were evaluated. Children anticoagulated for ≤28 days versus >28 days were compared. Data analysis used Fisher exact and Mann-Whitney U tests.

RESULTS

Two hundred thirty-six children were included. Median age at diagnosis was 65 days (interquartile range 17-163), with 207 diagnosed as infants, 15 diagnosed between 1 to 2 years, and 14 diagnosed between 2 to 16 years. The median treatment duration was 28 days (interquartile range 13-42); patients treated for >28 days had a longer time for thrombus resolution, and more follow-up ultrasounds were performed. Limb length discrepancy did not differ between the groups (1.0% vs 6.3%, P = .06), and no patients were documented to have developed peripheral arterial disease over a median 6.5-year follow-up. Multiple treatment strategies were employed, the most common being heparin bridged to enoxaparin (25.0%) and enoxaparin monotherapy (21.6%). Eight patients (3.4%) underwent surgical intervention.

CONCLUSION

Pediatric iliofemoral arterial thrombosis is primarily a disease of infants treated adequately with heparin or enoxaparin, infrequently requires surgical intervention, and is rarely associated with long-term complications. When guided by thrombus resolution on ultrasound, a four-week or shorter course of anticoagulation does not increase the need for surgical intervention or long-term complications.

Pediatric venoarterial and venovenous ECMO

Extracorporeal membrane oxygenation (ECMO) is an invaluable resource in the treatment of critically ill children with cardiopulmonary failure.  To date, over 36,000 children have been placed on ECMO and the utilization of this life saving treatment continues to expand with advances in ECMO technology.  This article offers a review of pediatric ECMO including modes and sites of ECMO cannulation, indications and contraindications, and cannulation techniques.  Furthermore, it summarizes the basic principles of pediatric ECMO including circuit maintenance, nutritional support, and clinical decision making regarding weaning pediatric ECMO and decannulation.  Finally, it gives an overview of common pediatric ECMO complications including overall mortality and long-term outcomes of ECMO survivors. The goal of this article is to provide a comprehensive review for healthcare professionals providing care for pediatric ECMO patients.

Outcomes of Catheter-Related Arterial and Venous Thrombosis After Enoxaparin Therapy in Neonates and Infants With Congenital Heart Disease

OBJECTIVES

Outcomes of catheter-related arterial and venous thrombosis after enoxaparin therapy in neonates and infants with congenital heart disease.

DESIGN

A single-center retrospective cohort study.

SETTING

Cardiac ICU.

PATIENTS

Patients under 1 year old cared for in the cardiac ICU at Nicklaus Children's Hospital from January 2015 to January 2019 and treated with enoxaparin for central vascular catheter-related arterial and venous thrombosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred fifty-six events of central catheter-related arterial and venous thrombosis were included in the study. Arterial thrombi accounted for 109 (69.9%) and venous thrombi for 47 (30.1%) of the events. Femoral vessels were the most commonly affected site (88.5%). Therapeutic outcomes were analyzed in 106 events, excluding those without follow-up imaging. The analysis was stratified by age into neonates and infants and catheter types into arterial and venous catheter groups. Therapeutic dose of enoxaparin was higher in neonates (median 1.8 mg/kg/dose) compared with infants (1.6 mg/kg/dose; p = 0.001). Complete resolution was seen in 68%, partial resolution in 19%, nonresolution in 13% of the events. The complete resolution was higher for arterial than venous (85% vs 65.6%; p = 0.032) thrombi with a shorter duration of enoxaparin treatment (23 vs 43 d; p = 0.014). Complete resolution was lowest in neonates with venous thrombosis (42.9%). The median time to complete resolution by Kaplan-Meier analysis was 24.9 days in the overall cohort, 34.3 days in neonates, 24.9 days in infants, 20 days in arterial, and 44.9 days in venous catheter group.

CONCLUSIONS

A high proportion of vascular catheter-related thrombi identified in infants with congenital heart disease resolve with enoxaparin treatment. In all patients with thrombosis, arterial versus venous thrombosis is associated with greater odds of resolution.

Low profile sheaths in pediatric neurointervention: a multicenter experience

BACKGROUND

Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population.

METHODS

All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced.

RESULTS

From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05).

CONCLUSION

The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Patient Characteristics and Treatment Outcomes of Symptomatic Catheter-Related Arterial Thrombosis in Infants: A Retrospective Cohort Study

OBJECTIVE

To describe the clinical characteristics, outcomes, and adverse events of treatment for symptomatic infant catheter-related arterial thrombosis.

STUDY DESIGN

Single-center retrospective medical record review of 99 infants (age <365 days) with catheter-related arterial thrombosis, either following indwelling arterial catheter placement or cardiac catheterization, who were treated with anticoagulation over an 8-year span at a pediatric tertiary care center. Outcomes measured include thrombosis progression, bleeding events, and thrombus resolution following the treatment period.

RESULTS

Thromboses were secondary to indwelling arterial catheter placement in 51 (51.5%) and cardiac catheterization in 48 (48.5%). The median age at diagnosis of catheter-related arterial thrombosis was 52 days. All patients received therapeutic anticoagulation with either unfractionated heparin or low molecular weight heparin for a maximum of 28 days. Progression of catheter-related arterial thrombosis occurred in 8 (8.1%) patients. One (1%) major and 3 (3%) minor bleeding events occurred within the cohort. Complete thrombus resolution was observed in 60 (60.6%), partial resolution in 33 (33.3%), and no resolution in 6 (6.1%) following the treatment period. Factors associated with complete thrombus resolution included time from intervention to catheter-related arterial thrombosis diagnosis (median of 1 day vs 5 days in those who experienced thrombus resolution vs those who did not, P = .035), and iliac and/or femoral artery involvement (P = .015).

CONCLUSIONS

Our treatment approach to infant catheter-related arterial thrombosis is safe and effective. Limitations of the study are its retrospective nature with a limited number of patients from a single institution. Additional prospective studies are needed to determine the optimal treatment approach to catheter-related arterial thrombosis in infants.

Direct percutaneous transcarotid approach for embolization of dural sinus malformation in a premature neonate: A case report

CONCLUSIONS

Direct percutaneous TCAA can be a feasible access for intracranial interventions in neonates with LBW and unavailable UA access.

Use of radial access sheaths for transfemoral neuroendovascular procedures in children

PURPOSE

Pediatric neuroendovascular procedures require special considerations. Given small vessel sizes, risk for arterial injury must be weighed against use of larger devices, with the diameter of the sheath being a known association with arterial complications. We recently transitioned to using thin-walled radial sheaths for transfemoral angiography in children, given their lower profile. Here, we report on these sheaths' technical success and complications, comparing against a historical cohort where regular vascular sheaths were employed.

METHODS

We retrospectively recorded patient and procedural data from 168 consecutive procedures from September 2017 to January 2019 when radial-specific sheaths were exclusively used at our tertiary pediatric hospital. These results were compared to data from September 2015 to January 2017, when regular vascular sheaths were exclusively used in 152 consecutive procedures. Statistical analysis was performed using unpaired t test or chi-square test, with p < 0.05 considered statistically significant.

RESULTS

Patient characteristics (age, sex, weight) were not statistically different between the case and control group. No significant differences were found in the procedural data with the exception of heparin use which was higher in the radial-sheath cohort. There was a decrease in the rate of complications in the case group (1.2%) versus control group (2.6%), though not statistically different.

CONCLUSION

Radial-specific sheaths have numerous beneficial characteristics that make them well-suited to the pediatric population. In our study, we show that radial sheaths are equally effective and safe perioperatively. Follow-up research may show if radial sheaths used transfemorally decrease long-term complications such as limb-length discrepancy and mortality.

Microsurgical vascular bypass in the setting of pediatric limb length discrepancy

Management of pediatric iatrogenic arterial occlusions can be challenging clinically, leading to chronic complications such as claudication and limb length discrepancy. We report the case of a 6-month-old female patient who had experienced iatrogenic right external iliac and common femoral arterial occlusion. At the age of 8 years, she had developed claudication and a limb length discrepancy of 3.2 cm. She underwent common iliac artery to superficial femoral artery and profunda artery bypass via a branched autologous reverse great saphenous vein using microsurgical techniques for the distal anastomoses. In the present report, we have focused on the musculoskeletal improvements, benefits of microsurgery in pediatric vessels, and maximization of epiphyseal perfusion.

Dual-layer everted saphenous vein patch for pediatric femoral artery repair following ECMO decannulation

Decannulation from pediatric veno-arterial extracorporeal membrane oxygenation (VA-ECMO) involves the removal of large arterial perfusion cannulas from relatively small lower extremity arteries. While these challenging repairs are frequently performed by general pediatric surgeons, there is little standardization with regard to vascular techniques within the pediatric surgery training paradigm, resulting in variability in the repair of these arteriotomies and potential future consequences for lower extremity perfusion and growth. Herein we present a technique for repair of large common femoral arteriotomies following removal of ECMO perfusion cannulas utilizing a dual-layer patch of ipsilateral saphenous vein harvested via the arterial cutdown incision. This vein segment is everted to maximize endothelial surface area of the patch and dual layered to provide additional support against aneurysmal degeneration. The described technique is an effective repair of arteriotomy following VA-ECMO decannulation, which minimizes vascular complications and is an accessible technique to those without advanced vascular surgical training. LEVEL OF EVIDENCE: Level IV; operative technique description with small case series.

Natural history of acute pediatric iliofemoral artery thrombosis treated with anticoagulation

OBJECTIVE

Acute iliofemoral artery thrombosis (IFAT) can occur in critically ill neonates and infants who require indwelling arterial cannulas for monitoring or as a consequence of cardiac catheterization. Guidelines suggest treatment with anticoagulation, but evidence supporting the optimal duration of therapy and the role of surveillance ultrasound is limited. The objectives of this study were to characterize the kinetics of thrombus resolution and to define an appropriate duration of anticoagulation and interval for surveillance ultrasound.

METHODS

This was a single-center retrospective cohort study of pediatric patients with acute IFAT from 2011 to 2019. Medical records and vascular laboratory studies were reviewed. Patients with one or more surveillance ultrasound examinations were included. Thrombus resolution was defined as multiphasic flow throughout the index limb without evidence of echogenic intraluminal material by ultrasound. Time to resolution of thrombus was assessed using Kaplan-Meier analysis.

RESULTS

Fifty-four limbs in 50 patients were identified with acute IFAT. The median age was 9.9 weeks (interquartile range, 3.1-21.7 weeks), with a median weight of 4.2 kg (interquartile range, 3.3-5.5 kg). The majority of limbs (65%) with acute IFAT presented with a diminished pedal Doppler signal, commonly after cardiac catheterization (55%). Forty-eight (89%) limbs had complete arterial occlusion on index ultrasound, and flow could not be detected below the ankle in 48%. The median number of ultrasound examinations per limb was three (range, two to seven), and 61% of limbs had a surveillance ultrasound within 7 days of diagnosis. At 14 and 30 days, 33% and 64% of patients, respectively, treated with anticoagulation had an estimated complete resolution of thrombus. Nine (17%) patients did not receive anticoagulation, and only two of these patients experienced IFAT resolution. At the time of diagnosis, one patient underwent open thrombectomy because of a contraindication to anticoagulation, and one patient was treated with thrombolysis. There were no instances of tissue loss or amputation CONCLUSIONS: Management of IFAT with anticoagulation resulted in successful short-term outcomes. Based on the observed rate of resolution, management should start with anticoagulation, followed by surveillance ultrasound at 2-week intervals. With treatment by anticoagulation, resolution can be expected to occur in one-third of patients every 2 weeks.

Different unfractionated heparin doses for preventing arterial thrombosis in children undergoing cardiac catheterization

BACKGROUND

The role of cardiac catheterization in pediatrics has progressed significantly over the last two decades, evolving from a primary diagnostic tool to a primary treatment modality in children with congenital heart disease. Vascular complications, particularly arterial thrombosis, are among the most common unwanted post-cardiac catheterization events. In 1974, unfractionated heparin proved to be superior to placebo in decreasing the incidence of arterial thrombosis in pediatric patients. However, the optimal dose of unfractionated heparin to be utilized in this setting remains a matter of controversy. This is an update of the review first published in 2014.

OBJECTIVES

To evaluate the use of low-dose (< 100 units/kg) versus high-dose (≥ 100 units/kg) unfractionated heparin administered as an intravenous bolus at the time of initiation of cardiac catheterization (that is, immediately after arterial puncture), with or without subsequent heparin maintenance doses, for the prevention of post-procedural arterial thrombosis in children.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 15 October 2019. We planned to undertake reference checking of identified trials to identify additional studies. No language restrictions were applied.

SELECTION CRITERIA

We included randomized or quasi-randomized trials that compared low dose to high dose unfractionated heparin administered prior to cardiac catheterization. We selected studies conducted in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

The first screening of potentially eligible studies was conducted by one of the authors (MLA). The second screening, risk of bias assessment and data extraction were independently conducted by two authors (MLA, LRB). Outcomes (thrombotic events, bleeding complications, other complications) were treated as dichotomous variables. The effect measures used were risk ratio (RR), risk difference (RD) and number needed to treat (NNT), with 95% confidence intervals (CI). We assessed the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We identified no new studies for inclusion in this review. In total, two studies with a total of 492 participants were included. We had concerns about risk of bias for one of the two studies. The certainty of the evidence for our key outcomes was downgraded to moderate due to risk of bias concerns and imprecision. The confidence interval for the risk of arterial thrombotic events was compatible with benefits of either high or low unfractionated heparin dose regimens (RR low-dose versus high-dose 1.06, 95% CI 0.58 to 1.92). Only one of the studies reported the frequency of bleeding events and found no clear difference in the incidence of major or minor bleeding events between arms (RR low-dose versus high-dose 2.96, 95% CI 0.12 to 71.34 for major bleeding events; RR low-dose versus high-dose 1.38, 95% CI 0.46 to 4.13 for minor bleeding). This study also reported on the incidence of deep vein thrombosis when comparing the high versus low dose of heparin and reported a non-significant difference (RR low-dose versus high-dose 0.34, 95% CI 0.01 to 8.28). The other study lacked information about bleeding. Additional side effects of heparin other than bleeding events were not reported in either of the studies.

AUTHORS' CONCLUSIONS

Due to the limitations of the current evidence, small number of included studies, and lack of details reported in one study, we are unable to determine the effects of different dosing regimens of unfractionated heparin for the prevention of vascular thrombosis during cardiac catheterization in children. Further adequately powered, randomized clinical trials are needed.

Vascular Reconstruction in a Neonate after Iatrogenic Injury during Cardiac Catheterization

As technology and interventional techniques continue to evolve, both the volume and complexity of cardiac catheterizations will increase, leading to a rise in the number of complications. One of the most morbid complications of cardiac catheterization is vascular injury. We report the case of a 31-day-old, 3.0-kg infant with hypoplastic left heart syndrome who experienced a left common iliac artery disruption during cardiac catheterization resulting in a retroperitoneal hemorrhage. The extent of the vascular injury combined with the vessel caliber posed a technically challenging surgical scenario. Ultimately, the vascular supply to the left lower extremity was reconstructed by the plastic surgery team with a reverse autologous vein graft. To our knowledge, this multidisciplinary approach with the involvement of plastic surgery represents a unique case.

Arterial reconstructions for chronic lower extremity ischemia in preadolescent and adolescent children

OBJECTIVE

Chronic lower extremity ischemia in pediatric patients is uncommon. The intent of this study was to better define the arterial reconstructive options and their long-term durability in preadolescent and adolescent children having clinically relevant arterial occlusions affecting the lower extremity.

METHODS

The medical records of 33 consecutive pediatric patients who underwent lower extremity revascularization for chronic ischemia at the University of Michigan from 1974 to 2016 were reviewed. Patients were categorized by age, clinical manifestation, surgical intervention undertaken, and outcomes.

RESULTS

Operative treatments involved 26 preadolescent children (mean age, 6.1 years; range, 3-9 years) and 7 adolescent children (mean age, 13.9 years; range, 10-17 years). Occlusions were due to earlier injury related to catheter (14), cannula (2), or both catheter and cannula (14); penetrating trauma (2); and vasculitis (1). Preoperative manifestations included symptomatic extremity ischemia (25), growth retardation manifested by documented limb length discrepancies (21), and scoliosis (5). Primary arterial reconstructions were delayed after the precipitating vascular event an average of 5.3 and 11.2 years in the preadolescent and adolescent children, respectively. Primary procedures involved revascularizations of 36 extremities (in preadolescents and adolescents) including autologous vein (26/5), polyethylene terephthalate (Dacron; 1/0), and expanded polytetrafluoroethylene (0/3) bypasses and vein patch angioplasty (0/1). Vein grafts traversing the abdominal cavity (15) were wrapped with a synthetic mesh. Excluding one early graft occlusion, there were no major early postoperative complications after the primary procedures. Secondary operations followed 31% of the primary operations, being performed an average of 8.8 and 6.7 years later (in 8 preadolescent and 3 adolescent children, respectively) for late graft occlusions (6), graft stenoses (3), aneurysmal vein grafts (2), and anastomotic pseudoaneurysm (1). The unassisted primary graft patency rate was 69%, and the assisted secondary graft patency rate was 94%. Symptomatic ischemia resolved in all but two children. Mean postoperative ankle-brachial indices improved to 1.08 from 0.76 preoperatively. Among children having postoperative documentation of limb lengths, the limb length discrepancies became less (11), were unchanged (1), or progressed (3). Follow-up averaged 8.0 years. There was no operative mortality in this experience.

CONCLUSIONS

Primary lower extremity arterial reconstructions in children with chronic lower extremity ischemia can be successfully undertaken with excellent results. Nevertheless, the potential for late primary graft failures, evident in nearly a third of this experience, mandates careful long-term follow-up and may necessitate secondary interventions to maintain satisfactory outcomes.

The impact of femoral arterial thrombosis in paediatric cardiac catheterisation: a national study

BACKGROUND

Previous studies have identified risk factors for femoral arterial thrombosis after paediatric cardiac catheterisation, but none of them have evaluated the clinical and economic significance of this complication at the population level. Therefore, we examined the national prevalence and economic impact of femoral arterial thrombosis after cardiac catheterisation in children.

METHODS

Patients⩽18 years of age who underwent cardiac catheterisation were identified in the 2003-2009 Kids' Inpatient Database. Patients were stratified by age as follows: <1 year of age or 1-18 years of age. The primary outcome was arterial thrombosis of the lower extremity during the same hospitalisation as cardiac catheterisation. Propensity score matching was used to determine the impact of femoral arterial thrombosis on hospital length of stay, cost, and mortality.

RESULTS

Among the 11,497 paediatric cardiac catheterisations identified, 4558 catheterisations (39.6%) were performed in children <1 year of age. This age group experienced a higher prevalence of reported femoral arterial thrombosis, compared with children aged 1-18 years (1.3 versus 0.3%, p<0.001). After matching, femoral arterial thrombosis in children <1 year of age was associated with similar mortality (5.4 versus 1.8%, p=0.28), length of stay (8 versus 5 days, p=0.11), and total hospital cost ($27,135 versus $28,311, p=0.61), compared with absence of thrombosis.

CONCLUSIONS

Femoral arterial thrombosis is especially prevalent in children <1 year of age undergoing cardiac catheterisation. Clinicians should be vigilant in monitoring femoral arterial patency in neonates and infants after cardiac catheterisation.

Natural History of Iatrogenic Pediatric Femoral Artery Injury

BACKGROUND

Iatrogenic femoral artery trauma complicates the course of critically ill neonates and children. Complications from persistent arterial occlusion may include claudication and limb length discrepancies. Data supporting risk factors for such and need for revascularization are lacking.

METHODS

Review of a prospectively maintained database at a tertiary institution of iatrogenic pediatric femoral artery injuries incurred between 2013 and 2014 was performed. Additional injuries were identified by review of pediatric arterial duplex performed between 2008 and 2013. Demographics, risk factors, and outcomes were queried. Data analysis utilized Fischer's exact t-test and logistic regression.

RESULTS

Seventy-six patients were identified of which 68 presented with acute limb ischemia (ALI) and 8 with chronic iliofemoral arterial occlusion resulting in claudication (n = 6) or limb length discrepancy (n = 2). Mean weight at injury was 6.3 kg; mean age at injury was 49 weeks (50% aged <3 months). Mean follow-up was 14 months (out to 11 years). Six patients required surgery for ALI, and 6 required delayed operation for limb length discrepancy (n = 4) or for persistent external iliac artery (EIA) occlusion. Mean age at delayed revascularization was 6 years (range: 2-13 years). Vasopressor use, mechanism/location of injury, and concomitant venous thrombosis were not significantly correlated with need for operation; trends suggested that cardiac catheterization and EIA thrombosis may correlate with chronic disease. Increased age at injury was associated with need for operation.

CONCLUSIONS

Although a majority of children with ALI may be successfully treated medically, 9% will require operation for ALI and 16% ultimately required revascularization during follow-up. Persistent iliofemoral arterial thrombosis is a likely risk factor for limb length discrepancy with growth; identifying risk factors for this and improved methods for surveillance requires ongoing investigation.

Vascular trauma

Last century saw a marked increase in vascular injuries and their treatment has been improved from the experience gained in the major conflicts in the latter half of the last century. This trend of increasing numbers of vascular injuries has been perpetuated by a rise in civilian violence.

This article reviews the mechanisms, diagnosis and treatment of vascular injury and outlines some of the advances in endovascular techniques for treating vascular trauma.

Long-Term Outcome of Catheter-Related Arterial Thrombosis in Infants with Congenital Heart Disease

OBJECTIVES

To investigate the long-term outcome of catheter-related arterial thrombosis in children.

STUDY DESIGN

Data from clinical and radiologic long-term follow-up of infants with congenital heart disease developing arterial thrombosis following femoral catheterization are presented.

RESULTS

Ninety-five infants with radiologically proven arterial thrombosis because of cardiac catheter (n = 52; 55%) or indwelling arterial catheter (n = 43; 45%) were followed for a median time of 23.5 months (IQR 13.3-47.3). Overall, radiologic complete thrombus resolution was observed in 64 (67%), partial resolution in 8 (9%), and no resolution in 23 (24%) infants. Complete resolution was significantly more frequent in infants with indwelling arterial catheter-related thrombosis compared with cardiac catheter-related thrombosis (P = .001). Patients with complete resolution had a significantly lower blood pressure difference and increased ankle-ankle index compared with patients with partial or no resolution (P < .0001). However, symptoms of claudication were present only in 1 case and clinical significant legs growth retardation (≥ 15 mm) was present in 1%.

CONCLUSIONS

A significant percentage of persistent occlusion is present in children with arterial catheter-related thrombosis on long-term follow-up. In these children, the magnitude of leg growth retardation is small and possibly not clinically relevant. However, in children with congenital heart disease, the high prevalence of persistent arterial occlusion may hamper future diagnostic and/or interventional catheterization.

[LIMB LENGH SHORTENING AFTER ARTERIAL CANNULATION IN INFANCY]

OBJECTIVES

The aim of this study was to assess the relationship between arterial cannulations and the development of limb length discrepancies in childhood or impaired growth of the proximal femur.

MATERIAL AND METHODS

A retrospective study was conducted on 300 children who required arterial cannulation and/or cardiac catheterisation during childhood in relation to congenital heart diseases. Seven of these patients were referred from the Paediatric Cardiology clinic due to a limb length discrepancy and/or proximal femoral deformities.

RESULTS

Seven children, with a mean age of 10 years, were referred to our clinic. The mean length discrepancy was 2.7cm, and was more frequent on the right side. Three of the patients presented with proximal femoral deformities: two cases of caput valgum and one of bilateral physeal arrest of the greater trochanter. All children were initially treated with a shoe lift in the shortest limb. One of them required a tibial lengthening and two others are awaiting a similar procedure.

CONCLUSION

We recommend clinical and radiological follow-up of patients who have undergone catheterisation during their infancy due to the relationship between these techniques and the risk of developing a limb length discrepancy.

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.

Outcomes using a clinical practice pathway for the management of pulse loss following pediatric cardiac catheterization

OBJECTIVE

Objectives To describe the results of a clinical practice pathway (CPP) for the management of postcatheterization pulse loss in a children's hospital.

BACKGROUND

Standardized approaches to the diagnosis and management of postcatheterization arterial thrombus are lacking. As a result, substantial practice variation exists.

METHODS

Data collected prospectively for quality improvement purposes were retrospectively reviewed.

RESULTS

Since initiation of the CPP, 93/1,672 (5.4%) catheterizations resulted in pulse loss at a median patient age and weight of 73 days (1 day-5.8 years) and 4.8 kg (2-14.1 kg). Arterial thrombus was documented by ultrasound (US) in 85. Of these, 66 resolved by 12 weeks of therapy, seven patients died, and four were lost to follow-up before completing treatment. Eight patients had persistent thrombus despite a full treatment course (89% success rate in those able to complete treatment). Of patients treated with unfractionated heparin as initial therapy, 46% (17/37) achieved a therapeutic partial thromboplastin time within 12 hr with 19% (67/343) of all levels therapeutic. As a result, the CPP was modified to use enoxaparin as first line agent, of which 57% (41/72) had a therapeutic anti-Xa level after the 2nd dose and 88% by the 4th dose. No bleeding complications were observed. A priori established process metrics were achieved.

CONCLUSIONS

A CPP utilizing early initiation of anticoagulation and US to aid diagnosis of postcatheterization arterial thrombus and response to therapy is feasible and effective. In those able to complete up to 12 weeks of treatment, resolution occurs in nearly 90%. © 2014 Wiley Periodicals, Inc.

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.

Different unfractionated heparin doses for preventing arterial thrombosis in children undergoing cardiac catheterization

BACKGROUND

The role of cardiac catheterization in pediatrics has progressed significantly over the last two decades, evolving from a primary diagnostic tool to a primary treatment modality in children with congenital heart disease. Vascular complications, particularly arterial thrombosis, are among the most common unwanted post-cardiac catheterization events. In 1974, unfractionated heparin proved to be superior to placebo in decreasing the incidence of arterial thrombosis in pediatric patients. However, the optimal dose of unfractionated heparin to be utilized in this setting remains a matter of controversy.

OBJECTIVES

To evaluate the use of low-dose (< 100 units/kg) versus high-dose (≥ 100 units/kg) unfractionated heparin administered as an intravenous bolus at the time of initiation of cardiac catheterization (that is, immediately after arterial puncture), with or without subsequent heparin maintenance doses, for the prevention of post-procedural arterial thrombosis in children.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10). The authors searched MEDLINE, EMBASE, and the Virtual Health Library. Clinical trials databases and sources of grey literature were searched. No language restrictions were applied.

SELECTION CRITERIA

Randomized or quasi-randomized trials that compared low dose to high dose unfractionated heparin administered prior to cardiac catheterization were included. We selected studies conducted in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

The first screening of potentially eligible studies was conducted by one of the authors (MLA). The second screening, quality assessment and data extraction were independently conducted by two authors (MLA, LRB). Outcomes (thrombotic events, bleeding complications, other complications) were treated as dichotomous variables. The effect measures used were risk ratio (RR), risk difference (RD) and number needed to treat (NNT), with 95% confidence intervals (CI).

MAIN RESULTS

Two studies with a total of 492 participants were eligible for inclusion. Risk of bias was low for all domains in one of the studies and unclear for the other. One of the trials was stopped early. The quality of evidence for our key outcomes was moderate. The CI for the risk of arterial thrombotic events was compatible with benefits of either high or low unfractionated heparin dose regimens (RR low-dose versus high-dose 1.06, 95% CI 0.58 to 1.92). Only one of the studies reported the frequency of bleeding events for the cohort of patients and found no statistically significant difference in the incidence of major and minor bleeding events between arms (RR low-dose versus high-dose 1.38, 95% CI 0.46 to 4.13 for minor bleeding; RR low-dose versus high-dose 2.96, 95% CI 0.12 to 71.34 for major bleeding events). This study also reported on the incidence of deep vein thrombosis when comparing the high versus low dose of heparin and reported a non-significant difference (RR low-dose versus high-dose 0.34, 95% CI 0.01 to 8.28). The other study lacked information about bleeding. Side effects of heparin other than bleeding complications were not reported in either of the studies.

AUTHORS' CONCLUSIONS

Due to the limitations of the current evidence, small number of included studies, and lack of details reported in one study, we are unable to determine the effects of different dosing regimens of unfractionated heparin for the prevention of vascular thrombosis during cardiac catheterization in children. A further adequately powered, randomized clinical trial is needed.

Limb length shortening associated with femoral arterial lines in the neonatal period

Two cases involving toddlers who presented with limb length shortening and radiological findings consistent with growth plate arrest are presented. Both cases had been cared for in the neonatal intensive care unit because of extreme prematurity, and both cases had a femoral arterial line inserted on the side of the body with the short limb. This complication has not been previously described in the preterm population.

Radiofrequency catheter ablation for dyssynchrony-induced dilated cardiomyopathy in an infant

The relationship between accessory pathway-mediated ventricular preexcitation and left ventricular dyssynchrony-induced dysfunction has been described in patients with Wolff-Parkinson-White (WPW) syndrome in the absence of sustained supraventricular tachycardia (SVT). Supraventricular tachycardia in infants is usually successfully suppressed with antiarrhythmic medications, but catheter ablation has ultimately been required as definitive treatment in medically resistant cases. Catheter ablation has not been described in young infants for dyssynchrony-related dilated cardiomyopathy in the absence of SVT. We describe a case of an infant with WPW who did not have sustained supraventricular tachycardia, but who developed rapid progression of ventricular dysfunction after birth. Preexcitation could not be medically suppressed but was successfully ablated. This was followed by complete resolution of ventricular dysfunction within 2 months.

Arterial closure device to achieve hemostasis in children following percutaneous femoral arterial puncture

BACKGROUND

Percutaneous arterial closure devices have increasingly entered clinical practice to assist in achieving femoral arterial access site hemostasis. Prior studies have demonstrated the safety and efficacy of several arterial closure devices in adults.

OBJECTIVE

To evaluate the efficacy of using an arterial closure device in children.

MATERIALS AND METHODS

A retrospective review of all children (defined as younger than 18 years) undergoing device-assisted closure of their percutaneous femoral arterial access site was conducted. Patient demographics, the clinical indications for use of the arterial closure device and pre-procedural laboratory parameters were noted. The accessed common femoral artery diameter and largest procedural sheath size were recorded. The technical success rate for device deployment and rates of immediate and delayed complications including hemorrhage, access site or retroperitoneal hematoma, access site infection, arterial thromboembolism, pseudoaneurysm or arteriovenous fistulae were documented.

RESULTS

Between June 2009 and June 2011, an arterial closure device was deployed with intent to achieve hemostasis in percutaneous femoral arterial access punctures in 38 consecutive children. The mean common femoral artery diameter was 0.70 ± 0.13 cm. Device deployment was technically successful in 37/38 (97.4%) procedures. There was a single complication (2.6%), a small access site hematoma. No other immediate or delayed complications occurred.

CONCLUSION

The use of a percutaneous arterial closure device can be an efficacious method for achieving immediate femoral arterial access site hemostasis with few complications in children who have undergone percutaneous femoral arterial access procedures.

Addressing challenges in 4 F and 5 F arterial access for neurointerventional procedures in infants and young children

BACKGROUND

Among the technical challenges involved in safely performing neuroendovascular procedures in infants are limitations on the size of femoral arterial access catheters. Restricting groin access to 4 F and 5 F systems constrains the range of procedures that can potentially be performed.

METHODS AND RESULTS

We present here a consecutive series of transfemoral angiographic procedures in children with no permanent and one transient case of groin morbidity related to femoral access. We illustrate two strategies for using 4 F and 5 F systems for interventions in a manner that enables such techniques as balloon assisted coil embolization and the deployment of triaxial catheter systems to be used.

CONCLUSIONS

Extremely low groin morbidity is achievable using rigorous parameters around femoral catheterization in children. With creative approaches to working within the limitations of the access vessel size, complex endovascular neurointerventions are possible, even in the youngest infants.

Infant cardiac CT angiography with 64-slice and 256-slice CT: comparison of radiation dose and image quality using a pediatric phantom

Background

The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age.

Methodology/Principal Findings

Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocardiogram-gated helical (RGH) and prospectively electrocardiogram-gated axial (PGA) techniques in 64-slice and 256-slice CT scanners. The thermoluminescent dosimeters (TLD) were used for direct organ dose measurement, while dose-length product and effective mAs were also used to estimate the patient dose. For image quality, noise and signal-to-noise-ratio (SNR) were assessed based on regions-of-interest drawn on the reconstructed CT images, and were compared with the proposed cardiac image quantum index (CIQI). Estimated dose results were in accordant to the measured doses. The NG scan showed the best image quality in terms of noise and SNR. The PGA scan had better image quality than the RGH scan with 83.70% dose reduction. Noise and SNR were also corresponded to the proposed CIQI.

Conclusions/Significance

The PGA scan protocol was a good choice in balancing radiation exposure and image quality for infant cardiac CTA. We also suggested that the effective mAs and the CIQI were suitable in assessing the tradeoffs between radiation dose and image quality for cardiac CTA in infants. These results are useful for future implementation of dose reduction strategies in pediatric cardiac CTA protocols.

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.

Femoral artery catheterization in neonates and infants

OBJECTIVE

To determine the incidence of perfusion-related complications associated with indwelling femoral artery monitoring catheters in neonates and infants following introduction of a 2.5-F diameter, 5-cm length, polyethylene catheter (Cook Medical, Bloomington, IN) to our unit.

DESIGN

Prospective observational cohort study.

SETTING

Pediatric cardiac intensive care unit in a university-affiliated children's hospital.

PATIENTS

All patients <2 yrs old with an indwelling femoral artery catheter during a 3-yr period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred eighty-two patients (including 98 neonates), median (range) age 10 wks (0.1-84), weight 4.1 kg (2.0-11.1) were enrolled; outcomes in 249 were evaluable. Pulse strength in dorsalis pedis arteries and pulse discrepancies between feet were assessed hourly by the cardiac intensive care unit nurse and recorded on a flow sheet. Nonpalpable pulses were assessed as "absent" or "present" with ultrasonic Doppler. Following removal of the catheter, assessments of pulse strength continued until resolution of any discrepancies. Median (range) duration of catheterization was 4 days (1-23). Catheters of 2.5-F diameter were used in 227 patients and larger catheters in 55 patients. The incidence of pulse strength discrepancies between feet was 20%, loss of pulse was 3.4% (6.7% in neonates, 1.4% in older infants) when extracorporeal membrane oxygenation patients were excluded, and resolution of pulse discrepancy or loss was 100%. Duration of catheterization and use of a catheter larger than 2.5 Fr were significant predictors of loss of pulse.

CONCLUSIONS

Loss of pedal pulse distal to small-bore monitoring femoral artery catheters in neonates and infants is directly related to the duration of catheterization and is less frequent when 2.5-F, 5-cm polyethylene catheters are used instead of larger catheters.

Transcatheter closure of the arterial duct without arterial access

OBJECTIVE

To evaluate the safety and efficacy of transcatheter occlusion of the arterial duct without femoral arterial catheterization.

BACKGROUND

Patent arterial ducts have been closed percutaneously since the 1960s. It remains standard practice to use arterial access for aortography before, during, and after implantation of the device. Femoral arterial catheterisation has well recognised complications, and should be avoided unless absolutely necessary.

METHODS

We reviewed prospectively collected data relating to 389 occlusions of the arterial duct performed consecutively between 1994 and 2004. We inserted Cook detachable coils in 288 instances using the Amplatzer duct occluder in the remaining 101. Information was obtained regarding procedural success, displacement of the device, and re-intervention. We have followed out patients for a median of 1.15 years in those closed with the Amplatzer device, and 1.09 years in those closed with a coil.

RESULTS

In the patients in whom we used coils, occlusion was possible in 75% using venous access alone. We reintervened in 25 patients, because of embolisation of the device in 6, haemolysis in 5, and residual shunting in 14. On follow-up, complete occlusion had been achieved in 98%. We found trivial stenosis of the left pulmonary artery in 3 patients. When using the Amplatzer device, closure using venous access alone was achieved in 82%, and 2 patients required reintervention because of embolisation of the device. Complete occlusion had been achieved in all patients as judged by follow-up at 1 year, and 2 patients had trivial stenosis of the left pulmonary artery.

CONCLUSION

Arterial catheterisation is unnecessary in the great majority of patients undergoing occlusion of the arterial duct. Use of venous catheterisation alone is safe, and does not appear to increase the risk of device-related complications.

Value of computed tomographic angiography in neck and extremity pediatric vascular trauma

PURPOSE

We sought to define the sensitivity and specificity of computed tomographic angiography (CTA) in pediatric vascular injuries.

METHODS

All neck and extremity CTAs performed in pediatric patients at a level 1 trauma center were reviewed from 2001 to 2007.

RESULTS

Overall, 78 patients were identified with an average age of 15.0 +/- 4.0 (0-18 years). Males outnumbered females 3.6:1. CTA was performed for 41 penetrating and 37 blunt traumas. Most penetrating injuries were due to missile wounds (71%) or stab wounds (17%). Eleven major vascular injuries resulted from penetrating trauma. For penetrating trauma, CTA was 100% sensitive and 93% specific. CTA for penetrating trauma had a positive predictive value (PPV) of 85% and negative predictive value (NPV) of 100%. Most blunt injuries were due to motor vehicle accidents (57%), followed by pedestrian hit by car (27%). Eight major vascular injuries resulted from blunt trauma. For blunt trauma, CTA was 88% sensitive and 100% specific. CTA for blunt trauma had a PPV of 100% and an NPV of 97%. The accuracy for penetrating and blunt trauma was 95% and 97%, respectively.

CONCLUSIONS

CTA is highly sensitive, specific, and accurate for pediatric neck and extremity vascular trauma.

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).

Neonatal pulmonary sequestration: clinical experience with transumbilical arterial embolization

Pulmonary sequestration (PS) is a rare congenital malformation of the lower respiratory tract. The exact natural course of PS is not well understood and there are no well-established treatment guidelines for antenatally diagnosed PS. The aim of this study was to describe clinical outcomes in neonates with PS and to evaluate the efficacy of transumbilical arterial embolization (TUE). From 1998 to 2006, total 30 neonatal cases were included. Serial antenatal ultrasound in 26 cases found 6 (23%) regressed lesions, all of which were demonstrated on postnatal chest CT. Six (20%) cases were classified as mixed-type (combined cystic) lesions. Surgery was performed early (during initial hospitalization) in two cases and lately (after the neonatal period) in four cases. TUE was performed for 17 (57%) cases of intrapulmonary PS. Follow-up images obtained a median of 19 months (range, 4-51) after TUE demonstrated complete (9, 53%), partial (5, 29%), and no (3, 18%) regression. The regression rate was significantly higher in solid-type lesions (13/13, 100%) than in mixed-type (1/4, 25%) (P = 0.006). Complications included transient hypertension (two cases, 12%), post-embolization fever (two cases, 12%) and migration of a microcoil (one case, 6%), without long-term morbidities. Natural courses could be observed in 10 cases of extralobar PS and regression was observed in 2 cases (20%) during a median follow-up of 12 months (range, 6-45). A well-designed comparative study is warranted to evaluate the long-term efficacy and safety of TUE.

Computed tomographic angiography in pediatric blunt traumatic vascular injury

Pediatric vascular injuries are rare but can be difficult to diagnose and challenging to manage. We present our experience with computed tomographic angiography in 3 pediatric patients with vascular injuries secondary to blunt trauma. Computed tomographic angiography is noninvasive, fast, rapidly available in most centers, and can evaluate for other injuries. We present a review of the literature and recommend computed tomographic angiography as the diagnostic tool of choice in the evaluation of pediatric blunt vascular trauma.

Pediatric Cardiac-Gated CT Angiography: Assessment of Radiation Dose

OBJECTIVE

The purpose of our study was to determine a dose range for cardiac-gated CT angiography (CTA) in children.

MATERIALS AND METHODS

ECG-gated cardiac CTA simulating scanning of the heart was performed on an anthropomorphic phantom of a 5-year-old child on a 16-MDCT scanner using variable parameters (small field of view; 16 x 0.625 mm configuration; 0.5-second gantry cycle time; 0.275 pitch; 120 kVp at 110, 220, and 330 mA; and 80 kVp at 385 mA). Metal oxide semiconductor field effect transistor (MOSFET) technology measured 20 organ doses. Effective dose calculated using the dose-length product (DLP) was compared with effective dose determined from measured absorbed organ doses.

RESULTS

Highest organ doses included breast (3.5-12.6 cGy), lung (3.3-12.1 cGy), and bone marrow (1.7-7.6 cGy). The 80 kVp/385 mA examination produced lower radiation doses to all organs than the 120 kVp/220 mA examination. MOSFET effective doses (+/- SD) were as follows: 110 mA: 7.4 mSv (+/- 0.6 mSv), 220 mA: 17.2 mSv (+/- 0.3 mSv), 330 mA: 25.7 mSv (+/- 0.3 mSv), 80 kVp/385 mA: 10.6 mSv (+/- 0.2 mSv). DLP effective doses for diagnostic runs were as follows: 110 mA: 8.7 mSv, 220 mA: 19 mSv, 330 mA: 28 mSv, 80 kVp/385 mA: 12 mSv. DLP effective doses exceeded MOSFET effective doses by 9.7-17.2%.

CONCLUSION

Radiation doses for a 5-year-old during cardiac-gated CTA vary greatly depending on parameters. Organ doses can be high; the effective dose may reach 28.4 mSv. Further work, including determination of size-appropriate mA and image quality, is important before routine use of this technique in children.

Transumbilical embolization of hepatic arteriovenous malformation in a neonate with heart failure

A newborn infant presented with severe heart failure due to a large hepatic arteriovenous malformation (AVM). Umbilical artery (UA) access was safely used for immediate diagnosis and for embolization.

Vascular reconstruction using deep vein for limb length discrepancy in a child

Iatrogenic vascular injuries can result in claudication and limb length discrepancy in growing children. Traditional reconstruction has been performed with great saphenous vein as a conduit. We report the case of a 7-year-old boy with a symptomatic limb length discrepancy and vascular reconstruction using femoropopliteal vein. The use of deep vein as an autogenous conduit may facilitate reconstruction of iliofemoral arteries in preadolescent children, providing an excellent size match and an efficacious means of restoring normal blood flow.

Operative and nonoperative management of children aged 13 years or younger with arterial trauma of the extremities

BACKGROUND

Previous studies have suggested that open repair of arterial injuries in very young children often leads to less satisfactory outcomes. The aim of this study is to describe a decade's experience in the management of pediatric arterial trauma of the limbs, with an additional specific objective to evaluate the long-term outcome of arterial traumas in preschool children treated conservatively.

METHODS

Hospital charts were reviewed for all children aged < or =13 years with arterial trauma of the extremities who underwent operative or nonoperative treatment. Twenty-three children were located who had arterial traumas equally divided between the upper extremity (13) and lower extremity (10).

RESULTS

The method of treatment was either open surgical repair or medical treatment consisting of systematic heparin administration. In 11 of 12 school-aged children (>6 years; mean age, 10 years), open surgical repair was performed. In six of 11 preschool children (< or =6 years; mean, 3.2 years) medical treatment was offered. Open repair was deferred in all children <2.5 years. Autologous vein interposition grafting was the most common surgical procedure and was performed in 10 patients. There were no deaths, and 87% limb salvage (21/23) was achieved. Two patients, both in the surgical arm, underwent lower limb amputation. The long-term outcome of those treated conservatively was excellent in all but one child, in whom minor limb-length discrepancy was detected.

CONCLUSION

Surgical repair can be performed in school-aged children as in adults. Surgical treatment of arterial injuries in neonates, infants, and those children <2.5 years old might best be deferred in ischemic but nonthreatened limbs. In a nonthreatened ischemic extremity in this age group, systemic heparinization is an alternative safe method of management. Limb loss is rare if distal Doppler signals are present; but as children grow, limb shortening is a threat. In preschool children, the risks of an open surgical repair must be weighed against any potential benefits.