Central line-associated venous late effects in children without prior history of thrombosis

Background: The frequency of asymptomatic central line-associated thromboses is high and well recognized among children with cancer, while the long-term consequences are mainly unknown. Aim: In a cross-sectional study, we evaluated clinical and radiological venous outcome in children with previous long-standing intravascular catheters. Methods: The study enrolled 71 children previously treated for malignant or haematological diseases, 4-180 (median 37) mo after removal of their central lines. Inclusion criteria were a prior central line in a jugular vein for a minimum of 6 mo and no previous history of thrombosis. The children had clinical examination for post-thrombotic syndrome (PTS) and Doppler ultrasonography of the central neck veins. Twelve children had additional venous magnetic resonance imaging (MRI). But no kind of venography was performed in the remaining. Results: We observed mild PTS with increased superficial collaterals in four children (6%), but no cases of more severe PTS. None complained of symptoms related to venous late effects. By ultrasonography, post-thrombotic venous alterations were detected in 17 children (24%), and five of these had complete occlusion of the veins. The sensitivity for pathologically increased collaterals to identify occlusive thrombosis was 0.6, while the specificity was 0.98. Occlusive venous thromboembolism was associated with the total number of central venous lines (CVLs; p=0.002), previous severe CVL-associated infections (p=0.001) and duration of central line in place (p=0.042).

Conclusion: In spite of no prior history of thrombosis, children with previous long-term jugular lines frequently had local thrombotic sequelae, while clinical symptoms of PTS were rare.     

Bacterial aetiology of acute osteoarticular infections in children

Aim: To study the bacterial aetiology of acute osteoarticular infections in children and to analyse the efficiency of culture methods. Methods: Bacteriological data of 407 cases of clinically suspected osteoarticular infections affecting 406 children hospitalized in an orthopaedic surgery department between 1999 and 2002 were retrospectively reviewed. Results: Bacterial cultures from clinical specimens were positive in 74 cases (18%): 38 cases of septic arthritis and 36 cases of bone infections (osteitis, osteomyelitis or osteoarthritis). The use of liquid medium bottles to grow bacteria from articular fluids increased the rate of positive cultures compared to the use of standard solid media (p=0.0001). The most commonly recovered pathogen was Staphylococcus aureus (44%) followed by Kingella kingae (14%), Streptococcus pyogenes (10%) and Streptococcus pneumoniae (10%). K. kingae was most frequently isolated among children under 36 mo of age (p=0.0003), whereas S. aureus was most frequently isolated among children over 36 mo (p=0.0015).

Conclusion: By improving our culture method, we observed a recrudescence of isolation of K. kingae, but S. aureus remains the main pathogen isolated from osteoarticular infections in children. This finding is useful for the adaptation of a probabilistic antibiotic treatment of these infections.     

Venous thromboembolism

Incidence of venous thromboembolism (VTE) in children is rapidly rising. Frequent use of central venous lines (CVLs) in children with a variety of disease processes has contributed to increased incidence of VTE. In addition, increased detection of VTE has been possible due to the availability of sensitive imaging studies such as Color Duplex/Doppler ultrasound, lineogram and venogram. Heightened awareness of congenital prethrombotic disorders may help identify children at higher risk of thrombosis. Anticoagulation with heparin, low molecular weight heparin (LMWH) and oral anticoagulant such as warfarin are used for the treatment of VTE. Thrombolytic therapy may be indicated in some cases. Clinical presentation, management and pathogenesis including role of congenital prethrombotic disorders in pediatric VTE are discussed.     

Thromboprophylaxis of central venous lines in children with cancer: the first steps taken on the long road ahead

Approximately one third of children with malignancy and central venous lines develop catheter-related thrombosis, with the reported sequelae including death, pulmonary embolism, chylothoraces, superior vena cava syndrome and post-thrombotic syndrome. These complications prompt the design and completion of randomized, controlled trials to determine a safe and efficacious therapy to prevent these thromboses. The authors Ruud et al. have presented a well-designed, randomized, controlled trial which demonstrates the lack of utility of using low-dose warfarin to prevent catheter-related thrombosis in children with central lines and acute lymphoblastic leukaemia. The difficulties with warfarin in children are again demonstrated in this study.

Conclusion: Further studies are warranted using other thromboprophylactic agents with less or no monitoring and fewer drug interactions, including the newer anticoagulant agents such as direct thrombin inhibitors.     

Early post-convulsive prolongation of QT time in children

Aim: An important differential diagnosis of seizures in childhood is the long QT syndrome. Childhood epilepsy occurs about 400 times more often than long QT syndrome. We had observed children with slight post-convulsive prolongation of QT time more often than the reported incidence of long QT syndrome. We therefore conducted a prospective study to define the characteristics of post-convulsive prolongation of QT time in children. Methods: We investigated 30 consecutive infants and children (3 mo to 14 y) within 2 h after seizures. A follow-up ECG was obtained 1-9 d later. We also obtained ECGs from 30 healthy age- and gender-matched controls. We calculated the QT interval corrected for heart rate (QTc) by Bazett's formula in leads II, V5, V6, QT dispersion and the number of notched T waves. Results: We found a QTc interval of more than 440 ms in one or more leads in the first ECG in seven of 30 infants and children compared to 1 of 30 in the follow-up ECG (p=0.0003) and two of 30 in the healthy controls (p=0.14). Average QTc was higher for all leads in the first ECG. This was statistically significant in leads II (414 vs 402 ms, p=0.008), V5 (416 vs 404 ms, p=0.002) and V6 (415 vs 399 ms, p=0.001). Compared to healthy controls, QT dispersion was slightly larger in the early post-convulsive ECG (36 vs 31 ms, p=0.03). Notched T waves occurred more frequently in the early compared to the late post-convulsive ECGs (p=0.009).

Conclusion: Slight to moderate post-convulsive prolongation of the QT interval is not rare but transient in paediatric patients.     

The effect of nebulized budesonide treatment in children with mild to moderate exacerbations of asthma

Background: The role of inhaled corticosteroids in the treatment of acute asthma remains a controversial subject. Objective and methods: A randomized, double-blind, placebo-controlled parallel-group clinical trial on the effect of a 5-d course of nebulized budesonide treatment in children with mild to moderate exacerbation of asthma was performed. The need for systemic corticosteroid intervention was evaluated as the primary outcome measure. Results: Sixty-seven children aged 6 to 15 y were enrolled. During the emergency department phase, they received three nebulizations of either budesonide(1 mg/dose) or placebo, and then in the home phase of the study, they continued their study medications twice a day for another 4 d. Though the level of improvement in the emergency department phase was similar between the groups given either budesonide or placebo treatments (6.8±1.9% vs 4.0±1.5%, p=0.30, respectively), nebulized budesonide caused a trend towards a benefit in terms of the need for systemic corticosteroid intervention (2/33 vs 7/34, p=0.07), but not in secondary outcome measures.

Conclusion: Though we show a tendency towards a benefit with nebulized budesonide in children with mild to moderate exacerbations in terms of prevention of progression of the illness, the documented benefit is small and includes, at least, consideration for clinical significance, cost-effectiveness, impracticality and safety.     

Using radioligand-binding assays to measure tissue transglutaminase autoantibodies in young children

Aim: To measure autoantibodies against tissue transglutaminase (tTG) in young children prospectively screened for coeliac disease (CD). Methods: In total, 652 children aged 2.9 (2.5-4.2) y were analysed for IgA-tTG and IgG-tTG with radioligand-binding assays and IgA endomysial antibodies (EMA) by indirect immunofluorescence. Antibody-positive children were retested after 1.2 (range 0.2-1.9) y. Intestinal biopsy was performed on children with persistently high antibody levels. Results: In total, 3.2% (95% CI: 1.9-4.6%) of the 652 children were positive for at least one antibody at baseline: 2.5% (95% CI: 1.3-3.7%) for IgA-tTG, 1.7% (95% CI: 0.7-2.7%) for IgG-tTG and 2.9% (95% CI: 1.6-4.2%) for IgA-EMA, respectively. Ten children were positive for all three antibodies, five for both IgA-tTG and EMA, four for EMA only, one for IgA-tTG and another for IgG-tTG. IgA-EMA titres correlated with IgA-tTG levels (r = 0.73, p = 0.0003). At follow-up, seven of 20 children remained positive for all three antibodies, three for IgA-tTG only, one for both IgA-tTG and EMA, one for IgA-tTG and IgG-tTG, and the remaining child refused further participation. Three biopsies showed villous atrophy, two increased intraepithelial lymphocytes and two normal findings. Biopsy was not performed in four children with low or declining tTG antibody levels at follow-up and in one child who declined. CD was evident in 0.5% (95% CI: 0.0-1.0%) (3/652).

Conclusion: This study revealed a high number of young children positive for tTG antibodies as well as EMA, but the majority showed declining levels in both antibodies over time. We suggest using radioligand-binding assays for quantitative measurement of tTG antibodies when change in antibody levels is studied in young children.     

Cerebral excitatory amino acids and Na+, K+-ATPase activity during resuscitation of severely hypoxic newborn piglets

We tested the hypothesis that early brain recovery in hypoxic newborn piglets is improved by resuscitating with an O₂ supply close to the minimum level required by the newborn piglet brain. Severely hypoxic 2-5-d-old anaesthetized piglets were randomly divided into three resuscitation groups: hypoxaemic (n = 8), 21% O₂ (n = 8), and 100% O₂ groups (n = 8). The hypoxaemic group was mechanically ventilated with 12-18% O₂ adjusted to achieve a cerebral venous O₂ saturation of 17-23% (baseline; 45±1%, mean±SEM). During the 2h resuscitation period, extracellular aspartate and glutamate concentrations in the cerebral striatum were higher during hypoxaemic resuscitation (p = 0.044 and p = 0.055, respectively) than during resuscitation with 21% O₂ or 100% O₂, suggesting an unfavourable accumulation of potent excitotoxins during hypoxaemic resuscitation. The cell membrane Na⁺,K⁺-ATPase activity of cerebral cortical tissue after 2 h resuscitation was similar in the three groups (p = 0.30). In conclusion, hypoxaemic resuscitation did not normalize early cerebral metabolic recovery as efficiently as resuscitation with 21% O2 or 100% O₂. Resuscitation with 21% O₂ was as efficient as resuscitation with 100% O₂ in this newborn piglet hypoxia model.     

Behavioural effects of phenylalanine-free amino acid tablet supplementation in intellectually disabled adults with untreated phenylketonuria

Aim: To evaluate the effects of phenylalanine (Phe)-free essential amino acid (AA) tablets enriched in tyrosine and tryptophan on the performance of intellectually disabled adult patients with untreated phenylketonuria (PKU). Methods: Phe-free AA tablets and placebo tablets were administered to 19 untreated PKU subjects on a normal diet for 6 mo in a prospective double-blinded crossover study. The adaptive behaviour of the patients was tested prior to the study and at 6 and 12 mo after the start, using a simplified version of the Vineland Adaptive Behaviour Scale. For each sub-domain, the patients were rated either “0” (for poor performance) or “1” (for good performance). Neurological signs and symptoms and specific behavioural characteristics were recorded monthly by caretakers. Every 6 mo, neurological examination of the patients was performed, and the caretakers were interviewed. The statistical significance of the results was tested by means of the Fisher's exact and Wilcoxon tests. Results: The most significant changes were an improved concentration and the development of a meaningful smile, which were observed in 44% and 43% of the patients on AA tablet treatment, respectively, but not patients on placebo. Other important but less significant changes included increased awareness of external stimuli (63%) and less self-injury (43%), and 40% were smiling and laughing occasionally. The mean overall rating increased from an initial value of 6.3 to 10.1 in patients when on AA tablet treatment (p=0.002), and to 7.0 in patients when on placebo (p=0.068). The difference between active AA treatment and placebo was statistically significant (p=0.027).

Conclusions: This pilot study suggests that Phe-free AA tablets enriched in tyrosine and tryptophan may improve the quality of life in some intellectually disabled adults with untreated PKU.     

Interaction of Antibiotics and Warfarin in Pediatric Cardiology Patients

Antibiotics are known to alter the anticoagulation induced by warfarin in adults, but little is known about this interaction in children. In a retrospective review of patients under the age of 21 years, we found that antibiotic therapy (89 courses of antibiotics in 23 patients) was associated with an increase in the mean international normalized ratio (INR) from 2.7 to 3.6. The change in INR correlated inversely with patient age. These data suggest that more intensive monitoring of the INR after starting antibiotics may help to mitigate excessive anticoagulation in children receiving warfarin.     

Somatic factors at 8 years of age in children with recurrent use of antibiotics in early infancy

Aim: To examine the influence of recurrent therapy with antibiotics (RTA) in infancy on children's somatic factors at 8 y of age. Methods: Subject selection was based on stratified randomized cluster sampling. Altogether 1287 infants were potential participants in the follow-up study. Children with ≥6 courses of antibiotics (100 children) during their first 18 mo of life and children with no (62%) or ≤2 courses (38%) of antibiotics participated in a clinical examination in a case-control setting (100 matched controls) at the age of 8 y. Results: The children with RTA continued to have more infections and had had more courses of antibiotics compared to controls during the follow-up. There was no clinically significant difference in the somatic and dental status at the age of 8 between the two groups. The parents of the children with RTA reported significantly more often recurrent infections than the parents of the controls.

Conclusions: The children with recurrent therapy with antibiotics in early childhood also continue to be prescribed more antibiotics in later childhood when compared to those who received no or few antibiotics in infancy. However, recurrent infections and medications do not seem to have a marked effect on the somatic and dental status of these children at 8 y of age.     

Complications of central venous catheterization in critically ill children

BACKGROUND: Placement of central venous catheter is essential in the management of critically ill children. The purpose of the present paper was to evaluate the success rate, mechanical and thrombotic complications and risk factors associated with these complications from different central venous access sites in critically ill children. METHODS: A prospective study was undertaken from February 2000 to March 2005 of 369 central venous catheterizations in children in a pediatric intensive care unit. RESULTS: The veins most frequently used were femoral vein (45%), subclavian vein (32.2%), and internal jugular vein (22.8%). Mean +/- SD duration of catheterization was 9.5 +/- 6.5 days. The procedure was performed under emergency conditions in 18% of patients with an overall success rate of 92.4%. The success rate was significantly lower in younger patients with subclavian catheterization. Insertion-related complications were noted, including 33 arterial punctures (8.9%), 27 cases of malposition (7.3%), 19 hematomas (5.2%), 12 cases of minor bleeding (3.3%), and three cases of pneumothorax (0.8%), and they were more common in the subclavian vein than in the internal jugular and femoral vein. Multiple attempts and failed attempts significantly correlated with higher incidence of complications. Maintenance-related complications included obstruction (n = 26; 7%), accidental removal (n = 14; 3.8%), central venous thrombosis (n = 8; 2.2%), subcutaneous extravasation (n = 14; 3.8%), dislodgment (n = 1; 0.25%), and extravascular infusion (n = 1; 0.25%). The frequency of catheter maintenance-related complications was significantly higher in femoral catheterizations and increased significantly with an increase in the duration of catheterization. A total of five serious complications were seen (pneumothorax in three, dislodgment in one and extravascular infusion in one) in the present series. CONCLUSIONS: Central venous catheterization in critically ill children is a relatively safe procedure, with a 1.3% rate of serious complications and no mortality. It seems safer to choose initially the femoral or internal jugular vein instead of the subclavian vein because of high success rate without serious insertion-related complications.     

Morbidity in children born to women infected with human immunodeficiency virus in South Africa: does mode of feeding matter?

Aim: To examine infant morbidity risks associated with refraining from breastfeeding where it is used in an attempt to prevent mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV). Methods: The population consisted of infants born to HIV-infected women in South Africa who were participating in a vitamin A intervention trial to prevent MTCT of HIV. Women chose to breastfeed or formula feed their infants according to UNAIDS guidelines. Actual feeding practices and morbidity were recorded at clinic follow-up visits at 1 wk, 6 wk, 3 mo and every 3 mo thereafter until 15 mo of age or cessation of breastfeeding. The infant's HIV status was assessed according to a predetermined algorithm. Results: HIV-infected infants who were never breastfed had a poorer outcome than those who were breastfed; 9 (60%) of those who were never breastfed had 3 or more morbidity episodes compared with 15 (32%) of breastfed children [odds ratio (OR) 4.05, 95% confidence interval (95% CI) 0.91-20.63, p = 0.05]. During the first 2 mo of life, never-breastfed infants (regardless of HIV status) were nearly twice as likely to have had an illness episode than breastfed infants (OR 1.91, 95% CI 1.17-3.13, p = 0.006).

Conclusion: The significant extra morbidity experienced in the first few months by all never-breastfed infants and at all times by HIV-infected infants who are not breastfed needs to be considered in all decisions by mothers, health workers and policy makers so as not to offset any gains achieved by decreasing HIV transmission through avoiding breastfeeding.     

肿瘤患儿血管通道装置的选择和应用

为开展化疗泵在儿童肿瘤病例的临床应用。对18例恶性肿瘤患儿分别经颈外静脉和颈内静脉置管经皮下隧道于侧胸壁皮下埋置化疗泵。目前18例中1例已化疗结束,17例仍在经泵化疗中,18例患儿总计带泵2241天,经泵化疗375天。术后无气胸、无气栓形成及局部出血,无术后血流感染,无血栓形成及管腔闭塞,提示在诸多血管通道装置中,化疗泵对于儿童病例更为适合。颈外静脉切开置管在婴幼儿病例是一种安全可靠的途径。全麻下操作,颈外静脉切开插管,术后管理和操作的规范化是预防和减少术后并发症的重要因素。     

婴幼儿肺静脉异位引流术后肺静脉狭窄的再干预治疗

目的分析婴幼儿肺静脉异位引流术后肺静脉狭窄(pulmonary vein stenosis,PVS)的原因,总结再干预治疗的经验。方法回顾性分析2012年5月至2019年12月郑州大学附属儿童医院胸心外科收治的13例肺静脉异位引流术后PVS患儿的临床资料。其中,男8例,女5例;年龄为(7.2±4.6)个月,范围在6~31个月;体重为(6.9±3.4)kg,范围在5.0~17.6 kg;完全性肺静脉异位引流(total anomalous pulmonary venous connection,TAPVC)术后12例,部分性肺静脉异位引流(partial anomalous pulmonary venous connection,PAPVC)术后1例。13例患儿再干预治疗前均给予心脏超声及心脏CT血管造影检查。其中,吻合口处狭窄7例,单支肺静脉狭窄4例(肺静脉于左房开口处狭窄2例,肺静脉远端狭窄1例,肺静脉近端狭窄1例),双支肺静脉狭窄(均为左侧)2例。9例采用Sutureless技术,3例采用牛心包补片扩大,1例球囊扩张后效果差后行牛心包补片扩大。结果13例患儿均顺利完成手术,住院期间死亡2例。其中,1例经体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)辅助治疗3 d后因颅内出血死亡;1例因原有脑部疾病,家属拒绝使用ECMO辅助治疗,后放弃治疗。另11例患儿随访3~36个月,无延迟死亡。1例采用的Sutureless技术和1例采用中心包补片扩大患儿术后随访3年,肺静脉流速为1.6~1.9 m/s,现随访观察中。结论儿童PVS多见于肺静脉畸形术后,尤其是TAPVC术后,应早期再干预治疗。Sutureless技术能明显改善PVS的预后。     

超声引导下不同部位中心静脉置管在婴幼儿休克中的应用及临床分析北大核心CSCD

目的分析超声引导下不同部位中心静脉置管在婴幼儿休克中应用的临床特点,探讨在婴幼儿休克中应如何快速选择中心静脉置管部位。方法回顾性收集2016年1月至2020年12月广东医科大学附属东莞儿童医院儿童重症监护室收治的112例诊断为休克并进行中心静脉置管的婴幼儿临床资料,根据是否在超声引导下进行置管分为超声组(70例)及体表定位组(42例),总结分析患儿在超声引导下不同部位置管的应用情况,对各部位置管的一针成功率、总成功率、置管时间及并发症进行比较。结果与体表定位组相比,超声组颈内静脉及股静脉置管的一针成功率增高,置管时间缩短,并发症发生率减少(P<0.05)。超声组中,行颈内静脉置管比例最高(51%,36/70),其次为股静脉(33%,23/70),锁骨下静脉最少(16%,11/70)。超声引导下不同置管部位比较,颈内静脉成功置管时间最短[5.5(5.0,6.5)min](P<0.05);不同置管部位的并发症发生率比较差异无统计学意义(P>0.05)。结论在婴幼儿休克状态下,应用超声引导下行颈内静脉置管可作为临床医生优先选择的置管方式。     

Risk factors for venous thrombosis in Swedish children and adolescents

Aim: To identify prothrombotic risk profiles in children and adolescents referred to a regional coagulation centre in southern Sweden for a first thrombotic event. Methods: One hundred and twenty-eight consecutive children and adolescents (newborn to 20 y) referred for evaluations of a first episode of venous thrombosis were investigated. Clinical data were collected retrospectively, and the following variables were investigated: protein C, protein S, antithrombin; resistance to activated protein C; the genotypes FV-G1691A, F II-G20210A, MTHFR-C677T, MTHFR- A1298C; coagulation factors VIII and XI. Results: 104/128 subjects (81%) had identifiable acquired risk factors, most often indwelling catheters and hormone therapy. Predisposing genetic factors related to thromboembolic events were revealed in 53/83 (64%) of subjects who agreed to follow-up blood sampling, and 17/83 (20%) had two or more inherited risk factors. Combinations of genetic and acquired risk factors were identified in 45/83 (54%) of the subjects, and 77/83 (93%) had at least one such risk factor. Both sexes had one peak in frequency at less than 1 y of age and then an increase during adolescence, more in females than in males. Plasma values for coagulation factors VIII and XI were age appropriate and showed a normal Gaussian distribution.

Conclusion: This study identified prothrombotic risk profiles in almost all children and adolescents with venous thrombosis, which underlines the importance of careful evaluation of genetic and acquired risk factors.     

Totally implantable central venous access devices in children with hemato-oncologic malignancies: evaluation of complications and comparison of incidence of febrile episodes with similar patients without central venous access devices

The incidence of mechanical and infectious complications of totally implantable central venous access devices (TIDs) must be related to underlying disease, intensity of the chemotherapy, and frequency of manipulations. Records of the patients hospitalized from January 2002 to May 2005 were evaluated. Patients with TIDs were matched with patients without TIDs having the same malignancy and the same anti-neoplastic chemotherapy. Catheter-related complications were documented and corresponding phases of the chemotherapy in matched pairs were compared with regard to infections. TIDs were inserted in 31 patients with a median age of 4.3 years (22 acute leukemia, 1 NHL, and 8 solid tumors). Total number of catheter days was 5268, with a median catheter life of 174 days (range 9-493 days). Nine catheters (29%) were removed due to mechanical and infectious complications. There was 13 catheter-related infections with a rate of 2.46/1000 catheter days. Total number of mechanical complications was 5 and overall rate of complications was 3.41/1000 catheter days. The rate of febrile episodes was 54 and 41 in the TID and no TID group, respectively (p: .11). Duration of neutropenia was 9.6 and 7.4 days and duration of fever per febrile attack was 5.6 and 4.4 days in the TID and no TID group, respectively (p: .047 and .56). Although most of the patients in this study had hematological malignancy and required frequent manipulation, the results were similar to those in developed countries. TIDs are essential for management of chemotherapy in pediatric malignancies with acceptable complications.     

Impact of Obesity on the Risk of Venous Thromboembolism in an Inpatient Pediatric Population

Introduction: The incidence of venous thromboembolism in children has increased significantly over the past 20 years. Over the same period of time, there was an increase in the prevalence of obesity in the pediatric population. Obesity is a known risk factor for VTE in adults, but little information is available in children. Methods: This study evaluates the relation between obesity and VTE using a retrospective, case–control design, comparing the body mass index (BMI) of patients admitted with a diagnosis of VTE versus patients admitted with other diagnoses, at a single institution, between 2007 and 2011. Results: We studied 48 inpatients diagnosed with deep venous thrombosis or pulmonary embolism and a control group of 274 age and gender matched patients admitted with other diagnoses. We found obese patients (BMI > 95th percentile) to have significantly higher risk of VTE (odds ratio 2.1, with 95% CI 1.1–4.2) than patients of normal weight (BMI < 85th percentile). Overweight patients (BMI 85th–95th percentile) did not demonstrate a significant change in risk. Most of the VTE patients were adolescents and the majority of them had other identifiable risk factors for thrombosis. Conclusion: This study establishes a correlation between obesity and VTE in a group of hospitalized children, showing a risk for VTE in obese children similar to the one described in much larger adult cohorts.     

Central venous line thrombosis in children and young adults with thalassemia major

High doses of intravenous deferoxamine via central venous line (CVL) has recently been shown to improve survival in patients with noncompliant thalassemia major (TM). The aim of this retrospective study was to evaluate the extent of CVL-related thrombosis and to determine the presence of prothrombotic factors in children and young patients with TM on such a regimen. Twenty-three patients (median age 13, range 5-25 years) with TM in whom a tunneled CVL was inserted for intensification of iron chelation were evaluated for signs and symptoms of thrombosis and for inherited and acquired risk factors of thrombosis. Mean duration of CVL placement was 37 ± 31 months (range 6-98 months). Eight patients (35%) had CVL-related thrombosis diagnosed clinically or by echocardiography. Nine patients (39%) had prothrombotic factors, but the thrombosis subgroup did not differ from the other group in age, platelet counts, duration of CVL placement, or the presence of predisposing prothrombotic factors. Based on the high rate of CVL-related thrombosis, routine monitoring is suggested for CVL thrombosis in this population.