Central venous line-related thrombosis in children

Association of low serum albumin with venous thrombosis in pediatric patients

OBJECTIVES

The incidence of venous thromboembolism (VTE) in children is increasing, attributed in part to increased utilization of central venous catheters (CVCs). Children with protein losing disorders (PLDs) and low serum albumin may have an increased incidence of thrombosis. We sought to determine the prevalence of PLDs and hypoalbuminemia at the time of diagnosis of VTE in pediatric patients and its relationship to central venous catheters.

METHODS

We performed a single institution retrospective study of 65 consecutive hospitalized pediatric patients with an acute VTE. Data collected included clinical diagnoses, type of thrombosis, presence or absence of a CVC, and serum albumin level, if available.

RESULTS

Of 65 patients with acute VTE, 51 % (33/65) had catheter-related thrombosis (CRT), including 71 % (19/27) of patients <12 years of age and 37 % (14/38) of patients aged 12 to 23 (P = 0.008). Eleven VTEs occurred in patients with a diagnosis of a PLD; of these, ten (91 %) were CRT and one (9 %) was a non-CRT (P = 0.003). Serum albumin levels obtained within four days of diagnosis of VTE were available for 38 patients. An albumin level below the lower limit of the age-adjusted normal reference range was documented in 27/38 (71 %) patients with VTE compared to 1011/3028 (33 %) of all pediatric patients admitted to the hospital during a two-year period (P < 0.0001). Albumin levels were low in 19/22 (86 %) patients with CRT compared with 8/16 (50 %) patients with non-CRT (P = 0.019).

CONCLUSION

Low serum albumin levels are highly prevalent among pediatric patients with VTE, especially in those patients with CRT.

Secondary Anticoagulation Prophylaxis for Catheter-Related Thrombosis in Pediatric Intestinal Failure: Comparison of Short- Vs Long-Term Treatment Protocols

INTRODUCTION

Catheter-related thrombosis (CRT) is a devastating complication of central venous catheters in children with intestinal failure (IF), but the optimal preventive therapy of CRT is unknown. This study assessed the efficacy and safety of 2 protocols of secondary anticoagulation prophylaxis with low-molecular-weight heparin (LMWH).

METHODS

This is a comparative cohort study of children from 2 IF programs who received secondary anticoagulation prophylaxis with LMWH for CRT. The short-term protocol group (N = 13) received therapeutic dosing until thrombus resolution or ≤3 months. In the long-term protocol group (N = 26), prophylactic dosing continued until line removal. Patients underwent routine annual vascular ultrasound and were followed for ≥1 year. The primary outcome was development of secondary thrombosis; post hoc analysis assessed rates of secondary thrombosis at 12 months.

RESULTS

Patient demographics were similar between groups. Secondary thrombosis occurred in 8 of 13 (62%) patients in the short-term group and in 9 of 26 (35%) in the long-term protocol group (P = .019) in a median time of 144.5 and 689 days, respectively (P = .01). Secondary thrombosis within 12 months occurred in 7 of 13 (54%, short term) and 2 of 26 (8%, long term) patients (P = .001). Secondary thrombosis was associated with catheter replacements (23.5 vs 5.5 catheters per 1000 catheter days; P = .016) and longer daily parenteral nutrition (PN) infusion (24 vs 15.25 hours; P = .044). Compliance was good (>80% of doses) in 92% of patients.

CONCLUSIONS

Long-term secondary anticoagulation prophylaxis with LMWH reduces the incidence of secondary thrombosis and should be considered in children with CRT that require PN for prolonged periods of time.

Venous thromboembolism in childhood: where is Brazil after 20 years?

Due to the longer survival of critically ill children, venous thromboembolism is a problem which is becoming increasingly recognized in pediatric practice. In the last decades, several international studies have been published, shedding a light upon the epidemiology of this disease during childhood. These data show peculiarities in the clinical presentation and the significant morbidity and mortality. The new "epidemic of thrombosis" in pediatric hospitals points toward the urgent need for specific treatment and prevention protocols targeting this population. In Brazil, knowledge regarding this disease remains scarce. The lack of epidemiological data impacts both the clinical care and the design of specific public policies in the field. Thus, a national registry of pediatric venous thromboembolism is relevant to the proposal of an appropriate plan of action to create a qualified net of assistance. The improvement in educational initiatives related to the field of Pediatric Hemostasis is also very important. In this review, we have updated the epidemiological, clinical and therapeutic aspects of the disease, as well as the prevention strategies.

Effect of impregnated central venous catheters on thrombosis in paediatric intensive care: Post-hoc analyses of the CATCH trial

Purpose

The CATheter infections in CHildren (CATCH) trial reported reduced risks of bloodstream infection with antibiotic impregnated compared with heparin-bonded or standard central venous catheters (CVC) in paediatric intensive care. CVC impregnation did not increase the risk of thrombosis which was recorded in 24% of participants. This post-hoc analysis determines the effect of CVC impregnation on the risk of thrombosis leading to CVC removal or swollen limb.

Methods

We analysed patients in the CATCH trial, blind to CVC allocation, to define clinically relevant thrombosis based on the clinical sign most frequently recorded in patients where the CVC was removed because of concerns regarding thrombosis. In post-hoc, three-way comparisons of antibiotic, heparin and standard CVCs, we determined the effect of CVC type on time to clinically relevant thrombosis, using Cox proportional hazards regression.

Results

Of 1409 participants with a successful CVC insertion, the sign most frequently resulting in CVC removal was swollen limb (37.6%; 41/109), with lower rates of removal of CVC following 2 episodes of difficulty withdrawing blood or of flushing to unblock the CVC. In intention to treat analyses (n = 1485), clinically relevant thrombosis, defined by 1 or more record of swollen limb or CVC removal due to concerns about thrombosis, was recorded in 11.9% (58/486) of antibiotic CVCs, 12.1% (60/497) of heparin CVCs, and 10.2% (51/502) of standard CVCs. We found no differences in time to clinically relevant thrombosis according to type of CVC.

Conclusions

We found no evidence for an increased risk of clinically relevant thrombosis in antibiotic impregnated compared to heparin-bonded or standard CVCs in children receiving intensive care.

Paediatric venous thromboembolism: a report from the Italian Registry of Thrombosis in Children (RITI)

BACKGROUND

The Italian Registry of Thrombosis in Children (RITI) was established by a multidisciplinary team with the aims of improving knowledge about neonatal and paediatric thrombotic events in Italy and providing a preliminary source of data for the future development of specific clinical trials and diagnostic-therapeutic protocols.

MATERIALS AND METHODS

We analysed the subset of RITI data concerning paediatric systemic venous thromboembolic events that occurred between January 2007 and June 2013.

RESULTS

Eighty-five deep venous thromboses and seven pulmonary emboli were registered in the RITI. A prevalence peak was observed in children aged 10 to 18 years and, unexpectedly, in children aged 1 to 5 years. A central venous line was the main risk factor (55% of venous thromboembolic events); surgery (not cardiac) (25%), concomitant infections (23%) and malignancy (22%) were the clinical conditions most often associated with the onset of venous thromboembolism. There was a diagnostic delay of more than 24 hours in 37% of the venous thromboembolic events. Doppler ultrasound was the most widely used test for the objective diagnosis of deep venous thrombosis (87%). Antithrombotic therapy was administered in 96% of venous thromboembolic events, mainly low molecular weight heparin (60%). In 2% of cases recurrences occurred, while post-thrombotic syndrome developed in 8.5% of cases.

DISCUSSION

Although the data from the RITI are largely in agreement with published data, peaks of prevalence of thrombosis, risk factors and objective tests used for the diagnosis showed some peculiarities which may deserve attention.

Risk factors for central venous catheter-related thrombosis in children: a retrospective analysis

Central venous catheter (CVC) placement is associated with increased risk of thrombosis in the paediatric population, particularly in relation to the type of catheter and the manner of its insertion. Here, we investigate risk factors associated with CVC-related thrombosis in children, with particular emphasis on positioning of the catheter tip. Patients aged 0-18 who underwent at least one CVC placement from 2008 to 2013 at a single centre with a subsequent follow-up echocardiogram were included for a total of 104 patients and 147 lines. Data on clinical and catheter-related risk factors were collected from patient charts. Statistical analysis using Pearson's χ tests, independent samples t-test, and odds ratios were used to assess potential risk factors for thrombosis. Neither insertion site (subclavian vein or otherwise), left- vs. right-sided insertion, nor catheter type were significant risk factors for thrombosis. There were no thrombotic events reported at the superior vena cava (SVC)-right atrium junction and no significant differences in thrombotic risk with initial tip placement in the SVC-right atrium junction vs. the SVC, right atrium, or inferior vena cava. Acute lymphoblastic leukaemia was a major clinical risk factor for thrombosis. Tip movement was common and may have been an important factor in the development of CVC-related thrombi. Prospective studies can yield insight into the role of follow-up imaging in the prevention of catheter-related thrombosis in children.

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors: A prospective cohort study

BACKGROUND

Although the use of central venous catheters (CVCs) has greatly improved the quality of care of children with cancer, these catheters increase the risk of deep vein thrombosis (DVT) and the potential long-term complication of post-thrombotic syndrome (PTS). We aimed to study PTS post-CVC removal using physical, functional and health related quality of life (HRQoL) domains in childhood cancer and bone marrow transplantation (BMT) survivors.

PROCEDURE

We conducted a prospective study in a cohort of childhood cancer and BMT survivors post-CVC use. Participants were evaluated for PTS with the Modified Villalta Score (MVS) and the Manco-Johnson Instrument (MJI). HRQoL was assessed using the PedsQL™ questionnaire.

RESULTS

A total of 158 children were enrolled at a median of 41 (4-149) months from CVC removal. Signs and symptoms of PTS were present in 34% (95% confidence interval [CI] 27-43%) (MVS criteria) and 30.5% (95% CI 23.1-37.8%) (MJI criteria). Diagnosis of PTS was associated with history of CVC occlusion, history of CVC-related DVT and the use of ≥2 CVCs. The presence of signs and symptoms of PTS was a predictor for low HRQoL tested by the PedsQL™ Total Scale scores and Physical Health Summary scores.

CONCLUSIONS

PTS post-CVC removal in pediatric cancer survivors is not a rare event. The association between PTS and the history of CVC occlusion confirms earlier findings, and suggests that CVC occlusion may indicate asymptomatic DVT. PTS is also associated with lower HRQoL scores highlighting the need to study preventive measures, especially for high risk groups. Pediatr Blood Cancer 2015;62:285-290. © 2014 Wiley Periodicals, Inc.

Complications of central venous stenosis due to permanent central venous catheters in children on hemodialysis

BACKGROUND

Central venous catheters are frequently used as access for hemodialysis (HD) in children. One of the known complications is central venous stenosis. Although this complication is not rare, it is often asymptomatic and therefore unacknowledged. Superior vena cava (SVC) stenosis is obviously suspected in the presence of upper body edema, but several other signs and symptoms are often unrecognized as being part of this syndrome.

CASE-DIAGNOSIS/TREATMENT

We describe four patients with various manifestations of central venous stenosis and SVC syndrome. These sometimes life- or organ-threatening conditions include obstructive sleep apnea, unresolving stridor, increased intracranial pressure, increased intraocular pressure, right-sided pleural effusion, protein-losing enteropathy and lymphadenopathy. The temporal relationship of these complications associated with the use of central venous catheters and documentation of venous stenosis, together with their resolution after alleviation of high venous pressure, points to a causal role. We suggest pathophysiological mechanisms for the formation of each of these complications.

CONCLUSIONS

In patients with occlusion of the SVC, various unexpected clinical entities can be caused by high central venous pressure. As often the etiology is not obvious, a high index of suspicion is needed as in some cases prompt alleviation of the high pressure is mandatory.

Challenging aspects of managing hemostasis in adolescents

The prevalence of symptomatic childhood venous thromboembolism increases among adolescents. The occurrence of nonhereditary prothrombotic risk factors, e.g. oral contraceptive pills, often prescribed to adolescent females for various indications, such as tobacco use, obesity and hypertension may trigger symptomatic thrombosis, especially in carriers of genetic thrombophilia traits. On the other hand, heavy menstrual bleeding is a common clinical problem of young adolescent women. A proper diagnostic workup of these women may enable physicians to detect and treat congenital bleeding disorders, e.g. von Willebrand disease, presenting with menorrhagia. The challenges of diagnosis and treatment of either thrombosis or bleeding disorders in young adults will be discussed in this review.

Prevention and treatment of intraluminal catheter thrombosis in children hospitalised in a paediatric intensive care unit

AIM

The aim of the study was to develop and implement a protocol for the prevention and treatment of catheter related intraluminal thrombosis in a paediatric intensive care unit

METHODS

A computerised search was carried out on MEDLINE, through PubMed, using the medical subject heading 'central venous catheter', 'central venous access device', 'central venous line' associated with 'occlusion', 'obstruction', 'catheter-related thrombosis', 'critically ill patients' and 'thrombolytic therapy'. References of reviewed articles were also searched for relevant titles as well as non-randomised controlled trials and series of cases when no information of higher level of evidence was available.

RESULTS

With the information gathered, a protocol for the prevention and treatment of catheter related intraluminal thrombosis was elaborated and those recommendations that best suit our environment were included. They were agreed upon by a broad panel of professionals working in the Pediatric Intensive Care Unit and the Pharmacy Department.

CONCLUSIONS

Due to the variety of options available for the pharmacotherapeutic management of intraluminal catheter thrombosis, one measure to improve the quality of the therapy and to diminish the variability in the prescription could be the implementation of a protocol as described in this paper.

Catheter-related thrombosis: lifeline or a pain in the neck?

Central venous catheters (CVCs) are used extensively in cancer patients for the administration of therapy and phlebotomy. An important complication of CVCs is the development of catheter-related thrombosis (CRT), which becomes symptomatic in approximately 5% of the patients. Several factors, such as insertion location and position of the catheter tip, increase the risk of CRT. Prevention of CRT with systemic anticoagulant prophylaxis has largely been ineffective. In addition, the optimal diagnostic strategy and anticoagulant treatment are unclear due to the lack of well-designed studies. The most recent American College of Chest Physicians guidelines recommend (color) Doppler ultrasound more than venography as the initial diagnostic test in patients with suspected arm thrombosis. Only if the ultrasound is negative and clinical suspicion is high is further testing with D-dimer, serial ultrasound, or venography advocated. In case of CRT, removal of the catheter is not necessary if it is functional and needed for chemotherapy. Anticoagulant treatment of CRT consists of treatment with low-molecular-weight heparin (LMWH) followed by vitamin K antagonists for at least 3 months. Whether long-term treatment with LMWH is more effective than vitamin K antagonists in cancer patients with CRT is unknown, but LMWH may be advocated following the recommendations in lower limb thrombosis and cancer. In addition, the effect of new anticoagulants in CRT has not been studied.

Epidemiology and prevention of catheter-related thrombosis in patients with cancer

Central venous catheters are extensively used in patients with cancer to secure delivery of chemotherapy and facilitate phlebotomy. Unfortunately, considerable morbidity can result from early complications or late sequelae, ranging from arterial puncture, pneumothorax and bloodstream infections to catheter-related thrombosis (CRT). Contemporary studies have shown that the incidence of symptomatic CRT is ∼5%, whereas the incidence of asymptomatic CRT is higher, at 14-18%. The significance and mechanisms of catheter design, material, insertion location and technique, position of the catheter tip and other risk factors in contributing to the development of CRT are not well understood. Efforts to reduce thrombotic complications, involving flushing the catheter with heparinized solutions, the use of heparin-bonded catheters, and systemic anticoagulant prophylaxis, have been largely ineffective. More studies are needed to understand the pathophysiology of thrombotic complications, to help identify effective interventions to reduce this adverse outcome.

Characterization of central venous catheter-associated deep venous thrombosis in infants

PURPOSE

Deep venous thrombosis (DVT) is a frequent complication in infants with central venous catheters (CVCs). We performed this study to identify risk factors and risk-reduction strategies of CVC-associated DVT in infants.

METHODS

Infants younger than 1 year who had a CVC placed at our center from 2005 to 2009 were reviewed. Patients with ultrasonically diagnosed DVT were compared to those without radiographic evidence.

RESULTS

Of 333 patients, 47% (155/333) had femoral, 33% (111/333) had jugular, and 19% (64/333) had subclavian CVCs. Deep venous thromboses occurred in 18% (60/333) of patients. Sixty percent (36/60) of DVTs were in femoral veins. Femoral CVCs were associated with greater DVT rates (27%; 42/155) than jugular (11%; 12/111) or subclavian CVCs (9%; 6/64; P < .01). There was a 16% DVT rate in those with saphenofemoral Broviac CVCs vs 83% (20/24) in those with percutaneous femoral lines (P < .01). Multilumen CVCs had higher DVT rates than did single-lumen CVCs (54% vs 6%, P < .01), and mean catheter days before DVT diagnosis was shorter for percutaneous lines than Broviacs (13 ± 17 days vs 30 ± 37 days, P = .02). Patients with +DVT had longer length of stay (86 ± 88 days vs 48 ± 48 days, P < .01) and higher percentage of intensive care unit admission (82% vs 70%, P = .02).

CONCLUSIONS

Deep venous thrombosis reduction strategies in infants with CVCs include avoiding percutaneous femoral and multilumen CVCs, screening percutaneous lines, and early catheter removal.

Thrombophilia testing in neonates and infants with thrombosis

In neonates and infants with idiopathic venous thrombosis (VTE) and in pediatric populations in which thromboses were associated with medical diseases, inherited thrombophilia (IT) have been described as risk factors. Follow-up data for VTE recurrence in neonates suggest a recurrence rate between 3% in provoked and 21% in idiopathic VTE. Apart from underlying medical conditions, recently reported systematic reviews on pediatric VTE have shown significant associations between factor V G1691A, factor II G20210A, and deficiencies of protein C, protein S and antithrombin, even more pronounced when combined IT were involved. Independent from the age at first VTE onset, the pooled odds ratios (OR: single IT) for VTE ranged from 2.4 for the factor II G20210A mutation to 9.4 in neonates and infants with antithrombin deficiency. The pooled OR for persistent antiphospholipid antibodies/lupus anticoagulants was 4.9 for pediatric patients with venous VTE. The factor II G20210A mutation (OR: 2.1), and deficiencies of protein C (OR: 2.4), S (OR: 3.1) and antithrombin (OR: 3.0) also played a significant role at recurrence. Based on these data, screening and treatment algorithms must be discussed.

Diagnosis and management of central-line-associated thrombosis in newborns and infants

Although the use of central lines has many valuable applications in neonates and infants, they may cause serious mechanical, infectious and thrombotic complications. In fact, the use of central lines is the main cause for thrombosis in this age group. The frequency of central-line-related thrombosis in neonates and infants is reported to be as low as 1% when including only symptomatic cases, around 44% when systematically screened for thrombosis, and as high as 65% in autopsy studies. The risk factors for line-related thrombosis in neonates and infants include those associated with the underlying medical conditions, the duration of the line in situ, the placement of the umbilical artery catheter and the therapy used through the line. The contribution of inherited and acquired thrombophilia to central-line-related thrombosis is controversial, and the data are not sufficiently consistent to make a firm recommendation for thrombophilia screening for neonates and infants with central-line-related thrombosis. Most experts will recommend pursuing a thrombophilia work-up in the setting of a significant thrombosis event and will recommend avoiding thrombophilia work-up in subclinical and asymptomatic central-line-related thrombosis. The management of line-related thrombosis is based on expert opinion guidelines and is largely dependent on the type of the catheter and the further requirement of the catheter. Continuous heparin infusion through the central lines prevents catheter occlusion, but has no effect on occurrence of thrombosis. Currently no definitive recommendations exist for thromboprophylaxis in children, infants and neonates with central lines.

In the absence of a central venous catheter, risk of venous thromboembolism is low in critically injured children, adolescents, and young adults: evidence from the National Trauma Data Bank

OBJECTIVE

To describe the incidence and risk factors of venous thromboembolism in a large sample of critical care pediatric, adolescent, and young adult trauma patients.

DATA SOURCE

The National Trauma Data Bank-the largest and most complete aggregation of trauma registry data in the United States.

SETTING

Seven hundred eighty-four level I to level IV trauma centers.

PATIENTS

Patients ≤ 21 yrs of age who spent at least 1 day in a critical care unit during a trauma admission between 2001 and 2005.

MEASUREMENTS AND MAIN RESULTS

To characterize differences between patients with and without venous thromboembolism, we extracted variables regarding patient demographics, injury pattern and severity, procedures, total length of stay, and intensive care unit and ventilator days. Odds ratios for predictors of venous thromboembolism were estimated with a logistic regression model. Among the 135,032 critical care patients analyzed, venous thromboembolism was uncommon (6 per 1,000 discharges). Placement of a central venous catheter was a significant predictor of venous thromboembolism (odds ratio = 2.24; p < .0001) when populations were analyzed collectively. When we narrowed our focus to injuries associated with venous thromboembolism, such as lower-extremity fractures, the effects of central venous catheter were of even greater magnitude, particularly in adolescents and young adults. The risk of venous thromboembolism in critical care patients without a central venous catheter was <1% even in adolescents/young adults.

CONCLUSIONS

Venous thromboembolism is rare in young critical care trauma patients, even older adolescents. The absence of published data on both the baseline risk of venous thromboembolism in pediatric critical care patients and the efficacy and safety of venous thromboembolism prophylaxis preclude the ability to make definitive recommendations for the use of venous thromboembolism prophylaxis in this setting. Our results, however, suggest that venous thromboembolism prophylaxis may need to be considered only in critically injured adolescents and young adults with a continuing need for central venous access.

Potential of cell therapy to treat pediatric motility disorders

Gut motility disorders represent a significant challenge in clinical management with current palliative approaches failing to overcome disease and treatment-related morbidity. The recent progress with stem cells to restore missing or defective elements of the gut neuromusculature offers new hope for potential cure. Focusing on enteric neuropathies such as Hirschsprung's disease, the review discusses the progress that has been made in the sourcing of putative stem cells and the studies into their biology and therapeutic potential. It also explores the practical challenges that must be overcome before stem cell-based therapies can be applied in the clinical arena. Although many obstacles remain, the speed of advancement of the enteric stem cell field suggests that such therapies are on the horizon.

Influence of the factor II G20210A variant or the factor V G1691A mutation on symptomatic recurrent venous thromboembolism in children: an international multicenter cohort study

OBJECTIVE

To determine the relative importance of the factor (F) II G20210A or FV G1691A mutations as risk factors or predictors for fatal/non-fatal recurrent venous thromboembolism (VTE) in children.

METHODS

In the present cohort, the rate of VTE recurrence and the time to recurrence in relation to FII, FV, age, and sex was determined in consecutively enrolled patients with VTE aged newborn to

RESULTS

Of the 416 children enrolled, 44 had recurrent VTE at a median of 12 months following VTE onset. The overall incidence rate of recurrence was 19.8, 57.9 in patients with the FII variant, 17.9 for FV carriers, and 11.8 in the control cohort. When comparing FII patients, FV children and the control cohort multivariate analysis (Cox regression) adjusted for age and sex showed that the FII variant (hazard ratio 2.6; 95% confidence interval 1.1-5.9) influenced the hazard for recurrent VTE.

CONCLUSIONS

Based on multivariate analysis, the presence of the FII variant was associated with an increased risk of VTE recurrence.

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Key Words Collapse

MESH Headings

• Adolescent
• Age Factors
• Child
• Child, Preschool
• Cohort Studies
• Factor V/genetics
• Female
• Global Health
• Humans
• Infant
• Infant, Newborn
• Male
• Point Mutation
• Polymorphism, Single Nucleotide
• Prothrombin/genetics
• Recurrence
• Sex Factors
• Venous Thromboembolism/genetics

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Grants Collapse

Affiliation(s)

G Young Division of Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, CA, USA
S Becker
C Düring
F Friedrichs
N Goldenberg
G Kenet
M Manco-Johnson
C Scheffold
U Nowak-Göttl

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What is the value of magnetic resonance venography in children before renal transplantation?

Radiological evaluation before renal transplantation includes imaging of vascular anatomy, as thrombosis, narrowing and anomalies of the inferior vena cava (IVC) and/or iliac veins (IV) can influence the surgical technique. Most cases only require investigation with Doppler vessel ultrasonography (US), with magnetic resonance venography (MRV) reserved to clarify US findings and investigate high-risk patients. The purpose of this study was to compare these modalities in evaluating IVC and IV and correlate imaging and operative findings of patients at RTx surgery. Twenty-nine children, 21 (72%) of whom had subsequent RTx surgery, were investigated over 5 years with correlation of US and MRV in 62% (18 of 29). Technically difficult US examinations needing MRV for clarification occurred in six (21%), and normal US with anatomical variations on MRV was seen in three (10%). The anatomical variations consisted of left-sided IVC, aberrant right common femoral vein and a left IV partly draining into the azygos and renal veins. US is an excellent screening tool for evaluating vascular anatomy patency in children. MRV infrequently contributes beneficial information, is difficult to justify as a screening tool, and due to the risks of gadolinium in uraemia, should only be used on an individual patient basis.

Future horizons in the treatment of enteric neuropathies

Enteric neuropathies comprise a vast and disparate array of congenital and acquired disorders of the enteric nervous system (ENS), reflecting both the complexity of its neuronal composition and the many interactions that modulate its function. Although present therapeutic strategies, largely limited to surgery and the provision of artificial nutrition, have transformed the early survival and life of sufferers, levels of morbidity and mortality remain unacceptably high. This highlights the need to develop new treatments for enteric neuropathies. In the last decade, the tremendous advances in molecular biology and genetics have significantly enhanced our understanding of ENS development and function. Coupled with equivalent progress in the fields of pharmacology and stem-cell biology, this has led to the identification of novel tools and targets for therapy, which either aim to optimise the function of the intrinsic ENS or replace/replenish components of an inadequate or dysfunctional ENS. This article reviews current work on a number of these interventions with a particular focus on the use of ENS stem cells as potential therapeutic tools for enteric neuropathies.

Radiologically Placed Tunneled Internal Jugular Catheters in the Management of Chronic Hemodialysis and Long-term Infusion Therapies in the Pediatric Population

PURPOSE

To evaluate the long-term outcomes of radiologically inserted dual-lumen hemodialysis and infusion catheters in pediatric patients.

MATERIALS AND METHODS

The authors retrospectively reviewed the outcomes of 114 tunneled internal jugular catheters in 71 consecutive pediatric patients between March 2003 and May 2006. Forty hemodialysis catheters were placed in 23 patients (11 girls, 12 boys), and 74 infusion catheters were placed in 48 patients (14 girls, 34 boys). The mean patient age was 11.2 years (range, 1-16 years) in the hemodialysis group and 7.86 years (range, 4 months to 16 years) in the infusion group.

RESULTS

The technical success rate was 100%. The mean duration of catheter use was 84 days (range, 5-730 days) in the hemodialysis group and 58 days (range, 3-206 days) in the infusion group. Nine hemodialysis (22%) and 29 infusion (39%) catheters were electively removed. The most common reasons for catheter removal were malfunction (22%) in the hemodialysis group and completion of therapy (39%) in the infusion group. Revisions were performed at a rate of 0.6 and 0.4 per 100 catheters days in the hemodialysis and infusion groups, respectively. Total infection rates were 0.15 and 0.38 episodes per 100 catheter days in hemodialysis and infusion catheters, respectively. Mean primary device service intervals were 86 and 60 days for hemodialysis and infusion catheters, respectively, with total access site service intervals of 140 and 71 days.

CONCLUSION

Radiologically placed tunneled internal jugular catheters appear to be safe and effective, with very low complication rates for both hemodialysis and long-term infusion therapies. Higher infection rates were seen in patients with cancer.

Ultrasound-guided subclavian vein cannulation in infants and children: a novel approach

BACKGROUND

Central venous cannulation in infants remains challenging even for experienced paediatric anaesthesiologists. Ultrasound (US)-guidance techniques are proven to be safer for internal jugular vein catheterization. But the subclavian vein (SCV) is often the preferred site for long-term central venous catheterization in children. We describe a novel US-guided approach for SCV cannulation in infants and children.

METHODS

The principle of this technique is to place the US probe at the supraclavicular level to obtain a longitudinal view of the SCV, and to gain access to the vein via the usual infraclavicular route to cannulate it under ultrasonic control. Details and pitfalls of this technique are described. The prospectively collected results of our first 25 punctures are reported.

RESULTS

Patients' weight and age range were 2.2-27 kg and 1 day to 9 yr, respectively: 76% of the children weighed less than 10 kg. The success rate at the first attempt was 84% and 100% after two attempts. An asymptomatic thrombus in the SCV could also be detected with this technique.

CONCLUSIONS

This US-guided approach of the SCV offers a new possibility for central venous catheterization in children. This technique seems promising for children less than 10 kg and probably also for older children. It provides good quality needle guidance and allows to check the vessel patency before puncture.