Central venous access devices in children with congenital coagulation disorders: complications and long-term outcome

Factors affecting mechanical complications of central venous access devices in children

PURPOSE

Factors leading to mechanical complications following insertion of central venous access devices (CVADs) in children are poorly understood. We aimed to quantify the rates and elucidate the mechanisms of these complications.

METHODS

Retrospective (2016-2021) review of children (< 18 years old) receiving a CVAD. Data, reported as number of cases (%) and median (IQR), were analysed by Fisher's exact test, chi-squared test and logistic regression analysis.

RESULTS

In total, 317 CVADs (245 children) were inserted. Median age was 5.0 (8.9) years, with 116 (47%) females. There were 226 (71%) implantable port devices and 91 (29%) Hickman lines. Overall, 54 (17%) lines had a mechanical complication after 0.4 (0.83) years from insertion: fracture 19 (6%), CVAD migration 14 (4.4%), occlusion 14 (4.4%), port displacement 6 (1.9%), and skin tethering to port device 1 (0.3%). Younger age and lower weight were associated with higher risk of complications (p < 0.0001). Hickman lines had a higher incidence of complications compared to implantable port devices [24/91 (26.3%) vs 30/226 (13.3%); p = 0.008].

CONCLUSION

Mechanical complications occur in 17% of CVADs at a median of < 6 months after insertion. Risk factors include younger age and lower weight. Implantable port devices have a lower complications rate.

LEVEL OF EVIDENCE

Level 4: case-series with no comparison group.

Pediatric central venous catheterization: The Role of the Aortic Valve in Defining the Superior Vena Cava-Right Atrium Junction

The aortic valve (AV) has been used as a surrogate marker for the superior vena cava-right atrium (SVC-RA) junction during the placement of central venous catheters. There is a paucity of evidence to determine whether this is a consistent finding in children. Eighty-seven computed tomography scans of the thorax acquired at local children's hospitals from April 2010 to September 2011 were retrospectively collected. The distance between the SVC-RA junction and the AV was measured by dual consensus. The cranio-caudal level of the junction and the AV were referenced to the costal cartilages (CCs) and anterior intercostal spaces (ICSs). The results confirmed that the SVC-RA junction has a variable relationship to the AV. The junction was on average 3.1 mm superior to the AV. This distance increased with age. In the <1-year-old age group, the junction was on average 1.3 mm superior to the AV (range: -6 to 11 mm). In the 1-2 years old age group: 3.5 mm (range: -8 to 15 mm). In the 3-6 years old: 3.8 mm (range: -9 to 13 mm). In the >7 years old age group: 4 mm (range: -11 to 16 mm). The surface anatomy of the SVC-RA junction was variable, ranging from the second ICS to sixth CC. The SVC-RA junction has a predictable relationship to the AV, and this can be used as an adjunct marker for accurate placement of central venous catheters except in the smallest neonates. Clin. Anat. 32:778-782, 2019. © 2019 Wiley Periodicals, Inc.

Arteriovenous shunts as venous access in children with haemophilia

INTRODUCTION

Venous access is essential in patients with haemophilia for administration of factor concentrates. Peripheral venipuncture may be challenging, particularly in young children or during immune tolerance induction (ITI). Central venous access devices (CVADs) carry a significant risk for complications. An alternative for venous access is peripheral arteriovenous shunts (AVSs), but there is sparse documentation in the literature. The aim of this study was to document our experience with AVS over 12 years in 27 boys with severe haemophilia.

METHODS

For AVS creation, a subcutaneous vein is connected end-to-side with an artery at the wrist (Cimino) or at the forearm (Gracz shunt). Factor concentrates were substituted as for intermediate size surgery. To prevent shunt occlusion, heparin (5 units/kg/h) was given during the first 3 days.

RESULTS

Indications for AVS creation were prophylaxis start (n = 20) and ITI (n = 7). Age at shunt insertion was median 1.5 years (minimum 8 months; maximum 11.7 years). Shunt maturation was achieved within a median of 3 weeks after surgery (1.5 weeks; 18 weeks). Age when home treatment was established was median 2.1 years (9 months; 11.7 years). Four patients required AVS revisions due to stenosis, but 26 of 27 patients (96%) achieved good long-term shunt function. There were few other complications.

CONCLUSION

Arteriovenous shunts provide a good alternative to CVAD and carry a lower risk of complications. AVSs allow earlier start of prophylaxis and home therapy with an improved quality of life for patients and families.

Dislocation of central venous catheters in pediatric patients

Children have limited venous access possibilities; therefore, when long-term therapy is necessary, it is better to place a catheter in a central vein. The Port catheter, totally implanted, is less exposed to the risk of infection and permits a normal life. However, there is the possibility of the displacement or fragmentation of the catheter that can be diagnosed initially only by clinical symptoms and later by a chest X-ray. We report a case of disconnection between the Port catheter and the reservoir resulting in catheter migration to the left pulmonary artery.

Implantable central venous access device in infants: Long-term results

BACKGROUND

The management of central venous access device (CVAD) is extremely difficult in babies and small infants (BSI). We therefore compared the long-term results and complications of CVAD in BSI with those in children.

METHODS

One hundred and twenty patients were divided into two groups as follows: age <1 year or weight <10 kg (group A; 25 patients); and age ≧1 year and weight ≧10 kg (group B; 95 patients). The clinical results were retrospectively compared between the groups.

RESULTS

Mean age and weight were 12.5 ± 5.9 months and 8.2 ± 1.2 kg in group A, and 78.8 ± 58.9 months and 20.9 ± 13.6 kg in group B. Operation time was 57 ± 29 min in group A and 52 ± 21 min in group B (P = 0.38). The catheter was advanced with difficulty into the central vein in five and in 16 patients (P = 0.77), and surgical complications occurred in one and in seven patients in groups A and B, respectively (P > 0.99). The CVAD remained in place for 627 ± 494 and 550 ± 414 days (P = 0.47) and was removed before treatment completion in five and in 14 patients in groups A and B, respectively (P = 0.54).

CONCLUSION

The clinical results for CVAD in BSI did not differ from those in children. CVAD are useful and safe for the treatment of BSI with serious diseases.

The incidence of catheter-associated venous thrombosis in noncritically ill children

OBJECTIVE

Previous studies estimated the incidence of catheter-associated venous thrombosis to be between 2% and 81%. Our goals were to define the incidence rate of catheter-related thrombosis in a hospitalized, noncritically ill, pediatric population and to determine modifiable factors that alter the risk of thrombosis.

METHODS

A retrospective cohort study was performed at the North Carolina Children's Hospital from 2009 to 2012. Chart review was performed with extraction of patient characteristics and line-related variables. Presence of symptomatic catheter-associated venous thrombosis was the primary outcome. Bivariable analysis and multivariable logistic regression were used to explore associations between line-related variables and thrombosis.

RESULTS

A total of 1135 lines were placed in 815 patients for 118,023 catheter-days. Thirty-six were complicated by venous thrombosis (3.2%) yielding a rate of 0.3 events per 1000 catheter-days. In multivariable analysis, increasing age (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.03-1.13; P=.002), renal dialysis (OR 3.2, 95% CI 1.09-9.66; P=.035), and a diagnosis of inflammatory bowel disease or short bowel syndrome (OR 4.3, 95% CI 1.2-15.0; P=.02) were associated with increased risk of thrombosis. Modifiable risk factors, such as line site, size, and lumens, were not significantly associated with thrombosis. No thromboembolic events were observed.

CONCLUSIONS

We observed a lower incidence rate of catheter-associated venous thrombosis than in most previous reports. No modifiable characteristics altered the risk of thrombosis. Additional investigation of measures to prevent thrombosis is warranted in higher-risk populations, such as patients undergoing dialysis or patients with inflammatory bowel disease.

Central venous access device (CVAD) complications in Haemophilia with inhibitors undergoing immune tolerance induction: Lessons from the international immune tolerance study

INTRODUCTION

Central venous access devices (CVADs) are frequently required as stable long-lasting venous access in children with haemophilia, especially those requiring immune tolerance induction (ITI) for inhibitors. CVAD infection is one of the most frequently reported catheter-related complications in this patient population.

AIM

Detailed review of CVAD complications from the International ITI (I-ITI) study and analysis of potential risk factors for such complications.

METHODS

Retrospective analysis of prospectively obtained data from the I-ITI study primarily focused on CVAD-related complications.

RESULTS

A total of 115 children were recruited and 183 CVADs were placed in 99 subjects resulting in 121,206 CVAD-days observed on-study. A total of 124 CVAD infections were reported in 41 of 99 (41%) subjects with an overall infection rate of 0.94 per 1000 CVAD-days (interquartile ranges 0-1.7). A similar number of infections were observed in the two treatment arms (median: 2 and 3 in high dose and low dose respectively). Infections occurred more frequently in the presence of external catheters than with fully implanted catheters (P = 0.026). Infected patients were significantly younger at the time of CVAD insertion (median age: 22 vs. 25 months, P = 0.020). Patients with Gram-positive infections were also significantly younger than those with Gram-negative infections (median age: 17 vs. 25 months, P < 0.0001).

CONCLUSION

CVAD infection was the most common complication observed in children with severe haemophilia and inhibitors in the frame of the I-ITI study. Younger age at CVAD insertion and external CVAD were associated with higher risk for infection. ITI outcome was unaffected by CVAD infections.

Central venous access devices in patients with hemophilia

Hemophilia is a hereditary disorder in which the major clinical manifestation is bleeding into the joints, muscles, internal organs and the CNS, often without any obvious trauma. Bleeding can be fatal as in the case of CNS hemorrhage, or severely debilitating following repeated bleeding into joints that results in crippling arthritis. Treatment for hemophilia includes the intravenous administration of clotting factor concentrates to replace the missing or defective protein. Venous access is therefore critical to the treatment of hemophilia and the prevention of complications due to bleeding. According to the US Centers for Disease Control and Prevention, approximately half of patients less than 16 years of age and one-third of all patients with hemophilia receive regular prophylactic injections of clotting factor concentrates. Prophylaxis, or the regular scheduled administration of antihemophilic factor concentrate, is effective in preventing bleeding. Among those patients with severe disease, in the absence of prophylaxis, approximately 13 bleeds, including nine joint hemorrhages, occur annually. In contrast, when prophylaxis is administered, the annual number of total and joint bleeds decreases to five and three, respectively. One of the major barriers to the more wide-spread use of prophylaxis is venous access. While peripheral venipuncture remains the first choice for venous access, central venous access devices are frequently used to facilitate repeated and/or urgent administration of clotting factor concentrates. The advantages of central venous access devices are well recognized in certain treatment regimens such as prophylaxis and immune tolerance therapy, as well as certain patient groups such as young children in whom venipuncture is often difficult and traumatic, and adults with scarred veins. Central venous access devices also allow earlier commencement of both home treatment and prophylaxis. The goal of this review is to discuss the different types of central venous access devices and their role in the management of hemophilia to provide practitioners that care for patients with hemophilia with the necessary information to make sound therapeutic recommendations to their patients.

Venous access in haemophilic children: choice and management

Current haemophilia treatment in children is based on regular intravenous infusions of concentrates for prolonged periods, according to prophylaxis regimens or immune tolerance induction treatment, in cases of inhibitor development. Therefore, a stable and uncomplicated venous access is required and as such peripheral veins represent the preferred option. However, frequent infusions in the home setting can be problematic in very young children and for this reason, central venous access devices (CVADs) have been widely used to improve treatment feasibility. Unfortunately CVADs' use is associated with a high rate of complications, and infections and thrombotic occlusion can influence treatment outcome by causing unwanted treatment interruption. CVADs can be grouped into three main categories: external non-tunnelled, external tunnelled and fully implantable devices known as ports. The management of CVADs at home often represents a challenge because a strict adherence to sterile procedures is required. Indeed, the incidence of infections with ports is much lower than that reported for external devices; however, ports carry the inconvenience of needle sticks. More recently, arteriovenous fistula was shown to be a suitable alternative to CVADs because it is easy to use and is associated with a lower rate of complication.

Side-effects and venous access issues with immune tolerance therapy

Immune tolerance therapy (ITT) is the most effective approach to eradicate inhibitors in patients with haemophilia who develop high-titre inhibitors. Yet ITT is associated with many adverse side-effects. Rarely, adverse side-effects arise from the various factor concentrates that patients on ITT receive or from adjuvant immunosuppressive agents used during ITT. Most adverse side-effects of ITT are related to the need for frequent and repetitive venous access, which often results in the need for central venous access devices (CVAD). These devices greatly facilitate the ability to give repeated doses of factor concentrates to patients and are particularly useful in young children who often have small and poorly functioning peripheral veins. These devices can become infected, can malfunction or can lead to venous thrombosis. These complications, although rarely causing mortality, may lead to significant morbidity including the need to have the devices removed and new ones inserted. As well, such CVAD complications may lead to reduced effectiveness of ITT through interruptions in ITT.

Barriers to primary prophylaxis in haemophilic children: the issue of the venous access

Modem treatment for hemophilic children is based on prophylaxis and immune tolerance induction (ITI). Both treatment regimens are based on frequent infusions at early ages, therefore an adequate venous access is essential. Peripheral veins represent the best option, however, different solutions, as central venous access devices (CVADs) and arteriovenous fistulae (AVFs), can be adopted if needed. CVADs have been used in hemophiliacs, however their survival is affected by infectious complications. Among CVADs, fully implantable devices are usually preferred to external lines due to a lower infectious risk. The limited survival of CVADs may have a relevant impact on treatment outcome, especially in case of ITI where treatment interruptions are counterproductive. To overcome such drawbacks, internal AVF has been considered as an alternative option owing to a lower rate of infectious complications. Moreover, AVF is easy to use in the home setting and well accepted by children. Possible complications not preventing AVF use are postoperative hematoma and transient symptoms of distal ischemia; one case of symptomatic thrombosis has been reported so far. Long-term complications include loss of patency, aneurysmatic dilatation and, rarely, limb dysmetria and a regular follow-up is mandatory to allow early remedial intervention. Surgical dismantlement of AVF is recommended as soon as transition to peripheral veins is possible.

Therapeutic use of arteriovenous fistula in children with haemophilia

Haemophilia is an X-linked inherited bleeding disorder, which only affects males. Contemporary treatment of children with haemophilia requires adequate venous access for the administration of prophylactic therapy which commences as a relatively early age. In the majority of children this treatment is administered at home, usually by the parents and then, once competent, by the boys themselves. As venous access in young children is fraught with difficulty, central venous access devices have become the mainstay of haemophilia care. However, these devices come with their own difficulties, with infection and thrombosis causing significant side-effects in some children. Small but substantial cohorts of boys with haemophilia develop antibodies (or inhibitors) to coagulation factors, rendering them both more likely to experience bleeding and more complex to treat. These boys are, for reasons not yet fully understood, more likely to experience central line infections, which also affect overall treatment outcomes. Arteriovenous fistulae were used in four such boys in an attempt to eliminate central line infection and to enable continued treatment administration. The experience and outcomes of these four boys is discussed along with considerations and implications for nurses caring for them.

Haemophilia in the first years of life

Surgery in infants and young children with haemophilia, when preceded by accurate diagnosis and accompanied by safe and effective factor prophylaxis, is not associated with a significant risk of haemorrhage. Haemophilic newborns undergoing circumcision or major surgery prior to diagnosis and in the absence of appropriate haemostatic prophylaxis remain as a concern. Inhibitor development has replaced haemorrhage as the major surgical complication in the developed world, largely because of the intensity of treatment used to secure haemostasis. For that reason only, essential surgery should be performed. Intracranial haemorrhage (ICH) during the neonatal period affects 3.5-4.0% of all haemophilia boys in countries with a good standard of health care, which is considerably (40-80 times) higher than expected in the normal population. Because of the high frequency of sporadic cases, ICH in the neonatal period can only be partially prevented by improved carrier diagnosis and counselling. Infections and thrombosis are the major serious complications of central venous lines. Large differences are seen in the frequency of these complications, the most plausible explanations are probably related to the protocol used for device care, the quality of education and the compliance of the users, an issue addressed in an on-going study.

Tissue plasminogen activator to prevent central venous access device infections: a systematic review of central venous access catheter thrombosis, infection and thromboprophylaxis

The recent unequivocal demonstration that prophylaxis, three to four weekly factor infusions, is effective in preventing joint disease in children with haemophilia, has provided impetus to initiate prophylaxis early in such children. Yet, nearly a quarter (22%) of the 83% who required central venous access devices for factor infusion developed central venous access catheter (CVAD)-related infection. This limitation of CVAD use prevents many families from initiating prophylaxis. The frequent occurrence of local thrombosis accompanying CVAD-related infection in surgical patients and autopsy cases, the thrombogenic plastic CVAD surfaces, and local clot formation at the insertion site, suggest the potential role of thrombolytic agents in preventing these infections. Yet, correlation between CVAD-related infection and local thrombosis in children with haemophilia are lacking, and thromboprophylaxis to prevent CVAD-related infection is controversial. Tissue plasminogen activator (t-PA), a recombinant serine protease glycoprotein that lyses plasmin-bound fibrin and is safe and effective in the treatment of occluded catheters, has not been evaluated in the prevention of these infections. We performed a literature review of CVAD-related infection, CVAD-related thrombosis, and thromboprophylaxis studies to evaluate the role of t-PA in the prevention of these infections in children with haemophilia. Metanalysis of published thromboprophylaxis trials demonstrate current prophylaxis regimens do not prevent CVAD infection, and further, that thrombosis and infection do not necessarily occur simultaneously. Pilot data demonstrate CVAD infection reduction in haemophilic children by monthly t-PA in 18 haemophilic children, suggesting the potential role of t-PA in CVAD infection prevention. Clinical trials to evaluate t-PA in CVAD infection prevention are justified.

The risk associated with indwelling catheters in children with haemophilia

Infections are the most frequent complications associated with the use of central venous lines (CVLs) in children with haemophilia. Several retrospective studies that include data from a substantial number of patients have reported approximately 0.2-0.3 infections per 1000 catheter-days (mainly Port-A-Cath). Some studies have shown a much higher frequency of infections, 1-2/1000 catheter-days. The most plausible explanations, for the difference seen in frequency of infections with Port-A-Caths, are probably related to the protocol used for the device care and the quality of education and the compliance of the users, whether these are parents or health-care professionals. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not performed in most of these series. In studies, where this has been performed, a high frequency of abnormalities (>50%) on venograms have been seen in some series but not in others. Despite obvious potential risks with CVLs, they are useful in many cases and facilitate the treatment of a serious disorder. With careful guidelines and surveillance protocols, the risk of complications should be reduced in the future.

Overview of the use of implantable venous access devices in the management of children with inherited bleeding disorders

Frequent infusion of factor concentrates may be challenging in young boys with haemophilia, especially if their disease is complicated by inhibitors. A central venous access device (CVAD) is often placed in young patients in need of repeated infusions for prophylaxis or immune tolerance induction. Although user friendly and capable of providing reliable venous access, these devices are associated with a high complication rate over time. In the haemophilia population, major complications include CVAD-associated infections and deep venous thrombosis, which is most often silent. Established risk factors for catheter-related infection include age less than 6 years at the time of CVAD placement and use of an external CVAD when compared with a totally implantable device such as a port. Avoidance of CVAD-related infections is facilitated by strict adherence to aseptic technique. The risk of deep venous thrombosis appears related to the duration for which the catheter is in place, with the risk increasing beyond 4 years. The promotion of a strict clinic policy in which CVADs are left in place for as short a time as possible should decrease the risk of complications. In rare cases where a totally implantable CVAD cannot be placed for technical reasons, an arteriovenous fistula may provide reliable venous access. In all cases, however, venous access via peripheral veins is preferred over CVADs.

Inadvertent anticoagulation of a haemophiliac child with routine line flushing

We report the case of a 3-year-old boy with severe haemophilia A presenting with recurrent haemarthroses despite daily infusions of factor VIII delivered through a central venous access device (CVAD). Regular rinsing of the CVAD with heparin, according to a standard protocol, resulted in systemic anticoagulation, as demonstrated by prolonged thrombin time and therapeutic anti-Xa levels. The bleeding symptoms resolved after replacing heparin with a normal saline solution. This case illustrates that heparin administered to maintain CVAD patency should be used with caution in young haemophiliacs. Prolonged thrombin time should alert the physician to this possible CVAD complication.

Fatal central venous catheter-related infection in haemophilia

Central venous catheters (CVC) are frequently used in children with haemophilia to deliver factor infusions for the treatment or prophylaxis of bleeding. Complications of CVCs in patients with haemophilia include thrombosis and infection. We report a young boy with severe haemophilia A and an inhibitor who developed disseminated Staphylococcus aureus infection most likely related to a CVC. To our knowledge, this is the first reported case of fatal sepsis secondary to a CVC in a patient with haemophilia.

Prophylactic factor replacement in hemophilia

Prophylaxis, the regular infusion of coagulation factor concentrates to severe hemophiliacs, has been an evolving therapeutic tool of management for the past three decades. Multiple clinical trials have and continue to be conducted in the field of prophylaxis in an attempt to determine ideal regimens of prophylaxis, its benefits, its risks and costs, and to address still unanswered questions; who to place on prophylaxis, when to start prophylaxis, when (if ever) to stop prophylaxis, etc. We present a detailed review and discussion of the evolution of prophylaxis as a tool in managing patients with hemophilia and we address the major issues and still unanswered questions.

Consensus recommendations for use of central venous access devices in haemophilia

Venous access is essential for delivery of haemophilia factor concentrate. Wherever possible, peripheral veins remain the route of choice, and the use of central venous access devices (CVADs) should be limited to cases of clear need in patients with caregivers able to exercise diligence in CVAD care and should continue no longer than necessary. CVADs are of recognized value for repeated administration of coagulation factors in haemophilia, particularly for prophylaxis and immune tolerance therapy and in young children. Evidence to guide best practices has been fragmentary, and standardized methods for CVAD usage have yet to be established. We have developed management recommendations based upon available published evidence as well as extensive clinical experience. These recommendations address patient and CVAD selection; CVAD placement, care and removal; caregiver/patient guidance; and complications, including infection and thrombosis. In the absence of inhibitors, ports are recommended, primarily because of fewer associated infections than with external catheters. For patients with inhibitors, ports also appear to be associated with fewer infections. Infection is the most frequent complication, and recommendations to prevent and treat infections are supported by extensive clinical data and experience. Strict adherence to handwashing and aseptic technique are essential elements of catheter care. Evidence-based data regarding the detection and treatment of CVAD-related thrombotic complications are limited. Caregiver education is an integral part of CVAD use and the procedural practices of users should be regularly re-assessed. These recommendations provide a basis for sound current CVAD practice and are expected to undergo further refinements as new evidence is compiled and clinical experience is gained.

Central venous catheters in children with haemophilia

Infections, thrombosis and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There seem to be two major experiences concerning infections in non-inhibitor patients, one is approx. 0.2 infections per 1000 days and the other approx. 1.0(0.7-1.6)/1000 days. Infections are more frequent in inhibitor patients and one can expect approx. one infection per 6-12 months of use. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not done in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms have been seen in some but not in others. The final decision to use a central line has to be a compromise between the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia center. Some of the complications may be reduced by adequate aseptic measures both during implantation and in the subsequent use and clear basic routines for surveillance of the systems and repeated education of the users.

Home management of haemophilia

The demonstrated benefits of home care for haemophilia include improved quality of life, less pain and disability, fewer hospitalizations, and less time lost from work or school. Although reduced mortality has not been demonstrated, the substantial increase in longevity since the early 1980s correlates with the introduction of home treatment and prophylaxis programmes. These programmes must be designed and monitored by haemophilia treatment centres (HTC), which are staffed with professionals with broad and complementary expertise in the disease and its complications. In return, patients and their families must be willing to accept the reciprocal responsibilities that come from administering blood products or their recombinant equivalents at home. Patients with inhibitors to factors VIII or IX pose special challenges, but these complications do not obviate participation in home care programmes. Home care was an essential prerequisite to the introduction of effective prophylactic factor replacement therapy. Prophylaxis offers significant improvements in quality of life, but requires a substantial commitment. The use of implantable venous access devices can eliminate some of the difficulty and discomfort of peripheral venous access in small children, but brings additional risks. The future holds the promise of factor concentrates for home use that have longer half-lives, or can be administered by alternate routes. Knowledge of patient genotypes may allow treatments tailored to avoid complications such as inhibitor development. Gene therapy trials, which are currently ongoing, will ultimately lead to gene-based treatments as a complement to traditional protein-based therapy.

Bacillus cereus central line infection in an immunocompetent child with hemophilia

Bacillus species are increasingly recognized as pathogens in immunocompromised patients. The authors report a case of Bacillus cereus infection of a central line in an immunocompetent patient with hemophilia, which required line removal for complete cure.

Central venous access devices in haemophilia

Central venous access devices (CVADs) can facilitate repeated and/or urgent administration of coagulation factors in haemophilic patients. We conducted a systematic review and meta-analysis of complication rates and risk factors for poor outcome. Forty-eight studies with a total of 2704 patients and 2973 CVADs were included. The primary indications for CVADs were immune tolerance therapy (34.9% of patients), difficult venous access (31.8%) and prophylaxis (29.1%). Fully implanted CVADs were employed in 77.4% of cases and external CVADs in 22.6%. A total of 1190 infections were reported, and the pooled incidence of infection was 0.66 per 1000 CVAD days [confidence interval (CI), 0.44-0.97 per 1000 CVAD days]. Among patients developing infection, the pooled time to first infection was 295 days (CI, 181-479 days). Presence of inhibitors was an independent risk factor for infection with an incidence rate ratio (IRR) of 1.67 (CI, 1.15-2.43). Infection was less likely in patients >6 years of age (IRR, 0.46; CI, 0.27-0.79) and recipients of fully implanted CVADs (IRR, 0.31; CI, 0.12-0.86). Available information on thrombosis was limited, with only 55 cases being reported. Eventually, 31.3% of CVADs were removed, and infection was the reason for removal in 69.9% of cases and thrombosis in 4.1%. The pooled time period CVADs remained indwelling prior to removal or the expiration of the study observation period was 578 days per CVAD (CI, 456-733 days per CVAD). CVADs can confer major benefits in patients with haemophilia requiring long-term venous access, and serious complications are rare.

Long-term safety and feasibility of arteriovenous fistulae as vascular accesses in children with haemophilia: a prospective study

Infectious and thrombotic complications limit the long-term use of subcutaneous ports as venous accesses for children with haemophilia. This study has evaluated for the first time the safety and feasibility of internal arteriovenous fistulae (AVF) as alternative accesses. During the 3-year study period, 27 severe haemophiliacs, 14 with factor VIII inhibitors (52%), underwent the creation of 31 proximal AVF in the forearm. Mild forearm haematomas were observed after five procedures (16%) in five patients who had or developed inhibitors after surgery. Inadequate AVF maturation was observed after five of 31 procedures (16%) in four children. AVF were first accessed after a median of 42 d and regularly used at home by 26 patients (96%) for a median follow-up period of 29 months. Thrombosis of a venous branch occurred in one AVF (3%) after 9 months of uncomplicated use in a child with inhibitor who spontaneously recovered from the symptoms and still used AVF for nine additional months. Mild symptoms, referable to distal ischaemia, were transiently reported by two children (7%) who needed no remedial intervention. This study demonstrates that the use of AVF in haemophiliacs enabled long-term treatment at home in all patients but one.

Surveillance of infectious complications associated with central venous access devices in children with haemophilia

PURPOSE

To analyse the risk factors for infection associated with central venous access device (CVAD) use in children with haemophilia.

METHODS

Risk factors for CVAD infection among patients with congenital haemophilia who had had a CVAD implanted at a single institution were evaluated utilizing the following variables: age at CVAD placement, age at end of study, number of days with a CVAD, percentage of lifetime with a CVAD, and history of inhibitor.

RESULTS

Fifty-nine patients had a total of 97,936 (median 1768 days per patient) CVAD days in the study period. The median age at CVAD placement was 2.7 years (range 0-14.0). Twenty-six (44%) patients reported CVAD infections during the study period from January 1993 to October 2000. Twenty-four patients had their CVAD replaced, 17 (71%) of whom reported having infections and seven (29%) of whom had a history of inhibitor. The strongest predictor for having any infections was inhibitor status (P=0.16), although none of the risk factors had statistically significant effects. Among the 26 patients reporting infections, 42% had more than one CVAD-related infection. Seven patients had multiple infections involving the same organism. The mean rate of infection was 0.45 per 1000 catheter days, with a 95% confidence interval of 0.33-0.60. Those with a history of inhibitor had an infection rate of 0.66 compared with 0.38 per 1000 catheter days (P=0.09) for those without a history of inhibitor. Patients who were older (greater than the median age of 2.7) at CVAD placement had a lower rate of infection (0.29 vs. 0.65, P<0.01) compared with those < or =2.7 years. Adjustment for inhibitor status had little impact on these results. For the group as a whole, the median time to first infection was 1977 days from CVAD placement. Patients who were older at CVAD placement or study exit had lower relative hazards of infection (P=0.05 and P=0.09 respectively), while those who had inhibitors had a higher but not statistically significant relative hazard of 1.88 (P=0.13).

CONCLUSIONS

These data reveal that while considerable numbers of patients develop CVAD-related infection, the interval between catheter placement and infection can be quite long. In addition, the earlier in life a CVAD is placed, the higher the risk of infectious complications, as evidenced by the tendency towards a higher infection rate. Measures to prevent CVAD-related infection might be focused on very young patients who appear to be at higher risk.

Central venous lines in haemophilia

Infections and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There are two major experiences reported concerning infections in noninhibitor patients: one is approximately 0.2 infections per 1000 days and the other approximately 1.0 (0.7-1.6) per 1000 days. Infections are more frequent in inhibitor patients and approximately one infection per 6-12 months of use can be expected. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not carried out in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms has been seen in some but not in others. The final decision to use a central line has to take into account the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia centre. Some of the complications may be reduced by adequate aseptic measures both during implantation and in subsequent use, and by clear basic routines for surveillance of the systems and repeated education of the users.

Experience with a new percutaneous port system, Percuseal, for intravenous injection in patients with haemophilia, von Willebrand disease and severe alpha1-antitrypsin deficiency

We have implanted a new port system (Percuseal) in altogether 13 patients with haemophilia A, B, von Willebrand disease and alpha1-antitrypsin deficiency in order to facilitate venous access. The Percuseal system differs from subcutaneous ports, such as Port-a-Cath, in that the upper part of the device protrudes above the skin. In this way, the patient can easily puncture the port membrane under the guidance of his eyes without penetrating the skin. In the present study cohort, a number of complications occurred. These were mainly caused by repeated local infections (in five patients), which made it necessary to replace the ports in three of the patients and to permanently remove the ports as the first option in two of the patients. In one patient, the port was removed because of inconvenience when doing physical exercise. In one additional patient, a severe systemic infection occurred, causing spondylitis. Despite the high infection rate, most patients considered the device very convenient to use. Because of the side-effects seen in our study, the Percuseal port in its present form is not to be recommended for regular use. A reconstruction of the port, making it smaller and giving it an antibacteriostatic cap, may possibly make this kind of port system a feasible alternative to use in order to improve pharmacoeconomics in the prophylactic treatment of haemophilia and patients with alpha1-antitrypsin deficiency.

Complications of central venous access devices in paediatric haemophilia patients

We conducted a retrospective survey of our experience with central venous access devices (CVADs) implanted in children with haemophilia seen at the Vanderbilt Hemostasis-Thrombosis Clinic from 1986 to 2000. Following discussion with parents on the merits and risks associated with the use of CVADs for immune tolerance induction or factor prophylaxis, catheters were inserted under sterile technique in the operating room. One nurse provided demonstration and teaching about catheter care and access. Thirty central venous catheters were inserted in 22 children. Our survey revealed that the two most common complications associated with central venous catheters were bacteraemia and thrombosis. We found a sepsis rate of 0.30/1000 catheter-days or one episode of bacteraemia for every 3346 days of catheter use. The thrombosis rate of our cohort was 0.13/1000 catheter-days or one episode of thrombosis for every 7529 days of catheter use. Uncomplicated venous access is essential in children with severe haemophilia who require prophylaxis or immune tolerance induction. While infection was the most common complication observed in our series, we experienced a lower overall infection rate than several reported series. Catheter thrombosis and subsequent obstruction may occur as a result of intraluminal fibrin deposits. We conclude that the use of implantable central venous catheters is an effective method for accessing children with haemophilia. We accept that the benefits of CVADs in the treatment of paediatric haemophilia patients outweigh the previously documented risks. Future prospective studies should be designed to define all associated risks and to determine effective strategies to reduce them.

Paediatric care of the child with haemophilia

The paediatric care of children with haemophilia in developed countries should focus on the health of the child, not on the disorder. Gene therapy offers the hope of an ultimate 'cure' for the disorder, but until this is a viable proposition, patients should be given more control over their treatment, and the focus should be on 'self-monitored and self-adjusted' prophylaxis. New instruments for measuring joint function and radiographic changes, and quality of life are valuable tools in improving the treatment of paediatric care for children with haemophilia.

Complications of central venous catheters in patients with haemophilia and inhibitors

We report our clinical experience with central venous catheters (CVCs) in 15 patients with haemophilia who, in total, had 34 catheters inserted. Eighteen devices were Hickman, six were Port-A-Cath and 10 were nontunnelled catheters (one Quinton, seven antecubital, one jugular and one subclavian vein access). All patients had factor VIII/IX inhibitors at the time of insertion. The mean age at operation was 8.8 years (range 16 months-39 years). Eight of the 15 patients (26/34 implanted catheters, 76%) presented some kind of complication. Pericatheter bleeding during the postoperative period affected a total of seven CVCs (7/34, 20%) in six patients, which required substitutive treatment for several days. Infection was reported in 15 of the CVCs (15/34, 44%), and four of these (4/15, 26%) had more than one episode, with a mean of 1.4 infection episodes per catheter (21/15). The infection rate was 0.2 infections per 1000 patient days or 0.1 per 1000 catheter days. Despite the usefulness of CVCs in haemophilic patients, the high incidence of complications requires careful assessment of the type of device as well as continuous surveillance.