Demand for radiologically inserted vascular access devices in children is increasing.
The most common paediatric vascular access device inserted by an interventional radiologist is the PICC. However, according to Krishnamurthy et al. [4], TCVCs last longer than PICCs and are preferred when access is required for more than 6 weeks duration. In a recent retrospective cohort study conducted by Kovacich et al. [12] looking at PICC-associated complications in children requiring long-term parenteral antibiotic therapy, there was an overall complication rate of 4.6 per 1000 catheter days, with catheter occlusion and dislodgement being the most common reasons for premature PICC removal. On the other hand, there are many institutions that use PICC devices for long-term paediatric venous access, and there are some data to support PICC devices having fewer complications than TCVCs. Blotte et al. [13] carried out a retrospective analysis comparing the complications of Broviacs® TCVC and PICCs in children with intestinal failure receiving parenteral nutrition. When comparing catheters with the same diameter, there were no significant differences in infection or breakage rates. However, a lower incidence of central venous thrombosis with the use of PICCs is suggested. This correlates with evidence in the literature, where risk factors for central venous thrombosis include catheter size, location of the catheter tip and associated catheter complications. Another prospective randomised study by Cowl et al. [14] found no difference in rates of infection, occlusion or dislodgement when comparing PICCs with subclavian central catheters.
However, their use is associated with frequent complications resulting in premature catheter removal [1]. Infectious complications include exit site or port infection, tunnel infection and microbial colonisation of the catheter (defined by either positive culture from the CVC with negative peripheral blood culture, or positive catheter tip culture). Mechanical complications include inadvertent dislodgement, catheter fracture, occlusion and venous thrombosis [3]. Image guidance has been found to increase procedure success rate and decrease acute complication rates.
The 4.8% incidence (1.2 per 1000 catheter days) of suspected microbial colonisation reported in our study is in the lower range of reported rates in the literature. Garcia-Teresa et al. [15] in a multicentre prospective study examining children in a paediatric intensive care unit (ICU) aged 0–14 years report a catheter-related blood stream infection rate of 6.81% or 6.4 per 1000 catheter days. Casado-Flores e al. [16] conducted a prospective study looking at central venous catheterisations in children of different ages in a paediatric ICU and found an infection rate of 5.8%. Cruzeiro et al. [17] in a prospective study of consecutive catheterisations in children in a public hospital report an 11.6% of suspected catheter-related infection.
Multiple studies have also been carried out looking at complication rates of CVCs in neonates, with infection rates varying from 0 to 46% [1, 18,19,20,21,22,23,24,25,26,27]. Battin et al. [27] recently conducted a prospective audit assessing complication rates in a neonatal ICU. In total, 38% of babies showed clinical signs of sepsis while their lines were in situ but only 10% had positive peripheral or line cultures. On the other hand, Ainsworth et al. [18] recently conducted a meta-analysis looking at randomised controlled trials that compared delivery of intravenous fluids via CVCs versus peripheral cannulae in hospitalised neonates. In conclusion, there was no evidence to suggest that percutaneous CVC use increases risks of adverse events, particularly invasive infection.
Dislodgement occurred in only one case (4.8%) in this series, with a rate of dislodgement of 1.2 per 1000 catheter days. We suspect that inadvertent dislodgement occurred during a change of clothes by the child’s parents. The current study identified a rate of dislodgement in the lower range of that reported in previous studies. Central venous catheter dislodgement has been found to be more frequent in younger patients [1]. A retrospective study by Tavis et al. [3] comparing delayed complications of surgically versus radiologically placed CVCs in paediatric oncology patients quotes a rate of dislodgement of 16.7% amongst radiologically placed CVCs. Nosher et al. [28] examining a sample of paediatric CVCs predominantly placed for chemotherapy reported rates of dislodgment at 12% (0.82 per 1000 catheter days). Wiener et al. [29] in a large, multicentre study combining data from ports and CVCs placed for chemotherapy in children reported rates of dislodgement ranging from 2.8 to 24%. This suggests that despite lacking a Dacron cuff and with only a proprietary adhesive anchoring mechanism in place, these non-cuffed devices are reasonably secure. We attribute this infrequent rate of dislodgement to the fact that these tunnelled catheters can be tucked away safely under the child’s clothing and are less likely to get accidentally pulled out in comparison with peripherally inserted catheters.
The results not only indicate our technique to be safe with an acceptable low complication profile, but also offer an advantage of greater convenience in comparison with conventional paediatric TCVCs. Ninety per cent of these catheters lasted for the total intended duration of use and remained in situ until no longer required. It is not clear what is responsible for the apparent security of the device, but experience with this model and brand of adhesive device in adult PICCs suggests that the adhesive device alone provides durable device retention without suturing or the presence of a subcutaneous retention cuff. It is, however, recommended that the adhesive device be replaced expertly when indicated by the state of the dressings. Catheter removal in our technique is less complex. The catheter can be removed simply by pulling it out, and this does not require general anaesthesia because it does not cause any discomfort. Another advantage over standard PICCs is that the device gets tucked away safely under clothing, away from inquisitive fingers. The limitations of the current study include the retrospective non-randomized study design and the modest sample size.
Future prospective studies comparing this novel technique with standard PICCs and conventional TCVCs placed over a similar time period would be of value to confirm equal utility, comparable complication rate and possibly a better cosmetic result in relation to healing of the chest wall scar. Although the subgroup of five patients (24%) who were less than 1 year of age or less than 10 kg in weight were not analysed separately, none of these patients sustained delayed complications in our study population. To the best of our knowledge, although we are aware anecdotally of other units employing similar techniques, we are not aware of any priorly published report describing this simple technique.