Discussion
In this study, we examined efficacy of application of
glucocorticosteroid during patch occlusion and subsequently silicone gel
sheet. We hypothesized that the combination of glucocorticosteroid and
patch occlusion would be effective in reducing the development of
hypertrophic scar/keloid after removal of CVC on children and
adolescents treated for neoplastic diseases. We also expected that scar
width and children’s or their parents’ subjective perception of the scar
would be improved by using glucocorticosteroid during patch occlusion.
The results of the VSS assessed by the study nurse were different from
the data from the dermatologist. The study nurse generally assessed VSS
higher than the dermatologist. The VSS is developed to rate burn scars,
but it also has an acceptable internal consistency for linear scars
(Chronbach´s alpha 0.79). The inter-observer reliability is found
substantial (Intraclass coefficient correlation 0.78) [10]. However,
Truong et al. do not describe whether the observer using the VSS should
have dermatological experience [10]. In the present study, the study
nurse was specialized in pediatric oncology as opposed to the
dermatologist, who had considerable experience in assessing scars.
Therefore, data from the dermatologist are considered to be the most
reliable.
Data from the dermatologist showed that the intervention group had a
lower VSS score than the control group 12 months after removal of the
CVC. Common for the two groups in the intervention group (active and
placebo) was the use of sheet occlusion. Both groups had cream applied
under patch occlusion one week before, and three weeks after removal of
the CVC. After three weeks, both groups covered their scar with a
silicone gel sheet for three months, to avoid pull on the scar. Since
the cream received by the two groups was different (placebo and
glucocorticosteroid), the significant lower VSS score may be caused by
the sheet. Future studies may be able to detect the effect more robustly
by including more patients in the intervention groups.
By searching the literature, we found only two papers on CVC cars in
children with cancer. Braam et al. (2015) [6] performed a three-arm
randomized controlled trial. The aim of the study was to evaluate the
effects of using silicone gel sheets on scar outcome after removal of
PAC on children with cancer. Two intervention groups were included; One
received two months of silicone gel sheets application, and one received
six months of silicone gel sheet application. The control group received
no additional care or treatment. No significant improvement of scar
outcome was found when using silicone gel sheets after the PAC removal.
A small benefit for scar width with application for two months was found
[6]. In the present study, both the active and the placebo groups
used a silicone gel sheet for three months and had a better outcome than
the control group. Overall, the intervention group had a significantly
lower VSS score than the control group (p = 0.00). This is supported by
a review investigated the effectiveness of silicone gel and silicone gel
sheeting for the prevention of hypertrophic or keloid scarring on
patients with newly healed wounds. However, they also found that most of
the trials had poor quality with high or uncertain risk of biases in the
design or the conduct [7]. Overall, there is a need for larger
studies and interventions that can distinguish between the effect of
silicone gel sheet and the effect of glucocorticosteroid in combination
with silicone gel sheet.
The POSAS was in combination with the VSS used to assess the scars. The
POSAS consists of an extra dimension because the patients´ opinion is
required for a complete scar evaluation. The patients’ opinion does not
figure in the VSS. The POSAS assessed by the patients and the study
nurse showed that the intervention group had a lower score than the
control group, which is consistent with the results for the VSS assessed
by the dermatologist. However, the differences in the POSAS was not
significant.
The results should be interpreted with caution due to the study
limitations. The study included a relatively small sample size in the
intervention group. A total of 69 patients were assessed for
eligibility, 33 patients were excluded inter alia due to failure to
follow the recommended treatment and relapse. This must be expected when
working with children with cancer.
Another limitation is the fact that the 47 patients in the control group
were collected retrospectively. Therefore, we cannot exclude that the
parents applied a patch in the period following removal of the CVC, but
it was not part of the recommendations from the department. No record
was made whether children covered their scar with a patch after removal
of the CVC. But the probability that they have used a patch with
silicone gel seems small, both because it is not a standard patch and
because it is expensive.
Furthermore, most of the participants had a PAC, which limits the
conclusions that can be derived concerning tunnelled central venous
catheter.