Comparison with other studies and clinical implications
Within the limitations of the retrospective data which are discussed
below, the outcomes of the initial treatment approach were evaluated and
compared. The rates of revision surgery were similar across the four
groups with approximately a half of patients requiring second operation
after 5 days due to progression of intracranial abscess. Notably, 9 out
of 15 patients were successfully treated with sinus drainage thus
avoiding a craniotomy. While we recognise that there was a trend of
larger intracranial abscesses found in patients treated with
neurosurgical drainage, the findings suggest that ENT only interventions
may have a role in reducing the number of patients undergoing a
craniotomy and its associated morbidity. The key question remains as to
which patient group is most suited for this approach. Garin et al. have
previously reported that the presence of SDE was a contraindication to
endoscopic sinus surgery (ESS) only approach as 87% ultimately required
a craniotomy[9]. On the contrary, 3 out of 4 patients with EDA were
successfully managed with ESS alone. In the present study, we found that
that 60% of patients managed with sinus interventions only did not
require a craniotomy despite the high proportion of patients with SDE
(60%). This begs the question whether factors other than the type of
intracranial abscess has more deterministic effect on the need for
revision surgery. Indeed, in the univariate logistic regression analysis
we found that the size of an intracranial abscess (≥10mm) had the
strongest prediction for the need to return to theatre, while the
presence of SDE was not found to be significant. Our results are in
contrast with those reported in the study by Gitomer et al.[14],
which found that the presence SDE was the key predictor for the need to
return to theatre, however the authors did not include the size of an
abscess in the analyses. Therefore, it remains to be determined whether
patients with small intracranial abscesses including SDE may be suited
for ESS only. Non-operative initial treatment with close observation may
also be an option. Three out of 4 patients in our cohort were
successfully managed with intravenous antibiotics alone. None of the
patients had neurological disability and had markedly shorter hospital
stay (median 12.5 days). However, no firm recommendations can be made
regarding the indications for conservative treatment.
Irrespective of the initial approach, two thirds of our cohort underwent
neurosurgical intervention at some point during the inpatient stay.
While ESS may prevent the need for a craniotomy in some patients, its
role when used in conjunction with neurosurgical intervention is
controversial. We found that two thirds of patients required revision
surgery despite a joint neurosurgical and ENT approach, the highest
proportion when compared to the other treatment arms. Combined treatment
was also not found to affect the rates of revision surgery, neurological
disability and hospital length of stay. As mentioned before, inherent
selection bias may be responsible for the lack of apparent benefit of
combined procedures, however the clinical and disease characteristics
were largely comparable across the treatment groups as summarised in
table 5. The current study findings are also consistent with the results
from previous studies in adults[13,17]. In a retrospective cohort
study on 255 adult patients with sinogenic intracranial suppuration,
Koizumi et al. investigated the effects of ESS in addition to
neurosurgical drainage[17]. The authors did not find that ESS
resulted in an improvement in any of the study outcomes including
mortality, requirement for blood transfusion, revision surgery,
readmission and the LOS. These findings raise an important question as
to whether sinus interventions, which can be more technically
challenging in children are warranted in the acute setting considering
the likelihood of increased operative time, bleeding and orbital injury.
This is particularly relevant in centres where rhinological expertise
may not be available. Some authors argue that ESS may serve as an
important diagnostic tool by enabling the surgeon to obtain
microbiological samples[9]. However, in the present study we found
that in only 3/20 cases intracranial samples did not yield a culture
growth and the wash out from the sinuses provided microbiological data
instead.
The present study found significantly increased risk of ND in patients
treated with neurosurgery alone (75%) when compared to ENT only
interventions (6.7%). The findings should be interpreted with caution
due to the limited cases in the neurosurgery group (n=4). This
observation is most likely as a result of a considerable difference in
the median size of an intracranial abscesses across the groups (median
10mm in the neurosurgery vs. 5.5mm in the ENT only), although not
statistically significant.
Finally, three deaths were observed in our cohort, two of which were in
the ENT only group. All three patients presented with severe sepsis. One
patient was deemed too unwell to undergo a craniotomy and only antral
wash out was performed. In a second patient, the abscess was located in
the pons and was not surgically accessible. A third patient passed away
from the complications related to sepsis despite a craniotomy and antral
wash out.