Dear Editor,
We read with great interest the comments of Drs. Teles and Kraemer[1] on our article “The number of burr holes and use of a drain do not interfere with
surgical results of chronic subdural hematomas (CSDH)”. We really appreciated their
attention to our study and contribution to current statements on CSDH treatment.
We agree that standard management of this condition still remains controversial in
its pre-operative, intraoperative and postoperative details[1],[2],[3],[4],[5],[6],[7],[8]. This may be due to complex pathophysiological characteristics of this disorder
and distinct patient profiles in different health institutions. We also recognize
the great value and contribution of the randomized controlled trial (RCT) performed
in 2009 by Santarius et al.[4], in which the use of a drain was effectively associated with a lower rate of recurrence
of CSDH and lower rate of patient mortality[4]. The same author has a commendable list of publications in this regard, reinforcing
the advantages of using a drain[5].
However, it is almost a decade since the publication of the RCT by Santarius et al.,
which was the sole RCT discussing this theme at the time, and more recently, some
newer, respectable publications have brought to our attention the fact that the same
results might not be achieved worldwide. In this regard, Gernsback et al.[7] and Sivaraju et al.[8] have recently reported, in two different respectable neurosurgical journals, that
their results did not match with those found by Santarius et al[4]. In both cases, the use of a drain did not affect recurrence rates[7],[8]. We must highlight that neither of these recent studies were RCTs[7],[8]. Our article had some common points with the Gernsback and Sivaraju studies[6].
Additionally, we understand and agree that our study clearly had some drawbacks, including
the retrospective design, absence of randomization and limited sample size. All these
points may impair the quality of our results and their conclusions. However, as far
as we know, our paper is the best available evidence nationally, and is a realistic
study reflecting our routine management of this disease.
One should remember that even a randomized trial evaluating only one sample produces
internal validity for that sample and several other studied samples or centers would
be needed to create external and generalized validity and evidence. Therefore, rather
than arguing against the results of a RCT, we would like to propose that it is necessary
to comprehend CSDH as a complex disease, with potentially different outcomes depending
on the sample's clinical profiles, technical aspects and regional nuances.
