ABSTRACT
The cranioplasty for the correction of defects caused by surgical trepan is one
of the problems that is not properly solved in neurosurgery. Frequently, the
patients complain during postoperative period about the depressions left by the
neurosurgical trepan in the craniotomy. The extensive gamma of aloplastic
materials that has been considered and used for this end is a good example of
this difficulty. The bone dust, frequently used in these reconstructions, suffers a
high reabsorption degree, but until the moment, this absorption had not been
mesured, nor compared to the one of the cortical bone. Another great challenge
that has not been solved yet until the moment is the difficulty to access the
biological development of transplanted bones in human beings, something that
disabled the results quantification. The place reconstruction evaluation through
inspection and palpation is a coarse method of gauging and allows only a
subjective qualitative analysis. Our insatisfaction with the cranioplasties
aesthetic result and the lack of objective measures of the bone imperfections
made us test the use of bone autogenous graft of the internal calvarial bone
blade as a aesthetic-functionary resolution for the deformities caused by
neurosurgical trepan. Twenty three adult patients submitted to the surgery due
to varied causes (ragged aneurism, not ragged aneurism, arteriovenous
malformation and benign neoplasia) had had the trepanation orifices
reconstructed with autologous bone dust or a autologous bone circular took
from the internal blade of the bone segment removed for the intracranium
procedure. In the same pacient, the two types of reconstruction had been
carried through. The bone dust was collected during trepanation with a trephine
especially confectioned by the author for this end. After eight months, we have
carried through a tomography of the cranium that had bone reconstruction. The
places reconstructed with dust of bone and with bone fragment had been
delimited and they had had the bone density gauged by means of cranium
computerized tomography, procedure still not used in the practical
neurosurgical clinic. The results were expressed in Hounsfield units (HU). The
reconstructions were evaluated by two different specialists, blinded for the
study, who attributed a grade from 0 to 10 for the aesthetic appearance of the
reconstructed places. We analyzed the correlation between the grade attributed
for the appraisers with the density measured for the CT. 108 orifices of
craniotomy in the 23 studied patients were reconstructed, among those 36
orifices were reconstructed with circular fragment from the internal blade
(33,3%) and 72 with bone dust (66,6%). The mean density of the
reconstructions with circular fragment was 987.01 ± 172,6 UH, while the one of
bone dust was 464,46 ±197,66 UH. This difference was significant in a
statistical way (p< 0.001, paired t-test α < 0,05). The average grade attributed to
the reconstructions by the appraisers was of 9,5 to the bone fragment and 5,7
to the bone dust, (p< 0.001. paired t-test α < 0,05). It had not occurred
complications during the pursuing of up to 25 months. In the end of the study, it
can be concluded that the autologous bone fragment of the internal blade is
superior to the dust of bone for the reconstruction of trepanation orifices. The
absorption of bone fragment is smaller and its aesthetic characteristic is
superior. The null cost, as well as the absence of morbidade of donor place,