Page 13 - Revista Portuguesa - SPORL - Vol 61. Nº4

et al. focused on the effect of PRP injection posterior portions of the olfactory region. Even
14
in parosmia showing a highly significant though varying with individual anatomy, these
improvement in VAS score. Lechien et al. measurements frame most of our procedures
15
addressed pCIOD patients with anosmia, within the olfactory mucosa region (see Figure
hyposmia and parosmia concluding that both 5). Another important modification from our
psychophysical and subjective measurements protocol, compared to the one used in the
were improved after injection. Interestingly, randomized trial from Yan et al. was the
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Duffy et al. refer to an alternative method of injection timing.
delivering PRP into the olfactory mucosa by
means of PRP impregnated surgifoam instead Figure 5
of submucosal injection . Estimated vertical distribution of olfactory
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Another objective of this work was to describe mucosa at the anterior olfactory septal portion
(white line), based on Escada´s cadaveric
possible PRP injection complications. In line measurements 17. Green dashed lines
with Literature 9,10 , our protocol had a low rate correspond to the virtual vertical divisions of the
of minor complications, with only one case of middle turbinate. In this case, the injection site
was by far inside the olfactory epithelium.
vasovagal reaction. No major complications
occurred, including no cases of early/late
epistaxis or resulting septal defects. Our
unique single-site injection protocol contrasts
with the one from Yan et al. , in which two
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different needle entry points are employed
(the first along the superior septum just
posterior to the head of the middle turbinate
and then again about 1 cm posteriorly into
the septum across from the leading edge
of the superior turbinate). Conversely, in our
single-site injection protocol, the puncture
is only performed anteriorly, where the entry
site can be controlled in the case of epistaxis
(see Figure 3). Besides, virtually delineating
three middle turbinate levels may help to
avoid puncturing dangerously near to the
S-point (see Figure 3). The authors believe this
modification may somehow decrease the risk Yan et al. excluded patients with pCIOD
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of incidental arterial puncture. On the other lasting more than 12 months, since the authors
hand, the single-site injection allows for the believe neuronal regeneration is unlikely to
PRP to dissect submucosally in a posterior and occur after this period. Our cohort showed
superior direction and deposit in situ without a mean of 6.5 months delay from COVID-19
shunting through a second puncture point. infection and first specialized consultation.
Aside from ideal endoscopic accessibility in Additionally, one of our inclusion criteria
the awake patient, theoretical background was medical treatment failure measured
seems to exist to support this anatomical site by at least two consecutive 3-month apart
of injection and submucosal dispersion of PRP. OPT evaluations and pCIOD lasting for ≥ 12
The work from Escada in cadaver specimens months. Consequently, our mean time from
17
found that in the nasal septum, the lower limit COVID-19 diagnosis to PRP injection was 21
of the olfactory mucosa lies at 15.9 ± 3.2 mm, months. Apart from proving effectiveness
15.3 ± 3 mm and 16 ± 2.8 mm from the skull in this setting, our findings showed that the
base, respectively at the anterior, middle and time from COVID-19 diagnosis to injection

Volume 61 . Nº4 . Dezembro 2023 351