Discussion
In this case, we selected a combination of revascularization and skull
base reconstruction. Previously reported ICA rupture cases due to
osteonecrosis were almost recurrent NPC cases, and probably no long-term
prognosis could be expected [1,2,6,8-10]. In contrast, the primary
disease as pituitary adenoma had been stable for a long time. Therefore,
complications after long period of time, such as left ICA rupture,
should be considered when necrotic tissue on the sphenoid bone was not
removed. Hence, we considered that if complete revascularization had
been established, skull base reconstruction with removal of necrotic
tissue would be also necessary to prevent complications for a long time.
Osteoradionecrosis, resulting from a second course of radiotherapy,
affected the right ICA rupture, which might have been caused by
obstruction of the vasa vasorum, premature atherosclerosis, adventitial
fibrosis, and necrosis of the arterial wall [2,7,11]. Although cases
in previous reports typically were accompanied by a pseudoaneurysm
[1,2,6-11], it was not noticeable on conventional angiography in the
current case. Therefore, even with a massive epistaxis, it was difficult
to immediately diagnose the patient with right ICA rupture based only on
angiography results. However, considering the progress of follow-up from
the first visit, it was strongly suggested that epistaxis was caused by
right ICA rupture.
We selected revascularization using high-flow bypass with trapping of
the right ICA. Most authors have argued that endovascular treatment
should be the first choice for ICA rupture with pseudoaneurysm in
situations where patients could tolerate BOT [1,2,6-11]. The success
rate was 87% of endovascular treatment and 33% of high-flow bypass
according to a previous study [1]. However, this case was a peculiar
situation in which it was difficult to evaluate BOT. The patient had
impaired consciousness at the time of the conventional angiography. In
addition, prerequisites for endovascular treatment could not be
identified because there were no findings of pseudoaneurysm or the site
of hemorrhage could be determined. Consequently, revascularization was
performed instead of endovascular treatment. In addition,
revascularization greatly reduced the risk of hemorrhage from the right
ICA during skull base reconstruction. Therefore, surgical manipulations
could be performed safely.
This combination procedure in the current case has some limitations.
High-flow bypass with RA grafting is technically dependent, especially
in emergency situations [1,10]. Additionally, it is necessary to
urgently assemble a cross-departmental team of otolaryngologists and
neurosurgeons: neurosurgeon-otolaryngologist collaboration.
Nevertheless, to rescue this type of cases and obtain the best results,
the combination procedure we performed would be a definitive curative
treatment.