Study population
This single-centre retrospective study enrolled 41 patients who
underwent endoscopic modified transseptal pituitary surgery between
April 2018 and December 2019 at our hospital. The main inclusion
criterion was primary/recurrent pituitary adenoma, with olfactory
testing performed both preoperatively and 3 months postoperatively. The
exclusion criteria were endoscopic surgery combined with craniotomy,
endoscopic sinus surgery (ESS) performed intraoperatively/previously
performed, chronic rhinosinusitis (CRS) with/without nasal polyp, and
allergic rhinitis. All surgeries were performed by the same
otolaryngologist (O.K.) and neurosurgeons (I.Y., M.R.). The research
protocol was approved by the institutional ethics committee (Protocol
No. 32-081). Written informed consent was obtained from all patients.
Surgical approach (video 1)
We chose a bi-nostril approach, with the left nostril approaching the
sphenoid sinus via the nasal septum and the right nostril approaching
the sphenoid sinus via the nasal cavity and olfactory cleft. A surgical
field of passage and approach to the sphenoid sinus was devised at our
centre by an otolaryngologist. First, an incision was made in the left
nasal septum mucosa from the anterior superior to the nasal floor. The
mucosa of the left nasal septum and nasal floor was raised from the
nasal septal cartilage and maxillary bone and pulled into the left limen
nasi, allowing a visual field to approach the sphenoid sinus via the
nasal septum. At this time, the greater palatine artery passing through
the canalis incisivus was not dissected (Fig. 1A). Second, septoplasty
was performed with the vomer and perpendicular plate of the ethmoid
removed. At the posterior edge of the nasal septum, an incision was made
from the nasal floor along the upper walls of the right and left choana
to increase the lateral range of motion of the left and right nasal
septal mucosa. The left and right nasal septal mucosa were laterally
deviated, and sphenoidotomy was performed until the bilateral sides of
the optic canal and carotid artery ridges were in the same endoscopic
field of view. (Fig. 1B). Third, the right nasal septal mucosa was
incised horizontally (posteriorly to anteriorly) with the nasal floor
from the upper margin of the sphenoid sinus ostium to the anterior end
of the middle turbinate (Fig. 1C). No turbinate was resected in any of
the cases. The posterior ethmoidal sinus may be opened by endoscopic
ethmoidectomy in cases of pituitary tumours that extend laterally beyond
the cavernous sinus at grade ≥3 according to Knosp
classification.18 A 1 mm-thick silicone plate (KOKEN,
Tokyo, Japan) was placed on the outside of the left and right nostrils
to protect the left nasal septal mucosa and right inferior/middle
turbinate and sewn into the nostrils on both sides. This allows for a
two-nostril, one-cavity approach (Fig. 1D). The sphenoid sinus mucosa,
which we call a local flap, was temporarily peeled off and preserved to
cover the wound finally, and the patient then underwent tumour removal
by the neurosurgical team. After pituitary tumour removal and
confirmation that there was no cerebrospinal fluid (CSF) leak,
osteophyte and mucosal reconstructions with a local flap were performed.
In cases of intraoperative CSF leakage, the horizontal incision in the
right nasal septal mucosa was extended and an NSF was prepared. If an
NSF was not used, the right-sided horizontal incision was sutured with
two stitches using 5-0 TF vicryl. The left-sided septal mucosal incision
line was sutured with three stitches, and the left and right nasal septa
were sutured together with three stitches using 4-0 RB-1 vicryl.
Finally, the left and right nasal septal mucosa were sutured with 5-0
nylon thread to sandwich the silicone plate. Nasal rinsing was initiated
1 week postoperatively, and the silicone plate was removed 1 month
postoperatively.