Figure legends
Figure 1. Brain images at the first examination
A. Brain computed tomography (CT) with 4-mm slice thickness showing
fluid accumulation with air inclusion in the right sphenoid sinus. No
fistula is detected.
B. Fluid-attenuated inversion recovery magnetic resonance image (MRI)
showing no evidence of deviation of the cranial contents into the
sphenoid sinus.
Figure 2. Comparison of pre- and postoperative CT images
A. Preoperative high-resolution (HR) CT images: A1, axial section; A2,
coronal section; A3, sagittal section. The yellow arrowheads point to
the fistula.
B. Postoperative HRCT images: A1, axial section; A2, coronal section;
A3, sagittal section. The yellow arrowheads point to the fistula. The
fistula is filled with bone pile.
Figure 3. Comparison of pre- and postoperative endoscopic findings
A. Preoperative endoscopic finding. Transparent serous fluid is observed
to be flowing from the natural ostium of the right sphenoid sinus in the
direction of the right choana.
B. Postoperative endoscopic finding. The anterior wall of the sphenoid
sinus is removed. The bottom and lateral wall of the sphenoid sinus is
covered by the nasoseptal mucosal flap.
Abbreviations: C, choana; ltSS, left sphenoid sinus; NS, nasal septum;
NSF, nasoseptal mucosal flap; rtSS, right sphenoid sinus.
Figure 4. Intraoperative endoscopic findings accompanying the surgical
procedure.
The black arrowheads point to the fistula.
A. Right endoscopic sinus surgery is performed.
B. The fistula covered with the mucosa is identified at the lateral wall
of the right sphenoid sinus with a 70-degree telescope.
C. The fistula is further revealed after removal of a part of the mucosa
and the CSF leak is confirmed with a 70-degree telescope.
D. The left nasal septum mucosa is incised and elevated for the
transseptal approach.
E. The sphenoid crest is identified at the posterior end of the nasal
septum.
F. A rescue incision is made to the natural ostium of the right sphenoid
sinus, parallel to the nasal floor.
G. The sphenoid crest is removed to expand the surgical field.
F. The surgical field is expanded laterally by removing the anterior
wall of the sphenoid sinus.
Abbreviations: LP, lamina papyracea; ltNSM, left nasal septum mucosa;
ltSS, left sphenoid sinus; MT, middle turbinate; rtSS, right sphenoid
sinus; SC, sphenoid crest
Figure 5. Intraoperative endoscopic findings accompanying the surgical
procedure
The black arrowheads indicate the fistulas. E and H are findings with
the 0-degree telescope, and the remaining are findings with the
30-degree telescope.
A. The arachnoid mater is identified in the fistula.
B,C,D. A collagen matrix is inserted into the fistula.
E. The bone is formed into a pile according to the size of the fistula.
F,G. The bone is inserted into the fistula in a pile-driving manner.
H. The lateral wall of the sphenoid sinus is covered with a nasoseptal
mucosal flap.
Abbreviation: ltSS, left sphenoid sinus; NSF, nasoseptal mucosal flap