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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5805_Библиотеки_им_академика_М_И_Перельмана.pdf
136
11 Isolated Cleft ofSecondary Palate
a
NB
ML
0.58 cm
d
Fig. 11.5 3D illustration in isolated CP at 14 weeks
(TVS) (a) midsagittal section illustrating intact maxillary
line (ML). (b) Parasagittal section depicts the absence of
maxillary line (arrow) caudal to premaxilla (PM). (c)
Rendered view of face depicting retrognathia. (d) Intact
base (arrow) of RNT (e) Posterior coronal section illus-
b
e
c
PM
f
V
trating defect (arrows) in base of RNT. (f) Rendered axial
view of palate shows intact alveolar arch (arrowheads)
and note that the echogenic plate of bone caudal to the
alveolar arch is decient, hence the vomer (V) is seen in
midline, Nasal bone (NB)
corresponding sagittal section shows shortening
of the maxillary line in the parasagittal section,
and the defect is evident in posterior coronal
sections.
Figure 11.9a is a rendered image of the normal
palate using the omni view technique, and
Fig.11.9b and c is a rendered image of an isolated cleft of the secondary palate in two different
cases.
Figure 11.10 is the rendered view of the palate
using the ipped face technique (see Chap. 6,
Fig. 6.7). Various rendering modes can be used,
such as the surface rendering mode or the HD
live mode. In Fig.11.10a the vomer is not visualized in midline due to the presence of secondary
palate, whereas in Fig. 11.10b, note that the
vomer is seen in midline indicating cleft of the
secondary palate.
Either multiplanar imaging or the omni view
technique or the rendered view of the palate by
ipped face technique can demonstrate clearly
the absence of echogenic plate of bone caudal to
the alveolar arch, and the vomer bone can be
seen in midline through the defect in the secondary palate. Figure11.11 shows the rendered
view of the intraoral surface of the palate in three
cases of isolated CP.
Figure 11.12 is a case of isolated CP in which
the 2D markers are very subtle. The clue is the
absent superimposed line sign in the midsagittal
section during the routine transabdominal scan
(Fig.11.12a).
However, the transvaginal scan demonstrates
the maxillary gap (Fig.11.12b). Rendered view
of the face shows the intact upper lip (Fig.11.12c)
and multiplanar and omni view technique conrms the cleft of the secondary palate (Fig.11.12
d, e).
The appearance of the midline septum (i.e.)
vomer varies in size and form in isolated cleft
palate compared with bilateral CLP. Though in
both types, the vomer is seen as a midline structure, in bilateral CLP, the inferior border of the
vomer is thick and rounded, whereas in the iso-
11.2 Diagnostic Approach withSonographic Signs inFirst Trimester
137
a
ML
b
P
PM
P
M
ML ML
Fig. 11.6 TUI in isolated CP vs. normal palate in the sagittal section at 14weeks (a) midsagittal section (M) shows
the vomer as maxillary line (ML). White dashed line,
parasagittal section (P) shows the absence of the posterior
ML
P
aspect of the maxillary line (arrow) in isolated CP. (b)
midsagittal section and parasagittal section illustrates the
intact maxillary line
138
11 Isolated Cleft ofSecondary Palate
a
b
Fig. 11.7 Comparison of TUI in isolated CP with the
normal palate in the coronal section at 14 weeks (a) In
isolated CP anterior coronal section shows intact base
(arrowhead) of retronasal triangle whereas the posterior
sections show defect (arrows) in the base. (b) In case of
normal palate intact base of triangle is seen in both anterior and posterior coronal sections (arrow)
11.2 Diagnostic Approach withSonographic Signs inFirst Trimester
a
ML
139
V
b
V
Fig. 11.8 Multiplanar imaging in isolated CP at 14weeks
(TVS) (a) The reference dot (yellow dot) is placed at the
tip of the maxillary line (ML) in the sagittal section, the
corresponding axial view shows intact alveolar arch and a
normal nose chin view, vomer (V). (b) multiplanar imaging with reference dot (yellow dot) placed in the defect.
(Note complete absence (arrows) of the base of the triangle in coronal section)
140
11 Isolated Cleft ofSecondary Palate
a
P
b
Fig. 11.9 Omni view technique in normal and isolated
CP at 14weeks (a) Illustration of the normal palate (P),
note the intact alveolar arch and the echogenic plate of
V
bone is clearly visible. (b) Case 1and (c) Case 2: note that
in isolated CP the vomer (v) of the nasal cavity is imaged
in midline as the secondary palate is decient
11.4 Diagnostic Approach withSonographic Signs inMid Trimester
c
Fig. 11.9 (continued)
141
V
lated cleft palate, the vomer is thin and
knife-edged.
The vomer in the isolated cleft of secondary
palate is illustrated in Fig.11.13a, and the appearance of the vomer in bilateral CLP is shown in
Fig.11.13b. Note that the vomer in isolated CP is
thin, and the thickness of the vomer in bilateral
CLP is increased [6].
11.3 Pitfalls inFirst Trimester
The potential pitfall in utilizing the axial view
alone is if a section is taken in 2D or in 3D cranial
to the actual plane of the palate inadvertently
passing through the nasal cavity, then there can
be a potential false diagnosis. This can be minimized by visualizing the most caudal arch, i.e.,
mandibular arch in axial sweep and then just
moving a little superior to visualize the maxillary
arch.
In 3D imaging, while rendering the palate in
ipped face view, care should be taken to place
the green line of the render box on the surface of
visualized maxillary line in the oral cavity, as
shown in Fig.11.14a. The green line of the ren-
der box should not be placed on the side of the
nasal cavity as shown in Fig.11.14b. The vomer
is now seen in the midline and should not be mistaken for cleft of secondary palate [7].
11.4 Diagnostic Approach
withSonographic Signs
inMid Trimester
In mid trimester the diagnosis of the isolated
cleft of the secondary palate relies on imaging
the uvula. The typical equal sign to image the
uvula as described by Wilhelm is well seen in
mid trimester from 20weeks of gestation [1].
However, imaging the bony hard palate and
the soft palate can be attempted from 14weeks of
gestation. Imaging the secondary palate from 13
to 22 weeks of gestation is illustrated in
Fig. 11.15. The soft palate lies at an angle of
about 30 degrees to the bony secondary palate
(Fig.11.15d).
The secondary palate gradually increases in
curvature, and the uvula lengthens with
advancement of gestation. Though the uvula is
not seen in late rst trimester the soft palate can
142
11 Isolated Cleft ofSecondary Palate
a
P
b
Fig. 11.10 Flipped face technique using HD live mode
in normal and isolated CP (a) Rendered image of the normal palate (P). (b) Rendered image of isolated posterior
*
cleft of secondary palate. Note that the vomer (*) of the
nasal cavity is visible in midline
11.4 Diagnostic Approach withSonographic Signs inMid Trimester
143
a
*
c
b
*
*
Fig. 11.11 Rendered intraoral surface of palate in isolated CP.(a) case 1 (b) case 2 (c) case 3. Note the midline echo
of nasal septum (*) in all the three cases
be imaged separating the oral cavity from the
nasal cavity as early as 13 to 14weeks of gestation (Fig.11.15a, b).
According to Wilhelm, the uvula could be
visualized with a typical echo pattern in about
90% of the cases, and the soft palate could be
completely visualized in a midsagittal section in
85% of the cases. They also quoted that in 98.4%
of the cases, visualization of either the uvula or
the soft palate was successful.
The uvula is illustrated in the median sagittal
section in Fig. 11.16a, b at 19 weeks and
22weeks, respectively. The uvula can be visualized in the corresponding transverse axial section
at the base of the skull at the level of the oropharynx (Fig.11.16a1, b1).
The uvula can also be imaged in the frontal
section, as shown in Fig.11.17a (Video 11.1). In
case of cleft in secondary palate, the typical
equal sign of the uvula cannot be imaged as
shown in Fig.11.17b (Video 11.2). A new tech-
nique of visualizing the uvula with HD live has
also been proposed recently [8].
Figure 11.18a shows the normal appearance
of the intact palate at 22weeks of gestation, and
Fig.11.18b is a cleft of the secondary palate. The
soft palate is continuous with the bony hard palate and forms a muscular curtain separating the
oropharynx and nasopharynx (Fig. 11.18a). In
cleft of secondary palate the soft palate is not
visualized, and the midline echogenic line ends
abruptly as shown in Fig.11.18b.
Two case scenarios of isolated cleft palate
diagnosed at 13 weeks and followed up in mid
trimester are shown below. In case: 1, the lead
clue was the presence of maxillary gap and
144
11 Isolated Cleft ofSecondary Palate
a
ML
d
Fig. 11.12 2D Vs 3D correlation in isolated CP at
12 weeks. (a) (TAS) 2D midsagittal image showing a
single line at the posterior aspect of maxillary line (ML)
(b) (TVS) 2D midsagittal image demonstrating maxillary
V
b
c
e
V
gap (arrow) (c) TVS Rendered view of face (d) and (e)
(TVS) multiplanar imaging and omni view showing a
defect in secondary palate, note that the vomer (V) is visualized in midline
absent superimposed line sign. Also, the parasagittal sections showed shortening of the maxillary line (see Fig.11.1b).
Case: 2 is an example of the posterior cleft of
the secondary palate wherein only the absent
superimposed line sign serves as the lead clue
(see Fig.11.1c).
Figure 11.19 is a case of isolated CP suspected
at 13 weeks and followed up at 18 weeks. The
sagittal section (11.19a) shows a subtle maxillary
gap and absent superimposed line sign, but however, the sagittal section slightly off the midline
shows the absence of the maxillary line (11.19b).
This case was followed up at 18weeks, the midsagittal section shows an abrupt ending echogenic line, and the uvula could not be seen
(11.19c).
The sagittal section demonstrates that the
maxillary line is absent (11.19d). Note that the
abrupt ending echogenic line in the midline is
actually the vomer of the nasal cavity and not
the secondary palate.
Figure 11.20 is an illustration of Pierre Robin
syndrome associated with the posterior cleft of
the secondary palate. The maxillary gap is not
evident in midsagittal section, and there is only
a single line seen at the posterior aspect of the
maxillary line (Fig.11.20a).
Figure 11.20b illustrates the intact base of the
retronasal triangle and the absent mandibular gap
sign indicating associated micrognathia in a case
of Pierre Robin sequence. Figure 11.20c conrms the 2D ndings. The reference dot placed
posterior to the premaxilla shows a decient palate in the coronal section.
TUI depicts the intact base of the triangle in
the anterior coronal section and the decient base
in the posterior coronal section (Fig. 11.20d).
Follow-up scan at 16weeks clearly shows that
the posterior part of the secondary palate is decient in the midsagittal section in Fig.11.20e and
f. (Video 11.3).
Utility of superimposed line sign in the diagnosis of the posterior cleft of secondary palate is
11.5 Pitfalls inMid Trimester
145
a
a1
ML
b
ML
b1
V
V
Fig. 11.13 Appearance of vomer in isolated CP and
bilateral CLP (a) In isolated CP, note that the vomer
(arrow) is seen as a sharp thin line. (a1) Corresponding
axial rendered view illustrating the same, Vomer (V). (b
illustrated in Fig.11.21. In cleft of the secondary
palate as the posterior portion of the palate is
decient, (highlighted in yellow) only a single
line is seen which is the vomer (Fig.11.21a, b).
The superimposed line sign is shown in
Fig.11.21c, wherein the posterior aspect of the
maxillary line appears bid (Video 11.4).
Figure 11.22 illustrates the follow-up of the
same case at 16weeks. The receding chin along
with the absent superimposed line sign, is evident
in the midsagittal prole (Fig. 11.22a).
Figure11.22b shows the abnormally placed retro
positioned tongue suspicious of glossoptosis.
and b1) In bilateral CLP, note that the vomer is thick and
rounded. Arrow points to the posterior aspect of the maxillary line (ML) which is the vomer
Figure 11.22c illustrates the rendering of the
U-shaped mandible seen in PRS, and Fig.11.22d
illustrates rendered view of the palate. Note that
the palate is decient in the posterior aspect, and
the vomer is imaged in the midline.
11.5 Pitfalls inMid Trimester
As the palate is dome shaped and arched in the
mid trimester the palate cannot be entirely visualized by 2D ultrasound in a single plane. Moreover,
shadowing caused by the premaxilla and facial