Brainstem safe surgical approach associated microanatomy

Alis Guberinic of the Department of Neurosurgery at Nijmegen University Medical Center in the Netherlands and others described in detail the relevant microdissection of the brainstem safe entry area by PLI combined with 11.

——Excerpt from the article chapter

【Ref: Guberinic A, et al.

Research background

It was previously thought that the brainstem was a no-go area for

Results of the study

The authors provide an overview of the microanatomical and surgical approach safety of the 13 brainstem safety zones proposed by Professor Spetzler, including the anterior midbrain region, the lateral midbrain sulcus, the intercerebral region, the interthalamic region, the superior trigeminal nerve area, the peritrigeminal nerve area, the lateral pontineal region, the midbrain sulcus, the subthalamus, the suprathalamus, the olive region, the lateral medulla oblongation region and the anterolateral sulcus (Figures 1-7).

Midbrain:

Pre-midbrain region: transorbital zygomatic, subtemporal, and pre-rock bone access to the anterior midbrain region (AMZ), transanterior midbrain region can be resected ventral lesions; The corticospinal tract is mainly located in the outer two-thirds of the cerebral foot, the inner third of the cerebral foot is sparsely fiber, and the oculomotor nerve can locate the substantia nigra

Inter-foot area: the interfoot area (IPZ) can be reached by the orbital zygomatic approach, and the ventral lesion

Lateral midbrain sulcus: transient subcaperial (SCIT) approach, extreme lateral SCIT approach, posterior sigmoid sinus approach, and postlabyrinth approach to the lateral midbrain sulcus (LMS), and lateral midbrain ventral or dorsolateral lesions

Interthalamic region: the interthalamic region (ICR) can be reached by the supramyelago (SCIT) and very lateral SCIT approaches, and the dorsal midbrain lesion

Upper trigeminal nerve area: transtemporal subtemporal canopy access, anterior rock bone resection, posterior sigmoid sinus approach and post-labyrinth approach can reach the superior trigeminal nerve region (STZ), and the lesion
of the upper part of the pontine brain can be removed via the superior trigeminal nerve area.

Peritrigeminal region: peritrigeminal region (PTZ) is reached by the anterior approach to the rock bone, the posterior sigmoid sinus approach, and the post-labyrinth approach can be reached and the peritrigeminal lesion
can be removed by PTZ.

Lateral pontine region: the lateral pontine region (LPZ) can be reached by the posterior and labyrinth approaches via the sigmoid sinus, and the lesion under the trigeminal nerve can be removed through the lateral region of the
pontifoli.

Mesozomes: the mid-groove (MS) can be reached by the suboccipital midplane sail approach, and the lesions
behind the brainstem can be removed through the mid-groove.

Upper surface mound: The upper surface mounds (SCZ) can be reached by the suboccipital mid-membrane sail approach, and the lesions
located above the migratory mounds can be removed through the upper surface mounds.

Sub-facial mound: The sub-facial area (ICZ) can be reached by the suboccipital mid-membrane sail approach, and the lesions
located above the facial mound can be removed through the sub-facial mound.

Medulla oblongata:

Olive area: the olive area (OZ) can be reached by the distal lateral approach and after the labyrinth, and the ventral lesion
of the medulla oblonga can be removed through the olive area.

The cortical spinal tract and sublingual nerves are closely
related to the olive nucleus.

Lateral medulla oblongata: the lateral region of the medulla oblongata can be reached by the posterior sigmoid sinus approach, the distal lateral approach, and the post-labyrinth approach to the lateral region of the medulla oblongation can be removed by the lateral region of the medulla oblongata, and the lateral region of the medulla oblongata is bounded
by vagus and glossopharyngeal nerves.

Anterolateral sulcus: posterior sigmoid sinus approach, distal lateral approach, and labyrinth approach to reach the anterolateral sulcus (ALS), excision via anterolateral sulcus to remove lesions located on the lateral ventral of the medulla oblongata, with the anterolateral sulcus bounded
by the corticospinal tract.

Figure 1.
Surgical approach and exposed anatomical structures in the safe entry area
.

A.
The cross-sectional of the base of the skull shows that each color represents the surgical approach
to a safe entry area.

B.
Anterioraxial view
of the brainstem.

Red is the anatomy exposed by the orbital zygomatic approach to the brainstem, and purple is the anatomy
exposed by the labyrinth approach.

C.
Lateral view of
the brainstem.

Blue is the anatomy exposed by the transtemporal approach and blue-green is the anatomy exposed by the enlarged subtemporal approach combined with pre-rock bone resection
.

D.
Lateral view
of the posterior midbrain.

Pink is the (pole) lateral SCIT approach exposed anatomy
.

E.
Posterior midbrain view
.

Brown shows the anatomical dissection
exposed by the middle SCIT approach.

F.
Lateral view
of the brainstem.

Dark green indicates the anatomy exposed by the posterior approach of the sigmoid sinus
.

G.
Posterolateral view
of the brainstem.

Yellow indicates the anatomy exposed by the distal lateral approach
.

H.
Posterior view of
the brainstem.

The light green color is the anatomy,
which is exposed by the suboccipital midstream sail entry.

Figure 2.
Brainstem 11.
7T MRI axisymmetric imaging
.

1: Brainstem ventral view
.

A.
Axial slices of the upper part of the midbrain
.

B.
Axial slices of the lower midbrain
.

C.
Axial slices of the upper pontineal brain
.

D.
Axial section of trigeminal nerve root entry into the pontine level
.

E.
Axial slices of the lower pontine brain
.

F.
Axial slice of the horizontal medulla oblongata of the lower olive nucleus
.

Figure 3.
Axial facet
of the midbrain.

A.
Ventral view
of the brainstem.

B.
Pattern diagram of the PLI image shown in Figure
C.

C.
Axisymmetric view of PLI images in the upper part of the midbrain
.

D.
Pattern diagram of the PLI image shown in Figure
E.

E.
Axisymmetric view of PLI images in the lower midbrain
.

Figure 5.
Axial slices of the pons
.

A.
Lateral view of
the brainstem.

B.
Axisymmetric view
of PLI images in the upper pontine brain.

C.
Pattern diagram of the PLI image shown in Figure
B.

D.
Axis-oriented view
of trigeminal nerve root entering the pont-brain PLI image.

E.
Schematic diagram of the PLI image shown in Figure
D.

F.
Axial view
of PLI images in the lower part of the pons.

G.
Schematic diagram of the PLI image shown in Figure
F.

Figure 6.
The trigeminal nerve root enters the sagittal position at the pontine level
.

A.
Lateral view
of the brainstem.

B.
Coronal view
of PLI image of trigeminal nerve root entry zone.

C.
Pattern diagram of the PLI image shown in Figure
B.

Figure 7.
Axial slice of medulla oblongata
.

A.
Anteriorlateral view
of the brainstem.

B.
PLI image of the lower olive-like horizontal medullabilia
.

C.
PLI image
of the horizontal medulla oblongata located between the olive kernel and the C1 root.

D.
Pattern diagram of the PLI image shown in Figure
B.

E.
Pattern diagram of the PLI image shown in Figure
C.

Conclusion of the study

Finally, the authors note that microanatomical studies of PLI combined with 11.
7T MRI imaging help neurosurgeons grasp the internal structure of the human brainstem and thus establish a safe surgical approach to handling intrabrainstem lesions
.