Key-words:
Endoscope - intraventricular - thalamic
Introduction
Basic endoscopic skills have already been discussed previous three papers on putaminal,
subcortical, and cerebellar hemorrhage. Thalamic hemorrhage is deep, so it is very
invasive to approach by craniotomy. The authors have experience of about 50 cases
of endoscopic evacuation of the thalamic hematoma through intraventricular route.
Once we introduce the lucent sheath in the hematoma cavity, the process is same like
another hematoma evacuation. We can control intracranial pressure and hydrocephalus
by evacuating hematoma from the 3rd ventricle and can wait for sometime without intervention.
Before Operation
Indication
All kinds of intraventricular hemorrhage (IVH) and thalamic hemorrhage (TH) can be
evacuated through the endoscope. If there is very small thalamic hematoma or hematoma
on one side only, may not be operated. External ventricular drainage (EVD) should
be placed in case of worsening of the hydrocephalus in these cases.
Preoperative examination
Magnetic resonance angiography or computed tomography angiography (CTA) should be
done. The authors prefer digital subtraction angiography to CTA as this can exclude
arteriovenous malformation (AVM), arteriovenous fistula (AVF), moyamoya, aneurysmal
hemorrhage, high or low flow AVM/AVF, and venous angiomas. Venous malformations are
contraindication for surgery. It is difficult to coagulate bleeding from big vessel.
Marking on the skull for entry point should be done with CT scan (axial, coronal,
and sagittal image). MRI T2 STIR image can show the bleeding point.
Instrumentation
We need both the rigid and flexible endoscope along with the translucent sheath of
both the large and smaller diameter. Bigger one needed in case of expected bleeding
or to coagulate the larger vessel. It is better if we have a suction tube with irrigation.
Otherwise, we can use angiographic sheath or catheter for irrigation which can be
placed in the suction or endoscope. We need a special tool for hemostasis in case
of using flexible endoscope [[Figure 1]].
Figure 1: Instruments for intraventricular hemorrhage
Approach
We need to investigate the position, extension, and wideness of the hematoma. There
can be three approaches for the hematoma evacuation from thalamic and intraventricular
bleed.
-
Anterior horn
-
Posterior horn
-
Direct puncture to the hematoma
In some cases, we can combine all three of them:
-
Anterior horn puncture – This approach is used for IVH in the lateral horns, body,
and 3rd ventricular hematoma. This approach is not used for hematoma in the posterior
horn. This can also be used in ventricular hemorrhage with TH in medial upper direction.
In this approach, TH can be evacuated after evacuating the intraventricular part.
Sheath is advanced in the thalamic hematoma after evacuating the ventricular part
-
Posterior horn puncture – This is better approach for thalamic hematoma which extends
to posterior horn and brainstem in posteroinferior direction. We need navigation system
or CT-guided system for the evacuation as there is no landmark for orientation as
in case of anterior horn approach
-
Direct puncture – If the hemorrhage is in the anterolateral direction close to the
putaminal/temporal region, we can use the direct puncture as in case of putaminal
or subcortical hemorrhage [[Figure 2]].
Figure 2: Localization and approach to the hematoma
Anesthesia and Positioning
The authors prefer to evacuate under general anesthesia as it may take longer time
to evacuate the hematoma. Position is decided by the approach and wideness of the
hematoma [[Figure 3]].
Figure 3: Approach and position
Approach: Evacuation of Thalamic Hematoma
For puncture through the anterior horn, translucent sheath is inserted and flexible
endoscope is introduced. Anatomical landmarks, for example, foramen of monro and choroid
plexus confirmed. When sheath is placed in hematoma cavity, we change from flexible
to rigid endoscope. Hematoma cavity is observed with the help of irrigation and suction.
In case of puncture through the posterior horn, it is better to use navigation system
or CT-guided system to decide the puncture point. Once sheath is inserted in the hematoma
cavity, irrigation is stopped and evacuation of the thalamic hematoma is started.
In thalamic hematoma, we push the sheath lightly in the hematoma, and it is evacuated
inside out because if CSF start coming in the sheath, initially, it is difficult to
perform the procedure. If the thalamic hematoma is removed directly, it is removed
in the same way as described before, inside-to-outside technique [[Figure 4]].
Figure 4: Hematoma removal
Technique
There can be four-hand technique which is commonly practiced in which surgeon holds
rigid scope with the right hand and keep irrigation suction in the left hand. Assistant
holds the sheath and helps with irrigation and coagulation. In two-hand technique,
surgeon holds scope in the right hand and irrigation, suction, and sheath with the
left hand. Although the two-hand technique is faster, it needs much more expertise
[[[Figure 5]] and Video].
Figure 5: Hematoma removal using Flexible Endoscope
Evacuation of intraventricular hemorrhage
In case of IVH, when we use rigid endoscope, we can suction out all the hematomas
very fast. Due to this sudden collapse of ventricle some time brain shrinks and can
cause acute subdural hematoma. The authors advocate the use of flexible endoscope
for the evacuation of IVH. We can do slow evacuation and continuous irrigation with
the flexible endoscope and keep the ventricle expanded to avoid sudden collapse and
its complications. In flexible endoscope, we remove hematoma from the hole in the
endoscope. We must know the position of hole so that we can suction with one hole
and use other instruments, for example, monopolar and forceps with another hole. We
put the hole toward the hematoma and suction with 5-10 ml syringe. When the hematoma
amount is large, it can block the suction. If the endoscope gets blocked, hematoma
is flushed off outside the brain. This procedure is repeated several times until the
ventricles get cleared. If the aqueduct is dilated, we can negotiate flexible endoscope
in the 4th ventricle for evacuation of hematoma, but the authors do not recommend
this due to high risk. To prevent the hydrocephalus, we either can do the 3rd ventriculostomy
or EVD can be left after the operation. Sheathless technique can also be used if there
is a route for the egress of the fluid; bilateral EVD or one side EVD has been done
and we proceed from the other side. Scope can be moved more freely without the sheath,
but we should be careful for the vital structure around the ventricle. Endoscope is
negotiated by irrigation and pushing technique into the ventricle in sheathless procedure.
This procedure is not recommended as standard, but sometimes, it is very effective
and better to know this technique [[Figure 6]].
Figure 6: Removal through flexible endoscope sheath/sheathless
Checking hemostasis
There are small perforators in thalamic bleed so hemostasis can be easily achieved.
Monopolar is used for coagulation like in other bleeding. In IVH, new bleeding is
unlikely to occur unless we injure the ventricular structure. We should take care
of the veins on the ventricular wall, bleeding from the choroid plexus, tract, and
the puncture point. Mostly bleeding is stopped with water pressure by taking endoscope
close to the bleeding point. Vital tissue can be damaged if we use coagulation tool.
Bleeding should be stopped, every time we find them. If there is large intraventricular
bleeding, it must be stopped by irrigation, pressure, or drainage. New bleeding hematoma
is sometimes hard to evacuate. It needs bigger sheath and suction tube and may need
to change from flexible to rigid endoscope. If there is small hematoma on the bleeding
point, it should not be pulled out.
Closure
If the 3rd ventricle is clear, no hematoma in aqueduct and 3rd ventriculostomy has
been done, and then, there is no need for the ventricular drainage. After the endoscopic
procedure, tract is bigger than the normal drainage, so there may be postoperative
subdural hygroma or CSF leak. The authors use hemostatic material, for example, fibrin
glue for the closure of the tract, dural closure with suture, and application of fibrin
glue on the suture line. The authors prefer to close the burr hole with ceramic cap.
Skin and muscles are closed like normal durotomy.
Conclusion
We can remove the hematoma less invasively with neuroendoscope, and we can get good
result in cases of thalamic hematoma with IVH.
