Endoscopic Third ventriculostomy procedure

Endoscopic Third ventriculostomy procedure, a minimally invasive surgery done using a neuro endoscopy procedure for visualization and bypass Cerebrospinal fluid (CSF) through the third ventricle of the brain.

Indication 

Hydrocephalus due to obstruction

Pathological condition

Intraventricular cyst

Neurocysticercosis

Cyst or Tumours causes Hydrocephalus

Position 

Make sure all the imaging facility and detailed notes of procedure written on the notice board of the Operating room

The patient placed in a supine position with a slight head flexed according to the site of the incision. Precoronal frontal burr hole 3 cm lateral to the midline.

Endoscopic ventriculostomy: Instrument used 

1. Complete Endoscopy Console
2. Camera
3. Light cable
4. Irrigation system [warm RL Solution]
5. Endoscope holder or Leyla arms (two) attached to the table
6. Trocar and sheath
7. O Ventriculoscope
8. Operative endoscope
9. Bipolar endo-surgical unit with the appropriate accessory 
10. Fogarty balloon catheter
11. Biopsy forceps
12. Endoscopic scissor

Craniotomy: Burr hole

1. #20 with BP handle blade for skin incision
2. #15 blade for dura mater
3. Tissue holding forceps
4. Drill (Electric or Pneumatic) or Hudson brace for Burr hole
5. Periosteal elevator
6. Irrigation syringe with saline
7. Dural Scissor
8. Bayonet forceps

Before they start painting the patients with the disinfection solution. Surgical site cleaning and drape the patient exposing the surgical site. Mark the incision site on the head, and create a flap on the incision site.

Note: In some cases Stereotactic method used for accuracy.  (Neuro navigation assisted)

For holding the endoscope using the endoscopic holder or Leyla retracting system. The surgeon may choose the flexible endoscopic holding system for the usage, according to their concern

After opening the skull with Hudson brace burr or electric Drill/Pneumatic drill, open the dura mater with the #11 blade.

In some of the cases, the surgeon and anaesthesiologist check the intracranial pressure.

ETV endoscopic third ventriculostomy procedure

After the insertion of the brain cannula connected to the ICP transducer, ICP monitored and documented for future reference.

Insert the brain cannula for the CSF drainage and collect CSF for analysis and then insert the trocar with a sheath to enter the ventricle. Remove trocar and insert 0⁰Endoscope for visualization of the ventricle. Connect to the irrigation system (Warm Ringer lactate solution).

Connect the irrigation port to the endoscopic sheath for better visualization inside the brain 

structure.

Insert operating endoscope and fix it to the sheath.

Enter the third ventricle through the foramen of Monro and fix the endoscope above the floor of the third ventricle.

In the third ventricle, mammillary bodies are identified as two white bulges and infundibular recess a

s orange structure. In between infundibulum and mammillary bodies the dorsum sell is seen as a white band like structure through the floor of the third ventricle.  The basilar artery is seen through the floor between dorsum sellae and mammillary bodies. The floor of the third ventricle is perforated with forceps or bipolar electrodes without using energy between the dorsum sellae and basilar artery. The perforation is enlarged by the inflating Fogarty balloon (3F). The balloon using a Ringer lactate solution or air.

Inspection of the prepontine area to visualize the basilar artery in subarachnoid space. After continuous Ringer lactate saline irrigation to control hemostasis confirm that there is no damage to the foramen of Monro and withdraw the scope

Biopsy procedure

For the biopsy procedure, rotate the endoscope to 1800 Ventriculoscope for better visualization and to access the tumor in the posterior third ventricle. Biopsy sample store in the sample table with normal saline. Control hemostasis after biopsy, using Ringer lactate irrigation. If hemostasis not controlled, use a Bipolar endo-surgical unit or Fogarty catheter inflation inside the tumor.

Closure

#3-O Vicryl suture for galea

2-O Silk suture for skin closure

Needle holder

Thumb forceps

Anatomy of ventricle

Ventricles of the brain- a total of 4 ventricle

2 lateral ventricle (Right and left)

Third ventricle and fourth ventricle

Ventricles present in both sides of the cerebral hemisphere which communicates with each other. C-shaped lateral ventricles with frontal horn anterior

Posterior -Body, Atrium, Occipital horn

Inferior- Temporal horn

Ventricles with Fluid called CSF-Cerebro spinal fluid which secretes from choroid plexus.

 

Post reviewed and edited by Dr.Dhaval Shukla  Professor of Neurosurgery, NIMHANS, Bangalore.

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