Neurosurgery notes/Procedures/Cranial procedures/CSF procedures/ETV

ETV

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CSF procedures

Anatomy

  • Infundibulum
  • Septal vein
  • Thalmostrioate vein
notion image
 
notion image
Need to look for membrane after the floor of the 3rd ventricle is open. If membrane is present then need to open them. must be able to see the cranial nerves

Treatment choice guided by classification

Physiological classification most important
  • Communicating vs obstructive
  • Aetiology
Treatment choice guided by classification • Physiological classification most important — Communicating vs obstructive — Aetiology
 

ETV vs VPS

  • Enthusiast's view: "ETV (+/- CPC) offer "lifelong shunt freedom"
  • Cynics view: "an operation that's fun against an operation that works"
  • Balanced view: "ETV offers short-term pain for long term gain (and sometimes doesn't work)"
      • VP shunt is usually most appropriate for communicating hydrocephalus
      • ETV should be considered first for hydrocephalus due to congenital aqueduct stenosis
      • Late ETV failure (2 years) is less common than late VP shunt failure
      • Majority of ETV failure occurs in the first 3 months
      International Infant Hydrocephalus Study (IIHS) 1-0 SHUNT 0.8 0.6 0.4 02 0.0 Years after procedure FW 2 Kapun-Meia suvival canes One-to-fimt ETV md shÄ
      International Infant Hydrocephalus Study (IIHS). Unadjusted Kaplan-Meier survivor curves comparing time-to-first treatment failure for ETV and shunt for the entire cohort.
  • Aside from obstructive hydrocephalus in children older than 2 years and adults, in whom ETV is often used, VPS placement remains the standard of care.
  • Evidence
    • IIHS and CURE showed no difference in QOL, treatment failure between ETV vs VPS for children with aqueductal stenosis or post infection HCP

Procedure

  • Procedure involves passing an endoscope into the frontal horn of the lateral ventricle, through the foramen of Monro, and into the third ventricle.
  • Opening made in the floor of the third ventricle to establish direct communication with the prepontine cistern.
  • Simultaneous choroid plexus cauterization (CPC)
    • Done in very young patients:
    • Aims to enhance ETV efficacy.
    • Better results seen in children younger than 1 year, with efficacy proportional to the amount of choroid plexus cauterized.
  • ETV success score: Kulkarni 2010
    • Calculation of the ETVSS*
        • Score
        Age
        Etiology
        Previous Shunt
        0
        <1 mo
        Postinfectious
        Yes
        10
        1 mo to <6 mos
        ㅤ
        No
        20
        ㅤ
        Myelomeningocele, IVH, nontectal brain tumor
        ㅤ
        30
        6 mos to <1 yr
        Aqueductal stenosis, tectal tumor, other
        ㅤ
        40
        1 yr to <10 yrs
        ㅤ
        ㅤ
        50
        ≥10 yrs
        ㅤ
        ㅤ
      • * The ETVSS is calculated as Age Score + Etiology Score + Previous Shunt Score. Abbreviation: IVH = intraventricular hemorrhage.
    • Temporal pattern of ETV failure:
      • The risk of ETV failure becomes progressively lower compared with the risk of shunt failure with increasing time from the surgery.
      • In the best ETV candidates (ETVSS ≥ 80),
        • The risk of ETV failure is lower than the risk of shunt failure very soon after surgery,
      • Less-than-ideal ETV candidates (ETVSS ≤ 70)
        • The risk of ETV failure is initially higher than the risk of shunt failure and only becomes lower after 3–6 months from surgery.
      • Higher risk of early ETV failure within the first 3 months;
        • Lower risk of delayed ETV failure compared to delayed shunt failure.
      • Late ETV failures are rare but potentially fatal.
  • Complications of ETV:
    • Basilar artery injury (0.2%)
    • Permanent endocrinopathy (0.9%)
    • Hypothalamic injury or other brain injury (0.2%)
    • Perioperative mortality (0.2%).
    • Fornices injury
      • Causing
        • Transient memory loss
        • Personality disorders
  • Intraoperative considerations:
    • Bradycardia during third ventricular floor perforation
      • Due to elevated ICP from aggressive irrigation and preoptic area stimulation → Cushing’s response
    • Posterior hypothalamus stimulation may lead to tachycardia.