Hydrocephalus and Neuro Shunting

Sales Training

April 2001

Hydrocephalus :

From the Greek word hydro (water) & cephalo (head).

A pathological condition where there is a disturbance in production, circulation and/or absorption of CSF, with subsequent accumulation of CSF in the fluid-filled compartments of the brain (ventricles).

About CSF

(Cerebrospinal Fluid)

    Clear, colorless fluid Bathes, nourishes & protects brain and spinal cord.

Average CSF production-20ml/hr adults and 8ml/hr children 400 to 500cc produced daily contains 15 to 45mg/100ml protein,some glucose, salts, urea and WBC’s

Ventricular System

Fluid filled cavities deep in cerebrum w/ pressure of 120 180mmH2O Four ventricles  2 Lateral  Third  Fourth Connected by  Foramen of Monro  Aqueduct of Sylvius

Choroid Plexus

 Very vascular   Found throughout but mostly in lateral Responsible for ICP waveform/ follows arterial pulse

Brain Layers/CSF Absorption

A.

A.G.

- Arachnoid - Arachnoid

B.

Granulation - Bone

C.A.

C.V.

- Cerebral Artery - Cerebral Vein

D.

F.C.

- Dura Mater - Falx Cerebri

P.M.

- Pia Mater

S.

- Skin

S.A.S.

- Sub-Arachnoid

S.D.S.

Space - Sub-Dural Space

S.S.S

. - Superior Sagittal Sinus

CSF Flow-path

 CSF flows in a caudal direction through the lateral, third and fourth ventricles   Exits through foramina of Luschka and Magendie into subarachnoid space around spinal cord and brain.

Absorption occurs through the arachnoid granulations into the venous system.

Types of Hydrocephalus

     Communicating Non-communicating or Obstructive Normal Pressure Hydrocephalus Congenital Acquired

Normal CT Scan CT Scan Showing severe hydrocephalus

Etiology of Hydrocephalus

Communicating

 Overproduction/underabsorption of CSF   Choroid Plexus Papilloma-overproduces CSF SAH    Infection Neoplasms affecting the meninges Trauma

Etiology of Hydrocephalus

Non-Communicating (Obstructive)

 Aqueductal Stenosis  Arnold-Chiari Malformation (Cerebellar tonsils protrude into Foramen Magnum)     Cysts Myelomeningocele IVH Tumors (particularly posterior fossa)

  

Normal Pressure Hydrocephalus

Usually present in elderly Ventricular dilation despite normal CSF pressure Triad of symptoms 1) dementia 2) gait disturbances (usually earliest) 3) urinary incontinence

Signs & Symptoms Associated with Hydrocephalus

Infants

 Increased head size  Bulging Fontanels        Separation of Cranial Sutures Prominent Scalp Veins Persistent Vomiting Lethargy or irritability “Setting Sun” eyes Seizures Delayed Development

S/S Associated with Hydrocephalus,

cont.

Toddlers

 Increased head size      Persistent vomiting Headache Lethargy or irritability “Setting Sun” eyes Blurred Vision   Seizures Delayed Development

Hydrocephalus

“SETTING SUN” EYES

S/S Associated with Hydrocephalus,

cont.

Older Children & Adults

 Persistent Vomiting  Headache**      Visual Problems Lethargy Behavior Changes Difficulty with schoolwork Seizures

Diagnosis

    Clinical Evaluation Ultrasound (Intrauterine & through Fontanels.

CT Scan MRI

Treatment Modalities

Surgical Procedures

   Remove obstruction (Blood Clots, Tumors) Endoscopic Third Ventriculostomy Septal Fenestrations (Endoscopic)   Cyst Fenestrations (Endoscopic) Shunt Insertion

Interventions for Hydrocephalus

If untreated:

*50-60% die of complications

If treated:

*40% normal intelligence *70% live beyond infancy

Questions???

Historical Treatment of Hydrocephalous

Hippocrates recognizes water accumulation in the brain.

1545

-Thomas Phaire-1st non-surgical treatment--Herbal plasters, head wraps

18th Century

--ventricular puncture--death from meningitis common

1800’s

Variety of materials used to “wick” CSF from ventricles to subarachnoid space (i.e., linen threads, glass wool, rubber tube)

1898

-first lumboperitoneal shunt

Historical Treatment of Hydrocephalous,

con’t

1922

-Dandy-third ventriculostomy through subfrontal approach

1923

-Mixter-1st endoscopic 3rd Vent., choroid plexectomy (L’Espinasse, Hildebrande, Dandy, Putnam and Scarff)

1950’s

-First effective CSF diversion with a one-way valve using biocompatible synthetic materials.  John Holter-1st Silicone Valve   Robert Pudenz-Silicone distal slit valve Peritoneum chosen as better absorptive site than the vascular system

Heyer Schulte and Shunt Industry History

1953:

Dr. Robert Pudenz and W.T. (Ted) Heyer team up on hydrocephalus research

1955

: Pudenz ventriculo-atrial shunt is developed

1959

: Rudy Schulte joins Heyer and Pudenz

1959

: Pudenz flushing valve is developed

1960

: Codman distributes Heyer-Schulte products

1960

: Holter valve is created

1965

: Cordis begins U.S. presence

1965

: Extra-Corporeal buys Holter

1973

: Codman dropped as Heyer-Schulte distributor

Heyer Schulte and Shunt Industry History

1974

: American Hospital Supply buys Heyer-Schulte

1975

: Codman introduces their own product line

1977

: Anasco, PR manufacturing facility is built

1978

: Codman buys Extra-Corporeal

1983

: AHS folds Heyer-Schulte into V. Mueller

1984

: Dr. Pudenz and Rudy Schulte found P-S Medical

1986

: Baxter-Travenol acquires AHS

Heyer Schulte and Shunt Industry History

The 90’s

 NeuroCare Group acquires Heyer-Schulte   Radionics introduces full shunt line Medtronic acquires P-S Medical      Phoenix Biomedical enters the market Codman acquires Cordis Elekta acquires Cordis NMT acquires Cordis Integra acquires Heyer-Schulte

What is a Shunt?

A shunt is a device that diverts CSF from the CNS (usually the lateral ventricle or the lumbar subarachnoid space) to an alternate body cavity (usually the peritoneum or the right atrium) where it is reabsorbed.

How Shunts Work

   Divert CSF from the CNS to another body cavity (R atrium, peritoneum) for absorption.

Mechanical device that regulates flow out of the ventricle.

One-way valve opens when the sum of the forces acting on it exceed some threshold. (the difference between the inlet or ventricular pressure and outlet or peritoneal pressure.

Shunt Systems

   Ventriculo-peritoneal Ventriculo-atrial Lumbar-peritoneal

Shunt Components

Primary Components

   Proximal Catheter Valve (Proximal or Distal) Distal Catheter

Optional Components

  Reservoir Siphon Limiting Mechanism (ASD, SCD, GCD)

Accessories

    Connectors Guides Introducers/Stylets Catheter Passers

SHUNT ACCESSORIES

      Proximal catheter stylet (can use endoscope) Stylets for unitized shunts Shunt passers Connectors and Right angle guides Shunt tap kits Manometers

Valve Mechanisms

  Differential Pressure Valves Flow regulating devices

   

Valve Mechanisms

Differential Pressure Valves Valves open when difference between the ventricular pressure and the peritoneal pressure exceeds some threshold.

Pressure difference at which a valve opens is called the opening pressure.

Pressure difference at which a valve closes is called the closing pressure.

Valve Types

Burr Hole

- shaped to fit the hole made in the skull. The reservoir is an integral part e.g. Pudenz

Flat Bottom

- rests flat against the skull distal to the ventricular catheter e.g. LPV II, Novus

Cylindrical/In Line

appears “seamless” between the ventricular and peritoneal catheters e.g.. Ultra VS

Pudenz

Mishler Dual-Chamber

Ultra VS Cylindrical

One Piece Hydro Shunt

Ommaya

   

Internal Valve Components

Slit Ball and Spring Miter Diaphragm

Valve Mechanisms

Slit Miter

Valve Internal Mechanisms

  High spring rate valves- open slowly, close quickly (miter, slit) Low spring rate valves- open quickly, close slowly (diaphragm, ball & spring, prone to siphon)

Valve Mechanisms

Slit valves

- a slit in a curved rubber layer. The flow arriving from the concave side opens slit, size of opening relating to the upstream pressure Can be proximal or distal Disadvantage:  ”stickiness” of silicone rubber can affect opening   Precision?

Varies with age of valve?

Slit Valves

Codman

    Holter (proximal catheter/valve) Denver (proximal catheter) Accuflo (distal catheter) Uni-shunt (distal catheter)

Radionics

 Proximal slit valve

Phoenix

 Holter-Hausner valve

One Piece Hydro Shunt

Valve Mechanisms

Mitre valves

the leaves of the “duckbill” part in response to the pressure differential. Pressure characteristics of mitre valve are related to size,shape, thickness and length of leaves.

Disadvantage :  “stickiness” of silicone rubber can affect opening

Mitre Valves

Heyer-Schulte

   Ultra-VS(cylindrical) Mishler Dual Chamber (flat bottom) Spetzler in-line Lumbar - Peritoneal valve (cylindrical)

Valve Mechanisms

Spring valves/Ball in cone -

a metallic spring which applies force to a ball (usually ruby or sapphire) located in an orifice. Opening pressure is defined by spring stiffness Disadvantage:   prone to obstruction from CSF debris or high protein content subject to siphoning

Ball-in-Cone Valves

Codman Medos Hakim

 Medos Programmable

NMT/Cordis

  Atlas Hakim  Orbis Sigma II

Sophysa

 Sophy Programmable

Valve Mechanisms

Diaphragm valves -

a round diaphragm rests on or under a valve seat. Pressure causes the diaphragm to be detracted from the seat allowing CSF to flow Disadvantage:  prone to siphoning  in some designs flow is not laminar making it prone to obstruction

Diaphragm Valves

Heyer-Schulte

   Pudenz (burr hole) LPV II (flat bottom) Novus (flat bottom)

PS Medical/Medtronic

  Delta (Burr hole, flat bottom) Button(flat bottom)  Contour (flat bottom)

Diaphragm Valves

Radionics

   Contour Flex Equi-flow Burr hole

Codman

 Accu-flo valve

Valve Mechanisms

   Flow regulating mechanisms Maintains same flow rate at any differential pressure by increasing or lowering its resistance to pressure May be achieved by a solid conical cylinder inserted inside a ring attached to a pressure sensitive membrane

Valve Mechanisms

Inner diameter of ring is greater than larger outer diameter of conical cylinder By reducing surface area, mechanism restricts amount of fluid that can go through Outer cylinder moves to compensate for reduced surface area to maintain flow rate.

Valve Mechanisms

  At very low pressures acts like a DP valve At high pressures the ring moves beyond the central cylinder to give a “blow off” valve.

Treatment for Siphoning

   In a vertical position, negative pressure from hydrostatic column can cause overdrainage Siphoning control achieved by adding siphon resistive devices to the shunt system. Functions as a second valve in line that closes in response to peritoneal pressure

Shunt Failures and Complications

  Shunt failure is at a maximum in first few months after surgery (25-40% at one year follow-up). Then falls to 4-5% The mean survival for a shunt is approx 5 years

Shunt Failures and Complications

      Shunt obstruction (about 50 - 60% of all failures) Infection(between 5 - 10%) Mechanical failure due to disconnection Valve failure Overdrainage Patient/shunt mismatch

Shunt Placement Procedure

       Skin Incision Placement of Burr Hole Sbcutaneous dissection Tunnel the peritoneal catheter Open dura & place ventricular catheter Connect valve, test & clean Distal catheter insertion & skin closure

Shunt Implantation Approaches

Occipital Approach Temporal Approach Frontal Approach

Metopic Suture Coronal Suture Anterior Fontanelle Lamboidal Suture

Skull of a newborn seen from above

Sagittal Suture Posterior Fontanelle

Adult human skull seen from above

Indications For Use of a Lumbar-Peritoneal Shunt

Communicating Hydrocephalus

- when ventricles are small and it would be difficult to cannulate with a ventricular catheter.

Normal Pressure Hydrocephalus

necessitating a cranial procedure.

-

shunting without

Goals of Shunt Design & Development

Restoration of “normal physiology” in the shunted individual Maximize the potential quality of life for each patient Expand the population of successfully treated patients

First Generation Diaphragm Valve

Second Generation Diaphragm Valve

Third Generation Diaphragm Valve

Integra NeuroSciences Consistency by Design

FLOW PATH DELTA VALVE

LPV Valve Performance at High Flow Rates (45.8ml/hr)

12.00

10.00

8.00

6.00

4.00

2.00

0.00

8.00

L/N 1953276 L/N 1953277 LSL USL 6.00

4.00

2.00

0.00

12.00

LPV II Valve Performance at High Flow Rates (45.8ml/hr)

10.00

UNIT NO.

UNIT NO.

L/N 1990108 L/N 1990110 L/N 1991656 L/N 1991553 LSL USL

12.00

LPV Valve Performance at Low Flow Rates (4.6ml/hr)

10.00

8.00

n 6.00

4.00

2.00

0.00

UNIT NO.

12.00

LPV II Valve Performance at Low Flow Rates (4.6ml/hr)

10.00

8.00

L/N 1953276 L/N 1953277 LSL 6.00

USL 4.00

2.00

0.00

UNIT. NO.

L/N 1990108 L/N 1990110 L/N 1991656 L/N 1991553 LSL USL

Competitive Matrix

      Medtronic P.S. Medical Cordis Codman Radionics Sophysa Phoenix

Flat Bottom Diaphragm Competitive Matrix Manufacturer/ Brand Name Heyer-Schulte/N ovus PS Medical/ Delta Valve Mechanism

3rd Generation Diaphragm "T" Valve 2nd Generation Diaphragm

Shape

Flat Bottom Flat Bottom

Radionic's/ Equi-Flow

2nd Generation Diaphragm Flat Bottom

Codman J&J not available Cordis NMT not available Cordis NMT/ Orbis Sigma II

N/A N/A Ball and Spring Flat Bottom

Reservoirs ASD Catalogue # Pricing Other

Proximal, Integral Proximal, Integral Proximal, Integral Yes Normally Open NL850-9010 series depending on pressures and sizes (standard & mini) $665.00 valve only $765.00 kit Yes Normally Closed 42812 series (small) 42822 series (standard) 92822 Regular w/BioGlide 92812 Small w/BioGlide Optional SLR-L, SLR-M (standard) SLS-L, SLS-M (small) $730.00 valve only $840.00 kit $820.00 valve only w/BioGlide $630.00 valve only $780.00 kit Snap Reservoir Option Only available in low and medium pressure 909-612 $675.00 valve only $745.00 kit No peritoneal catheter Flow specified not really equal to others but the Orbis Sigma is their top line valve

Flat Bottom Diaphragm Competitive Matrix Shape Reservoirs ASD Catalogue # Pricing Manufacturer/ Brand Name Heyer-Schulte/ LPV II Valve Mechanism

3rd Generation Diaphragm "T" Valve

PS Medical/ Contour Radionic's/ Contour-Flex

2nd Generation Diaphragm 2nd Generation Diaphragm Flat Bottom Flat Bottom Flat Bottom Proximal, Integral Proximal, Integral Proximal, Integral No No Yes

Other

NL850-9810 series depending on sizes (standard and mini) and pressures (high, medium, low) 42419 series (small) 42322 series (standard) 92322 Regular w/BioGlide 92312 Small w/BioGlide CFR-L, CFR-M, CFR-H (standard) CFS-L, CFS-M, CFS-H (small) $450.00 valve only $595.00 kit $445.00 valve only $505.00 kit $525.00 w/BioGlide BioGlide--- catheter coating $400.00 valve only No kit available

Codman J&J not available Cordis NMT not available

Burr Hole Diaphragm Competitive Matrix Manufacturer/ Brand Name udenz udenz Heyer-Schulte/P Heyer-Schulte/P PS Medical/ Delta Burr Hole Valve Mechanism

3rd Generation Diaphragm "T" Valve 3rd Generation Diaphragm "T" Valve 2nd Generation Diaphragm

PS Medical/ CSF Flow Control Valve Radionic's/ Burr Hole Codman J&J Accuflow

2rd Generation Diaphragm 2nd Generation Diaphragm 2nd Generation Diaphragm

Shape Reservoirs ASD Catalogue # Pricing Other

Burr Hole (12mm and 16mm) Burr Hole (12mm and 16mm) Burr Hole (12mm and 16mm) Burr Hole (12mm and 16mm) Burr Hole (12mm and 16mm) Burr Hole (16mm only) Distal, Integral No NL850-1330 series depending on size and pressure $279.00 valve only Distal, Integral Yes NL850-1410 series depending on size and pressure Proximal, Integral Proximal, Integra Yes No 42832 series (12mm) 42842 series (16mm) 92832 12mm w/BioGlide 92842 16mm w/BioGlide 42542, 42544, 42546 Low, medium, high pressure Distal, Integral No Distal, Integral Optional BHV-12L or BHV-16L Series depending on pressure $569.00 w/ASD valve only $670.00 $765.00 w/BioGlide Snap Reservoir Option $290.00 valve only $270.00

Neonatal Valve Systems Competitive Matrix Shape Reservoirs ASD Catalogue # Pricing Manufacturer/ Brand Name Heyer-Schulte/Ul tra VS Valve Mechanism

Miter Valve

PS Medical/ Ultra Small PS Medical/ Button Codman J&J Cordis NMT/ Omnishunt Neonatal Valve System

2nd Generation Diaphragm 2nd Generation Diaphragm N/A Ball and Spring Cylindrical Flat Bottom Flat Bottom Cylindrical Optional, Proximal Optional, Proximal Optional, Proximal Optional, Proximal

Other

No No No Optional NL850-1126 series depending on size and pressure 42410 series depending on pressure 24003LL series 46544 908-222 series 908-322 series 908-344 series depending on size and pressure $375.00 valve only $625.00 kit $405.00 valve only $625.00 kit $365.00 valve only $580.00 $475.00 Snap Reservoir Option Gravity Compensating Accessory

Product line strengths

      Consistency and predictability Broad product line Clnical support History Manufacturing expertise Pricing flexibility