hydrocephalus and neuro shunting

Hydrocephalus and Neuro Shunting

Sales TrainingApril 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. - Arachnoid A.G. - Arachnoid Granulation B. - Bone C.A. - Cerebral Artery C.V. - Cerebral Vein D. - Dura Mater F.C. - Falx Cerebri P.M. - Pia Mater S. - SkinS.A.S. - Sub-Arachnoid SpaceS.D.S. - Sub-Dural SpaceS.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 severehydrocephalus

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 HydrocephalusInfants

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 ModalitiesSurgical Procedures

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

Interventions for HydrocephalusIf untreated:

*50-60% die of complications

If treated:

*40% normal intelligence

*70% live beyond infancy

Questions???

Historical Treatment of HydrocephalousHippocrates 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’t1922-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 History1953: 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 History1974: 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 HistoryThe 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 TypesBurr 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 MechanismsSlit 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 ValvesCodman

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 MechanismsMitre 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 ValvesHeyer-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 MechanismsDiaphragm 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)

Radionics Contour Flex Equi-flow Burr hole

Codman Accu-flo valve

Diaphragm Valves

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 isgreater than largerouter diameter ofconical cylinder

By reducing surfacearea, mechanismrestricts amount of fluidthat can go through

Outer cylinder movesto compensate forreduced surface areato 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.

Valve Mechanisms

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

Skull of a newborn seen from above Adult human skull seen from above

LamboidalSuture

PosteriorFontanelle

SagittalSuture

AnteriorFontanelle

MetopicSuture

CoronalSuture

Indications For Use of a Lumbar-Peritoneal ShuntCommunicating Hydrocephalus - when ventricles are

small and it would be difficult to cannulate with a ventricular catheter.

Normal Pressure Hydrocephalus - shunting without necessitating a cranial procedure.

Goals of Shunt Design & DevelopmentRestoration 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 NeuroSciencesConsistency by Design

FLOW PATH

DELTA VALVE

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

LPV Valve Performanceat High Flow Rates (45.8ml/hr)

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

LPV Valve Performanceat Low Flow Rates (4.6ml/hr)

Competitive Matrix Medtronic P.S. Medical Cordis Codman Radionics Sophysa Phoenix

Flat Bottom Diaphragm Competitive MatrixManufacturer/

Brand Name Valve

Mechanism Shape Reservoirs ASD Catalogue # Pricing Other

Heyer-Schulte/Novus

3rd Generation Diaphragm "T" Valve

Flat Bottom Proximal, Integral

Yes Normally

Open

NL850-9010 series depending on pressures and

sizes (standard & mini)

$665.00 valve only

$765.00 kit

PS Medical/ Delta

2nd Generation Diaphragm

Flat Bottom Proximal, Integral

Yes Normally

Closed

42812 series (small)

42822 series (standard)

92822 Regular w/BioGlide

92812 Small w/BioGlide

$730.00 valve only

$840.00 kit

$820.00 valve only w/BioGlide

Snap Reservoir Option

Radionic's/ Equi-Flow

2nd Generation Diaphragm

Flat Bottom Proximal, Integral

Optional SLR-L, SLR-M (standard)

SLS-L, SLS-M (small)

$630.00 valve only

$780.00 kit

Only available in low and medium pressure

Codman J&J not available

N/A

Cordis NMT not available

N/A

Cordis NMT/ Orbis Sigma II

Ball and Spring

Flat Bottom 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

Manufacturer/ Brand Name

Valve Mechanism

Shape Reservoirs ASD Catalogue # Pricing Other

Heyer-Schulte/ LPV II

3rd Generation Diaphragm "T" Valve

Flat Bottom Proximal, Integral

No NL850-9810 series depending on sizes

(standard and mini) and pressures (high, medium, low)

$450.00 valve only

$595.00 kit

PS Medical/ Contour

2nd Generation Diaphragm

Flat Bottom Proximal, Integral

No 42419 series (small)

42322 series (standard)

92322 Regular w/BioGlide

92312 Small w/BioGlide

$445.00 valve only

$505.00 kit

$525.00 w/BioGlide

BioGlide---

catheter coating

Radionic's/ Contour-Flex

2nd Generation Diaphragm

Flat Bottom Proximal, Integral

Yes CFR-L, CFR-M, CFR-H (standard)

CFS-L, CFS-M, CFS-H (small)

$400.00 valve only

No kit available

Codman J&J not available

Cordis NMT not available

Flat Bottom Diaphragm Competitive Matrix

Burr Hole Diaphragm Competitive MatrixManufacturer/ Brand Name

Valve Mechanism

Shape Reservoirs ASD Catalogue # Pricing Other

Heyer-Schulte/Pudenz

3rd Generation Diaphragm "T" Valve

Burr Hole (12mm and

16mm)

Distal, Integral No NL850-1330 series depending on size and

pressure

$279.00 valve only

Heyer-Schulte/Pudenz

3rd Generation Diaphragm "T" Valve

Burr Hole (12mm and

16mm)

Distal, Integral Yes NL850-1410 series depending on size and

pressure

$569.00 w/ASD

valve only

PS Medical/ Delta Burr Hole

2nd Generation Diaphragm

Burr Hole (12mm and

16mm)

Proximal, Integral

Yes 42832 series (12mm)

42842 series (16mm)

92832 12mm w/BioGlide

92842 16mm w/BioGlide

$670.00

$765.00 w/BioGlide

Snap Reservoir Option

PS Medical/ CSF Flow

Control Valve

2rd Generation Diaphragm

Burr Hole (12mm and

16mm)

Proximal, Integra

No 42542, 42544, 42546 Low, medium, high

pressure

$290.00 valve only

Radionic's/ Burr Hole

2nd Generation Diaphragm

Burr Hole (12mm and

16mm)

Distal, Integral No BHV-12L or BHV-16L Series depending on

pressure

$270.00

Codman J&J Accuflow

2nd Generation Diaphragm

Burr Hole (16mm only)

Distal, Integral Optional

Neonatal Valve Systems Competitive MatrixManufacturer/ Brand Name

Valve Mechanism

Shape Reservoirs ASD Catalogue # Pricing Other

Heyer-Schulte/Ultra VS

Miter Valve Cylindrical Optional, Proximal

No NL850-1126 series depending on size and

pressure

$375.00 valve only

$625.00 kit

PS Medical/ Ultra Small

2nd Generation Diaphragm

Flat Bottom Optional, Proximal

No 42410 series depending on pressure

$405.00 valve only

$625.00 kit

Snap Reservoir Option

PS Medical/ Button

2nd Generation Diaphragm

Flat Bottom Optional, Proximal

No 24003LL series

$365.00 valve only

$580.00

Codman J&J N/A

Cordis NMT/ Omnishunt

Neonatal Valve System

Ball and Spring

Cylindrical Optional, Proximal

Optional 908-222 series

908-322 series

908-344 series depending on size and

pressure

$475.00 Gravity Compensating

Accessory

46544

Product line strengths

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