XIX Congress of the European Society for Pediatric Neurosurgery Rome, May 6-9th 2004

Perspectives of the Shunt Technology: iValve and DigiShunt

Aschoff A, Hashemi B, Scheihing M, Unterberg A, Kremer P

University of Heidelberg, Department of Neurosurgerye-mail: Alfred_Aschoff@med.uni-heidelberg.de

Oral presentation on Sunday, May 9th, 2004 Selected slides

Shunt-Revisions: Quantities

Disconnections

Hydraulic Mismanagement

Infections

Misplaced catheters

Ventricular Catheters - Positions Prospective, 63 EVD-catheters

23.4% Anterior horn, ipsilateral

5.8% Lateral ventricle, ipsilateral5.8% Anterior horn, contralateral

19.3% other positions in the ventricles

2.3% extraventricular intrathecal2.3% in the brain parenchymaWeis N, Naff N, Hanley D: Accuracy of intraventricular

catheter placement ... Poster 221, AANS 2/2003 Phoenix

Tolerance for lateral deviations ±3o only!

±3o Catheter,ideal

position=

all holesfree in the ventricle

Current Quotes of Shunt-Infections Valve Patients Procedures

% n % n Pollack 99 Medos P 9.8 377 Kestle 00 OSV,DP,Delta 8.4 367 Zemack 01 Medos P 11.4 477 8.5 660 Lundkvist 01 Medos P 11.0 122 Götz 01 Medos P 2.8 143 Richards 01 multiple *2.6/6.0 12,950 (*Erst-OP) Vougioukas 01 OSV I+II 8.6 81 Kiefer 01 G-valves 1.7 120 Cochrane 02 multiple 8.6 12,106 Hanlo 03 OSV II 8.2 557 Vinchon 03 multiple 21.7 1564 6.6

1. Sterility in theOP-theatre

2. Antibacterial surface modification of implant

3. Systemic antibiotic prophylaxis

55 rabbits, prospective, randomized Ventricular catheter ± Rifampin (covalent) ± 107 Staph. epiderm., 105 Staph. aureus

- Untreated catheters: 96 % Infections of catheters & brain

- Rifampin-catheters:

0 % Infections of implant p<0,001

Kockro, Aschoff et al. J Med Microbiol 49 (2000):441-450

Simple slit- and diaphragm- valves, Orbis-Sigma:

Inaccuracies & long-term-drifts common

ASD, Delta, distal slit ... : Safety deficits

Instable valve bodiesReflux …

Codman-MedosMiethke ProGAVSophysa-Polaris

+ gravitational valve

Adjustable Valves: Change of Technological Leadership ?

Adjustable Valves – Present Use

Treatment of self-produced complications (preferebly overdrainage)

Fine tuning for individual needs

Training to shunt-independence

Psychotherapy

Adjustable Valves and Shunt-Removal

1. Stepwise increase of valve pressure to 200-400 mmH2O 2. Shunt removal after 1/2 - 2 years

In 59% (71/120) successful!

Takahashi Y (2001) Withdrawal of the shunt systems - clinical use of the programmable shunt system and its effcects in hydrocephalus in children. Child´s Nerv Syst 17:472-477

Adjustable Valves – Use in Future

Treatment of self-produced complications

Fine tuning for individual needs

Psychotherapy

Training to shunt-independence

2 13

Ball- + g-valve

G- + adjustable valve

adjustable alone

Gravitational Valves - Problems

- Complicated stock-keeping in OR 6 supplementary devives (e.g. Shunt-Assistant) 6 complete g-valves (e.g. PaediGAV)

- In case of growth, adipositas, pregnancy, or inadequate pressure selection is under- or (residual) overdrainage not excluded.

- No individual fine-tuning

Gravitational Valves - Perspectives

Adjustable g-Valves

Percutaneous variation

- Number of “active“ balls

- Balls with different weights

- Variation of the cone-geometry

Shunt Technology in 2005

1. Adjustable valve 50-350 mmH2O Stable in MRI, X-ray control not necessary

2. + gravitational valve, adjustable between 100-350 mmH2O, stable during jogging etc.

3. + low-flow-catheter (ID Ø 0.8 mm)

4. ICP-telemetry (sensor intradural)

5. Incorporated antibiotics

Shunt Technology in 2010

- 2 intracranial microtransducers - 2 extrathecal transducers - 2 gravitational chip sensors - Storage chip: ICP of last month - Telemetry - Electronically controlled valve - CPU, programmable for an “event- controlled” shunt function and training to shunt-independence