OBJECTIVES: The objective of the UK Shunt Evaluation Laboratory was to perform an independent testing of hydrodynamic performance of hydrocephalus shunts and provide systematic reviewing for neurosurgeons and patients. METHODS: Valves were tested long-term in a computer-controlled rig to evaluate their pressure-flow performance both at baseline and under conditions mimicking phenomena, which may alter CSF drainage in vivo. The operating pressures (Poperating) and hydrodynamic resistances (R) of all types of valves, currently in use in the UK, have been evaluated (Codman: Hakim-Precision, Hakim-Programmable, Uni-Shunt, Accu-flo, Holter. Medtronic PS Medical: Delta, Flow Control, Lumbo-peritoneal. NMT: Orbis-Sigma, Omni-shunt, Hakim Valve. Heyer-Schulte: In-line, Pudenz-Flushing, LowProfile. Radionics ContourFlex. Sophy Programmable). 67 patients, who had improved in the past following shunting but had recent recurrence of their clinical symptoms, were admitted to undergo a computerized infusion test through the shunt pre-chamber or Ommaya reservoir implanted prior to shunting. The criterion used to detect shunt underdrainage was an increase in ICP during constant infusion above (Poperating) + R * Infusion rate + 5 mm Hg. The validity of this formula has been confirmed in a laboratory study. RESULTS: 35 patients met the criteria for shunt underdrainage while in 24 normal drainage was demonstrated. Mean ICP achieved during the test was 24 mm Hg in patients with underdrainage versus 14 mm Hg with normally functioning shunts (p < 0.01). Out of 35 patients 25 improved and 10 were seen again to have the test repeated. In 7 patients shunt was blocked again. Only 3 patients with primarily confirmed shunt underdrainage did not improve following revisions. In 8 patients overdrainage related to body posture was confirmed using tilt-test. CONCLUSIONS: Shunt testing in-vivo is easy, clinically useful and has good prediction power (90%).
OBJECTIVES: The objective of the UK Shunt Evaluation Laboratory was to perform an independent testing of hydrodynamic performance of hydrocephalus shunts and provide systematic reviewing for neurosurgeons and patients. METHODS: Valves were tested long-term in a computer-controlled rig to evaluate their pressure-flow performance both at baseline and under conditions mimicking phenomena, which may alter CSF drainage in vivo. The operating pressures (Poperating) and hydrodynamic resistances (R) of all types of valves, currently in use in the UK, have been evaluated (Codman: Hakim-Precision, Hakim-Programmable, Uni-Shunt, Accu-flo, Holter. Medtronic PS Medical: Delta, Flow Control, Lumbo-peritoneal. NMT: Orbis-Sigma, Omni-shunt, Hakim Valve. Heyer-Schulte: In-line, Pudenz-Flushing, LowProfile. Radionics ContourFlex. Sophy Programmable). 67 patients, who had improved in the past following shunting but had recent recurrence of their clinical symptoms, were admitted to undergo a computerized infusion test through the shunt pre-chamber or Ommaya reservoir implanted prior to shunting. The criterion used to detect shunt underdrainage was an increase in ICP during constant infusion above (Poperating) + R * Infusion rate + 5 mm Hg. The validity of this formula has been confirmed in a laboratory study. RESULTS: 35 patients met the criteria for shunt underdrainage while in 24 normal drainage was demonstrated. Mean ICP achieved during the test was 24 mm Hg in patients with underdrainage versus 14 mm Hg with normally functioning shunts (p < 0.01). Out of 35 patients 25 improved and 10 were seen again to have the test repeated. In 7 patients shunt was blocked again. Only 3 patients with primarily confirmed shunt underdrainage did not improve following revisions. In 8 patients overdrainage related to body posture was confirmed using tilt-test. CONCLUSIONS: Shunt testing in-vivo is easy, clinically useful and has good prediction power (90%).
Authors: Sandra Fernandes Dias; Afroditi-Despina Lalou; Regine Spang; Karin Haas-Lude; Matthew Garnett; Helen Fernandez; Marek Czosnyka; Martin U Schuhmann; Zofia Czosnyka Journal: Childs Nerv Syst Date: 2019-08-01 Impact factor: 1.475
Authors: Anders Eklund; Lars-Owe D Koskinen; Michael A Williams; Mark G Luciano; Stephen M Dombrowski; Jan Malm Journal: Fluids Barriers CNS Date: 2012-06-29
Authors: Anders Eklund; Peter Smielewski; Iain Chambers; Noam Alperin; Jan Malm; Marek Czosnyka; Anthony Marmarou Journal: Med Biol Eng Comput Date: 2007-07-17 Impact factor: 2.602
Authors: Luis Garegnani; Juan Va Franco; Agustín Ciapponi; Virginia Garrote; Valeria Vietto; Santiago Adalberto Portillo Medina Journal: Cochrane Database Syst Rev Date: 2020-06-16