Article
Codman-Hakim programmable valve dysfunction after using VPV Programmer
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Authors
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Leonhard Rensch
- Universitätsklinikum Halle (Saale), Universitätsklinik und Poliklink für Neurochirurgie, Halle (Saale), Deutschland
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Sebastian Simmermacher
- Universitätsklinikum Halle-Wittenberg, Neurochirurgische Klinik, Halle (Saale), Deutschland
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Christian Strauss
- Universitätsklinikum Halle/Saale, Klinik und Poliklinik für Neurochirurgie, Halle/Saale, Deutschland
| Published: | June 9, 2017 |
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Outline
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Objective: The authors report a rare case of detachment of the pressure control cam in Codman-Hakim programmable valve (CHPV) after using the valve position verification (VPV) Programmer.
Methods: A 6-year old girl came to our hospital for a preplanned abdominal catheter revision due to growth. The ventriculo-peritoneal shunt system with CHPV system was implanted because of a posthaemorragic hydrocephalus after prematurity. There were no clinical symptoms of shuntdysfunction in the examination and no reports of headache or nausea in the past. Routine radiography after performing a 1.5-T MRI scan on the same day showed the CHPV with normal appearance. Because a different pressure-level was documented we readjusted the CHPV using the Codman VPV Programmer. The radiography after adjustment showed a dislocation of the pressure control cam.
Results: After the explantation and replacement a careful examination of the CHPV did not reveal any sign of destruction of the plastic housing of the valve while a complete detachment of the pressure control cam from the base-plate in the valve system was observed. The detachment caused the cam to move away from the flat spring that normally presses down the valve ball resulting in an obviously dysfunctional valve. In the interview of the patient and the mother none of them could remember a previous trauma causing a mechanical impact on the valve. There are few case reports about loosened pressure cams after some form of mechanical shock and a single report after a 3-T MRI scan. In these cases a breakage of the plastic housing was observed. According to the authors knowledge this is the first reported case of a detachment of the pressure control cam in CHPV after using the VPV Programmer. A traumatic damage in the past could not be ruled out completely but seemed unlikely in respect of the anamnesis and the described findings. The radiography was performed after the MRI scan and showed a regular configuration of the valve but a changed pressure level implying a normal function.
Conclusion: Dislocation of a pressure control cam in CHPV is a rare condition. The authors report this case of CHPV dysfunction after using VPV Programmer to encourage a dialogue if there are any similar cases known. In that case some considerations about prophylactic resetting CHPV to the former pressure level after MRI without previous radiography should be made.
