A retrospective review demonstrated that the valve opening pressure is an important component of the shunt complication rate 1)
Neurosurgeons select a valve opening pressure (VOP), whose exceeding causes the shunt to open to drain cerebrospinal fluid (CSF): In most cases a standard pressure is chosen. Whereas some patients fare well with the primary chosen VOP, others require one to several VOP changes.
A study of Müggenburg et al. from the University Hospital Frankfurt aimed to evaluate the prevalence and indication for occurring valve pressure-adjustments.
They obtained information about 343 ventriculoperitoneal shunt implantations in 321 adult patients from 2013 to 2018 in a single center with well-kept electronic health records regarding hydrocephalus types, hydrocephalus etiologies, primary VOP, valve pressure adjustment, time with shunt, time till VOP change, age, sex and shunt type. The data was analyzed using Kaplan-Meier estimator (KME) for the whole patient sample and for subgroups with the primary VOP adjustment defined as event. In the subgroup analysis different types of hydrocephalus, different hydrocephalus etiologies, valve types, both sexes and the patients' age had been compared by applying Peto-Pike's log-rank test and cox regression.
Of the 343 implanted VP shunts in 321 patients, 166 valve pressure adjustments in 101 V P shunts were required during the observed time with a resulting valve pressure-adjustment rate of 0.484 per valve implant. The time till median valve pressure-adjustment was 2.9 years and 38.3% one year after VP shunt placement for the general sample in Kaplan Meier-analysis. The subgroup comparisons between hydrocephalus types, hydrocephalus etiologies, valve types, sexes and the patients' age did not reveal significant differences applying Peto-Pike's log-rank test. But the primary chosen valve-pressure of 5 cmH2O is associated with a lower percentage of valve-pressure adjustments, than other initial valve-pressures (Chi2 = 7.9; df = 1; p = 0.0049).
This study reveals a valve pressure-adjustment rate of 38.3% after one year for the whole patient collective and similar adjustment rates for different types of hydrocephalus. The primary valve pressure of 5 cmH2O is associated with a lower valve pressure-adjustment rate than other initial valve pressures and therefore 5 cmH2O may be the preferred initial valve pressure for all patients receiving programmable VP shunt insertions with gravitational unit 2).
2: Prickett J, Altafulla J, Knisely A, Litvack Z. Invasive Cryptococcal Meningitis Presenting as a Skull Base Mass in An Immunocompetent Host: A Case Report. J Neurol Surg Rep. 2019 Jul;80(3):e31-e35. doi: 10.1055/s-0039-1687886. Epub 2019 Jul 18. PubMed PMID: 31328082; PubMed Central PMCID: PMC6639088.
3: Todisco M, Pozzi NG, Zangaglia R, Minafra B, Servello D, Ceravolo R, Alfonsi E, Fasano A, Pacchetti C. Pisa syndrome in Idiopathic Normal Pressure Hydrocephalus. Parkinsonism Relat Disord. 2019 Jun 28. pii: S1353-8020(19)30287-1. doi: 10.1016/j.parkreldis.2019.06.024. [Epub ahead of print] PubMed PMID: 31300263.
4: Giordan E, Palandri G, Lanzino G, Murad MH, Elder BD. Outcomes and complications of different surgical treatments for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis. J Neurosurg. 2018 Nov 1:1-13. doi: 10.3171/2018.5.JNS1875. [Epub ahead of print] Review. PubMed PMID: 30497150.
5: Sandvig A, Arnell K, Malm J, Eklund A, Koskinen LD. Analysis of Codman microcerebrospinal fluid shunt. Brain Behav. 2018 Oct;8(10):e01002. doi: 10.1002/brb3.1002. Epub 2018 Sep 11. PubMed PMID: 30207083; PubMed Central PMCID: PMC6192409.
6: Feletti A, d'Avella D, Wikkelsø C, Klinge P, Hellström P, Tans J, Kiefer M, Meier U, Lemcke J, Paternò V, Stieglitz L, Sames M, Saur K, Kordás M, Vitanovic D, Gabarrós A, Llarga F, Triffaux M, Tyberghien A, Juhler M, Hasselbalch S, Cesarini K, Laurell K. Ventriculoperitoneal Shunt Complications in the European Idiopathic Normal Pressure Hydrocephalus Multicenter Study. Oper Neurosurg (Hagerstown). 2019 Jul 1;17(1):97-102. doi: 10.1093/ons/opy232. PubMed PMID: 30169650.
7: Hasegawa H, Shin M, Kondo K, Saito N. Reconstruction of Dural Defects in Endoscopic Transnasal Approaches for Intradural Lesions Using Multilayered Fascia with a Pressure-Control Spinal Drainage System. World Neurosurg. 2018 Jun;114:e1316-e1324. doi: 10.1016/j.wneu.2018.03.209. Epub 2018 Apr 6. PubMed PMID: 29631081.
8: Karsy M, Abou-Al-Shaar H, Bowers CA, Schmidt RH. Treatment of idiopathic intracranial hypertension via stereotactic placement of biventriculoperitoneal shunts. J Neurosurg. 2018 Feb 2;130(1):136-144. doi: 10.3171/2017.8.JNS162927. PubMed PMID: 29393752.
9: Lefevre E, Montero AS, Bernardeschi D, Kalamarides M. Spontaneously Resolving Symptomatic Subdural Hygromas After Cerebellopontine Angle Tumor Surgery. World Neurosurg. 2018 Feb;110:35-38. doi: 10.1016/j.wneu.2017.10.114. Epub 2017 Oct 31. PubMed PMID: 29101072.
10: Bozhkov Y, Roessler K, Hore N, Buchfelder M, Brandner S. Neurological outcome and frequency of overdrainage in normal pressure hydrocephalus directly correlates with implanted ventriculo-peritoneal shunt valve type. Neurol Res. 2017 Jul;39(7):601-605. doi: 10.1080/01616412.2017.1321300. Epub 2017 May 1. PubMed PMID: 28460569.
11: Ozturk S, Cakin H, Kurtuldu H, Kocak O, Erol FS, Kaplan M. Smartphones and Programmable Shunts: Are These Indispensable Phones Safe and Smart? World Neurosurg. 2017 Jun;102:518-525. doi: 10.1016/j.wneu.2017.03.054. Epub 2017 Mar 22. PubMed PMID: 28342922.
12: Cheng Z, Wang W, Han Y, Liu J, Wang Z, Zhou Y, Li F, Huang Y. Low pressure hydrocephalus: clinical manifestations, radiological characteristics, and treatment. Br J Neurosurg. 2017 Aug;31(4):410-414. doi: 10.1080/02688697.2017.1297383. Epub 2017 Mar 6. PubMed PMID: 28264586.
13: Lee JB, Ahn HY, Lee HJ, Yang JH, Yi JS, Lee IW. Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions. J Korean Neurosurg Soc. 2017 Jan 1;60(1):1-7. doi: 10.3340/jkns.2016.0404.002. Epub 2016 Dec 29. PubMed PMID: 28061484; PubMed Central PMCID: PMC5223762.
14: Karakis I, Nuccio AH, Amadio JP, Fountain AJ Jr. The Monro-Kellie Doctrine in Action: Posterior Reversible Leukoencephalopathy Syndrome Caused by Intracranial Hypotension from Lumboperitoneal Shunt Placement. World Neurosurg. 2017 Feb;98:868.e11-868.e15. doi: 10.1016/j.wneu.2016.12.046. Epub 2016 Dec 23. PubMed PMID: 28017759.
15: Diesner N, Freimann F, Clajus C, Kallenberg K, Rohde V, Stockhammer F. Female gender predisposes for cerebrospinal fluid overdrainage in ventriculoperitoneal shunting. Acta Neurochir (Wien). 2016 Jul;158(7):1273-8. doi: 10.1007/s00701-016-2827-z. Epub 2016 May 13. PubMed PMID: 27177735.
16: Gebert AF, Schulz M, Schwarz K, Thomale UW. Long-term survival rates of gravity-assisted, adjustable differential pressure valves in infants with hydrocephalus. J Neurosurg Pediatr. 2016 May;17(5):544-51. doi: 10.3171/2015.10.PEDS15328. Epub 2016 Jan 22. PubMed PMID: 26799410.
17: Maeske M, Mayer S, Blanc SM, Schulz C, Kunz U, Mauer UM. Telemetric Intracranial Pressure Measurement: A Graphical Approach to Data Analysis. J Neurol Surg A Cent Eur Neurosurg. 2016 May;77(3):258-63. doi: 10.1055/s-0035-1566117. Epub 2015 Nov 20. PubMed PMID: 26588254.
18: Fotakopoulos G, Tsianaka E, Siasios G, Vagkopoulos K, Fountas K. Posttraumatic Hydrocephalus after Decompressive Craniectomy in 126 Patients with Severe Traumatic Brain Injury. J Neurol Surg A Cent Eur Neurosurg. 2016 Mar;77(2):88-92. doi: 10.1055/s-0035-1558411. Epub 2015 Sep 9. PubMed PMID: 26351868.
19: Farahmand D, Sæhle T, Eide PK, Tisell M, Hellström P, Wikkelsö C. A double-blind randomized trial on the clinical effect of different shunt valve settings in idiopathic normal pressure hydrocephalus. J Neurosurg. 2016 Feb;124(2):359-67. doi: 10.3171/2015.1.JNS141301. Epub 2015 Aug 28. PubMed PMID: 26315004.
20: Sakka L, Chomicki A, Gabrillargues J, Khalil T, Chazal J, Avan P. Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus. J Neurosurg. 2016 Feb;124(2):342-9. doi: 10.3171/2015.1.JNS142142. Epub 2015 Aug 21. PubMed PMID: 26295913.
21: Kehler U, Kiefer M, Eymann R, Wagner W, Tschan CA, Langer N, Rohde V, Ludwig HC, Gliemroth J, Meier U, Lemcke J, Thomale UW, Fritsch M, Krauss JK, Mirzayan MJ, Schuhmann M, Huthmann A. PROSAIKA: a prospective multicenter registry with the first programmable gravitational device for hydrocephalus shunting. Clin Neurol Neurosurg. 2015 Oct;137:132-6. doi: 10.1016/j.clineuro.2015.07.002. Epub 2015 Jul 8. PubMed PMID: 26196478.
22: Alkherayf F, Abou Al-Shaar H, Awad M. Management of idiopathic intracranial hypertension with a programmable lumboperitoneal shunt: Early experience. Clin Neurol Neurosurg. 2015 Sep;136:5-9. doi: 10.1016/j.clineuro.2015.05.018. Epub 2015 May 27. PubMed PMID: 26056804.
23: Symss NP, Oi S. Is there an ideal shunt? A panoramic view of 110 years in CSF diversions and shunt systems used for the treatment of hydrocephalus: from historical events to current trends. Childs Nerv Syst. 2015 Feb;31(2):191-202. doi: 10.1007/s00381-014-2608-z. Epub 2014 Dec 30. Review. PubMed PMID: 25547875.
24: Montemurro N, Cocciaro A, Meola A, Lutzemberger L, Vannozzi R. Hydrocephalus following bilateral dumbbell-shaped c2 spinal neurofibromas resection and postoperative cervical pseudomeningocele in a patient with neurofibromatosis type 1: a case report. Evid Based Spine Care J. 2014 Oct;5(2):136-8. doi: 10.1055/s-0034-1387805. PubMed PMID: 25364327; PubMed Central PMCID: PMC4212698.
25: Sæhle T, Farahmand D, Eide PK, Tisell M, Wikkelsö C. A randomized controlled dual-center trial on shunt complications in idiopathic normal-pressure hydrocephalus treated with gradually reduced or “fixed” pressure valve settings. J Neurosurg. 2014 Nov;121(5):1257-63. doi: 10.3171/2014.7.JNS14283. Epub 2014 Sep 5. PubMed PMID: 25192478.
26: Malem DN, Shand Smith JD, Toma AK, Sethi H, Kitchen ND, Watkins LD. An investigation into the clinical impacts of lowering shunt opening pressure in idiopathic normal pressure hydrocephalus: A case series. Br J Neurosurg. 2015 Feb;29(1):18-22. doi: 10.3109/02688697.2014.950630. Epub 2014 Aug 21. PubMed PMID: 25142701.
27: Farahmand D, Qvarlander S, Malm J, Wikkelsö C, Eklund A, Tisell M. Intracranial pressure in hydrocephalus: impact of shunt adjustments and body positions. J Neurol Neurosurg Psychiatry. 2015 Feb;86(2):222-8. doi: 10.1136/jnnp-2014-307873. Epub 2014 Jun 24. PubMed PMID: 24963125.
28: Freimann FB, Luhdo ML, Rohde V, Vajkoczy P, Wolf S, Sprung C. The Frankfurt horizontal plane as a reference for the implantation of gravitational units: a series of 376 adult patients. Acta Neurochir (Wien). 2014 Jul;156(7):1351-6. doi: 10.1007/s00701-014-2076-y. Epub 2014 May 4. PubMed PMID: 24792967.
29: Tschan CA, Antes S, Huthmann A, Vulcu S, Oertel J, Wagner W. Overcoming CSF overdrainage with the adjustable gravitational valve proSA. Acta Neurochir (Wien). 2014 Apr;156(4):767-76; discussion 776. doi: 10.1007/s00701-013-1934-3. Epub 2013 Nov 30. PubMed PMID: 24292775.
30: Gölz L, Lemcke J, Meier U. Indications for valve-pressure adjustments of gravitational assisted valves in patients with idiopathic normal pressure hydrocephalus. Surg Neurol Int. 2013 Oct 15;4:140. doi: 10.4103/2152-7806.119879. eCollection 2013. PubMed PMID: 24231878; PubMed Central PMCID: PMC3814988.
31: Freimann FB, Ötvös J, Chopra SS, Vajkoczy P, Wolf S, Sprung C. Differential pressure in shunt therapy: investigation of position-dependent intraperitoneal pressure in a porcine model. J Neurosurg Pediatr. 2013 Dec;12(6):575-81. doi: 10.3171/2013.8.PEDS13205. Epub 2013 Oct 4. PubMed PMID: 24093588.
32: Stockhammer F, Miethke C, Knitter T, Rohde V, Sprung C. Flow-related noise in patients with ventriculoperitoneal shunt using gravitational adjustable valves. Acta Neurochir (Wien). 2014 Apr;156(4):761-5. doi: 10.1007/s00701-013-1876-9. Epub 2013 Sep 19. PubMed PMID: 24048819.
33: Khan QU, Wharen RE, Grewal SS, Thomas CS, Deen HG Jr, Reimer R, Van Gerpen JA, Crook JE, Graff-Radford NR. Overdrainage shunt complications in idiopathic normal-pressure hydrocephalus and lumbar puncture opening pressure. J Neurosurg. 2013 Dec;119(6):1498-502. doi: 10.3171/2013.7.JNS13484. Epub 2013 Aug 9. PubMed PMID: 23930853.
34: Preuß M, Evangelou P, Hirsch W, Reiss-Zimmermann M, Fischer L, Merkenschlager A, Kieß W, Siekmeyer M, Meixensberger J, Nestler U. Acute two-compartment low pressure hydrocephalus–a case report. Childs Nerv Syst. 2013 Dec;29(12):2307-10. doi: 10.1007/s00381-013-2173-x. Epub 2013 May 29. PubMed PMID: 23715811.
35: Muehlmann M, Koerte IK, Laubender RP, Steffinger D, Lehner M, Peraud A, Heinen F, Kiefer M, Reiser M, Ertl-Wagner B. Magnetic resonance-based estimation of intracranial pressure correlates with ventriculoperitoneal shunt valve opening pressure setting in children with hydrocephalus. Invest Radiol. 2013 Jul;48(7):543-7. doi: 10.1097/RLI.0b013e31828ad504. PubMed PMID: 23695081.
36: Oliveira MF, Saad F, Reis RC, Rotta JM, Pinto FC. Programmable valve represents an efficient and safe tool in the treatment of idiopathic normal-pressure hydrocephalus patients. Arq Neuropsiquiatr. 2013 Apr;71(4):229-36. PubMed PMID: 23588284.
37: Aguas J, Rodrigo V, Estupiñan F, Nogues P, Villalba G, Villagrasa J, Caral L. [Normal pressure hydrocephalus: prognostic value of height in patients treated with an identical shunt system]. Neurocirugia (Astur). 2013 May-Jun;24(3):102-9. doi: 10.1016/j.neucir.2013.01.005. Epub 2013 Mar 29. Spanish. PubMed PMID: 23541788.
38: Yoon MK, Parsa AT, Horton JC. Skull thickening, paranasal sinus expansion, and sella turcica shrinkage from chronic intracranial hypotension. J Neurosurg Pediatr. 2013 Jun;11(6):667-72. doi: 10.3171/2013.2.PEDS12560. Epub 2013 Mar 29. PubMed PMID: 23540524.
39: Delwel EJ, de Jong DA, Dammers R, Kurt E, van den Brink W, Dirven CM. A randomised trial of high and low pressure level settings on an adjustable ventriculoperitoneal shunt valve for idiopathic normal pressure hydrocephalus: results of the Dutch evaluation programme Strata shunt (DEPSS) trial. J Neurol Neurosurg Psychiatry. 2013 Jul;84(7):813-7. doi: 10.1136/jnnp-2012-302935. Epub 2013 Feb 13. PubMed PMID: 23408069.
40: Elixmann IM, Goffin C, Krueger R, Meier U, Lemcke J, Kiefer M, Antes S, Leonhardt S. Case study of relevant pressures for an implanted hydrocephalus valve in everyday life. Conf Proc IEEE Eng Med Biol Soc. 2012;2012:1635-8. doi: 10.1109/EMBC.2012.6346259. PubMed PMID: 23366220.
41: Czosnyka Z, Pickard JD, Czosnyka M. Hydrodynamic properties of the Certas hydrocephalus shunt. J Neurosurg Pediatr. 2013 Feb;11(2):198-204. doi: 10.3171/2012.10.PEDS12239. Epub 2012 Dec 7. PubMed PMID: 23215818.
42: Freimann FB, Sprung C. Shunting with gravitational valves–can adjustments end the era of revisions for overdrainage-related events?: clinical article. J Neurosurg. 2012 Dec;117(6):1197-204. doi: 10.3171/2012.8.JNS1233. Epub 2012 Sep 21. PubMed PMID: 22998061.
43: Watt S, Agerlin N, Romner B. Initial experience with the Codman Certas adjustable valve in the management of patients with hydrocephalus. Fluids Barriers CNS. 2012 Sep 20;9(1):21. doi: 10.1186/2045-8118-9-21. PubMed PMID: 22995221; PubMed Central PMCID: PMC3490860.
44: Trinh VT, Duckworth EA. Revision to an adjustable non-siphon control valve in low pressure hydrocephalus: therapeutic siphoning and a new perspective on NPH: series of 3 cases and review of the literature. Clin Neurol Neurosurg. 2013 Feb;115(2):175-8. doi: 10.1016/j.clineuro.2012.05.017. Epub 2012 Jul 4. PubMed PMID: 22770726.
45: Kataria R, Kumar V, Mehta VS. Programmable valve shunts: are they really better? Turk Neurosurg. 2012;22(2):237-8. doi: 10.5137/1019-5149.JTN.3011-10.1. PubMed PMID: 22437300.
46: Katano H, Matsuo S, Yamada K. Disproportionately large communicating fourth ventricle resulting from adjustable valve shunt in an infant. Acta Neurol Belg. 2012 Mar;112(1):91-3. doi: 10.1007/s13760-012-0031-3. Epub 2012 Jan 26. PubMed PMID: 22427298.
47: Medow JE, Luzzio CC. Posture-independent piston valve: a novel valve mechanism that actuates based on intracranial pressure alone. J Neurosurg Pediatr. 2012 Jan;9(1):64-8. doi: 10.3171/2011.10.PEDS1182. PubMed PMID: 22208323.
48: Tsuang FY, Huang AP, Tsai YH, Chen JY, Lee JE, Tu YK, Wang KC. Treatment of patients with traumatic subdural effusion and concomitant hydrocephalus. J Neurosurg. 2012 Mar;116(3):558-65. doi: 10.3171/2011.10.JNS11711. Epub 2011 Dec 16. PubMed PMID: 22175725.
49: Chrissicopoulos C, Mourgela S, Kirgiannis K, Sakellaropoulos A, Ampertos N, Petritsis K, Spanos A. What is the appropriate shunt system for normal pressure hydrocephalus? Acta Neurochir Suppl. 2012;113:119-21. doi: 10.1007/978-3-7091-0923-6_24. PubMed PMID: 22116436.
50: Elixmann IM, Walter M, Kiefer M, Leonhardt S. Simulation of existing and future electromechanical shunt valves in combination with a model for brain fluid dynamics. Acta Neurochir Suppl. 2012;113:77-81. doi: 10.1007/978-3-7091-0923-6_16. PubMed PMID: 22116428.
51: Miranda P, Simal JA, Menor F, Plaza E, Conde R, Botella C. Initial proximal obstruction of ventriculoperitoneal shunt in patients with preterm-related posthaemorrhagic hydrocephalus. Pediatr Neurosurg. 2011;47(2):88-92. doi: 10.1159/000329622. Epub 2011 Sep 23. PubMed PMID: 21952534.
52: Nakashima K, Nakajo T, Kawamo M, Kato A, Ishigaki S, Murakami H, Imaizumi Y, Izumiyama H. Programmable shunt valves: in vitro assessment of safety of the magnetic field generated by a portable game machine. Neurol Med Chir (Tokyo). 2011;51(9):635-8. PubMed PMID: 21946726.
53: Aihara N, Mase M, Nishikawa Y, Ohno T, Yamada K. Lumbar peritoneal shunt containing a programmable valve for intracranial hypertension caused by Borden type 1 dural arteriovenous fistulas. Acta Neurochir (Wien). 2011 Nov;153(11):2219-23. doi: 10.1007/s00701-011-1134-y. Epub 2011 Aug 31. PubMed PMID: 21879338.
54: Filippidis AS, Kalani MY, Nakaji P, Rekate HL. Negative-pressure and low-pressure hydrocephalus: the role of Cerebrospinal fluid fistulas resulting from surgical approaches to the cranial base. J Neurosurg. 2011 Nov;115(5):1031-7. doi: 10.3171/2011.6.JNS101504. Epub 2011 Jul 29. PubMed PMID: 21800965.
55: Toma AK, Tarnaris A, Kitchen ND, Watkins LD. Use of the proGAV shunt valve in normal-pressure hydrocephalus. Neurosurgery. 2011 Jun;68(2 Suppl Operative):245-9. doi: 10.1227/NEU.0b013e318214a809. PubMed PMID: 21368692.
56: Momani L, Al-Nuaimy W, Al-Jumaily M, Mallucci C. A mechatronic valve in the management of hydrocephalus: methods and performance. Med Biol Eng Comput. 2011 Jan;49(1):121-32. doi: 10.1007/s11517-010-0716-9. Epub 2010 Dec 21. PubMed PMID: 21174160.
57: Nakashima K, Oishi A, Itokawa H, Fujimoto M. [Effect of magnetic fields from home-use magnetic induction therapy apparatuses on adjustable cerebrospinal fluid shunt valves]. No Shinkei Geka. 2010 Aug;38(8):725-9. Japanese. PubMed PMID: 20697146.
58: Lemcke J, Meier U. Improved outcome in shunted iNPH with a combination of a Codman Hakim programmable valve and an Aesculap-Miethke ShuntAssistant. Cent Eur Neurosurg. 2010 Aug;71(3):113-6. doi: 10.1055/s-0029-1241179. Epub 2010 Apr 6. PubMed PMID: 20373276.
59: Kiefer M, Eymann R. Gravitational shunt complications after a five-year follow-up. Acta Neurochir Suppl. 2010;106:107-12. doi: 10.1007/978-3-211-98811-4_18. PubMed PMID: 19812930.
60: Kim KH, Yeo IS, Yi JS, Lee HJ, Yang JH, Lee IW. A pressure adjustment protocol for programmable valves. J Korean Neurosurg Soc. 2009 Oct;46(4):370-7. doi: 10.3340/jkns.2009.46.4.370. Epub 2009 Oct 31. PubMed PMID: 19893729; PubMed Central PMCID: PMC2773397.
61: Deininger MH, Weyerbrock A. Gravitational valves in supine patients with ventriculo-peritoneal shunts. Acta Neurochir (Wien). 2009 Jun;151(6):705-9; discussion 709. doi: 10.1007/s00701-009-0291-8. Epub 2009 Apr 1. PubMed PMID: 19337679.
62: Rohde V, Haberl EJ, Ludwig H, Thomale UW. First experiences with an adjustable gravitational valve in childhood hydrocephalus. J Neurosurg Pediatr. 2009 Feb;3(2):90-3. doi: 10.3171/2008.11.PEDS08154. PubMed PMID: 19278305.
63: Kaestner S, Kruschat T, Nitzsche N, Deinsberger W. Gravitational shunt units may cause under-drainage in bedridden patients. Acta Neurochir (Wien). 2009 Mar;151(3):217-21; discussion 221. doi: 10.1007/s00701-009-0215-7. Epub 2009 Feb 24. PubMed PMID: 19238319.
64: Kurzbuch AR, Momjian A, Nicoucar K, Momjian S. Extreme sensitivity of hearing to decreases of ICP in Menière's disease. Acta Neurochir (Wien). 2009 Aug;151(8):1005-8. doi: 10.1007/s00701-009-0196-6. Epub 2009 Feb 18. PubMed PMID: 19224119.
65: Eide PK, Sorteberg W. Changes in intracranial pulse pressure amplitudes after shunt implantation and adjustment of shunt valve opening pressure in normal pressure hydrocephalus. Acta Neurochir (Wien). 2008 Nov;150(11):1141-7; discussion 1147. doi: 10.1007/s00701-008-0138-8. Epub 2008 Oct 21. PubMed PMID: 18936877.
66: Zemack G, Romner B. Adjustable valves in normal-pressure hydrocephalus: a retrospective study of 218 patients. Neurosurgery. 2008 Feb;62 Suppl 2:677-87. doi: 10.1227/01.neu.0000316272.28209.af. PubMed PMID: 18596437.
67: Nadkarni TD, Rekate HL, Wallace D. Concurrent use of a lumboperitoneal shunt with programmable valve and ventricular access device in the treatment of pseudotumor cerebri: review of 40 cases. J Neurosurg Pediatr. 2008 Jul;2(1):19-24. doi: 10.3171/PED/2008/2/7/019. PubMed PMID: 18590390.
68: Hertel F, Züchner M, Decker C, Schill S, Bosniak I, Bettag M. The Miethke dual switch valve: experience in 169 adult patients with different kinds of hydrocephalus: an open field study. Minim Invasive Neurosurg. 2008 Jun;51(3):147-53. doi: 10.1055/s-2008-1065337. PubMed PMID: 18521785.
69: Yonekawa Y. [On the occasion of my retirement as head of the Neurochirurgische Universitätsklinik Zürich–changing aspects of treatment modality in modern neurosurgery and of neuroscience research. Presentation of our experience and historical backgrounds]. Brain Nerve. 2008 May;60(5):538-46. Review. Japanese. PubMed PMID: 18516976.
70: Sood S, Gilmer-Hill H, Ham SD. Management of lumbar shunt site swelling in children. J Neurosurg Pediatr. 2008 May;1(5):357-60. doi: 10.3171/PED/2008/1/5/357. PubMed PMID: 18447668.
71: Meier U, Lemcke J, Al-Zain F. Course of disease in patients with idiopathic normal pressure hydrocephalus (iNPH): a follow-up study 3, 4 and 5 years following shunt implantation. Acta Neurochir Suppl. 2008;102:125-7. PubMed PMID: 19388302.
72: Tsunoda A, Maruki C. Clinical experience with a dual switch valve (Miethke) for the management of adult hydrocephalus. Neurol Med Chir (Tokyo). 2007 Sep;47(9):403-8; discussion 408. PubMed PMID: 17895613.
73: Park SW, Yoon SH, Cho KH, Shin YS. Valve pressure upgrade may produce progressive deterioration of vision in children with slit ventricle syndrome. Pediatr Neurosurg. 2007;43(5):428-32. PubMed PMID: 17786014.
74: Kondageski C, Thompson D, Reynolds M, Hayward RD. Experience with the Strata valve in the management of shunt overdrainage. J Neurosurg. 2007 Feb;106(2 Suppl):95-102. PubMed PMID: 17330533.
75: Sato K, Shimizu S, Utsuki S, Suzuki S, Oka H, Fujii K. Disparity between adjusted and actual opening cerebrospinal fluid pressure in a patient with the Codman Hakim programmable valve: occult form of shunt failure due to head banging. Case report. J Neurosurg. 2006 Nov;105(5 Suppl):425-7. PubMed PMID: 17328269.
76: Miura M, Iijima N, Hayashida K, Kitazawa K, Ishii K, Ohara S. [Case of leptomeningeal carcinomatosis effectively treated with intrathecal chemotherapy using ventriculoperitoneal shunt]. Rinsho Shinkeigaku. 2006 Jun;46(6):404-9. Japanese. PubMed PMID: 16986702.
77: Chang CC, Kuwana N, Ito S. Management of patients with normal-pressure hydrocephalus by using lumboperitoneal shunt system with the Codman Hakim programmable valve. Neurosurg Focus. 1999 Oct 15;7(4):e8. PubMed PMID: 16918221.
78: Meier U, Lemcke J. Is it possible to optimize treatment of patients with idiopathic normal pressure hydrocephalus by implanting an adjustable Medos Hakim valve in combination with a Miethke shunt assistant? Acta Neurochir Suppl. 2006;96:381-5. PubMed PMID: 16671490.
79: Meier U, Lemcke J. Clinical outcome of patients with idiopathic normal pressure hydrocephalus three years after shunt implantation. Acta Neurochir Suppl. 2006;96:377-80. PubMed PMID: 16671489.
80: Meier U, Lemcke J. First clinical experiences in patients with idiopathic normal-pressure hydrocephalus with the adjustable gravity valve manufactured by Aesculap (proGAV(Aesculap)). Acta Neurochir Suppl. 2006;96:368-72. PubMed PMID: 16671487.
81: Meier U, Kiefer M, Neumann U, Lemcke J. On the optimal opening pressure of hydrostatic valves in cases of idiopathic normal-pressure hydrocephalus: a prospective randomized study with 123 patients. Acta Neurochir Suppl. 2006;96:358-63. PubMed PMID: 16671485.
82: Kiefer M, Meier U, Eymann R. Gravitational valves: relevant differences with different technical solutions to counteract hydrostatic pressure. Acta Neurochir Suppl. 2006;96:343-7. PubMed PMID: 16671482.
83: Agrawal D, Durity FA. Seizure as a manifestation of intracranial hypotension in a shunted patient. Pediatr Neurosurg. 2006;42(3):165-7. PubMed PMID: 16636618.
84: Arnell K, Eriksson E, Olsen L. The programmable adult Codman Hakim valve is useful even in very small children with hydrocephalus. A 7-year retrospective study with special focus on cost/benefit analysis. Eur J Pediatr Surg. 2006 Feb;16(1):1-7. PubMed PMID: 16544218.
85: Sprung C, Miethke C, Schlosser HG, Brock M. The enigma of underdrainage in shunting with hydrostatic valves and possible solutions. Acta Neurochir Suppl. 2005;95:229-35. PubMed PMID: 16463855.
86: Czosnyka ZH, Czosnyka M, Richards HK, Pickard JD. Evaluation of three new models of hydrocephalus shunts. Acta Neurochir Suppl. 2005;95:223-7. PubMed PMID: 16463854.
87: Bergsneider M, Black PM, Klinge P, Marmarou A, Relkin N. Surgical management of idiopathic normal-pressure hydrocephalus. Neurosurgery. 2005 Sep;57(3 Suppl):S29-39; discussion ii-v. Review. PubMed PMID: 16160427.
88: Kiefer M, Eymann R, Strowitzki M, Steudel WI. Gravitational shunts in longstanding overt ventriculomegaly in adults. Neurosurgery. 2005 Jul;57(1):109-19; discussion 109-19. PubMed PMID: 15987546.
89: Ringel F, Schramm J, Meyer B. Comparison of programmable shunt valves vs standard valves for communicating hydrocephalus of adults: a retrospective analysis of 407 patients. Surg Neurol. 2005 Jan;63(1):36-41; discussion 41. PubMed PMID: 15639519.
90: Schley D, Billingham J, Marchbanks RJ. A model of in-vivo hydrocephalus shunt dynamics for blockage and performance diagnostics. Math Med Biol. 2004 Dec;21(4):347-68. PubMed PMID: 15567889.
91: Bergsneider M, Yang I, Hu X, McArthur DL, Cook SW, Boscardin WJ. Relationship between valve opening pressure, body position, and intracranial pressure in normal pressure hydrocephalus: paradigm for selection of programmable valve pressure setting. Neurosurgery. 2004 Oct;55(4):851-8; discussion 858-9. PubMed PMID: 15458593.
92: Chopra I, Gnanalingham K, Pal D, Peterson D. A knot in the catheter–an unusual cause of ventriculo-peritoneal shunt blockage. Acta Neurochir (Wien). 2004 Sep;146(9):1055-6; discussion 1056-7. Epub 2004 Jun 28. PubMed PMID: 15340821.
93: Meier U. [Gravity valves for idiopathic normal pressure hydrocephalus. A Prospective study of 60 patients]. Nervenarzt. 2004 Jun;75(6):577-83. German. PubMed PMID: 15156286.
94: Katano H, Karasawa K, Sugiyama N, Yamashita N, Ohkura A, Kamiya K. Clinical evaluation of shunt implantations using Sophy programmable pressure valves: comparison with Codman-Hakim programmable valves. J Clin Neurosci. 2003 Sep;10(5):557-61. PubMed PMID: 12948459.
95: Pang Q, Wang C, Hu Y, Xu G, Zhang L, Hao X, Zhang Q, Gregerson H. Experimental study of the morphology of cerebral bridging vein. Chin Med Sci J. 2001 Mar;16(1):19-22. PubMed PMID: 12899343.
96: Rizk T, Abi Lahoud G, Hourany R, Jabbour P, Samaha E, Nohra G, Moussa R, Okais N. [Adjustable shunt system for the treatment of intracranial cerebrospinal fluid collections. Analysis of a series of 50 cases]. J Med Liban. 2002 Jan-Apr;50(1-2):14-6. French. PubMed PMID: 12841307.
97: Lundkvist B, Eklund A, Koskinen LO, Malm J. An adjustable CSF shunt: advices for clinical use. Acta Neurol Scand. 2003 Jul;108(1):38-42. PubMed PMID: 12807391.
98: Zemack G, Bellner J, Siesjö P, Strömblad LG, Romner B. Clinical experience with the use of a shunt with an adjustable valve in children with hydrocephalus. J Neurosurg. 2003 Mar;98(3):471-6. PubMed PMID: 12650416.
99: Rohde V, Weinzierl M, Mayfrank L, Gilsbach JM. Postshunt insertion Cerebrospinal fluid fistulas in infants treated by an adjustable valve opening pressure reduction. Childs Nerv Syst. 2002 Dec;18(12):702-4. Epub 2002 Aug 24. PubMed PMID: 12483354.
100: Zemack G, Romner B. Adjustable valves in normal-pressure hydrocephalus: a retrospective study of 218 patients. Neurosurgery. 2002 Dec;51(6):1392-400; discussion 1400-2. PubMed PMID: 12445344.
101: Robinson S, Kaufman BA, Park TS. Outcome analysis of initial neonatal shunts: does the valve make a difference? Pediatr Neurosurg. 2002 Dec;37(6):287-94. PubMed PMID: 12422042.
102: Baird C, Farner S, Mohr C, Pittman T. The effects of protein, red blood cells and whole blood on PS valve function. Pediatr Neurosurg. 2002 Oct;37(4):186-93. PubMed PMID: 12372911.
103: Meier U, Kintzel D. Clinical experiences with different valve systems in patients with normal-pressure hydrocephalus: evaluation of the Miethke dual-switch valve. Childs Nerv Syst. 2002 Jul;18(6-7):288-94. Epub 2002 May 15. PubMed PMID: 12172931.
104: Muramatsu H, Koike K, Teramoto A. Ventriculoperitoneal shunt dysfunction during rehabilitation: prevalence and countermeasures. Am J Phys Med Rehabil. 2002 Aug;81(8):571-8. PubMed PMID: 12172065.
105: Cook SW, Bergsneider M. Why valve opening pressure plays a relatively minor role in the postural ICP response to ventricular shunts in normal pressure hydrocephalus: modeling and implications. Acta Neurochir Suppl. 2002;81:15-7. PubMed PMID: 12168289.
106: Hidaka M, Matsumae M, Ito K, Tsugane R, Suzuki Y. Dynamic measurement of the flow rate in cerebrospinal fluid shunts in hydrocephalic patients. Eur J Nucl Med. 2001 Jul;28(7):888-93. PubMed PMID: 11504085.
107: Zemack G, Romner B. Do adjustable shunt valves pressure our budget? A retrospective analysis of 541 implanted Codman Hakim programmable valves. Br J Neurosurg. 2001 Jun;15(3):221-7. PubMed PMID: 11478056.
108: Kay AD, Fisher AJ, O'Kane C, Richards HK, Pickard JD; United Kingdom and Ireland Medos Shunt Audit Group. A clinical audit of the Hakim programmable valve in patients with complex hydrocephalus. Br J Neurosurg. 2000 Dec;14(6):535-42. PubMed PMID: 11272031.
109: Schuhmann MU, Engel M, Runge L, Samii M, Brinker T. Application of clinically recorded ICP patterns–an extension of conventional shunt testing. Childs Nerv Syst. 2000 Dec;16(12):856-61. PubMed PMID: 11156301.
110: Zemack G, Romner B. Seven years of clinical experience with the programmable Codman Hakim valve: a retrospective study of 583 patients. J Neurosurg. 2000 Jun;92(6):941-8. PubMed PMID: 10839253.
111: Bret P, Guyotat J, Ricci AC, Mottolese C, Jouanneau E. [Clinical experience with the Sp[hy adjustable valve in the treatment of adult hydrocephalus. A series of 147 cases]. Neurochirurgie. 1999 May;45(2):98-108; discussion 108-9. French. PubMed PMID: 10448649.
112: Yamashita N, Kamiya K, Yamada K. Experience with a programmable valve shunt system. J Neurosurg. 1999 Jul;91(1):26-31. PubMed PMID: 10389876.
113: Rohde V, Mayfrank L, Ramakers VT, Gilsbach JM. Four-year experience with the routine use of the programmable Hakim valve in the management of children with hydrocephalus. Acta Neurochir (Wien). 1998;140(11):1127-34. PubMed PMID: 9870057.
114: Tsuji O, Sato K. CSF dynamics in a patient with a programmable shunt. Acta Neurochir Suppl. 1998;71:364-7. PubMed PMID: 9779231.
115: Munshi I, Lathrop D, Madsen JR, Frim DM. Intraventricular pressure dynamics in patients with ventriculopleural shunts: a telemetric study. Pediatr Neurosurg. 1998 Feb;28(2):67-9. PubMed PMID: 9693334.
116: Czosnyka Z, Czosnyka M, Richards HK, Pickard JD. Posture-related overdrainage: comparison of the performance of 10 hydrocephalus shunts in vitro. Neurosurgery. 1998 Feb;42(2):327-33; discussion 333-4. PubMed PMID: 9482183.
117: Ortler M, Kostron H, Felber S. Transcutaneous pressure-adjustable valves and magnetic resonance imaging: an ex vivo examination of the Codman-Medos programmable valve and the Sophy adjustable pressure valve. Neurosurgery. 1997 May;40(5):1050-7; discussion 1057-8. PubMed PMID: 9149264.
118: Brydon HL, Bayston R, Hayward R, Harkness W. Removed shunt valves: reasons for failure and implications for valve design. Br J Neurosurg. 1996 Jun;10(3):245-51. PubMed PMID: 8799534.
119: Brydon HL, Bayston R, Hayward R, Harkness W. The effect of protein and blood cells on the flow-pressure characteristics of shunts. Neurosurgery. 1996 Mar;38(3):498-504; discussion 505. PubMed PMID: 8837802.
120: Luxton G, Yu C, Petrovich Z, Zelman V, Zee CS, Machovec DJ, LeMay D, Apuzzo ML. Mechanical malfunction of the Leksell Gamma knife during patient treatment. Stereotact Funct Neurosurg. 1996;66(1-3):35-40. PubMed PMID: 8938931.
121: Malm J, Kristensen B, Fagerlund M, Koskinen LO, Ekstedt J. Cerebrospinal fluid shunt dynamics in patients with idiopathic adult hydrocephalus syndrome. J Neurol Neurosurg Psychiatry. 1995 Jun;58(6):715-23. PubMed PMID: 7608674; PubMed Central PMCID: PMC1073553.
122: Trost HA. Is there a reasonable differential indication for different hydrocephalus shunt systems? Childs Nerv Syst. 1995 Apr;11(4):189-92. PubMed PMID: 7621478.
123: Clyde BL, Albright AL. Evidence for a patent fibrous tract in fractured, outgrown, or disconnected ventriculoperitoneal shunts. Pediatr Neurosurg. 1995;23(1):20-5. PubMed PMID: 7495662.
124: Hafez MA, Kempski O. A nonlinear biomechanical model for evaluation of cerebrospinal fluid shunt systems. Childs Nerv Syst. 1994 Jul;10(5):302-10; discussion 310-1. PubMed PMID: 7954499.
125: Norbash AM, Pelc NJ, Shimakawa A, Enzmann DR. Shunt flow measurement and evaluation of valve oscillation with a spin-echo phase-contrast MR sequence. Radiology. 1994 Feb;190(2):560-4. PubMed PMID: 8284416.
126: Sood S, Kim S, Ham SD, Canady AI, Greninger N. Useful components of the shunt tap test for evaluation of shunt malfunction. Childs Nerv Syst. 1993 Jun;9(3):157-61; discussion 162. PubMed PMID: 8374920.
127: Sindou M, Guyotat-Pelissou I, Chidiac A, Goutelle A. Transcutaneous pressure adjustable valve for the treatment of hydrocephalus and arachnoid cysts in adults. Experiences with 75 cases. Acta Neurochir (Wien). 1993;121(3-4):135-9. PubMed PMID: 8512009.
128: Ohkuma H, Shinozaki N, Ogane K, Suzuki N, Ebina K, Suzuki S. [Two cases of failure of a programmable pressure valve]. No Shinkei Geka. 1992 Nov;20(11):1205-10. Japanese. PubMed PMID: 1448197.
129: Larsson A, Jensen C, Bilting M, Ekholm S, Stephensen H, Wikkelsö C. Does the shunt opening pressure influence the effect of shunt surgery in normal pressure hydrocephalus? Acta Neurochir (Wien). 1992;117(1-2):15-22. PubMed PMID: 1514424.
130: Chidiac A, Pelissou-Guyotat I, Sindou M. [Practical value of transcutaneous pressure adjustable valves (Sophy SU 8) in the treatment of hydrocephalus and arachnoid cysts in adults (75 cases)]. Neurochirurgie. 1992;38(5):291-6. French. PubMed PMID: 1299774.
131: Nash TP. Venous ulceration: factors influencing recurrence after standard surgical procedures. Med J Aust. 1991 Jan 7;154(1):48-50. PubMed PMID: 1984586.
132: Choudhury AR. Avoidable factors that contribute to the complications of ventriculoperitoneal shunt in childhood hydrocephalus. Childs Nerv Syst. 1990 Sep;6(6):346-9. PubMed PMID: 2257549.
133: Lumenta CB, Roosen N, Dietrich U. Clinical experience with a pressure-adjustable valve SOPHY in the management of hydrocephalus. Childs Nerv Syst. 1990 Aug;6(5):270-4. PubMed PMID: 2224877.
134: Horton D, Pollay M. Fluid flow performance of a new siphon-control device for ventricular shunts. J Neurosurg. 1990 Jun;72(6):926-32. PubMed PMID: 2338577.
135: Serlo W, Saukkonen AL, Heikkinen E, von Wendt L. The incidence and management of the slit ventricle syndrome. Acta Neurochir (Wien). 1989;99(3-4):113-6. PubMed PMID: 2773680.
136: Wocjan J, Roszkowski M, Sliwka S, Batorski L, Pawłowski G. Analysis of CSF dynamics by computerized pressure-elastance resorption test in hydrocephalic children. Indications for surgery. Childs Nerv Syst. 1986;2(2):98-100. PubMed PMID: 3731175.
137: Lew WY, Chen ZY, Guth B, Covell JW. Mechanisms of augmented segment shortening in nonischemic areas during acute ischemia of the canine left ventricle. Circ Res. 1985 Mar;56(3):351-8. PubMed PMID: 3971509.
138: Noetzel MJ, Baker RP. Shunt fluid examination: risks and benefits in the evaluation of shunt malfunction and infection. J Neurosurg. 1984 Aug;61(2):328-32. PubMed PMID: 6737057.
139: Watts C, Keith HD. Testing the hydrocephalus shunt valve. Childs Brain. 1983;10(4):217-28. PubMed PMID: 6884124.
140: Kuurne T, Servo A, Porras M. Subdural effusions re-appearing after shunts in patients with non-tumoural stenosis of the aqueduct. Acta Neurochir (Wien). 1983;67(1-2):127-34. PubMed PMID: 6837342.
141: Chazal J, Janny P, Irthum B, Massini B. [Slit-ventricle. Apropos of 2 cases]. Neurochirurgie. 1983;29(5):327-31. French. PubMed PMID: 6607421.
142: Walsh JW, James HE. Subtemporal craniectomy and elevation of shunt valve opening pressure in the management of small ventricle-induced cerebrospinal fluid shunt dysfunction. Neurosurgery. 1982 Jun;10(6 Pt 1):698-703. PubMed PMID: 7110543.
143: Baldini M, Princi L, Vivenza C. Subdural hematoma secondary to CSF ventricular shunt. Schweiz Arch Neurol Neurochir Psychiatr. 1980;127(1):5-14. PubMed PMID: 7444404.
144: Tansy MF, Salkin LM, Innes DL, Martin JS, Landin WE, Kendall FM. The occlusive competence of the duodenal orifice of the canine pancreatic duct. Surg Gynecol Obstet. 1977 Jun;144(6):865-8. PubMed PMID: 870997.
145: Voth D, Nakayama N. [A new valve controlled system for ventricular drainage. (Technical description and clinical results)]. Neurochirurgia (Stuttg). 1976 Sep;19(5):196-201. German. PubMed PMID: 1086439.