In Vivo CSF Shunt Hydrodynamics in Hydrocephalus

描述(由申请人提供)：由于诊断的不确定性和高治疗风险，常压性脑积水(NPH)的管理是具有挑战性的。到目前为止，还没有针对这种疾病的循证治疗指南。我们的长期目标是通过降低与分流阀相关的并发症和增加我们对不同分流设计如何影响脑脊液(CSF)流体动力学的了解来改善NPH的预后。本研究采用三层共享受试者研究设计。其具体目的是1)确定两种可调瓣设计中，一种带有虹吸控制装置和一种没有虹吸控制装置，在降低并发症方面对于NPH的治疗更好，2)比较标准差压阀在有和没有虹吸控制装置治疗NPH时的颅内压(ICP)生理反应，以及3)确定分流手术前后测量的颅内血液/流体动力学参数是否支持颅内压动力学的调谐动态吸收模型。我们假设虹吸控制装置会增加分流管引流不足的发生率，表现为缺乏神经功能改善和脑室大小缩小。此外，我们假设现有的脑积水模型过于简单化，而分流诱发的水动力学模型更好地基于ICP波形特征和新的动力学模型的应用。所有研究都将作为评估两个现有的FDA批准的可调式瓣膜的前瞻性随机临床试验的一部分进行。结果分析将对希望在NPH管理中应用循证指南的临床医生有用。从更好地了解脑脊液分流术的颅内压生理的角度来看，全面的流体动力学研究将提供有价值的信息，这些信息将有助于为个别患者选择最佳的瓣膜压力或类型。此外，我们预计分流阀制造商将利用这些信息来改进当前的阀门设计。记录调谐动态吸收模型的确凿证据可能会对所有的颅内压紊乱有根本的影响。

DESCRIPTION (provided by applicant): The management of normal pressure hydrocephalus (NPH) is challenging due to diagnostic uncertainties and high treatment risks. To date, there are no evidence-based treatment guidelines for this disorder. Our long-term goal is to improve the outcome of NPH by lowering complications related to shunt valves and by increasing our understanding of how different shunt designs influence cerebrospinal fluid (CSF) hydrodynamics. This investigation uses a three-tiered shared-subject study design. The Specific Aims are to 1) determine which of two adjustable valve designs, one with a siphon control device and one without, is superior for the treatment of NPH with regard to lowering the complication rate, 2) compare the intracranial pressure (ICP) physiological response of a standard differential pressure valve, with and without a siphon control device, in the treatment of NPH, and 3) determine whether intracranial hemo/hydrodynamic variables, measured before and after a shunt operation, support the tuned-dynamic absorber model, of intracranial pressure dynamics. We hypothesize that siphon control devices increase the incidence of shunt under-drainage, manifesting as a lack of both neurological improvement and ventricular size reduction. Furthermore, we hypothesize that current hydrocephalus models are over- simplistic and that shunt-induced hydrodynamics are better modeled based on ICP waveform characteristics and the application of novel dynamic models. All of the studies will be performed as part of a prospective, randomized clinical trial assessing two existing, FDA-approved, adjustable valves. The outcome analysis will be useful for clinicians wishing to apply evidence-based guidelines in the management of NPH. From a viewpoint of better understanding the ICP physiology of CSF shunts, the comprehensive hydrodynamic studies will provide valuable information that will be useful in selecting the optimal valve pressure or type for individual patients. In addition, we foresee the information being used by shunt valve manufacturers to improve current valve designs. Documenting definitive evidence of the tuned-dynamic absorber model could have fundamental implications to all ICP disorders.