Evaluation of inflammation and morphometric parameters associated with neural device implantation in the sciatic nerve

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Publication Type dissertation
School or College College of Engineering
Department Biomedical Engineering
Author Christensen, Michael Benjamin
Title Evaluation of inflammation and morphometric parameters associated with neural device implantation in the sciatic nerve
Date 2011-05
Description Peripheral nerve electrodes offer the potential to record and stimulate nerve fibers for the control of neuroprosthetic devices or for functional electrical stimulation. For example, nerve cuff electrodes have been successfully used in clinical applications such as sacral nerve stimulation for the treatment of bladder incontinence and peroneal nerve stimulation for the treatment of foot drop. While nerve cuff electrodes function in these applications where broad stimulation of the nerve is suitable, specific recording and stimulation of small groups of nerve fibers is only possible through the use of more invasive electrodes. However, such electrodes elicit a foreign body response which can include the recruitment of macrophages to the device interface and changes in morphometric parameters in the implanted nerve which could negatively affect the performance of the electrodes. Here, we investigated the foreign body response to chronically implanted axially penetrating arrays and their associated encapsulation cuffs, as well as encapsulating cuffs in the absence of a penetrating array, in sciatic nerve. Additionally, we investigated the validity of the commonly used method of using the contralateral nerve as an internal control to an ipsilateral procedure. We found that the implantation of axially penetrating arrays and their associated cuffs elicits an inflammatory reaction, including the recruitment of macrophages to the electrode and cuff interfaces, which is accompanied by morphometric changes in the implanted nerve, similar to other penetrating arrays. Additionally, we found that the implantation of nerve cuffs alone elicited a similar reaction which was exacerbated when using an open mesh design. These studies establish a baseline measurement of the inflammatory response to axially penetrating arrays and their associated cuffs which can be used when considering future designs. These studies also suggest that the role of encapsulating cuffs in the inflammatory response to devices which contain both a cuff and a penetrating electrode needs to be further elucidated. We also found that naturally occurring difference in morphometric parameters do exists based on nerve location, and that ipsilateral procedures can cause changes in contralateral morphometric parameters compared with naïve controls, suggesting that the use of contralateral nerves as internal controls is inappropriate.
Type Text
Publisher University of Utah
Subject Morphometric; Nerve cuff; Peripheral nerve; Sciatic nerve; Foreign-body reaction; Foreign body response; Neuroprostheses; Neural device implantation; Electrode arrays; Biomedical engineering
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Rights Management (c) Michael Benjamin Christensen
Format Medium application/pdf
Format Extent 28,178,921 bytes
Identifier us-etd3,23685
Source Original housed in Marriott Library Special Collections, RD14.5 2011 .C47
ARK ark:/87278/s6m62127
Setname ir_etd
ID 194746
Reference URL https://collections.lib.utah.edu/ark:/87278/s6m62127