American Society for Peripheral Nerve
ASPN Home ASPN Home Past & Future Meetings Past & Future Meetings

Back to 2023 Abstracts


The Dermal Sensory Regenerative Peripheral Nerve Interface (DS-RPNI) For Re-establishing Multimodal Sensory Feedback in Peripheral Afferents
Widya Adidharma, MD1; Jennifer C Lee, MSE2; Amir Dehdashtian, MD, MPH2; Paul S. Cederna, MD3; Stephen WP Kemp, PhD2
1University of Michigan, Ann Arbor, WA; 2University of Michigan, Ann Arbor, MI; 3Department of Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI

INTRODUCTION Without meaningful and intuitive sensory feedback, even the most advanced prosthetics require significant cognitive burden to operate given the inability to feel what the prosthetic touches, to modulate motor actions, and to understand the limbís position in space. This leads to failure of prosthetic embodiment and prosthetic abandonment. A major challenge in facilitating prosthetic sensory feedback is the lack of a stable patient-prosthetic sensory neural interface. Current interfaces are limited by unnatural or painful sensations, modality mismatch, instability, and variable somatotopic organization. Our lab developed the Dermal Sensory Regenerative Peripheral Nerve Interface (DS-RPNI), a construct composed of de-epithelialized dermal grafts wrapped around transected sensory peripheral nerves, as a novel biologic sensory nerve interface. We hypothesize that physiologic reinnervation of various end organ sensory targets in DS-RPNI by transected peripheral afferents will facilitate sensory neural signaling following application of various sensory stimuli to DS-RPNI.
METHODS Eighteen rats underwent sural nerve transection with subsequent implantation into either acellular dermal matrix (ADM, negative control group that lacks end organ targets for reinnervation) or de-epithelialized dermal graft from a donor rat hindpaw (DS-RPNI group). After a 3-month maturation period, compound sensory nerve action potentials (CSNAPs) were recorded during construct exposure to light touch (monofilament), vibration (tuning fork), heat (60oC water), cold (ice water), and nociceptive (capsaicin) sensory modalities. Only one modality was tested at a time with 5-minute intertrial intervals. Statistical analyses compared the DS-RPNI and negative control groups.
RESULTS Three months after implantation, DS-RPNIs were viable and well-vascularized. Fine touch of DS-RPNI evoked CSNAPs of increasing waveform amplitudes with increasing monofilament size. Increasing vibration frequency applied to DS-RPNI evoked CSNAPs with decreasing waveform amplitudes. The CSNAPs elicited were significantly larger in the DS-RPNI group compared to the ADM group with vibration frequencies of 256 and 426 Hz (p=0.02 and p=0.04, respectively), 10g and 26g monofilament fine touch (p=0.006 and p=0.02, respectively), cold (p=0.04), and heat (p=0.03). There was no significant difference with nociceptive stimuli (p=0.78).
CONCLUSIONS The significantly larger CSNAPs recorded from the DS-RPNI group compared to the negative control suggests that the DS-RPNI response is most likely due to functional reinnervation rather than direct nerve stimulation. The results of this study demonstrate the potential of the DS-RPNI as a multi-modality sensory peripheral nerve interface, potentially revolutionizing the frontier of prosthetic sensory feedback. Future directions will focus on understanding the DS-RPNI immunohistological composition that contributes to its success as a neural interface


Back to 2023 Abstracts