Impact of direct epispinal stimulation on bladder and bowel functions in pigs: A feasibility study

Abstract

Aims: This study assesses the potential of epispinal (subdural) stimulation application in the treatment of urinary and bowel neurological disorders. Acute experiments were performed on a large animal model -the domestic pig -to develop a new methodology facilitating future results and technology transfers to human.

The Role of Functional Neuroanatomy of the Lumbar Spinal Cord in Effect of Epidural Stimulation

“…Using increasing stimulation frequencies and vibration of the Achilles tendon could be used in future experiments to evaluate the changes of MR amplitude as describe in rodents (Lavrov et al, 2006 ). Overall, our results show the feasibility of the swine as an intermediary model to study EES evoked motor responses in SCI models and could be combined in the investigation of autonomic functions as showed recently by Guiho et al ( 2017 ).…”

“…Another important aspect of the swine model that has to be considered is the weight (size) of the animals as conventional breeds can reach more than 100 kg typically at 4 months. In this study we used swine with similar weight (25–40 kg) as reported in articles describing vertebral morphometry (Bozkus et al, 2005 ; Busscher et al, 2010 ), SCI model (Lee et al, 2013 ), feasibility of EES as a restorative paradigms (Hachmann et al, 2013 ; Guiho et al, 2017 ) and stereotactic-guided micro stimulation (Grahn et al, 2016 ). For chronic experiments with EES, minipigs breeds might be considered as an option in terms of their growth and handling.…”

“…In some models angles of rostral and caudal roots from 0 to 45° in respect to the transverse plane were incorporated, (Struijk et al, 1993 ; Lempka et al, 2015 ), however without natural variation from segment to segment that makes knowledge about each segment anatomy critical for neuromodulation strategies. The anatomical description of the dorsal anatomy of the spinal cord provided here, could be used for development of computational simulations and contribute to future spinal cord neuromodulation studies, the effect of EES on bladder and bowel functions (for example, see Guiho et al, 2017 ), as well as long term therapeutic effect for SCI. Also, considering the advantages of the swine model over rodents in terms of size and similarities with humans in relation to spinal anatomy, the delivery of orientation-selective EES could be achieved taking into account the differences in neuroanatomy across different spinal cord segments (Figures 1 , 2 , Tables 1 – 4 ) and considering the importance of electrode position in relation to the dorsal roots (Figures 6 , 7 ).…”

“…Small animal models, such as the rodent, are not optimal for studying these structures due to significant difference in spinal cord anatomy between human and rodent spinal cord anatomy (Shah and Lavrov, 2017 ). Large animals including calf (Cotterill et al, 1986 ), sheep (Wilke et al, 1997 ; Kandziora et al, 2001 ) and swine (Bozkus et al, 2005 ; Navarro et al, 2012 ; Zurita et al, 2012 ; Hachmann et al, 2013 ; Lee et al, 2013 ; Guiho et al, 2017 ), have been successfully used as translational models. Particularly, the swine spine has gained attention as a suitable model due to its similarity to humans in terms of vertebral morphometry (McLain et al, 2002 ; Busscher et al, 2010 ; Sheng et al, 2016 ) and biomechanical properties (Yingling et al, 1999 ; Sheng et al, 2010 ); however, a description of the swine spinal cord anatomy and its intersegmental relationship with the spine is missing.…”

“…Particularly, the swine spine has gained attention as a suitable model due to its similarity to humans in terms of vertebral morphometry (McLain et al, 2002 ; Busscher et al, 2010 ; Sheng et al, 2016 ) and biomechanical properties (Yingling et al, 1999 ; Sheng et al, 2010 ); however, a description of the swine spinal cord anatomy and its intersegmental relationship with the spine is missing. In this study we chose the swine model due to its translational relevance (Bozkus et al, 2005 ; Zurita et al, 2012 ; Hachmann et al, 2013 ; Lee et al, 2013 ; Guiho et al, 2017 ; Toossi et al, 2017 ) and its emergence as an optimal model to study EES following SCI (Schomberg et al, 2017 ).…”