SUFU 2022: A 3D Digital Map of the Human Saphenous Nerve: A Neuroanatomical Approach to Developing A Novel Neuromodulation Therapy for Treating Overactive Bladder

( Saphenous nerve (SAFN) stimulation is an emerging treatment for overactive bladder (OAB) syndrome, but precise knowledge of the subcutaneous distribution of nerve branches is lacking. This study volumetrically documented and modeled in 3D the course of branches of the SAFN relative to bony/soft tissue landmarks.

The SN and its branches along with bony and soft tissue landmarks were serially dissected, digitized (MicroScribe® G2X), and laser scanned (FARO® Quantum FaroArm®) in 10 embalmed lower limb specimens. The digitized and laser scanned data were registered and modelled (Autodesk® Maya®) with plug-inns developed in the Univ Toronto laboratory. The 3D models were constructed using clinically identifiable landmarks (e.g., tibial tuberosity and medial malleolus) with the intent of subsequently converting the digital maps into computational models.

The SAFN has an extensive subcutaneous network comprised of the infrapatellar and medial crural cutaneous branches (MCC).

  • MCC consist of an anterior (AB) and posterior (PB) branch, which further ramify to supply the medial aspect of the leg.
  • AB divides into multiple smaller branches as it courses distally deep to the great saphenous vein to the foot. Superiorly, the AB lies just posterior to the medial border of the tibia and inferiorly, on its medial surface.
  • PB lies on the crural fascia superficial to the medial head of gastrocnemius and terminates superior to the ankle. Absence of PB and variations in branching pattern were found.

The novel 3D data is the first cartesian coordinate-based map of the MCC nerve branches in the human lower leg. We predict this high-fidelity data will facilitate more accurate computational (finite element) modeling of peripheral nerve stimulation modalities (e.g., non-invasive, percutaneous or implantable device) and provide the necessary detail to translate these findings to the clinical setting.


Funding: MITACS Accelerate Fellowship 

Authors: Michael Peng1, Paul Yoo2, Anne Agur1
1. Dept. of Surgery, University of Toronto, Toronto, ON, Canada, 
2. Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada

Written by:  Diane K. Newman, DNP, ANP-BC, FAAN is an Adjunct Professor of Urology in Surgery, Perelman School of Medicine, University of Pennsylvania and Co-Director of the Penn Center for Continence and Pelvic Health.