Ureteral Stent Electromagnetic Removal (USER) Device for Pediatric Patients

Fannin Partners, Llc, Houston TX

Investigators

Abstract

PROJECT SUMMARY Significance: Over 5,000 children have ureteral stents placed each year to alleviate an obstruction caused by a kidney stone between the kidney and the bladder or to maintain urinary flow following reconstructive or transplant surgery. In adults, a dangler string that is threaded through the urethra and secured to the skin is simply pulled at a follow up visit to remove the stent, but this string is removed in children to prevent infection and accidental removal. Children must then undergo an invasive procedure via cystoscopy, which consists of inserting a scope into the urethra under general anesthesia to pull the stent out. Recent evidence suggests early overexposure to anesthesia has been associated with an increased risk of long-term cognitive deficits in language and abstract reasoning. As such, medical solutions that can provide the same results as traditional procedures without general anesthesia are being sought out in all areas of medicine, but particularly in pediatrics. Innovation: The Ureteral Stent Electromagnetic Removal (USER) device is a non-invasive stent removal system that uses a magnetic bead and an external electromagnet to smoothly guide the stent out of the patient's body without the need for general anesthesia. The magnetic bead is coated in a biocompatible material and is secured to the lower stent curl by tying the bead to the dangler string and cutting it short so that the bead and string remain in the patient's bladder. The electromagnet is held in a patient-friendly casing with smooth surfaces and handles for ease of manipulation. This solution shortens the removal process, reduces the cost of the procedure and minimizes the risk of cognitive deficits in children from early overexposure to general anesthesia. Approach: In this SBIR Phase I project, Fannin Innovation Studio will optimize the prototype device design and test it in benchtop, animal, and cadaver models of the urinary tract. The Specific Aims of this project are: (1) Build and characterize a prototype USER device including magnetic beads and electromagnet with adjustable field strength. The performance of various magnet geometries, materials, and coatings will be characterized and implemented into the prototype. The field geometries of the electromagnet will then be evaluated and a user interface to control the magnetic field strength will be built. (2) Test the prototype USER device in benchtop, animal, and cadaver urinary tract models. The previous benchtop model will be refined to be more anatomically representative of the pediatric urinary tract with respect to material elasticity and surface characteristics. The prototype will then be tested in porcine and cadaver models to assess for signs of tissue damage and further demonstrate the feasibility of the device in living tissue. We believe that the USER device will bring value to pediatric patients, providers, and children's hospitals by providing a solution for stent removal that reduces the use of costly OR resources, shortens surgeon procedure time, and eliminates the risk of cognitive deficits from overexposure to anesthesia in children.