CASIT

Developing and Testing Thin Film Nitinol Low-Profile Devices for use in Vascular Repair

Rapid and minimally invasive controls are needed to prevent excessive hemorrhaging from major arteries in wounded soldiers on the battlefield or in civilians appearing at urgent care facilities with significant trauma. The focus of this research is to develop an ultra-low profile device containing new thin film Nitinol to occlude the damaged vessels preventing excessive blood loss as well as subsequent repair.

Nitinol (NiTi) is an excellent biocompatible, equiatomic alloy with many desirable attributes ideal for vascular repair. Bulk Nitinol has been used in transcatheter applications in many currently available medical devices. For example bulk Nitinol, is currently used in stents, ASD closure devices, and vena cava filters. Therefore, bulk Nitinol has a long track record of successful use in the vascular system. However, the delivery systems for bulk Nitinol are relatively large compared to thin film due to the material's physical dimensions. The size limits bulk Nitinol's applications in many trauma situations. That is bulk Nitinol is an order of magnitude larger than thin film Nitinol (i.e. less than 1/5th the diameter of a human hair), i.e. thin film is a membrane which is ideal for patching vascular damage or occluding blood flow. The thin film Nitinol also dramatically reduces catheter sizes while presenting an ideal opportunity to develop new ultra-low profile vascular repair devices.

Figure 1 : Picture of bulk Nitinol stent, bulk Nitinol ASD closure device, and bulk Nitinol vena cava filter used in current medical procedures.
Figure 1 : Picture of bulk Nitinol stent, bulk Nitinol ASD closure device, and bulk Nitinol vena cava filter used in current medical procedures.

During the last two years UCLA has studied the use of thin film Nitinol in several related devices, including heart valves and covered stents. Figure 2 shows video clips of the heart valve in operation and the deployment of a covered stent in a flow loop. The work at CASIT builds upon these advancements to develop several new ultra-low profile vascular repair devices

Funding for this work is provided by the Telemedicine and Advanced Technology Research Center (TATRC) and the Department of Defense (DoD)

Figure 2 : Picture of thin film Nitinol heart valve (figure left) and thin film Nitinol covered stent (right) developed and built at UCLA.
Figure 2 : Picture of thin film Nitinol heart valve (figure left) and thin film Nitinol covered stent (right) developed and built at UCLA.

Investigators

Greg Carman (Professor Mechanical and Aerospace Engineering)
David Rigberg (Vascular Surgeon)f
Dan Levi (Pediatric Cardiologist)
Allan W. Tulloch (MD in vascular surgery)
Colin P. Kealey (MD in vascular surgery)
Youngjae Chun (PhD, postdoc in Dept. of Mechanical Engineering)
Hsin-yun Chang (MS, graduate student in Dept. of Mechanical Engineering)
Steve Lin (PhD student in IDP of Biomedical Engineering)

Publications in Peer-reviewed Journals:

  1. Levi D.S., Kealey C.P., Chun Y.J., Tulloch A.W., Mohanchandra K.P., Carman G.P., Fernando
    Vinuela, and Rigberg D.A. A Novel, Hyperelastic Thin Film Nitinol Neurovascular Flow Diversion
    Stent.     Journal of Neuroradiology, submitted for review.
  2. Youngjae Chun, Soojung C. Hur, Colin P. Kealey, Daniel S. Levi, K.P. Mohanchandra, Jeff D.
    Eldredge, Fernando Vinuela, Dino Di Carlo, and Gregory P. Carman. Intra-Aneurysmal Flow
    Reductions in a Thin Film Nitinol Flow Diverter.     Smart Materials and Structures, submitted for
    review.
  3. KP Mohanchandra, Youngjae Chun, Sergey Prikhodko, and Gregory P. Carman. TEM
    Characterization of super-hydrophilic Ni-Ti Thin Film.     Materials Letters, In press.
  4. Kealey C.P., Whelan S.A., Chun Y.J., Hur C.S, Tulloch A.W., Mohanchandra K.P., DiCarlo D., Levi
    D.S., Carman G.P., and Rigberg D.A. An In Vitro Examination of the Hemocompatibility Profile of
    Thin Film Nickel Titanium Using Whole Blood under Stenotic Flow Conditions.     Biomaterials, Vol.
    31 (34), pp.8864-8871.
  5. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Michael C. Fishbein, and Greg P. Carman.
    Novel Micro-Pattering Processes for Thin Film NiTi Vascular Devices. Smart Materials and
    Structures, 19(105021), pp.1-9.
  6. Kealey CP. Whelan SA, Chun YJ, Soojung CH, Tulloch AW, Mohanchandra KP, Di Carlo D, Levi DS, Carman GP,Rigberg DA. "In vitro hemocompatibility of thin film nitinol in stenotic flow conditions." Biomaterials, 2010.
  7. Allan W Tulloch, Youngjae Chun, Daniel S Levi, Kotekar P Mohanchandra, Gregory P Carman, Peter F Lawrence, David A Rigberg. "Hydrophilic Surface Treatment of Thin Film Nickel Titanium Reduces Platelet Adhesion and Aggregation in vitro and Prevents Endograft Thrombosis in vivo," Journal of Surgical Research, 2010.
  8. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Fernando Vinuela, and Greg P. Carman. "Superhydrophilic Surface Treatment for Thin film NiTi Vascular Applications." Journal of Biomedical Materials C, 2009, S0928-4931(09) 00199-4, pp.1-6.
  9. David Rigberg,Allan Tulloch,Youngjae Chun, Kotekar Panduranga Mohanchandra, Greg P. Carman, and Peter Lawrence. "Thin-film nitinol (NiTi): A feasibility study for a novel aortic stent graft material." Journal of Vascular Surgery, 2009; 50, pp.375-380.
  10. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Fernando Vinuela, Fernando Vinuela, Jr. and Greg P. Carman. "Thin Film Nitinol Microstent for Aneurysm Occlusion." Journal of Biomechanical Engineering - ASME Trans. Vol. 131, 2009,   pp.1-8. (Figures were highlighted on the cover page of the journal.)
  11. Levi DS, DeConde AS, Stepan L, Moore JW, "Use of a covered stent modification to produce a transcatheter heart valve: Laboratory and animal testing," Catheterization and Cardiovascular Interventions, 63(1), 114, 2004.
  12. Stepan L, Levi D, Carman GP, "A thin film nitinol heart valve," Journal of Biomechanical Engineering, 127(6), 915 - 918, 2005.
  13. Levi, D., Kusnezov, N., and Carman G.P., "Smart materials applications for pediatric cardiovascular devices," PEDIATRIC RESEARCH   Volume: 63, Issue: 5, p. 552-558, 2008
  14. Levi, D., Williams, R., Liu, J., Danon, S., Stepan, L., Mohanchandra, K., Carman G.P., "Thin Film Nitinol Covered Stents: Design and Animal Testing. " ASAIO Journal,  2008
  15. Chun, Y.,  Levi, D. Mohanchandra K.P., Vinuela F., Vinuela, Jr F., Carman, G. P. "Thin Film Nitinol Neurostent for Cerebral Aneurysms," Journal of Biomechanical Engineering, June 2008

 

Publications in Conference and Symposium Proceedings: 

  1. M. Haithem Babiker, Youngjae Chun, Colin Kealey, Gregory Carman, Dan Levi, David Frakes.
    Experimental Fluid Dynamic Investigation of a Novel Hyper-Elastic Thin Film for Cerebral
    Aneurysm Treatment.     ASME 2011 Summer Bioengineering Conference, Jun. 22-25, 2011,
    Farmington, PA. Abstract accepted.
  2. Youngjae Chun, Soojung C. Hur, Colin P. Kealey, Daniel S. Levi, KP Mohanchandra, Dino Di
    Carlo, and Gregory P. Carman. A Novel Hyper-Elastic Thin Film Nitinol Covered Stent
    Significantly Decreases Intra-Aneurysmal Flow In Vitro.     SPIE conference on Smart Materials and
    NDE, Mar. 06-10, 2011, San Diego, CA. Abstract accepted.
  3. Colin P Kealey, Haithem H Babiker, Youngjae Chun, Po-You Lin, K.P. Mohanchandra, David A
    Rigberg, Gregory P Carman, Daniel S Levi, and David H Frakes. In Vitro Evaluation of a Novel
    Hyper-Elastic Thin Film Nitinol Covered Stent for the Treatment of Intracranial Aneurysms    .
    International Stroke Conference 2011, Feb. 09-11, 2011, Los Angeles, CA. Abstract accepted.
  4. YJ Chun, HY Chang, PY Lin, DS Levi, KP Mohanchandra, MC Emmons, MH Seong, AW Tulloch,
    CP Kealey, DA Rigberg, PF Lawrence, and GP Carman. Computational Modeling and Experimental
    Characterization of Hyper-Elastic Thin Film NiTi for Neurovascular Microstent Applications    . 2010
    ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS), Sept.
    28- Oct. 1, 2010, Philadelphia, PA.
  5. Tulloch AW, Chun Y, Kealey C, Mohanchandra KP, Chang J, Milisavljevic V, Levi DS, Carman
    GP, Lawrence PF, Rigberg DA. Hydrophilic Surface Treatment of Thin Film Nickel Titanium Reduces Bacterial Biofilm Production Compared to Commercially Available Endograft Materials.
    2010, Vascular Annual Meeting, June 10-13, 2010, Boston, MA. (Allan W. Tulloch received the
    Society for Vascular Surgery Annual Meeting Award.)
  6. Youngjae Chun, Soojung C. Hur, Colin Kealey, Allan W. Tulloch, Daniel S. Levi, Dino Di Carlo,
    Hsin-Yun Chang, K.P. Mohanchandra, David A. Rigberg, Peter F. Lawrence, and Gregory P.
    Carman. A Novel Neurovascular Stent Covered in Stretchable Thin Film NiTi Significantly
    Decreases Flow into a Wide-Neck Aneurysm In Vitro    . American Society for Artificial Internal
    Organs (ASAIO), May 27-29, 2010, Baltimore, MD.
  7. Colin Kealey, Youngjae Chun, Allan W. Tulloch, Daniel S. Levi, KP Mohanchandra, Gregory P
    Carman, Peter F Lawrence, and David A Rigberg. An In Vitro Examination of the Thrombotic
    Response to Thin Film Nickel Titanium (Nitinol) Under Stenotic Flow Conditions.     2010,
    Arteriosclerosis, Thrombosis and Vascular Biology 2010, Apr. 8-10, 2010, San Francisco, CA.
  8. Youngjae Chun, Daniel S. Levi, Allan W. Tulloch, K. P. Mohanchandra, David A. Rigberg,
    Fernando Vinuela , Fernando Vinuela Jr., Peter F. Lawrence, and Greg P. Carman. Micro-patterned
    Superhydrophilic Thin Film NiTi Endografts for Treating Vascular Diseases.     The International
    Conference on Shape Memory and Superelastic Technologies, May 16-20, 2010, Pacific Grove, CA.
  9. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Allan W. Tulloch, David A. Rigberg,
    Fernando Vinuela, Fernando Vinuela Jr., and Greg P. Carman. Novel Fabrication Processes for Thin
    Film Nitinol Endografts and Evaluation of Endothelialization in Swine Model    . SPIE conference on
    Smart Materials and NDE, Mar. 07-11, 2010, San Diego, CA.
  10. Youngjae Chun, Soojung C. Hur, Colin Kealey, Allan W. Tulloch, Daniel S. Levi, Dino Di Carlo, Hsin-Yun Chang, K.P. Mohanchandra, David A. Rigberg, Peter F. Lawrence and Gregory P. Carman. A Novel Neurovascular Stent Covered in Stretchable Thin Film NiTi Significantly Decreases Flow into a Wide-Neck Aneurysm In Vitro. American Society for Artificial Internal Organs (ASAIO), May 27-29, 2010, Baltimore, MD. abstract submitted.
  11. Colin Kealey, Youngjae Chun, Allan W. Tulloch, Daniel S Levi, Kotekar P Mohanchandra, Gregory P Carman, Peter F Lawrence and David A Rigberg. An In Vitro Examination of the Thrombotic Response to Thin Film Nickel Titanium (Nitinol) Under Stenotic Flow Conditions. 2010, Arteriosclerosis, Thrombosis and Vascular Biology 2010, Apr. 8-10, 2010, San Francisco, CA. abstract submitted.
  12. Youngjae Chun, Daniel S. Levi, Allan W. Tulloch, K. P. Mohanchandra, David A. Rigberg, Fernando Vinuela , Fernando Vinuela Jr., Peter F. Lawrence and Greg P. Carman. Micro-patterned Superhydrophilic Thin Film NiTi Endografts for Treating Vascular Diseases. The International Conference on Shape Memory and Superelastic Technologies, May 16-20, 2010, Pacific Grove, CA, abstract accepted.
  13. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Allan W. Tulloch, David   A. Rigberg,   Fernando Vinuela , Fernando Vinuela Jr., and Greg P. Carman. Novel Fabrication Processes for Thin Film Nitinol Endografts and Evaluation of Endothelialization in Swine Model. SPIE conference on Smart Materials and NDE, Mar. 07-11, 2010, San Diego, CA, abstract accepted.
  14. Youngjae Chun, Daniel S. Levi, Allan W. Tulloch, Soojung C. Hur, Colin Kealey, KP Mohanchandra, David A. Rigberg, Peter Lawrence, Fernando Vinuela, Fernando Vinuelar, Jr., and Gregory P. Carman. Hemocompatible Thin Film Stent-grafts for Treating Neurovascular Diseases. The KSEA 6th Annual Young Generation Technical & Leadership Conference, Jan. 08-10, 2010, Washington D.C., MD. (Received the 3rd Place in Technical Lecture Award)
  15. Allan Wiley Tulloch, Youngjae Chun, Anthony Chau, Komindar P Mohanchandra, Greg P Carman, Peter F Lawrence, and David A Rigberg. Thin-film nickel titanium demonstrates reduced bacterial adherence in vitro compared with commercially available endograft materials. American College of Surgeons 95th Annual Clinical Congress, Oct. 11-15, 2009, Chicago, IL.
  16. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra and Greg P. Carman. Fabrication Processes for Creating Micro Features in Thin Film NiTi Endovascular Grafts. 2009 ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS), Sept. 20-24, 2009, Oxnard, CA.
  17. Youngjae Chun, Allan Tulloch, Daniel S. Levi, K. P. Mohanchandra, Fernando Vinuela, David A. Rigberg and Greg P. Carman. Less
    Thrombogenic Surface of Thin Film Nitinol for Endovascular Grafts    . 22nd European Conference on Biomaterials, Sept. 7-11, 2009, Lausanne, Switzerland.
  18. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra and Greg P. Carman. Self-expandable Thin Film Nitinol Endografts for Vascular Repair: Manufacturing and Short-Term Results in Swine. 4th Frontiers in Biomedical Devices Conference & Exhibition, 2009-83048, June 08-09, 2009, Irvine, CA.
  19. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Fernando Vinuela and Greg P. Carman. Manufacturing and In-vivo Testing of Thin Film Nitinol Micro-Endograft. American Society for Artificial Internal Organs (ASAIO), May 28-30, 2009, Dallas, TX.
  20. Allan W Tulloch, Youngjae Chun, Daniel S Levi, Kotekar P Mohanchandra, Gregory P Carman, Peter F Lawrence, David A Rigberg. Hydrophilic Surface Treatment of Thin Film Nickel Titanium Reduces Platelet Adhesion and Aggregation in vitro and Prevents Endograft Thrombosis in vivo. 2009, Rochester Vascular 2009, May 1-3, 2009, Rochester, NY.
  21. Allan W Tulloch, Youngjae Chun, Daniel S Levi, Kotekar P Mohanchandra, Gregory P Carman, Peter F Lawrence, David A Rigberg. Hydrophilic Surface Treatment of Thin Film Nickel Titanium Reduces Platelet Adhesion and Aggregation in vitro and Prevents Endograft Thrombosis in vivo. 2009, SVS 2009 Research Initiatives in Vascular Disease Conference, Apr. 28, 2009, Washington, D.C.
  22. Youngjae Chun, Daniel S. Levi, Allan W. Tulloch, K. P. Mohanchandra, Fernando Vinuela, Fernando Vinuela, Jr. and Greg P. Carman. Manufacturing and In-vivo Testing of Thin Film Nitinol Micro-Endograft. Technology Forum 2009, Apr. 23, 2009, CNSI (California Nano Systems Institute), UCLA, Los Angeles, CA.
  23. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra and Greg P. Carman. Superelastic NiTi Thin Film Small Vessel Graft for Vascular Repair. SPIE conference on Smart Materials and NDE, Vol. 7288, Mar. 08-12, 2009, San Diego, CA  (Received the Honorable Mention in Best Student Paper Competition Award)
  24. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra and Greg P. Carman. Thin Film Nitinol Microstent for Aneurysm Occlusion. 2008 ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS), 2008-389, October 28-30, 2008, Ellicott City, MD (Received the Best Student Paper Award in Bio-inspired Smart Materials and Structures)
  25. David A. Rigberg, Youngjae Chun, K.P. Mohachandra, Greg Carman, Peter Lawrence. Thin Film Nitinol (NiTi): A Novel Material for Aortic Stent Grafts. Western Vascular Society 23rd Annual Meeting, September 13-16, 2008, Napa, CA.
  26. Youngjae Chun, Daniel S. Levi, K. P. Mohanchandra, Fernando Vinuela, Fernando Vinuela, Jr. and Greg P. Carman. Thin Film Nitinol Micro-Endograft for Interventional Procedures. Technology Forum 2008, May 27, 2008, UCLA, Los Angeles, CA.
  27. Youngjae Chun, K. P. Mohanchandra, Daniel Levi, and Greg P. Carman. Thin Film NiTi Biomedical Applications. The 18th Korean-American Scientists and Engineers Association, Feb. 09, 2008, California Institute of Technology, Pasadena, CA.
  28. Youngjae Chun, K. P. Mohanchandra, Lenka Stepan, Daniel S. Levi, and Greg P. Carman. Manufacturing and Testing of Thin Film NiTi for Biomedical Applications. The 44th Annual Technical Meeting of the Society of Engineering Science, Oct. 21-24, 2007, TAMU, TX.
  29. Youngjae Chun, Daniel Levi, and Greg P. Carman. Thermomechanical Behavior and Biomedical Applications of NiTi Smart Materials. KAIST_UCLA Student Workshop, Feb. 2007, UCLA, Los Angeles, CA.
  30. Youngjae Chun. Thermomechanical Behavior and Biomedical Applications of NiTi Smart Materials. The KSEA 3rd Annual Young Generation Technical & Leadership Conference, Jan. 07, 2007, New York, NY.
  31. YJ Chun, LS Stepan, GP Carman, DS Levi, D. Rigberg. Thin Film Nitinol Medical Devices. Women & Philanthropy CASIT Event Production, Nov. 16, 2006, Center for Advanced Surgical and Interventional Technology, UCLA Hospital, Los Angeles, CA.
  32. Stepan LL, Levi DS, Carman GP, "A thin film nitinol heart valve," Proceedings of the 2004 ASME International Mechanical Engineering Congress 2004, Anaheim, CA, 13 November 2004.
  33. Levi DS, Raff E, Stepan LL, Liu J, Williams RJ, Moore JW, Carman GP, "Use of a covered stent modification to produce a transcatheter heart valve: Laboratory and animal testing," ASAIO 2005, 51(6), 719 - 724, 2005.
  34. Levi DS, Stepan LL, Carman GP, Jardine AP.  "Development and testing of manufacturable thin film TiNi for medical devices," Proceedings of the SMST, in press.
  35. Chun Y., Levi D., Mohanchandra K.P., and Carman G.P. , "A Thin Film Nitinol Micro-Endograft for Interventional Procedures," Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS2008), October 28-30, 2008, Ellicott City, Maryland, in press

Abstracts:

  1. A. Tulloch, Y. Chun, A. Chau, K. Mohanchandra, G. Carman, P. Lawrence, D. Rigberg. Thin-film nickel titanium demonstrates reduced bacterial adherence in vitro compared with commercially available endograft materials. Journal of the American College of Surgeons, Volume 209, Issue 3, 2009, p.S141.
  2. Allan W Tulloch, Youngjae Chun, Daniel S Levi, Kotekar P Mohanchandra, Gregory P Carman, Peter F Lawrence, David A Rigberg. Hydrophilic Surface Treatment of Thin Film Nickel Titanium Reduces Platelet Adhesion and Aggregation in vitro and Prevents Endograft Thrombosis in vivo. Arterioscler. Thromb. Vasc. Biol. 2009; 29; e9-e130, Journal of the American Heart Association, p.99.
  3. Youngjae Chun, Daniel S Levi, KP Mohanchandra, Allan Tulloch, Gregory P Carman. Manufacturing and In-vivo Testing of Thin Film NiTi Endograft. Journal of the American Society for Artificial Internal Organs, 2009, p.167.
  4. Block David A. Rigberg, Youngjae Chun, K.P. Mohachandra, Greg Carman, Peter Lawrence, "Thin Film Nitinol (NiTi): A Novel Material For Aortic Stent Grafts," Western Vascular
  5. Stepan L, "A thin film Nitinol artificial heart valve," 2004 UC Systemwide Bioengineering Symposium, Irvine, CA, 26-28 June 2004.
  6. Jardine AP, Baure G, Le AN; Carman GP, "Development and testing of manufacturable thin film TiNi for medical devices" Materials & Processes from Medical Devices Conference 2004, St. Paul, MN, 25-27 August 2004, 112-115.
  7. Stepan LL, Levi DS, Carman GP, "A thin film nitinol artificial heart valve," 2004 ASME International Mechanical Engineering Congress and Expo, Anaheim, CA, 13-20 November, 2004
  8. Stepan L, "Fabrication and testing of a thin film nitinol heart valve," 2005 SPIE International Symposium, Smart Structures & Materials/NDE, San Diego, CA, 7-10 March 2005.
  9. Chun, Y, Levi, D., Stepan, L., and Carman, G.P., "Manufacturing and Testing of Thin Film NiTi for Biomedical Applications," 44th Annual Technical Meeting Society of Engineering Science, Texas A&M University, College Station, TX, 2005

Theses and Dissertations:

  1. Stepan L, "Development and testing of a thin film nitinol heart valve," PhD Dissertation, University of California, Los Angeles, 2006.