medtechmatters.com

Antoine Lafont, MD, PhD

VANISHING STENTS - PART 2  What if there were a stent that could promote natural remodeling of an injured artery after angioplasty, and then just disappear? "Just three years ago bioresorbable stents seemed to be more of a nice to have than a need to have.  After all, drug-eluting stents (DES) were seen as the answer to restenosis and showed very minimal risks to patient safety. Johnson & Johnson and Boston Scientific had the clear lead in introducing Cypher and Taxus, respectively, to the interventional community, with Medtronic, Guidant, and Abbott Laboratories bringing up the rear. Then in September 2006 at the World Congress of Cardiology meeting...DES were linked to a four-letter word delivering a new danger corporate executives once again began asking a question they thought they had answered: why deploy a permanent implant on a short-term mission of clearing a coronary artery?" (Source: 'Bioabsorbable Stents', Start-Up, January 2007)  In part two of “Vanishing Stents”, we again consider Paris-based ARTERIAL REMODELING TECHNOLOGIES ("ART").  ART's stent is designed to provide the requisite initial acute mechanical scaffolding, but, as it dismantles due to bioresorbability, the possibility of arterial remodeling returns to the artery.  Our expert is Antoine Lafont, MD, PhD, Professor of Medicine at the University of Paris; Head of Interventional Cardiology at Georges Pompidou Hospital in Paris; and, Chairman of the Interventional Cardiology Group of the European Society of Cardiology (ESC). Dr. Lafont is a co-founder of ART. Click here to listen.

Dr. Christian Ottensmeier

DNA VACCINES - Researchers at the Centers for Disease Control and Prevention reported in the November 2007 issue of JAMA that conventional vaccines have cut disease deaths by 99%, but have been limited to only 13 disease targets.  DNA vaccines, on the other hand, have been touted as some day preventing or curing cancer, AIDS and a litany of other infectious diseases.  But the promise of DNA vaccines has been hindered by a lack of an effective delivery vehicle.  In fact, delivering DNA vaccine inside targeted cells has proven to be a formidable challenge.  Now, there is growing evidence that suggests vaccine delivery via electroporation might be the answer.  In this episode, we speak with Dr. Christian Ottensmeier, Professor of Experimental Cancer Medicine and Senior Clinical Research Fellow at the University of Southampton, one of the UK’s foremost research universities.  Dr. Ottensmeier is Principal Investigator for an ongoing Phase I/II clinical study that has two arms: without, and with, the use of  Inovio Biomedical’s electroporation system to deliver DNA vaccine to subjects with prostate cancer.  Dr. Ottensmeier reported early human data from his study at this year’s AACR (American Association for Cancer Research) annual meeting—data which suggest that use of electroporation to enhance the potency and delivery of DNA vaccines has significant potential.  Click here to listen.

HOSPITAL-ACQUIRED INFECTIONS   In the United States, attempts to control hospital-acquired (“nosocomial”) infections are proving ineffective, according to the Government Accountability Office (GAO).  In fact, hospital-acquired infections are estimated to be one of the top-ten causes of death in the U.S., claiming 90,000 lives every year.   In this episode, we look at how Dijon Hospital in Dijon, France, is protecting its most vulnerable patients with a new mobile infection control technology from AirInSpace.  The company’s device, called PlasmairT2006, was recently cleared by the FDA to be used in U.S. hospitals.  At Dijon Hospital, there are 40 mobile Plasmair™ units being used in the pediatric and adult haematology wards, where immunocompromised cancer patients are at high risk from deadly airborne pathogens such as aspergillosis.  We speak with two doctors at Dijon Hospital: Dr. Denis Caillot, head of Clinical Haematology, and his colleague, Dr. Ludwig Aho, head of Hospital Hygiene and Epidemiology.  Click here to listen.

Professor Joachim Schofer

UNCLOGGING THE FORKS: A bifurcation is an area where one main blood vessel branches out into two smaller vessels, like a fork in the road: one being the continuation of the main vessel, the other one often referred to as the side branch.  Narrowings at a bifurcation are very common—more than 500,000 bifurcation coronary lesions are treated each year. But even using drug-eluting stents (DES), the restenosis rate in bifurcations is a startling 23-26 percent. The difficulty in treating bifurcated lesions with conventional interventional approaches — i.e., angioplasty with stenting — lies in the troublesome anatomical terrain in which the lesions occur. Having to work at the Y-shaped intersection of two vessels, interventionalists have to maneuver multiple guidewires and stents, which often present challenges that increase the procedure’s complexity.  Equally important, current stents, since they are not designed to fit bifurcated vessels, do not properly scaffold the area—and specifically the side branch entrance.  Thus, having a device specifically designed for bifurcations—which is a significant unmet clinical need—should help avoid many of these clinical problems.  In this episode, Professor Joachim Schofer of the Center for Cardiology and Vascular Interventions, Hamburg, Germany, gives his perspective on bifurcated stents, in general, and the Stentys birfurcated stent, in particular. Click here to listen.  CLICK HERE TO DOWNLOAD THE PODCAST TRANSCRIPT.

Richard Heller, MD

DNA Vaccines   Conventional technology used to create vaccines for a limited number of diseases such as polio and tetanus is not effective against cancer, HIV, hepatitis C, and a legion of other deadly and disabling diseases.  But the promise of using a new generation of technology—DNA vaccines—to stimulate the body’s own immune responses has been curtailed by a lack of an effective delivery system.  Use of virus carriers poses uncertainties regarding potential mutation and unwanted immune responses against the carrier. Lipids and the “gene gun” may not achieve sufficient levels of immune response.  And none of these methods is inexpensive. Now, there is growing evidence that an electroporation-based delivery system from Inovio Biomedical (AMEX: “INO”) has the potential to become a preferred delivery method for a wide range of therapeutic and preventive vaccines.  In this episode, Dr. Richard Heller of the University of South Florida’s College of Medicine and the Moffitt Cancer Center discusses how electroporation “works” to deliver a DNA vaccine and enhance the potency of that vaccine as well.  Dr. Heller is currently the principal investigator in an ongoing Phase I melanoma clinical study to test the safety and tolerability of direct intratumoral delivery of plasmid-based IL-12 using the electroporation system of Inovio Biomedical.  Click here to listen.

Robert G. Johnson, M.D., Neurosugical Assoc., San Antonio, TX

There is significant interest among spine surgeons for a bone graft substitute that could be used during lumbar spine surgery to help facilitate fusion and thereby eliminate the need to harvest a patient’s own bone.  In this episode, Dr. Robert Johnson, a spine surgeon based in San Antonio, Texas, talks about his ongoing study using autologous adult stem cells to facilitate spinal fusion instead of using bone harvested from a patient’s pelvis, which may create two potential problems: (1) graft site morbidity (complications may include bleeding, infection, and chronic pain at the donor site in the pelvis); and (2) failure to fuse.  These are the two primary reasons that there is great interest in creating a bone graft mechanism for use in a spine fusion procedure instead of using a patient’s own bone. Click here to listen.

In this episode, we'll take a look at what's new in treating cellulite, focusing on an emerging, privately funded aesthetics company called SmoothShapes®.  The Company's FDA-cleared SmoothShapes® 100 device is a painless, non-invasive laser-based system that works gradually and effectively to improve the appearance of cellulite by reducing its underlying cause: subcutaneous fat.  A multi-center clinical study of the SmoothShapes® device concluded that 81 percent of patients experienced significant volumetric reduction in subcutaneous fat. SmoothShapes® 100 is the only system that has validated its claims with rigorous and extensive before-and-after MRI evaluations, in stark contrast to the random and subjective photography that typifies this category. Click here to listen.

Accuracy of pedicle screw placement is still an issue in spine surgery. Indeed, published rates of intraoperatively misplaced pedicle screws range from 10 to 40 percent.  Of that number, 2 to 10 percent have resulted in direct pathological consequences such as spinal cord damage.  Consequently, liability risk for spine surgeons are high.  PediGuard?, which is developed and marketed by SpineVision, is the first patented, wireless, hand-held drilling instrument capable of accurately detecting changes in tissue type, thus alerting surgeons to potential pedicular or vertebral breaches during pedicle screw site preparation. Click here to listen.