Vascular Device Forum

Medical Malpractice Vascular Surgery/Intervention-Current Status

Today, I received an email from a colleague lamenting how disappointing it is that there has been no support for malpractice reform in the current discussion on healthcare reform. A recent article in the liberal New York Times source summarized the situation by suggesting that malpractice is responsible for 3% of overall healthcae costs (relatively minimal). However my impression is that the study underestimated the significant impact that impending medical liability has on increasing costs of providing care in terms of a constant cycle of unneccessary test and labs for defensive purposes. To the point that young doctors are now trained in the art of practicing defensible medicine. I posted previously on medical malpractice in vascular surgery and vascular disease treatment and it was well received. Issues like limb ischemia, gangrene and amputation are common topics with significant medical legal liability.

Download Leb bypass youtubeshort

To be certain, there are egregious cases of medical negligence that virtually indefensible, however from what I have seen, the vast majority of malpractice cases are frivolous and even if they dont make it to trial, they cause a great deal of anguish, increased costs and loss of professional integrity. For this reason, Im always available to participate in defending a vascular practitioner vigorously as a vascular expert.

I actually think that far more systems errors occur that result in patient injury than direct physician mediated injuries. And the data would suggest that most of these medical errors dont result in medical malpractice litigation

My colleague sent me a couple links for agencies that advertise for vascular surgery, cardiology, cardiac surgery medical malpractice cases. Its always interesting to see what the process is and to hear plaintiffs describe the potential errors in management during the review of a medical malpractice case. For example read a list of vascular surgery medical malpractice cases and awards here

Also read about some sample cases here These cases are quite fascinating

Here at the VascularDeviceForum.com we spend a lot of time talking about the safe use of technology for the treatment of vascular disease and the ultimate benefit of our patients. But lets not forget that its a tough world out there for the vascular practitioner

Zilver PTX next generation Drug eluting stent for SFA-Cook Medical

 

Cook Medical cook trial has received EU's CE Mark to market the Zilver® PTX® paclitaxel eluting nitinol stent for the treatment of peripheral artery disease in the superficial femoral artery. The paclitaxel, a drug also used in the TAXUS cardiac stents by Boston Scientific, has been licensed from Angiotech. The interesting thing about the Zilver® PTX® is that the paclitaxel is attached to to the nitinol frame without the use of any polymer or other anchoring agent, which avoids leaving any plastics behind in the vessel once paclitaxel dissolves. Previous concerns about the early thrombosis of drug eluting coronary stent tempered enthusiasm somewhat however it appears that the ploymer used to attach the drugs was the culprit as opposed to the stent itself. The Proprietary technology from cook appears to have addressed the issue.

From Cook's announcement of the approval:

The CE Mark follows the world's largest-ever clinical trial for a peripheral stent, led by Dr. Michael Dake, professor in the Department of Cardiothoracic Surgery at Stanford University Medical School and medical director of the Cath/Angio Laboratories at Stanford University Medical Center, Palo Alto, California. The data published in the Zilver PTX registry involved 791 patients from Europe, Russia, Canada and Korea and demonstrated highly positive results. Only 8 percent of all patients with de novo (new) lesions needed a reintervention to reopen the artery in the first 12 months — a rate significantly surpassing existing treatments for PAD in the SFA, such as balloon angioplasty and bare metal (non-drug-eluting) stents.

Also, specific patient groups that are often very hard to treat, such as diabetics and patients with in-stent restenosis (those treated previously with a noncoated stent), were shown in the trial to benefit from the Zilver PTX. As the trial data indicate, the superior results achieved in the first year have been largely maintained throughout 24 months, an important clinical milestone. In comparisons with other trial data obtained, the Zilver PTX stent showed a reduction in reintervention of between 50 percent and 75 percent, an important patient benefit

Cook Medical has been an innovator in utilizing new media to enhance clincial outcomes. (See The Landing Zone)Cook also has initiated a first-of-its-kind open clinical database on SFA treatments. The SFA Open-Registry provides physicians with an opportunity to exchange ongoing, real world treatment results. Utilizing an intuitive web interface, clinicians may track their patients, view the medical community's trends in treating PAD and determine the most effective treatment options. Transparency will be a central objective of the SFA Open-Registry, with results for all treatment types available to participating physicians.

Another key breakthrough is Cook's commitment to a patient-focused strategy that should make the device available to virtually any PAD patient who needs it, Lyles explained. As part of its ongoing corporate mission to help reduce global health care delivery costs, Cook has adopted a unique 'affordable innovation' strategy aimed at reducing any potential financial or reimbursement barriers to its widespread adoption as the standard of care for PAD in the SFA.

Cook licenses the rights to use paclitaxel on peripheral stents and other noncoronary medical devices from Angiotech Pharmaceuticals, Inc., of Vancouver, British Columbia, Canada (http://www.angiotech.com, NASDAQ: ANPI, TSX: ANP). In the United States, the Zilver PTX Drug-Eluting Stent is an investigational device not available for sale at this time.

Will Definitive leave Silverhawk Atherectomy (EV3) Dead in the Water

The Definitive Trial for atherectomy was intiated in April 2009 to evaluate the efficacy of the Silverhawk Atherectomy Device from EV3. The Silverhawk technology emerged on the scene to much fanfare with an aggressive marketing strategy in the early part of the decade. At that time, there was very little clinical data to support benefit of the device versus the available clincal alternatives POBA, Stent and surgical bypass.

Aggressive marketing toward groups like podiatrists endeared the technology and sealed its role in the treatment of PAD. Almost 10 years later, there is still little information available about the benefits of the technology outside of centers who tout excellent results with high volume useage. (
See Dr Mckinsey's comments by clicking here

Unfortunately, most patients are treated outside of high volume centers that have practitioners with well developed experiences and judgments about this technology. At this point, I believe that the 80/20 rule is in effect. The low volume guys hae virtually stopped using the technology and the high volume guys ie 20% of proceduralist are responsible for 80% of the volume and company revenue.

The question I raise is will the definitive trial answer questions and resolve the dilemma to establish a role for Silverhawk Atherectomy or will it leave Silverhawk technology and EV3 dead in the water. Im sure that competitors wait anxiously. ie  Diamondback from CSI and Jetstream G2 from Pathway Medical. If the results are good, they will piggy back off the results obtaining borrowed credibility from the study of atherectomy. If the results are bad, they will run for cover claiming a different atherectomy technique

Vena Caval Filter Update: Is anyone still using the Trapease/Optease?!?

Pulmonary Emboli (PE) are responsible for more deaths annually than breast cancer, AIDS and motor vehicle accidents combined. Prevention of Pulmonary embolism represents an important aspect of care for the vascular practioner. Numerous filters are available for implantation to prevent pulmonary embolus. Available filter types are listed below 

IVC filter brands

• B Braun Tempofilter IVC filter (retrievable)
• B Braun VenaTech LGM IVC filter (no longer sold)
• B Braun VenaTech LP IVC filter
• Bard G2 IVC (retrievable, unlimited indwell time)^[2]
• Bard Recovery IVC filter (retrievable) (no longer sold)
• Bard Simon Nitinol IVC filter^[3]
• Boston Greenfield IVC filter
• Cook Birds Nest IVC filter
• Cook Celect IVC filter (retrievable)
• Cook Gunther Tulip IVC filter (retrievable)
• Cook Gianturco-Roehm Bird's Nest IVC Filter (not retrievable)
• Cordis OptEase IVC filter (retrievable, 23 day indwell time)^[4]
• Cordis TrapEase IVC filter
• Mobin-Uddin Umbrella IVC filter (no longer sold)
• ALN IVC filter (retrievable)
• Rex Medical Option IVC filter (retrievable) (in clinical trials)

Recent data has emerged that the Optease/TrapEase device from Cordis are associated with a higher incidence of vena caval thrombois. Singer et al in JVIR 2009 Jun;20(6):799-805 and Leask RL et al JVIR 2004 May;15(5):485-90 used different models to assess the TrapEase's function. Singer et al using a three dimensional computer model of the TrapEase filter, examined the hemodynamics of steady state flow in the unoccluded and parially occluded filter. The study concluded that the upstream trapping position of the TrapEase filter leads to a potentially thrombogenic region of stagnant and or recirculating flow with low shear stress. Furthermore, the authors stated "these findings are supported by clinical studies showing an increased incidence of occlusive and nonocclusive thrombi"

Leask et al summarized that "there is a tendency for clots to be trapped between the filter and the vessel wall in the inferior inlet region. A clot in this region will generate a large region of flow stagnation/recirculation that is considered to be prothrombotic. In addition, a significant amount of the filter wire will be embedded in this region, which may promote thrombosis."

I would be interested to hear the feedback of practicing clinicians. I suspect that there is a specturm of opinions depending upon the type of practice ie vascular surgeon, IR and the setting ie community, academic. An extensive caval thrombus patient is likely to require lysis and if the filter placement individual is not the person that performs thrombolysis or if the patient is transferred to another facility do to extensive caval thrombus, then the person who placed the filter might not be aware of this type of potentially delayed complication.

Elsewhere,recently companies like Cook Medical have introduced technical iterations on currently existing devices like the Celect and Tulip vena caval devices. The NavAlign delivery system, available for both the Cook Celect® and Günther Tulip™ filters, is designed to minimize trauma and streamline filter placement with features unavailable on any other existing deployment system. A hemostatic valve minimizes blood loss at the point of entry, while a multipurpose dilator has radiopaque sizing bands and flushing sideports that decrease fluoroscopy time and the amount of contrast medium required.

I suggest that the the OptEase and TrapEase have had market share because of the first entry advantage and the associated clinical ease of deployment, however with advances in technology ongoing re-evaluation of practice patterns are necessary to provide the best outcomes to our patients

View deployment of the Guenther Tulip from Cook Medical

Download EducationMedia

Cook Medical's TX2 ProForm Thoracic Endograft

I posted a previous forum on ProForm technology. Here is animation for the device deployment.

Download TX2-PROFORM-1TX2 Proform

Earlier post on the Zenith TX2 ProForm

 

Cook Medical's Zilver PTX stent performs well in Europe

In August, Cook Medical  announce CE Mark approval for the Zilver PTX Stent, the first-ever drug-eluting stent designed specifically to treat severe blockages in the superior femoral artery (SFA). As you may know, the paclitaxel-coated Zilver PTX is also the first DES that eliminates the use of a polymer to adhere the drug to the stent, significantly diminishing the occurrence of potentially dangerous reactions experienced in some patients.

Approval of the polymer-free Zilver^® PTX^® Drug-Eluting Peripheral Stent from Cook Medical, a world leader in minimally invasive diagnostic and interventional devices, represents a global landmark in effective peripheral intervention for treating PAD, a chronic disease affecting tens of millions of patients worldwide that is a leading cause of leg amputation and shortened lifespans.

Cook’s Zilver PTX is specifically designed and approved to treat PAD affecting the main blood vessel in the thigh, the superficial femoral artery (SFA). It is a self-expanding stent made of nitinol, a space-age ‘shape memory’ metal that offers unique mechanical advantages for a stent in the SFA.

By eliminating the need for a polymer or plasticizing agent to hold the drug to the stent body, Cook has created a medical breakthrough that solves two key problems. First, it allows targeted delivery of a drug (paclitaxel) proven to reduce the renarrowing (restenosis) of arteries opened using balloon angioplasty. Second, by eliminating the need for a polymer, which was left behind on the body of earlier drug-eluting stents after the drug dissolved into the surrounding tissues, Zilver PTX avoids the potential patient risks posed by leaving a permanent foreign, plastic substance in the body. In addition, the Zilver stent was proven during its clinical trial to be the most durable peripheral stent available, suggesting even greater patient safety, according to the clinical trial data.

The CE Mark follows the world’s largest-ever clinical trial for a peripheral stent, led by Dr. Michael Dake, professor in the Department of Cardiothoracic Surgery at Stanford University Medical School and medical director of the Cath/Angio Laboratories at Stanford University Medical Center, Palo Alto, California. The data published in the Zilver PTX registry involved 791 patients from Europe, Russia, Canada and Korea and demonstrated highly positive results. Only 8 percent of all patients with de novo (new) lesions needed a reintervention to reopen the artery in the first 12 months – a rate significantly surpassing existing treatments for PAD in the SFA, such as balloon angioplasty and bare metal (non-drug-eluting) stents.

Also, specific patient groups that are often very hard to treat, such as diabetics and patients with in-stent restenosis (those treated previously with a noncoated stent), were shown in the trial to benefit from the Zilver PTX. As the trial data indicate, the superior results achieved in the first year have been largely maintained throughout 24 months, an important clinical milestone. In comparisons with other trial data obtained, the Zilver PTX stent showed a reduction in reintervention of between 50 percent and 75 percent, an important patient benefit.

“The awarding of the CE Mark is set to herald a revolution in the treatment of peripheral arterial disease,” comments Dr. Michael Dake. “This global study proves that the Zilver PTX has the integrity, safety and durability needed to successfully address many of the well-known limitations of current treatments for the management of PAD.”

Rob Lyles, global leader and vice president of Cook Medical’s Peripheral Intervention division states, “We’ve specifically designed the Zilver PTX to be safer and more effective for PAD patients by engineering this device for the unique demands of treating this disease in the SFA. It’s polymer-free, it’s fracture resistant, and through the largest trial of its nature in history, it’s been clinically proven to be significantly more effective in treating peripheral arterial disease in the SFA than other treatment modalities.

“Our unique ability to adhere the drug to the stent without using a polymer is a major clinical advantage. It eliminates the risk some patients may face due to reactions and other potentially poor outcomes that are associated with polymer coatings used on current generations of drug-eluting stents. It’s a truly exciting time for Cook Medical and our partners, as well as for physicians and patients alike. With the European launch of this first-of-its-kind 21^st century medical technology, we are truly at the vanguard of a revolution in peripheral intervention.”

Following more than 1,200 patients treated worldwide during its clinical evaluation and CE Mark approval on July 24, 2009, the first commercial implantations of the Zilver PTX stent were conducted August 10 in a coordinated effort by physicians in the United Kingdom, Germany, France, Holland, Belgium, Sweden, Switzerland and Spain. In the United States, the Zilver PTX drug-eluting stent is an investigational device not available for sale.

This breakthrough technology represents a major innovation in the treatment of PAD which occurs in the challenging terrain of the SFA. The stress and strain forces of this dynamic vessel, especially at the adductor canal requires unique technology. Thus far, the data demonstrates fracture resistance and avoidance of the sequellae associated with drug eluting platforms.