Device Market Research Required for Vascular Closure

Cardiac Catheterization - Closure market threatened as Trans Radial access gains US acceptance

Radial vs Femoral Access - Closure Device Market faces serious impact

While the US is slow to adopt this procedure it is somewhat inevitable that serious impact will be felt by companies involved in the vascular closure market.... The Body's Highway Interventional medicine, or catheter-based therapy, utilizes the body's circulatory system as a "highway" -- and avoids open surgery by threading catheters into arteries and delivering medicine and devices to the affected areas from the "inside-out". This highway can be accessed by several "on-ramps": the femoral artery in the groin, the radial artery in the wrist and the brachial artery in the elbow.

hollow catheter tip

The Femoral (Groin) Approach
When attempting to access the coronary arteries to clear a blockage with a balloon, or place a stent to hold the artery open, the most often used entry point to the circulatory system has been the femoral artery. A small puncture is made with a hollow needle, which then allows a long tube, called a catheter, to be threaded into the femoral artery, up and around the aorta and into the coronary arteries. This femoral approach, sometimes called the Judkins technique (afterDr. Melvin Judkins who invented it in the 1960's) is the standard way in which most catheter-based procedures are done in the U.S.

However, there are some limitations to the femoral approach. The femoral or nearby arteries may be diseased and will not allow a catheter to pass easily. Sometimes a patient is overweight or obese, and the femoral artery is buried deep underneath the fatty tissue, making it hard to access, and then equally hard to compress after the procedure -- a necessary step in stopping the bleeding. In some cases, bleeding that is not immediately visible to the eye can occur in a backwards fashion into the body cavity -- this can be seen as a discoloration, like a bruise, that expands and must be treated. The possibility of involvement of the femoral nerve also exists. These types of complications are small in number, often quoted at 3%.

Invention of the Radial Technique
In the late 1980's, a French-Canadian physician, Dr. Lucien Campeau, started using the right radial artery, which is located in the wrist, as an entry point for diagnostic catheterizations. While the radial artery is slightly smaller than the femoral, it is still large enough to allow most catheters to traverse the distance to the coronary anatomy. In fact the radial artery was initially harvested and used in coronary artery bypass grafts.

By 1992 a group in Amsterdam, headed by Dr. Ferdinand Kiemeneij, had begun exploring ways to use the radial artery for interventional procedures, such as delivering balloons and stents. They were somewhat limited by the early equipment, but as catheters and stents became lower profile, thinner and easier to manipulate, the ability of physicians to use the radial artery increased. Most devices today can be delivered successfully using the radial artery.

Advantages of the Radial Approach
Most of the disadvantages of the femoral technique are nonexistent in the radial, also called the transradial approach. Even in obese patients, the radial artery is close to the skin surface, making the initial needle puncture simple and straight-forward. For the same reason, when the procedure has been completed, a short compression of the radial artery can stop the bleeding (achieve hemostasis) -- even when the patient has been aggressively anticoagulated with medicines to keep blood clots from forming, more and more common in the modern cath lab. Should any bleeding occur, it can be seen immediately. Finally, unlike the proximity of the femoral artery to the femoral nerve, the radial artery is not close to a major nerve, so the likelihood of "nicking" a nerve during the procedure is very low.

While complications are less common with the radial technique, the advantage experienced by all radial patients is that there is no longer any need to lie flat and still for 4-6 hours, or to experience what is sometimes a painful manual compression of the artery to curb the bleeding. Patients leave the catheterization lab and are able to sit up and walk almost immediately. Because of the simpler healing process for the arterial puncture in the wrist, certain patients may also be discharged home without having to spend the night.

The progress in the treatment of coronary artery disease has evolved to the point that when you compare heart bypass surgery from two decades ago with stenting done today via the transradial approach, what was a 4 hour major open heart operation, with general anesthesia, a week or more in the hospital and months of recovery, can now in some cases be performed as an outpatient procedure.

Is the Radial Approach for Everyone? There are a few prerequisites for patients to be a candidate for the transradial approach. The first is confirmation of a dual, or "protected", blood supply to the hand. The radial artery loops around the hand and joins the ulnar artery. Both arteries supply blood to the hand and fingers. It is precisely this dual blood supply that makes the radial technique safe. Should the radial artery close up (a complication seen in a small percentage of cases) the clinical result tends to be benign, because the ulnar artery continues to function. The first step a cardiologist takes in deciding on the radial approach is an Allen test to assess that both radial and ulnar arteries are functioning normally -- a simple test that can be done by compressing the arteries by hand at bedside or in the doctor's office. If they are not normal, then the femoral approach is preferred. Some other contraindications exist, such as the need to use larger devices during the angioplasty, pre-existing bypass grafts in certain areas or tortuous vessels that may prevent the catheter from navigating to the coronaries from the arm. About 30-40% of patients are not candidates for radial access.

While the complication rate with the radial approach is extremely low, there is always some risk with any medical procedure. It is important for patients to discuss the risks and benefits of the femoral vs. radial approaches, as these can vary for each individual.

Limited Utilization in the United States
The more frequent reason that patients are not offered the radial approach is that only a relatively small percentage of interventional cardiologists in the U.S. are trained in the technique. Parts of Europe and Japan do 40% or more of their cases using the radial artery, but in the U.S. estimates are in the low single digits -- although those U.S. cardiologists and radiologists who have learned the radial technique tend to use it for many, if not most, of their patients.

The reasons for this low penetration are several: lack of economic incentive due to the reimbursement structure, lack of patient awareness that this alternative exists, and lack of trained cardiologists. The situation, however, is changing. More and more practices are beginning to see the advantages in lower complication rates, increased patient satisfaction and even cost-savings (complications can be expensive to manage).

The femoral approach has been the gold standard for many years. Moving to the newer radial technique requires specialized training and advanced skills. Training opportunities are increasing as computer simulation models are being developed and a number of hospitals, both in and outside of the U.S. are now offering programs and mentorships. Current signs point to the increasing use of the radial technique in the U.S.

Interested in TransRadial Training? Click Here

Cost-Effectiveness of the Radial versus Femoral Artery Approach to Diagnostic Cardiac Catheterization

Cardiodex

CardioDex is a privately owned company engaged in the development, manufacturing, and marketing of devices for arterial access site closure, following catheterization procedures.

CardioDex has developed state-of-the-art disposable devices; EpicloseTM and EpicloseTM Plus that do not use any glue, collagen, suturing or other foreign materials thus no residual material is deposited in the patient’s body.
CardioDex's products expedite arterial closure through hemostasis. The process relies on familiar balloon inflation/deflation techniques, which apply selective pressure precisely over the puncture site. The products do not require exchange of the introducer sheath.
CardioDex's products address both the diagnostic and therapeutic markets.

New treatment method in sight in cardiac surgery

A joint clinical trial conducted by the University Hospital and the University of Gothenburg, Sweden, found that an element in human blood, fibrinogen, is likely more vital to the blood's clotting ability in connection with heart surgery than previously considered. If the patients also receive a dose of fibrinogen prior to the procedure, this reduces the risk of haemorrhage during and after surgery. These results may open the door to new strategies in reducing bleeding complications in cardiac surgery.

Each year over 7,000 Swedes undergo open-heart surgery, most commonly a coronary artery bypass or a valve replacement. It's a major procedure during which the heart and lungs are stopped and their functions are temporarily replaced by a heart-lung machine, or CPB pump.

'But the use of a CPB pump has negative effects on the blood's clotting ability, and those effects last a few hours after the operation,' says Dr Martin Karlsson at Sahlgrenska Academy at the University of Gothenburg, author of the thesis. 'This leads to a risk of bleeding. It's unclear why certain patients have more problems than others, but several factors may be involved.'

Fibrinogen is one of the most important coagulation proteins in our blood, and the thesis shows that the amount of fibrinogen in the blood is more important than previously thought to ensure clotting after heart surgery.

'We found that the amount of fibrinogen in the patient's blood immediately prior to bypass surgery is directly related to how much the patient bleeds afterwards, and also to the need for blood transfusions after surgery. As a rule, patients with lower levels of fibrinogen in their blood prior to surgery bleed more, even if they have levels that were previously perceived as normal and sufficient.'

In one part of the trial, bypass patients with low levels of natural fibrinogen in their blood were pre-treated with fibrinogen concentrate before the operation. This reduced the amount of bleeding and the need for transfusions during and after surgery compared with a control group, and the pre-treated patients showed no signs of side effects.

'Treatments such as this have never been tried on patients before, and this trial was only a pilot study, with a small number of patients,' Karlsson explains. 'So it's too early to draw any real conclusions, but the results are promising and larger trials have already begun.'

Karlsson hopes that if the results of the pilot study can be confirmed, then fibrinogen concentrate could be used as a preventive therapy for patients about to undergo a surgical procedure and in other instances where the risk of haemorrhage is high. This would offer a new treatment option for the large number of patients undergoing cardiac surgery each year, possibly also for other surgical procedures.

Ethicon Endo-Surgery Introduces Two New Staplers for Open Surgical Procedures at ASCRS

MINNEAPOLIS, May 14 /PRNewswire/ -- Ethicon Endo-Surgery (EES) today announced the launch of two new surgical staplers designed to optimize efficiencies and compression during open surgery. The Ethicon Endo-Surgery Linear Cutter 55/75, engineered with novel staple technology and selectable staple heights in one cartridge, provides superior hemostasis(i) for patients and improved efficiencies to surgeons, nurses and facility administrations. The Ethicon Endo-Surgery Intraluminal Stapler (ILS), designed with a new tissue compression scale, provides surgeons improved flexibility and control so that they can address the individual needs of each patient. The products, which are the latest additions to the company's portfolio of solutions for colorectal surgery, will be featured at the Annual Meeting of the American Society of Colon and Rectal Surgeons (ASCRS), May 15-19, 2010 inMinneapolis.

Both surgical staplers were designed in collaboration with surgeons to be used in colorectal, bariatric and general procedures. The new products address the variability of tissue compression. Tissue compression—or the measurement of tissue density—prior to stapling is required with all surgical staplers to reliably deliver a staple line with proper staple formation. The optimal amount of compression is variable and affected by multiple factors such as the type, condition and thickness of targeted tissue. Tissue may vary in thickness and compressibility from patient to patient, as well as within an individual's GI tract. This variability extends to the amount of compression needed for effective hemostasis.

"The importance of stapling is a critical aspect of surgery that should not be underestimated. There are several variables that must be taken into account—sometimes during the procedure— in order to prevent post-surgical complications such as hemostasis," said Larry Sasaki, M.D.* at North Louisiana Surgery Center & Louisiana State University School of Medicine at Shreveport. "Advancements in stapling technology that secure tissue better and give surgeons the ability to make adjustments during the procedure based on varying tissue conditions is a welcome improvement over previous stapling instrumentation available for open surgery."

The EES Linear Cutter 55/75 (available in 55mm and 75mm lengths) employs an innovative and novel 3-D staple technology, which produces angled, parallel staple legs that overlap, unlike traditional surgical staples. In addition, the EES Linear Cutter 55/75 staples are deployed in a row of six instead of four. These innovations produce a unique staple line, delivering optimal tissue compression and superior hemostasis(i). The new EES Linear Cutter is also enhanced with:

• a single cartridge that contains three different staple heights, enabling surgeons to select staple height during surgery – based on the individual tissue thickness of the patient - without switching cartridges.
• an intermediate locking mechanism which allows for easier, one-handed tissue manipulation, allowing surgeons to gently interact with tissue.

Nanoscale features patterned on surfaces of polymer biomaterials can prevent blood clots

(Nanowerk News) Implanting artificial materials or devices in patients can cause adverse reactions when contacting natural tissue and blood. In blood-related defense mechanisms, plasma proteins quickly adsorb on the biomaterial surfaces and trigger a series of biochemical events that lead to platelet adhesion and aggregation into blood clots. The clotting can hinder the performance of an artificial device and can be life-threatening in some instances.

Now, Isabel Rodriguez from the Institute of Materials Research and Engineering of A*STAR, Singapore, and co-workers have discovered that adding miniature topographical features to polymer surfaces can reduce blood coagulation and improve the ‘hemocompatibility’, or blood compatibility, of biomaterials ("The effect of topography of polymer surfaces on platelet adhesion").

Using chemical modifications, many researchers have tried to coat or graft a secondary material to the surface of biomaterials to enhance their biocompatibility. Attempts to date, however, have met with limited success.

In many circumstances, secondary materials can leach out from the modified surfaces, which may have toxic effects, according to Rodriguez. “Hence, a biocompatible surface without additional chemical modifications is most desirable,” she says.

Fig. 1: Scanning electron micrograph showing that platelets adhere more to a planar surface (far left) than a nanostructured polymer surface (center, right).
To achieve this goal, Rodriguez and her team prepared various nano- and micro-structured surfaces from the biocompatible polymer poly(lactic-co-glycolic acid) (PLGA). They used alumina and silica templates prepared using nano- and micro-fabrication techniques to create nano- and micrometer-sized cavities. They then deposited PLGA solutions into these templates and cured them under vacuum to produce the structured polymer films.Next, the researchers incubated the surface-structured PLGA films with human fibrinogen—blood protein that mediates platelet adhesion and activation—and then with platelet-rich plasma. Finally, by quantifying fibrinogen, platelet adhesion and platelet activation, they assessed the ability of the films to promote blood clotting. Significantly fewer platelets adhered to surfaces covered with dense, high aspect ratio, nanometer-sized features than to planar surfaces (Fig. 1).From a comparison between a featureless PLGA film and an inert carbon surface, the researchers found that surface chemistry had an important role in the initial adsorption of proteins and platelets. However, appropriated surface features can overcome or complement the effect of chemistry and indeed reduce the tendency of blood clotting on an artificial surface, notes Rodriguez.“Surfaces with [a] high level of hemocompatibility will have important applications in surgical tools such as catheters and implantable medical devices like heart valves, stents or vascular grafts,” says Rodriguez. The team is currently planning to perform in vitro tests using whole blood samples, instead of just plasma, to assess clot size formation and clotting rate before moving on to in vivo tests.

Lawyer calls drug vials 'weapons of mass infection'

The drug companies that produced and sold the sedative linked to Southern Nevada's hepatitis C outbreak provided large vials of medication to endoscopy centers despite their risk to public safety, a lawyer charged Friday.

"These drug companies knew that these were weapons of mass infection. They knew what was going on in these endoscopy centers. ... They knew it for years and years and years, and they did nothing to stop it," Robert Eglet told a jury during closing arguments in the first trial stemming from the outbreak.

Eglet represents Henry Chanin, 62, who was infected with hepatitis C during a 2006 colonoscopy at the Desert Shadow Endoscopy Center, one of two clinics linked to Southern Nevada's hepatitis C outbreak.

Chanin, headmaster at The Meadows School, and his wife, Lorraine, are suing Teva Parenteral Medicine and Baxter Healthcare Services, which made and sold the drug propofol, on several product liability claims.

After hearing two weeks of trial testimony, the jury began deliberations late Friday afternoon to decide whether the companies should he held liable for Henry Chanin's infection.

His case was one of nine linked to two Las Vegas endoscopy clinics by health officials, who in 2008 notified 50,000 patients about possible exposure to hepatitis, HIV and other blood-borne diseases because of unsafe injection practices at the clinics. Hundreds of patients have filed lawsuits as a result of the outbreak.

Officials blamed the local outbreak on nurse anesthetists reusing single-dose drug vials between patients after the vials had become contaminated by the nurses reusing syringes on the same patient.

Eglet said the companies knew of the temptation to reuse the large 50 milliliter vials of propofol, which contained four to five times the amount needed for a typical 10-minute colonoscopy.

"They knew they were going to be 'double dipping' on this between patients," he said.

Teva and Baxter should have known about the dangers because propofol was associated with seven previous hepatitis C outbreaks that infected 148 people, he said.

Eglet also pointed to a report Teva wrote to the U.S. Food and Drug Administration in 2000 to get approval to make 10 milliliter vials of propofol. The report acknowledged that some medical workers were reusing the larger vials among patients to avoid throwing away unused anesthetic.

The smaller vials would improve patient safety undergoing endoscopic procedures because there would be less leftover anesthetic to tempt medical workers to reuse the vials, the report stated.

Teva made the 10 milliliter vials until 2007, when it stopped production in part because the smaller vials cost more to make than the larger vials, Teva executive Craig Lea testified at trial.

Based on their knowledge of previous misuse of the larger vials, the drug companies should be held liable because the misuse was "reasonably foreseeable," Eglet said.

The lawsuit originally named the doctor and nurses who performed Henry Chanin's colonoscopy, but their insurance company settled the medical malpractice claim last month, preventing the drug companies from shifting blame.

"They cannot point the finger at somebody who is not here," Eglet said.

The Chanins' suit also claims warning labels on propofol inadequately warned of the dangers of reusing the vials.

Drug company lawyer Mark Tully defended his clients, saying there was nothing defective about the propofol, which worked exactly as it was supposed to during Chanin's colonoscopy.

He said Teva made the 10 milliliter vials until 2007, when they were discontinued because doctors preferred to buy 20 and 50 milliliter vials. It was up to the medical professionals to decide which size was appropriate because the amount of propofol needed varies by procedure length and patient size, he said.

"There are uses for 20s and 50s that are entirely acceptable," Tully said.

He also dismissed the 148 hepatitis C cases Chanins' lawyers connected to propofol, pointing out that all of those infections were blamed on poor techniques for maintaining a sterile environment, such as reusing syringes and improperly cleaning scopes, which were warned against in the drug packaging.

"There are risks with using propofol, and the way to avoid those risks is to use proper aseptic technique and only use the vial on one patient," Tully said, noting that every propofol vial had "single-patient use" written in red letters.

Since being infected with the hepatitis C virus, which makes the liver swell and stops it from working correctly, Henry Chanin has lived with the constant worry of infecting his wife. The couple have stopped doing anything that might spread bodily fluids, from sharing a glass of wine to having sex. He also deals with lingering side effects of fatigue and joint pain two years after undergoing chemotherapy-like treatment for hepatitis C.

Eglet asked the jury to award him $8.5 million in damages to account for economic losses and his suffering. Lorraine Chanin's lawyer, Will Kemp, asked the jury to award her between $1.6 million and $2.3 million.

Eglet also encouraged the jury to levy punitive damages against the drug companies because of their conscious disregard for public safety in the name of profits.

"You can't put them in jail. We can't do other things," Eglet said. "The only thing we can do, quite frankly, is hit them where they take notice ... with money."

Egypt Bars Israeli Doctor from Int'l Conference in Cairo

Egypt has barred an Israeli hematology expert from attending an international conference set to take place this month in Cairo despite the longstanding peace treaty between the two nations.

Dr. Uri Seligsohn, Professor of Hematology at Tel HaShomer's Sheba Medical Center, has been unable to obtain a visa from the Egyptian government in order to attend the conference, scheduled for May 22-25. It was Seligsohn who had supported a decision to approve Cairo as the location for the meeting site, two years ago.

He is chairman of the Education Committee of the International Society on Thrombosis and Haemostasis (ISTH), the organization that is sponsoring its 56th Scientific and Standardization Committee (SSC) meeting, which he intended to attend.

The professor told the Hebrew-language Ma'ariv newspaper over the weekend that at the time, he “thought that there were ties of peace and friendship between Israel and Egypt,” and that “with the help of the conference we would be able to develop the Egyptian medical system – but unfortunately I was wrong.

“Apparently the Egyptians are uncomfortable that a Jew and an Israeli doctor should come to their conferences.

“Since it became known that the Egyptians refuse to approve my entry there has been a tremendous commotion among researchers and doctors around the world,” he said, according to IMRA (Independent Media Review and Analysis), which translated the report. “I know of many researchers who have canceled their attendance at the conference. The management of the organization has announced that this move will have serious ramifications for scientists in Egypt.” (IsraelNationalNews.com)

vCJD Families Protest outside Downing Street, London

The government has recorded 168 deaths due to variant CJD - caught from infected bovine material - but this figure is contested as being inaccurate by the families of victims because many of the families who have lost a loved one to this devastating brain disease say that they were never recorded in the official statistics.

Victims are also recorded as 'sporadic CJD', which was the original and very rare form of CJD that can occur in anybody and is not related to infected cattle.

Some cases, even in people in their teens and twenties, are put down to 'early onset alzheimer's disease'. Those left to nurse their husband's, son's, daughter's and wives through the terminal illness say that this is part of a cover up to protect pharmaceutical industries, who use bovine products widely in medicines and vaccines.

Unsafe Blood Donations

Eighteen UK blood donors later died of vCJD and their blood was used to make vaccines and medicines such as factor 8 which is given to haemophiliacs. Some haemophiliacs have since died of vCJD after being given infected blood. Despite this, the government refuse to screen donated blood. An effective test is available but they will not use it. Why not? Christine Lord, Grahame Bell and other members of the protest think it's maybe because screening people's blood would reveal the true magitude of the problem, which would be a disaster of epic proportions for government, the pharmaceutical and agricultural industries.

UK blood bags have warning labels on them due to being possibly contaminated with vCJD and they are not allowed for donation in any other country in the world apart from the UK.