A keratin biomaterial gel hemostat derived from human hair: evaluation in a rabbit model of lethal liver injury.

Abstract

Effective hemostatic dressings that are compatible with tissues are needed. Keratins are a class of biomaterials that can be derived by extraction of proteins from human hair. We have recently discovered that keratin biomaterials have hemostatic characteristics and hypothesize that a keratin hydrogel having the ability to absorb fluid and bind cells may be an effective hemostat. The goal of this study was to test a keratin hydrogel and evaluate it compared to current hemostats. Thirty-two New Zealand white rabbits received a lethal liver injury. Eight animals each were assigned to negative control, QuickClot, HemCon bandage, and keratin treatment groups. Vital stats and other data were recorded during surgery and all surviving animals were sacrificed after 72 h. Histology was conducted on all surviving animals. Twenty-four-hour survival rates were 0%, 62.5%, 62.5%, and 75% for the negative control, QuickClot, HemCon, and keratin groups, respectively. Other outcomes included blood loss, mean arterial pressure, heart rate, shock index, and liver histology. All of the hemostats were statistically better than the negative control group at late operative time points. The keratin group consistently performed as well as, or better than, the commercial hemostats. Histology showed an interesting healing response at the hemostat-liver interface in the keratin group.

Surgeons get tips and tricks for contending with antiplatelet therapy

Lisbon, Portugal - A session on the best practice for operating on patients taking antiplatelet therapies was well received at the European Association for Cardio-Thoracic Surgery (EACTS) 2011 Annual Meeting this week, with attendees saying they welcomed advice on this topic in light of the newer antiplatelet agents coming onto the market.
Surgeons generally want to stop antiplatelet therapy several days before an operation to reduce bleeding risk, but this can have a negative impact in terms of thrombotic events, particularly if a patient has recently had a drug-eluting stent (DES) placed. And while there are recommendations for when to stop antiplatelet therapy prior to surgery—generally advised at five days beforehand for clopidogrel, three days for ticagrelor, and seven days for prasugrel—"the reality is that very often we have to proceed with surgery much faster," surgeon Dr A Pieter Kappetein (Erasmus Medical Center, Rotterdam, the Netherlands) told the meeting.

Cardiologist Dr Freek Verheugt (Onze Lieve Vrouwe Gasthuis, Amsterdam, the Netherlands) acknowledged that "the eternal difficulty for the surgeon is balancing the risks of bleeding and thrombosis," in a sentiment that was echoed in another talk on "tips and tricks for operating under antiplatelet therapy," given by Dr Miguel Sousa Uva (Hospital da Cruz Vermelha Portuguesa, Lisbon).

Both Verheught and Sousa Uva stressed that the key to determining what to do about dual antiplatelet therapy in the face of surgery is to use individual risk assessment, on a case-by-case basis, and they advised using an algorithm to aid in this decision, taken from the latest European guidelines on revascularization.

Following the session, cochair Dr Jose Luis Pomar (Hospital Clinico de Barcelona, Spain) observed: "This is a very interesting topic. After this, I believe we are still ignorant, but perhaps we have a bit more understanding than before."

Fibrinogen and Hemostasis: A Primary Hemostatic Target for the Management of Acquired Bleeding

Jerrold H. Levy, MD, FAHA,
Fania Szlam, MMSc,
Kenichi A. Tanaka, MDand
Roman M. Sniecienski, MD

+Author Affiliations
From the Department of Anesthesiology, Emory University School of Medicine, Cardiothoracic Anesthesiology and Critical Care, Emory Healthcare, Atlanta, Georgia.
Address correspondence to Jerrold H. Levy, MD, FAHA, Department of Anesthesiology, Emory University School of Medicine, Cardiothoracic Anesthesiology and Critical Care, Emory Healthcare, Atlanta, GA.

Abstract

Fibrinogen plays several key roles in the maintenance of hemostasis. Its cleavage by thrombin and subsequent polymerization to form fibrin strands provides the structural network required for effective clot formation. During cases of acute blood loss, attempts to maintain circulating volume and tissue perfusion often involve the infusion of crystalloids, colloids, and red blood cells. Intravascular volume resuscitation, although vital, frequently results in dilution of the remaining clotting factors and onset of dilutional coagulopathy. In such cases, fibrinogen is the first coagulation factor to decrease to critically low levels. There currently is a lack of awareness among physicians regarding the significance of fibrinogen during acute bleeding and, at many centers, fibrinogen is not monitored routinely during treatment. We reviewed current studies that demonstrate the importance of considering fibrinogen replacement during the treatment of acquired bleeding across clinical settings. If depleted, the supplementation of fibrinogen is key for the rescue and maintenance of hemostatic function; however, the threshold at which such intervention should be triggered is currently poorly defined. Although traditionally performed via administration of fresh frozen plasma or cryoprecipitate, the use of lyophilized fibrinogen (concentrate) is becoming more prevalent in some countries. Recent reports relating to the efficacy of fibrinogen concentrate suggest that it is a viable alternative to traditional hemostatic approaches, which should be considered. The prospective study of fibrinogen supplementation in acquired bleeding is needed to accurately assess the range of clinical settings in which this management strategy is appropriate, the most effective method of supplementation and a comprehensive safety profile of fibrinogen concentrate used for such an approach.
Accepted July 11, 2011.

Study: Kids Given Plasma Despite No Clear Benefit

Many kids get plasma transfusions when there's little evidence they do much good, according to a new study.
Transfusions of so-called fresh frozen plasma are sometimes given to both kids and adults whose blood has problems clotting, or if they have lost a lot of blood from surgery or an accident.
But only a couple of studies in kids have shown that plasma transfusions are a good option for one specific heart surgery procedure. The rest of the time, researchers have found they don't work, or that their benefit is uncertain.
In the current study, pediatricians reported that almost three percent of kids admitted to children's hospitals in the U.S. had a transfusion. More than half of the transfusion recipients were under a year old, a third had heart disease and 70 percent were critically ill.
"For all we know, it may be used entirely appropriately," said Dr. John Puetz, from Saint Louis University, who worked on the study.
"The problem is, we don't have the evidence base... to demonstrate what's inappropriate use and what's not inappropriate use."
"The concern," he told Reuters Health, "is a fair number of children are being exposed to (fresh frozen plasma) without published data showing what it's effective for."
The problem with that, researchers said, is that the transfusions always come with a risk of side effects and complications, which range from allergic reactions to heart failure, if doctors give kids more plasma than their hearts can handle.
Puetz's team consulted a database of about 3.2 million admissions to 40 different children's hospitals in the last decade. According to hospital records, just under three percent of those kids got a plasma transfusion, most in the intensive care unit.
The researchers couldn't tell why the plasma was used in each case, or how much of it kids got. But only about one-third of the kids' records also showed they had a heart procedure known as a cardiopulmonary bypass -- when a pump does the job of the heart and lungs during surgery, and a plasma transfusion (along with red blood cells) is indicated.
There were 24 recorded cases of acute lung injuries related to the transfusions, but the authors write in the Journal of Pediatrics that it's hard to tell how many kids had other complications.
"The biggest reason not to give any transfusion... is the risk of the complications that you can have," said Dr. Lorne Holland, of the Nashville-based pathology services company PathGroup, Inc., who has researched the use of fresh frozen plasma. That would include lung injuries and congestive heart failure, as well as more minor itchy allergic reactions.
Still, Puetz added, "No one's really looked to see what all the possible side effects may be."
A typical plasma transfusion would cost a few hundred dollars, Holland said.
He thinks that too many kids are still getting the transfusions, despite the general lack of evidence that they work -- or are better than other alternatives such as whole-blood transfusions in certain cases.
"I think the numbers in that study and ones in adults are too high," Holland, who was not involved in the study, told Reuters Health. "A lot of physicians are convinced by evidence of, 'That one patient, that one time, seemed to do better when I gave it to them.'"
Puetz said it's still not clear whether plasma transfusions are being done too often, based on the lack of data. He called for more critical studies to see if fresh frozen plasma transfusions really do work in all of the cases where they're commonly used in kids.

Scientists Use Stem Cells for Blood 'Self-Transfusion'

Researchers report that they used stem cells to create cultured red blood cells and then successfully injected the blood cells back into the human donor who provided the stem cells in the first place.
The findings raise the possibility of creating individualized blood supplies without making people donate their own blood for storage before they need a transfusion, a potentially dicey situation if someone is ill.
The researchers said that the cultured red blood cells created with the help of stem cells from the donor -- and then inserted back into the donor -- lived about as long as regular blood cells normally do.
The study, the first to show that red blood cells created from stem cells can survive in the human body, is "a major breakthrough for the transplant community," Dr. Luc Douay, senior study author and a professor of hematology at Universite Pierre et Marie Curie in Paris, said in a news release from the American Society of Hematology.
"There is a dire need for an alternative source of transfusable blood products, especially with the risk of infection from emergent new viruses that comes with traditional transfusion," Douay explained. "Producing red blood cells in culture is promising since other efforts to create alternative sources have not yet been as successful as once hoped."
However, one expert said the research isn't quite as exciting as it may sound.
Creating red blood cells from your own stem cells is "going to be an extremely complex process, extremely expensive, not very convenient and uncommonly used," explained Dr. Paul Holland, a blood banking specialist and a clinical professor of medicine and pathology at the University of California, Davis Medical Center.
"Most people who need a transfusion need it now, and they use blood from donors that's already there," he said. One exception might be if someone has a condition that makes it difficult to match his or her blood to other donors and it's dangerous to draw and save their own blood, he said.
The findings appear in the Sept. 1 issue of the journal Blood.

Cook Endoscopy Recalls Disposable Hemostasis Clips for Gastroenterologists

Cook Endoscopy is recalling its Disposable Hemostasis Clip, DCH-7-230, according to a Total Recall report.

The company warned that the disposable clip may not deploy after being positioned inside the patient.

The device is used for endoscopic marking, hemostasis for mucosal sub-mucosal defects less than 3cm in the upper GI tract, bleeding ulcers, arteries less than 2 mm wide and polyps less than 1.5 cm in diameter in the GI tract.

Baxter Announces FDA Approval of ARTISS Fibrin Sealant for Use in Face-Lift (Facial Rhytidectomy) Procedures

DEERFIELD, Ill., Aug 31, 2011 (BUSINESS WIRE) -- Baxter International Inc. announced today that the U.S. Food and Drug Administration (FDA) has expanded the indication of ARTISS [Fibrin Sealant (Human)] to include adhering tissue flaps during facial rhytidectomy surgery (face-lift). ARTISS is the only premixed, ready-to-use fibrin sealant specifically indicated for tissue adherence in facial rhytidectomy (face-lift) and burn surgeries. It was first approved by the FDA in 2008 to adhere autologous skin grafts to surgically prepared wound beds resulting from burns in adult and pediatric populations one year of age or older.

Baxter Acquires Ostene

August 17, 2011
Ceremed, Inc. (Los Angeles) announced today that it has entered into a definitive agreement to sell its Ostene® brand bone hemostasis product line to Baxter International Inc. The agreement provides for Baxter to acquire all rights to the Ostene® brand, including manufacturing.
Founded in 2002, Ceremed is a privately held medical device company focusing on the design and development of medical materials, utilizing their proprietary AOC PolymerBlend™ technology. Ceremed has successfully commercialized applications ranging from coatings and carriers to bone hemostasis. Based on the proven safety, efficacy and versatility of the AOC PolymerBlend™ technology, Ceremed looks forward to the continued development and innovation of products that meet the needs of today’s surgeons.
“We are very pleased that Baxter has agreed to acquire the Ostene® brand.” said Tadeusz Wellisz, M.D., chairman of Ceremed.
With the divestiture of both the marketing and manufacturing of Ostene®, Ceremed will free up assets needed to focus on bringing new products to market that will meet the demands of patients and device manufacturers alike. “This is a great opportunity for Ceremed to take the next step to becoming a major player in the biomaterials market,” noted Bill Lamm, president of Ceremed.

EDQM Launches New Web Page On Blood Transfusion Projects

The European Directorate for the Quality of Medicines & HealthCare (EDQM) has launched a new web page highlighting its various projects in the area of blood transfusion. The page covers the growing number of important activities in this field.
The web page is designed to be a centralised forum to share information about ongoing projects. It includes details of the progress of each project, press releases, news updates on new or planned projects, relevant resolutions, the terms of reference of the different project groups, as well as links to other organisations working in this area. In addition, it lists the European Committee on Blood Transfusion (CD-P-TS) members.
Importantly, the new web page also serves as an information portal for 'Project TS057: Risk Behaviours having an impact on Blood Donor Management and Transfusion Safety'. Exclusion criteria for blood donors, especially with regard to sexual behaviours, are much debated. The present situation, involving the permanent exclusion of individuals whose behaviour places them at higher risks of acquiring severe infectious diseases that are transmissible by blood transfusion, is being questioned by citizens and by the press in terms of whether this kind of donor deferral is legal, right, appropriate, efficient and required.
Despite the testing of blood donations with highly sensitive test systems, there remains a residual risk of transfusion-transmitted infection due to donations given in the 'window' period, i.e. the time period between initial infection and its detection. This is not always recognised by the public.
As a consequence, the CD-P-TS of the EDQM, Council of Europe has appointed a working group (TS057) to monitor current practices, evaluate the scientific data and define a harmonised approach to establishing rules for donor deferral, linked to the risks attributable to sexual behaviour. The group started its work in February 2010 and will finish during autumn 2011.

http://www.edqm.eu/en/Whats-new-525.html

Patients who undergo bowel surgery face a postcode lottery of care, research suggests.

In some parts of the country, those who are operated on at much higher risk of needing further treatment to stop bleeding or correct complications.
Academics found a fivefold difference in reoperation rates in NHS hospitals for planned bowel surgery.
It comes after a landmark study showed that bowel cancer sufferers in some parts of the country after almost 10 times as likely to die after surgery for the disease.
Researchers at Imperial College London conclude, in a paper published online at Bmj.com, that figures for the number of repeat operations could be used to compare quality alongside death rates for a range of types of surgery.
They write: “This study supports the feasibility of using reoperation rate as a quality indicator derived from routinely collected data.
“If data accuracy can be assured, this methodology may permit national performance assessment using reoperation alongside other indicators such as mortality and will be easily transferable across a range of surgical specialties.
“Initiatives to improve surgical performance should be focused on reducing inexplicable observed variation in reoperation after major resectional colorectal surgery.”
The team used Hospital Episode Statistics to look at the experiences of 246,469 patients in 175 English hospitals who underwent colorectal surgery between 2000 and 2008.
They found that in total, 15,986 needed further surgery (6.5 per cent of the total) within 28 days of the original operation, mainly to stop “postoperative bleeding” or a breakage that leads to the leak of gastric or intestinal fluid.
Emergency patients and men were slightly more likely to need extra procedures, as were those who had inflammatory bowel disease.
But the researchers also found “considerable variation” between individual surgeons and NHS trusts in their reoperation rates.
Some hospitals reported no reoperations but others had rates of 17 per cent.
The reoperation rate was five times as high for planned surgery in the highest-performing hospitals compared with the lowest (14.9 per cent compared with 2.8 per cent), among those that performed more than 500 procedures.
In a comment piece, Arden Morris, Associate Professor of Surgery at the University of Michigan, says that measuring quality is only the first step in the more important goal of improving quality.
She warns that forcing hospitals to publish their reoperation rates will not necessarily help, and that proposals to improve patient care are also needed.
“Policy interventions that do not deal with underlying mechanisms are not likely to improve outcomes. Instead, they may perversely contribute to tension between quality measurement and quality improvement.
“For example, a call for mandatory reporting of reoperation rates is unlikely to result in a change in surgical technique but could increase rote paperwork and even cynicism among providers.”