Keeping Blood Where It Belongs
Since the AIDS epidemic of the 1980’s there has been a prevalent public fear of infection from blood transfusions, and the requests for bloodless surgeries have been on the rise in recent years not just from religious objectors to transfusions, but also from those simply seeking peace of mind. Adding to this fear is the increasing evidence that, despite popular opinion, blood transfusions do not always improve surgery outcomes. A recent study led by the Virginia Commonwealth University Medical Center showed that patients who received platelet transfusions during coronary bypass surgery were more likely to require longer hospital stays and bore a greater risk of infection, post-operative bleeding, stroke and death.
While autologous blood transfusions have been increasing in popularity and, in the process, improving patient outcomes and stress levels, it still involves putting outside blood into the patient. Thus, the risk of infection, though minimized, is still there. Basically, the best way to avoid the potential risks of blood transfusions is to avoid the transfusions all together, and the best was to accomplish this is to conserve the patient’s blood throughout the surgery.
Of course, this is easier said then done. In minor procedures blood loss poses little concern, but in major surgical procedures and many open procedures blood loss is inevitable. There are, naturally, traditional techniques utilized to stop bleeding. Pressure can be applied to bleeding areas to quell the flow, clamps can be affixed to veins and arteries, and tourniquets can be used restrict to flow of blood to limbs and appendages. These techniques are effective, but not always practical or possible in some surgeries.
Advances in medical science over the past few decades have ushered in other tools and technologies to help stop intraoperative bleeding, and provided surgeons with a choice of the most effective surgical hemostasis technique for each procedure. Electrosurgery and electrocautery allow surgeons to coagulate blood and cauterize vessels and capillaries, while tissue adhesives function as sealants that either promote clotting or enhance the effectiveness of ligatures.
But while advancing technology can provide newer and more effective ways to solve problems during surgery, it can also bring further complications. With the increasing prevalence of minimally invasive surgery, and its benefits ensuring its continuing popularity, surgical hemostasis is becoming harder to achieve. While it must be granted that the minimally invasive approach, by its nature, reduces bleeding, any blood loss that does occur is entirely internal. Suction can be used to keep to surgical site relatively clear, but even the smallest amount of blood entering the site can seriously affect the surgeon’s visibility.
Naturally, though, there are already certain products available to help surgeons stop bleeding in hard to reach areas where ligature and traditional means of hemostasis are impeded or ineffective.
Avitene Flour is indicated for all surgical procedures, including neurosurgery and urology. Effective in controlling arterial bleeding, it conforms and adheres to irregular spaces, making it invaluable in such cases where use of ligatures or conventional methods of hemostasis are ineffective. The hemostat can then be easily removed with irrigation and suction. The Avitene Sheet, a non-woven web, has the same properties and efficiency as the Avitene Flour, but comes in three sizes allowing it to be cut into any shape or size required. The configuration of the Sheets makes them ideal for use on flat surfaces, but they can also be used to wrap vessels. To further assist in the effective placement of the Avitene hemostats, Davol offers two delivery units specially configured to accommodate a wide variety of surgical procedures. The SyringeAvitene Collagen Hemostat provides Avitene Flour in an easy to handle applicator that allows the user to apply as little or as much of the hemostat as required. The one gram SyringeAvitene can be used in general surgery, oncology, cardiovascular procedures, and in trauma cases, while the 5-mm SyringeAvitene is designed to deliver Avitene Sheets to hard to reach areas. This model comes in especially handy in Neuro and ENT surgeries.
Davol’s hemostasis product line also includes The Avitene Ultrafoam Collagen Sponge, a soft and pliable hemostasis sponge that is ready-to-use right out of the package without any need for soaking, and the Avitene UltraWrap Collagen Hemostat, an active, absorbable, easy-to-handle collagen fabric that requires no preparation and will not swell after application.
Another offering for intraoperative hemostasis is CryoLife, Inc.’s BioGlue®, a surgical sealant cleared for use as an adjunct to standard methods of achieving hemostasis. “BioGlue is indicated for cardiac and vascular surgery, for large vessel repair including carotids, femorals and aorta, and for tissue reinforcements such as aortic dissections,” says Adam Silver, Marketing Manager, Global Bioadhesives at CryoLife. “Though it is being used off label.”
BioGlue is a two-component adhesive composed of purified bovine serum albumin (BSA) and glutaraldehyde. The solutions are mixed during application from a controlled delivery system. The glutaraldehyde then cross-links the BSA molecules to each other and then to the tissue protein at the repair site. The BioGlue polymerizes within 20 to 30 seconds and reaches its full bonding strength within two minutes.
The original controlled delivery system designed for BioGlue is composed of a reusable delivery device, applicator tips, and applicator tip extenders. BioGlue cartridges, which contain the BSA and glutaraldehyde components are simply inserted into the delivery system and are ready to use. The cartridges are available in 2-ml, 5-ml, and 10-ml sizes, require no preparation, and boast a shelf life of three years when stored at room temperature.
A new delivery system for BioGlue was recently introduced that requires even less set up than the original controlled delivery system. The BioGlue Syringe comes in an all inclusive package that contains five pre-filled syringes, tips, and plungers. They are quick to set up, easy to use, and fully disposable. Available in 5-ml and 2-ml sizes, they provide a simple, off-the-shelf hemostasis solution.
Fibrin SealantsOver the past few years fibrin sealants have been gaining popularity for intraoperative hemostasis in operating rooms across the United States. Using actual human proteins, fibrin sealants react with human tissue to promote natural coagulation and clotting.
CROSSEAL is derived from human blood plasma and contains the coagulation factors necessary to stop bleeding in surgical settings. It is totally free of bovine components, making it useable by a wider number of patients. This fibrin sealant delivers its active components in a simple, easy-to-use proprietary pre-assembled applicator device that can be used for both dripping and spraying. Shipped frozen, CROSSEAL can be available in one minute when thawed and requires no reconstitution, special heating, or stirring devices. It is stable for up to 24 hours at room temperature and, unopened, can be refrigerated for up to 30 days.
Baxter’s Tisseel VH Fibrin Sealant has the maximum concentration of human fibrinogen to stimulate this natural physiologic clotting process. Tisseel firmly adheres to connective tissue and forms an easy-to-see clot that aids in surgical trimming. It also has a high level of elasticity for application to pulsating, moving organs. Also available is Tisseel VH Fibrin Sealant Biologic-Only, a configuration that does not include any reconstitution or delivery devices, for a more efficient ordering process.
While this is just a brief overview of some of the more popular hemostasis products currently available to surgeons, they represent the front line in hemostasis technology. With some of these hemostats still in their infancy, it seems safe to assume that they will continue to develop as surgery itself so rapidly is.