Not every bleeding surface in surgery is flat. Resected organ beds, irregular bone defects, and uneven parenchymal surfaces present a shape problem that sheet-based hemostatic materials cannot always solve well. A flowable hemostatic matrix addresses this by taking a paste- or putty-like form that can be manually shaped or injected into contours before it sets, conforming to the wound rather than the other way around.
This article explains what a flowable hemostatic matrix generally consists of, how it is applied, and where it is commonly used in surgical practice.
What Is a Flowable Hemostatic Matrix Made Of?
Most flowable hemostatic matrices on the market combine two components: a gelatin-based substrate, often in granular or particulate form, and a thrombin component that activates the clotting cascade at the application site. When mixed, typically by the surgical team just before use, the two components form a moldable paste that can be applied directly into or onto an irregular wound bed. Because the gelatin base is absorbable, the material is generally intended to remain at the site temporarily while supporting hemostasis, before being resorbed by the body over time.
How Does a Flowable Matrix Actually Achieve Hemostasis?
The hemostatic effect of a flowable matrix relies on two mechanisms working together. First, the gelatin particles provide a physical scaffold that fills the irregular defect and creates surface area for platelets and clotting factors to interact with. Second, the thrombin component directly participates in the clotting cascade, converting fibrinogen present in the patient's own blood into fibrin — the structural protein that forms the mesh of a stable clot. Because thrombin acts on the patient's own fibrinogen, effective use generally depends on the patient having adequate circulating clotting factors, which is one reason underlying coagulation status is considered relevant by treating clinicians when selecting a hemostatic approach.
When Do Surgical Teams Reach for a Flowable Matrix Instead of a Sheet-Based Hemostat?
Because a flowable matrix can be shaped by hand or applied through an application device into a defect, it is generally favored over sheet or fabric-based hemostats when the bleeding surface itself is irregular — for example, a resection bed in solid organ surgery, an uneven cut bone surface, or a cavity remaining after removal of tissue. Sheet-based materials such as oxidized regenerated cellulose, by comparison, tend to be favored on broader, flatter oozing surfaces where a fabric-like layer can be draped evenly. Neither format is considered universally preferable; the selection is generally driven by the physical geometry of the bleeding site and the surgeon's assessment during the procedure.
What Should Be Considered Before Using a Flowable Matrix?
Several general considerations are commonly discussed in relation to this hemostat category. The area should generally be as free of excess pooled blood as reasonably possible before application, since a flowable matrix is intended to support clotting at the surface rather than to be used as a substitute for controlling brisk, active bleeding through direct surgical means. The product is also typically intended for topical application onto a bleeding surface rather than for injection into the vascular system, and manufacturer Instructions for Use (IFU) should always be consulted for specific handling, mixing, and application guidance, since formulations and application devices vary between manufacturers.
How Does Absorption Work for This Type of Hemostat?
Because the gelatin component of a flowable matrix is absorbable, the material remaining at the application site is generally expected to be resorbed by the body over a period of time following surgery, similar in principle to other absorbable hemostatic categories such as oxidized regenerated cellulose. Exact absorption timeframes vary by specific product formulation, amount used, and individual patient healing factors, so general assumptions about absorption speed should not substitute for the specific product's labeling.
What makes a flowable hemostatic matrix different from a hemostatic sheet or pad?
The key difference is physical form and how each conforms to the wound. A flowable matrix is a moldable paste that can be shaped into irregular or cavity-like defects, while sheet-based hemostats are generally better suited to broader, flatter surfaces where a fabric-like layer can be laid across the area evenly.
Does a flowable hemostatic matrix work without the patient's own blood components?
Generally, no. The thrombin component of a flowable matrix converts the patient's own circulating fibrinogen into fibrin as part of the clotting process, so its hemostatic effect depends in part on the patient having adequate underlying clotting function. This is a general consideration a treating clinician takes into account rather than an individual guarantee of effectiveness.
Is a flowable hemostatic matrix left in the body permanently?
No, this category is generally designed to be absorbable over time as part of normal healing, rather than to remain permanently. Specific absorption timeframes vary by product and should be confirmed through the manufacturer's Instructions for Use (IFU).
Flowable hemostatic matrices represent one of several agent categories within INVAMED's hemostatic tissue sealant solutions portfolio, which spans absorbable hemostats, sealant systems, and tissue adhesives suited to different surgical bleeding patterns across specialties.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.