This study was designed as a prospective, randomized study to compare CHM with a commonly used hemostatic agent, GHM, during CABG. Active flowable hemostatic matrices (CHM or GHM) contain thrombin and a particulate carrier in a single application product. These products work by blocking blood flow and actively converting blood fibrinogen into fibrin at the site of bleeding.13,14 In our study, the two groups receiving active, flowable hemostatic agents were compared to assess the hemostatic effect, and the results were similar between the groups. Furthermore, the CHM group demonstrated a reduction in the rate of required RBC, FFP and platelet transfusions. These findings suggest a potential efficacy of CHM for achieving hemostasis during CABG.
Several prospective, randomized, controlled trials across numerous surgical areas have reported an active, flowable hemostatic matrix (GHM) to be a more effective hemostat, demonstrating faster hemostasis and better outcomes, than passive, non-flowable hemostatic agents (e.g., Gelfoam® an absorbable gelatin sponge, The Upjohn Co. Kalamazoo, MI, USA; Surgicel®, an oxidized regenerated cellulose, Jonson & Johnson Products, Inc, New Brunswick, NJ, USA).15,16 Some of these studies also indicate that the use of an active, flowable hemostatic matrix is associated with fewer post-surgical complications and shorter surgical times compared to other common, passive, topical hemostats.17,18 In our study, both CHM and GHM showed complete cessation of bleeding within 4 min of application at aortocoronary anastomoses sites and few post-surgical complications.
Few studies have compared the clinical performance and outcomes of active, flowable, topical hemostatic matrices in cardiac surgery.19,20 Two studies compared GHM and Surgiflo® (thrombin-gelatin hemostatic matrix; Ethicon, Somerville, USA) in a porcine model and reported that GHM stopped bleeding more effectively than Surgiflo®. 21,22 Scott et al. analyzed why GHM was associated with fewer negative outcomes than Surgiflo®.17 These revealed that the performance differences of these active, flowable hemostats may be due to the composition of the gelatin granules. However, in our study, gelatin granule characteristics, such as a porcine (CHM) versus a bovine (GHM) source, did not contribute to differences in efficacy.
Topical hemostatic agents may provide an economic advantage. Given the high cost associated with blood transfusion and its impact on hospital resources, the use of effective hemostats may be associated with potential cost savings due to reductions in transfusions.23–24 Although our study did not include a formal cost-utility and cost-efficacy analysis, we applied equal volumes (5 ml) in the two groups to increase comparability. In a tertiary-care hospital, CHM costs 40 USD per 1 ml, and GHM costs 80 USD per 1 ml. Thus, if CHM shows the same hemostatic effect as GHM, it may be more cost effective. Furthermore, collagen, one of the main ingredients of CHM, is one of the primary extracellular proteins in animal tissues, allowing for easy extraction and purification. Moreover, it provides an environment for fibroblast formation and induces wound healing by inactivating elastase and matrix metalloproteases.
The available topical hemostatic agents have demonstrated variable efficacy, may require significant preparation time, and provide limited benefit in diffuse, aggressive or difficult-to-access bleeding sites. However, CHM can easily and quickly access bleeding sites due to its flowable nature and short preparation time of less than 20 s. These strengths can be applied in the surgical field.
Our study includes some limitations. First, we had a small sample size. This fact may have led to a type II error, slightly narrowing the generalizability of the results found. Given the lack of clear differences between the two groups for ITT analysis, a larger number of patients is needed to evaluate the hemostatic superiority of both agents. Second, we did not conduct preoperative point of care testing for coagulopathy analysis. Third, this study had a short follow-up period; thus, the influence of the hemostats on the long-term clinical outcomes should be further evaluated. Lastly, we didn’t perform cost analysis in our trial, since this was not the focus of this research. It is known that CHM presents lower costs compared to GHM. We could say that in the future, it would be important to study our intervention with a bigger sample size and longer follow-up.