To the best of our knowledge, only one study has ever used intraoperative IV TRA to reduce the amount of bleeding in prostatectomy.
Crescenti (
4) evaluated the effect of TRA on blood loss after prostatectomy in 200 patients and found that 34% of those in the TRA group and 55% of those in the control group received blood. According to the results, a 232 mL bleeding reduction was observed in the TRA group. These results are close to findings obtained from the current study. In other studies, topical TRA was used to control local bleeding. For example, the topical use of TRA was found to control bleeding in patients with bleeding disorders undergoing gynecologic surgery (
29). The effects of topical application of this drug was positively considered in reducing bleeding after tooth extraction in children with hemophilia and after orthopedic surgery (
25,
30). Fawzy found that the topical use of TRA in patients undergoing coronary artery bypass significantly led to low blood loss with no additional adverse effects (
31). Krohn et al. (
32) evaluated the effects of topical use of TRA on the amount of bleeding after lumbar vertebra fixation surgery and fibrinolysis of drainage blood in 30 patients. According to the results, the mean blood loss was reduced by half from 525 mL to 252 mL (P = 0.02) in the TRA group. Abrishami et al. (
33) found that the topical application of anti-fibrinolytic agents, particularly aprotinin or TRA, reduced the amount of bleeding in the first 24 hours after surgery and led to transfusion saving of one unit of isogroup blood for each patient. De Bonis showed that topical use of TRA (1 g of TRA diluted in 100 ml normal saline topically) in the pericardium after CABG (coronary artery bypass graft) in patients undergoing primary coronary artery bypass caused a significant reduction of postoperative bleeding compared with the placebo (
34). Similar results were obtained in the present and other studies.
Postoperative anemia is also a major problem that contributes to increased morbidity and mortality (
35) and prolonged hospitalization (
36). Previous studies showed that topical application of TRA decreased the post-operative blood hemoglobin reduction. Seo et al. (
36) reported that intravenous administration of TRA was more effective than its topical application in the prevention of blood hemoglobin reduction.
However, some studies produced opposite conclusions. Yasim et al. (
37) showed that applying topical aprotinin and TRA reduced postoperative bleeding during heart surgery, but this difference was not statistically significant Moreover, the difference between aprotinin and TRA in decreasing blood transfusion demand was not statistically significant.
The current study chose to evaluate TRA as recent studies have demonstrated that the local use of either TRA or aprotinin could practically decrease the rate of post-cardiac surgery bleeding. Although the strength of local administration of TRA has been observed to be the same as that of local administration of aprotinin in decreasing bleeding, the former is potentially more safer and inexpensive than the latter (
38). However, not all researchers agree on this finding (
37). Nevertheless, note that aprotinin may be more preferable to TRA in surgeries such as cardiac surgery, which has a high risk of bleeding (
27). TRA comprises small molecules (molecular weight 157 Daltons) that interfere with the connection point of lysine to plasminogen and their product of transforming to plasmin. It exclusively prevents plasmin from accessing fibrin and has no other direct effect on hemostasis. Conversely, aprotinin, which is a non-exclusive serine inhibitor, directly inhibits plasmin in low density and makes the contact phase of the inner route of hemostasis easy in high density, thus resulting to minimal anti-coagulation effects (
38). In the mechanism of the local administration of TRA, a 150% increase was observed in the density of plasmin/alpha 2-antiplasmin and D-dimer in the drainage blood of the TRA group 1 hour after surgery. The increase was 320% and 260% in the observed group, respectively. No side effects were reported in the local use of this type of medicine. Eventually, the local use of antifibrinolytic was concluded to reduce post-surgery bleeding and the necessity for blood transfusion in patients undergoing on-pump cardiac surgery (
31). A new meta-analysis on the use of transamin for decreasing bleeding volume was published (
39). In this study, platelet and coagulation disorders simultaneously affect the whole bleeding volume. For instance, hypotensive anesthesia, correct position of the patient and patient volume correction greatly affect the decreasing waste bleeding, which needs to be evaluated in future studies.