Gender affirming surgeries (GAS) have been steadily increasing in the US, with the gender affirming mastectomy (GAM) being the most common surgery performed. Complications associated with these surgeries include hematoma and seroma. Prior studies in orthopedics, plastic surgery, and trauma have shown significant reduction of bleeding and ecchymosis with the use of tranexamic acid (TXA). TXA is a synthetic amino acid that blocks plasminogen conversion to plasmin, to stabilize clot formation. The intravenous (IV) efficacy in reducing hematoma rates has been established in implant-based breast reconstruction, as well as in reduction mammaplasty. However, there are currently no studies investigating the use of IV TXA in patients undergoing GAM.

The investigators propose a single-center, prospective randomized control trial to evaluate the efficacy and safety of intravenous tranexamic acid in decreasing hematoma and seroma rates for top surgery patients at UCSF. Patients will be randomized into two groups, an experimental group receiving IV TXA and a control group that will not receive IV TXA.

Patients in the experimental group will receive a loading dose of tranexamic acid (TXA) at a concentration of 1g/10ml over a period of 10 minutes, administered immediately following anesthesia induction. Patients will be excluded if they have a history of coagulopathy, bleeding disorders or prior chest surgery. Demographic data, surgical characteristics, and postoperative outcomes will also be recorded and analyzed. The investigators hypothesize that the use of IV TXA will significantly reduce hematoma, seroma, postoperative drain output, and time to drain removal in patients undergoing GAM.

Aim 1: To evaluate the effectiveness of IV TXA in reducing intraoperative bleeding, post-operative hematoma and seroma formation, drain output, and time to drain removal in patients undergoing GAM.

Aim 2: To compare the incidence of thromboembolic events and wound complications between patients receiving IV TXA and those who do not after GAM.

This is a prospective, randomized, controlled single-surgeon trial performed at the University of California San Francisco that investigates the use of IV TXA in patients undergoing GAM. All patients who meet WPATH guidelines for GAM, undergo GAM, ASA I-III, and are >18 years old will have the opportunity to be enrolled. Patients will be randomized by a random computer generator and will be notified after randomization as to which group they are assigned.

The investigators will enroll patients into this prospective trial investigating the effect of IV TXA on postoperative bleeding, hematoma, seroma, drain output, and time to drain removal. Patients will be randomized into two groups, an experimental group receiving IV TXA and a control group that will not receive IV TXA. Patients will be excluded if they are <18 years old, have a history of prior chest surgeries, coagulopathy or bleeding disorders, and have a history of thromboembolic events including deep vein thrombosis or pulmonary embolism. Patients will also be excluded if they are chronically anticoagulated, are on antiplatelet medications or have ever had an adverse reaction to IV TXA.

All patients who are being scheduled to undergo bilateral mastectomy with immediate reconstruction will be recruited to participate in the study. Patients will be consented to participate in the preoperative visit.

Experimental Group: Patients in the experimental group will receive a loading dose of tranexamic acid (TXA) at a concentration of 1g/10ml over a period of 10 minutes, administered immediately following anesthesia induction. Postoperative care will be standard and based on established UCSF guidelines.

Control Group: Patients in the control group will not receive any TXA intraoperatively and will undergo a traditional GAM.

Tranexamic Acid is available as a sterile, single-dose. This 1g vial is readily available in the anesthesia cart in the operating room. Immediately following induction, the anesthesia team will administer 1g of TXA intravenously. After obtaining hemostasis and irrigating as per standard practice, anesthesia shall not use any other hemostatic agents.

Post-procedure, each patient will be provided with standard postoperative instructions which will include a chart to record daily drain outputs for the right and left sides. At subsequent postoperative visits, drain output will be assessed at each clinic visit to determine timing for removal. The total drain output will be measured by the patient and later logged into our chart for later analysis. Drains will be removed per standard practice at our institution which is when they have produced < 30cc/day for at least 3 days.

At each clinic visit, the investigators will assess for clinical signs of hematoma and seroma, and objectively measure aggregate drain output. Demographic data, surgical characteristics, and postoperative outcomes such as hematoma, seroma, drain output, wound complications, surgical site infections, and thromboembolic events will be recorded and analyzed. These outcomes will be evaluated in the immediate 3-month postoperative period, with a 1-year follow-up review of patient charts. The primary outcomes will include the presence of hematoma, seroma, and drain output, and time to drain removal, while the secondary outcomes will consist of thromboembolic events and wound complications.

Patients will be managed for hematoma and seroma as per standard procedure, whether with ultrasound, clinic aspiration, IR drain placement, or return to the operating room as deemed necessary by the senior surgeon.

Inclusion Criteria:

1. Age ≥ 18 years of age
2. All patients who undergo gender affirming mastectomy at UCSF
3. ASA I-III,
4. Ability to understand a written informed consent document, and the willingness to sign it.
5. Patients who fulfil WPATH guidelines/criteria for undergoing GAM. WPATH Criteria include: Persistent, well-documented gender dysphoria; capacity to make a fully informed decision and to consent for treatment; age of majority in a given country; if significant medical or mental health concerns are present, they must be reasonably well controlled; 12 continuous months of hormone therapy as appropriate to the patient's gender goals (for two referrals by a mental health professional).

Exclusion Criteria:

1. <18 years old
2. Unable to consent for themselves
3. History of coagulopathy or bleeding disorders
4. History of thromboembolic events including deep vein thrombosis or pulmonary embolism.
5. Patients who are chronically anticoagulated, are on antiplatelet medications or have ever had an adverse reaction to IV TXA.
6. Prior history of chest surgery.
7. Known hypersensitivity or allergy to TXA
8. Patients with severe renal impairment .

Only researchers designated on the IRB study application will be allowed to access patient data.