Discussion and Conclusion
The thyroid is a highly vascular structure and given its proximity to the airway any bleeding can be life-threatening. A haematoma post thyroid surgery is a rare, the risk is stated between 0.1-1.4%.7 Haematomas can occur immediately post-operatively or up to a week after, the majority occur within the first 6 hours post-operatively.8
TXA has a half-life of 2 hours, with a maximum concentration of approximately 1 hour after administration.6 The fibrinolytic effects last from 8 to 17 hours.6 The use of TXA peri-operatively is becoming more common for multiple specialties. Das et al used TXA for head and neck cancer surgery and showed that those receiving TXA were less to require a blood transfusion p < 0.0001.9 The study cannot be directly applied to thyroid surgery, however if offers further reassurance on the safety of TXA in head and neck surgery.
Our study suggests that that administering one dose of 1g TXA intravenously during thyroid surgery reduces the risk of post-operative haematoma. There were no adverse reactions in any of our patients from receiving TXA. All the bleeds in this study were not from a named vessel but rather a general slow bleed and we do not expect a TXA to change the outcome from bleeding from a named vessel.
There are a number of limitations to this study, it is a small study. A randomised study with larger sample sizes needs to be conducted to increase the validity of the result. Other confounding factors that should be evaluated include indication of surgery, anticoagulation, hypertension, age of the patients and the use of haemostatic agents such as Surgicel.
Although all the patients were operated on by an experienced surgeon, who had performed over 100 thyroid operations prior to this study, there were no bleeds in the final two years of the study, this could raise the possibility of a surgical learning curve having an impact on the bleed rate. Fan et al found that there was a relationship between the high versus low volume case load and post-operative haematoma, multiple factors are thought to cause this which include surgeon experience or hospital experience such as equipment used. 10 Our centre would be regarded as low volume and again that explain the higher bleed rate in the first cohort of patients who all didn’t have TXA.