Background and Objective: In recent years, postmortem angiography has been considered as a minimally invasive approach in forensic medicine. This method helps to discover the causes of sudden cardiovascular deaths. However, washing out clots formed after death and not destroying clots during life (such as pulmonary embolism) are important technical challenges of this method. This experimental study was conducted with the aim of optimizing and standardizing the postmortem angiography protocol on 4 dogs.

Methods: This study examined establishing artificial blood circulation with a perfusion pump at 6 and 24 hours after death in 4 dogs. Different vascular access methods, including conventional peripheral cannulas, central cardiac cannulation, and large-caliber peripheral cannulas, and a postmortem clot dissolution protocol with 100 mg alteplase, were evaluated. By creating a pulmonary embolism model, the persistence of clots during life after the washing protocol was measured.

Findings: The results showed that conventional narrow cannulas failed due to resistance of cadaveric clots and caused pulmonary edema. In contrast, large-caliber femoral cannulas (14-16 French arterial and 18-21 French venous) with 100 mg alteplase injection and 30 minutes of pump circulation produced high-quality images at 6 and 24 hours after death. In addition, the embolic clot formed during life remained resistant to alteplase and was clearly recognizable on final angiography.

Conclusion: Postmortem angiography using large-caliber peripheral cannulas and flushing with alteplase is a completely practical and stable method (up to 24 hours after death). This method shows the vascular pathway for accurate forensic diagnosis without falsely clearing life-time clots.