Purpose <p>We assessed the efficacy and safety of Purastat^®, a novel synthetic hemostat, for the treatment of exudative hemorrhaging in pulmonary artery (PA) stumps.</p> Methods <p>This single-arm prospective interventional study included eligible patients scheduled for anatomical pulmonary resection. Purastat^® was applied intraoperatively to patients with exudative hemorrhaging at the PA stump, where hemorrhaging persisted despite 30&#xa0;s of compression following dissection with an automatic suturing device. The primary endpoint was the rate of additional hemostatic treatment required, with a prespecified threshold of 25%. The secondary endpoints included the time to achieve hemostasis, rate of postoperative rebleeding, and adverse events.</p> Results <p>Sixty-four patients were enrolled, and 80 PAs from 56 patients were dissected using an automatic suture device. Exudative hemorrhaging occurred in 31 PA stumps (38.8%), and hemorrhaging persisted after 30&#xa0;s of compression in 23 cases (28.8%) in which Purastat^® was applied. The rate of additional hemostatic treatment required was 4.35% (95% confidence interval, 0%–19.0%; only 1 patient), meeting the prespecified threshold. The median time to achieve hemostasis was 30.0&#xa0;s. No serious adverse events or postoperative rebleeding was observed.</p> Conclusion <p>Hemostasis with Purastat^® for exudative hemorrhaging at the PA stumps was effective and had no serious safety concerns.</p>