Improved Survival in Vascular Pythiosis with Surgery and Azithromycin, Doxycycline, and Itraconazole Therapy: A Phase II Multicenter, Open-Label, Single-Arm Trial. Vascular pythiosis, caused by Pythium insidiosum, is a life-threatening disease with high mortality rate in patients with residual disease post-surgery. This study evaluated the effectiveness of a combination therapy of surgery , azithromycin, doxycycline, and itraconazole. In this open-label, Phase II multicenter trial, 51 patients were enrolled. Patients were categorized based on residual disease post-surgery (unresectable lesions, incomplete resection, or persistent symptoms). Patients with residual disease received azithromycin (500 mg daily), doxycycline (100 mg twice daily), and itraconazole (200 mg thrice daily) until beta-d