Can Angiography Be Planned Based on Specific CT Signs of Ongoing Soft Tissue Bleeding in COVID-19 Patients Receiving Anticoagulants?

Background . Anticoagulant therapy is recommended as basic medical treatment for COVID-19 patients with risk factors. At the same time, it is accompanied by a large number of hemorrhagic complications. Massive bleeding into abdominal and chest walls soft tissues as well as retroperitoneal space significantly worsens the course of underlying disease. Objective : to assess the prognostic value of specific CT signs and their correlation with angiography data for the diagnosis of ongoing bleeding into soft tissues in COVID-19 patients. Material and methods. A retrospective study was conducted, in which multi-slice computed tomography (MSCT) and angiography data were assessed and compared in 60 COVID-19 patients with spontaneous bleeding into chest and abdominal wall soft tissues as well as retroperitoneal space. A retrospective analysis of MSCT was carried out to identify symptoms specific to coagulopathic bleeding into soft tissues: contrast agent extravasation, hematocrit effect, and signal flare phenomenon. Results. Contrast agent extravasation identified by MSCT was confirmed in 57 (95%) patients. More often (39 (68.4%) patients), extravasation was detected in MSCT arterial phase. In MSCT venous phase it was noted in 17 (29.8%) cases, in delayed phase – in 1 (1.8%) patient. With native MSCT, hematoma contained clots and fluid level (hematocrit effect) in 43 (71.7%) patients, in 17 (28.3%) patients it had a homogeneous structure. With intravenous contrast, in 39 (90.7%) cases with fluid level the signal flare phenomenon was established, which was more often detected in the arterial phase (33 (84.6%) cases). Extravasation was detected on angiography in 27 (45%) patients; they underwent therapeutic embolization. In another 15 patients preventive embolization was performed. When extravasation into hematoma without fluid level on MSCT (13 cases), extravasation on angiography was detected in 4 (30.8%) patients. In the presence of extravasation into hematoma with fluid level, but without signal flare phenomenon (4 patients) it was noted on angiography in 1 case. In the presence of all three signs (extravasation, hematocrit effect, and signal flare phenomenon – 39 patients), the incidence of extravasation on angiography was the highest – 56.4% (p = 0.028), and patients more often required therapeutic embolization. Conclusion. Detection of extravasation, fluid level and signal flare phenomenon on MSCT in the structure of spontaneous hematoma in COVID-19 patients corresponded to ongoing bleeding and more often required embolization than in isolated extravasation.