Novel Experimental Technique to Create Size-Controlled Retroperitoneal Bleeding in the Infrarenal Aorta of Anesthetized Pigs

Objective Rupture of abdominal aortic aneurysm (rAAA) with a contained retroperitoneal hematoma is potentially fatal. Physiological studies are difficult to perform in patients suffering from life-threatening conditions such as rAAA. A translational model of the condition is therefore needed. The aim was to develop and validate an endovascular animal model for retroperitoneal bleeding of the abdominal aorta with contained hematoma. Methods In anesthetized pigs, a puncture hole was made in the posterolateral portion of the infrarenal aorta by an Outback re-entry catheter device. The hole was gradually enlarged using angioplasty balloons to a specific diameter of either 4 mm ( n = 6), 6 mm ( n = 7), or 8 mm ( n = 6). Onset of bleeding was verified by angiography and macroscopically examined on completion of the experiments. Survival up to 180 min was the primary outcome. Hemodynamic and metabolic markers in arterial blood were secondary outcomes. Results Aortic injury with a contained retroperitoneal hematoma was achieved in all animals. Survival rate at 180 min after onset of bleeding was higher in the 4 mm group compared to the 6 mm ( P = 0.021) and 8 mm groups ( P = 0.002), but not when comparing the 6 mm and 8 mm groups. Systemic hypotension, arterial acidosis, and lactatemia were provoked in the 6 mm and 8 mm groups but not in the 4 mm group. Conclusions A porcine model for a controlled contained left posterolateral retroperitoneal bleeding was created using endovascular methods and validated. This model makes it possible to study the pathophysiology of a retroperitoneal hematoma.

Spontaneous retroperitoneal bleeding secondary to celiac artery compression syndrome

A 56-year-old woman was found to have retroperitoneal hemorrhage secondary to isolated posterior inferior pancreaticoduodenal artery (PIPDA) dissection. She had chronic abdominal pain and celiac artery stenosis, suggesting that PIPDA dissection was associated with celiac artery compression syndrome (CACS). Clinicians may consider CACS as the cause of visceral dissection.

COVID-19-Associated Retroperitoneal Hemorrhage: Same Complication, Two Different Types of Treatment

One of the reasons for the high mortality in COVID-19 patients is the increased risk of disseminated intravascular coagulation (DIC) and venous thromboembolism. For this reason, the use of anticoagulant treatments has become widespread. One of the rare complications of anticoagulant therapy is retroperitoneal hemorrhage. These hemorrhagies require immediate intervention. Retroperitoneal hemorrhage should be kept in mind among the many complications that develop in the patient who was followed up during the pandemic period. For this purpose, we present 2 cases who developed spontaneous retroperitoneal bleeding while clinically recovering under COVID-19 treatment.