A new method using surface landmarks to locate resuscitative endovascular balloon occlusion of the aorta based on a retrospective CTA study.

Abstract

Resuscitative endovascular balloon occlusion of the aorta (REBOA) can timely prevent the wounded from fatal hemorrhage. However, blind insertion of REBOA in field or emergency room may result in catheter malposition and serious complications. We aim to develop a new method based on surface landmarks to guide the accurate placement of REBOA in zone III of aorta without fluoroscopy. A retrospective study was conducted in a university hospital, including 57 subjects who underwent computed tomography angiography (CTA) from April to December in 2019. External distances and intravascular lengths were measured by three-dimensional reconstruction of CT images, including the distances from the insertion site of femoral artery to the xiphoid process (FA-Xi), the midpoint between the xiphoid process and the umbilicus (FA-mXU), the umbilicus (FA-Ui), the midpoint of the zone III of aorta (FA-mZIII), the lowest renal artery (FA-LRA), and aortic bifurcation (FA-AB). The distal and proximal ideal margin and predicted accuracy were calculated by curvature plane reconstruction. The predicted probability of balloon positioning in zone III by different methods was compared. The mean age of all patients was 60 years (SD = 9.4). The average length of zone III of aorta was 9.4 cm (SD = 1.0), and the length of FA-mZIII on the right and left sides were 24.4 cm (SD = 2.1), 23.8 cm (SD = 2.1), respectively. FA-Xi was longer than FA-LRA, and FA-Ui was shorter than FA-AB (paired two-tailed test, p < 0.001). Using three methods including the optimal quartering distances, the optimal distances below the xiphoid and above the umbilicus to predict the length of REBOA catheter positioning in zone III showed no statistically significant difference. The predicted accuracy of catheter positioning in zone III on the left and right sides guided by FA-mXU were 84.2% and 86%. The midpoint between the xiphoid process and the umbilicus may be a new surface landmark for people of normal weight to guide rapid positioning REBOA in zone III of aorta without fluoroscopy.