Improving the visualisation of perforator arteries for anterolateral thigh flaps harvest in CT angiography via sublingual glyceryl trinitrate

Abstract

To investigate the improvement of image quality and visualisation of the anterolateral thigh (ALT) flap perforators on computed tomography angiography (CTA) after administration of sublingual glyceryl trinitrate (GTN). Sixty patients with oral lesions received thigh CTA examinations were divided randomly into two groups after administration of sublingual GTN (GTN group) or without administration of sublingual GTN (non-GTN group). Two radiologists calculated the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and assessed the image quality of each vessel. Besides, the grade of thigh artery, the lumen diameter of deep femoral artery, lateral circumflex femoral artery (LCFA), the descending branch of LCFA and its proximal and distal perforators, and the number and type of visible perforators were evaluated quantitatively. The SNR and CNR were not significantly different between the two groups (p>0.05). The image quality of CTA in the GTN group was significantly better than that in the non-GTN group (p<0.01). The lumen diameters of the deep femoral artery, LCFA, the descending branch of LCFA and its perforators were significantly larger in the GTN group than those in the non-GTN group (p<0.01). Compared with the non-GTN group, the number of visible perforators and the number of visible septocutaneous perforators were significantly more in the GTN group, and the qualitative grade of visible perforators was significantly higher (p<0.001). The administration of sublingual GTN in preoperative thigh CTA can improve the image quality and visualisation of perforator vessels, thus could help surgeons to select the optimum ALT flaps.