Application of a Microsuction Background Device for Microanastomosis in a Rat Femoral Vessel Model

Performing microvascular anastomoses can be challenging when oedematous fluids and blood continuously flood/compromise the field of view. Intermittent irrigation and suctioning disturb workflow, requires an assistant, and can increase risk of arterial thrombosis, from vessels being drawn into suction drains. We developed and patented a novel, 3D-printed background device with microfluidic capabilities, to provide autonomous, continuous irrigation and suction to optimise operator autonomy and efficiency. We then tested this in a rat femoral vessel model. Twelve end-to-end anastomoses were performed by 2 senior microsurgeons (6 conventional, 6 suction-assisted background, SAB) in a rat femoral artery model. The primary outcome was time taken to complete the anastomosis. Secondary outcomes included: the validated Structured assessment of microsurgery skills (SAMS) score; and the total number of ‘wiping’ events to obtain field clarity. Each procedure was recorded, and videos were independently rated by two blinded experts using the SAMS score. Time taken to complete the anastomosis was greater in the conventional group compared to SAB group (741.7 secs + 203.1 vs 584 secs + 155.9, p=0.007). The median SAMS score was lower in the conventional group compared with SAB group (32.3 + 1.4 versus 38.3 + 1.5, p=0.001). The median number of ‘wiping’ events was significantly greater in the conventional group compared with the SAB group (13 + 2.2 versus 1.7 + 1.2, p<0.001). We showed that a novel, microfluidic background device allows continuous, irrigation and suctioning, without need for assistant, and optimises the efficiency of the microvascular anastomosis.