Blood flow assessment with magnetic resonance imaging after 1.9 microm diode laser-assisted microvascular anastomosis

Microvascular surgery associates intricate surgical techniques to join tiny blood vessels and help transfer large amount of tissues. Successful venous anastomosis remains the main challenge because inadequate blood flow correlates with a major risk of free flaps venous congestion and thrombosis. The aim of this study is to assess blood flow after laser-assisted microvascular anastomosis (LAMA) using a 1.9-microm diode laser.

LAMA was performed on a series of 10 external jugular veins of Wistar rats. Two stay sutures and a standard laser tissue welding technique (lambda: 1.9 microm; power: 110 mW) were used. Similarly, a series of 10 conventional venous anastomosis were performed (CSMA). In both groups, contralateral non-operated jugular veins were used as control. MRI was used to perform positioning, anatomical, angiographic blood flow sequences, 1 day post-procedure and at 1, 4 and 8 weeks.

Venous patency rate was 100% at the time of surgery. Mean clamping time was 7.9 minutes in the LAMA group compared to 11.4 minutes in the CSMA group. In the angiographic sequence, there were no aneurysms in both groups for all observation periods. At post-operative day 1, mean loss of blood flow at the level of anastomosis in the LAMA group was 7% compared with 22% in the CSMA group. At 1, 4 and 8 weeks, blood flow reduction was greater in the CSMA group: 34%, 38% and 41%, respectively, compared to 12%, 15% and 16% in the LAMA group. Moreover, three cases of thrombosis were observed in the venous anastomosis performed with the conventional technique at 1 (n = 2) and 3 months (n = 1).

The flow-MRI further demonstrates that 1.9 microm diode LAMA is a consistent, reliable and reproducible technique, capable of improving blood flow in veins when compared to conventional surgery.