This is a cumulative meta-analysis from Hong Kong reviewing 27 articles and a total of 7389 flaps. The authors, at the outset, acknowledge that the number of anastomoses is not the only factor of venous compromise and flap failure. Nonetheless they found that there was a significant difference in flap failure rate between the groups with one and two venous anastomoses. There was a significantly higher failure rate when one venous anastomosis was performed, similarly with venous compromise. There was no statistical difference in salvage success rate. They considered that the reduction in blood velocity increased in operative time and late detection of flap compromise may lead to a lower salvage success rate in those flaps with two venous anastomoses, this was not substantiated. The theoretically low flow rate is thought to predispose to venous thrombosis, although this was not found to be the case and this theoretical difference that had been raised was more applicable to tissue transfer to the lower extremities than to the head and neck. The role of coupling devises rather than suturing is yet to be evaluated.
