Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:This redistribution could favor venous congestion in some of the flaps, leading to the most common vascular complication, the diffuse venous congestion of the DIEP flap, neither caused by pedicle-related issues (such as venous thrombosis or kinking) nor by technical errors (for example, deficient suture or avulsion of the pedicle).[6,7] This phenomenon is observed in 2-10.
Category: