Answer:
It appears that most surgeons use lidocaine with epinephrine, probably because the risk of flap loss in a bilobed flap is non-existent (given base-width ratio). To be more scientific, there is a study from 1978, in which the viability of flaps following injection with plain lidocaine vs. various concentrations of lidocaine with epinephrine were injected into flaps measuring 1-cm wide by 11-13 cm long was evaluated. It revealed that epinephrine concentrations of 1:200,000 and 1:400,000 were detrimental to delayed but not to undelayed flaps.