Arterial vasculature of cervical skin flaps

Old age and preoperative radiotherapy both decrease the blood supply to neck skin. It is therefore necessary to know how the skin flaps which are raised in neck surgery, receive their blood supply. By using silicone rubber injections we have studied the blood supply to the cervical skin in human cadavers before and after the elevation of flaps. There is a network of small vessels between the platysma and the skin originating from the external carotid artery superiorly and the subclavian artery inferiorly. There is a distinct watershed between the areas supplied by these two vessels; furthermore there is very little anastomosis across the mid-line. The richest arterial supply lies superiorly and the worst inferiorly and medially. In the intact neck, the vascular network is filled from underlying arteries, whereas in the elevated flap the network is filled from the base of the pedicle. On this evidence we suggest that: --the platysma should be included in the flap to conserve the vascular network --the horizontal limb of an incision should lie in the watershed --the upper flap should be larger than the lower flap.