Arterial epistaxis.

If arterial ligation is contemplated and the site of bleeding has not been identified it is reasonable to ligate the external carotid or maxillary artery, on the basis that this vessel supplies the major part of the nose. If bleeding persists in spite of ligation, this does not mean that the wrong vessel has been tied off but that arterial anastomoses are allowing blood to seep from the ethmoidal to the sphenopalatine area of the nose. If the anterior ethmoidal artery is to be ligated it is worth remembering that in 14-3 per cent of cases the anterior ethmoidal artery is absent unilaterally and in 2-4 per cent of cases absent bilaterally (Shaheen, 1967). The presence of a foramen with a periosteal cuff going through it does not necessarily mean that there is an artery present (Fig. 23). Finally, the blood vessel changes which occur and which are responisble for the persistence of nose bleeds in the elderly are a collagenous change in the muscle coat of medium and small arteries and calcification (not atheroma) in the larger feeding vessels.