Distal internal maxillary artery

The distal internal maxillary artery is the main arterial trunk supplying lesions in the nasomaxillary area (9,10,23]. Vascular supply is via the sphenopalatine artery of the internal maxillary artery, the alar and septal branches of the facial artery. 

Fig. 20.7. Massive EPX with hemodynamic instability following maxillofacial trauma. A large false aneurysm due to a vascular laceration of the distal internal maxillary artery (asterisk) is detected. After microcatheterization of the pathological arterial segment, it is embolized with proximal glue deposition, with rapid hemodynamic stabilization and control of the EPX...

The arteries supplying juvenile angiofibromas arise from branches of the external carotid artery (EGA). The tumor blush is intense and persistent. There is no arteriovenous shunting within the lesion. The contralateral EGA should be explored in all cases that reach the midline. The distal internal maxillary artery is the first vessel to investigate. Large tumors are also supplied by other branches... 

Autoregulation mechanisms have been described to be more effective in the internal maxillary artery and the pharyngo-occipital system, whereas the facial artery has not shown to respond as effectively. Vasoconstriction as a response for hypertension or mechanical trauma is observed in large or medium sized arteries whereas small distal arteries seem to react with true regulatory mechanisms. 

Ligature of the internal maxillary artery should be avoided. The unilateral and proximal aspect of the procedure will allow the development of ipsi-and contra-lateral anastomoses that will distally reconstruct the vessel, and will continue to favor rebleeding but without allowing subsequent selective catheterizations. 

---