Interventional neuroradiology of the head and neck.

Vascular interventions are important and helpful for treatment of various pathologies of the head and neck. Interventional neuroradiology of the head and neck includes image-guided biopsies, vessel occlusion, and local chemotherapy. Knowledge of anatomy, functional relationships between intra- and extracranial vessels, and pathology are the basis for therapeutic success. The interventional neuroradiologist is responsible for appropriate selection of patients based on clinical information, indications, and risk assessment. Neuroradiologic imaging, especially CT and MR imaging, and appropriate analysis of angiographic findings help ensure indication for treatment and plan an intervention. Technical equipment, including an angiographic unit, catheters, needles, embolizing materials, and so forth, are important. Knowledge of hemodynamics is relevant to avoid complications and to find the optimal technique for solving the clinical problem. Indications for image-guided biopsies are preverterbal fluid-collections, spinal and paraspinal inflammations and abscesses, deep cervical malignancies, vertebral body, and skull base tumors. Special care should be taken to preserve critical structures in this region, including spinal nerve roots, cervical plexus, main peripheral nerves, and vessels. Indications for vessel occlusion are emergency situations to stop bleeding in vascular lesions (traumatic, malformation, or tumors) by reduction of pressure, preoperative reduction of blood flow to minimize the surgical risk, palliative occlusion of feeding vessels to produce tumor necrosis, or potential curative (or presurgical) occlusion of vascular malformations. Pressure reduction to support normal coagulation, such as epistaxis, in hereditary hemorrhagic telangiectasia can be achieved by proximal vessel occlusion with large particles or platinum coils. Prevention of intraoperative bleeding requires occlusion of the microvascular bed with small particles. Examples of these interventions are: a hemangioma of the hard palate, a juvenile angiofibroma, a hemangiopericytoma, a malignant meningioma, a malignant fibrous histiocytoma, and a glomus tumor. Effective treatment of vascular malformations, such as AV fistulas or angiomas, needs exact occlusion of the fistula or the angiomatous nidus, which is demonstrated in the case of an AV angioma of the base of the tongue. Chemotherapy with local intra-arterial cisplatin combined with intravenous administration of sodium thiosulfate as antidote is indicated as an adjuvant modality in a multimodal regimen of oropharyngeal squamous cell carcinoma or as palliative treatment of recurrent and otherwise untreatable malignant tumors of the head and neck. Examples are a carcinoma of the alveolar ridge, a squamous cell carcinoma of the floor of the mouth, and a nasopharyngeal lymphoepithelioma. Palliative treatment of a bleeding oropharyngeal cancer is another example of interventional treatment. Selective treatment, either occluding or pharmacologic, may be preoperative, palliative, or curative. The objective is reduction of surgical risk, improvement of quality of life, or curative therapy of a lesion. Thus, the interventional treatment should not be associated with morbidity or mortality. Major complications, such as cerebral stroke, blindness, or cranial nerve palsies, can result from application of inappropriate techniques or poor evaluation of angiographic findings and should be avoided in the majority of cases. Sometimes collateral lesions are unavoidable. These include inflammation, necrosis, and nerve damage. Based on neuroradiologic experience, most of those risks are predictable. The benefits, risks, and expected damages of neuroradiologic interventions must be balanced during the informed consent procedure with the patient. Avoiding complications, handling unavoidable problems, and dealing with complications is a skill founded on knowledge and experience. Continuing education is a firm basis to push the limits of interventions and expand benefits without increasing risk for the patient. Nevertheless, state-of-the-art external carotid intervention should, in skilled hands, have a permanent morbidity far below 1% and no mortality.