Fistula between the carotid artery and larynx in a 67-year-old man.

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A 67-year-old man with a history of laryngeal squamous cell carcinoma that had been treated with primary radiotherapy 20 years earlier developed laryngeal radionecrosis, and he underwent tracheotomy for airway obstruction at an outside hospital. On postoperative day 3, he bled profusely from his nose, mouth, and tracheotomy site (estimated blood loss: >2 L). The bleeding stopped spontaneously, and the patient was transferred to our institution.

Computed tomography (CT) and CT angiography (CTA) detected a small pseudoaneurysm arising from the anterior aspect of the left carotid artery bifurcation (figure 1). After fluid resuscitation, the patient was taken to the operating room for a total laryngectomy. Intraoperatively, the left common carotid artery was found to be adherent to the left thyroid ala. Dissection of the vessel from the cartilage revealed the presence of a fistula tract from the carotid artery to the larynx. Proximal and distal control of the carotid artery was established, and a suture repair of the vessel was attempted. However, the tissue proved to be too friable, so ligation of the internal carotid artery was performed with adequate backflow from the distal aspect of the artery. The operation was then completed without further complication.

Histologic analysis of the larynx revealed necrosis of the left thyroid cartilage without evidence of carcinoma. The patient experienced no postoperative neurologic deficit, and postoperative CTA of the brain revealed adequate collateral circulation (figure 2).

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Carotid artery disruptions include a spectrum of disorders, from carotid exposure and asymptomatic pseudoaneurysms to acute vessel ruptures and ex-sanguination. (1) Risk factors for carotid artery rupture include radiation therapy, radical surgery, wound infection, pharyngocutaneous fistula, and recurrent carcinoma.1 Radiation therapy decreases blood flow to the carotid artery wall by obliterating the vasa vasorum, and it directly weakens vascular walls, as evidenced by necrosis and fragmentation of elastic fibers. (1,2) Neck dissection may further weaken large vessels by stripping vessels of the vasa vasorum or by removing overlying soft tissue.

Digital subtraction angiography (DSA) is the imaging modality of choice for the evaluation of carotid artery lesions. It provides high-resolution images that allow the physician to determine whether a lesion is amenable to intravascular therapy. However, DSA requires specialized equipment and personnel, and it is associated with a 1% risk of neurologic complications. (3)

CTA is evolving as an alternative to conventional angiography in a variety of clinical settings. CTA is widely available, and compared with conventional angiography, it is more rapid, less costly, and associated with a lower rate of complications. (4) Investigators have demonstrated that CTA has a high sensitivity and specificity for the detection of intracranial and skull base aneurysms. (5) CTA has not been proposed as a substitute for angiography in the setting of carotid disruption, although the images in our case demonstrated a pseudoaneurysm consistent with the area of fistula.

Management of a carotid rupture depends on its status at presentation. An exposed carotid artery is treated with local wound care, antibiotic therapy, and a covering of vascularized soft tissue. In patients with precarious wounds, elective carotid ligation may be considered after balloon test occlusion. (2) Patients with a fistula between the carotid artery and upper aerodigestive tract should be treated similarly to patients with impending and acute carotid rupture. The airway is secured, and aggressive cardiovascular resuscitation is performed. Manipulation of the neck beyond applying direct pressure should be avoided. Surgical exploration with ligation of the artery has historically been the therapy of choice for carotid rupture; exploration allows for debridement of necrotic tissue, resection of the diseased vessel, salivary diversion, and a wound covering with vascularized tissue.

Endovascular therapy is an alternative to surgical exploration, and it may improve outcomes in patients with acute carotid rupture. (6) However, placement of an intravascular stent within a potentially infected or necrotic vessel wound may predispose the patient to thrombosis, extrusion, or recurrent hemorrhage. Studies of outcomes following placement of an endovascular stent for carotid blowout have demonstrated a high risk of rebleeding. (7) Therefore, the authors of recently published treatment algorithms advocate endovascular therapy as a temporizing measure to stabilize the patient until the surgeon can perform a further workup to determine the risk of a cerebrovascular accident after occlusion or the need for an extra-anatomic bypass. (2) If occlusion or bypass is not possible, vascularized soft tissue may be placed in the wound to protect the vessel.

References

(1.) Citardi MJ, Chaloupka JC, Son YH, et al. Management of carotid artery rupture by monitored endovascular therapeutic occlusion (1988-1994). Laryngoscope 1995;105(10):1086-92.

(2.) Cohen J, Rad I. Contemporary management of carotid blowout. Curr Opin Otolaryngol Head Neck Surg 2004; 12 (2): 110-15.

(3.) Heiserman JE, Dean BL, Hodak JA, et al. Neurologic complications of cerebral angiography. AJNR Am J Neuroradiol 1994; 15 (8): 1401-7; discussion 1408-11.

(4.) Nijjar S, Patel B, McGinn G, West M. Computed tomographic angiography as the primary diagnostic study in spontaneous subarachnoid hemorrhage. J Neuroimaging 2007;17(4):295-9.

(5.) Sakamoto S, Kiura Y, Shibukawa M, et al. Subtracted 3D CT angiography for evaluation of internal carotid artery aneurysms: Comparison with conventional digital subtraction angiography. AJNR Am J Neuroradio12006;27(6): 1332-7.

(6.) Pyun HW, Lee DH, Yoo HM, et al. Placement of covered stents for carotid blowout in patients with head and neck cancer: Follow-up results after rescue treatments. AJNR Am J Neuroradiol 2007; 28(8):1594-8.

(7.) Sorial E, Valentino ], Given CA, et al. The emergency use of endografts in the carotid circulation to control hemorrhage in potentially contaminated fields. J Vasc Surg 2007;46(4):792-8.

Dary J. Costa, MD; Mark A. Varvares, MD; B. Kirke Bieneman, MD