Treatment of Head and Neck Paragangliomas

Kenneth Hu, MD; Mark S. Persky, MD

Disclosures

Cancer Control. 2016;23(3):228-241. 

In This Article

Surgery

Prior to surgery, the health care professional should typically perform an angiographic evaluation. To evaluate for use of anesthesia, the presence of catecholamine-secreting tumors should be considered because they require an alpha- and beta-adrenergic blockade. Continuous arterial pressure monitoring is ideal, and preparing for possible blood transfusions should be expected.

Based on our experience with paragangliomas, any proposed treatment must be individualized to each patient. Issues to be considered include patient age, medical comorbidities, location and size of the tumor, possible presence of synchronous tumors, and a history of progressive neurological dysfunction.

Angiographic Evaluation

An important preoperative adjunct for the surgical approach to paragangliomas is superselective angiography because it can be used for arterial mapping to identify tumor blood supply, tumor flow dynamics, and — perhaps the most important — the displacement of major vessels. Angiography is particularly useful for patients whose tumors are large and are supplied by the external and internal carotid arteries and anastomoses are present between the internal and external carotid systems.[22] The health care professional should evaluate the internal carotid artery for areas of irregularity or constriction as well as the structural integrity of the vessels, because either may indicate that removal could be necessary. Equally important is the venous phase of angiography because it can help the health care professional identify draining vessels, and evaluate the amount of invasion and occlusion of the lumen of the jugular bulb, jugular vein, and sigmoid sinus — which are characteristic findings of jugulotympanic paragangliomas.

If the surgeon anticipates that disruption or removal of the internal carotid artery might be necessary during surgery, then he or she must evaluate for adequate contralateral cerebral circulation; several methods can be used for this purpose. Although it is not available in all settings, xenon CT in conjunction with ipsilateral balloon occlusion can be useful to measure cerebral flow.[23,24] While monitoring the clinical neurological status of the patient, temporary balloon occlusion of the internal carotid artery if a patent circle of Willis is present may be easier to perform. In addition, this method is reliable: Approximately 93% of patients can tolerate removal of their ipsilateral internal carotid artery based on findings from the angiographic evaluation.[9] It is worth noting that conditions in the operating room and the angiographic suite may differ in terms of the cerebral delivery of oxygen.[9] A patient's tolerance for the temporary occlusion of the internal carotid does not preclude the possibility that a delayed cerebrovascular ischemic event may occur following surgery. Particularly among patients with jugulotympanic paragangliomas, venous outflow of the contralateral and ipsilateral transverse sinus and jugular systems should be evaluated. Because anatomical variations exist, an absent or contralateral hypoplastic jugular system may be a contraindication for surgery because of an increased risk of venous stroke after surgery.[25–27]

Embolization

Embolization is important adjunct therapy, and this is especially true for surgery to treat large paragangliomas. Experienced interventional radiology teams are necessary to avoid surgical complications. Embolization carries the risk of the potential migration of embolization particles into the cerebral circulation, thus resulting in stroke, and it is known to occur in the presence of anastomoses between the internal and external carotid systems or flow reversal from the arterial blood supply of the tumor. Advantages to embolization include tumor shrinkage, decreased blood flow, and additional surgical benefits. A decrease in the rate of intraoperative bleeding after embolization results in fewer transfusions, making for more effective tumor dissection with more well-defined tissue planes and more effective identification and preservation of normal anatomical structures, including the cranial nerves. Larger paragangliomas usually demonstrate multiple arterial feeding vessels that should be individually addressed through superselective angiography. With progressive embolization of these vessels, additional compartments of the tumor are devascularized until a tumor "blush" is absent. Surgery should be performed within 48 hours of embolization to avoid collateral or intracranial arterial supply, and steroids should be administered to reduce the inflammatory response following embolization.[28,29]

Observation

Judicious observation may be appropriate for select patients prior to performing surgery or providing radiotherapy. Small- or moderate-sized, unilateral carotid body tumors can be easily and safely resected; however, enlarging tumors or progressive neurological dysfunction warrants intervention.

Carotid Body Tumors

The surgeon can make an oblique vertical incision along the anterior border of the sternocleidomastoid muscle to visualize large-sized tumors; by contrast, a transverse neck incision across the sternocleidomastoid muscle should be made to approach small-sized carotid body tumors. Dissection distal and proximal to the tumor helps the surgeon identify the common, internal, and external carotid arteries, and vessel loop control must be applied to anticipate possible injury to the carotid. Precautions related to carotid bypass must be available.

The surgeon should expose the most superior and inferior extent of the internal carotid artery; typically, the vessel is posterolaterally displaced. Because hemostasis is generally feasible with paragangliomas, tumor embolization prior to surgery is unwarranted.[1–3] The surgeon should use caution when dissecting the tumor in the subadventitial plane. Although it should be avoided in most cases, external carotid artery sacrifice may be required if the artery is encased and infiltrated by the tumor. The last surgical step when dissecting the tumor (at the bifurcation of the common carotid artery) occurs when the artery is at its most vulnerable point for damage.[1–3] The surrounding cranial nerves in carotid body tumors may have marked hyperemia of the vasa nervosum of their nerve sheath. In larger tumors, these nerves may be involved and their dissection may cause dysfunction of the hypoglossal, vagus, and glossopharyngeal nerves. Ligation of the external carotid artery has been previously reported as a way to control blood flow to the tumor, but this maneuver should be avoided because it does not affect blood flow to the tumor and collateral circulation may be profuse.[1–3]

Jugulotympanic Paragangliomas

The surgeon can perform tympanotomy to approach small-sized tympanic paragangliomas through the external auditory canal. Embolization of these small tumors is not required. Larger-sized tympanic paragangliomas that are confined to the mastoid, middle ear, or both places without breaching the bone across the jugular bulb or the jugulo carotid spine can be exposed through a combined postauricular/endaural approach.

The surgeon is required to combine the temporal and cervical approaches when the jugular bulb is involved. Because intraluminal vascular invasion will be present, the surgeon is required to pack or ligate the internal jugular ligation located inferior and the sigmoid sinus located superior to tumor involvement. The surgeon must also proximally and distally trace and identify cranial nerves IX, X, and XI. More advanced tumors with the potential to involve various branches of the petrous carotid artery that may also extend into the intracranial area might require a postauricular infratemporal fossa approach.

The modes of spread for jugular paragangliomas are shown in Fig 3.[3]

Figure 3.

Modes of spread for jugular paragangliomas.
From Persky MS, Hu KS. Paragangliomas of the head and neck. In: Harrison LB, Sessions RB, Hong WK, eds. Head and Neck Cancer: A Multidisciplinary Approach. 3rd ed. Lippincott Williams and Wilkins, Philadelphia, PA; 2009. Reprinted with permission by Wolters Kluwer.

Vagal Paragangliomas

Located below the jugular foramen (~ 2 cm), vagal paragangliomas typically begin in the inferior (nodose) vagal ganglion. They have also been known to originate in the middle and superior ganglia, situated within the jugular foramen; this location results in early skull-base invasion and, in some cases, extends to the intracranial space. Growth of tumors bidirectionally along the vagus nerve will also inferiorly and superiorly involve the poststyloid parapharyngeal space and jugular foramen, respectively. In general, the internal carotid artery is medially and anteriorly displaced.[7] The surgical approach for jugulotympanic paragangliomas involving the skull base is similar to vagal paragangliomas.

The modes of spread for vagal paragangliomas are shown in Fig 4.[3]

Figure 4.

Modes of spread for vagal paragangliomas.
From Persky MS, Hu KS. Paragangliomas of the head and neck. In: Harrison LB, Sessions RB, Hong WK, eds. Head and Neck Cancer: A Multidisciplinary Approach. 3rd ed. Lippincott Williams and Wilkins, Philadelphia, PA; 2009. Reprinted with permission by Wolters Kluwer.

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