Malignant Shamblin III Carotid Body Tumors Resected with Use of the Retrocarotid Dissection Technique in 2 Patients

Abstract

A carotid body tumor (CBT) is a chemodectoma that most often originates from a gangliocytoma at the carotid bifurcation.1 These neoplasms were classified into 3 types by Shamblin and colleagues.2 A Shamblin I CBT is small and localized, a Shamblin II surrounds vessels or partially encloses them, and a Shamblin III is large and fully encloses adjacent vessels. Surgical resection, the appropriate treatment for CBT, 3 has typically been challenging because of the tumor's high vascularity, involvement of the carotid vessels, and proximity to the cranial nerves.4 In 6% to 12.5% of cases, CBTs have malignant potential and tend to grow and invade locally, causing symptoms. 5We have reported our use of the retrocarotid dissection technique in the surgical treatment of benign CBTs, and the substantially shorter procedural times and hospital stays in comparison with using the standard caudocranial technique. 6 Here, we describe our first 2 cases of malignant Shamblin III CBTs resected by means of retrocarotid dissection. Case Reports Patient 1A 17-year-old girl with no relevant medical history was referred to our institution in June 2014 with an expanding, painless, right-sided submandibular mass. She reported no pain, hoarseness, dyspnea, or dysphasia. A computed tomographic angiogram (CTA) showed a 5 × 3.7 × 6-cm hypervascular mass in the right carotid bifurcation (Fig. 1). Laboratory findings included elevated levels of plasma metanephrine (137 nmol/L; normal, <0.5 nmol/L) and normetaneprine (252 nmol/L; normal, <0.9 nmol/L). After we discussed treatment options with the patient and her parents, she underwent surgical resection.During surgery, the patient's head was turned toward her left. We then made a cervical incision centered over the carotid bifurcation, parallel and anterior to the sternocleidomastoid muscle, with extension to the mastoid region ( Fig. 2A). We extended the incision through the platysma muscle and down to the carotid sheath, and then pulled the jugular vein laterally. Proximal control of the common carotid artery was obtained just above the omohyoid muscle. Upon exposing the tendon of the digastric muscle, we identified the hypoglossal nerve and encircled it with a vessel loop. We ligated the common facial vein and performed subadventitial dissection of the mass

Technique modification proposal for carotid body tumors resection: trans-bulb dissection technique (TBD)

“…Given the fact that paragangliomas are not very often surgically treated by vascular surgeons, at least in Mexico, there are many options to prevent internal carotid damage, with good variable results, including pre-operative protective stenting of the internal carotid artery 6,7 , embolic techniques previous resection (endovascular or percutaneous) 8,9 , and the best non-drug dependent post-procedure option: technique modifications and improvements, as mentioned before, like the RCD 4,10 and this time ours.…”

Assessment of health-related quality of life in patients prior to carotid body tumor resection

“…4,5 Mutations in mitochondrial complex II subunits A, B, C and D of the succinate dehydrogenase (SDH) gene have been related with these tumors. [6][7][8] The most common subunit mutation related to malignant CBTs is the SDHB. 6,7 Bilateral CBTs have been reported in the literature with an incidence of 7.3%, as well as in unilateral, bilateral CBT, most common chief complaint is an asymptomatic growing neck mass, though other uncommon symptoms could be present, such as hoarseness, hearing loss, dysphagia and cranial nerve paralysis in some cases.…”

“…6,7 Bilateral CBTs have been reported in the literature with an incidence of 7.3%, as well as in unilateral, bilateral CBT, most common chief complaint is an asymptomatic growing neck mass, though other uncommon symptoms could be present, such as hoarseness, hearing loss, dysphagia and cranial nerve paralysis in some cases. [8][9][10] CBTs have a slow growth pattern, with most being discovered incidentally when performing imaging studies for some other cause or as an asymptomatic cervical mass, nevertheless, when symptoms are present, it usually implies compression or infiltration of adjacent structures or a mass effect, 11 decreasing the healthrelated quality of life (HRQoL) in patients. HRQoL in patients with diagnosis of CBTs prior to surgery resection has not extensively been studied.…”

“…6,7 Bilateral CBTs have been reported in the literature with an incidence of 7.3%, as well as in unilateral, bilateral CBT, most common chief complaint is an asymptomatic growing neck mass, though other uncommon symptoms could be present, such as hoarseness, hearing loss, dysphagia and cranial nerve paralysis in some cases. 8–10…”

Carcinoma del glomus carotideo. Serie de casos

“…La técnica retro-carotidea también se ha descrito en el abordaje de estos tumores, especialmente en los malignos, implicando la resección de la arteria carótida externa con posterior reconstrucción, usualmente usando injertos de vena safena. Hinojosa describe en dos pacientes con GCM, un abordaje esta técnica, con lo que reportan mejor exposición del plano avascular, reducción del tiempo operatorio y menor pérdida de sangre23 .Jansen et al, en su metaanálisis respecto al manejo quirúrgico del glomus carotideo, analizan el riesgo de lesión del nervio craneal, la recurrencia y el abordaje quirúrgico según la clasificación Shamblin. Para los tumores grandes, con clasificación Shamblin III, describen alto riesgo de morbilidad en el abordaje quirúrgico, especialmente si se realiza manipulación de la arteria carótida interna o si se liga la arteria carótida externa.…”