High Altitude Surgery: Carotid Body Tumors

a different kind of case here at Cirugia de Torax

A Carotid paraganglion / carotid body tumor in Bogotá, Colombia

K. Eckland, ACNP-BC, MSN, RN  & Ricardo Buitrago, MD

Case History:  62-year-old Hispanic female who presented with complaints of a right neck mass X 3 years, accompanied by occasional dysphagia, itching and soreness of right neck.  Patient denied history of weight loss, anorexia, aspiration or recent pneumonias.  No history of previous stroke.

Past medical / surgical history:  TAH, 25 years prior, Hypertension, previous DVT of the RLE. Home medications: ASA 100mg po Q day.

On examination, the patient had a palpable, reducible mass over the right carotid, with no bruits on auscultation.

Diagnostics:  carotid duplex showing a right-sided carotid body tumor arising at the bifurcation of the common carotid.  No evidence of hemodynamically significant atherosclerotic plagues, or elevated velocities.  Mass measured at 7cm at widest point.

Labs:  All labs within normal limits including a Hgb 16/ Hct 48


After administration of general anesthesia, and endotracheal intubation, the patient was positioned, prepped and draped in sterile fashion.  A 4cm vertical skin incision was made on the right side of the neck.  After blunt dissection and retraction of sternoclastomastoid muscle, the common carotid artery was identified and retracted  with a vessel loop.  Identifying the bifurcation and loosely clamped external and internal carotids.  Care was taken to identify and prevent injury to the hypoglossal nerve and fascial branches.

carotid body tumor, in situ

Extensive ligation of  tributary vessels was undertaken while performing blunt dissection to the avascular plane.  Once the tumor was separated from the carotid bifurcation, it was removed and sent for final pathology.

At the conclusion of the case, a small jp drain was placed.  The patient was awakened in the operating room and extubated.  Patient demonstrated no new neurological deficits.

less than 5% of tumors are malignant


JP drain was discontinued on the morning of POD#2 and the patient was subsequently discharged.  Patient reported no dysphagia, hoarseness or paresthesia.


The carotid body serves as an important function of the detection and moderation of hypoxia.  This has been shown in several studies of post-operative carotid endartectomy patients who are unable to adjust/ acclimatize to increasing altitude as well as the increased incidence of carotid body tumors (CBT) at altitudes of 2000 meters of greater (Ojeda Parades).

Carotid body tumors occur most frequently at altitudes greater than 2,500 meters but significant differences have been noted in the prevalence, size and other characteristics of carotid body tumors occurring at lower altitudes.  The vast majority (95%) of these tumors are benign but in a minority of these cases, these tumors may represent metastatic disease.

Despite the location of these tumors, (at the bifurcation of the common carotid into the external and internal carotid), the chances for successful excision and resection is high with a mortality of less than 1%.  The most common complication of this procedure is damage to the adjacent nerve, causing hoarseness.


Boedecker, C. C. (2011). Paragangliomas and paraganglioma syndromes.  Head and Neck Surgery, 2011 (10).  A nice review article of paragnaglions including paragrangliomas of the head and neck.

Cerecer – Gil, N. Y., Figuera, L. E., Llamas, F. J., et. al. (2010). Mutation of SDHB as a cause of hypoxia related high altitude paraganglion.   Clin Cancer Res 2010; 16: 4148-4154. [free full-text pdf.]

Conde, S. V., Ribeiro, M. J., Obeso, A., Rigual, R., Monteiro, E. C., Gonzalez, C. (2012, recently published research).  Chronic caffeine intake in adult rat inhibits carotid body sensitization produced by chronic hypoxia but maintains intact chemoreflex output. Molecular Pharmacology Fast Forward.  46 page report on animal study.  [full-text available.]

Moore, J. P., Claydon, V. E., Norcliff, L. J., Rivera-Ch, M. C., Leon-Velarde, F., et. al. (2006).  Carotid baroreflex regulation of vascular resistance in high-altitude andean natives with and without chronic mountain sickness.  Experimental Physiology 91(5); 907-913.  [free full-text pdf.]

Ojeda, L. P., Durango, E., Rodriquez, C., & Vivar, N. (1988).  Carotid body tumors at high altitude: Quito, Ecuador, 1987.  World J. Surg. 12: 856- 860.

Park, S. J., Kim, Y. S., Cho, H. R. & Kwon, T. W. (2011).  Huge carotid body ganglion.  J Korean Surg Soc 2011; 81: 291- 294.  Case report. [free full text pdf available.]

Rodriguez – Cuervasm S., Lopez – Garcia, J. & Labastida – Alemandro, S. (1998).  Carotid body tumors in inhabitants of altitudes higher than 2000 meters above sea level.  Head & Neck, Aug 1998: 374-377.  [free full-text pdf available.]

Authors conducted a study of 120 CBT in Mexico City, D.F looking at the incidence and characteristics of all CBTs over a thirty year period (1965 – 1995) in comparison to previously published reports of CBT at lower altitude.  Findings similar to previous and existing literature  with a predominantly female population (89% of cases).  Mean age 49.  Mean size 5.4 cm.   They reported a 20% incidence of cranial nerve injury after resection.

Ruben, R. J. (2007).  The history of the glomus tumors nonchromaffin chemodectoma: a glimpse of biomedical Camelot. Acta Oto-Laryngeologica 2007; 127: 411-416.  If you can get past his fanciful writing style which resembles an ardent love letter, the article gives a nice history of paraganglion tumors (including carotid body tumors).

Talking about carotid body tumors at XXIX Congreso Latinamericano de Cirugia Vascular y Angiologia

talking about the incidence of carotid body tumors at altitude with the world’s experts

This is not one of our usual topics here but since carotid body tumors  (CBT /carotid paraganglion) are often associated with increased altitude; we are pleased to bring more information about the condition from several of Latin America’s experts from Quito, Ecuador, Mexico City (D.F.), Bogotá, Colombia and La Paz, Bolivia.  (Also given the level of expertise in this room, on this specialized condition – it would be almost criminal not to report this information.)

We have requested copies of the powerpoint presentations to include here, so please check back soon.

re-section of a carotid body tumor

Dr. Oscar Ojeda Paredes, MD –  email: oscarle19@hotmail.com

discussed the incidence, presentation, diagnosis and treatment in Quito.  He also discussed the different characteristics in carotid body tumors occurring at altitude versus sea level.  While carotid body tumors have a genetic component related to abnormal mutations of Chromosome 11, tumors according at sea level  occur more frequently in familial patterns and reach larger sizes.  The majority of patients seen at altitude are less than 3 cm, and asymptomatic in nature with the exception of a palpable mass.  (This mimics the case presented here at CdeT.)

Several of the cases were in young females (less than 40 years).  Dr. Ojeda and Dr. Guerrero explained that this believed to be related to the increased incidence of hypoxia during pregnancy (due to hemodilution and vascular expansion) in women with the chromosomal mutation.

Powerpoint presentationTumores del Cuerpo Carotídeo Experiencia ecuatoriana (All content is the property of Dr. Ojeda).

During a separate presentation, Dr. Ojeda also addressed the rare complication of ‘Syndrome of Insufficient Baroreflex’

This sydrome occurs after the afferent fibers serving the carotid sinus are damaged during surgery (usually for the removal of carotid body tumors.)  The syndrome occurs most frequently in patients who have had bilateral surgery – and while uncommon is not limited to patients who undergo carotid body tumor resection – it has also been reported in the literature in carotid endarterectomy patients.

Dr. Valente Guerrero, MD (Mexico City, D.F). – email: valentecv@prodigy.net.mx  

Dr. Valente discussed the incidence of carotid body tumors in Mexico City.  Despite being at the lowest altitude of the respective cities – given the very large surrounding population – Dr. Valente reports a significant number of cases in his hospital, as well as the results of several studies conducted in Mexico City.  As mentioned in the literature, Dr. Guerrero (and the other presenting surgeons) report a very low incidence of malignacy.

Dr. Alberto Munoz, MD – National Cancer Institute (NCI) in Bogota, Colombia 

Dr. Munoz, vascular surgeon from Bogota, Colombia

Dr. Munoz reports that while the majority of these cases are referred to Head & Neck (ENT) surgeons – there is a fairly significant incidence of disease in Bogotá, with surgeons at the National Cancer Institute seeing 30 cases in 2008, and 48 cases in 2009.  (If you’ve read some of the other literature, you’ll realize this is a larger sample that frequently reported – for example one study reported only 120 cases over a 30 year period.)

Dr. Munoz reports that at his facility 8 – 10% of these tumors occur bilaterally, and are found of 10 – 12% of all carotid ultrasounds performed at NCI.   Dr. Munoz also reviewed the existing the existing body of literature, dating back to 1963 – which is surprisingly small (total of seven studies with a total 412 tumors – including a previous study with a 160 patients in Bogotá.)

Dr. Ivan Soto Vaca- Guzman, MD (La Paz, Bolivia) Email: isotovacaguzman@yahoo.com

Dr. Soto, Bolivian expert on carotid body tumors

Dr. Soto presented information regarding several of his cases, including a discussion of previous Bolivian publications on carotid paraglanglion, as well as more recent data from his institution.  This included a total of 467 patients with 134 patients (2005 – 2012).  In comparison with much of the previously presented data – in Dr. Soto’s experience and research, the majority of patients developed CBT on the left.  Similar to the other presenters the majority of patients were asymptomatic, and intra-operatively were found to have a Shamblin classification of  II.

His most recent work confirmed the previously demonstrated predilection for females – with a female to male ratio of 8:1.

He also discussed the use of a pre-operative grading system based on ultrasound results based on the Shambling classification system is limited as it is a surgical classification applied at the time of surgery.  He discussed a new classification system, called UPEC developed by Dr. Alvaro Balcazar, Dr. Lopez and Dr. Ivan Soto, Bolivian vascular surgeons.  The advantages of Balcazar’s  classification system is the prediction of complications – since tumors with extensive invasion into adjacent structures have a much higher risk of significant (and potentially life-threatening) bleeding.  Dr. Soto states that he rarely, if ever, needs to embolize the tumor prior to surgical removal.

The UPEC classification system – uses letters A – D to indicate the amount of tumor invasion.

Stage A:  without invasion

Stage B: partial invasion – partial invasion into the carotid only.

Stage C:  Extensive invasion – may extend laterally, or into cephalic or caudal areas.

Stage D:  Compromise of neighboring structures.

More about the study and the UPEC system:

Balcazar, A., Lopez, C. & Soto, I. (2011).  Tumor del cuerpo carotideo de altura. Revision de 35 anos. Conceptos actuales, manejo de 333 tumors y nuevo clasificacion.   Technicas endovasculares XIV (3): 3929 – 3939.  (page 40 of on-line document).

But what about Tibet?

One of the questions addressed at the conference was the absence of carotid body tumors in places such as Tibet (at significant elevation).   However, these differences are theorized to related to the chromosomal mutations that cause carotid hyperplasia in response to hypoxia.  So while hypoxia certainly exists at Mount Everest – people (particularly women) carrying this mutation may not.