Abstract
Functional carotid body tumours are rare, but linked to malignant hypertension, postoperative persistent hypotension, cranial nerve injury and stroke. The aim of this study is to analyze the treatment options for functional carotid body tumours. Six patients with functional carotid body tumours who underwent surgical procedures were studied retrospectively. They all had abnormal levels of preoperative catecholamine (norepinephrine, 721 ± 452.2 ng/l). One patient presented preoperative hypertension. Preoperative alpha- and beta-adrenergic blockade was carried out. Surgical methods included complete resection (6), saphenous vein interposition (3) and carotid shunt (1). With thorough supervision and treatment, the 6 patients underwent tumour resection. They all experienced intraoperative hypertension while the tumours were being resected. Postoperative problems included endurance hypotension (3/6, 50%), coughing when drinking (3/6, 50%) and deviation of the tongue on protrusion (3/6, 50%). The clinical highlights of functional carotid body tumour include preoperative abnormal catecholamine, peroperative fluctuations of blood pressure level, and regime issues. Operative resection could be the best option for functional carotid body tumours. Careful preoperative evaluation, measurement of serum catecholamine, treatment for alpha- and beta-adrenergic blockade, and gentle intraoperative manipulation are essential to avoid life-threatening complications.
Functional paragangliomas are neoplasms of the adrenal or extra-adrenal tissue which synthesize catecholamines. The common paragangliomas in the head and neck, carotid body tumours (CBTs), are mainly nonfunctional. However, some CBTs are functional and convey catecholamine or trigger catecholamine-induced signs and symptoms, for instance heart palpitations, dizziness, headache and hypertension. The mortality and morbidity associated with CBTs have improved greatly as a consequence of the continuing development of contemporary image resolution and vascular operative techniques including intraoperative shunt. Additional complications of functional CBTs include preoperative malignant hypertension, postoperative persistence of hypotension, cranial nerve injury and stroke. The resection of functional CBTs necessitates careful preoperative assessment and medical attention, delicate intraoperative adjustment and cautious perioperative observation. This study appraises the treatment options for functional CBTs.
Patients and methods
The records of six patients with functional CBTs (5 females and 1 male) who underwent surgical resection at the Division of Vascular Surgery in West China Hospital between January 2005 and April 2011 were reviewed retrospectively. All patients presented with abnormal catecholamine (norepinephrine 721 ± 452.2 ng/l; range 476–1637 ng/l; normal range 174–357 ng/l; epinephrine, normal). The mean age was 37.8 years (range 20–58 years). CBTs were established and diagnosed by colour duplex, computed tomography (CT), computed tomography angiography (CTA) and digital subtraction angiography (DSA). Four tumours were located on the right side and one on the left; no one had bilateral CBT. The mean size of the CBTs was 5.2 ± 1.4 cm. Five tumours were grouped in Shamblin’s class III, and one was class II. Comorbid conditions included hypertension (1, 16.7%) and unclear hypokalemia (1, 16.7%).
The hypertension and hypokalemia were remedied prior to surgical treatment. Preoperative alpha- and beta-adrenergic blocking agents were effective.
The surgical procedures took place under general anaesthesia. Once the adjoining nerve fibres had been delicately isolated from the carotid arterial blood vessels, the CBT was excised from the carotid arteries. If the tumour was difficult to separate from the carotid arties or the internal carotid artery was damaged by the tumour, saphenous vein interposition or carotid shunt could be performed. The shunt was a silicone balloon shunt (Edwards T3103A, 9F, 30 cm, Edwards Lifesciences, Irvine, CA, USA) with a check valve, used between the internal and common carotid arteries. The internal carotid artery was effortlessly uncovered across the shunt and the tumour was excised. To counteract intraoperative malignant hypertension, the tumour is gently resected and antihypertensive drugs including sodium nitroprusside can be employed. Postoperatively, significant hypotension may occur. Dopamine and adrenocortical hormone could be used.
All tumours were examined pathologically, including haematoxylin–eosin staining, chromogranin A, S-100 and synaptophysin. All patients were followed-up with catecholamine and potassium monitoring, as well as with duplex and/or CT.
All analyzes were performed using SPSS 19.0 statistical software. All continuous data were analyzed by descriptive statistics and expressed as mean ± SD.
Results
All of the operations performed on functional CBTs were successful. The intraoperative and postoperative data are shown in Table 1 . No patients underwent preoperative embolization. The surgical methods included carotid body tumour resection ( n = 6, 100%), vascular reconstruction with autologous saphenous vein grafts ( n = 2, 33.3%) and carotid shunt ( n = 1, 16.7%). Intraoperative hypertension, up to 220/75 mm Hg, occurred in all 6 patients when the tumours were resected. The peak norepinephrine level was 3620 ± 973.6 ng/l. Antihypertensive drugs were used to control blood pressure. The mean intraoperative blood loss was 1083 ± 1204 ml, the mean blood transfusion was 733 ± 734 ml, and the mean operative time was 226 ± 94 min. The mean postoperative time was 8.3 ± 2.9 days.
| Surgical approach | |
| CR | 6 (100%) |
| SVI | 2 (33.3%) |
| CS | 1 (16.7%) |
| Peak norepinephrine | 3620 ± 973.6 |
| Blood loss (ml) | 1083 ± 1204 |
| Blood transfusion (ml) | 733 ± 734 |
| Operative time (min) | 226 ± 94 |
| Postoperative hospitalized time (days) | 8.3 ± 2.9 |
| Complications a | |
| Persistent hypotension b | 3 (50%) |
| coughing when drinking | 3 (50%) |
| Deviation of the tongue on protrusion | 3 (50%) |
| Dysphagia, cerebral infarction and death | 0 |
a Preoperative hypertension, hypokalemia and postoperative severe hypotension were improved before discharge.
b Occurred for 6–7 days despite adequate blood transfusion and crystalloid infusion, used to maintain intravascular volumes, and dopamine.
Postoperative complications included persistent hypotension (3/6, 50%), coughing when drinking (3/6, 50%) and deviation of the tongue on protrusion (3/6, 50%). Persistent hypotension lasted for 6–7 days despite adequate blood transfusion and crystalloid infusion being used to maintain intravascular volumes; dopamine was also used. Preoperative hypertension, hypokalemia and postoperative severe hypotension were improved before discharge.
All tumours were confirmed as paragangliomas by histopathological analysis. Immunohistochemical results showed chromogranin A, S-100 (+) and synaptophysin (+), but no proof of function was found through histopathological analysis.
During the follow-up period (12–60 months), no recurrence occurred as assessed by CT and/or duplex. No catecholamine-induced symptoms or hypokalemia were found.
Results
All of the operations performed on functional CBTs were successful. The intraoperative and postoperative data are shown in Table 1 . No patients underwent preoperative embolization. The surgical methods included carotid body tumour resection ( n = 6, 100%), vascular reconstruction with autologous saphenous vein grafts ( n = 2, 33.3%) and carotid shunt ( n = 1, 16.7%). Intraoperative hypertension, up to 220/75 mm Hg, occurred in all 6 patients when the tumours were resected. The peak norepinephrine level was 3620 ± 973.6 ng/l. Antihypertensive drugs were used to control blood pressure. The mean intraoperative blood loss was 1083 ± 1204 ml, the mean blood transfusion was 733 ± 734 ml, and the mean operative time was 226 ± 94 min. The mean postoperative time was 8.3 ± 2.9 days.
| Surgical approach | |
| CR | 6 (100%) |
| SVI | 2 (33.3%) |
| CS | 1 (16.7%) |
| Peak norepinephrine | 3620 ± 973.6 |
| Blood loss (ml) | 1083 ± 1204 |
| Blood transfusion (ml) | 733 ± 734 |
| Operative time (min) | 226 ± 94 |
| Postoperative hospitalized time (days) | 8.3 ± 2.9 |
| Complications a | |
| Persistent hypotension b | 3 (50%) |
| coughing when drinking | 3 (50%) |
| Deviation of the tongue on protrusion | 3 (50%) |
| Dysphagia, cerebral infarction and death | 0 |
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