Effective bleeding control during resection of giant carotid body tumor

Carotid body tumor is a rare neoplasm located at the carotid bifurcation. Ligation and excision of the external carotid artery together with the tumor is preferred in patients with transmural tumor invasion. In those without transmural tumor invasion, temporary occlusion of the external carotid artery at the bifurcation allows trouble-free tumor excision and keeps the external carotid artery intact.     

Baroreflex and chemoreflex function after bilateral carotid body tumor resection

OBJECTIVE: To investigate whether bilateral carotid body tumor resection invariably and chronically affects arterial baroreflex or peripheral chemoreflex function. METHODS: We studied eight consecutive patients (two men and six women; ages 48.1 +/- 11.8 years), a median time of 3.4 years (range 1.3-20.6 years) after bilateral carotid body tumor resection, and 12 healthy control individuals (eight men and four women; ages 53.7 +/- 10.1 years). Baroreflex sensitivity (phenylephrine), blood pressure and its variability (24 h Spacelabs and 5 h Portapres recordings), responses to standard cardiovascular reflex tests and the ventilatory responses to normocapnic and hypercapnic hypoxia were assessed. RESULTS: Baroreflex sensitivity was lower in patients (6.4 +/- 7.2 ms/mmHg) than in controls (14.7 +/- 6.6 ms/mmHg; P +/- 0.011). Mean office blood pressure and heart rate were normal in patients (123.3 +/- 11.9/79.0 +/- 7.3 mmHg and 67.5 +/- 9.4 beats/min, respectively) and controls (117.8 +/- 10.6/74.0 +/- 6.8 mmHg and 61.1 +/- 9.2 beats/min, respectively). Blood pressure variability was increased during ambulatory measurements. Three patients exhibited orthostatic hypotension. The Valsalva ratio, an index of baroreflex-mediated cardiovagal innervation, was lower in patients (1.4 +/- 0.2) than in controls (1.8 +/- 0.5; P +/- 0.008). The normocapnic ventilatory response to hypoxia was absent in all patients, whereas a small residual response to hypoxia was observed under hypercapnic conditions in two patients. CONCLUSIONS: Bilateral carotid body tumor resection results in heterogeneous expression of arterial baroreflex dysfunction, whereas the normocapnic hypoxic drive is invariably abolished as a result of peripheral chemoreflex failure.     

Atypical colonic stromal tumor

We present the case of a female patient with atypical gastrointestinal stromal tumor. The young woman presented asymptomatic colonic perforation and showed atypical immunohistochemical findings. The various clinicopathologic characteristics and diagnostic tests, as well as treatment and distinct behavior of these tumors, are discussed.     

Baroreflex control of muscle sympathetic nerve activity after carotid body tumor resection

Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5 patients after bilateral carotid body tumor resection (1 man and 4 women, 51+/-11 years) and 6 healthy control subjects (2 men and 4 women, 50+/-7 years). Baroreflex sensitivity was calculated from changes in R-R interval and muscle sympathetic nerve activity in response to bolus injections of phenylephrine and nitroprusside. In addition, sympathetic responses to the Valsalva maneuver and cold pressor test were measured. The integrated neurogram of patients and control subjects contained a similar pattern of pulse synchronous burst of nerve activity. Baroreflex control of both heart rate and sympathetic nerve activity were attenuated in patients as compared with control subjects [heart rate baroreflex sensitivity: 3.68+/-0.93 versus 11.61+/-4.72 ms/mm Hg (phenylephrine, P=0.011) and 2.53+/-1.36 versus 5.82+/-1.94 ms/mm Hg (nitroprusside, P=0.05); sympathetic baroreflex sensitivity: 3.70+/-2.90 versus 7.53+/-4.12 activity/100 beats/mm Hg (phenylephrine, P=0.10) and 3.93+/-4.43 versus 15.27+/-10.03 activity/100 beats/mm Hg (nitroprusside, P=0.028)]. The Valsalva maneuver elicited normal reflex changes in muscle sympathetic nerve activity, whereas heart rate responses were blunted in the patients with bilateral carotid body tumor resection. Maximal sympathetic responses to the cold pressor test did not differ between the two groups. Denervation of carotid sinus baroreceptors as the result of bilateral carotid body tumor resection produces chronic impairment of baroreflex control of both heart rate and sympathetic nerve activity. During the Valsalva maneuver, loss of carotid baroreflex control of heart rate is less well compensated for by the extra carotid baroreceptors than the control of muscle sympathetic nerve activity.     

Surgical treatment of carotid body tumor: case report and literature review

Carotid body tumors (CBT) are rare chemical receptor tumors. We report nine cases of CBT who were diagnosed at our center during 2004 to 2008 with a literature review. Of these nine patients, eight underwent complete resection, one received palliative resection due to the malignant nature of the tumor, and the other one refused surgery. No perioperative mortality and stroke occurred. During a mean follow up of 2.2 years, no deaths related to CBT occurred. Surgical treatment for CBT is relatively safe. The surgeon should be careful to maintain the integrity of carotid artery, and prevent cerebral ischemia and cranial nerve injuries in order to improve outcome.     

恶性颈动脉体瘤合并闭经和泌乳一例

患者女 ,36岁 ,右下颌肿物 5年余伴低热 1年。于 1998年 11月 2日入院。 5年前发现右下颌蚕豆大小的无痛肿块 ,3年前出现停经、溢乳。根据血清催乳素 (ＰＲＬ)水平及头颅ＭＲＩ检查诊断泌乳—闭经症。口服溴隐亭治疗 ,月经恢复 ,催乳素降至正常水平 ,以后每日服溴隐亭 2 .5ｍｇ维持治疗。 2年前感右下颌肿物逐渐增大 ,行手术治疗 ,发现肿物呈椭圆形包绕颈内外动脉分叉部 ,因与颈动脉粘连紧密未能剥离。术后诊断 :颈动脉体瘤。经ＣＴ检查示右侧颈内外动脉分叉处 ,45ｍｍ× 48ｍｍ圆形低密度影 ,边界清 ,病灶将右侧颈内静脉向外推压 ,增强后病…     

The vasculature of the carotid body

A histological and electron microscopical study was carried out on the vasculature of the carotid bodies in seven subjects coming to necropsy. None of these had suffered from chronic hypoxaemia or systemic hypertension during life and none had hypertrophy of the right or left ventricle. The vasculature of the carotid bodies showed three distinct components. There was a proximal portion, comprising elastic interlobular arteries, which had a wall in which elastic tissue predominated and in which many nerve fibrils could be demonstrated. This is considered to be baroreceptor in nature. There was an intermediate portion comprising muscular intralobular arterioles which are believed to be capable of controlling the level of blood supply to the parenchyma of the carotid bodies. Finally there are glomic capillaries surrounded by elongated pericytes and sustentacular cells. One or other of these elongated cells is thought to be responsible for the carotid body hyperplasia which is associated with systemic hypertension and states of chronic hypoxaemia.     

Excitation of carotid body chemoreceptors by neuropeptide-Y

Neuropeptide-Y (NPY) is a peptide co-localised with noradrenaline in many sympathetic nerves. Recently, it has been found in postganglionic sympathetic nerves running to blood vessels in the carotid body. When NPY is administered to cats by infusion into the arterial blood close to the carotid bodies, breathing is stimulated. This effect is abolished when the carotid sinus nerves are cut. Similar intra-carotid infusions of NPY can be demonstrated to increase the frequency of firing of chemoreceptor afferent nerves. However, NPY introduced into the blood vessels of the carotid body immediately prior to halting its blood flow does not modify the development of chemoreceptor discharge in response to developing asphyxia. The findings are consistent with NPY causing excitation of chemoreceptors by causing local vasoconstriction and stagnant asphyxia.     

Transpharyngeal ultrasound detection of carotid body paraganglioma

We report a patient in whom a right carotid body paraganglioma was delineated using a transpharyngeal approach during a transesophageal echocardiographic (TEE) study. Color Doppler-guided pulsed-Doppler interrogation of the right internal carotid artery in the tumor region, revealed high maximum systolic and maximum diastolic velocities of 1.5 m/s and 1.0 m/s, respectively, suggestive of tumor compression.     

Obstructive sleep apnea following bilateral carotid body resection

A patient who had undergone bilateral carotid body resection five years earlier for palliation of chronic airflow obstruction was found to have severe obstructive sleep apnea. He presented with hypercapnic respiratory failure, which improved after tracheostomy. A physiologic mechanism is proposed to explain this association. Previously reported studies of anesthetized animals suggest that loss of peripheral chemoreceptor activity could selectively decrease neural output to the genioglossus, the main protrusor muscle of the tongue, predisposing the upper airway to inspiratory occlusion.