Reductive stress in mitochondria isolated from the carotid body of type 1 diabetic male Wistar rats.

The carotid body (CB) senses changes in arterial O2 partial pressure (pO2) and glucose levels; therefore, it is key for the detection of hypoxia and hypoglycemia. The CB has been suggested to detect pO2 through an increase in reactive oxygen species (ROS) in the mitochondria. However, the mechanism protecting the chemoreceptor cells and their mitochondria from ROS and hyperglycemia is poorly understood. Here we measured glutathione levels in CB mitochondria of control and in streptozotocin (STZ)-induced type 1 diabetic male Wistar rats. We found a dramatic reduction in total glutathione from 11.45 ± 1.30 µmol/mg protein in control rats to 1.45 ± 0.31 µmol/mg protein in diabetic rats. However, the ratio of reduced to oxidized glutathione, a measure of the redox index, was increased in diabetic rats compared to controls. We conclude that the mitochondria of CB chemoreceptor cells in type 1 diabetic male Wistar rats were likely under glutathione-reducing stress.

Ruptured carotid artery pseudoaneurysm following excision of a carotid body tumor: a rare complication managed successfully with surgery and literature review.

A 47-year-old male presented with a right-sided Shamblin type 2 carotid body tumor measuring 5*5 cm. After preoperative embolization, a sub adventitial resection of the tumor was done. He was discharged after postoperative day 5 and presented again to emergency 10 days later with a bleeding pseudoaneurysm at the surgical site causing dysphagia and dyspnea. He was taken for emergency exploration of the surgical wound and, intraoperatively, it was observed that the proximal ends of the internal carotid artery and external carotid artery close to the bifurcation were forming a pseudoaneurysm, 1 cm distal to the common carotid artery. The external carotid artery was ligated and a common carotid to internal carotid artery bypass was done with a reversed saphenous vein graft. He recovered well in the postoperative period and was discharged on day 7. Pseudoaneurysm formation following carotid body tumor resection is extremely rare and has only been reported thrice in the literature.

Um homem de 47 anos apresentou tumor carotídeo Shamblin tipo 2 no lado direito, medindo 5 x 5 cm. Após embolização pré-operatória, foi realizada ressecção subadventicial do tumor. O paciente teve alta no quinto dia pós-operatório e voltou à emergência 10 dias depois, com pseudoaneurisma hemorrágico no sítio operatório causando disfagia e dispneia. Foi levado para exploração emergencial da ferida cirúrgica, e, no intraoperatório, 1 cm distalmente à artéria carótida comum, as extremidades proximais da artéria carótida interna e da artéria carótida externa próximas à bifurcação formavam um pseudoaneurisma. A artéria carótida externa foi ligada, e foi realizada uma ponte de safena de carótida comum para a artéria carótida interna com a veia safena invertida. O paciente se recuperou bem no pós-operatório e recebeu alta no sétimo dia. A formação de pseudoaneurisma após ressecção de tumor do corpo carotídeo é extremamente rara, tendo sido relatada apenas três vezes na literatura.

Baroreflex and chemoreflex interaction in high-altitude exposure: possible role on exercise performance.

The hypoxic chemoreflex and the arterial baroreflex are implicated in the ventilatory response to exercise. It is well known that long-term exercise training increases parasympathetic and decreases sympathetic tone, both processes influenced by the arterial baroreflex and hypoxic chemoreflex function. Hypobaric hypoxia (i.e., high altitude [HA]) markedly reduces exercise capacity associated with autonomic reflexes. Indeed, a reduced exercise capacity has been found, paralleled by a baroreflex-related parasympathetic withdrawal and a pronounced chemoreflex potentiation. Additionally, it is well known that the baroreflex and chemoreflex interact, and during activation by hypoxia, the chemoreflex is predominant over the baroreflex. Thus, the baroreflex function impairment may likely facilitate the exercise deterioration through the reduction of parasympathetic tone following acute HA exposure, secondary to the chemoreflex activation. Therefore, the main goal of this review is to describe the main physiological mechanisms controlling baro- and chemoreflex function and their role in exercise capacity during HA exposure.

Paraganglioma of the Neck: A Rare Case With Spinal Metastasis.

Paragangliomas are rare neuroendocrine tumors that arise from the paraganglia, which are clusters of neuroendocrine cells associated with the autonomic nervous system. These tumors are commonly found in the adrenal medulla but can also occur in other locations outside the adrenal gland. Here, we present a case report of a slow-growing paraganglioma in the left neck with spinal metastasis in a 60-year-old man. This case highlights the importance of considering paraganglion tumors in the differential diagnosis of neck masses and the need for early diagnosis and management to prevent potential complications. Importantly, both the clinical picture and anatomical location of these tumors is important when determining treatment plans.

Retrocarotid dissection technique compared to the caudocranial approach for the surgical treatment of carotid body tumors: A 15-year experience.

INTRODUCTION: Carotid body tumors are rare neoplasms with malignant potential. We aim to follow up on our initial experience published in 2015 and compare the occurrence of complications and postoperative outcomes with the use of retrocarotid dissection (RCD) against the standard caudocranial (SCCD) technique. METHODS: This was an observational, case-control study in which we analyzed all of the carotid body tumor resections performed from 1986 to 2022. Parametric and nonparametric tests were used accordingly. Statistical analysis was performed on Stata 17. RESULTS: A total of 181 surgical procedures were included, mean age was 56 years (± 13.63), and 168 (93%) were performed in women. The mean medio-lateral diameter was larger in the RCD group (2.85 ± 1.57 cm vs 1.93 ±1.85 cm; p = 0.002) and presurgical embolization was more frequently performed in the SCCD group (27.5% vs 0.7%; p < 0.001). A total of 40 (22.09%) resections were performed using the SCCD technique. In contrast, in 141 (77.91%) procedures the RCD technique was used. The mean surgical time in the RCD group was lower (197.37 ± 70.56 min vs 232 ± 98.34 min; p = 0.01). No statistically significant difference was found between SCCD and RCD in terms of vascular lesions (n = 20 [11.04%], 15% vs 9%, respectively; p = 0.36), transient or permanent nerve injuries (25% vs 33%, respectively; p = 0.31), or mean intraoperative bleeding (SCCD: 689.95 ± 680.05 mL vs RCD: 619.64 ± 837.94 mL; p > 0.05). CONCLUSIONS: RCD appears to be a safe and equivalent alternative to the standard caudocranial approach in terms of intraoperative bleeding or vascular lesions, with a sustained, significant decrease in surgical time.

Tumor de cuerpo carotídeo en adolescente. Reporte de un caso / Carotid body tumor in an adolescent. A case report

Introducción. Los paragangliomas del cuerpo carotídeo son neoplasias infrecuentes y representan el 0,6 % de los tumores de cabeza y cuello. La edad de presentación promedio es la quinta década de vida. El objetivo de este artículo fue describir un caso de paraganglioma del cuerpo carotídeo en una adolescente. Caso clínico. Se presenta el caso de una paciente adolescente con paraganglioma de cuerpo carotídeo derecho, de 5x3x3 cm, Shamblin III. Se analizaron la historia clínica, los exámenes diagnósticos, la técnica quirúrgica utilizada y su evolución correspondiente. La información fue obtenida a partir de la ficha clínica, previa autorización por consentimiento de los padres de la paciente. Resultados. Se hizo resección quirúrgica completa y reparo vascular con injerto de vena safena invertida, con evolución favorable y permeabilidad completa del puente vascular, sin secuelas. Conclusión. Este caso podía corresponder a un tumor de etiología familiar, dada su edad temprana de presentación. Se hizo necesario complementar su estudio con imágenes y objetivar el compromiso vascular asociado para la planificación quirúrgica. En estos pacientes, la complejidad de su localización y el compromiso vascular del tumor requiere de un equipo multidisciplinario, con cirujanos de cabeza y cuello y cirujanos vasculares para un resultado exitoso.

Introduction. Carotid body paragangliomas are rare, representing 0.6% of head and neck tumors, with average age of presentation in the fifth decade of life. The objective of this article is to describe a clinical case of carotid body paraganglioma in an adolescent. Clinical case. Review and analysis of the clinical case, reviewing its clinical history, study tests, surgical technique used and its corresponding evolution. Information obtained from the clinical record prior authorization by consent of the patient's parents. Results. Adolescent patient with paraganglioma of the right carotid body, 5x3x3 cm, Shamblin III. With complete surgical resection and inverted saphenous vein graft, favorable evolution, with complete permeability of the vascular bridge, without sequelae. Conclusion. This case could correspond to a tumor of familiar etiology, given its early age of presentation. It is necessary to complement the study with images and to objectively determine the associated vascular involvement for surgical planning. In these patients, the complexity of their location and vascular involvement of the tumor requires a multidisciplinary team with head and neck and vascular surgeons for a successful outcome.

Hypoxia sensing in the body: An update on the peripheral and central mechanisms.

An adequate supply of O2 is essential for the maintenance of cellular activity. Systemic or local hypoxia can be experienced during decreased O2 availability or associated with diseases, or a combination of both. Exposure to hypoxia triggers adjustments in multiple physiological systems in the body to generate appropriate homeostatic responses. However, with significant reductions in the arterial partial pressure of O2, hypoxia can be life-threatening and cause maladaptive changes or cell damage and death. To mitigate the impact of limited O2 availability on cellular activity, O2 chemoreceptors rapidly detect and respond to reductions in the arterial partial pressure of O2, triggering orchestrated responses of increased ventilation and cardiac output, blood flow redistribution and metabolic adjustments. In mammals, the peripheral chemoreceptors of the carotid body are considered to be the main hypoxic sensors and the primary source of excitatory feedback driving respiratory, cardiovascular and autonomic responses. However, current evidence indicates that the CNS contains specialized brainstem and spinal cord regions that can also sense hypoxia and stimulate brain networks independently of the carotid body inputs. In this manuscript, we review the discoveries about the functioning of the O2 chemoreceptors and their contribution to the monitoring of O2 levels in the blood and brain parenchyma and mounting cardiorespiratory responses to maintain O2 homeostasis. We also discuss the implications of the chemoreflex-related mechanisms in paediatric and adult pathologies.

The effect of preoperative embolization rate on surgical outcomes for carotid paraganglioma resection

SUMMARY OBJECTIVE: Preoperative embolization of paragangliomas decreases tumor volume and reduces intraoperative blood loss. This study aimed to evaluate the effect of the rate of devascularization achieved by preoperative embolization of carotid body tumors on surgical outcomes. METHODS: Patients with carotid body tumors who underwent preoperative transarterial embolization between 2013 and 2024 were included in this retrospective study. The Shamblin classification of all patients was carried out using radiological imaging. Devascularization rates obtained after the embolization of carotid body tumors were determined from angiographic images. Patients were divided into two groups: near-complete embolization (devascularization rate >90%) and incomplete embolization (devascularization rate <90%). Hemoglobin loss was calculated with blood tests before and immediately after surgery. Tumor volume loss was calculated by preoperative radiological tumor volume and postoperative surgical specimen volume. Hemoglobin loss, tumor volume loss, and postoperative complication rates of the two groups were compared. RESULTS: A total of 31 patients with carotid body tumors who underwent surgery were included in the study. Near-complete embolization was achieved in 21 patients (67.74%), while incomplete embolization was achieved in 10 patients (32.25%). Shamblin classification was statistically similar (p>0.05) between the two groups. The vascular complication rate in the near-complete embolization group was significantly lower than in the incomplete embolization group (p=0.027). However, no significant difference was observed in neurological complication rates, hemoglobin loss, and tumor volume loss parameters between the two groups (p>0.05). CONCLUSION: The preoperative devascularization rate should be at least 90% to minimize the risk of vascular complications.

Ruptured carotid artery pseudoaneurysm following excision of a carotid body tumor: a rare complication managed successfully with surgery and literature review / Pseudoaneurisma de artéria carótida rompida após excisão de tumor do corpo carotídeo: uma complicação rara tratada com sucesso com cirurgia e revisão da literatura

Abstract A 47-year-old male presented with a right-sided Shamblin type 2 carotid body tumor measuring 5*5 cm. After preoperative embolization, a sub adventitial resection of the tumor was done. He was discharged after postoperative day 5 and presented again to emergency 10 days later with a bleeding pseudoaneurysm at the surgical site causing dysphagia and dyspnea. He was taken for emergency exploration of the surgical wound and, intraoperatively, it was observed that the proximal ends of the internal carotid artery and external carotid artery close to the bifurcation were forming a pseudoaneurysm, 1 cm distal to the common carotid artery. The external carotid artery was ligated and a common carotid to internal carotid artery bypass was done with a reversed saphenous vein graft. He recovered well in the postoperative period and was discharged on day 7. Pseudoaneurysm formation following carotid body tumor resection is extremely rare and has only been reported thrice in the literature.

Resumo Um homem de 47 anos apresentou tumor carotídeo Shamblin tipo 2 no lado direito, medindo 5 x 5 cm. Após embolização pré-operatória, foi realizada ressecção subadventicial do tumor. O paciente teve alta no quinto dia pós-operatório e voltou à emergência 10 dias depois, com pseudoaneurisma hemorrágico no sítio operatório causando disfagia e dispneia. Foi levado para exploração emergencial da ferida cirúrgica, e, no intraoperatório, 1 cm distalmente à artéria carótida comum, as extremidades proximais da artéria carótida interna e da artéria carótida externa próximas à bifurcação formavam um pseudoaneurisma. A artéria carótida externa foi ligada, e foi realizada uma ponte de safena de carótida comum para a artéria carótida interna com a veia safena invertida. O paciente se recuperou bem no pós-operatório e recebeu alta no sétimo dia. A formação de pseudoaneurisma após ressecção de tumor do corpo carotídeo é extremamente rara, tendo sido relatada apenas três vezes na literatura.

Enhanced Peripheral Chemoreflex Drive Is Associated with Cardiorespiratory Disorders in Mice with Coronary Heart Disease.

Coronary heart disease (CHD) is a prevalent cardiovascular disease characterized by coronary artery blood flow reductions caused by lipid deposition and oxidation within the coronary arteries. Dyslipidemia is associated with local tissue damage by oxidative stress/inflammation and carotid bodies (CB) peripheral chemoreceptors are heavily modulated by both reactive oxygen species and pro-inflammatory molecules (i.e., cytokines). Despite this, it is not know whether CB-mediated chemoreflex drive may be affected in CHD. In the present study, we evaluated peripheral CB-mediated chemoreflex drive, cardiac autonomic function, and the incidence of breathing disorders in a murine model of CHD. Compared to age-matched control mice, CHD mice showed enhanced CB-chemoreflex drive (twofold increase in the hypoxic ventilatory response), cardiac sympathoexcitation, and irregular breathing disorders. Remarkably, all these were closely linked to the enhanced CB-mediated chemoreflex drive. Our results showed that mice with CHD displayed an enhanced CB chemoreflex, sympathoexcitation, and disordered breathing and suggest that CBs may be involved in chronic cardiorespiratory alterations in the setting of CHD.

Role of Peripheral Chemoreceptors on Enhanced Central Chemoreflex Drive in Nonischemic Heart Failure.

Heart failure (HF) is a prevalent disease in elderly population. Potentiation of the ventilatory chemoreflex drive plays a pivotal role in disease progression, at least in part, through their contribution to the generation/maintenance of breathing disorders. Peripheral and central chemoreflexes are mainly regulated by carotid body (CB) and the retrotrapezoid nuclei (RTN), respectively. Recent evidence showed an enhanced central chemoreflex drive in rats with nonischemic HF along with breathing disorders. Importantly, increase activity from RTN chemoreceptors contribute to the potentiation of central chemoreflex response to hypercapnia. The precise mechanism driving RTN potentiation in HF is still elusive. Since interdependency of RTN and CB chemoreceptors has been described, we hypothesized that CB afferent activity is required to increase RTN chemosensitivity in the setting of HF. Accordingly, we studied central/peripheral chemoreflex drive and breathing disorders in HF rats with and without functional CBs (CB denervation). We found that CB afferent activity was required to increase central chemoreflex drive in HF. Indeed, CB denervation restored normal central chemoreflex drive and reduced the incidence of apneas by twofold. Our results support the notion that CB afferent activity plays an important role in central chemoreflex potentiation in rats with HF.

Contribution of Carotid Bodies on Pulmonary Function During Normoxia and Acute Hypoxia.

Carotid bodies (CBs) are main peripheral chemoreceptors involved in breathing regulation. Despite the well-known role played by CBs on breathing control, the precise contribution of CBs on the regulation of lung mechanics remains controversial. Accordingly, we study changes in lung mechanics in normoxia (FiO2 21%) and hypoxia (FiO2 8%) in mice with or without functional CBs. For this, we used adult male mice that underwent sham or CB denervation (CBD) surgery. Compared to sham-operated mice, we found that CBD induced an increase in lung resistance (RL) while breathing normoxic air (sham vs. CBD, p < 0.05). Importantly, changes in RL were accompanied by an approximately threefold reduction in dynamic compliance (Cdyn). Additionally, end-expiratory work (EEW) was increased in normoxia in the CBD group. Contrarily, we found that CBD has no effect on lung mechanics during hypoxic stimulation. Indeed, RL, Cdyn, and EEW values in CBD mice were undistinguishable from the ones obtained in sham mice. Finally, we found that CBD induces lung parenchyma morphological alterations characterized by reduced alveoli space. Together our results showed that CBD progressively increases lung resistance at normoxic conditions and suggest that CB tonic afferent discharges are needed for the proper regulation of lung mechanics at rest.

Carotid Body-Mediated Chemoreflex Function in Aging and the Role of Receptor-Interacting Protein Kinase.

Ventilatory impairment during aging has been linked to carotid body (CB) dysfunction. Anatomical/morphological studies evidenced CB degeneration and reductions in the number of CB chemoreceptor cells during aging. The mechanism(s) related to CB degeneration in aging remains elusive. Programmed cell death encompasses both apoptosis and necroptosis. Interestingly, necroptosis can be driven by molecular pathways related to low-grade inflammation, one hallmark of the aging process. Accordingly, we hypothesized that necrotic cell death dependent on receptor-interacting protein kinase-3 (RIPK3) may contribute, at least in part, to impair CB function during aging. Adult (3 months) and aged (24 months) wild type (WT) and RIPK3-/- mice were used to study chemoreflex function. Aging results in significant reductions in both the hypoxic (HVR) and hypercapnic ventilatory responses (HCVR). Adult RIPK3-/- mice showed normal HVR and HCVR compared to adult WT mice. Remarkable, aged RIPK3-/- mice displayed no reductions in HVR nor in HCVR. Indeed, chemoreflex responses obtained in aged RIPK3-/- KO mice were undistinguishable from the ones obtained in adult WT mice. Lastly, we found high prevalence of breathing disorders during aging and this was absent in aged RIPK3-/- mice. Together our results support a role for RIPK3-mediated necroptosis in CB dysfunction during aging.

Carotid body contribution to the physio-pathological consequences of intermittent hypoxia: role of nitro-oxidative stress and inflammation.

Obstructive sleep apnoea (OSA), characterized by chronic intermittent hypoxia (CIH), is considered to be an independent risk for hypertension. The pathological cardiorespiratory consequences of OSA have been attributed to systemic oxidative stress, inflammation and sympathetic overflow induced by CIH, but an emerging body of evidence indicates that a nitro-oxidative and pro-inflammatory milieu within the carotid body (CB) is involved in the potentiation of CB chemosensory responses to hypoxia, which contribute to enhance the sympathetic activity. Accordingly, autonomic and cardiovascular alterations induced by CIH are critically dependent on an abnormally heightened CB chemosensory input to the nucleus of tractus solitarius (NTS), where second-order neurons project onto the rostral ventrolateral medulla (RVLM), activating pre-sympathetic neurons that control pre-ganglionic sympathetic neurons. CIH produces oxidative stress and neuroinflammation in the NTS and RVLM, which may contribute to the long-term irreversibility of the CIH-induced alterations. This brief review is mainly focused on the contribution of nitro-oxidative stress and pro-inflammatory molecules on the hyperactivation of the hypoxic chemoreflex pathway including the CB and the brainstem centres, and whether the persistence of autonomic and cardiorespiratory alterations may depend on the glial-related neuroinflammation induced by the enhanced CB chemosensory afferent input.

Paraganglioma gigante del espacio parafaríngeo en una fémina / Giant paraganglioma of the parapharingeal space in a woman: en

Se describe el caso clínico de una paciente de 57 años de edad, con antecedente de hipertensión arterial, quien fue asistida en el Servicio de Cirugía de Cabeza y Cuello del Instituto Nacional de Oncología y Radiobiología de La Habana, remitida de la consulta de Otorrinolaringología de su hospital de cabecera por presentar manifestaciones clínicas de disfagia y diagnóstico clínico de sospecha de un paraganglioma carotídeo. Luego de realizados el examen físico y los estudios complementarios pertinentes, el caso fue discutido por los integrantes de un equipo multidisciplinario y se confirmó la existencia de un paraganglioma del espacio parafaríngeo, por lo que se decidió realizar tratamiento quirúrgico. La evolución fue satisfactoria y a los 2 años del procedimiento quirúrgico no presentaba secuelas.

The case report of a 57 years patient with history of hypertension is described who was assisted in the Head and Neck Surgery Service of the National Institute of Oncology and Radiobiology in Havana, referred from the Otolaryngology Service of her head hospital due to clinical manifestations of dysphagia and suspected clinical diagnosis of a carotid paraganglioma. After the physical exam and the pertinent complementary studies, the case was discussed by the members of a multidisciplinary team and the existence of a paraganglioma in the parapharingeal space was confirmed, therefore it was decided to carry out surgical treatment. The clinical course was satisfactory, and 2 years after the surgical procedure there were no sequels.

Microsurgical treatment of carotid body tumors using periadventitial dissection: Analysis of outcomes and prognostic factors in a neurological referral center.

Background: Surgical resection for carotid body tumors (CBTs) is the gold standard of treatment and continues to be a challenging procedure, commonly associated with high vascular injury rates and neurological complications. Methods: It is a retrospective case series study between January 2002 and November 2020, with a mean follow-up of 29 months in a single nationwide referral center. Thirty-one patients diagnosed with a carotid body tumor and treated with microsurgical periadventitial resection were included in the study. Patients' demographics, comorbidities, clinical, radiological factors, and tumor grade, evaluated by the Shamblin scale, were obtained. Statistical analysis was performed on all collected data. Results: In this study, we included 31 patients (32 tumors), 80% of the patients were female, and 20% were male, with a mean age of 53 years. One patient presented with bilateral lesions, while 17 tumors were located on the left side. The most frequent symptom was a painless, slow-growing neck mass in 74% of patients. Using the Shamblin classification, 13% of tumors were Grade I, 53% Grade II, and 34% Grade III. In the postoperative period, 3% of patients presented with permanent cranial nerve deficit, while none had vascular injuries or postoperative stroke. A tumor >5 cm increased the risk for nerve lesion by 11 times (OR 12.6, CI 95% 7.4-11.4, P < 0.001). Conclusion: Preoperative embolization followed by periadventitial resection by means of a microsurgical technique is a safe and effective approach to remove CBT, with 3% cranial nerve injury rate and no need for vascular sacrifice or reconstruction.

The carotid body: A novel key player in neuroimmune interactions.

The idea that the nervous system communicates with the immune system to regulate physiological and pathological processes is not new. However, there is still much to learn about how these interactions occur under different conditions. The carotid body (CB) is a sensory organ located in the neck, classically known as the primary sensor of the oxygen (O2) levels in the organism of mammals. When the partial pressure of O2 in the arterial blood falls, the CB alerts the brain which coordinates cardiorespiratory responses to ensure adequate O2 supply to all tissues and organs in the body. A growing body of evidence, however, has demonstrated that the CB is much more than an O2 sensor. Actually, the CB is a multimodal sensor with the extraordinary ability to detect a wide diversity of circulating molecules in the arterial blood, including inflammatory mediators. In this review, we introduce the literature supporting the role of the CB as a critical component of neuroimmune interactions. Based on ours and other studies, we propose a novel neuroimmune pathway in which the CB acts as a sensor of circulating inflammatory mediators and, in conditions of systemic inflammation, recruits a sympathetic-mediated counteracting mechanism that appears to be a protective response.

Physiological and clinical impact in the carotid baroreceptor function following the surgical management of bilateral carotid body tumors.

OBJECTIVE: The bilateral presentation of Carotid Body Tumors (CBT) is rare; the surgical resection of these masses remains the mainstay management due to the malignant potential. We aim to describe, classify, and quantify baroreceptor failure (BRF) after the surgical management of patients with bilateral CBT to better understand the clinical consequences. METHODS: Retrospective review of patients that underwent bilateral CBT resection to assess the changes in baroreceptor function. We describe the clinical events associated to BRF after surgery, baseline patient's demographics, characteristics, comorbidities. Additionally, clinical and a quantitative evaluation of baroreceptor sensitivity were conducted using the Composite Autonomic Severity Score (CASS). RESULTS: From 1986 to 2020, a total 146 CBT resections were performed in 132 patients in our institution. Tumors were removed bilaterally in staged procedures in seven patients with a mean age of 61 years (Standard Deviation 11), six (85%) were females, and there was no family history of paragangliomas. The clinical presentation were palpable masses in 5 (71%), and odynophagia in 2 (29%) cases; malignant histopathology following surgery was found in one case. BRF occurred in one patient after unilateral CBT resection, consisting of bradycardia and a 40 s asystole that was not previously associated to BR sensitivity. Three (43%) patients presented BRF in the immediate postoperative period of the contralateral CBT excision, consisting of volatile hypertensive crisis in two cases, and supraventricular tachycardia in one. All the patients developed (100%) chronic baroreceptor sensitivity symptoms consisting in syncope, vertigo and fatigue in 4 (57%), tachycardia in 2 (28%), and orthostatic headache in one (14%). Autonomic testing showed mixed sympathetic and parasympathetic failure in five (71%), severe sympathetic failure in 1 (14%), and parasympathetic dysfunction in one patient (14%). CONCLUSIONS: Postoperative autonomic assessment confirmed BRF in all studied patients that underwent staged bilateral CBT resection with mixed, sympathetic, and parasympathetic dysfunction. Further studies are necessary to evaluate the incidence and physiological mechanisms of these sequelae to anticipate possible complications and offer the appropriate perioperative management.

Luschka and the carotid body / Luschka e o corpo carotídeo

The 'carotid body' is a small structure sited at the bifurcation of the common carotid artery. The macroscopic features of the carotid body, and items of the extrinsic nervous, and vascular supplies, were initially described by Taube (1743), complemented by a number of authors that followed, proceeding until Luschka (1962), who added the first microscopic study. The macroscopic features of the carotid body, including location, extrinsic innervation, and vascular supply, then provided, were described in a relatively satisfactory manner. However, despite Luschka's great and admirable effort, the microscopic findings seem to be flawed, what can be ascribed to the technical limitations at the time, and the artifacts due to the used procedures. Nevertheless, there is no doubt that Luschka and his forerunners provided an important step for forthcoming research on the carotid body, and its innervation.

O 'corpo carotídeo' é uma pequena estrutura situada na bifurcação da artéria carótida comum. Os aspectos macroscópicos do corpo carotídeo e itens sobre o suprimento nervoso e vascular extrínsecos foram descritos inicialmente por Taube (1743), complementados por um certo número de autores que seguiram, prosseguindo até Luschka (1962), que acrescentou o primeiro estudo microscópico. Os aspectos macroscópicos do corpo carotídeo, incluindo localização, inervação extrínseca e suprimento vascular, então providos, foram descritos de modo relativamente satisfatório. Entretanto, apesar do grande e admirável esforço de Luschka, os achados microscópicos aparecem falhos, o que pode ser atribuído às limitações técnicas daquele tempo e a artefatos devidos aos procedimentos utilizados. Todavia, não há dúvida que Luschka e seus precursores proveram um importante passo para pesquisas que vieram sobre o corpo carotídeo e da sua inervação.