Novel insights into the classification of Shamblin III carotid body tumors from a neurosurgical perspective.

BACKGROUND AND PURPOSE: The classic Shamblin system fails to provide valuable guidance in many Shamblin's III carotid body tumors (III-CBTs) due to the variable forms of carotid arteries and the complex anatomic relationships in parapharyngeal space. We proposed a modified classification to separately divide III-CBTs into different subgroups on the basis of arterial relevant features and anatomical relevant features. MATERIALS AND METHODS: From 2020 to 2023, a total of 129 III-CBTs at a single institution were retrospectively analyzed. All cases were independently classified as arterial-relevant and anatomical-relevant subgroups. The pre-, peri- and postoperative data were summarized and compared accordingly. RESULTS: Among the 129 cases, 69 cases were identified as "Classical type", 23 cases as "Medial type", 27 cases as "Lateral type" and 10 cases as "Enveloped type" according to arterial morphologies. Besides, 76 cases were identified as "Common type", 15 cases as "Pharynx- invasion type", 18 cases as "Skull base-invasion type" and 20 cases as "Mixed type" according to anatomical relationships. "Enveloped type" of tumors in arterial-relevant classification and "Mixed type" of tumors in anatomical-relevant classification are the most challenging cases for surgeons with the lowest resection rate, highest incidence of carotid arteries injury and postoperative stroke. CONCLUSION: The modified classifications provide comprehensive understanding of different III-CBTs which are applicable for individualized treatment in clinical practice.

Malignant carotid body tumors: What we know, what we do, and what we need to achieve. A systematic review of the literature.

Malignant carotid body tumors (MCBT) are rare and diagnosed after detection of nodal or distant metastases. This systematic review (SR) focuses on MCBT initially approached by surgery. Preferred Reporting Items for SR and Meta-Analysis (MA) guided the articles search from 2000 to 2023 on PubMed, Scopus, and Web of Science. Among 3548 papers, 132 (337 patients) were considered for SR; of these, 20 (158 patients) for MA. Malignancy rate was 7.3%, succinate dehydrogenase (SDH) mutation 17%, age at diagnosis between 4th and 6th decades, with a higher prevalence of females. MCBTs were mostly Shamblin III, with nodal and distant metastasis in 79.7% and 44.7%, respectively. Malignancy should be suspected if CBT >4 cm, Shamblin III, painful or otherwise symptomatic, at the extremes of age, bilateral, with multifocal disease, and SDHx mutations. Levels II-III clearance should be performed to exclude nodal metastases and adjuvant treatments considered on a case-by-case basis.

Assessing the safety and efficacy of EVOH Pre-Embolization in head and neck paraganglioma tumors: A comprehensive analysis of current literature.

BACKGROUND: Head and Neck Paragangliomas are characterized by having a rich blood supply. Presurgical embolization with Onyx as a neoadjuvant treatment is not a consensus regarding its efficacy and safety. Our study aimed to answer this matter through a single-arm meta-analysis. METHODS: We systematically reviewed 4 databases. Sixteen studies were described and suitable papers were selected for meta-analysis of estimated intraoperative blood loss (EBL), percentage of tumor devascularization, and complications associated with embolization. RESULTS: The study identified 198 patients with 203 tumors, aged between 8 and 70 years. Commonly reported symptoms included neck mass perception and cranial nerve impairment. Carotid Body Tumors were most prevalent (127, 62.5 %), followed by jugular (48, 23.6 %), or vagal (29, 14.2 %) tumors. Eight studies reported estimated intraoperative blood loss (EBL) averaging 261.89 ml (95 %CI: 128.96 to 394.81 ml). In an analysis of 9 studies, 99 % (95 %CI: 96 to 100 %) achieved 70 % or more devascularization, and 79 % (95 %CI: 58 to 100 %) achieved 90 % or more devascularization. Complications from endovascular procedures were observed in 3 % (95 %CI: 0 to 8 %) of 96 patients across 10 studies, including 4 facial nerve deficits. Eighteen postoperative neurological deficits were reported across 15 articles. CONCLUSION: Despite acknowledged limitations, with refined indications, EVOH, especially Onyx embolization may significantly bolster patient safety, decreasing EBL and easing surgical resection. Further research with larger studies will refine criteria, optimize techniques, and improve patient care and treatment outcomes in the management of head and neck paragangliomas.

The value of color doppler ultrasonography combined with computed tomography angiography and magnetic resonance angiography in the preoperative quantification and classification of carotid body tumors: a retrospective analysis.

BACKGROUND: Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) provide accurate vascular imaging information, but their use may be contraindicated. Color Doppler ultrasonography (CDU) provides simple, safe, noninvasive, and reproducible imaging. We therefore investigated the role of preoperative CDU combined with CTA and MRA in the quantification, typing, and diagnosis of carotid body tumors (CBTs). METHODS: We retrospectively analyzed patients with CBTs categorized into group A (type I [n = 1] and type II [n = 10]) or group B (type III [n = 56]) per the intraoperative Shamblin classification. CDU, CTA, and MRA characteristics of CBTs were observed, surgical results were correlated, and the diagnostic threshold of the CBT classification was calculated. RESULTS: CBTs were usually located at the common carotid artery bifurcation, encircling the carotid artery. An increased angle was found between the internal and external carotid arteries. On CDU, CBTs primarily presented as homogeneous hypoechoic masses with clear boundaries, rich flow signals, and a high-speed, low-resistance artery-like flow spectrum. CTA showed uniform or heterogeneous marked enhancement. MRA showed mixed T1 and slightly longer T2 signals and uniform or uneven obvious enhancement. With increases in the lesion size, amount of blood transfused, and operation time, the intraoperative classification level and possibility of skull-base invasion increased. When the maximum diameter of the lesion, the volume of the tumor, the distance between the upper margin of the tumor to the mastoid and the mandibular angle were 3.10 cm, 10.15 cm3, - 3.26 cm, and 0.57 cm, respectively, the largest Youden index was the best diagnostic boundary value for Shamblin type III tumors. CONCLUSIONS: CDU combined with CTA and MRA can accurately evaluate the size and classification of CBTs.

Outcomes and Predictors of Morbidity after Carotid Body Tumor Resection.

BACKGROUND: Carotid body tumors (CBTs) are uncommon neuroendocrine tumors at the carotid bifurcation treated with resection. The goal of this study was to examine patient outcomes after CBT resection and establish predictors of morbidity. METHODS: Patients undergoing CBT resection were identified from the National Surgical Quality Improvement Program (NSQIP) database over 11 years. Demographics, past medical history, preoperative labs, procedural details, morbidity and mortality were recorded. Multivariable logistic regression (MLR) analysis was performed to determine independent predictors of morbidity. RESULTS: From 2010 to 2020, 668 CBT resections were identified. The majority of patients were female (65%) and White (72%) with a mean age of 56 (standard deviation [SD] ± 16). Average body mass index (BMI) was 29.9 (SD ± 7.1). Arterial resection occurred in 81 patients (12%). 6% of patients experienced morbidity, most commonly re-operation (2.4%). Morbidity was more common in patients with higher BMI (33.1 vs. 29.7, P = 0.005), chronic obstruction pulmonary disease (10% vs. 1.9%, P = 0.012), higher American Society of Anesthesiologists (P = 0.005), and lower albumin (3.7 vs. 4, P = 0.016). Morbidity was not increased with arterial resection (P = 1) or based on length of operation (P = 0.169). Morbidity did not impact mortality (P = 0.06) though led to longer length of stay [LOS] (8 days vs. 2.4, P < 0.001). On MLR, preoperative BMI was the only risk factor for morbidity (odds ratio 1.06, 95% confidence interval 1.02-1.1, P = 0.005). CONCLUSIONS: CBT resection is very well tolerated with low stroke rates, morbidity, and mortality. Arterial resection leads to increased transfusion requirements and LOS but did not increase stroke rates, mortality, or overall morbidity. Within the NSQIP database, preoperative BMI was the only predictor of postoperative morbidity, which leads to significantly longer LOS.

Surgical Management of Carotid Body Tumors: Experience of Two Centers.

BACKGROUND: Carotid body tumors (CBTs) are rare but require surgical resection given their potential for growth and malignancy. For some surgical teams, tumor hypervascularity justifies preoperative embolization to facilitate resection and limit complications. The objective of our study was to evaluate 2 different practices of surgical resection with or without preoperative embolization in a 2-center cohort. METHODS: A consecutive series of patients who underwent CBT surgery, from January 2011 to June 2019, were divided into 2 groups, as to whether they were (embolized CBT [ECBT]) or not (nonembolized CBT [NECBT]) preoperatively embolized. Both groups were compared specifically according to the duration of operation, postoperative complications, and length of stay. RESULTS: Twenty-two patients with a mean age of 48.5 ± 14.3 years were included. In the series, 23 CBTs were resected: 13 were embolized preoperatively; the mean time between embolization and surgery was 2.62 ± 1.50 days. Both groups were comparable based on characteristics of population and tumor, with a mean size of 33.2 ± 11.9 mm. We noted a significant increase in operation duration in the ECBT group: 151 min (±40.9) vs. 87.0 min (±21); P < 0.01. There was no difference between the 2 groups regarding cranial nerve (50% vs. 46%; P = 1), sympathetic nervous system (20% vs. 23%; P = 1), or vascular nerve (20% vs. 23%; P = 0.18) complications. No cerebrovascular accident was identified. The length of stay was 3.60 days (±1.78) vs. 3.73 days (±1.19; P = 0.44). CONCLUSIONS: This study reflects the experience of 2 centers in the management of CBT which is a rare pathology with no standardized treatment. Our series showed no significant difference between the ECBT and NECBT groups regarding postoperative complications and length of hospital stay. The reduction in operating time in the NECBT group remains to be demonstrated.

Proteomics analysis of carotid body tumor revealed potential mechanisms and molecular differences among Shamblin classifications.

Carotid body tumors (CBTs) are a rare type of paraganglioma, and surgical resection is the only effective treatment. Because of the proximity of CBTs to the carotid artery, jugular vein, and cranial nerve, surgery is extremely difficult, with high risks of hemorrhage and neurovascular injury. The Shamblin classification is used for CBT clinical evaluation; however, molecular mechanisms underlying classification differences remain unclear. This study aimed to investigate pathogenic mechanisms and molecular differences between CBT types. In Shamblin I, II, and III tumors, differentially expressed proteins (DEPs) were identified using direct data-independent acquisition (DIA). DEPs were validated using immunohistochemistry. Proteomics profiling of three Shamblin subtypes differed significantly. Bioinformatics analysis showed that adrenomedullin signaling, protein kinase A signaling, vascular endothelial growth factor (VEGF) signaling, ephrin receptor signaling, gap junction signaling, interleukin (IL)-1 signaling, actin cytoskeleton signaling, endothelin-1 signaling, angiopoietin signaling, peroxisome proliferator-activated receptor (PPAR) signaling, bone morphogenetic protein (BMP) signaling, hypoxia-inducible factor 1-alpha (HIF-1α) signaling, and IL-6 signaling pathways were significantly enriched. Furthermore, 60 DEPs changed significantly with tumor progression. Immunohistochemistry validated several important DEPs, including aldehyde oxidase 1 (AOX1), mediator complex subunit 22 (MED22), carnitine palmitoyltransferase 1A (CPT1A), and heat shock transcription factor 1 (HSF1). To our knowledge, this is the first application of proteomics quantification in CBT. Our results will deepen the understanding of CBT-related pathogenesis and aid in identifying therapeutic targets for CBT treatment.

Predictors for postoperative cranial nerve complications in carotid body tumor resection: a retrospective cohort study.

INTRODUCTION: Carotid body tumors (CBTs) are slow-growing benign tumors. Therefore, surgical resection is considered in case of tumor growth. The timing of surgery is of the utmost importance as the risk of iatrogenic surgical complications increases when resecting larger tumors, whereas on the other hand, resections for asymptomatic small CBT should be prevented. The primary aim of this study was to identify which tumor size or dimension is most accurate to predict nerve injury in patients undergoing resection of a CBT. MATERIAL AND METHODS: This retrospective cohort study included patients who underwent surgical resection of CBT at the university hospital in South-Holland. Baseline patient characteristics and tumor measurements were retrieved from the medical records. The authors assessed how the different methods of measuring the size of the tumor were interrelated using Pearson correlation. Logistic regression was used to assess which variables were independently associated with nerve injury, including age at surgery, Shamblin classification, and those dimensions that captured different aspects of tumor size (rather than measuring the same as shown by high correlations) as possible independent variables. RESULTS: In 125 patients, 143 CBTs were resected whereof in 35 cases cranial nerve injury occurred, (transient in 16 cases and permanent in 19 cases). The risks for nerve injury increased with larger tumor size and the Shamblin classification. Logistic regression analysis showed that the anterior-posterior (AP) diameter significantly increased the odds of a nerve injury, a doubling for every 1 cm increase in AP diameter [odds ratio (95% CI) 2.12 (1.29-3.48), P =0.003]. CONCLUSION: This study shows that measured tumor size in the AP plane is a strong predictor for postoperative nerve injury of a CBT resection. This predictor can be used in the daily clinic to give insight in operative risks. More research is needed in order to select the most appropriate time window for CBT resection.

Preoperative embolization is necessary for large-volume carotid body tumor (≥ 6670 mm3) resection.

BACKGROUND: To investigate the impact of preoperative embolization (p-TAE) on CBT surgical resection and explore the optimal tumor volume for p-TAE of CBT resection. METHODS: This retrospective study reviewed 139 surgically excised CBTs. According to Shamblin classification, tumor volumes, and whether to carry out the p-TAE, the patients were classified into different groups. The demographic, clinical features, and the intraoperative and post-operative information about the patients were retrieved and analyzed from the patient records. RESULTS: A total of 139 CBTs was excised in 130 patients. According to the results of subgroup analysis, there were no significant differences in surgical time, blood loss, adverse events (AEs), and the revascularization when compared with non-embolization group (NEG) for type I, II, III, respectively (all p > 0.05) except for the surgical time in type I (p < 0.05). Then the X-tile program was employed and determine the cutoff point (tumor volume = 6670 mm3) for tumor volumes and blood loss. The average tumor volume was (29,782.37 vs. 31,345.10 mm3, p = 0.65) for embolization group (EG) and NEG. The mean surgical time (208.86 vs. 264.67 min, p > 0.05) and intraoperative blood loss (252.78 vs. 430.00 mL, p < 0.05) were less, and the incidence of revascularization required (35.56 vs. 52.38%, p > 0.05) and total complications (27.78 vs. 57.14%, p < 0.05) were lower in EG when compared with NEG (tumor volume ≥ 6670 mm3). However, the results were not statistically significant when the tumor size was less than 6670 mm3. No surgery-related mortality was observed during the follow-up. CONCLUSIONS: Preoperative selective embolization of CBT is an effective and safe adjunct for surgical resection, especially for Shamblin class II and III tumors (≥ 6670 mm3).

Carotid body paraganglioma: a case report.

A highly vascular glomus tumor that develops from the paraganglion cells of the carotid body is called a carotid body tumor (CBT), also known as a chemodectoma or carotid body paraganglioma (CBP). It is situated near the carotid bifurcation, where the external and internal carotid arteries splay out characteristically. We present a case of a 30-year-old woman who had a slightly tender, slightly pulsatile, and slightly ballotable swelling over the lateral aspect of the neck on the right side. The surgical resection of the tumor was done based on the diagnosis made on clinical-radiological investigations as a carotid body tumor further confirmed by a histopathological study. We also provide a summary of the research on carotid body tumors clinical and imaging manifestations, assessment, and therapy.

Study on the Influencing Factors of Short-Term Recovery of Neurological Symptoms after Carotid Body Tumor Resection.

OBJECTIVE: To compare the differences in the short-term recovery from neurological symptoms (SRN) (≤ 6 months) and clinical characteristics of patients with different Shamblin classifications carotid body tumor (CBT) resection and to analyze the risk factors affecting SRN after surgery. METHODS: Patients who underwent CBT resection between June 2018 and September 2022 were recruited. Perioperative factors and indicators of the nature of the tumor were recorded. The risk factors affecting SRN after CBT resection were analyzed using logistic regression analysis. RESULTS: Eighty-five patients (43.86 ± 12.7 years, 46 females) were included, 40 (47.06%) of whom exhibited SRN. Univariate logistic regression showed that preoperative symptoms, surgical side, bilateral posterior communicating artery (PcoA) opening, some indicators of tumor size, operative/anesthesia time, and Shamblin III classification were correlated with postoperative neurological prognosis (all p < 0.05). After adjusting for confounders, preoperative symptoms (OR, 5.072; 95% CI 1.027-25.052; p = 0.046), surgical side (OR, 0.025; 95% CI 0.003-0234; p = 0.001), bilateral PcoA opening (OR, 22.671; 95% CI 2.549-201.666; p = 0.005), distance from the tip of the C2 dens to the superior aspect (dens-CBT) (OR, 0.918; 95% CI 0.858-0.982; p = 0.013) and Shamblin III classification (OR, 28.488; 95% CI 1.986-408.580; p = 0.014) were correlated with postoperative neurological symptom recovery. CONCLUSION: Preoperative symptoms, surgical side (right), bilateral PcoA opening, a short dens-CBT and Shamblin III classification are risk factors affecting SRN after CBT resection. Early resection is recommended for small-volume CBTs without neurovascular compression or invasion to obtain SRN.

Long-Term Outcomes of Patients With Carotid and Aortic Body Tumors.

Chemodectomas are tumors derived from parasympathetic nonchromaffin cells and are often found in the aortic and carotid bodies. They are generally benign but can cause mass-effect symptoms and have local or distant spread. Surgical excision has been the main curative treatment strategy. The National Cancer Database was reviewed to study all patients with carotid or aortic body tumors from 2004 to 2015. Demographic data, tumor characteristics, treatment strategies, and patient outcomes were examined, split by tumor location. Kaplan-Meier survival estimates were generated for both locations. In total, 248 patients were examined, with 151 having a tumor in the carotid body and 97 having a tumor in the aortic body. Many variables were similar between both tumor locations. However, aortic body tumors were larger than those in the carotid body (477.80 ± 477.58 mm vs 320.64 ± 436.53 mm, p = 0.008). More regional lymph nodes were positive in aortic body tumors (65.52 ± 45.73 vs 35.46 ± 46.44, p <0.001). There were more distant metastases at the time of diagnosis in carotid body tumors (p = 0.003). Chemotherapy was used more for aortic body tumors (p = 0.001); surgery was used more for carotid body tumors (p <0.001). There are slight differences in tumor characteristics and response to treatment. Surgical resection is the cornerstone of management, and radiation can often be considered. In conclusion, chemodectomas are generally benign but can present with metastasis and compressive symptoms that make understanding their physiology and treatment important.

SDH deficiency is very common in carotid body paragangliomas: Genetic counseling and testing should be offered to all patients.

BACKGROUND: Collectively, germline pathogenic variants in succinate dehydrogenase (SDH) genes are the most common cause of hereditary paragangliomas. Loss of immunohistochemical expression of SDHB protein (termed SDH deficiency) occurs whenever there is biallelic inactivation of any SDH gene. We sought to estimate the prevalence of SDH deficiency in patients with carotid body paragangliomas. METHODS: We identified all carotid body paragangliomas that had undergone surgical excision at our institution over the last 30 years. If SDHB immunohistochemistry was not performed at the time of excision, it was performed on archived material. RESULTS: There were 64 carotid body paragangliomas identified in the 62 patients. Two-thirds of the patients were female, and 43 (67%) were SDH-deficient. CONCLUSION: Up to two-thirds of all carotid body paragangliomas are associated with SDH deficiency. Therefore, genetic testing and counseling should be offered to all patients with carotid body paragangliomas, regardless of age or family history.

Association of Complications During and After Carotid Body Tumor Resection with Tumor Size and Distance to the Base of Skull.

BACKGROUND: Depending on the size and location of the tumor, carotid body tumor (CBT) resection can come with various complications, mostly intraoperative bleeding, and cranial nerve injuries. In the present study, we aim to evaluate 2 fairly new variables, tumor volume, and distance to the base of the skull (DTBOS), with operative complications of CBT resection. METHODS: Patients who underwent CBT surgery in Namazi hospital from 2015 to 2019 were studied using standard databases. Tumor characteristics and DTBOS were measured via computed tomography or Magnetic resonance imaging. Outcomes, including intraoperative bleeding and cranial nerve injuries, along with perioperative data were collected. RESULTS: A total of 42 cases of CBT were evaluated with an average age of 53.21 ± 12.8 and mostly female (85.7%). Based on Shamblin scoring, 2 (4.8%) were classified as group I, 25 (59.5%) as group II, and 15 (35.7%) as group III. The amount of bleeding significantly increased with an increase in the Shamblin scores (P = 0.031; median: I: 45 cc; II: 250 cc, III: 400 cc). Also, there was a significant positive correlation between the size of the tumor and the estimated amount of bleeding (correlation coefficient = 0.660; P < 0.001), and also a significant reverse correlation with between bleeding and DTBOS (correlation coefficient = -0.345; P = 0.025). During the follow-up of the patients, 6 (14.3%) had abnormalities in their neurological evaluation. Receiver operating characteristic curve analysis revealed the size of tumor cutoff level 32.7 cm3 (3.2 cm radius) to be most predictive of postoperative neurological complication with an area under the curve = 0.83, sensitivity = 83.3%, specificity = 80.6%, a negative predictive value = 96.7%, and positive predictive value of 41.7%, and an accuracy of 81.0%. Furthermore, based on the predictive power of the models in our study, we demonstrated that a combination model including the tumor size, DTBOS, along with the Shamblin score had the most predictive power for neurological complications. CONCLUSIONS: By evaluating CBT size and DTBOS, paired with the use of the Shamblin classification, a better, more insightful understanding of possible risks and complications of CBT resection can be obtained, leading to deserved levels of patient care.

Retrospective Analysis of Carotid Body Tumor Surgical Management: Roles of Preoperative Image Investigation and Preoperative Embolization.

BACKGROUND: Carotid body tumors (CBT) surgery is a challenging procedure, and the role of embolization (EMB) in CBT surgery has remained unclear. This study is performed to analyze the management of CBTs, particularly the use of preoperative EMB and image features in minimizing surgical complications. METHODS: A total of 200 CBTs were identified among 184 medical records involving CBT surgery. Regression analysis was used to explore the prognostic predictors of cranial nerve deficit (CND), including image features. In addition, blood loss, operation times, and complication rates were compared between patients who had surgery only versus patients who had surgery along with preoperative EMB. RESULTS: Overall, 96 males and 88 females were identified for inclusion in the study, with a median age of 37.0 years. Computed tomography angiography (CTA) showed the presence of a tiny gap adjacent to the encasement of carotid vessels, which could help minimize carotid arterial injury. High-lying tumors that encased the cranial nerve were usually managed with synchronous cranial nerve resection. Regression analysis revealed that the incidence of CND was positively associated with Shamblin Ⅲ, high-lying, and a maximal CBT diameter of ≥ 5 cm. Among 146 EMB cases, 2 cases of intracranial arterial EMB occurred. No statistical difference was found between the EBM and non-EBM groups in terms of bleeding volume, operation time, blood loss, blood transfusion requirement, stroke, and permanent CND. Subgroup analysis revealed that EMB decreased CND in Shamblin III and low-lying tumors. CONCLUSIONS: CBT surgery should be performed with preoperative CTA to identify favorable factors for minimizing surgical complications. Shamblin Ⅲ or high-lying tumors, as well as CBT diameter, are predictors of permanent CND. EBM does not reduce blood loss or shorten operation time.

Role of pre-operative embolization in carotid body tumor surgery according to Shamblin classification: A systematic review and meta-analysis.

BACKGROUND: Pre-operative embolization prior to surgical resection of carotid body tumors was meant to decrease intraoperative blood loss and operative time. Yet, potential confounders such as different Shamblin classes have never been analyzed. Aim of our meta-analysis was to investigate effectiveness of a pre-operative embolization according to different Shamblin classes. METHODS: Five studies comprising 245 patients were included. A random effects model meta-analysis was conducted, and the I2 statistic was used to assessment for heterogeneity. RESULTS: Pre-operative embolization was associated with a significant reduction in blood loss (WM: 276.4 mL; 95% CI, 201.9-378.3, p < 0.01); an absolute mean reduction, though not statistically significant, was observed in both Shamblin 2 and 3 classes. No difference in operative time was found between the two strategies (WM: 192.0 min; 95% CI, 157.7-234.1, p = 1.0). CONCLUSIONS: Embolization proved an overall significant reduction in perioperative bleeding, which did not reach threshold for statistical significance when Shamblin classes were singularly considered.