Single-cell transcriptome analysis reveals tumoral microenvironment heterogenicity and hypervascularization in human carotid body tumor.

Carotid body tumor (CBT) is a rare neck tumor located at the adventitia of the common carotid artery bifurcation. The prominent pathological features of CBT are high vascularization and abnormal proliferation. However, single-cell transcriptome analysis of the microenvironment composition and molecular complexity in CBT has yet to be performed. In this study, we performed single-cell RNA sequencing (scRNA-seq) analysis on human CBT to define the cells that contribute to hypervascularization and chronic hyperplasia. Unbiased clustering analysis of transcriptional profiles identified 16 distinct cell populations including endothelial cells (ECs), smooth muscle cells (SMCs), neuron cells, macrophage cells, neutrophil cells, and T cells. Within the ECs population, we defined subsets with angiogenic capacity plus clear signs of later endothelial progenitor cells (EPCs) to normal ECs. Two populations of macrophages were detectable in CBT, macrophage1 showed enrichment in hypoxia-inducible factor-1 (HIF-1) and as well as an early EPCs cell-like population expressing CD14 and vascular endothelial growth factor. In addition to HIF-1-related transcriptional protein expression, macrophages1 also display a neovasculogenesis-promoting phenotype. SMCs included three populations showing platelet-derived growth factor receptor beta and vimentin expression, indicative of a cancer-associated fibroblast phenotype. Finally, we identified three types of neuronal cells, including chief cells and sustentacular cells, and elucidated their distinct roles in the pathogenesis of CBT and abnormal proliferation of tumors. Overall, our study provided the first comprehensive characterization of the transcriptional landscape of CBT at scRNA-seq profiles, providing novel insights into the mechanisms underlying its formation.

Prevalence, characteristics, evaluation, and management of carotid body tumors: Systematic analysis based on available evidence.

OBJECTIVE: Although carotid body tumors (CBTs) are rare, they attract particular attention because of their propensity for malignant transformation and the high surgical risk. Because data are scarce and as it is difficult to achieve a large sample size, no study has yet comprehensively analyzed the characteristics, management, or operative complications of CBTs. Therefore, we collected and analyzed all currently available information on CBTs and used the pooled data to derive quantitative information on disease characteristics and management. METHODS: We systematically searched PubMed, Embase, the Cochrane Library, and the Web of Science up to December 1, 2022, for studies that investigated the characteristics and management of CBTs. The primary objective was to identify the prevalence of the various characteristics and the incidence of complications. The secondary objective was to compare patients who underwent preoperative embolization (PE) and those who did not (non-PE), as well as to compare patients with different Shamblin grades and those with and without succinate dehydrogenase (SDH) mutations in terms of CBT characteristics and complications. Two reviewers selected studies for inclusion and independently extracted data. All statistical analyses were performed using the standard statistical procedures of Review Manager 5.2 and Stata 12.0. RESULTS: A total of 155 studies with 9291 patients and 9862 tumors were identified. The pooled results indicated that the median age of patients with CBT was 45.72 years, and 65% were female. The proportion of patients with bilateral lesions was 13%. In addition, 16% of patients had relevant family histories, and the proportion of those with SDH gene mutations was 36%. Sixteen percent of patients experienced multiple paragangliomas, and 12% of CBTs had catecholamine function. The incidence of cranial nerve injury (CNI) was 27%, and 14% of patients suffered from permanent CNI. The incidence rates of operative mortality and stroke were both 1%, and 4% of patients developed transient ischemic attacks. Of all CBTs, 6% were malignant or associated with metastases or recurrences. The most common metastatic locations were the lymph nodes (3%) and bone (3%), followed by the lungs (2%). Compared with non-PE, PE reduced the estimated blood loss (standardized mean difference, -0.95; 95% confidence interval [CI], -1.70 to -0.20) and the operation time (standardized mean difference, -0.56; 95% CI, -1.03 to -0.09), but it increased the incidence of stroke (odds ratio, 2.44; 95% CI, 1.04-5.73). Higher Shamblin grade tumors were associated with more operative complications. Patients who were SDH gene mutation-positive were more likely to have a relevant family history and had more symptoms. CONCLUSIONS: CBT was most common in middle-aged females, and early surgical resection was feasible; there was a low incidence of serious operative complications. Routine PE is not recommended because this may increase the incidence of stroke, although PE somewhat reduced the estimated blood loss and operation time. Higher Shamblin grade tumors increased the incidence of operative complications. Patients who were SDH gene mutation-positive had the most relevant family histories and symptoms.

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.

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.

Fifteen Years of Experience with Surgical Management of Bilateral Non-familial Carotid Body Tumors.

BACKGROUND: Bilateral carotid body tumors (CBTs) clinical manifestation is infrequent. We conducted this work to describe our experience in the surgical treatment of bilateral CBT and to analyze our results. METHODS: A retrospective, observational study. We analyzed the totality of bilateral CBT resections that had been performed in our institution from January 2008 to September 2023. Data was obtained from medical records and anonymized, ethics approval was obtained from our institution committee. As the number of observations was less than those required by the central limit theorem our sample was considered nonparametric. Statistical analysis was performed on Stata 17. RESULTS: We evaluated 16 patients with a total of 32 CBT; surgical resection was performed in 28 cases (87.50%). Median age of the patients was 60 years (interquartile range [IQR] 46-64). Regarding the Shamblin classification, 9 CBTs (32.14%) were classified as Shamblin I, 11 (39.29%) as Shamblin II, and 8 (28.57%) as Shamblin III. The median Distance to the Base of the Skull (DTBOS) was 3.5 cm (IQR 2.7-5.1), and the median tumor volume was 11.25 cc (IQR 3.4-18.7). The median bleeding volume was 300 ml (IQR 200-500), and the median surgical time was 190 min (IQR 145-240). All surgeries were performed using the Retrocarotid Dissection technique. We documented 9 (32.14%) cases of nerve injuries, all of which were transitory. In the median regression a statistically significant association was found between DTBOS, Shamblin classification and tumor volume with intraoperative bleeding and length of stay. CONCLUSIONS: Surgical treatment remains safe and should be considered the gold standard for accurate histologic diagnosis. DTBOS and tumor volume, in addition to Shamblin classification, must be considered in preoperative planning to predict bleeding and hospital stay.

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.

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.

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.

Clinical outcomes and challenges of surgical extirpation for carotid body paraganglioma in South Korea: a single-center retrospective study.

BACKGROUND: Carotid body paraganglioma (CBP) is a rare, highly vascularized, and slow-growing neuroendocrine tumor. Surgical resection is the definitive treatment for CBP, however, it remains challenging due to the tumor's proximity to critical blood vessels and cervical cranial nerves. This study aimed to document the characteristics of CBP and examine the clinical outcomes of patients following surgical extirpation of CBP. METHODS: This is a single-center retrospective review analyzed patients who underwent CBP extirpation. We examined the patient demographics, preoperative clinical features, tumor characteristics, levels of catecholamines and their metabolites in the serum and urine. Surgeries were performed by one vascular surgeon with follow-ups at 1,3,6 months and yearly thereafter. Logistic regression analysis was conducted to identify risk factors associated with the occurrence of either permanent or temporary cervival cranial nerve palsy (CNP). RESULTS: From September 2020 to February 2023, this study examined 21 cases of CBP removal surgeries that were carried out in 19 patients. The mean age of the patients was 38.9 ± 10.9 years and the percentage of males was 57.1% (n = 12). The most common preoperative clinical feature was painless neck mass (n = 12; 57.1%). Complete resection was achieved in 20 cases; excluding one case with pathologically proven sclerosing paraganglioma. Vascular procedures were performed in four cases (ECA resection, n = 2; primary repair of ICA tear without carotid shunting, n = 1; and ICA patch angioplasty with carotid shunting, n = 1). Temporary cranial neurologic complications, specifically aspiration and hoarseness occurred in four (19.0%), and three (14.3%) cases, respectively. Hoarseness associated with permanent CNP persisted for more than 6 months in two cases (9.5%). No recurrence or mortality was observed during the follow-up period. CONCLUSIONS: Surgical resection is the primay treatment approach for CBP; however, it poses risks of vascular or cervical CNP. The intraoperative estimated blood loss was the only identified risk factor for CNP.

Molecular basis of carotid body tumor and associated clinical features in Japan identified by genomic, immunohistochemical, and clinical analyses.

Carotid body tumor (CBT) is classified as a paraganglioma (PGL). Here, we report the genetic background, protein expression pattern, and clinical findings of 30 Japanese CBT cases. Germline pathogenic or likely pathogenic (P/LP) variants of genes encoding succinate dehydrogenase subunits (SDHs) were detected in 15 of 30 cases (50%). The SDHB variants were the most frequently detected, followed by SDHA and SDHD variants. One case with SDHAF2 variant was bilateral CBT, and other two multiple PGL cases were not detected P/LP variants. The three cases with germline variants that could be tested did not have somatic P/LP variants of the same genes. Immunohistochemical analysis showed negative SDHB signals in CBT tissues in five cases with germline P/LP variants of SDHB, SDHD, or SDHA. In addition, SDHB signals in CBT tissues were negative in four of nine cases without germline P/LP variants of SDHs. These findings suggest the involvement of unidentified molecular mechanisms affecting SDHs.

An analysis from the CAPACITY database of outcomes of preoperative embolization before carotid body tumor surgery compared with resection alone.

OBJECTIVE: There is no definitive consensus on the impact of preoperative embolization on carotid body tumor (CBT) treatment. The objective of this study was to compare surgical outcomes of patients who underwent preoperative embolization before CBT resection vs patients who underwent resection alone. METHODS: The CAPACITY registry included 1432 patients with CBT from 11 medical centers in four different countries. The group of patients undergoing CBT resection with preoperative embolization was matched in a 1:6 ratio from a pool of patients from the CAPACITY database, using a generated propensity score with patients who did not underwent preoperative embolization. RESULTS: A total of 553 patients were included for analysis. Mean patient age was 56.23 ± 12.22 years. Patients were mostly female (n = 469; 84.8%). Bilateral CBT was registered in 60 patients (10.8%). Seventy-nine patients (14.3%) underwent preoperative embolization. Embolized patients had larger CBT sizes than non-embolized patients (33.8 mm vs 18.4 mm; P = .0001). Operative blood loss was lower in the embolized group compared with the non-embolized group (200 mL vs 250 mL; P = .031). Hematomas were more frequent in the non-embolized group (0% vs 2.7%; P = .044). Operative time, rates of stroke, cranial nerve injuries, and death were not statistically significant between groups. CONCLUSIONS: Embolization before CBT resection was associated with significantly lower blood loss and lower neck hematomas than patients who underwent resection alone. Operative time, stroke, cranial nerve injuries, and death were similar between groups.

Effect of distance to the base of skull and tumor size characteristics on cranial nerve injuries in carotid body tumor resections.

OBJECTIVE: In the present study, we aimed to confirm the findings reported by Kim et al. They stated that the tumor's distance to the base of the skull was predictive of injury to the cranial nerves and their branches during carotid body tumor resection in an Austrian cohort. METHODS: In the present retrospective observational trial, we included all consecutive patients who had been discharged from our tertiary care teaching hospital with the diagnosis of a carotid body tumor (CBT) between January 2004 and December 2019. Tumor-specific parameters were measured from the preoperative contrast-enhanced computed tomography or magnetic resonance imaging studies. Patient-specific data were obtained from the patients' medical records. The effect of these parameters on the occurrence of cranial nerve injuries was calculated using univariate logistic regression analysis. Parameters significant on univariate analysis were included in a multivariate model. RESULTS: A total of 48 CBTs had been resected in 43 patients (29 women [67.4%] and 14 men [32.6%]), with a mean age of 55.6 years (95% confidence interval, 51.8-58.5). The mean distance to the base of the skull was 43.2 mm (95% confidence interval, 39.9-46.5). A total of 18 injuries to the cranial nerves and their branches in 10 CBTs were detected. The tumor-specific parameters that were significant on univariate analysis were the distance to the base of the skull (P = .009), craniocaudal tumor diameter (P = .027), and tumor volume (P = .036). Stepwise multivariate logistic regression analysis revealed that the distance to the base of the skull was the only parameter that remained statistically significant. CONCLUSIONS: We found that the distance to the base of the skull is a highly predictive parameter for injuries to the cranial nerves and their branches during CBT resection and should be included in the surgical risk assessment and patient information.

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.

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.

Morbidity and Long-Term Patient-Reported Outcomes Following Advanced Carotid Body Tumor Resection.

BACKGROUND: The reported risk of a cranial nerve (CN) injury is up to 1 in 4 patients in large registries of carotid body tumor (CBT) resection. Functional outcome for this population is unknown. METHODS: We evaluated consecutive patients who underwent CBT resection from November 2013 through October 2020. Demographics, intraoperative details, complications, and outcomes were recorded from the medical record. Permanent CN nerve injury was defined as deficits lasting >6 months. Frequency statistics, averages, chi-squared test, and multiple logistic regression were completed for primary end points of complications and disease-free survival. Patient-reported outcomes were gathered via telephone survey of patients conducted in September 2021. RESULTS: Fifty-one patients presented with CBTs and the following Shamblin classes: I (n = 7; 14%), II (n = 36; 69%), and III (n = 9; 17%). Head and neck oncology and vascular surgery jointly did 52% of CBT resections, including 6 of 9 Shamblin III cases. Eight patients (15.3%, all Shamblin II or III) suffered a total of 12 CN injuries - 8 CN XII (5 temporary and 3 permanent), 3 CN X (all permanent), and 1 CN XI (permanent). Seven of the CN injury subgroup had preoperative embolization and 5 were joint oncology/vascular cases. In addition, 4 separate carotid injuries required repair. Notably, all patients had disease-free survival postoperatively at a mean follow-up of 6 months. Patient-reported outcomes obtained in 70.6% of patients 1 year or more from index operation demonstrated that two-thirds of patients live without any permanent functional deficits, and the majority of those with continued deficits rate the symptoms as daily but mild in severity. CONCLUSIONS: In a series of complex CBT patients treated with preoperative embolization capabilities and multidisciplinary surgical approach, disease-free survival was achieved in all patients despite a high rate of iatrogenic CN injuries, most commonly CN XII. Patient-reported outcomes survey results indicate that injuries identified on clinical exam underreport patients' true postoperative CN deficits - especially branches of CN X. This data support the practice of aggressive primary resection of CBTs while providing guidance for expected functional outcomes due to CN injury risk.

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.

Risk Factors for Stroke After Carotid Paraganglioma Surgery.

BACKGROUND: The Carotid Paraganglioma Cooperative International Registry (CAPACITY) is an international registry composed of 1,432 patients with carotid body tumors (CBT) from 11 centers from 4 countries. The aim of this study was to identify risk factors for patients who presented stroke after carotid paraganglioma resection. METHODS: Clinical characteristics and demographics of patients who presented transoperatively and postoperatively stroke from the CAPACITY database were retrospectively gathered. Regression analysis was performed using single logistic regression with Omnibus' test for possible factors that might contribute to present stroke. RESULTS: Out of 1,432 patients, 8 (0.5%) female patients presented stroke. Median age was 53 years (range: 41-70 years). Six strokes occurred transoperatively, diagnosed clinically in the immediate postoperative period. Of them, none of the patients received any further treatment. Three of them died on postoperative day 2, 3, and 4. Two patients developed stroke during the first 24 postoperative hours, patients showed dysarthria, and aphasia. One of them was reintervened with thrombectomy due to thrombosis of the common carotid artery the other patient was treated conservatively. Median follow-up was 16 months (range: 2-72 months). Single logistic regression analysis revealed a history of diabetes mellitus (odds ratio (OR) 7.62), carotid artery disease (OR 17.51), and vascular lesion (OR 2.37) to have significantly increased odds of stroke during CBT surgery. CONCLUSIONS: In the present study history of diabetes mellitus, carotid artery disease, and vascular lesion had increased odds of stroke during CBT surgery. Findings are limited by low event rate and even larger cohorts are needed to fully define preventive preoperative strategies for preventing stroke.

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).

Epidemiology and survival of patients with malignant carotid body tumors in the SEER database.

OBJECTIVE: The objective of this study was to investigate population-based epidemiology, survival outcomes, and prognostic factors of malignant carotid body tumors (CBTs). METHODS: Patients with malignant CBTs who were diagnosed between 1975 and 2018 were screened from nine registries of the Surveillance, Epidemiology, and End Results (SEER) database. Cases that were coded as "carotid body tumor, malignant" or malignant tumors with the primary site recorded as "carotid body" were screened for inclusion in the study. The incidence of malignant CBT was calculated with SEER∗Stat software. Survival outcomes were analyzed using the Kaplan-Meier method and log-rank tests. RESULTS: A total of 72 patients with malignant CBT were screened for inclusion in the study, including 41 females (56.9%) and 31 males (43.1%). Based on the SEER program data, the incidence of malignant CBT was found to fluctuate between 0 to 0.02 cases per 100,000 people per year, with a slow but noticeable uptick after 1990. The most commonly affected populations included women and patients between the ages of 35 and 44, which accounted for 59.9% and 27.8% of patients in the study, respectively. During a median follow-up of 82 months, four patients were lost to follow-up, and 28 deaths were identified. Of those, 20 were considered disease-specific deaths. Further analysis found that the 5-year and 10-year overall survival rates were 78.9% and 67.8%, respectively, whereas the 5-year and 10-year disease-specific survival rates were 84.5% and 75.2%, respectively. The Kaplan-Meier method and log-rank tests indicated that age <50 years, sex, race, tumor number, and surgical treatment were unrelated to both overall survival and disease-specific survival. CONCLUSIONS: A retrospective review of the SEER database found that the incidence of malignant CBT was extremely rare and prone to fluctuation, but that it slowly trended upward over time. Malignant CBT was found to more likely affect females, and it could be diagnosed at any age. The overall prognosis for malignant CBT appeared to be good, with acceptable 5-year and 10-year survival rates. Due to a number of factors complicating malignant CBT surgery, surgical treatment should be considered with caution.

Paragangliomas of the head and neck.

Paragangliomas are rare neuroendocrine tumors that can be found from the skull base to the pelvis. Head and neck paragangliomas have been historically treated with surgery. However, surgical resection adds risk of injury to vascular structures and cranial nerves that can lead to morbidity such as hoarseness, dysarthria, dysphagia, or aspiration. Recently, improved understanding of the behavior of these tumors and increasing experience in non-surgical treatments, such as observation and radiation therapy, have changed the paradigms of management of this entity. Multiple series now show a trend toward a more conservative management, with a higher percentage of patients being observed or treated with radiotherapy. Several factors should be taken into consideration when deciding the most appropriate treatment for head and neck paragangliomas, starting by differentiating carotid body tumors from non-carotid body tumors. In general, surgical resection is normally recommended for carotid body tumors as the complications from treatment are usually minimal. In contrast, for non-carotid body tumors, surgery is often associated with significant functional impairment due to cranial nerve paralysis. As such, non-surgical treatment is now usually recommended for this subset of head and neck paragangliomas. In young patients with no comorbidities and a small to medium carotid body tumors, surgery should be considered. Moreover, surgery should be offered for secreting tumors, malignant tumors, tumors with rapid growth or increase in symptomatology, and when radiotherapy cannot be performed. Conversely, conservative management with active surveillance or radiotherapy can be offered in the remaining cases in order to avoid unnecessary morbidity while still providing acceptable tumor control.