Carotid Body Tumor Resection: Long-Term Outcome of 67 Cases without Preoperative Embolization

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

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.

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.

Current management of carotid body tumors

Carotid body tumors (CBTs) are neoplasms that occur at the bifurcation of the carotid artery and are pathologically classified as paragangliomas. In the 4th edition of the WHO classification, paragangliomas are categorized as neoplasms with malignant potential. Clinically, about 5% of CBTs present with malignant features such as metastasis. Currently, it is challenging to distinguish between tumors with benign courses and those that present malignantly. Recent advances in genetic testing have elucidated the genetic characteristics of paragangliomas, including carotid body tumors. Over 20 genes have been identified as being involved in tumor development. Particularly in head and neck paragangliomas, abnormalities in genes related to succinate dehydrogenase are frequently observed. Research is ongoing to understand the mechanisms by which these genes contribute to tumor development. The definitive treatment for CBTs is surgical resection. These tumors are prone to bleeding and often adhere firmly to the carotid artery, making intraoperative bleeding control challenging. The risk of lower cranial nerve paralysis is relatively high, and there is a risk of stroke because of manipulation of the carotid artery. Preoperative evaluation with angiography is essential, and a multi-disciplinary surgical team approach is necessary. In cases where the tumor is difficult to resect or has metastasized, radiation therapy or chemotherapy are employed. Clinical trials involving targeted molecular therapies and radiopharmaceuticals have recently been conducted, with some applied clinically. The development of various new treatments is anticipated, providing hope for therapeutic options in refractory cases.

Our Experience in Subadventitial Dissection vs. Intracapsular Dissection Technique of Carotid Body Tumors Surgery

This study provides a single-center experience involving intracapsular dissection for Shamblin II carotid body tumors (CBTs) and compares the outcomes with the classic technique of subadventitial resection. Based on the preliminary results, it seems that the enucleation technique facilitates the dissection of carotid body tumors, offering protection to cranial nerves and the internal/external/common carotid artery by utilizing the capsule as a barrier. The classic subadventitial resection approach and the enucleation technique have comparable postoperative complications. However, it is crucial to continue following the patients who underwent these resection techniques to determine the long-term outcomes. Moreover, the enucleation technique significantly reduces surgery duration and intraoperative blood loss.

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.

Preoperative Embolization in Surgical Resection of Cervical Paragangliomas: Usefulness and Current Evidence

BACKGROUND

Cervical paragangliomas (CPG) are slow-growing tumours, most of which are highly vascular, making surgical resection challenging. Preoperative embolisation of afferent arteries has been recommended to facilitate operative dissection, reduce perioperative blood loss, and shorten the duration of the operation. However, there is conflicting evidence on the benefits of preoperative embolisation on surgical outcomes, operative time, and bleeding.

OBJECTIVES

The objective of this study was to compare the perioperative parameters and outcomes like duration of surgery, blood transfusion, duration of stay in the ICU, cranial nerve injuries, and postoperative stroke between patients who underwent excision of CPGs with and without preoperative embolisation.

METHODS

This is a retrospective study conducted at the Division of Vascular Surgery, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. The study included a review of the medical records of 32 patients who underwent excision of CPGs. Patients who underwent surgical resection without preoperative embolisation (SR) were compared with those who underwent surgical resection with embolisation (SREMB). Statistical analysis was done in R statistical software (R Foundation for Statistical Computing, Vienna, Austria). Categorical variables were reported in absolute numbers and percentages continuous variables were compared with an unpaired Mann-Whitney U test. The chi-square test was used to compare the categorical data.

RESULTS

Out of 32 patients included in this study, 13 (40.6%) patients were included in the SREMB group. Between the two groups, there were no significant differences in operative time (120 vs. 150 minutes; p = 0.59), blood transfusion requirement (0.69 vs. 0.37 units; p = 0.39) and ICU stays (1 vs. 1; p = 0.56). Postoperative cranial nerve injury was significantly more in the SREMB group (6 vs 1; p = 0.01) but stroke (0 vs 2; p = 0.50) was not statistically significant between the two groups.

CONCLUSION

In this study, we found that there was insufficient evidence to support routine preoperative embolisation in CPG. Hence, preoperative embolisation should only be used in a very select group of patients.

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.

Safe management of carotid body tumor resection without preoperative embolization: an Ecuadorian high-altitude cities experience

Carotid body tumors (CBTs) are a neoplasm that affects the carotid glomus. This study aims to improve the management of CBTs in Ecuador. This single-center, retrospective observational study was conducted at the Instituto de la Tiroides y Enfermedades de Cabeza y Cuello (ITECC). We included adults with CBTs, between January 2019 and August 2022. A total of 15 patients with CBTs were included. All patients were females living at high altitudes (>2500 m). In the Shamblin classification, 12 tumors were type II, and 3 were type III. Complete tumor resection was performed in all patients without pre-operative embolization. All patients had benign CBTs with a mean follow-up of 17, 73 months. In a time when the medical cost is high mainly in low-income countries such as Ecuador, further investigation should be undertaken in the form of randomized prospective trials to answer who would benefit from the pre-TAE procedure.

Non-Functional Carotid Body Tumors in Patients Without Somatic Mutations May Be Considered for Non-Operative Management

BACKGROUND

Carotid Body Tumors (CBT) are rare neuroendocrine paragangliomas which are typically asymptomatic and benign, with a low rate of biochemical functionality. Historically, early surgical excision was recommended to prevent development of CBT-related complications. Yet, CBT resection can result in significant cranial nerve and vascular injuries. Recent work has shown successful primary observation without resection of non-carotid body, cranial paragangliomas with slow growth and low rate of neuropathies. We hypothesize that primary observation of CBT is safe and may be considered for majority of CBT.

METHODS

Retrospective cohort study of patients at a multi-hospital healthcare system with radiologic identification and/or diagnostic or procedural billing codes for CBT (2000-2019). Tumor size (greatest diameter), associated symptoms, and interventions were recorded at the initial evaluation and throughout follow-up. Multivariable logistic regression investigated the risk of initial surgical resection.

RESULTS

A total of 108 patients (mean age, 59 ± 19 years; 67% female), with 123 CBT (mean diameter 23 ± 12 mm; 52% right) were initially evaluated by otolaryngologists (51%), vascular surgeons (25%), neurosurgeons (8%), or other (16%) medical providers. Fity-five CBT were initially resected, 63 observed, and 5 irradiated. Initial resection was associated with younger age (adjusted odd ratios aOR, 0.95 [95% confidence intervals CI, 0.92-0.97]), male sex (aOR, 4.82 [95% CI, 1.47-15.75]), and evaluation by a vascular surgeon (aOR, 6.17 [95% CI, 2.04-18.63]). Overall median follow-up was 4.7 (IQR, 2.6-9.1) years. Initially observed CBT were on an average stable in size (mean 1 ± 5 mm/year), none became biochemically active, and 2 patients became symptomatic. At the final follow-up, 63 (51%) underwent surgical resection, 54 (44%) observation, and 6 (5%) radiation therapy. Of the 63 surgically resected CBT, 5 (8%) patients had malignant CBT of which 3 (60%) had known somatic mutations (polymerase epsilon [n = 1], succinate dehydrogenase-D gene [n = 2]). Thirty percent of CBT resections had in-hospital postoperative complications, notably including 1 stroke which occurred in an initially observed patient and 16 cranial nerve complications which all occurred in immediately resected patients. Three resected CBT locally recurred, only 1 of which had malignant pathology.

CONCLUSIONS

Patients with newly diagnosed CBT require biochemical functionality and somatic mutation testing. In the absence of these findings, initial observation of CBTs with annual imaging and symptom monitoring may be considered an alternative to immediate resection which demonstrates a high risk of clinically meaningful postoperative complications.

Beneficial effects of preoperative superselective embolization on carotid body tumor surgery: A 13-year single-center experience

Purpose

This study presented our 13-year experience managing patients with CBTs (carotid body tumors) and was aimed to investigate the impact of pre-TAE (preoperative transarterial embolization) on CBT surgical resection.

Methods

This retrospective study reviewed 169 surgically excised CBTs between May 2007 and October 2020. According to whether to carry out the pre-TAE, the patients were classified into the embolization (EG) (n = 130) and non-embolization groups (NEG) (n = 39). Tumor classification was based on Shamblin criteria and tumor size. The demographic data, clinical features, and intraoperative and postoperative information about the patients were retrieved and analyzed.

Results

The average tumor size was (43.49 vs. 35.44 mm, p = 0.04) for EG and NEG. The mean surgical time (195.48 vs. 205.64 mins, p = 0.62) and intraoperative BL (blood loss) (215.15 vs. 251.41 cc, p = 0.59) were less, but the incidence of revascularization required (29% vs. 33%, p = 0.62) and total complications (26% vs. 36%, p = 0.32) were lower in EG compared to NEG. Similarly, according to the subgroup analysis, no significant differences were detected in the surgical time, BL, adverse events (AEs), and the revascularization in EG when compared to NEG for type I (n = 5 vs. 7), II (n = 105 vs. 27), and III (n = 20 vs. 5), respectively except for the surgical duration in type III (p &lt; 0.05). However, a significantly lower incidence of AEs (230.25 vs. 350 cc, p = 0.038) and a decline in BL (28.57% vs. 48.15%, p = 0.049) in EG were observed compared to those in NEG patients for large CBTs (≥ 30 mm as the cutoff point). No surgery-related mortality was observed during the follow-up.

Conclusions

CBTs can be surgically resected safely and effectively with a need for pre-TAE, which significantly decreases the overall BL and AEs for large lesions (≥ 30 mm).

Current trends in carotid body tumors: Comprehensive review

BACKGROUND

Carotid body tumor (CBT) is a rare neoplasm that has been increasingly studied during the last decades; nevertheless, it continues to be a topic of controversy. This review aims to provide an update on the general features of CBT and particularly review different treatment strategies and primary outcomes.

METHODS

Data for this literature review were identified by PubMed, Scopus, and Medline. 93 articles from the initial search were included, as well as 28 relevant studies utilizing the snowballing method; totaling 121 articles about CBT.

RESULTS

Main features such as anatomy, embryology, genetics, clinical presentation, and diagnosis of CBT are presented, followed by evidence of different treatment strategies such as radiotherapy, preoperative embolization, vascular resection, and vascular reconstruction. Main complications are also discussed.

CONCLUSION

This review summarizes the most critical aspects regarding CBT. Future studies should compare different treatments to attain the best surgical results with lower morbidity rates.

Impact of Preoperative Embolization on Carotid Body Tumor Surgery

OBJECTIVES

In this study, investigation of the effect of preoperative carotid body tumor embolization (CBTE) on the amount of bleeding, vascular and neurological complications in carotid body tumors was aimed.

METHODS

50 patients treated for 51 carotid body tumors in 2 clinics, between 2005 and 2020 were evaluated. Polyvinyl alcohol (PVA) embolization of the carotid body tumor was performed in 23 patients before the surgical excision. The results were compared with the remaining 28 patients, whom CBTE was not performed, in terms of neurological complications, requirement of additional vascular interventions, bleeding amount, and length of hospital stay.

RESULTS

Mean bleeding amount was significantly lower in CBTE group (406ml-217ml p<0.05). Median erythrocyte suspension (ES) transfusion was significantly lower in the CBTE group (0.3 units vs. 1.1 units, p<0.05). Neurological deficits developed in a total of 13 patients, 6 of whom were in the CBTE group and 7 in the non-CBTE group, in the early postoperative period (p=0.90). No significant difference was observed between the groups in terms of additional vascular interventions and length of hospital stay (p=0.79 and p=0.61).

CONCLUSIONS

Carotid body tumors are rarely encountered tumors. However, their surgical excision is challenging for surgeons regarding intraoperative and postoperative bleeding. This study demonstrates that preoperative CBTE significantly reduces the amount of bleeding, especially in Shamblin II/III tumors.

A rare case of carotid body tumor associated with near complete cerebral sinus thrombosis and idiopathic intracranial hypertension. Management strategy and review of the literature

Background

Carotid body tumors (CBTs) are rare hypervascular lesions with critical location which makes them very challenging to treat. In rare occasions, compression of the jugular vein from the tumor mass could predispose to progressive thrombosis of intracranial venous sinuses. The latter consequently leads to intracranial hypertension (pseudotumor cerebri) with the accompanying danger to the vision. Herewith, we present our management strategy for this rare presentation of CBTs.

Case Description

A 38-year-old woman, with no medical history, was admitted in the emergency unit with acute onset of headache, dizziness, and vomiting. On the diagnostic imaging studies (CT venography and MRI) a near total occlusion of all cerebral venous sinuses and a large CBT (Shambin Type II) were diagnosed. Initially, the patient was treated with anticoagulants for the thrombosis and with lumbo-peritoneal (LP) shunt for the management of pseudotumor cerebri. At a second stage, after resolution of the cerebral sinus thrombosis, the CBT was completely resected under electrophysiological monitoring, without preoperative embolization. At 1-year follow-up, the patient is neurologically intact with functioning LP shunt, patent cerebral venous sinuses, without tumor recurrence.

Conclusion

We present a rare case of CBT with intracranial complications, which was managed successfully by staged treatment. Careful study of the preoperative radiological and laboratory data, thorough preoperative planning of the tridimensional lesion anatomy, as well as meticulous microsurgical technique under intraoperative electrophysiological monitoring was essential for the successful outcome of the case.