Role of Preoperative Embolization in Surgical Treatment of the Carotid Body Paragangliomas:

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.

Use of the Amplatzer vascular plug to treat carotid body tumors extending to the skull base

BACKGROUND

Carotid body tumors extending to the skull base are hypervascular tumors which are difficult to access using a traditional lateral cervical approach. Preoperative embolization can reduce intraoperative blood loss.

CASE PRESENTATION

We report two patients with a carotid body tumor extending to the skull base who underwent preoperative embolization of the external carotid artery using an Amplatzer vascular plug. Two days after embolization, surgical resection was performed. Embolization was successful in both patients and resection proceeded smoothly. Both were discharged on postoperative day 9 without complications. The tumor in each patient was classified as Shamblin group III. Computed tomography angiography of the neck six months after surgery showed patency of the ipsilateral internal carotid artery and no tumor recurrence.

CONCLUSION

Preoperative embolization of the external carotid artery using the Amplatzer vascular plug is safe and feasible for patients with carotid body tumors extending to the skull base.

Carotid paragangliomas. Alternatives for presurgical endovascular management

Carotid paragangliomas (CP) are rare tumors, representing 0.6% of the head and neck tumors. These tumors have their origin in the carotid body located in the adventitia of the vascular wall of the carotid bifurcation. Among their principal characteristics are hypervascularity, primarily dependent on branches of the external carotid artery, the proximity and possible involvement of the cranial nerves IX, X, XI, XII, and extension to the base of the skull. Complete surgical resection is the first line of management; however, this procedure can be a surgical challenge due to the potential risk of bleeding, intraoperative neurovascular injuries, and prolonged surgical time. Tumor embolization, carotid stenting, and tumor embolization with carotid stenting have been developed as alternative presurgical endovascular techniques that decrease tumor vascularity and/or provide structural vascular support, reducing bleeding and facilitating tumor dissection. Two cases of carotid tumors of the same classification, Shamblin II, are presented, one treated by preoperative embolization and the other managed with a carotid stent; the indications, advantages, and possible complications of each one are discussed. Two cases of Shamblin II carotid tumors are presented, one treated preoperatively with a carotid stent and the other with preoperative embolization. A literature review was carried out, with a search in PubMed that includes case reports, case series, review articles, meta-analyses on CP, presurgical tumor embolization, presurgical carotid stent placement, and surgical treatment of carotid body tumor. Hypervascularity and adhesion to the carotid wall are the leading causes of difficulties in surgical resection of CP. Optimal tumor embolization and/or preoperative carotid stent placement reduce intraoperative bleeding and provide vascular structural support, reducing intraoperative and postoperative complications.

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.

Is Preoperative Embolization Necessary for Carotid Paraganglioma Resection: Experience of a Tertiary Center

PURPOSE

This study was designed to investigate whether preoperative embolization is a useful procedure to decrease blood loss and neurovascular complications for carotid body tumor (CBT) surgery or not.

METHODS

Medical records of our tertiary care center from 2012 to 2019 were scanned for patients who underwent surgery for CBT, retrospectively. Age, gender, complaint and head and neck examination findings at the time of presentation, preoperative complete blood count parameters, imaging records (cervical magnetic resonance imaging and carotid artery angiography), Shamblin classification, tumor size, intraoperative findings, and postoperative complications were noted.

RESULTS

A total of 26 patients were operated due to CBT between 2012 and 2019 in our clinic; preoperative arterial embolization was performed to 15 (57.7%) patients, and 11 (42.3%) patients were operated without embolization. Youngest patient was 24 years old, while oldest was 69 years and mean age was 44.35 ± 12.73. (embolization group: ages ranging between 24 and 64 with a mean of 41.5 ± 11.02 years; in nonembolization group: ages ranging between 26 and 69 with a mean of 48.1 ± 14.3). Embolization status was not significantly related to cranial nerve injury, vascular injury, overall complications, and hematocrit decrease. Arterial injury is more likely to occur with increasing Shamblin class (r = .39; P = .04). Tumor size is not found to be significantly related to cranial nerve injury, vascular injury, overall complications, and hematocrit decrease, but cranial nerve injury and vascular injury were more likely to occur in large tumors (r = .34; P = .089 and r = .34; P = .087, respectively). Age was significantly and negatively correlated to vascular injury (r = -.51; P = .05). Vascular injury was significantly correlated with gender (male predominance: r = -.64; P = .000).

CONCLUSION

Although preoperative arterial embolization is considered to attenuate the complication risk, we found that there was no significant difference among the patients with or without embolization.