From the Guidelines
Endovascular embolization of a carotid body tumor involves preoperative angiography with embolization, which is recommended for all large (>4 cm) or locally invasive carotid/vagal PGLs, to help achieve a dry surgical field and reduce surgical morbidity. This approach is supported by the clinical consensus guideline on the management of phaeochromocytoma and paraganglioma in patients harbouring germline sdhd pathogenic variants, published in The Lancet Diabetes and Endocrinology in 2023 1. The procedure typically begins with femoral artery access and angiography to identify the tumor's vascular supply, which commonly arises from branches of the external carotid artery.
Key considerations for the embolization procedure include:
- Selective catheterization of the feeding vessels
- Delivery of embolic agents to devascularize the tumor
- Avoiding reflux of embolic material into the internal carotid artery to prevent stroke
- Use of embolic materials such as polyvinyl alcohol particles, microspheres, or liquid embolic agents like Onyx or n-butyl cyanoacrylate (NBCA)
- Performance of embolization 24-72 hours before surgical resection to reduce intraoperative bleeding and avoid inflammatory changes
The goal of preoperative embolization is to minimize morbidity and increase the probability of gross total resection, as stated in the guideline 1. It is essential to weigh the benefits of embolization against the potential risks, including temporary or permanent cranial neuropathy, and to involve a multidisciplinary team in the decision-making process.
Important factors to consider when deciding on the therapeutic strategy for carotid body tumors include:
- Patient's life expectancy
- Tumor behavior
- Baseline neurological/cranial nerve status
- Swallowing function
- Pulmonary reserve
- The possibility of future metachronous lesions, as mentioned in the guideline 1.
By prioritizing these factors and using a personalized approach, clinicians can optimize treatment outcomes and minimize the risk of complications for patients with carotid body tumors.
From the Research
Carotid Body Tumor Embolization
- Carotid body tumors (CBTs) are highly vascularized lesions that require successful preoperative embolization to achieve favorable clinical results in terms of morbidity and complete tumor resection 2.
- Preoperative embolization has been used to decrease tumor volume, intraoperative blood loss, and nerve injuries 3, 4, 5.
- The procedure of percutaneous embolization can be performed using various materials such as ethylene-vinyl alcohol copolymer (Onyx), polyvinyl alcohol, and N-butyl cyanoacrylate glue 2, 6.
- Embolization can be performed via an endovascular approach, with the goal of reducing tumor blush and facilitating surgical resection 3, 6.
Endovascular Approach
- The endovascular approach involves the use of angiography to identify the feeding arterial vessels, followed by embolization using a suitable material 3, 6.
- The procedure can be performed by interventional neuroradiologists, and the results can be evaluated by assessing the reduction in tumor blush and the ease of surgical resection 6.
- The average reduction in tumor blush following embolization can be significant, ranging from 40% to 95% 6.
Benefits and Complications
- Preoperative embolization can decrease blood loss and shorten operation time, resulting in lower postoperative neurologic morbidity 5.
- However, the role of preoperative embolization in CBT has been questioned, and some studies have found no benefits supporting embolization prior to surgery 4.
- The complications of embolization can include cranial nerve dysfunction, and the risk of embolization procedural complications should be carefully evaluated 5, 6.