[Preoperative mixed embolization of a paraganglioma using Onyx]

Paragangliomas of the carotid body: current management protocols and review of literature

Paraganglioma is a rare neoplasm arising from carotid body usually benign and constitute 0.5 % of all total body tumors. They constitute 60-70 % of head and neck paraganglioma and resemble other paragangliomas of the body like glomus jugulare, glomus tympanicum, and pheochromocytoma. This is a retrospective analysis of the medical records of carotid body paraganglioma cases. Nine patients operated during the study period and the follow up traced were included in the study. Seven females and 2 males were analysed. Six had tumor on the left side and 3 had on the right side. All the cases surgical excision was done by a tranverse incision as 2 patients had Shamblin I, 5 patients had Shamblin II, and 1 patients Shamblin IIIa. All the Shamblin I had tumor away from the carotids and were easily dissected without vessel damage, a sub adventitial tumor excision was performed in all the 5 cases of Shamblin II, 1 case of Shamblin IIIa was dissected with difficulty without sacrificing or vessel reconstruction. Paraganglioma of the carotid body should be considered as a differential diagnosis for painless lateral neck masses. Larger tumors need a multidisciplinary team of head and neck with vascular surgeons for better results.

Safety and efficacy of vascular tumor embolization using Onyx: is angiographic devascularization sufficient?

OBJECT

The authors assessed the safety and efficacy of embolization of head, neck, and spinal tumors with Onyx and determined the correlation between tumor embolization and intraoperative blood loss.

METHODS

The authors prospectively collected all head, neck, and spinal tumors embolized with Onyx at their institution over a 28-month period. Information on tumor type, location, extent of tumor devascularization, endovascular and surgical complications, and intraoperative estimated blood loss (EBL) was evaluated.

RESULTS

Forty-three patients with various head, neck, and spinal lesions underwent vascular tumor embolization with Onyx. Indications for embolization included uncontrolled tumor bleeding in 8 cases, elective preoperative devascularization in 34, and tumor-induced consumptive thrombocytopenia in 1 case. Embolization was performed via direct tumoral puncture in 14 cases and through the traditional transarterial route in the remaining lesions. Embolization was successful in ending uncontrolled tumor bleeding in all 8 cases and in reversing the consumptive coagulopathy in 1 case. Intraparenchymal penetration of embolic material was possible in all percutaneously embolized tumors and in 4 of the 20 tumors embolized preoperatively via the transarterial route. The mean percentage of devascularization in tumors with intraparenchymal penetration of Onyx was 90.3% compared with 83.7% in tumors without intraparenchymal penetration. The mean EBL with intraparenchymal penetration of Onyx was significantly lower than when there was no intraparenchymal penetration (459 vs 2698 ml; p = 0.0067). There were no neurological complications related to the embolization procedures.

CONCLUSIONS

Embolization of vascular tumors with Onyx can be performed safely but may not reach optimal effectiveness in reducing intraoperative EBL if the embolic material does not penetrate the tumor vasculature. In the authors' experience, the best method of intraparenchymal penetration is achieved with direct tumor puncture. Transarterial embolization may not result in tumor penetration, particularly when injected from a long distance through small caliber or slow flow vessels.

Percutaneous embolization of carotid paragangliomas using solely Onyx

BACKGROUND AND PURPOSE

Paragangliomas are highly vascularized usually benign neoplasms arising from nerve tissue. Endovascular preoperative embolization is used to facilitate surgery but is often not complete, due to tiny feeding arteries not feasible for selective catheterization. Our purpose was to evaluate angiographic and clinical outcome using Onyx for percutaneous glomus tumor embolization.

MATERIALS AND METHODS

A consecutive series of 4 patients with 6 paragangliomas located at the bifurcation of the common carotid artery were treated with percutaneous embolization using Onyx as the sole embolic material.

RESULTS

Complete devascularization of the 6 paragangliomas was achieved using a percutaneous embolization technique with Onyx as a sole agent, combined with an endovascular microballoon that offered protection of the internal carotid artery.

CONCLUSIONS

Further documentation is necessary to prove the higher grade of devascularization of paragangliomas with Onyx compared with other embolic material and the associated potential to facilitate surgery. Nevertheless, Onyx seems to be safe when used percutaneously due to its lavalike pattern flow and its controllable properties, allowing slow tumor bed penetration.