92 Clinical and Experimental Otorhinolaryngology Vol. 3, No. 2: 91-95, June 2010 CBTs by ligation of feeding branches of the external carotid artery (ECA) during operation has been a common practical technique. Recently, van der Bogt et al. (4) proposed a craniocaudal dissec- tion technique that would minimize postoperative morbidity. Although advances in surgical techniques and the introduction of sensitive imaging modalities have significantly reduced mortality, the incidence of perioperative neurovascular complications, espe- cially cranial nerve (CN) deficit and intraoperative hemorrhage, remains considerable (5, 6). Since Shamblin et al. proposed the classification of CBTs based on the involvement of carotid vessels in 1971, it has been widely used to describe the CBTs (7). Shamblin group I tumors are localized and do not involve the surrounding major vessels, group II are adherent or partially surround the vessels, and group III are large and encase the vessels. The size of tumor is posi- tively correlated with the Shamblin classification because CBTs become more adherent to carotid vessels as they become larg- er. However, clinical implications of Shamblin classification in perioperative complications or prognosis have not well docu- mented in the literature (8, 9). The purpose of this study was to review our experience in the surgical management of CBTs and evaluate the outcomes and complications according to the Shamblin classification. MATERIALS AND METHODS We included 15 CBTs of 13 patients who had been diagnosed and surgically treated at a single institute in this study. Patients consisted of 6 men and 7 women, and their age ranged from 34 to 61 yr (median, 44 yr). The medical records of each patient were reviewed for demographic details, radiologic findings, surgical outcomes, and follow up. Imaging studies included computed tomography (CT) and/or magnetic resonance (MR) imaging for the evaluation of tumor size and Shamblin group. Preoperative conventional angiogra- phy was performed in all patients and tumor embolization was accomplished if possible. Preoperative embolization was not rou- tinely performed when the feeding vessels of the tumor are very close to the internal carotid artery (ICA) with a high risk of embol- ic particle migration to ICA or if there are multiple anastomoses between carotid vessels and tumors, thus complicating identifica- tion of the feeding vessels. Tolerance to carotid balloon occlusion was also tested in all patients. Surgery was performed within 48 hr of embolization to avoid recruitment of collateral blood sup- ply and minimize inflammatory reaction in patients who were given preoperative embolization. The surgical procedures are briefly described as follows: CBTs were exposed through a transverse cervical incision. All neurovas- cular structures were identified and periadventitial dissections of the carotid artery were performed. Proximal and distal control of the ICA, ECA, and common carotid artery (CCA) were per- formed before tumor resection. Any feeding vessels supplying the tumor were ligated early, and the ECA was selectively ligat- ed for complete tumor resection. When a portion of the carotid artery had to be resected, vascular surgeons performed carotid artery reconstruction using an autologous saphenous vein or prosthetic vascular graft (Hemashield, Woven Double Velour, Boston Scientific Corp., Wayne, NJ, USA). The follow up period ranged from 15 to 64 months with a medi- an follow up of 29 months. SPSS ver. 12.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Differences between the two groups were analyzed by Mann-Whitney test. Significance was defined as a P-value less than 0.05. RESULTS Fifteen CBTs were found in 13 patients and 13 tumors were resect- ed. Four tumors (31%) were located in the right and seven (54%) A B C Fig. 1. A 35-yr-old woman with a characteristic carotid body paraganglioma. (A) Axial contrast-enhanced CT shows an avidly enhancing mass splaying the external carotid artery (ECA) and internal carotid artery (ICA) at the left carotid bifurcation. (B) Axial T1- weighted images show a mass with prominent vascular flow voids. (C) Angiography shows intense tumor blush between the ICA and ECA.