The effect of preoperative embolization on surgical outcomes for carotid body tumor resection

Abstract

Objective: Compare the effects of preoperative embolization for carotid body tumor resection on surgical outcomes to carotid body tumor resections without preoperative embolization.

Methods: Single-center retrospective review of all consecutive patients who underwent carotid body tumor resection from 2001 to 2019. Surgical outcomes with emphasis on operative time (estimated blood loss and cranial nerve injury) of patients undergoing carotid body tumor resection following preoperative embolization were compared to those undergoing resection alone using unpaired Student's t-test and Fisher's exact test.

Results: Forty-six patients (15% male, mean age 50 ± 15 years) underwent resection of 49 carotid body tumors. Patients undergoing preoperative embolization (n = 20 (40%)) had larger mean tumor size (4.0 ± 0.7 vs 3.2 ± 1 cm, p = 0.006), increased Shamblin II/III tumor classification (18 (90%) vs 22 (76%), p < 0.001), operative time (337 ± 195 vs 199 ± 100 min, p = 0.004), and cranial nerve injuries overall (8 (40%) vs 2 (10%), p = 0.01) compared to patients undergoing resection without preoperative embolization (n = 29 (60%)). In subgroup analysis of Shamblin II/III classification tumors (n = 40), preoperative embolization (n = 18) was associated with increased tumor size (4.1 ± 0.6 vs 3.5 ± 0.9 cm, p = 0.01), operative time (351 ± 191 vs 244 ± 105 min, p = 0.02), and cranial nerve injury overall (8 (44%) vs 2 (9%), p = 0.03) compared to resections alone (n = 19). In further subgroup analysis of large (⩾ 3 cm) tumors (n = 37), preoperative embolization (n = 18) was associated with increased operative time (350 ± 191 vs 198 ± 99 min, p = 0.006) and cranial nerve injury overall (8 (44%) vs 2 (11%), p = 0.03) compared to resections alone (n = 19). There were no significant differences in estimated blood loss, transfusion requirement, or hematoma formation between any of the embolization and non-embolization subgroups.

Conclusion: After controlling for tumor Shamblin classification and size, carotid body tumor resections following preoperative embolization were associated with increased operative time and inferior surgical outcomes compared to those tumors undergoing resection alone. Nonetheless, such results remain susceptible to the confounding effects of individual tumor characteristics often used in the decision to perform preoperative embolization, underscoring the need for prospective studies evaluating the utility of preoperative embolization for carotid body tumors.

Keywords: Carotid body tumor; Shamblin classification; cranial nerve injury; high-altitude; preoperative embolization.

Figure 1.

Shamblin classification: (a) Diagram of Shamblin classification of difficulty of CBT resection. Group 1 tumors are localized with minimal attachment to the carotid vessels. Group 2 tumors are generally larger with moderate arterial attachment. Group 3 tumors are also large and encase the carotid vessels, thus presenting the greatest operative challenge and (b) Examples of radiographic Shamblin classification of CBT. CBT: carotid body tumor; ICA: internal carotid artery; ECA: external carotid artery.