Adam H. Power, Thomas C. Bower, Terri J. Vrtiska, Audra A. Duncan, Manju Kalra, Gustavo S. Oderich, Peter Gloviczki
Vascular and Endovascular Surgery, Mayo Clinic, Rochester, MN.
OBJECTIVES: Cranial nerve injury (CNI) remains an important complication of carotid body tumor (CBT) resection. The Shamblin classification has been used to predict CNI but it is subjective. Our objective was to determine imaging criteria for predicting CNI during CBT resections.
METHODS: Retrospective review of all consecutive patients surgically treated for CBTs at our institution from 2000 to 2010. Outcomes were compared between patients with CNI and those without it (NCNI group). A vascular radiologist reviewed all CT and MR scans from which tumor dimensions, volumes, and extent relative to the vertebral bodies and angle of the jaw were calculated.
RESULTS: Fifty-six patients with 61 CBT resections were reviewed. Of these, 47 patients (52 CBT resections) had CT or MR angiography available for review. Seventeen patients (20 CBT resections) sustained a CNI and 30 (32 CBT resections) did not (NCNI). Fifteen nerve injuries were temporary and 5 were permanent. Age, gender, family history, number of SDH(x) mutations, and bilateral CBT were similar between the groups. The number of patients treated by excision only, those who needed carotid artery reconstruction, operative time, and blood loss were similar between the two groups. Those patients who underwent pre-operative embolization had more CNI (75% vs. 44%, p=0.04). The CT or MR predictors for any cranial nerve injury were superior extent of the CBT in relation to the vertebral bodies (C1 vs. C2, p=0.001) and lateral margin of the CBT from the angle of the jaw (5 mm vs. 10 mm, p=0.04). CBT volume, percent encasement of the CBT around the carotid artery, shape (lobulated vs. ovoid), inferior extent of the CBT, and homogeneity were not significantly different between the groups.
CONCLUSIONS: CBTs with a superior extent to the C1 vertebral level or with a lateral margin less than 5mm from the angle of the jaw on CT or MR are at risk for cranial nerve injury during resection.
AUTHOR DISCLOSURES: T. C. Bower, Nothing to disclose; A. A. Duncan, Nothing to disclose; P. Gloviczki, Nothing to disclose; M. Kalra, Nothing to disclose; G. S. Oderich, Nothing to disclose; A. H. Power, Nothing to disclose; T. J. Vrtiska, Nothing to disclose.
Posted April 2012