Pre-operative embolisation of spinal tumours: neither neglect the neighbour nor blindly follow the gold standard

Abstract

A large variety of vertebral tumours undergoes transarterial embolisation (TAE) prior to surgery. However, the subsequent intra-operative blood loss is unpredictable. This retrospective analysis, aims to determine the impact of various factors that may potentially influence the estimated intra-operative blood loss (EBL) in these patients. The study included 56 consecutive patients with spinal tumours who underwent pre-operative TAE. Demographic information, treatment history, tumour type, MRI characteristics, angiographic appearance, embolisation technique and surgical invasiveness were correlated with EBL using univariate and multivariate analysis. Mean EBL was 1317 mls. On univariate analysis, haematological/primary tumours, MRI hypervascularity and selective embolisation were significantly (P < 0.05) associated with increased EBL. A total angiographic devascularisation and embolisation of additional segments above and/or below the involved level were significantly associated with decreased EBL. There was no significant association with hypervascular angiographic appearance or surgical invasiveness. MRI and angiographic hypervascularity were not entirely concordant, especially for the category of moderately vascularised metastases. After multivariate analysis, MRI hypervascularity (1434 vs. 929 mls, P = 0.018) and embolisation of additional segments (1082 vs. 1607 mls, P = 0.003) remained significantly correlated with EBL. In conclusion, during pre-operative TAE of spinal tumours, routine angiographic interrogation of additional levels above and below the involved segment should be made, with a low threshold for embolising them, if safely performable. Compared to angiographic gold standard, MRI hypervascularity is probably a better predictor of EBL.

Keywords: Angiography for vertebral metastasis; Intra-operative blood loss; MRI of vertebral metastasis; Spinal tumour; Transarterial embolisation of spinal tumours.