Postembolization CT Digital Subtraction Angiography for Assessing Spinal Tumor Devascularization: Concordance With Catheter Angiography and Association With Surgical Blood Loss.

Background

Context

The adequacy of preoperative embolization for spinal tumors is commonly assessed using selective catheter angiography, but standardized criteria remain lacking. Postembolization CT digital subtraction angiography (CT-DSA) may provide complementary whole-tumor assessment of residual enhancement.

Purpose

To evaluate concordance between postembolization CT-DSA and catheter angiography, examine associations between CT-DSA findings and surgical blood loss, and identify factors associated with less favorable CT-DSA findings.

Design

Retrospective single-center observational cohort study. PATIENT SAMPLE Seventy-two adults who underwent preoperative embolization and postembolization CT-DSA before spinal tumor surgery, including 62 patients with metastatic tumors and 10 with primary spinal neoplasms. OUTCOME MEASURES Concordance between CT-DSA and catheter angiographic devascularization categories, estimated blood loss (EBL), quantitative CT-DSA peak enhancement index, and factors associated with less favorable CT-DSA categories.

Methods

Postembolization devascularization was classified as complete, subtotal, or partial using modality-specific criteria. Concordance was evaluated using cross-classification and linearly weighted κ. Associations between CT-DSA findings and EBL were analyzed in patients with metastatic tumors using multivariable regression adjusted for surgical invasiveness and baseline angiographic hypervascularity. Proportional-odds ordinal regression was used to explore factors associated with less favorable CT-DSA categories.

Results

CT-DSA and catheter angiography assigned the same devascularization category in 39 of 72 patients (54.2%), with moderate weighted concordance (κ=0.423; 95% confidence interval [CI], 0.265-0.580). Among patients with metastatic tumors, median EBL was 1,000 mL for complete, 1,650 mL for subtotal, and 1,975 mL for partial devascularization (P=.214). The adjusted overall association between CT-DSA category and EBL was not statistically significant (P=.167). Compared with complete devascularization, partial devascularization showed a directionally higher but imprecise EBL estimate (adjusted EBL ratio, 1.582; 95% CI, 0.861-2.907; P=.139). The quantitative peak enhancement index was not associated with EBL. Greater baseline angiographic hypervascularity (adjusted odds ratio [OR] per grade, 3.243; 95% CI, 1.782-5.902) and a same-level spinal artery (adjusted OR, 10.236; 95% CI, 2.477-42.293) were associated with less favorable CT-DSA categories.

Conclusions

Postembolization CT-DSA showed moderate concordance with catheter angiography and may complement selective angiographic assessment by depicting residual enhancement throughout the tumor. Partial devascularization showed a directionally higher but imprecise association with surgical blood loss in metastatic tumors and requires further validation.