Spinal metastases from renal cell carcinoma: effect of preoperative particle embolization on intraoperative blood loss

Abstract

Background and purpose: Surgical repair of spinal metastases from renal origin is often complicated by excessive bleeding. The purpose of this study was to assess the effect of preoperative particulate embolization on intraoperative blood loss.

Methods: Twenty spinal metastases from renal origin (17 patients) treated by preoperative embolization with polyvinyl alcohol particles were analyzed retrospectively. Surgical decompression was performed within 2 days after embolization. A control group of 10 patients with 11 spinal metastases of renal origin underwent surgery without embolization. The effect of preoperative embolization, of completeness of embolization, and of particle size on the estimated intraoperative blood loss was analyzed using nonparametric statistical tests.

Results: Complete embolization was achieved in 10 cases and partial embolization in the other 10. The estimated blood loss of 19 embolized and 11 control cases was available from the surgical report. Median intraoperative blood loss in 19 embolized lesions was 1500 mL (range, 300-8000 mL), compared with 5000 mL (range, 1440-15000 mL) in the control group. Even after partial embolization, blood loss (median, 2000 mL) was significantly lower than in the control group. No significant differences in estimated blood loss were noted between the use of particles smaller than 250 microm and those larger than 250 microm. No embolization-related permanent neurologic deficit or skin or muscle necrosis occurred.

Conclusion: Preoperative embolization of spinal metastases of renal origin with polyvinyl alcohol particles is safe and might reduce intraoperative blood loss significantly. Even partial embolization seems to be effective.

fig 1.

A, CT scan in a patient with metastasis involving the T7 vertebral body (asterisk). B, Selective angiogram of the right 7th intercostal artery with a 5F Cobra-shaped catheter shows a hypervascular mass (arrows) and no arterial supply to the spinal cord. C, Injection after further selective catheterization with a 3F Tracker catheter (solid arrow indicates catheter tip), protective embolization of intercostal artery distal to the tumor feeders with a platinum coil (open arrow), and embolization with PVA particles. No tumor blush is identified. A coil (arrowhead) is seen in the 6th right intercostal artery after previous embolization

fig 2.

A, T1-weighted axial MR image shows a large metastasis (asterisk) involving the C2 vertebral body and extending into the surrounding soft tissues. B, Early arterial phase of a preembolization right vertebral angiogram shows a hypervascular mass (arrowheads) supplied by small cervical branches of the vertebral artery. C, Right vertebral angiogram obtained after balloon occlusion of the vertebral artery at the level of C1 (arrow) and embolization with PVA particles. No residual tumor stain is visible