Only Tumors Angiographically Identified as Hypervascular Exhibit Lower Intraoperative Blood Loss Upon Selective Preoperative Embolization of Spinal Metastases: Systematic Review and Meta-Analysis

Abstract

BackgroundThe role of preoperative embolization (PE) in reducing intraoperative blood loss (IBL) during surgical treatment of spinal metastases remains controversial.MethodsA systematic search was conducted for retrospective studies and randomized controlled trials (RCTs) comparing the IBL between an embolization group (EG) and non-embolization group (NEG) for spinal metastases. IBL data of both groups were synthesized and analyzed for all tumor types, hypervascular tumor types, and non-hypervascular tumor types.ResultsIn total, 839 patients in 11 studies (one RCT and 10 retrospective studies) were included in the analysis. For all tumor types, the average IBL did not differ significantly between the EG and NEG in the RCT (P = 0.270), and there was no significant difference between the two groups in the retrospective studies (P = 0.05, standardized mean difference [SMD] = −0.51, 95% confidence interval [CI]: −1.03 to 0.00). For hypervascular tumors determined as such by consensus (n = 542), there was no significant difference between the two groups (P = 0.52, SMD = −0.25, 95% CI: −1.01 to 0.52). For those determined as such using angiographic evidence, the IBL was significantly lower in the EG than in the NEG group, in the RCT (P = 0.041) and in the retrospective studies (P = 0.004, SMD = −0.93, 95% CI: −1.55 to −.30). For IBL of non-hypervascular tumor types, both the retrospective study (P = 0.215) and RCT (P = 0.947) demonstrated no statistically significant differences in IBL between the groups.ConclusionsOnly tumors angiographically identified as hypervascular exhibited lower IBL upon PE in this study. Further exploration of non-invasive methods to identify the vascularity of tumors is warranted.

Preoperative embolization of hypervascular spinal tumors: Two case reports

“…[ 4 ] Several studies have indicated that patients who undergo PE experience surgical and clinical benefits compared to patients who did not undergo PE. [ 2 , 11 - 13 ] Complete embolization can be achieved in 50-86% of patients. [ 4 ] Incomplete embolization can occur due to the presence of nearby radiculomedullary arteries, the inability to selectively catheterize feeding arteries, and intratumoral arteriovenous shunting.…”

“…[ 8 ] Studies have demonstrated that intraoperative blood loss in the embolization group is significantly reduced compared to the non-embolization group. [ 2 , 11 , 13 , 14 ]…”

“…[ 7 , 9 , 11 ] Reported complications include groin hematoma, cardiac event secondary to anesthesia, common femoral artery thrombosis, bleeding, and neurologic injuries, such as acute stroke, nerve root injury, and spinal cord ischemia. [ 2 , 7 , 12 , 14 ] Spinal cord infarction and the deterioration of neurological status are major complications associated with embolization. [ 2 ] Spinal cord infarction can occur secondary to the occlusion of the anterior or posterior spinal arteries, whereas acute stroke can occur due to the reflux of embolic material into the parent artery, followed by transport to the brain.…”

“…[ 2 , 7 , 12 , 14 ] Spinal cord infarction and the deterioration of neurological status are major complications associated with embolization. [ 2 ] Spinal cord infarction can occur secondary to the occlusion of the anterior or posterior spinal arteries, whereas acute stroke can occur due to the reflux of embolic material into the parent artery, followed by transport to the brain. [ 5 ] Neurologic injuries can also be caused by postembolization tumoral swelling, which may compress the spinal cord.…”

“…[ 1 ] Preoperative embolization (PE) is a useful adjunctive procedure for improving surgical outcomes and reducing complications in patients with hypervascular spinal tumors. [ 2 ] First reported by Benati et al ., [ 3 ] PE not only reduces intraoperative blood loss and facilitates complete tumor resection but also reduces the mass effect and relieves spinal cord compression. [ 4 ] We report two cases that highlight how patients with hypervascular tumors can benefit from PE.…”