The impacts of different embolization techniques on splenic artery embolization for blunt splenic injury: a systematic review and meta-analysis.

BACKGROUND: Splenic artery embolization (SAE) has been an effective adjunct to the Non-operative management (NOM) for blunt splenic injury (BSI). However, the optimal embolization techniques are still inconclusive. To further understand the roles of different embolization locations and embolic materials in SAE, we conducted this system review and meta-analyses. METHODS: Clinical studies related to SAE for adult patients were researched in electronic databases, included PubMed, Embase, ScienceDirect and Google Scholar Search (between October 1991 and March 2013), and relevant information was extracted. To eliminate the heterogeneity, a sensitivity analysis was conducted on two reduced study sets. Then, the pooled outcomes were compared and the quality assessments were performed using Newcastle-Ottawa Scale (NOS). The SAE success rate, incidences of life-threatening complications of different embolization techniques were compared by χ2 test in 1st study set. Associations between different embolization techniques and clinical outcomes were evaluated by fixed-effects model in 2nd study set. RESULTS: Twenty-three studies were included in 1st study set. And then, 13 of them were excluded, because lack of the necessary details of SAE. The remaining 10 studies comprised 2nd study set, and quality assessments were performed using NOS. In 1st set, the primary success rate is 90.1% and the incidence of life-threatening complications is 20.4%, though the cases which required surgical intervention are very few (6.4%). For different embolization locations, there was no obvious association between primary success rate and embolization location in both 1st and 2nd study sets (P > 0.05). But in 2nd study set, it indicated that proximal embolization reduced severe complications and complications needed surgical management. As for the embolic materials, the success rate between coil and gelfoam is not significant. However, coil is associated with a lower risk of life-threatening complications, as well as less complications requiring surgical management. CONCLUSIONS: Different embolization techniques affect the clinical outcomes of SAE. The proximal embolization is the best option due to the less life-threatening complications. For commonly embolic material, coil is superior to gelfoam for fewer severe complications and less further surgery management.

Thrombin-loaded alginate-calcium microspheres: A novel hemostatic embolic material for transcatheter arterial embolization.

Transcatheter arterial embolization (TAE) is the best non-laparotomy choice for solid visceral organs rupture and bleeding nowadays. In our previous study, a new biodegradable macromolecule material thrombin-loaded alginate-calcium microsphere (TACM) was prepared and its characteristics were investigated preliminarily. In this study, we further investigated the biocompatibility of TACMs, as well as physical characteristic, application method and effect of TACMs with thrombus (embolic agent). The in vivo results attested that TACMs were non-irritating and non-genotoxic with desired biocompatibility, although brought about a slight and temporary inflammation. Application research showed that the function of thrombin was inhibited by common contrast agents, and it was impracticable to add contrast agents in TACMs with thrombus for tracing under X-rays in TAE. Then, a novel delivery method was developed. In addition, stress resistance test indicated that the TACMs with thrombus was significantly stronger than single autologous thrombus, the optimized ratio of TACMs to whole blood was 2:3 for forming mixed thrombus. Finally, large animal experiment revealed that the novel embolic agent - TACMs mixed thrombus was effective and safe in treating hemorrhage of solid abdominal viscera by TAE.

Alginate-calcium microsphere loaded with thrombin: a new composite biomaterial for hemostatic embolization.

To date, transcatheter arterial embolization (TAE) has become a standard treatment to control intracavitary bleeding as an alternative to surgery. Due to excellent biocompatibility and no residual in vivo, biodegradable materials are preferred in TAE. However, gelfoam is the only commercially available biodegradable embolic material used to treat blunt trauma of solid abdominal viscera until now, and controversial on its stability and reliability never stopped in the past five decades. In this study, a new biodegradable macromolecule material (thrombin-loaded alginate-calcium microspheres, TACMs) was prepared using electrostatic droplet techniques and a special method was developed for hemostatic embolization. Thrombin was successfully loaded into microspheres with high encapsulation efficiency and drug loading capacity. A burst release of TACMs was observed at early stage and sustained release later on, with the activity of thrombin preserved well. The strength of TACMs mixed thrombus, which was used as embolic agent, increased in a dose-dependent manner after TACMs were added. In addition, the TACMs were verified to be of no cytotoxicity and systemic toxicity, and biodegradable in vivo. Finally, the results of preliminary applications revealed that the TACMs could serve as an effective and promising embolic material for blunt trauma and hemorrhage of solid abdominal viscera.