摘要
目的 筛选可作为超声可视化肝内定位标记物的材料,分析其指导超声引导下射频消融肝肿瘤的效果.方法 本实验纳入24种医用材料作为标记物,包括1种气体、18种液体、5种固体材料.体外实验采用超声引导下于离体牛肝内植入可视化定位标记物,评估其超声可视性及持久性;分别以消融电极针距标记物垂直距离1.0 cm、0.5 cm及电极针紧贴标记物进行局部消融,分析射频热场对标记物的影响.动物实验采用超声引导下于活体比格犬肝内植入可视化定位标记物,评估其超声可视性及持久性;消融后观察实验犬并发症发生情况,于消融第7天复查超声观察犬肝内标记物情况,通过消融区组织标本观察标记物位置及肝组织损伤情况.结果 体外实验显示,空气、吸收性明胶海绵、聚乙醇酸(PGA)可吸收手术缝线、5mm金属、声诺维-F127、海藻酸钙、超声耦合剂、聚桂醇的超声可视性及持久性均较好.消融电极针距标记物垂距离1.0 cm、0.5 cm处进行消融后,上述标记物在二维超声图像中均可清晰显示,未受消融热场影响;消融电极针紧贴标记物进行消融后,仅5mm金属、海藻酸钙可见彗星尾征或后方回声衰减.动物实验显示,空气、PGA可吸收手术缝线、5mm金属、超声耦合剂4种标记物植入实验犬肝内其超声可视性及持久性均较好.消融后即刻二维超声示上述4种标记物均可见;消融第7天复查超声示5mm金属仍清晰显示,大体标本示仅植入金属肉眼可见.穿刺植入过程中实验犬呼吸、心跳平稳,消融后7d内均未发生出血、感染等并发症,病理组织学检查示肝组织均未见损伤.结论 空气在二维超声图像中显示清晰、持久,且材料容易获取,有望作为临床应用的定位标记物,以指导适形消融肝肿瘤;超声耦合剂和声诺维-F127在二维超声图像中与肝实质回声差异明显,作为肝内标记物可能成为其临床新用途;金属在射频消融后能稳定保留,可作为肝肿瘤长期定位的理想标记.
Abstract
Objective To screen the materials that can be used as markers for visualization of intrahepatic localization by ultrasound,and to analyze the effect in guiding ultrasound-guided radiofrequency ablation(RFA)of intrahepatic tumors.Methods A total of 24 medical materials were selected in this study,including 1 gas,18 liquids and 5 solids.In bovine liver experiment in vitro,ultrasound-guided puncture was performed and localization markers were inserted or injected into the bovine liver.Then the visibility and persistence in situ of the markers were evaluated.Further,local ablation was performed at the distances of 1.0 cm,0.5 cm and 0 cm between the radiofrequency electrode needle and the markers,the effect of the thermal field on the markers was analyzed.In animal experiment,visualized localization markers were put into the liver of living beagle dogs under the guidance of ultrasound,then the visibility and persistence in situ of the markers were evaluated.The occurence of complications of animals were observed after RFA,and reexamined by ultrasound on the 7th day,the dogs were executed,then the ablation sites were dissected to observe the markers location and the liver tissue damage.Results In vitro experiments showed that air,gelatin sponge,PGA absorbable suture,5 mm metal,SonoVue-F127,calcium alginate,ultrasonic couplant and lauromacrol had good ultrasound visibility and persistence.After RFA,at 0.5 cm and 1.0 cm away from the ablation needle,various markers can be clearly displayed in two-dimensional ultrasound images without being affected by ablation thermal field.After ablation directly adjacent to the markers,only 5 mm metal and calcium alginate showed comet tail signs or backward attenuation.Animal experiments showed that air,PGA absorbable suture,5 mm metal and ultrasonic couplant had good ultrasound visibility and persistence after implanted into the dog liver.Immediately after RFA,the above four material markers were visible by two-dimensional ultrasound.On the 7th day after RFA,the 5 mm metal was still clearly displayed by ultrasound,and only metal implants were visible macroscopically in gross specimens.The breathing and heartbeat of the dogs were stable during the puncture implantation,and no complications such as bleeding and infection occurred within 7 d after RFA.No liver tissue damage was found by histopathological examination.Conclusion The gas marker with clear and durable visibility and simple availability,while controlling injection speed and dosage,is expectably served as a location marker to guide precise ablation needle placements.As to the ultrasonic couplant and the SonoVue-F127 showing obvious difference with hepatic background echo,intrahepatic marker may become a new clinical application.The metal can remain stable in situ after RFA making it an ideal marker for long-term tumor localization.
基金项目
国家自然科学基金(81971718)
北京市自然科学基金(7222020)
北京大学肿瘤医院科学研究基金学科发展项目(XKFZ2307)
NETL
NSTL
维普
万方数据