Weng Lihui, Seelig Davis, Rostamzadeh Parinaz, Golzarian Jafar
Department of Radiology, University of Minnesota, Mayo B228, 420 Delaware Street SE, Minneapolis, MN 55455.
Department of Veterinary Clinical Sciences, University of Minnesota, St Paul, Minnesota.
J Vasc Interv Radiol. 2015 Dec;26(12):1887-94.e1. doi: 10.1016/j.jvir.2015.01.014. Epub 2015 Mar 29.
To evaluate the time frame of resorption and tissue response of newly developed bioresorbable microspheres (BRMS) and vessel recanalization after renal embolization.
Embolization of lower poles of kidneys of 20 adult rabbits was performed with BRMS (300-500 µm). Two rabbits were sacrificed immediately after embolization (day 0). Three rabbits were sacrificed after follow-up angiography at 3, 7, 10, 14, 21, and 30 days. The pathologic changes in the renal parenchyma, BRMS degradation, and vessel recanalization were evaluated histologically and angiographically.
Embolization procedures were successfully performed, and all animals survived without complication. Infarcts were observed in all kidneys that received embolization harvested after day 0. Moderate degradation of BRMS (score = 1.07 ± 0.06) was observed by day 3. Of BRMS, 95% were resorbed before day 10 with scant BRMS materials remaining in the arteries at later time points. Partial vessel recanalization was observed by angiography starting on day 3, whereas new capillary formation was first identified histologically on day 7. Vascular inflammation associated with BRMS consisted of acute, heterophilic infiltrate at earlier time points (day 3 to day 10); this was resolved with the resorption of BRMS. Inflammation and fibrosis within infarcted regions were consistent with progression of infarction.
BRMS were bioresorbable in vivo, and most BRMS were resorbed before day 10 with a mild tissue reaction. Vessel recanalization occurred secondary to the resorption of BRMS.
评估新开发的生物可吸收微球（BRMS）的吸收时间框架、组织反应以及肾栓塞术后血管再通情况。
用BRMS（300 - 500 µm）对20只成年兔的肾下极进行栓塞。栓塞后立即处死2只兔（第0天）。在第3、7、10、14、21和30天进行随访血管造影后处死3只兔。通过组织学和血管造影评估肾实质的病理变化、BRMS降解及血管再通情况。
栓塞操作成功完成，所有动物均存活且无并发症。在第0天之后收获的所有接受栓塞的肾脏中均观察到梗死灶。到第3天观察到BRMS有中度降解（评分 = 1.07 ± 0.06）。在第10天之前，95%的BRMS被吸收，在后期时间点动脉中仅残留少量BRMS物质。血管造影显示从第3天开始出现部分血管再通，而组织学上首次在第7天发现新的毛细血管形成。与BRMS相关的血管炎症在早期时间点（第3天至第10天）表现为急性、嗜异性浸润；随着BRMS的吸收，炎症消退。梗死区域内的炎症和纤维化与梗死进展一致。
BRMS在体内可生物吸收，大多数BRMS在第10天之前被吸收，组织反应轻微。血管再通是BRMS吸收的继发结果。
