中文摘要：

目的评价新型液．固相变材料Matrigel作为人工腹水在大鼠模型中减少射频消融（RFA）对肝周重要结构损伤的有效性及安全性。方法体外观察Matrigel在不同温度下的形态特征。将42只SD大鼠随机分Matrigel组、生理盐水组和对照组（每组14只）。Matrigel组和生理盐水组大鼠肝周注射10ml的Matrigel液体或生理盐水后即刻RFA，消融区分别紧邻膈肌、腹壁或胃肠。大鼠24h处死解剖（41只，1只死亡），进行病理学检测，比较各组肝周结构热损伤率。最后，随访大鼠的状态（10只），评价Matrigel的长期安全性。结果（1）Matrigel在0—4℃时流动性最大，呈液体状态。20℃3 min或37℃1 min时，流动性明显降低成凝胶状态。（2）肝周液体厚度比较，RFA前、1、3、5min时，Matrigel组比生理盐水组厚度明显增加，5min时差别最大[（8．1±1．1）mm比（2．4±0．8）mm，P〈0．01]。周围脏器的热损伤：对照组为12／13只，高于生理盐水组8／14只（P=0．037），生理盐水组高于Matrigel组（1／14只）（P=0．005）。各组之间肝消融的范围差异无统计学意义。（3）Matrigel组和生理盐水组60d的随访中两组大鼠的体质量和健康状态差异均无统计学意义。结论在对肝被膜下的肝肿瘤射频消融时，与传统生理盐水相比，液-固相变材料Matrigel作为人工腹水安全、有效，可以减少肝周结构热损伤的发生率和严重程度。

英文摘要：

Objective To evaluate the effect and safety of using thermo-sensitive Matrigel as artificial ascites on minimizing thermal injury to the nearby structures in a rat model of radiofrequency （RF） ablation of the liver. Methods In this research, the morphological characterization of Matrigel was observed at different temperatures in vitro. In vivo study was conducted by using 42 SD rats in Matrigel, Saline and control groups of 14 rats each. Artificial ascites with 10 ml of Matrigel or saline was produced under ultrasound guidance before RF in the experimental groups. Using a 0. 7 cm exposed 17 G RF electrode for 5 minutes （90 ± 2）℃, 41 hepatic ablations was performed abutting the diaphragm, abdominal wall and stomach. The 41 rats were sacrificed at 24 h, and necropsy was performed. Gross and histopathologic examinations were performed to compare the frequency and extent of thermal injury to the nearby organs. The animal status was followed up to achieve long term safety evaluation of Matrigel. Results Matrigel was in liquid formation at 0 - 4 ℃, but was not moving in vials at temperature 37℃ in 1 rain, presenting gel formation. In vivo experiment, the artificial fluid thickness of Matrigel in site was significant larger than that of saline group, especially at 5 rain of ablation （ （ 8. 1 ± 1.1 ）mm vs （2. 4 ± 0. 8 ） ram, P 〈 0. 01 ）. Thermal injury to the nearby structures was found in 12 of 13 cases in control group, 8 of 14 eases （P =0. 037） in saline group, and 1 of 14 cases （ P 〈 0. 01 ） in Matrigel group. The sizes of the ablation zone of the liver did not differ among the three groups. There was no difference in the incidence of operation related complications among the three groups. There was no significant difference in body weight and health related parameters between Matrigel and saline group during 60 days of follow up. Conclusions Using thermo-sensitive Matrigel as artificial ascites may be a safe and useful technique and help to further reduce the frequency and se