应用离体猪肾脏模型探索微波消融治疗肾脏肿瘤的消融范围和特点

Experimental study on ablation zone and characteristics of microwave ablation in porcine kidney in vitro

目的 明确不同功率和作用时间下微波消融治疗肾脏肿瘤的消融范围和特点.方法 采用前极为1.10 cm的水冷循环微波针,工作频率为2 450 MHz,输出功率为50 ～ 70 W,消融时间为240 ～ 600 s,以不同的功率和时间组合对离体猪肾脏进行消融,观察消融灶的形状、测量消融范围,留取标本应用HE染色明确消融灶的病理特点.结果 有效消融组织的形状呈栗子形,随着功率和时间的增加,消融灶的范围逐渐增大,数据显示50 W/480 s、60 W/300 s、70 W/240 s 3组消融灶的最大横径接近于3.00 cm,长径约3.30 cm.消融灶包括炭化区、凝固区和移行区3部分.相同作用时间下,随着功率增大,移行区范围增大.组织病理显示炭化区中肾组织大片坏死,伴多量碎核,肾小球、肾小管变形,肾小管上皮脱落,血管内皮细胞变性坏死,消融得十分彻底;凝固区肾组织发生凝固性坏死,镜下病理可见残存的肾小球、肾小管和肾血管轮廓,但结构紊乱,管腔闭塞,丧失生物学活性;移行区绝大部分为正常肾组织,但散在出现肿胀的细胞,存在热损伤.结论 作为一种新的能量治疗方式,微波消融可以安全有效地用于治疗≤3 cm的肾脏肿瘤.

Objective To observe the ablation zone and characteristics of microwave ablation with different power and time in the model of porcine kidneys in vitro.Methods 2 450 MHz water circulative-cooling microwave needles were used,and the length of the anterior pole was 1.10 cm.The independent variables were power （50-70 W）,time （240-600 s） and ablated with different combinations.The ablation shape,zone and pathological characteristics were observed.Results The effective ablation shape was similar to a chestnut and the ablation zone enlarged with the increasing of power and time.When combined with 50 W/480 s,60 W/300 s,70 W/240 s,the largest transverse-diameter of the ablated tissue was close to 3.00 cm and the length-diameter was about 3.30 cm.The pathological characteristics indicated that renal tissues of carbonization zone were thoroughly necrotic.Coagulative necrosis was observed in coagulation area,though there were residual profile of glomerutus,renal tubular and vessels,they had lost activity.Most of the tissues in transition zone were normal,however,some cells were swelling because of thermal damage.Conclusion Microwave ablation is an emerging thermal therapy which can be safely,effectively used in the treatment of renal tumors that are smaller than 3 cm.