射频消融对活体动物肢体长骨的损毁情况

The radiofrequency ablation-induced damage to the long bone of limb: an experimental study in pigs

目的通过对活体猪胫骨的骨端和骨干进行射频消融术(percutaneous radiofrequencyablation,RFA),探讨其对活体长骨的损毁效果,为骨肿瘤的临床RFA治疗提供依据。方法取活猪3头,麻醉下行胫骨的骨干、骨端RFA,于RFA后即刻处死动物,获取骨干、骨端标本,观察RFA对骨端、骨干及其周围组织结构的损毁情况。结果肉眼观察RFA灶见中部为灰白色、椭圆形的凝固性坏死区,周围呈灰褐色的出血充血带,外围为正常组织区。骨端松质骨RFA灶坏死面积平均为(4.08±0.73)cm2,最大为5.24 cm2;骨干骨髓RFA灶坏死面积平均为(7.58±1.41)cm2,最大为8.98 cm2。骨端松质骨RFA灶坏死面积小于骨干内骨髓RFA灶坏死面积,二者均小于RFA-Ⅰ型射频肿瘤消融系统标定的RFA坏死面积(软组织内单次RFA)。RFA对骨端及骨干密质骨的直接损毁作用甚微,镜下观察见消融针道旁的密致骨坏死区宽0.01 cm,且紧邻消融灶的密质骨及其周围的肌肉等软组织坏死现象不明显。结论 RFA可以有效损毁松质骨和骨髓组织。RFA对松质骨的直接损毁范围略小于软组织,对骨髓组织的损毁在长骨纵径方向略长于软组织,但对密质骨的直接损毁作用有限。完整的密质骨可以阻挡热量的传导,能有效保护周围重要组织。

Objective To investigate the radiofrequeney ablation-induced destruction effect on pig＇s long bone by percutaneous radiofrequeney ablation （RFA） of epiphysis and diaphysis of pig＇s tibia in vivo in order to provide useful fundamental knowledge for guiding clinical RFA treatment of bone tumors. Methods Under general anesthesia, DSA- guided percutaneous RFA of epiphysis and diaphysis of pig＇s tibia was performed in three pigs. The animals were sacrificed immediately after RFA procedure. The samples of epiphysis and diaphysis were collected and sent for pathologic examination. The results were analyzed. Results Macroscopically, RFA-indueed lesion took the form of grayish, oval-shaped coagulation necrosis at its center with a brownish-grey congested zone around, the periphery presented as normal tissue area. In the cancellous bone of the diaphysis the RFA-induced necrosis lesion had a mean size of （4.08 ±0.73 ） cm^2 with the largest one of 5.24 cm^2, while in the bone marrow of the epiphysis the RFA-induced necrosis lesion had a mean size of （7.58 ±1.41） cm^2 with the largest one of 8.98 cm^2. The RFA-induced necrosis size in the diaphysis cancellous bone was smaller than that in the epiphysis bone marrow, but both necrosis sizes were smaller than that calibrated by RFA- I type radiofrequency tumor ablation system （a single RFA procedure for soft tissue）. RFA had little direct destruction effect on the compact bone of both epiphysis and diaphysis. Microscopically, the necrosis size of the compact bone around the ablation needle path was only 0.01 em in width, and the neighboring soft tissue such as muscles showed no obvious necrosis. Conclusion RFA can effectively damage spongy bone and bone marrow tissue. The directly destructed extent of spongy bone by RFA is a little bit smaller than that of soft tissue. The RFA- destructed extent of bone marrow tissue along the longitudinal axis of a long bone is slightly larger than that of the soft tissue, but the direct damage of RFA to the compact bone is quite limited. An intact compact bone can effectively stop the heat conduction,so the surrounding important organs can be effectively protected.