高强度聚焦超声辐照猪胰腺实验研究

目的探讨改善胰腺HIFU辐照超声通道的方法,并了解不同能量HIFU辐照对猪胰腺组织的损伤及对胃肠道的影响。方法以2头新鲜离体猪胰腺和16头在体猪胰腺体部为靶目标,活体实验中,HIFU辐照前在12头猪胃内放置球囊并注入800~1200ml脱气水,分别以高、中、低能量HIFU进行辐照,4头猪未放置球囊并以中等能量辐照,通过光镜和电镜检查观察胰腺病理损伤程度,并观察副损伤发生情况。结果胃内放置水囊后高能量组4头猪胰腺凝固性坏死程度最重,1头发生皮肤烧伤,2头结肠坏死或穿孔,4头胃黏膜损伤;中等能量组4头猪胰腺凝固性坏死程度较轻,1头发生结肠坏死;低能量组胰腺组织凝固性坏死不明显,但电镜下可见细胞器损伤,1周后出现胰腺坏死现象,未发生皮肤、胃及结肠损伤;未放置水囊组4头猪中只有1头光镜下见胰腺点状坏死,皮肤、胃及结肠的损伤较放置水囊组明显加重。结论通过胃内放置水囊的方法可有效改善猪胰腺HIFU超声通道,高能量HIFU辐照猪胰腺更易发生凝固性坏死,但对胃、结肠的损伤较重;中低能量HIFU可引起猪胰腺发生多种形式损伤或坏死,损伤程度相对较轻,但相对安全。

Radiation of high intensity focused ultrasound to pig pancreas: experimental study

Objective To explore the methods of establishing the HIFU for pig pancreas passage and to evaluate the efficacy and safety of different HIFU energy degree. Methods Two pig pancreas in vitro and 16 pig pancreatic bodies in vivo were irradiated by different HIFU levels, a water sac was placed into pig stomach and 800-1000 ml degassed water was filled into the water sac in 12 pigs. No water sac was placed into the stomach in 4 pigs. The pancreatic pathologic and microstructural changes and complications were observed.Results In water sac (WS) group, the pancreatic injury degree by high-energy HIFU was the heaviest: 1 case was with skin burn; 2 with colon necrosis or perforation and 4 with stomach mucosa damage; the pancreatic injury degree by middle-energy HIFU was fairly light: 1 case was with colon necrosis; the pancreatic coagulative necrosis by low-energy HIFU was not obvious, but organelle damages were really observed on electron microscope. Necrosis happened 1 week later, but no skin, stomach and colon damage happened. In no water sac(NWS) group small dot necrotic foci were observed on microscope in only 1 pig, but the skin, stomach and colon damages were more servere than in WS group. Conclusions It is improved that the HIFU passage in pancreas can be established by placing a water sac into stomach and filling degassed water into it. High-energy HIFU is more effective and also more dangerous for pig pancreatic ablation; although the middle and low-energy HIFU may cause the pancreatic damage or necrosis in vivo, the necrosis may not be complete. Therefore, middle and low energy is more safer and more feasible in clinical.