The Great Radicular Artery (GRA) with F-P Complex Monitoring (FPC) could be identified by the animal experiment which had been conducted before.

自1998年以来，我们调查了化学注入（例如，KC1）对FPC鉴别GRA有无意义。我们的结论是，这种识别方法是不可能的，因为一个导管，引入腹主动脉引起FPC的变化，由于脊髓缺血。现在，我们正在进行慢性实验研究，用兔子检测脊髓缺血，结扎4腰动脉。经左侧腹膜外入路显露肾下腰动脉，结扎与GRA无关的最头侧动脉。取3条连续动脉夹闭，观察FPC的变化。A组7例，观察到波形下降时，保留3支中的中央1支，其余3支均结扎。B组5例，在无血管改变时结扎3支动脉。第2天检查术后截瘫情况。术后一天作为对照实验，C组5例，观察到波压低时结扎3支动脉。第2天5例中有4例出现截瘫。C组术后第1天。而A、B组均无神经功能缺损。第2天，我们从剩余的腰动脉进行了选择性动脉造影，并研究了与GRA的关系。术后一天或更晚。结果表明，侧支循环可保护GRA和脊髓前动脉，并可避免截瘫的发生，因此，无论是否为GRA，保留一侧腰动脉的方法对胸腹联合动脉瘤手术避免截瘫是有益的。

Since 1998, we investigated that chemical injection (ex. KC1) to the lumbar artery was useful or not to identify the GRA with FPC. We concluded that this method for identification was impossible because a catheter which was introduced in the abdominal aorta caused FPC change due to spinal cord ischemia.Now, we are proceeding chronic experimental study using rabbits to detect spinal cord ischemia by the ligation of 4 lumbar arteries. The infra renal lumbar arteries were exposed by left extraperioneal approach, then the most cranial one that is not related to the GRA was ligated. We selected 3 consecutive arteries and observed the change of FPC by clampping the arteries. When we observed depression of the wave, central 1 among 3 was preserved and other all 3 arteries were ligated (7 cases, group A ). When we observed no chage, these 3 arteries were ligated (5 cases, group B). The postoperative paraplegia was examined in the 2nd. post operative day. As a control experiment, 3 arteries were ligated when depression of the wave was observed (5 cases, group C). Paraplegia was observed in 4 of 5 cases in the 2nd. postoperative day in group C. Whereas no neurological deficit was observed in each group A or B.We performed selective arteriography from remaining lumbar artery and investigated relations with the GRA in the 2nd. post operative day or later. As a result, we could observe that the GRA and anterior spinal artery were preserved by collateral circulation' and paraplegia could be evaded by these blood flow.In conclusion, this method, preservation of one lumbar artery whether/it is GRA or not, is useful to evade paraplegia in the thoracoabdominal aoritc aneurysm surgery.