Experimental Study on the Effect of Temporary Clipping on the Histological Changes of the Arterial Walls of Rats

Temporary occlusion of the parent artery or feeding artery is an useful method in microsurgery for cerebrovascular diseases. The advantages of the temporary clipping for intracranial aneurysm surgery have already been proven by many experimental and clinical reports. Currently, there are two methods of temporary clipping: 1) intermittent clipping, 2) continuous clipping. In many previous studies, the intermittent, repeated clipping technique was reported to reduce ischemic damage to the brain, but it is still debated. On the other hand, a comparison of the histological changes on the arterial wall between each clipping method has not been sufficiently reported yet. So the authors performed experimental temporary clipping on the common carotid and femoral arteries of about 25 rats using the Sugita temporary mini-clip. The specimens were divided into two major groups and seven subgroups: Group I (I-1, I-2, I-3, I-4, intermittent clippings for 5 minutes were done once, twice, three times, and few times), and Group C (C-10, C-15, C-20, continuous clippings for 10, 15, 20 minutes, respectively). The reperfusion time after the temporary clipping was the same as the clipping duration. Under light microscope, the histological findings by Hematoxylin-Eosin staining were examined in all specimens, which were obtained at each time interval after temporary clipping. Then the histological changes of the arterial walls by two different methods were compared with the normal specimen. The results suggest that intermittent temporary clipping is less damaging on the arterial wall than single continuous clipping.