Study Of Tumor Cells' Activity In The Smog Produced By Ultrasonically Activated Scalpel In The Dissection Of Gastric Malignant Tumor

Objective: Through establishing an orthotopic gastric tumor model in nude mice, to study tumor cells and their activity in smog produced by ultrasonically activated scalpel during tissue incision on different power and time. Then to provide primary theory evidence for safe clinical using of ultrasonically activated scalpel in laparoscopic surgery.Method: RPMI-1640 add 10% calf serum as culture medium to culture poorly differentiated gastric cancer cells(SGC7901) in vitro, which were then inoculate in BALB/C(nu/nu) nude mice's gastric wall. After transplantation tumor grows in the gastric wall for 4 weeks, use ultrasonically activated scalpel at the third grade(60 % of full power) and the fifth grade(100%of full power) cutting the transplantation tumor for 5 seconds, 10 seconds, 15 seconds and 20 seconds respectively and collect all the different smogs. Culture the cells in the smog for two weeks and inoculate in BALB/C(nu/nu) nude mice's gastric wall again. Two months later, open the abdomen to observe the tumor.Results: No matter the power of ultrasonically activated scalpel is set at the third grade(60% of full power) or the fifth grade(100% of full power) ,while cutting the transplantating tumor for 5 seconds,there are few cells can be collected in the smog and there are not cells cultured for 24 hours. Cutting the transplantating tumor for 10 seconds,there are a little more cells than 5 seconds and they grow slowly. Cutting the transplantating tumor for 15 seconds and 20 seconds, there are much more cells and they can grow faster than 5 seconds and 10 seconds. But maybe there are defunct cells , impurity and other kinds of cells ,we can not count them accuratly. Culture the cells in the smog for and inoculate them in BALB/C(nu/nu) nude mice's gastric wall again. Two weeks later dissect the nude mice,we found :(1)No matter the power of Ultrasonically activated scalpel is set at the third grade(60%of full power) or the fifth grade(100 % of full power) ,while cutting the transplantating tumor for 10 seconds,there are not tumors growing in the gastric wall and the pathology test confirm it ; while cutting the transplantating tumor for 15 seconds and 20 seconds, there are tumors growing in the gastric wall and the pathology test confirm it too. (2) Use ultrasonically activated scalpel at the third and the fifth grade cutting the transplantation tumor for 15 seconds or longer , the diameter of tumor is about 4-6mm and 8-11mm.At the same time,the bearing cancer mice became marasmatic. (3)Using power in the third grade ,time of 15 seconds,20 seconds,the weights of tumor are following: 0.208±0.074g, 0.244±0.060g. Using power in the fifth grade ,time of 15 seconds,20 seconds,the weights of tumor are following: 0.337±0.083g, 0.346±0.053g. Statisics show: 1. the weights of tumor and sizes are in line with the power and cutting time of ultrasonically activated scalpel. 2, No matter the power of ultrasonically activated scalpel is set at the third grade(60%of full power) or the fifth grade(100%of full power), there is significant difference in the weights of tumor between time of 10 seconds and 15 seconds,the same to 10 seconds and 20 seconds. But there is not significant difference between time of 15 seconds and 20 seconds. 3. While cutting time is set at 10 seconds, there is not significant difference in the weights of tumor between power of 3 and 5. And while cutting time is set at 15 seconds or 20 seconds, there is significant difference between power of 3 and 5.Conclusion: In the laparoscopic surgery for gastric, cancer Ultrasonically activated scalpel is a safe surgical instruments. But while we use it cutting tumor directly,there are active tumor cells existing in the smog possibly, and the risk increases in line with the power and cutting time of ultrasonically activated scalpel. The cutting time could be more important. So in the laparoscopic surgery for gastric cancer,when we want to cut the tissue which maybe has been infiltrated by tumor ,or to clear the lymph nodes which maybe has been transferred, the ultrasonically activated scalpel should be set at a low power and one cutting time should not be more than 10s. It is of great importance to degrade the tumor cells' activity in the smog which produced by ultrasonically activated scalpel in the dissection of gastric malignant tumor and enhance the safety of the operation.