The impact of laparoscopic biopsy of pancreatic lymph nodes with helium and carbon dioxide on port site and liver metastasis in BOP-induced pancreatic cancer in hamster

The influence of pancreatic biopsy during laparoscopy with carbon dioxide ( CO2) and helium on the incidence of port site and liver metastasis in pancr eatic carcinoma is still unknown. Ductal adenocarcinoma of the pancreas was induced in Syrian hamsters (n=30) by injection of N-nitrosobis-2-oxopropyl amin (BOP, 10 mg/kg body weight/week) for 12 weeks. In week 13, hamsters we re randomized in 3 groups (n=10): While in group 1 (gr. 1) a laparotomy and biopsy of pancreatic lymph nodes was performed, gr. 2 and gr. 3 underwent a laparoscopic biopsy either with CO2 or helium. Therefore, one trocar was located in the left (biopsy) and the right abdominal wall (camera). In the 18th week all animals were sacrified and the incidence of abdominal wall, p ort site and liver metastases was histologically determined. While there we re abdominal wall metastases after laparotomy in 10% (n=1), we observed tro car metastases in the CO2 group in 20% (n=2). However, there were no trocar metastases in the helium group. The incidence of liver metastasis did not differ between the laparotomy and the helium group (20% vs 30%), but was in creased in the CO2 group (60%). Laparoscopic biopsy of pancreatic lymph nod es with CO2 increased the incidence of port site and liver metastases in pa ncreatic cancer. The helium group was equal to the laparotomy group in this respect. Thus, staging laparoscopy with helium might become an alternative to explorative laparotomy in pancreatic cancer.