Effects of laparoscopy on intraperitoneal tumor growth and distant metastases in an animal model

Background and aims: Laparoscopic surgery for colorectal cancer is currently being evaluated in humans. The aim of this study was to examine the effect of laparoscopy on intraperitoneal tumor growth and distant metastases in an animal model. We also examined the effect of combining laparotomy with laparoscopy and on infusing the peritoneal cavity with normal saline solution (NaCl), water, and sodium hypochlorite after laparoscopy on intraperitoneal tumor growth. Material and methods: Female Fischer rats were given MtLn3 adenocarcinoma cells by intraperitoneal injection to produce intraperitoneal tumor growth and by tail vein injection to produce lung metastases. A pneumoperitoneum was then induced to a pressure of 8 mm Hg with carbon dioxide (CO2), helium, or room air. After this, animals were allowed to either recover or underwent laparotomy or infusion of NaCl, water, or sodium hypochlorite before recovery, depending on the experiment. At 21 days all animals were killed and intraperitoneal tumor growth was assessed by counting the number of peritoneal and serosal nodules and by weighing the omental pad of tumor. Lung metastases were assessed by counting the number of metastases after fixation. Results: Laparoscopy caused a marked intraperitoneal dissemination of tumor with a median of 17 (10 to 20) peritoneal and serosal nodules for CO2, 19.5 (12.5 to 25) for helium, and 15.0 (9.5 to 17.7) for room air compared with 0 (0 to 1) for controls (P <.0001). The weight of omental tumor was also significantly increased (P <.02) in the CO2, helium, and room air groups. Infusion with NaCl, water, or sodium hypochlorite had no effect on tumor dissemination after laparoscopy. The combination of laparoscopy and laparotomy caused a significant reduction (P <.05) in the number of peritoneal nodules but had no significant effect on omental tumor growth. Laparoscopy also had no effect on the number of pulmonary metastases induced compared with controls. Conclusions: This study shows that laparoscopy promotes intraperitoneal dissemination of tumor. This effect is independent of the insufflating gas used and is not affected by use of a cytotoxic agent. The use of gasless laparoscopy should be encouraged by those undertaking curative laparoscopic surgery for colorectal cancer

Effects of laparoscopy on intraperitoneal tumor growth and distant metastases in an animal model

Background and aims: Laparoscopic surgery for colorectal cancer is currently being evaluated in humans. The aim of this study was to examine the effect of laparoscopy on intraperitoneal tumor growth and distant metastases in an animal model. We also examined the effect of combining laparotomy with laparoscopy and on infusing the peritoneal cavity with normal saline solution (NaCl), water, and sodium hypochlorite after laparoscopy on intraperitoneal tumor growth. Material and methods: Female Fischer rats were given MtLn3 adenocarcinoma cells by intraperitoneal injection to produce intraperitoneal tumor growth and by tail vein injection to produce lung metastases. A pneumoperitoneum was then induced to a pressure of 8 mm Hg with carbon dioxide (CO2), helium, or room air. After this, animals were allowed to either recover or underwent laparotomy or infusion of NaCl, water, or sodium hypochlorite before recovery, depending on the experiment. At 21 days all animals were killed and intraperitoneal tumor growth was assessed by counting the number of peritoneal and serosal nodules and by weighing the omental pad of tumor. Lung metastases were assessed by counting the number of metastases after fixation. Results: Laparoscopy caused a marked intraperitoneal dissemination of tumor with a median of 17 (10 to 20) peritoneal and serosal nodules for CO2, 19.5 (12.5 to 25) for helium, and 15.0 (9.5 to 17.7) for room air compared with 0 (0 to 1) for controls (P <.0001). The weight of omental tumor was also significantly increased (P <.02) in the CO2, helium, and room air groups. Infusion with NaCl, water, or sodium hypochlorite had no effect on tumor dissemination after laparoscopy. The combination of laparoscopy and laparotomy caused a significant reduction (P <.05) in the number of peritoneal nodules but had no significant effect on omental tumor growth. Laparoscopy also had no effect on the number of pulmonary metastases induced compared with controls. Conclusions: This study shows that laparoscopy promotes intraperitoneal dissemination of tumor. This effect is independent of the insufflating gas used and is not affected by use of a cytotoxic agent. The use of gasless laparoscopy should be encouraged by those undertaking curative laparoscopic surgery for colorectal cancer

Acquired abnormalities of the biliary tract from chronic gallstone disease11No competing interests declared

Background: Acquired abnormalities of the biliary tract from chronic gallstone disease are rare. The aim of this study was to examine the frequency with which these abnormalities occur and to assess the probability of encountering such an abnormality at laparoscopic cholecystectomy. Study Design: We conducted a prospective study of all patients undergoing elective and emergency cholecystectomy under the care of one surgeon between January 1991 and December 1997. Results: Biliary tract abnormalities from chronic gallstone disease were encountered in 10 (2%) of 486 patients undergoing cholecystectomy. Four were observed in patients undergoing elective laparoscopy cholecystectomy, and the remainder were observed at open cholecystectomy. Five had a cholecystocholedochal fistula (Mirizzi Syndrome Type II), and one had a stone impacted at the cystic duct-bile duct junction (Mirizzi Syndrome Type I). Two had cholecystoduodenal fistulas and two had an absent cystic duct with a normal bile duct. Both instances of an absent cystic duct were encountered at laparoscopic cholecystectomy; in one the bile duct was mistaken for the cystic duct and a 2-cm segment was excised at operation, and in the other the abnormality was recognized and confirmed by cholangiography. Conclusions: This study demonstrates a similar incidence of acquired abnormalities of the biliary tract from chronic gallstone disease to that already reported. But acquired absence of the cystic duct may occur more frequently than previously suspected. Patients with this condition are at high risk for bile duct injury during laparoscopic cholecystectomy. Clinical awareness of this problem with strict adherence to the principles taught at open cholecystectomy may prevent or reduce the severity of bile duct injury in these patients