Faculty Bibliography

BACKGROUND:Several series of laparoscopic colon resection have been reported in the literature with varied results; however, no controlled series of laparoscopic vs open colon resection has been reported. The purpose of this study was to determine the relative safety and adequacy of laparoscopic colon resection in a controlled trial using a porcine model. METHODS:Domestic pigs (n = 23) were randomly divided into two groups. Animals underwent either an open or laparoscopic-assisted segmental resection of the sigmoid colon. The open resections were performed through a 20-cm midline incision and the laparoscopic technique utilized five 12-mm ports. Laparoscopic resection took twice as long to complete as open resection (P < 0.001). Return of gastric function was significantly faster in the laparoscopic group than in the open group (P < 0.032). RESULTS:No significant differences were found in total length of resection, proximal or distal margins, number of lymph nodes recovered, length of mesenteric vessel resected, or time to return of bowel function. At vivisection, more adhesions to the abdominal wall were noted in the open group (P < 0.002). One death occurred in the laparoscopic group 2 h postoperatively (8.3% mortality) while all open group pigs survived. However, there was no statistically significant difference in mortality rates by chi-square analysis (P > 0.5). CONCLUSIONS:Despite longer operative time, laparoscopic intervention is technically feasible, safe, and may offer significant postoperative benefits due to fewer abdominal adhesions.

OBJECTIVE:To test our hypothesis that tumors would be more easily established and grow more aggressively after laparotomy than after laparoscopy. This hypothesis was based on studies that have demonstrated that surgery can suppress immune function and facilitate tumor growth and that have shown preservation of immune function after laparoscopic procedures. DESIGN/METHODS:Double-blinded, randomized, control trial. SETTING/METHODS:Research laboratory and animal care facility. ANIMALS/METHODS:One hundred forty 5- to 6-week-old C3H/He female mice. INTERVENTIONS/METHODS:Three experiments with three groups each: laparotomy, insufflation, and anesthesia controls. All animals received an intradermal inoculation of tumor cells in the dorsal skin. The anesthesia control cohort underwent no procedure. The laparotomy cohort underwent a midline laparotomy from the xiphoid process to the pubis, which was closed after 30 minutes. The insufflation cohort underwent peritoneal insufflation with carbon dioxide for 30 minutes. MAIN OUTCOME MEASURES/METHODS:Tumor volume, tumor mass, and incidence of tumor establishment. RESULTS:In the first experiment, the tumor volumes of the anesthesia control and insufflation groups followed a similar pattern of plateau and regression. The tumor volumes of the laparotomy group followed a different pattern and were significantly larger than those of the control and insufflation groups on postoperative days 6 and 12 (P < .05 for all comparisons). In the second experiment, tumors in the laparotomy group were approximately three times larger than those of the control group (P < .01) and almost twice as large as insufflation group tumors (P < .01) by mass. In the third experiment, there was a significantly higher incidence of tumor establishment in the laparotomy group than in the insufflation (P < .04) or control (P < .01) groups. The incidence was not different between the control and insufflation groups. CONCLUSIONS:Tumors were more easily established and grew more aggressively after laparotomy than after insufflation. These results, coupled with those that demonstrate an immune advantage to laparoscopy over laparotomy, suggest that the difference in observed tumor growth may be related to immune function. While much work remains to be done, we believe these data provide evidence of a previously undemonstrated benefit of laparoscopic intervention.

We investigated the effects of laparotomy and insufflation on tumor establishment and growth in a murine model. Twenty female mice received intradermal inoculation of a low dose of tumor cells (2 x 10(3)) derived from the MC2 mouse mammary carcinoma cell line. Ten of these mice underwent laparotomy and ten received intraperitoneal insufflation with carbon dioxide gas at a pressure of 5 mmHg for 30 min. Tumor growth was followed postoperatively. By postoperative day 14, tumors had grown in zero of the ten insufflated mice and in seven of the ten laparotomy-group mice (P < 0.005). By postoperative day 30, tumors had grown in one of the ten insufflated mice and in eight of the ten laparotomy-group mice (P < 0.007). Ten additional mice received a high-dose inoculum of cells (1 x 10(6)) followed by either laparotomy or intraperitoneal insufflation. Upon sacrifice 12 days later, all mice had developed tumors, but the laparotomy group's tumors were almost three times as large, by mass, as tumors in the insufflated group (70.5 +/- 23.5 mg vs 25.8 +/- 9.5 mg; P < 0.02). These results suggest that laparotomy confers a permissive effect on tumor establishment and growth in a murine model not seen after peritoneal insufflation. We hypothesize that this may be a function of relative immunosuppression following laparotomy which is not present following peritoneal insufflation. These data may be important when choosing a route of access to the peritoneal cavity for cancer resection.