Postoperative Growth and Food Intake After Minimally Invasive Surgery in an Immature Murine Model

Abstract

ABSTRACT

The effects of minimally invasive surgery (MIS) on postoperative nutrition and food intake have not been reported. We compare the effects of MIS access techniques on postoperative status by analyzing the changes in body weight and food intake in an immature mouse model. Immature 5- to 7-week-old male A/J mice underwent laparotomy under general inhalational anesthesia (n = 20/group). In addition, two other groups of mice underwent MIS using either pneumoperitoneum with carbon dioxide (CO₂) or gasless suspension (n = 20/group). Operative and anesthetic times were equal for all groups. Body weight and the amount of food and water intake were recorded over a 2-week postoperative period. Data were analyzed statistically by ANOVA and p < 0.05 was considered to be significant. The postoperative percentage decrease in body weight was significantly greater after laparotomy than after either MIS or anesthetic control (−14.9 ± 3.6% vs. preoperative body weight, −11.0 ± 3.2% in pneumoperitoneum group, and −10.9 ± 3.5% in anesthetic control). The time to return to the preoperative body weight was also significantly longer after laparotomy (11.4 ± 2.6 days vs. 5.6 ± 3.3 days after pneumoperitoneum and 3.9 ± 2.1 days after anesthesia only). This finding may be explained by a significant decrease in the amount of food and water intake during the first 3 postoperative days following laparotomy. There were no significant differences between the two MIS groups in any of the parameters studied, however, the gasless suspension group demonstrated a retarded recovery in postoperative body weight when compared to the anesthetic control group. We conclude that postoperative morbidity as assessed by the nutritional parameters studied is significantly improved by MIS access techniques. We speculate that the physiologic advantage provided by MIS procedure when compared with laparotomy may, in part, be secondary to preservation of host nutritional status during the early postoperative period.