Laparoscopic Nissen fundoplication with carbon dioxide pneumoperitoneum preserves cell-mediated immunity in an immature animal model

Purpose: The aim of this study is to elucidate the effects of laparoscopic Nissen fundoplication (LNF) with carbon dioxide (CO₂) or helium (He) on the cell-mediated immune response in a pediatric animal model compared with open Nissen fundoplication (ONF). Methods: Cell immune response was evaluated in 45 1-week-old Sprague Dawley rats using the delayed type hypersensitivity (DTH) skin test. Animals were sensitized against keyhole limpet hemocyanin (KLH) by subcutaneous injection (0.5 mg) in complete Freund's adjuvant. Animals were challenged 2 weeks later by an intradermal injection of KLH (0.3 mg) in sterile saline (challenge 1, baseline). Rats with positive DTH skin reaction at 24 and 48 hours after challenge 1 were put randomly into 4 groups (n = 10 each): I, only anesthesia (control); II, LNF with CO₂, III, LNF with He; IV, ONF. Animals were injected intradermally with KLH (0.3 mg) immediately before the procedures (challenge 2) and 3 and 6 days postoperatively (challenges 3 and 4). Results: DTH skin reactions were measured 24 and 48 hours after each challenge, There were no significant changes in cell-mediated immunosuppression after LNF with CO₂. However, a transient cell-mediated immunosuppression was observed after LNF with He and ONF. All fundoplications were intact at the time of necropsy. Conclusions: These data suggest a transient suppression of cell-mediated immunity in open procedures when compared with laparoscopic interventions using CO₂ in a pediatric animal model. In addition, the type of gas used during laparoscopy also may modulate this transient immunosuppression.