The Immuno-inflammatory Effects Of Transgastric Endoscopic Peritoneoscopy Versus Laparoscopy In Male Rabbits

Objective:Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a new concept inthe area of minimal invasive surgery, which conceives certain potential advantagesversus traditional laparoscopic techniques. However, it remains controversial aboutthe immuno-inflammatory effects of transgastric endoscopic surgical techniquescompared with laparoscopic techniques. The aim of this study is to establish malerabbit models for transgastric endoscopic peritoneoscopy and laparoscopy,investigating their safety and feasibility, as well as the differences on the systemicinflammatory responses and cell-mediated immune responses, just by detecting thechanges of the serum cytokines and the function of peripheral blood mononuclearcells (PBMC) perioperatively.Methods:Sixteen male Japanese white rabbits (conventional animals,10~12weeks age,2~2.5kg weight) were randomly divided into two groups of eight animals andsubjected to transgastric endoscopic peritoneoscopy (N group) and laparoscopy (Lgroup). A group of five animals served as a sham group (S group). Animals from Ngroup were used to establish a model for transgastric endoscopic peritoneoscopymainly through a fibrocholedochoscope, and animals from L group were used toestablish a model for laparoscopy mainly through a laparoscope. No furtherinterventions were made for animals from S group, while the procedures of anesthesiaand perioperative managements were consistent with the operation groups.Exploration outcomes, intervention durations, complications and deaths wereobserved. Blood samples were drawn from the ear arteries preoperatively (PRE) andfour hours (POH4),24hours (POH24) and72hours (POH72) postoperatively. Thepro-inflammatory cytokines serum levels of tumor necrosis factor-α (TNF-α) andinterleukin-6(IL-6), together with the anti-inflammatory cytokine serum level ofinterleukin-10(IL-10), were detected by enzyme linked immunosorbent assays(ELISA), and were compared among groups afterwards. Then PBMC were isolated and cultured in vitro, stimulating by lipopolysaccharide (LPS). TNF-α level of thecell supernatants was detected by ELISA, and was also compared among groupsafterwards.Results:1. The establishment of the male rabbit models for transgastric endoscopicperitoneoscopy and laparoscopy was succeeded. The surgical time was longer for Ngroup than L group. There existed two complications in N group, one was dead due togastric leak eighteen hours postoperatively, and the other one died of unknownorigins four hours postoperatively. One complication occurred in L group, whichfinally resulted in death due to hepatorrhagia. Other animals survived more than threedays and recovered well. There were no abnormal outcomes in the autopsy sevendays postoperatively.2. The pro-inflammatory cytokines serum levels of TNF-α and IL-6did not differstatistically among groups preoperatively, so did in the S group perioperatively.Significant increases of TNF-α serum level were seen in both N group and L group onPOH4, the former appeared later but lasted longer. TNF-α serum level wassignificantly higher in L group on POH4, and it was just on the contrary on POH24.IL-6serum level increased significantly in both N group and L group on POH24, theformer began to decrease on POH72, but not seen in the latter. IL-6serum level wassignificantly lower in L group than N group on POH4, and it was just on the contraryon POH72.3. The anti-inflammatory cytokine serum level of IL-10did not differ statisticallyamong groups preoperatively, so did in the S group perioperatively. IL-10serum leveldid not differ from baseline level in N group, but it decreased significantly in L groupon POH24, and remained low on POH72. IL-10serum level was higher in N groupthan L group both on POH24and POH72.4. The in vitro TNF-α secretion by PBMC did not differ statisticallyperioperatively in any group, and so did among groups at different time points.Conclusion:1. It was feasible to accomplish transgastric endoscopic peritoneoscopy using afibrocholedochoscope and relevant auxiliary instruments on male rabbits, but the surgical time was longer compared with traditional laparoscopy. Gastric leak andadjacent organ injury served as severe complications, and might lead to death inserious cases. It remained to be improved on the surgical instruments and techniques.2. Both of the interventions evoked the systemic pro-inflammatory responses,and varied from the occurring time and duration. However, it was generally inaccordance with the characters of the systemic pro-inflammatory responses evoked bysurgical trauma.3. The anti-inflammatory responses did not change significantly after transgastricendoscopic peritoneoscopies, but it was consistently reduced after the lararoscopieson POH24and POH72, and therefore remained to be further investigated.4. The in vitro TNF-α secretion from PBMC did not vary significantly during thefirst three days postoperatively, and there were no significant differences amongdifferent groups. It might be significant if subjected to greater interventions or beingdynamically monitored for long term.