Effects of laparoscopic carbon dioxide pneumoperitoneum on functions of liver and kidney in infant rabbits

Objective To explore the effects of different carbon dioxide pneumoperitoneal pressure on functions of liver and kidney in infant rabbits so as to provide rationales for clinical neonatal laparoscopy. Methods A total of 32 healthy young rabbits (3-week-old, 0.8-1.0 kg) were equally and randomly divided into control group (abdominal anesthesia only), operative group (abdomen anesthesia plus laparotomy) and 6 mmHg and 12 mmHg groups (abdominal anesthesia plus carbon dioxide pneumoperitoneum maintaining the pressures of 6 mmHg and 12 mmHg). And 10% chloral hydrate 3 ml/kg was injected into abdomen for anesthesia and 4% chloral hydrate 1ml for confirming the effect of anesthesia.Anesthetic time lasted for 4 hours.After closure, half of them were sacrificed and harvested venous blood, liver and kidney harvested.Half of rabbits in each group underwent anesthetic recovery and survived for 7 more days.Blood samples were collected before anesthesia (T0), 4 hours post-anesthesia (T1) and 7 days (T2). Tissues were fixed with 10% formalin and prepared into slices with hematoxylin & eosin (HE) staining for observations under optical microscope.The serum levels of alanine amino acid transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), glutamine transferase (GGT), creatinine (CR), urea nitrogen (BUN) and uric acid (UA) were detected. Results The serum levels of AST, TBIL, DBIL, CR, BUN and UA showed changes of no statistical significance at T0, T1 and T2 in four groups.The ALT levels at T1 and T2 in high pressure group were (81.24 U/L, 59.87 U/L) respectively and there was no significant inter-group difference (P>0.05). However, they were significantly higher than that at T0 (8.14 U/L)(P 0.05). However, they were significantly higher than those at T0(14.85 U/L)( P<0.05). Besides, as compared with ALT levels at T1 in control, open surgery and low pressure groups (20.310, 15.11, 15.980 U/L) and T2 (22.26, 14.70, 27.44 U/L), they were also significantly significant (P<0.05). HE staining showed diffuse liver congestion in high pressure group at 4 hours after anesthesia and showed no obvious improvement in 7 days.No obvious morphological change was seen in kidney. Conclusions Immature rabbits have an excellent tolerance for 6 mmHg and 12 mmHg pneumoperitoneal pressure.Kidney function has no obvious change in low pressure and high pressure groups.But 12 mmHg pneumoperitoneal pressure has greater effect on liver function.Diffuse liver congestion may be detected pathologically and there is no apparent improvement in 7 days. Key words: Pneumoperitoneum; Laboratory animal; Neonate; Liver function