Effects of laparotomy, and carbon dioxide and air pneumoperitoneum, on cellular immunity and peritoneal host defences in rats

Reoperation following minimally invasive surgery: are the "rules" different?

This article discusses various indications for reoperation and how employing laparoscopy at primary operation might affect the incidence, presentation, and treatment of common complications. The abdomen is likely to be far less hostile after laparoscopic surgery than after laparotomy. Adhesions to the anterior abdominal wall are minimal or absent. As a result, relaparoscopy is a reasonable diagnostic and often successful treatment modality in patients suspected of having intra-abdominal complications following laparoscopic operation. Laparoscopic success in dealing with acute bowel obstruction after laparoscopic surgery is related to the paucity of adhesions and unique mechanisms of obstruction that are localized and amenable to minimal dissection. The same mechanisms are also responsible for the increased risk of bowel necrosis associated with bowel obstruction after laparoscopic surgery. Limited experience with successful laparoscopic management of bleeding and anastomotic leak has been reported with the caveat that if the bleeding or contamination is excessive, cannot be identified and controlled quickly, or is unresponsive to a reasonable and brief effort using laparoscopy, a prompt laparotomy is indicated. Based on the current literature, it is reasonable to conclude that laparoscopic approaches to primary Crohn's disease and relaparoscopy for recurrence are an appropriate (perhaps the most appropriate) management strategy. Also, laparoscopic restorative proctocolectomy and ileal pouch-anal anastomosis after laparoscopic subtotal colectomy is the preferred treatment for toxic ulcerative colitis. We conclude that laparoscopic reoperative surgery is feasible for the treatment of many complications following laparoscopic major abdominal surgery and bowel resection.

Manipulation of the small intestine as a cause of the increased inflammatory response after open compared with laparoscopic surgery

BACKGROUND

Laparoscopic surgery of the gastrointestinal tract involves a reduced immune response compared with open surgery. The aim of this study was to assess manual handling of the gut in open procedures as the principal cause of the enhanced immune response.

METHODS

Eighteen Landrace pigs underwent gastrectomy by three different methods: conventional open wound with bowel manipulation, laparoscopically assisted gastrectomy, and gastrectomy without manipulation using a combination of open wound and laparoscopic surgical devices. Local inflammatory changes were assessed by ascites formation, intestinal adhesion development and intestinal inflammatory gene expression. Associated systemic inflammatory changes were determined by measuring portal and systemic plasma endotoxin levels, plasma inflammatory cytokine levels, liver inflammatory gene expression and transaminase levels.

RESULTS

Significantly more postoperative intra-abdominal fluid and adhesions were seen in the open group. The expression of inflammatory cytokines was significantly greater in the intestine and liver in the open group. Portal and systemic levels of endotoxin, inflammatory cytokines and transaminases were also higher.

CONCLUSION

Manual handling of organs during gastrectomy is an important contributor to the molecular and humoral inflammatory response to surgery, supporting the use of minimally invasive techniques in gastrointestinal surgery.

The effect of G-CSF in an experimental MRSA graft infection in mice

Wound infection after prosthetic material implantation is a troublesome complication with an incidence of 2% to 10%. The effect of granulocyte colony-stimulating factor (G-CSF) was studied in an experimental methicillin-resistant Staphylococcus aureus (MRSA) graft infection model. Eighty adult mice were used. Under general anesthesia an abdominal incision of 2 cm in length was performed. A subcutaneous cavity of 2 x 2 cm in size was created. Polypropylene mesh pieces of 2 x 1 cm and MRSA solution of 0.1ml of 10(8) CFU/mL were used. G-CSF was applied systemically or locally in a dosage of 0.02 MU/30 g body weight. There were 8 groups: group I, wound + MRSA; group II, wound + mesh + MRSA; group III, wound + mesh + MRSA + G-CSF (ip, 48 h before operation); group IV, wound + mesh + MRSA + G-CSF (ip, 24 h before operation); group V, wound + mesh + MRSA + G-CSF (locally, into the cavity); group VI, wound + mesh (incubated in G-CSF solution for 4 h) + MRSA; group VII, wound + mesh + MRSA + G-CSF, ip, 24 h from operation; and group VIII (positive control group), wound + mesh + MRSA + Teicoplanin (0.03 mg/30 g body weight, ip, 1/2 h before operation). Three days after, animals were killed and incisions were examined for possible infection or abscess formation and wound failure. Meshes were removed; after vortexing and dilution, samples were incubated with 5% agar media. Results of bacterial incubation were evaluated 24 h and 48 h later. There were symptoms of wound infection and abscess formation in all groups except group VIII. In group VIII, MRSA was isolated in 7 events with a colony count below 10(3). Bacterial counts were above 10(6) (10(6)-10(8)) in all other groups. Thus, it was observed that wound infection could be created with this model, but G-CSF could not prevent the development of wound infection, whether it was administered systemically or locally. Teicoplanin decreased the number of colony-forming units of MRSA, and prevents wound infection in this MRSA wound infection model.

Staged abdominal repair for treatment of moderate to severe secondary peritonitis

The aim of this study was to evaluate the effects of planned relaparotomy and to assess factors that may contribute to mortality in patients with moderate to severe secondary peritonitis. A total of 36 consecutive patients with an Acute Physiologic and Clinical Health Evaluation (APACHE) II score of >10 were enrolled the study for a 2-year period. The mean age of the patients was 56 years (17-92 years), and 23% of them were male. One-third of them had postoperative peritonitis; 152 scheduled operations were done, and the overall mortality rate was 36%. For patients whose septic source was in the upper gastrointestinal system, control of the source was more difficult (p = 0.004). Overall, 28 complications developed in 61% of the patients. Initial and second-day APACHE II scores were 14.5 (11-27) and 12.0 (9-25), respectively. The initial APACHE II score of survivors was lower than that of nonsurvivors [p = 0.0001, 95% confidence interval (CI) -9.5, -3.6]. Second-day APACHE II scores were not different (p = 0.19; 95% CI -3.79, 0.80). Striking end or lateral duodenal leaks were clearly associated with high mortality. It is found that the initial APACHE II score, the success of controlling the source, the occurrence of complications, and the type of illness are independent factors that may affect mortality. We concluded that staged abdominal repair should be used with caution in the treatment of lateral or end duodenal leaks. It is a good alternative to conventional laparotomy for moderate to severe forms of secondary peritonitis from other sources.

Immunologic changes during minimally invasive surgery

Although recent experimental and clinical trials have documented that postoperative inflammation and changes in different immunologic parameters are less pronounced after laparoscopic approaches in comparison to open surgery, it still remains unclear what influence the pneumoperitoneum itself has on immunologic defense and function. This is mainly due to the endpoints of the different studies which investigate changes in the so-called immunologic parameters (cell subunits, C-reactive protein, cytokines, catecholamines or other stress hormones in plasma samples) rather than analyzing immunologic functions, such as cell activation, production of proteins, cell proliferation or in vivo immune defenses. So far, especially in clinical trials, no correlation has been demonstrated between the changes in immunologic parameters and relevant postoperative clinical endpoints, such as postoperative complications. Thus further clinical prospective randomized studies with relevant clinical endpoints and additional investigations of immunologic parameters are needed to prove the consequences of either minimally invasive surgery or open procedures on postoperative immune functions.

Lavage by laparoscopy fares better than lavage by laparotomy: experimental evidence

BACKGROUND

Although carbon dioxide (CO2) pneumoperitoneum is proposed increasingly for treatment of secondary peritonitis, associated deleterious effects have been reported in experimental models, with the hypothesis that increased intraperitoneal pressure might facilitate bacterial translocation. The purpose of this study was to compare the outcome (and qualitative microbiologic analysis) from peritonitis in rats after lavage by laparoscopy with the outcome after lavage by laparotomy.

METHODS

After determination of the standard innoculum for this study in 30 animals, 120 male Wistar rats received 1 ml of Escherichi coli 10(6) colony-forming unit (CFU), Bacteroides fragilis 10(7) CFU, Enterococcus faecalis 10(7) CFU in a sterile rat feces-barium sulfate suspension adjuvant, were anesthetized with intramuscular ketamine, and then underwent peritoneal lavage by either laparotomy (n = 60) or laparoscopy (n = 60). The duration of peritonitis defined two groups: group A: duration less than 3 h (n = 20) and group B: duration 3 h or more (n = 40). Both groups underwent successive lavage with 10-ml aliquots (total, 50 ml) of 0.9% saline solution at 37 degrees C. Five 2-ml samples of liquid lavage were drawn for culture and microbiologic analysis. Blood (0.2 ml) and peritoneal liquid lavage samples were incubated 48 h at 37 degrees C and cultured.

RESULTS

All the animals survived. Mean duration of peritoneal lavage was 13.2 min (range, 6-25 min) for laparoscopy and 9.7 min (range, 6-15 min) and for laparotomy. The difference was not statistically significant. The mean duration of operation was significantly longer with laparoscopy than with laparotomy: 44.5 min (range, 35-62 min) and 25 min (range, 16-40 min), respectively (p = 0.0001). The collected lavage volumes were not statistically different: 48.5 ml (range, 40-54 ml) and 46.7 ml (range, 37-56 ml), respectively. No statistically significant differences were found between the laparoscopy and laparotomy groups in terms of E. coli bacteremia, irrespective of peritonitis duration. The rates of positive blood culture for B. fragilis and E. faecalis were signficantly lower after laparoscopy than after laparotomy, both in the overall group (p = 0.025 and p = 0.045, respectively) and when duration of peritonitis exceeded 3 h (p = 0.001 and p = 0.044, respectively).

CONCLUSIONS

In this animal model of secondary peritonitis, lavage by laparoscopy was associated with less bacteremia for B. fragilis and E. faecalis than peritoneal lavage by laparotomy.

Intraperitoneal macrophages and tumor immunity: A review

The macrophage (Mphi) is considered the first line of defense in immune response to foreign invaders. Increasing evidence suggests that Mphi(s) also play an important role against neoplastic cells. Mphi(s) exposed to supraphysiologic concentrations of CO(2) are suppressed. As surgeons apply newer minimally invasive techniques to oncologic therapies, it is important to evaluate the impact of these techniques on host-tumor interactions. We review the current understanding of Mphi biology with specific attention on cytotoxicity in addition to tumor immunity. Although systemic immune function is better preserved after laparoscopy than laparotomy, peritoneal Mphi(s) show reduced function after CO(2) pneumoperitoneum than exposure to air. Mphi(s) have shown cytotoxicity to syngeneic cancer cells and may play an important role in tumor surveillance. The impairment in Mphi function after CO(2) exposure may have an effect on outcome after oncologic surgery. In our understanding, Mphi(s) help destroy neoplastic cells. As CO(2) impairs Mphi activity, laparoscopy may significantly alter the host-tumor interaction.

Effects of CO2 insufflation and laparotomy on wound healing in mice

BACKGROUND

The aim of the present study was to evaluate the effects of laparotomy and CO2 insufflation on wound healing in a murine incisional wound healing model.

METHODS

Seventy-two male Swiss Albino mice were randomly allocated into three groups of control, laparotomy and CO2 insufflation. A transverse skin incision of 15 mm was made in the dorsum of each mouse, and four interrupted mattress sutures with 4.0 polypropylene thread were laid for wound closure. A median laparotomy was performed in the laparotomy group. CO2 insufflation was performed with an intra-abdominal pressure of 9 mmHg. The retained gas was evacuated from the abdominal cavity at the end of a 60-min period. Mice were killed on the 3rd, 7th and 15th postoperative days. The wound tensile strength and 5-hydroxyproline concentration in the wound tissue were measured.

RESULTS

Tensile strength of the incised skin increased as the post-incision period progressed. There was no significant difference between the tensile strengths of the incised skin of control, laparotomy and CO2 insufflation groups throughout the observation period. The skin 5-hydroxyproline concentrations of all groups were not significantly different at the 3rd postoperative day. But laparotomy and CO2 insufflation groups had lower 5-hydroxyproline concentrations at the 7th and 15th postoperative days, when compared to controls (P < 0.02 for 7th and 15th days).

CONCLUSION

CO2 insufflation and laparotomy reduce the 5-hydroxyproline concentration of the wound, suggesting a diminished wound healing capacity.