Influence of laparoscopy and laparotomy on systemic and peritoneal T lymphocytes in a rat model

Evidence for the absence of visceral pain in C57BL6/N mice subjected to therapeutically relevant O3/O2-pneumoperitoneum

Each different gas that is used to induce a pneumoperitoneum (PP) exhibits individual effects within the peritoneal cavity. This might include adverse effects such as pain and/or inflammatory reactions. The acute effects of ozonized oxygen (O₃/O₂), a highly oxidative gas mixture, after being insufflated into the peritoneal cavity are analysed in this study. Using the abdominal constriction response ('writhing') assay of chemical nociception in C57BL6/N mice, O₃/O₂-PP was found not to be associated with visible pain responses and did not alter the c-fos expression in the spinal cord. In addition, mRNA expression levels of the pro-inflammatory cytokines, interleukin (IL)-1β and IL-6, were found unaltered in the spleen 2 h after insufflation. In conclusion, O₃/O₂-PP is free of adverse pain and does not trigger inflammatory immune responses.

Changes in T-lymphocytes' viability after laparoscopic versus open cholecystectomy

Laparoscopic surgery results in decreased immune and metabolic stress response compared to open surgery. Our aim was to evaluate the suspension of host immune defense in terms of apoptosis, necrosis, and survival of peripheral T-lymphocytes in patients undergoing laparoscopic versus open cholecystectomy. Apoptosis, necrosis and viability of peripheral T-lymphocytes were measured preoperatively and postoperatively by means of flow cytometry in 27 patients undergoing laparoscopic cholecystectomy and 25 undergoing open cholecystectomy. White cell count, CRP, and serum glucose levels were also measured. Viable peripheral T-lymphocytes were significantly decreased in open cholecystectomy (P = 0.02), while their late apoptotic as well as the overall necrotic rate were significantly increased (P = 0.01 and P < 0.01, respectively). Open cholecystectomy was also associated with lower levels of surviving circulating T-lymphocytes (P = 0.01) and higher percentage of necrotic T lymphocytes (P = 0.03) 24 hours postoperatively compared to laparoscopic cholecystectomy. Serum CRP was increased 24 hours after open cholecystectomy (P = 0.04). All differences failed to sustain more than 48 hours postoperatively. Increased viability and decreased necrosis of circulating T-lymphocytes were observed in laparoscopic cholecystectomy. Necrosis (and not apoptosis) seems to be the predominant pathway of T-lymphocyte death in open cholecystectomy, in a process reaching its peak at 24 hours and further attenuating 48 hours postoperatively.

Long-term survival outcomes of laparoscopic versus open gastrectomy for gastric cancer: a systematic review and meta-analysis

Many meta-analyses have confirmed the technical feasibility and favorable short-term surgical outcomes of laparoscopic gastrectomy (LG) for gastric cancer patients, but the long-term survival outcome of LG remains controversial compared with open gastrectomy (OG). This study aimed to compare the 5-year overall survival (OS), recurrence, and gastric cancer-related death of LG with OG among gastric cancer patients. PubMed was searched to February 2014. The resectable gastric cancer patients who underwent curative LG or OG were eligible. The studies that compared 5-year OS, recurrence, or gastric cancer-related death in the LG and OG groups were included. A meta-analysis, meta-regression, sensitivity analysis, subgroup analysis, and stage-specific analysis were performed to estimate the survival outcome between the two groups and identify the potential confounders. Quality assessment was based on a tailored comparability scoring system. Twenty-three studies with 7336 patients were included. The score of comparability between two groups and the extent of lymphadenectomy were two independent confounders. Based on the well-balanced studies, the 5-year OS (OR = 1.07, 95% CI 0.90-1.28, P = 0.45), recurrence (OR = 0.83, 95% CI 0.68-1.02, P = 0.08), and gastric cancer-related death (OR = 0.86, 95% CI 0.65-1.13, P = 0.28) rates were comparable in LG and OG. Several subsets such as the publication year, study region, sample size, gastrectomy pattern, extent of lymphadenectomy, number of nodes harvested, and proportion of T1-2 or N0-1 did not influence the estimates, if they were well balanced. Particularly, the stage-specific estimates obtained comparable results between the two groups. Randomized controlled trials comparing LG with OG remain sparse to assess their long-term survival outcomes. The major contributions of this systematic review compared with other meta-analyses are a comprehensive collection of available long-term survival outcomes within a much larger number of observations and a more precise consideration of confounders. Current knowledge indicates that the long-term survival outcome of laparoscopic gastric cancer surgery is comparable to that of open surgery among early or advanced stage gastric cancer patients, and LG is acceptable with regard to oncologic safety.

Short-term efficacy of laparoscopy-assisted vs open radical gastrectomy in gastric cancer

AIM: To investigate the short-term benefits of laparoscopic radical gastrectomy (LARG) and open radical gastrectomy (ORG) in patients with gastric cancer.

METHODS: A total of 400 patients with gastric cancer aged ≤ 65 years who were treated at General Hospital of Lanzhou Military Region were enrolled. Among these, 200 patients underwent LARG between October 2008 and August 2012 (LARG group); and 200 patients underwent ORG between March 2000 and September 2008 (ORG group). The short-term therapeutic benefits between the two groups were analyzed.

RESULTS: The LARG procedure offered significantly better benefits to the patients compared to the ORG procedure, including less intraoperative blood loss (103.1 ± 19.5 mL vs 163.0 ± 32.9 mL, P < 0.0001), shorter postoperative hospital stay (6.8 ± 1.2 d vs 9.5 ± 1.6 d, P < 0.0001), less frequent occurrence of postoperative complications (6.5% vs 13.5%, P = 0.02), shorter time to mobilization (1.0 ± 0.3 vs 3.3 ± 0.4 d, P < 0.0001), shorter time to bowel opening (3.3 ± 0.7 d vs 4.5 ± 0.7 d, P < 0.0001), and shorter time to normal diet (3.0 ± 0.4 vs d 3.8 ± 0.5 d, P < 0.0001). However, LARG required a longer time to complete than the ORG procedure (192.3 ± 20.9 min vs 180.0 ± 26.9 min, P < 0.0001).

CONCLUSION: Compared to ORG, LARG is safer, more effective, and less invasive for treating gastric cancer, with better short-term efficacy.

Comprehensive analysis of chemokines and cytokines secreted in the peritoneal cavity during laparotomy

We recently found that chemokine-driven peritoneal cell aggregation is the primary mechanism of postoperative adhesion in a mouse model. To investigate this in humans, paired samples of peritoneal lavage fluid were obtained from seven patients immediately after incision (preoperative) and before closure (postoperative), and were assayed for the presence of 27 cytokines and chemokines using multiplex beads assay. As a result, IL-6 and CCL5 showed the most striking increase during operation. Recombinant CCL5 or lavage fluid induced chemotaxis of human peripheral blood mononuclear cells. We propose that CCL5 is possibly involved in the mechanism of postoperative adhesion in humans.

Efficacy of a Lactococcus lactis ΔpyrG vaccine delivery platform expressing chromosomally integrated hly from Listeria monocytogenes

Listeria monocytogenes is a significant food-borne pathogen and the causative agent of listeriosis, a disease which manifests as meningitis in immunocompromised adults or infection of the fetus and miscarriage in pregnant women. We have previously used Lactococcus lactis, a GRAS (Generally Regarded As Safe) organism, as a vaccine vector against listeriosis by engineering plasmid-mediated expression of the immunodominant antigen from L. monocytogenes, listeriolysin O (LLO). However, the environmental release of an engineered vaccine vector carrying a replicating plasmid during clinical usage may raise safety concerns. Here we describe the integration of the LLO gene (hly) into the L. lactis chromosome through homologous double crossover to allow stable expression, in order to avoid the use of antibiotic selection markers and to eliminate the requirement for a plasmid-based system. The approach was designed to simultaneously eliminate the pyrG gene encoding the CTP synthase which is responsible for converting UTP to CTP in a unique step in the de novo pyrimidine synthesis in L. lactis. This gene was targeted in order to restrict bacterial replication outside of the host (biological containment). The resulting cytidine auxotroph was able to secrete LLO constitutively and could elicit LLO(91-99)-specific CD8(+) T lymphocytes in the murine infection model. Moreover, protection against lethal challenge with L. monocytogenes was accomplished after intraperitoneal (IP) vaccination with the constructed strain. The implications for the use of cytidine auxotropy in biological containment are discussed.

Abdominal emergencies: diagnostic and therapeutic laparoscopy

BACKGROUND

Laparoscopy has been practiced in the management of emergencies resulting from inflammatory conditions, lumenal obstruction, perforation, vascular occlusion, and trauma. This article identifies and discusses controversial areas in the field, in particular surrounding the efficacy, cost effectiveness, and perceived advantages of laparoscopy in the evaluation and treatment of patients with acute abdominal conditions.

MATERIALS AND METHODS

Review and commentary on pertinent articles in the English language literature are presented.

RESULTS

Prospective randomized trials have been reported in the treatment of some disorders, but a lack of recommendations that are evidence-based has hindered more widespread usage of laparoscopy in an emergency setting. In addition, concerns have been raised that the creation of capnoperitoneum in the patient with established peritonitis may be detrimental with respect to potentiation of bacteremia and severe sepsis, and experimental studies have yielded conflicting data in this regard.

CONCLUSION

As such issues are resolved, utilization of laparoscopy is likely to increase substantially as expertise is acquired. A minimal-access approach carries less morbidity and may offer other practical advantages in terms of surgical technique and application. When surgical intervention is appropriate, laparoscopy is now preferred for acute biliary disease. Female patients of reproductive age with acute appendicitis may benefit, particularly if there is preoperative diagnostic uncertainty. Selected cases of intestinal obstruction and visceral perforation presenting soon after symptom onset and in whom shock is absent may also be amenable to laparoscopic repair. Its use in the treatment of most trauma patients and patients with generalized peritonitis or hemodynamic instability is not recommended at present.

Urological laparoscopy: basic physiological considerations and immunological consequences

PURPOSE

The applications of laparoscopy to urological surgery continue to grow at a steady pace. A complete understanding of the physiological and immunological changes associated with pneumoperitoneum is required. We reviewed the physiology of laparoscopy with regard to the major organ systems and summarize the effects of pneumoperitoneum on immune function.

MATERIALS AND METHODS

Articles published in the scientific literature from 1990 to 2004 with relevance to laparoscopic physiology and the immune response to pneumoperitoneum were reviewed using PubMed.

RESULTS

Pneumoperitoneum induces predictable pulmonary and renal responses. The cardiovascular and hemodynamic responses are phasic and dynamic in nature, and only generalizations regarding cardiac function can be made. Renal parenchymal and venous compression during pneumoperitoneum are the etiology of oliguria during laparoscopy. The effects are reversible and cause no adverse effects on renal function. There is a general trend toward systemic immune preservation and peritoneal immune depression during insufflation based laparoscopy. Attenuated peritoneal immunity has been demonstrated most consistently by altered macrophage function.

CONCLUSIONS

Physiological changes incurred as a result of pneumoperitoneum have minimal adverse effects in healthy individuals undergoing laparoscopic surgery. Interest has grown in the impaired peritoneal immune response to CO2 pneumoperitoneum. Altered intraperitoneal immunity may represent a new avenue for the development of adjuvant therapies for minimally invasive treatments of urological malignancies and for the prevention of port site metastasis. Further elucidation and investigation into the immunological responses to pneumoperitoneum during urological laparoscopic procedures is called for.

Stress response to laparoscopic surgery: a review

BACKGROUND

Laparoscopic surgery is associated with reduced surgical trauma, and therefore with a less acute phase response, as compared with open surgery. Impairment of the immune system may enhance surgical infections, port-site metastases, and sepsis. The objectives of this review was to assess immunologic consequences of benign laparoscopic surgery and to highlight controversial aspects.

METHODS

A literature search on stress response to nonmalignant laparoscopic and open surgery was conducted using the MEDLINE and Cochrane databases. Cross-references from the reference list of major articles on the subject were used, as well as manuscripts published between 1993 and 2002.

RESULTS

Local (i.e., peritoneal) immune function is affected by carbon dioxide pneumoperitoneum. The production of tumor necrosis factor and the phagocytotic capacity of peritoneal macrophages are less lowered. The systemic stress response, as determined by delayed-type hypersensitivity response and leukocyte antigen expression on lymphocytes, shows a preservation of immune function after laparoscopic surgery, as compared with conventional surgery.

CONCLUSIONS

Intraperitoneal carbon dioxide insufflation attenuates peritoneal immunity, but laparoscopic surgery is associated with a lower systemic stress response than open surgery.

Repetitive pneumoperitoneum with ozonized oxygen as a preventive in lethal polymicrobial sepsis in rats

The aim of this study was to test whether repetitive pretreatments of rats with ozonized oxygen at relatively low gas volumes into the abdomen (20 ml per rat per day) have any beneficial or detrimental effects on the course of a polymicrobial-induced lethal peritonitis. Peritonitis was induced in a surgical or a nonsurgical model by usage of fecal material from the cecum. As the biological read out we used the mortality analysis. To include possible mechanisms by which ozone might influence the septic outcome, we characterized the gene expression of the pro-inflammatory cytokines IL-1beta, IL-2, and TNF-alpha mRNA in lymphoid organs. In both models, we found a significant beneficial influence of a dose-dependent O(2)/O(3 )pneumoperitoneum on the survival rate when compared to control animals or to room air. The ozone-enhanced survival seems to be independent from altered cytokine expression because there were no differences noticed in the levels of bacterial-induced gene expression of IL-1beta and TNF-alpha in septic animals pretreated with ozonized oxygen when compared to control animals.