Immunologic postoperative competence after laparoscopy versus laparotomy

Effects of different anesthesia methods on postoperative immune function in patients undergoing gastrointestinal tumor resection

To investigate the effects of different anesthetic methods on postoperative immune function in patients undergoing gastrointestinal tumor resection. Ninety patients undergoing laparoscopic gastrointestinal tumor resection were divided into 3 groups. Patients in the GA group were anesthetized by total intravenous anesthesia. The GE group was anesthetized by general anesthesia combined with epidural anesthesia. The GN group was anesthetized by general anesthesia combined with bilateral Transversus Abdominis Plane block (TAP) and rectus sheath nerve blocks. General anesthesia is total intravenous anesthesia in all three groups. Blood samples were taken to test the changes of peripheral lymphocyte subtype analysis, and levels of plasma cortisol, epinephrine, norepinephrine. Also, the dosage of anesthetic drugs, recovery time, and visual analog scale (VAS) scores were recorded. Postoperative immune indexes, including CD4 count, CD8 count, B, and NK cells, in the GE group were significantly higher than those in NA and GA groups (P < 0.01). Perioperative stress indices, including epinephrine levels, norepinephrine level and aldosterone level, in the GE group were significantly lower than in the GA group and GN group (P < 0.01). The intraoperative/total sufentanil dosage and remifentanil dosage in the GE group were significantly lower than those in the GA and GN groups (P < 0.01). The VAS scores in the GE group were significantly better than those in GA and GN groups (P < 0.01). General anesthesia combined with epidural anesthesia attenuates the increase in inflammatory mediators. Its possible mechanisms include reducing perioperative stress response and reducing perioperative opioid use.

A comparison of the oxidative stress response in single-incision laparoscopic versus multi-trocar laparoscopic totally extraperitoneal inguinal hernia repair

Introduction

Surgical treatment is always associated with tissue damage and the subsequent development of oxidative stress.

Aim

To compare the oxidative stress response in patients treated operatively for inguinal hernia with multi-trocar laparoscopic totally extraperitoneal technique (TEP) or single-incision laparoscopic totally extraperitoneal technique (TEP-SI).

Material and methods

A randomized group of 34 patients with one-sided inguinal hernia was enrolled in the study. Seventeen patients were treated with a standard TEP method (group 1) and the other 17 patients were treated with the TEP-SI technique (group 2). Thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAS) as the oxidative stress markers were measured before surgery (0), 1 day (1) and 4 days (2) after surgery.

Results

A decrease in TAS on the first day after surgery was observed in both groups. Sustained reduction on the fourth day after surgery was observed in group 1, whereas in group 2 an increase followed. A statistically significant difference was observed in TAS (2 : 0) ratio with a meaningful decrease in group 1. TBARS concentration was elevated 1 day after surgery in both groups. It remained at an elevated level on the fourth day after surgery in group 1, while it decreased in group 2. The duration of surgery was higher in group 2 (mean: 57.5 min) than in group 1 (mean: 50.0 min) (p = 0.0286).

Conclusions

Oxidative stress levels are lower in patients treated operatively by TEP-SI technique than by TEP. TEP-SI may be considered as a less invasive technique associated with less tissue injury.

Postoperative lymphopenia: An independent risk factor for postoperative pneumonia after lung cancer surgery, results of a case-control study

Objective

Postoperative lymphopenia has been proposed as a risk factor for postoperative infections but has never been identified as such in a multivariate analysis. Postoperative pneumonia (POP) is one of the most common complications after lung cancer surgery and is associated with a worse outcome. We aimed to evaluate the association between postoperative lymphopenia and POP after lung cancer surgery.

Methods

Patients admitted for lung cancer surgery (lobectomy, bilobectomy, or pneumonectomy) aged ≥ 18 years and with no history of an immunosuppressive state were eligible for inclusion. Lymphocyte counts were determined in blood drawn on the day before surgery and at postoperative days 1, 3 and 7. POP diagnosis was based on clinical, biological and radiological data. A logistic regression model adjusted on currently described risk factors for POP was used to explain the onset of this condition.

Results

Two hundred patients were included, of whom 43 (21.5%) developed POP. Preoperative lymphocyte count was 1.8±0.6x10⁹ cells/L and 2.0±0.7x10⁹ cells/L in patients with and without POP, respectively (P = .091). In both groups, the lymphocyte count nadir occurred at postoperative day 1. In multivariate analysis, lymphopenia at postoperative day 1 was significantly associated with increased risk of POP (odds ratio: 2.63, 95% CI [1.03–5.40]). POP rate at postoperative day 7 was higher in patients presenting low lymphocyte counts (≤1.19x10⁹ cells/L) at postoperative day 1 (P = .003).

Conclusions

Our study showed that lymphopenia following lung cancer surgery was maximal at postoperative day 1 and was associated with POP.

Transrectal rigid-hybrid NOTES cholecystectomy can be performed without peritoneal contamination: a controlled porcine survival study

BACKGROUND AND STUDY AIMS

The risk of infectious complications due to peritoneal contamination is a major concern and inhibits the widespread use of transrectal NOTES. A standardized rectal washout with a reversible colon occlusion device in situ has previously shown potential in reducing peritoneal contamination. The aim of this study was to compare the peritoneal contamination rate and inflammatory reaction for transrectal cholecystectomy after ideal rectal preparation (trCCE) and standard laparoscopic cholecystectomy (lapCCE) in a porcine survival experiment.

METHODS

Twenty pigs were randomized to trCCE (n = 10) or lapCCE (n = 10). Before trCCE, rectal washout was performed with saline solution. A colon occlusion device was then inserted and a second washout with povidone-iodine was performed. The perioperative course and the inflammatory reaction (leukocytes, C-reactive protein) were compared. At necropsy, 14 days after surgery the abdominal cavity was screened for infectious complications and peritoneal swabs were obtained for comparison of peritoneal contamination.

RESULTS

Peritoneal contamination was lower after trCCE than after lapCCE (0/10 vs. 6/10; p = 0.003). No infectious complications were found at necropsy in either group and postoperative complications did not differ (p = 1.0). Immediately after the procedure, leukocytes were higher after lapCCE (17.0 ± 2.7 vs. 14.6 ± 2.3; p = 0.047). Leukocytes and C-reactive protein showed no difference in the further postoperative course. Intraoperative complications and total operation time (trCCE 114 ± 32 vs. 111 ± 27 min; p = 0.921) did not differ, but wound closure took longer for trCCE (31.5 ± 19 vs. 13 ± 5 min; p = 0.002).

CONCLUSIONS

After standardized rectal washout with a colon occlusion device in situ, trCCE was associated without peritoneal contamination and without access-related infectious complications. Based on the findings of this study, a randomized controlled clinical study comparing clinical outcomes of trCCE with lapCCE should be conducted.

Gut barrier function and systemic endotoxemia after laparotomy or laparoscopic resection for colon cancer: A prospective randomized study

PURPOSE:

The gut barrier is altered in certain pathologic conditions (shock, trauma, or surgical stress), resulting in bacterial and/or endotoxin translocation from the gut lumen into the systemic circulation. In this prospective randomized study, we investigated the effect of surgery on intestinal permeability (IP) and endotoxemia in patients undergoing elective colectomy for colon cancer by comparing the laparoscopic with the open approach.

PATIENTS AND METHODS:

A hundred twenty-three consecutive patients underwent colectomy for colon cancer: 61 cases were open resection (OR) and 62 cases were laparoscopic resection (LR). IP was measured preoperatively and at days 1 and 3 after surgery. Serial venous blood sample were taken at 0, 30, 60, 90, 120, and 180 min, and at 12, 24, and 48 h after surgery for endotoxin measurement.

RESULTS:

IP was significantly increased in the open and closed group at day 1 compared with the preoperative level (P < 0.05), but no difference was found between laparoscopic and open surgery group. The concentration endotoxin systemic increased significantly in the both groups during the course of surgery and returned to baseline levels at the second day. No difference was found between laparoscopic and open surgery. A significant correlation was observed between the maximum systemic endotoxin concentration and IP measured at day 1 in the open group and in the laparoscopic group.

CONCLUSION:

An increase in IP, and systemic endotoxemia were observed during the open and laparoscopic resection for colon cancer, without significant statistically difference between the two groups.

Prognostic value of perioperative leukocyte count in resectable gastric cancer

AIM: To investigate the prognostic significance of perioperative leukopenia in patients with resected gastric cancer.

METHODS: A total of 614 eligible gastric cancer patients who underwent curative D2 gastrectomy and adjuvant chemotherapy were enrolled in this study. The relationship between pre- and postoperative hematologic parameters and overall survival was assessed statistically, adjusted for known prognostic factors.

RESULTS: The mean white blood cell count (WBC) significantly decreased after surgery, and 107/614 (17.4%) patients developed p-leukopenia, which was defined as a preoperative WBC ≥ 4.0 × 10⁹/L and postoperative WBC < 4.0 × 10⁹/L, with an absolute decrease ≥ 0.5 × 10⁹/L. The neutrophil count decreased significantly more than the lymphocyte count. P-leukopenia significantly correlated with poor tumor differentiation and preoperative WBC. A higher preoperative WBC and p-leukopenia were independent negative prognostic factors for survival [hazard ratio (HR) = 1.602, 95% confidence interval (CI): 1.185-2.165; P = 0.002, and HR = 1.478, 95%CI: 1.149-1.902; P = 0.002, respectively] after adjusting for histology, Borrmann type, pTNM stage, vascular or neural invasion, gastrectomy method, resection margins, chemotherapy regimens, and preoperative WBC count. The patients with both higher preoperative WBC and p-leukopenia had a worse prognosis compared to those with lower baseline WBC and no p-leukopenia (27.5 mo vs 57.3 mo, P < 0.001).

CONCLUSION: Preoperative leukocytosis alone or in combination with postoperative leukopenia could be independent prognostic factors for survival in patients with resectable gastric cancer.

Laparoscopically assisted colorectal surgery provides better short-term clinical and inflammatory outcomes compared to open colorectal surgery

INTRODUCTION

Changes in immune function after surgery may influence overall outcome, length of hospital stay, susceptibility to infection and perioperative tumour dissemination in cancer patients. Our aim was to elaborate on postoperative differences in the immune status and the intensity of the systemic inflammatory response between two groups of prospectively enrolled patients with colorectal cancer, namely patients undergoing laparoscopically assisted or open colorectal surgery.

MATERIAL AND METHODS

Blood samples from 77 patients were taken before surgery and then 3 h, 24 h and 4 days after surgery. The inflammatory response was determined by leukocyte counts, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin levels (PCT). Immune status was determined by phenotypic analysis of lymphocyte populations and the activation of mononuclear cells. CD64 expression and cytokine expression were also determined.

RESULTS

Patients undergoing laparoscopically assisted surgery had less intraoperative blood loss (p = 0.002), earlier resumption of diet (p = 0.002) and shorter hospital stay (p = 0.02). Numbers of total leukocytes (p = 0.12), CRP (p = 0.002) and PCT (p = 0.23) were remarkably higher 4 days after surgery in patients who underwent an open colorectal procedure. There was an important decrease in monocyte HLA-DR expression 3 h after surgery in patients undergoing laparoscopically assisted surgery (p = 0.03).

CONCLUSIONS

Our study suggests that minimally invasive surgery provides better short-term clinical outcomes for patients with resectable colorectal cancer. The acute inflammatory response is less pronounced. Post-surgical immunological disturbance in both groups is similar, but we observed a divergent effect of different surgical approaches on the expression of HLA-DR on monocytes. However, our results corroborate the results of previous studies.

Recovery of immunological homeostasis positively correlates both with early stages of right-colorectal cancer and laparoscopic surgery

Differences in postoperative outcome and recovery between patients subjected to laparoscopic-assisted versus open surgery for colorectal cancer (CRC) resection have been widely documented, though not specifically for right-sided tumors. We investigated the immunological responses to the different surgical approaches, by comparing postoperative data simultaneously obtained at systemic, local and cellular levels. A total of 25 right-sided CRC patients and controls were managed, assessing -in the immediate followup- the conventional perioperative parameters and a large panel of cytokines on plasma, peritoneal fluids and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) tissue cultures. A general better recovery for patients operated with laparoscopy compared to conventional procedure, as indicated by the analysis of typical pre- and post-surgical parameters, was observed. The synchronous evaluation of 12 cytokines showed that preoperative plasma levels of the proinflammatory cytokines IL-6, IL-8, IL-1β, TNFα were significantly lower in healthy donors versus CRC patients and that such differences progressively increase with tumor stage. After surgery, the IL-6 and IL-8 increases were significantly higher in open compared to laparoscopic approach only in CRC at early stages. The postsurgical whole panel of cytokine levels were significantly higher in peritoneal fluids compared to corresponding plasma, but with no significant differences depending on kind of surgery or stage of disease. Then we observed that, pre- compared to the corresponding post-surgery derived LPS-stimulated PBMC cultures, produced higher supernatant levels of the whole cytokine panel. In particular IL-6 in vitro production was significantly higher in PBMC derived from patients subjected to laparoscopic versus open intervention, but -again- only in CRC at early stages of disease. Our results thus show that laparoscopy compared to open right resection is associated with a shorter compromission of the immunological homeostasis, mainly in early stages of right-CRC patients.

Evaluation of lymphocytes CD4+ and CD8+ and expression of ZAP-70 kinase on CD3+ and CD19+ lymphocytes in obese patients undergoing laparoscopic cholecystectomy

Background

Obesity has become a global epidemic and a leading metabolic disease in the world. Laparoscopic surgeries may influence the function of the immunologic system. The percentages of CD4+ and CD8+ T lymphocyte cells have been described as prognostic factors for patients undergoing abdominal surgeries. This study aimed to evaluate the changes in CD4+ and CD8+ T lymphocyte cells, the ratio of CD4+ to CD8+ cells, and the ZAP-70 kinase expression on T CD3+ and B CD19+ cells in obese and normal-weight individuals undergoing laparoscopic cholecystectomy (LC).

Methods

The study group consisted of 46 asymptomatic patients with gallstones shown by ultrasound examination but without signs of any gallbladder complications. The patients underwent planned LC. Blood samples were obtained at three times, and the percentages of studied cells were measured by flow cytometry. Patients were enrolled to two groups: N group (body mass index [BMI], ≤25 kg/m²) and O group (BMI, ≥30 kg/m²). For statistical analysis, the Mann–Whitney U test and the Wilcoxon matched-pairs signed-ranks test were used. All p values lower than 0.05 were considered significant.

Results

The percentage of CD4+ T cells did not differ between the N and O groups before or after the surgery. Only in the N group did the percentage of CD4+ lymphocytes increase from 0 to 48 h. A higher percentage of CD8+ lymphocytes was observed in the O group postoperatively than in the N group. Differences of ZAP-70 kinase expression in the O group were observed at 24 and 48 h of the study. Decreased expression of ZAP-70 kinase was shown in the N group at both 0–24 and 24–48 h. In the O group, this tendency was noted at 24–48 h.

Conclusions

Immunologic activation after LC was confirmed in both weight groups. However, higher modulation, more typical for open surgeries, was observed in the obese group.

Systemic inflammatory response after laparoscopic and conventional colectomy for cancer: a matched case-control study

BACKGROUND

Studies dealing with laparoscopic colectomy for cancer have reached conflicting results in regards to various inflammatory cytokines. Most of them have not examined potential differences with the open procedures at later postoperative days, when the immunologic advantage of laparoscopic surgery would be more demanding to demonstrate (for earlier administration of adjuvant treatment). The aim of this work is to detect differences of proinflammatory cytokines between conventional and laparoscopic colectomy for cancer.

PATIENTS AND METHODS

30 patients who underwent laparoscopic colectomy were age, sex, and preoperative stage-matched with 30 patients treated by open surgery. C-reactive protein (CRP), interleukin (IL)-1, -6, and -8, and interferon (IFN)-γ serum levels were measured preoperatively, at 24 h, and at the 7th postoperative day (POD).

RESULTS

CRP and IL-6 postoperative values (24 h and 7th POD) were significantly higher than baseline for both groups (p = 0.001), but the respective values at the 7th POD were less than at 24 h (p = 0.001). IL-1 and -8 levels did not show any differences between assessment timepoints. A higher IFN-γ measurement was demonstrated at 24 h compared with baseline for the laparoscopic group only (p = 0.03). This difference was not maintained at the 7th POD. IFN-γ levels at 24 h and the 7th POD were significantly less for the open compared with the laparoscopic group of patients (p = 0.001). No correlation was revealed between measured serum values and age, sex, tumor location, or stage.

CONCLUSIONS

This matched case-control study verifies the already reported lack of differences regarding IL-1. Controversy still exists on likely IL-6 differences. The inadequately studied IL-8 does not seem to play an important role in immunologic differences. The immunologically beneficial IFN-γ, produced by the principal effectors of cell-mediated immunity Th1 cells, seems to have a more active presence following laparoscopic colectomy, potentially contributing to an immunologic "advantage" by counteracting "harmful" cytokines, such as IL-1.

Comparative evaluation of surgical stress of laparoscopically assisted vaginal radical hysterectomy and lymphadenectomy and laparotomy for early-stage cervical cancer

The aim of this study was to objectively evaluate the benefits of laparoscopically assisted vaginal radical hysterectomy and lymphadenectomy for early-stage cervical cancer. Clinical data were prospectively collected from patients with IA-IIB cervical cancer who underwent laparoscopically assisted vaginal radical hysterectomy (n1=33) and laparotomy (n2=30). Peripheral blood samples were obtained prior to surgery and at 1 and 2 h into the operation, as well as on days 1, 4 and 7 following surgery to measure serum interleukin-6, C-reaction protein and cortisol. Results showed that there was no conversion to laparotomy in the laparoscopy group. The average blood loss was 317.23±217.20 ml (laparoscopy group) and 872.58±693.16 ml (laparotomy group). No significant difference was found in the number of resected pelvic lymph nodes (19.74±7.43 in the laparoscopy group and 20.35±6.62 in the laparotomy group). At days 1 and 7 after surgery, the serum IL-6 level was significantly different in the laparoscopy and laparotomy groups (day 1: laparoscopy group 17.14±16.53 pg/ml and laparotomy group 34.32±20.97 pg/ml, p=0.001; day 7: laparoscopy group 6.7±7.21 pg/ml and laparotomy group 17.54±16.47 pg/ml, p=0.001). The serum CRP level was significantly different at days 1 and 7 after the operation (day 1: laparoscopy group 7024.72±949.12 ng/ml and laparotomy group 7586.61±869.42 ng/ml, p=0.018; day 7: laparoscopy group 4357.71±2108.85 ng/ml and laparotomy group 6967.96±995.02 ng/ml, p<0.001). A significant difference was noted in the serum cortisol level at day 4 after the operation (122.29±65.17 ng/ml in the laparoscopy group and 186.76±68.61 ng/ml in the laparotomy group, p<0.001). In conclusion, the differences in clinical data and the various parameters pertinent to surgical stress evaluated in this study suggest that laparoscopic surgery for cervical cancer causes less postoperative stress than conventional open surgery.

Immunological effects of laparoscopic and open cholecystectomy

This prospective, randomized, controlled study evaluated plasma levels of interleukin-18 (IL-18) and monocyte chemotactic protein-1 (MCP-l) in patients undergoing cholecystectomy. Forty patients were randomized to undergo laparoscopic cholecystectomy (LC) or open cholecystectomy (OC). Plasma concentrations of IL-18 and MCP-1 were measured before anaesthesia (T(0)), before operation (T(1)), 30 min after the start of the operation (T(2)) and at the end of the operation (T(3)). Compared with T(0), the IL-18 concentration was significantly increased at T(2) and T(3) in both groups. In addition, the MCP-1 concentration was significantly increased at T(3) compared with T(0) in the LC group. Both the IL-18 and MCP-1 concentrations were significantly lower in the OC group than in the LC group at T(3). It is suggested that carbon dioxide pneumoperitoneum may cause immunodepression, that epidural anaesthesia can attenuate the stress response, and that IL-18 and MCP-1 are sensitive markers for evaluating the patient's immune function.

The difference of the impacts of surgical approaches on cellular immunity in patients with uterine malignancies: a comparative study of laparoscopy and laparotomy surgery

OBJECTIVE

To explore the impact of laparoscopy and laparotomy surgery on cellular immunity in patients with malignant uterine tumors.

METHODS

Thirty-eight women with uterine malignancies were enrolled in a prospective nonrandomized cohort study. Either laparoscopy or laparotomy was performed according to the patients' choice. The frequency of CD3+, CD4+, CD8+ T cells and natural killer cells derived from peripheral venous blood was evaluated by flow cytometry.

RESULTS

(1) Postoperatively, there was a decrease in the number of lymphocyte counts, especially after laparotomy, on the first postoperative day (p < 0.01). (2) Compared with preoperative levels, the frequencies of CD3+ and CD4+ cells and the CD4+/CD8+ ratio were declined both in the laparoscopy and laparotomy groups on postoperative day 1 (p < 0.01). (3) The frequencies of CD3+ and CD4+ cells and the ratio of CD4+ to CD8+ cells were less depressed in the laparoscopy group on the first postoperative day (p < 0.05). (4) The frequency of natural killer cells increased, both in the laparoscopy and laparotomy groups on the first postoperative day (p < 0.01), but there were no significant differences between the two groups (p > 0.05).

CONCLUSION

Cellular immunity was temporally depressed in patients with uterine malignancy after surgical treatment, but laparoscopic surgery depressed the immunity less than laparotomy.

Immunologic and oncologic implications of laparoscopic surgery: what is the latest?

Laparoscopic surgery has been associated with many short-term benefits such as a shorter time to recovery, return of bowel function, less pain, and a decrease in wound infection rate. Several animal and human experiments have demonstrated an immunologic and oncologic benefit of minimally invasive surgery. Whether these results will translate into similar results in human settings is unclear. Although the first published prospective randomized clinical trial suggests better long-term outcomes for patients undergoing laparoscopic surgery, results from other ongoing randomized, controlled clinical trials are needed to verify this controversial result.

A phase I trial of oxaliplatin for intraperitoneal hyperthermic chemoperfusion for the treatment of peritoneal surface dissemination from colorectal and appendiceal cancers

BACKGROUND

Cytoreductive surgery with intraperitoneal hyperthermic chemoperfusion (IPHC) has evolved into a promising approach for peritoneal surface malignancy. A large body of literature suggests that oxaliplatin has excellent cytotoxicity against colorectal cancer. Therefore, we undertook a phase I evaluation of IPHC with oxaliplatin for peritoneal dissemination from colorectal and appendiceal cancers to establish the dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD).

METHODS

Cohorts of three patients underwent cytoreductive surgery followed by a 2-h IPHC with escalating doses of oxaliplatin at a target outflow temperature of 40 degrees C. The initial peritoneal oxaliplatin dose was 200 mg/M(2) with increases planned in 50 mg/M(2 )increments. Plasma and perfusate samples were collected during the IPHC and evaluated using emission spectrometry techniques. Normal tissue and tumor samples were collected before and after the IPHC for analysis. DLT was defined as a grade 3 toxicity lasting 5 days.

RESULTS

Fifteen patients were enrolled at two dose levels. Peritoneal fluid areas under the curve (AUCs) were above those of plasma. Additionally, intratumoral oxaliplatin was similar to that of surrounding normal tissue. Dose-limiting toxicities at 250 mg/M(2 )were observed in two of three patients enrolled in this study.

CONCLUSION

We found that IPHC with 200 mg/M(2 )of oxaliplatin is well tolerated and is the MTD for a 2-h chemoperfusion. Higher doses are not feasible with this perfusion protocol given the significant toxicities associated with 250 mg/M(2 )oxaliplatin. Based on the data from this phase I study, we propose to conduct further studies with oxaliplatin delivered at 200 mg/M(2).

Perioperative cyclooxygenase 2 inhibition to reduce tumor cell adhesion and metastatic potential of circulating tumor cells in non-small cell lung cancer

OBJECTIVE

Surgical manipulation of lung cancers may increase circulating tumor cells and contribute to metastatic recurrence after resection. Cyclooxygenase 2 is overexpressed in most non-small cell lung cancer and upregulates the cell adhesion receptor CD44. Our goal was to examine the effects of perioperative cyclooxygenase blockade on the metastatic potential of circulating tumor cells, CD44 expression, and adhesion of cancer cells to extracellular matrix.

METHODS

Human non-small cell lung cancer cells (A549) were injected through the lateral tail vein in an in vivo murine model of tumor metastasis with three random treatment groups: no treatment, perioperative selective cyclooxygenase 2 inhibition (celecoxib) only, and continuous celecoxib. Lung metastases were assessed at 6 weeks by a blinded observer. For in vitro experiments, cells were treated with celecoxib, and expression of CD44 was determined by Western blotting. Extracellular matrix adhesion was assessed by Matrigel (BD Labware, Bedford, Mass) assay.

RESULTS

In vivo lung metastases were significantly decreased relative to control by both perioperative and continuous celecoxib (P = .0135). There was no significant difference in number of metastases between continuous and perioperative treatment groups. In vitro adhesion to the extracellular matrix was significantly inhibited by celecoxib in a dose-dependent manner (P < .01). A549 cells expressed high levels of CD44, upregulated by interleukin 1beta and downregulated by celecoxib.

CONCLUSION

Celecoxib significantly reduced establishment of metastases by circulating tumor cells in a murine model. It also inhibited CD44 expression and extracellular matrix adhesion in vitro. Perioperative modulation of cyclooxygenase 2 may be a novel strategy to minimize metastases from circulating tumor cells during this high-risk period.

Immunological advantages of advanced laparoscopy

Surgical trauma causes significant alterations in host immune function. Compared with open surgery, laparoscopic surgery is associated with reduced postoperative pain and more rapid return to normal activity. Experimental data have also shown more aggressive tumor establishment and growth rates following open surgery and laparoscopic surgery. Surgery-related immunosuppression may be partly responsible for the differences in cancer growth and outcome noted. It is clear that the choice of abdominal surgical approach has immunologic consequences. Further studies are needed to better the time course and extent of surgery-related alterations in the immune system and their clinical importance. A better understanding of the impact of surgery on the immune system may provide opportunities for pharmacologic manipulation of postoperative immune function to improve clinical results.