Laparoscopy vs minilaparotomy and full laparotomy preserves circulatory but not peritoneal and pulmonary immune responses

The Length of Surgical Skin Incision in Postoperative Inflammatory Reaction

Background and Objectives:

Surgery provokes inflammatory and immune responses, so efforts have been made to reduce host response by using less invasive techniques. The purpose of this experimental study was to investigate the surgical stress induced by skin incision and the role of liver response in this process.

Methods:

Seventy male anesthetized Wistar rats were subjected to a midline incision confined strictly to the skin (dermis) of either 1 cm long (n = 20), 10 cm long (n = 20), or no incision (n = 20) or served as controls (n = 10). Skin trauma was left open for a 20-minutes period, and then was meticulously sutured. At 3 and 24 hours later, laparotomy was performed on half the rats of each group, for blood and liver sampling. In serum and liver homogenates, cytokine-induced neutrophil chemoattractant (CINC)1/interleukin (IL)-8 and tumor necrosis factor (TNF)-α levels were measured with enzyme-linked immunosorbent assays and nitric oxide (NO) using a Griess reaction.

Results:

Skin trauma was found to significantly (P < .01) increase all inflammatory mediators tested (CINC1/IL-8, TNF-α, NO) in serum of operated rats versus controls, the increase being proportionally dependent on the length of skin incision. In liver homogenates, CINC1/IL-8 was significantly (P < .01) increased in operated animals versus controls, similarly to serum levels. In contrast, liver TNF-α levels were inversely related to serum levels, and a significant (P < .01) decrease in TNF-α was observed in liver homogenates of operated animals compared with the controls, indicating that the increased TNF-α in blood reflects liver TNF-α secretion.

Conclusion:

Our findings suggest that inflammatory and immune reactions induced by skin-only surgical trauma are closely correlated to the length of skin incision.

Advantages of laparoscopic compared to conventional surgery are not related to an innate immune response of peritoneal immune activation: an animal study in rats

PURPOSE

Laparoscopic surgery (LS) has proved superior compared to conventional surgery (CS) regarding morbidity, length of hospital stay, rate of wound infection and time until recovery. An improved preservation of the postoperative immune function is assumed to contribute to these benefits though the role of the local peritoneal immune response is still poorly understood. Our study investigates the peritoneal immune response subsequent to abdominal surgery and compares it between laparoscopic and conventional surgery to find an immunological explanation for the clinically proven benefits of LS.

METHODS

Wistar rats (N = 140) underwent laparoscopic cecum resection (LCR; N = 28), conventional cecum resection (CCR; N = 28), laparoscopic sham operation (LSO; N = 28), conventional sham operation (CSO; N = 28), or no surgical treatment (CTRL; N = 28). Postoperatively, peritoneal lavages were performed, leukocytes isolated and analyzed regarding immune function and phagocytosis activity.

RESULTS

Immune function was inhibited postoperatively in animals undergoing LCR or CCR compared to CTRL reflected by a lower TNF-α (CTRL 3956.65 pg/ml, LCR 2018.48 pg/ml (p = 0.023), CCR 2793.78 pg/ml (n.s.)) and IL-6 secretion (CTRL 625.84 pg/ml, LCR 142.84 pg/ml (p = 0.009), CCR 169.53 pg/ml (p = 0.01)). Phagocytosis was not affected in rats undergoing any kind of surgery compared to CTRL. Neither cytokine secretion nor phagocytosis activity differed significantly between laparoscopic and conventional surgery.

CONCLUSIONS

According to our findings the benefits associated with LS compared to CS cannot be explained by differences in the postoperative peritoneal innate immune response. Further studies are needed to elucidate the causes for a more favorable postoperative outcome in patients after LS compared to CS.

The tryptophan kynurenine pathway, neopterin and IL-6 during vulvectomy and abdominal hysterectomy

Background

Surgery has wide ranging immunomodulatory properties of which the mechanism is poorly understood. In order to investigate how different types of surgery influence inflammation, we designed a longitudinal observational study investigating two inflammatory profiles of two separate patient groups undergoing gynaecological operations of differing severity. In addition to measuring the well known inflammatory markers neopterin and IL-6, we also determined the kynurenine/tryptophan ratio.

This study was a prospective, single center, two-armed observational study involving 28 female patients. Plasma levels of tryptophan, kynurenine, neopterin and IL-6 were determined from samples taken at: 24hrs pre-operative, prior to induction, ten minutes before the operation was expected to end, and at 24 and 96 hours post operative in patients undergoing abdominal hysterectomy and vulvectomy.

Results

There were 15 and 13 patients included in the vulvectomy and abdominal hysterectomy groups, respectively. In this study we show that anesthesia and surgery significantly increases the enzyme activity of indoleamine 2, 3 dioxygenase (IDO) as measured by the kynurenine/tryptophan ratio (P=0.003), while maintaining stable neopterin levels. However, abdominal hysterectomy causes a considerable IL-6 increase (P<0.001).

Conclusion

Surgery and associated anesthesia cause a significant tryptophan level decrease while significantly increasing IDO activity. Both types of surgery produce nearly identical neopterin time curve relationships, with no significant change occurring in either group. However, even though neopterin is unaffected by the severity of surgery, IL-6 responded to surgical invasiveness by revealing a significant increase during abdominal hysterectomy.

Inflammatory response after open and laparoscopic Nissen fundoplication in children: a randomized study

PURPOSE

It is assumed that laparoscopic surgery generally induces less inflammatory responses than open surgery. Since few studies have compared immune responses after laparoscopic and open surgery in children, we examined inflammatory markers in children randomized to open (ONF) or laparoscopic Nissen fundoplication (LNF).

METHODS

Blood samples were collected prior to surgery (D0), and on postoperative day 1 (D1) and day 2 (D2). Inflammatory markers were measured using a multiplex antibody bead kit. The postoperative levels of inflammatory markers were statistically analyzed using a linear mixed model. A P value <0.05 was considered statistically significant.

RESULTS

Twenty-nine patients randomized to ONF or LNF were included. Median age was 3.1 years (range 1.0-14.2) in the ONF group and 4.0 years (range 0.2-14.2) in the LNF group. Plasma levels of the anti-inflammatory cytokine interleukin (IL)-10 were significantly higher in the ONF group than in the LNF group postoperatively (P = 0.04). However, there were no significant differences between the groups in the levels of pro-inflammatory markers tumor necrosis factor-α, IL-6, IL-8, monocyte chemoattractant protein-1, white blood cell count, or C-reactive protein.

CONCLUSIONS

We did not find that laparoscopy induced a substantially less inflammatory response than laparotomy in children undergoing fundoplication.

Enthusiasm, evidence and ethics: the triple E of minimally invasive pediatric surgery

Minimally invasive techniques are applicable in more than 60% of abdominal and thoracic operations in children. Enthusiasts promoted these techniques for many years. However, level 1 evidence on advantages of minimally invasive surgery in children remains limited. Randomized controlled trials have been conducted for some types of procedures such as laparoscopic appendectomy, fundoplication, pyloromyotomy, and inguinal hernia repair. The results of these studies confirm some advantages of minimally invasive surgery, but for most types of laparoscopic and all types of thoracoscopic procedures, such data remain to be established. This article also focuses on reports on complications and disadvantages which are relevant for final conclusions and recommendations. The ethical implications of the application of new techniques in children are also discussed. On the basis of evidence based data and ethical principles, minimally invasive techniques may be appropriately used in the future.

Transgastric endoscopic pneumoperitoneum versus laparoscopy: effects on host systemic and peritoneal inflammatory responses in a porcine model

BACKGROUND

The host systemic and peritoneal immune responses during natural orifice transluminal endoscopic surgery (NOTES) continues to be delineated. The immune response to laparoscopy (LAP) has been favorably depicted. However, the immunologic effects of NOTES are yet to be determined, and the introduction of contaminants via the host orificium may have deleterious effects. The purpose of this study was to characterize the effect that NOTES would have on porcine systemic and peritoneal immune function.

METHODS

Twenty-four pigs were divided into three groups: ENDO (upper-endoscopy control), NOTES, and LAP. All animals had blood and peritoneal lavage samples collected for cytokine analysis pre- and postoperatively. Interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNFα), and interferon γ (IFNγ) levels were quantified using enzyme-linked immunosorbent assay (ELISA). Peritoneal lavage samples were cultured and identified by group and time of collection for microbiological analysis.

RESULTS

TNFα was found in detectable levels in serum samples of all three groups. For the NOTES group, there was a significant increase in TNFα at t = 1 h (P < 0.01), which dropped significantly at t = 48 h (P < 0.01). IL-1β was present as an early response in NOTES lavage samples (t = 0 and t = 1 h). Both LAP and NOTES had similar elevation of IL-1β in the final lavage samples at t = 48 h. The other cytokines were not consistently found above detectable levels in any group. Similar microbiological contaminants were found in the ENDO and LAP groups. In the NOTES group, no significant growth was observed from cultures at 48 h.

CONCLUSIONS

For measurable cytokines, the NOTES inflammatory response was not significantly different from that of the LAP group. NOTES did not carry a significantly increased amount of microbiological contamination at 48 h compared to LAP. These data suggest that the host immune response to NOTES does not significantly differ from that to LAP in a porcine model.

NOTES new frontier: Natural orifice approach to retroperitoneal disease

AIM: To develop a pure transvaginal access to the retroperitoneum, that is simple, reproducible and uses endoscopic material available on the market.

METHODS: From February 2008 to April 2009, 31 pigs were operated on, with 17 as an acute experiment and 14 with a survival protocol. The animals were placed in a supine position and a 12-mm double-channel endoscope (Karl Storz™, Tuttlingen) was used for vision and dissection. During the same time period, the access experiment was reproduced on 3 human cadavers using material similar to that used in the animal model.

RESULTS: In the animal model, 37 interventions were done on the kidney, adrenal gland and pancreas. The mean time to fashion the access was 10 min (range 5 to 20 min). No intraoperative death was observed. Two major (5%) intraoperative complications occurred: one hemorrhage on the aorta and one tearing of the right renal vein. Peritoneal laceration was encountered in 5 cases without impairing the planned task. In the survival group, good clinical outcome was observed at a mean follow-up of 3 wk (range 2 to 6 wk). In the 3 cadavers, access was performed correctly. The mean time to fashion the access was 52 min (range 40 to 60 min). All the anatomical landmarks described in the pig model were clearly identified in the same sequence.

CONCLUSION: A retroperitoneal natural orifice translumenal surgical transvaginal approach is feasible in both animal and human models and allows performance of a large panel of interventions.

Carbon dioxide modifies the morphology and function of mesothelial cells and facilitates transepithelial neuroblastoma cell migration

BACKGROUND

The response of mesothelial cells to surgical trauma and bacterial contamination is poorly defined. We have recently shown that CO(2) pneumoperitoneum increases systemic metastasis of neuroblastoma cells in a murine model. Thus, we hypothesized that CO(2) alters the morphology and function of mesothelial cells and facilitates transmesothelial tumor cell migration.

MATERIALS AND METHODS

Murine mesothelial cells were exposed to 100% CO(2) and 5% CO(2) as control. Scanning electron microscopy (SEM) investigations, as well as LPS-induced granulocyte-colony stimulating factor (G-CSF) production and mitochondrial activity (MTT assay) were measured. Transmesothelial migration of neuroblastoma cells (Neuro2a) was determined using a transwell chamber system.

RESULTS

CO(2) incubation was associated with a significant destruction of the microvillar formation in SEM. Migration studies showed that the barrier function of the mesothelial monolayer decreased. A significantly increased migration of neuroblastoma cells was identified after 100% CO(2) exposure (P < 0.05). Although the conversion of MTT as an indicator of mitochondrial activity was only slightly and not significantly reduced after CO(2) incubation, the release of G-CSF induced by LPS was completely blocked during the incubation with 100% CO(2) (P < 0.05). The capacity of G-CSF release recovered after the incubation.

CONCLUSION

We observed that peritoneal mesothelial cells lose their typical cell morphology by CO(2) incubation, which is accompanied by facilitated migration of neuroblastoma cells. Moreover, the synthesis of immunological factors is blocked, but this effect is not long lasting. These mechanisms may explain an increased metastasis rate of neuroblastoma cells after CO(2) pneumoperitoneum, which was recently observed in a murine model.

Endometriosis-induced vaginal hyperalgesia in the rat: role of the ectopic growths and their innervation

Endometriosis is a painful disorder defined by extrauteral endometrial growths whose contribution to pain symptoms is poorly understood. Endometriosis is created in rats by autotransplanting on abdominal arteries pieces of either uterus (ENDO), which form cysts, or fat (shamENDO), which do not form cysts. ENDO, but not shamENDO induces vaginal hyperalgesia. We tested the hypothesis that the cysts are necessary to maintain vaginal hyperalgesia by assessing the effect of surgically removing them. Complete-cyst-removal eliminated ENDO-induced vaginal hyperalgesia up to 4 months post-operatively. Sham-cyst-removal in ENDO rats, in which cysts were not removed, or partial cyst-removal increased the ENDO-induced hyperalgesia. The decreases and increases both took 3-6 weeks to develop. Changes in ENDO-induced hyperalgesia did not occur in a control group of ENDO rats who had no surgery after ENDO. In a double-surgery control group, neither shamENDO surgery nor a subsequent sham surgery that mimicked "removal" of non-existent cysts influenced vaginal nociception. In a no-surgery control group, vaginal nociception remained stable for >6 months. The increases in ENDO-induced hyperalgesia produced by the sham-cyst-removal surgery were smaller in proestrus than in other estrous stages. During the other stages (but not during proestrus), sympathetic innervation of the cysts increased. These results suggest that maintenance of ENDO-induced vaginal hyperalgesia requires continued presence of at least some ectopic endometrial tissue, and that surgical treatment that fails to remove ectopic endometrial tissue can exacerbate the hyperalgesia, possibly due in part to an increase in the cysts' sympathetic innervation.

Early effects of laparotomy and laparoscopy on bacterial behavior and proinflammatory cytokines on bacterial peritonitis in rats I: Escherichia coli

PURPOSE

The aim of this study was to investigate in rats with peritonitis the effect of CO2 insufflation on behavior of bacteria, including antibiotic resistance, and the systemic and regional host response.

METHODS

Inbred weaned Wistar albino rats were used. Escherichia coli ATCC 25922 was used to induce peritonitis. Rats with peritonitis were allocated to 4 groups: group 1, control; group 2, laparotomy; group 3, laparoscopy; group 4, laparoscopy + laparotomy and were killed at the end of the second hour of peritonitis. Serum, peritoneal fluid, and intraabdominal organs were taken for microbiological (biochemical markers-urease, citrate, indole; virulence factors-biofilm, protease, gelatinase, adherence), systemic immunologic (interleukin 1 [IL-1]alpha, IL-1beta, tumor necrosis factor alpha, IL-6), and regional histopathologic evaluations. Isolated strains were tested against minimum inhibitory concentrations (MICs) and sub-MICs of amikacin and amoxicillin.

RESULTS

Regional inflammatory response was the highest in group 2 but the lowest in group 4. Systemic IL-1alpha level was significantly higher in group 2, and TNF-alpha level was higher in group 3. After the peritonitis process, Escherichia coli began to use citrate and urea in control groups (without antibiotic treatment). In groups 2 and 4, amoxicillin resistance developed.

CONCLUSIONS

In peritonitis, in all experimental groups, Escherichia coli used different metabolic pathways other than in normal atmospheric conditions. Amoxicillin resistance developed in open surgery groups. Further kinetic microbiological and immune response studies are needed concerning the early and late effects of CO2 insufflation on various strains of bacteria and mixed infections.

Impact of surgery on immunologic function: comparison between minimally invasive techniques and conventional laparotomy for surgical resection of colorectal tumors

BACKGROUND

Surgical trauma suppresses host immune function, potentially creating an environment vulnerable to tumor cell growth. This study compared immune function after laparoscopy, minilaparotomy, and conventional colorectal tumor resections.

METHODS

Seventy-one patients underwent surgery (20 laparoscopy, 21 minilaparotomy, and 30 conventional). Blood samples were taken before surgery and at 3 hours, 24 hours, and 5 days after surgery. White blood cell constitution was determined using monoclonal antibodies. Levels of TH1 cytokines interferon-gamma, tumor necrosis factor-alpha, and interleukin (IL)-2 and TH2 cytokines IL-10, -4, and -6 were measured in plasma and from supernatants of activated peripheral blood mononuclear cells.

RESULTS

At 5 days after surgery, lymphocyte counts remained low in the conventional and minilaparotomy groups (P = .001 and P = .008) but had resolved in laparoscopic patients. Three-hour postoperative serum IL-6 concentrations were lower in laparoscopic than in conventional patients (P = .028). Production of TH1 cytokines 3 hours after surgery were significantly increased in laparoscopic patients (interferon-gamma P = .018, tumor necrosis factor-alpha P = .011, and IL-2 P = .037).

CONCLUSIONS

TH1 lymphocyte function is improved transiently and immune homeostasis restored earlier in patients undergoing laparoscopic colorectal cancer resection, which may influence disease recurrence.

Late phase TNF-alpha depression in natural orifice translumenal endoscopic surgery (NOTES) peritoneoscopy

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) allows access to the peritoneal cavity without skin incisions. Contamination of the peritoneal cavity by enteric contents may render NOTES more physiologically and immunologically invasive than previously thought. Measurement of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) is a validated method to quantify surgical stress. The physiologic and immunologic impact of NOTES is unknown.

METHODS

A total of 37 swine underwent abdominal exploration via transgastric NOTES peritoneoscopy, laparoscopy (LX), laparotomy (OPEN), or sham surgery (CONTROL) and were allowed to survive. TNF-alpha, IL-1beta, and IL-6 plasma levels were determined at the start and completion of surgery, and at 1 hour, 2 days, and 14 days postoperatively.

RESULTS

At surgical completion, OPEN animals demonstrated higher TNF-alpha levels than all groups. TNF-alpha levels were similar for all groups at 1 hour and 2 days. NOTES animals had significantly reduced plasma levels of TNF-alpha than all other groups on postoperative days 7 and 14. Controlling for baseline cytokine variability, analysis was repeated using normalized data, which confirmed significantly reduced TNF-alpha levels for NOTES compared with all groups at 14 days. Subset analysis excluding LX and OPEN complications revealed lower NOTES TNF-alpha levels at 7 and 14 days compared with all groups. IL-1beta and IL-6 levels were undetectable in 66.8% and 70.5% of samples, respectively, without significant trends.

CONCLUSIONS

Diagnostic NOTES peritoneoscopy demonstrated similar levels of systemic proinflammatory cytokine TNF-alpha compared with diagnostic laparoscopy and exploratory laparotomy in the immediate postoperative period despite gross intraperitoneal contamination. None of the surgical groups, however, produced a measurable, consistent trend in IL-1beta or IL-6. Consistently reduced levels of TNF-alpha in NOTES animals in the late postoperative period indicates an immunomodulatory effect of the NOTES surgical technique not present in laparoscopy or laparotomy.

Carbon dioxide directly suppresses spontaneous migration, chemotaxis, and free radical production of human neutrophils

BACKGROUND

Carbon dioxide (CO(2)) insufflation during laparoscopy has been shown to dampen the systemic stress response to surgery. This is related to a suppression of peritoneal macrophage functions. In vivo data suggest that CO(2) can also affect neutrophils (polymorphonuclear cells, PMNs), the most abundant cell type in the inflamed peritoneal cavity. Nonetheless, the direct effects of CO(2) on PMNs have not yet been investigated.

METHOD

PMNs were isolated from peripheral blood of healthy volunteers and incubated with (1) CO(2) (100% CO(2), pH 6.2), (2) hypoxic control (95% helium/5% CO(2), pH 7.4), and (3) control (95% air/5% CO(2), pH 7.4). Spontaneous and IL-8-induced migrations (chemokinesis and chemotaxis) during 2 h of exposure to different gases were measured with a transwell chamber system. The release of reactive oxygen species (ROS, luminometry) was determined after 15-min and 2-h exposures. In other sets of experiments, PMNs were exposed for 2 h or 4 h and kept under normal conditions for 18 h with lipopolysaccharide (LPS) stimulation thereafter. Final viability and apoptosis were assessed with fluorometry.

RESULTS

Exposure to 100% CO(2) completely blocked spontaneous and IL-8 induced migration of PMNs (p < 0.001 vs. controls). Neutrophil migration was slightly diminished in the hypoxic control group. PMA-stimulated ROS production was reduced even after short exposure to 100% CO(2)(p < 0.05). We observed a slight increase of caspase-3/7 activity after exposure to 100% CO(2) and/or hypoxia; however, total viability was not affected.

CONCLUSIONS

CO(2) incubation directly and temporarily suppresses the proinflammatory functions of PMNs; this is caused only partially by the concomitant hypoxia. This effect will contribute to the dampened inflammatory response to laparoscopic surgery. Further studies are needed to investigate whether the temporary suppression of neutrophil functions could affect the clearance of bacterial contaminations.

Physiological responses to endoscopic surgery in children

The knowledge on the physiological impact of endoscopic surgery in infants and children is limited. Cardiovascular effects of pneumoperitoneum are mainly the result of an increase in intraabdominal pressure, absorption of carbon dioxide, and a stimulation of the neurohumoral vasoactive system. In infants, pneumoperitoneum alters the heart rate, mean arterial pressure, left ventricular endsystolic and end-diastolic volume, and meridional wall stress. Urine production is significantly reduced, and cerebral oxygenation and blood flow are altered. However, postoperative immune function is preserved or restored faster, and specific physiological responses to endoscopic surgery are well tolerated by otherwise healthy infants and children. The effects in children with specific conditions, such as sepsis, cancer, or organ dysfunction, remain to be investigated.