Mini-laparotomy and full laparotomy, but not laparoscopy, alter hepatic macrophage populations in a rat model

Effects of CO2 pneumoperitoneum on proliferation, apoptosis, and migration of gastrointestinal stromal tumor cells

BACKGROUND

The purpose of the study was to investigate the proliferation and migration capability of human gastrointestinal stromal tumor line GIST-T1 after exposure to different pressures and times of CO₂ pneumoperitoneum.

METHODS

We established simulated CO₂ pneumoperitoneum environment in vitro and divided the human GIST cell GIST-T1 into open control group, 8 mmHg CO₂ pneumoperitoneum treatment group and 15 mmHg CO₂ pneumoperitoneum treatment group. Each group was divided into two subgroups respectively cultured for 1 h and 3 h. pH value of cell culture, cell growth curve, and cell cycle distribution of each group was measured. By application of scratch healing tests and Transwell chamber experiments, mobility ratio and number of cells through 8 µm membranes were measured to assess the migration ability of cells in each group after intervention.

RESULTS

Cell culture pH value of each subgroup in CO₂ group decreased significantly after exposed in CO₂ pneumoperitoneum (P < 0.01). The proliferation of GIST-T1 cells in 15 mmHg CO₂ group was significantly inhibited early (1-2 days) (P < 0.05) and the proliferation of GIST-T1 cells in 8 mmHg CO₂ 1 h subgroup and 15 mmHg CO₂ 1 h subgroup was increased significantly late (4-6 days) (P < 0.05) after the interventions of CO₂ pneumoperitoneum. The percentage of cells in G0-G1 phase increased, the percentage of S phase cells decreased (P < 0.01) in 1-h subgroup and 3-h subgroup of 15 mmHg CO₂ group 24 h after exposure to CO₂. The percentage of cells in S phase increased in 1-h subgroup of 8 mmHg CO₂ group and decreased in 3-h subgroup of 15 mmHg CO₂ group 72 h after exposure to CO₂. In the Transwell chamber experiment, the cell number through 8-µm membrane increased significantly (P < 0.01) in 3-h subgroup of CO₂ group compared to that in 3-h subgroup of control group.

CONCLUSIONS

The routine pressure and duration of CO₂ pneumoperitoneum used in clinic did not promote the proliferation of gastrointestinal stromal tumors, but had a potential risk of increasing postoperative recurrence and distant metastasis.

Does pneumoperitoneum adversely affect growth, development and liver function in biliary atresia patients after laparoscopic portoenterostomy?

PURPOSE

We assessed the effect of high partial pressure of arterial carbon dioxide (PaCO2) due to pneumoperitoneum (PP) on growth (height/weight) and development (gross/fine motor function, receptive/expressive communication, and social interaction), by comparing outcome after portoenterostomy (PE) for biliary atresia (BA) using laparoscopic PE (LPE: n = 13) and open PE (OPE: n = 13) cases performed between 2005 and 2014.

METHODS

Our PE is based on Kasai's original PE. All data were collated prospectively.

RESULTS

Differences in duration of follow-up (LPE: 38.8 months; OPE: 38.1 months), jaundice clearance (LPE: 12/13 = 92.3 %; OPE: 9/13 = 69.2 %), survival with the native liver (LPE: 10/13 = 76.9 %; OPE: 9/13 = 69.2 %), incidence of cholangitis, hypersplenism, and incidence of esophageal varices were not significant. Mean intraoperative PaCO2 was significantly higher in LPE (LPE: 50.1 mmHg; OPE: 40.7 mmHg, p < 0.05). Liver function impairment was not statistically different, although LPE results were slightly worse. There was no overall delay in growth observed, although height/weight gain was more consistent in LPE. The pattern of developmental delay observed was similar for LPE and OPE suggesting that developmental delay is not PE-related; in other words, PP is not implicated in developmental delay.

CONCLUSIONS

PP during LPE would appear to have no adverse effects on overall growth/development and liver function in BA patients.

Laparoscopic Kasai portoenterostomy for biliary atresia

Minimally invasive surgery requires mastery of complex skills and exhaustive knowledge of anatomic variations but the patient benefits from excellent cosmesis, less requirement for analgesia and respiratory support, and a reduced incidence of postoperative morbidity, such as bowel adhesions and incisional hernias. Laparoscopic portoenterostomy is being performed with encouraging results after the open extended portoenterostomy procedure currently performed was revised to more closely resemble the original procedure developed by Kasai in the 1950s. Thus, the risk for damage to micro bile ducts around the porta hepatis is minimized because deep suturing and extensive dissection are eliminated.

Laparoscopic surgery for biliary atresia and choledochal cyst

Minimally invasive surgery in children has evolved to the extent that complex procedures can be performed with safety and outcome comparable with open surgery, with the advantage of minimal scarring. Here we describe the latest laparoscopic techniques used by us at the Juntendo University Hospital, Japan, for treating biliary atresia and choledochal malformation, with presentation of our postoperative management and discussion of preliminary outcomes.

Initial experience of single-incision laparoscopic hepaticojejunostomy using conventional instruments for correctable biliary atresia

BACKGROUND/PURPOSE

Single-incision laparoscopic surgery aims to minimize surgical trauma. Yet there has been no report on its application to the treatment of correctable biliary atresia (BA). We present here our initial mini-series of successful single-incision laparoscopic hepaticojejunostomy (SILH) for correctable BA.

PATIENTS AND METHODS

We reviewed 4 correctable BA patients (Type I/II, 3/1) who underwent SILH between May and July 2011. Ultrasonography, upper gastrointestinal contrast studies, and blood tests were performed during the follow-up period. The age at operation, operative time, postoperative hospital stay, resumption of full diet, postoperative complications, and perioperative laboratory tests were evaluated.

RESULTS

The median age at operation was 21 days. The median operative time was 2 hours. Blood loss was minimal. The median follow-up duration was 4.5 months. Jaundice gradually declined after 3-5 days in Type I and 6 days in Type II BA patient. There was no mortality or surgical complication so far.

CONCLUSIONS

In experienced hands, SILH for treatment of correctable BA is safe and effective.

An unbiased stereological study on subpopulations of rat liver macrophages and on their numerical relation with the hepatocytes and stellate cells

Studies on liver macrophages have elucidated their key roles in immunological, fibrotic and regenerative responses, and shown that macrophages are not a homogeneous population. In the rat, two sets of liver macrophages coexist, identified by ED1 and ED2 antibodies. Those sets have different quantitative responses in liver injuries and may have different tasks throughout the injury and recovery phases. Nevertheless, the total number (N), number per gram (N g(-1)) and proportion of those macrophages in relation to other liver cells has never been quantified using design-based stereology. Thus, we combined immunocytochemistry with those tools to produce an unbiased estimate of the N of ED1(+) and of ED2(+) cells. A smooth fractionator sampling scheme was applied to the liver of five male Wistar rats (3 months old), to obtain systematic uniform random sections (30 microm thick); these were immunostained with the monoclonal antibodies: ED1, a pan-macrophagic marker; and ED2, which identifies the completely differentiated macrophages, i.e. Kupffer cells. The N of ED1(+) cells was 340 x 10(6), estimated with a coefficient of error (CE) of 0.04, and that of ED2(+) cells was 283 x 10(6), with a CE of 0.05. These figures correspond to 10.7% and 8.9%, respectively, of the total liver cells. The new data constitute reference values for correlative inferences. Also, the methodological strategy, by its accuracy and precision, is valuable for future investigations on the liver cell composition in various models of disease, and especially for studying the more subtle variations that occur during the injury and recovery phases.

Renal ischemia-reperfusion leads to long term infiltration of activated and effector-memory T lymphocytes

It is well-established that significant ischemia-reperfusion injury during kidney transplantation results in increased incidence of long-term fibrosis and rejection. To test for a role of T cell infiltration and activation following ischemic injury, we induced both bilateral and unilateral renal ischemia in mice, followed by reperfusion, and then isolated mononuclear cells. Analysis of these cells by flow cytometry showed that 2 weeks after bilateral ischemia there was a significant increase of CD8(+) T cells. Furthermore, both CD4(+) and CD8(+) T cells infiltrated the injured kidney 6 weeks after unilateral ischemia. These T cells had increased expression of CD69(+) and CD44(hi)CD62L(-), markers of activation and effector-memory, respectively. CD4(+)NK1.1(+) and CD19(+) B cells were decreased in percentage both 6 and 11 weeks after bilateral or unilateral injury. There was a significant upregulation of IL-1beta, IL-6, TNF-alpha, IFN-gamma, MIP-2, and RANTES expression, measured by real-time PCR, 6 weeks after unilateral renal ischemia, further indicating T cell activation. Depletion of CD4(+) and CD8(+) T cells before ischemia caused less medullary damage and reduced kidney IFN-gamma expression, whereas their depletion following ischemia increased kidney IL-1beta; however, depletion of these cells had no effect on histological damage to the kidney. Our study demonstrates that moderate or severe kidney ischemia induces long-term T lymphocyte infiltration and cytokine/chemokine upregulation, leading to kidney structural changes.

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.

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

PURPOSE

Laparoscopy has been associated with lower inflammatory responses. However, it has been postulated that minilaparotomy, in contrast to full laparotomy, is equally minimally invasive.

OBJECTIVE

The aim of this study was to investigate local, systemic, and distant organ immune responses after different surgical approaches to the abdominal cavity, such as minilaparotomy, full laparotomy, and laparoscopy, in a small animal model.

METHODS

Male Lewis rats received a permanent central venous catheter and were randomized to 4 groups (n = 6 per group). The animals were subjected to anesthesia alone (control), minilaparotomy (1 cm), full laparotomy (7 cm), or laparoscopy for 60 minutes. Blood was collected via the central venous catheter before as well as 1 hour and 6 hours after the start of intervention. Peritoneal and bronchoalveolar lavages, as well as heart puncture, were performed after 24 hours.

RESULTS

All surgical interventions led to a significant migration of polymorphonucleocytes into the abdominal cavity. Full laparotomy resulted in a significant increase in nitric oxide production by peritoneal macrophages as compared with control. Macrophage nitric oxide production after laparoscopy and minilaparotomy was not significantly different. A shift in the expression of OX-6 and CD54 was only detected after full laparotomy. Systemically, O(2)(-) release by circulating mononuclear cells was significantly increased after minilaparotomy and full laparotomy, but not after laparoscopy. The systemic levels of IL6 were significantly accelerated only after full laparotomy, with a maximum after 6 hours. In the lungs, function of alveolar macrophages was not altered in any group.

CONCLUSIONS

Any approach to the peritoneal cavity causes local inflammatory responses. Full laparotomy alters peritoneal macrophage functions more pronouncedly than does minilaparotomy or laparoscopy. Systemic inflammatory responses, such as free oxygen radical release, are significantly increased by both minilaparotomy and full laparotomy, whereas laparoscopy preserves systemic immune function. Our results may lead to further preference for the laparoscopic approach over minilaparotomy and full laparotomy.

Exposure to carbon dioxide and helium reduces in vitro proliferation of pediatric tumor cells

BACKGROUND

Minimally invasive techniques are increasingly applied to children with malignant tumors. We showed previously that CO(2) used for pneumoperitoneum modulates the function of macrophages and polymorphonuclear cells via direct effects and via acidification. Numerous in vitro and small animal model studies also confirmed an alteration of the behavior of several types of adult tumor cells by CO(2). The impact of CO(2) and other gases used for pneumoperitoneum on the behavior of various pediatric tumors has not yet been determined.

METHODS

Cell lines of neuroblastoma (IMR 32, SK-N-SH, Sy5y), lymphoma (Daudi), hepatoblastoma (Huh 6), hepatocellular carcinoma (Hep G2), and rhabdomyosarcoma (Te 671) were incubated for 2 h. Incubation was performed with 100% CO(2), 100% helium, and 5% CO(2) as control. Cell proliferation was determined by the MTT-assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] by actively growing cells to produce a blue formazan product. The MTT-assay was performed before, directly after incubation, and daily for 4 days. Vitality of the cells was determined by trypan blue. The extracellular pH during incubation was measured during gas exposition every 10 min using Bayer Rapid Lab 855.

RESULTS

CO(2) for 2 h significantly decreased the proliferation of neuroblastoma, lymphoma, hepatoblastoma, and hepatocellular carcinoma cells. This decrease persisted over 4 days in neuroblastoma, lymphoma, and hepatocellular carcinoma cells. The CO(2) had no impact on hepatoblastoma and rhabdomyosarcoma cells. Helium had a similar effect on neuroblastoma cells. After 4 days, a significant decrease of cell activity was found in two neuroblastoma cell lines and in hepatoblastoma cells. Helium had no effect on lymphoma and hepatocellular carcinoma cells. The extracellular pH was 6.2 during incubation with CO(2), and 7.6 during incubation with helium.

CONCLUSION

CO(2) and helium may affect the proliferation of some pediatric tumor cell lines in vitro. However, some of these effects and the impact on the extracellular pH are differential. The role of pH modulation, hypoxia and direct effects of gases remain to be investigated before a general recommendation on the use of minimally invasive techniques in pediatric oncology can be given.