Influence of CO_2 pneumoperitoneum on intracellular pH and signal transduction in cancer cells

Object: The authors studied the influence of CO2 pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation. Method: They set up a simulation of pneumoperitoneum under different CO2 pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated. Result: When the pressure of CO2 pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5,178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15×105, 2.03×105, 2.20×105, 2.18×105 L-1. Conclusion: CO2 pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.

Two clinically relevant pressures of carbon dioxide pneumoperitoneum cause hepatic injury in a rabbit model

AIM:To observe the hepatic injury induced by carbon dioxide pneumoperitoneum(CDP) in rabbits,compare the eects olow-and high-pressure pneumoperitoneum,and to determine the degree o hepatic injury induced by these two clinically relevant CDP pressures.METHODS:Thirty healthy male New Zealand rabbits weighing 3.0 to 3.5 kg were randomly divided into three groups(n = 10 for each group) and subjected to the ollowing to CDP pressures:no gas control,10 mmHg,or 15 mmHg.Histological changes in liver tissues were observed with hematoxylin and eosin staining and transmission electron microscopy.Liver unction was evaluated using an automatic biochemical analyzer.Adenine nucleotide translocator(ANT) activity in liver tissue was detected with the atractyloside-inhibitor stop technique.Bax and Bcl-2 expression levels were detected bywestern blotting.RESULTS:Liver Functions in the 10 mmHg and 15 mmHg experimental groups were significantly disturbed compared with the control group.After CDP,the levels or alanine transaminase and aspartate transaminase were 77.3 ± 14.5 IU/L and 60.1 ± 11.4 IU/L,respectively,in the 10 mmHg experimental group and 165.1 ± 19.4 IU/L and 103.8 ± 12.3 IU/L,respectively,in the 15 mmHg experimental group,which were all higher than those of the control group(p < 0.05).There was no difference in pre-albumin concentration between the 10 mmHg experimental group and the control group,but the prealbumin level of the 15 mmHg experimental group was significantly lower than that of the control group(p < 0.05).No significant differences were observed in the levels of total bilirubin or albumin among the three groups.After 30 and 60 min of CDP,pH was reduced(p < 0.05) and fa CO2 was elevated(p < 0.05) in the 10 mmHg group compared with controls,and these changes were more pronounced in the 15 mmHg group.Hematoxylin and eosin staining showed no significant change in liver morphology,except for mild hyperemia in the two experimental groups.Transmission electron microscopy showed mild mitochondrial swelling in hepatocytes of the 10 mmHg group,and this was more pronounced in the 15 mmHg group.No significant difference in ANT levels was found between the control and 10 mmHg groups.However,ANT concentration was significantly lower in the 15 mmHg group compared with the control group.The expression of hepatic Bax was significantly increased in the two experimental groups compared with the controls,but there were no differences in Bcl-2 levels among the three groups.Twelve hours after CDP induction,the expression of hepatic Bax was more significant in the 15 mmHg group than in the 10 mmHg group.CONCLUSION:A CDP pressure of 15 mmHg caused more substantial hepatic injury,such as increased levels of acidosis,mitochondrial damage,and apoptosis;therefore,10 mmHg CDP is preferable for laparoscopic operations.

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats

AIM： To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism.METHODS： Thirty healthy male SD rats were randomly divided into control group （n = 10）, 0 h experimental group （n = 10） and 1 h experimental group （n = 10） after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver tissue were observed with hematoxylineosin staining. Liver function was assayed with an automatic biochemical analyzer. Concentration of malonyldialdehyde （MDA） and activity of superoxide dismutase （SOD） were assayed by colorimetry. Activity of adenine nucleotide translocator in liver tissue was detected with the atractyloside-inhibitor stop technique. Expression of hypoxia inducible factor-1 （HIF-1） mRNA in liver tissue was detected with in situ hybridization.RESULTS： Carbon dioxide 60 min could induce liver pneumoperitoneum for injury in rats. Alanine aminotransferase and aspartate aminotransferase were 95.7 ± 7.8 U/L and 86.8 ± 6.9 U/L in 0 h experimental group, and 101.4 ± 9.3 U/L and 106.6 ±8.7 U/L in 1 h experimental group. However, no significant difference was found in total billirubin, albumin, and pre-albumin in the three groups. In 0 h experimental group, the concentration of MDA was 9.83 ±2.53 μmol/g in liver homogenate and 7.64 ± 2.19 μmol/g in serum respectively, the activity of SOD was 67.58±9.75 nu/mg in liver and 64.47 ± 10.23 nu/mg in serum respectively. In 1 h experimental group, the concentration of MDA was 16.57±3.45 μmol/g in liver tissue and 12.49 ±4.21 μmol/g in serum respectively, the activity of SOD was 54.29 ±7.96 nu/mg in liver tissue and 56.31 ±9.85 nu/mg in serum respectively. The activity of ANT in liver tissue was 9.52 ± 1.56 in control group, 6.37± 1.33 in 0 h experimental group and 7.2 8±1.45 （10^-9 mol/min per gram protein） in 1 h experimental group, respectively. The expression of HIF-1 mRNA in liver tissue was not detected in control group, and its optical density difference value was 6.14±1.03 in 0 h experimental group and 9.51 ± 1.74 in 1 h experimental group, respectively. CONCLUSION： Carbon dioxide pneumoperitoneum during the sham operation can induce hepatic injury in rats. The probable mechanisms of liver injury include anoxia, ischemia reperfusion and oxidative stress. Liver injury should be avoided during clinical laparoscopic operation with carbon dioxide pneumoperitoneum.

Low-pressure pneumoperitoneum with abdominal wall lift in laparoscopic total mesorectal excision for rectal cancer:initial experience

AIM To evaluate the safety and feasibility of a new technology combining low-pressure pneumoperitoneum(LPP) and abdominal wall lift(AWL) in laparoscopic total mesorectal excision(TME) for rectal cancer.METHODS From November 2015 to July 2017,26 patients underwent laparoscopic TME for rectal cancer using LPP(6-8 mm Hg) with subcutaneous AWL in Qilu Hospital of Shandong University,Jinan,China.Clinical data regarding patients' demographics,intraoperative monitoring indices,operation-related indices andpathological outcomes were prospectively collected.RESULTS Laparoscopic TME was performed in 26 cases(14 anterior resection and 12 abdominoperineal resection) successfully,without conversion to open or laparoscopic surgery with standard-pressure pneumoperitoneum.Intraoperative monitoring showed stable heart rate,blood pressure and paw airway pressure.The mean operative time was 194.29 ± 41.27 min(range:125-270 min) and 200.41 ± 20.56 min(range:170-230 min) for anterior resection and abdominoperineal resection,respectively.The mean number of lymph nodes harvested was 16.71 ± 5.06(range:7-27).There was no positive circumferential or distal resection margin.No local recurrence was observed during a median follow-up period of 11.96 ± 5.55 mo(range:5-23 mo).CONCLUSION LPP combined with AWL is safe and feasible for laparoscopic TME.The technique can provide satisfactory exposure of the operative field and stable operative monitoring indices.

Idiopathic neonatal pneumoperitoneum with favorable outcome: A case report and review

Neonatal pneumoperitoneum is a surgical emergency indicative of gastrointestinal perforation that requires immediate treatment to prevent death. There have been non-surgical conditions secondary to neonatal pneumoperitoneum(e.g., mechanical ventilation, pulmonary diseases and pneumatosis cystoides intestinalis) that neonates were able to overcome without the need for abdominal exploration. Idiopathic pneumoperitoneum, although similar to perforation of the alimentary tract and the previously mentioned non-surgical conditions, is a more rare and benign condition that does not yet have a definite cause. Hence, inexperienced surgeons may have a difficult time providing the right treatment for idiopathic pneumoperitoneum. We report a case of a neonate with a massive pneumoperitoneum who obtained a favorable outcome without surgical intervention. Nonetheless, the cause of pneumoperitoneum remains unclear. We hypothesize that the right sized perforation(range: 2 mm to 4 mm in diameter) at the anterior wall of the stomach is needed for pneumoperitoneum to occur. As the baby cries(aerophagia), the air in the stomach accumulates until it can enter the intraperitoneal cavity through the leak compressed by gastric peristalsis, hence forming a large pneumoperitoneum. Small amounts of gastric juice are able to penetrate the gastric wall; therefore, no signs or symptoms of peritonitis occur. The gastric leak self-seals, preventing further passage of the air, allowing the intraperitoneal free gas to dissipate gradually. This case demonstrated that laparotomy can be avoided in neonates with idiopathic pneumoperitoneum if a timely diagnosis is established.

Inhibitory effects of carbon dioxide insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy

AIM:To evaluate the inhibitory effects of carbon dioxide (CO2) insufflation on pneumoperitoneum and bowel distension after percutaneous endoscopic gastrostomy (PEG).METHODS:A total of 73 consecutive patients who were undergoing PEG were enrolled in our study.After eliminating 13 patients who fitted our exclusion criteria,60 patients were randomly assigned to either CO2 (30 patients) or air insufflation (30 patients) groups.PEG was performed by pull-through technique after threepoint fixation of the gastric wall to the abdominal wall using a gastropexy device.Arterial blood gas analysis was performed immediately before and after the procedure.Abdominal X-ray was performed at 10 min and at 24 h after PEG to assess the extent of bowel distension.Abdominal computed tomography was performed at 24 h after the procedure to detect the presence of pneumoperitoneum.The outcomes of PEG for 7 d postprocedure were also investigated.RESULTS:Among 30 patients each for the air and the CO2 groups,PEG could not be conducted in 2 patients of the CO2 group,thus they were excluded.Analyses of the remaining 58 patients showed that the patients' backgrounds were not significantly different between the two groups.The elevation values of arterial partial pressure of CO2 in the air group and the CO2 group were 2.67 mmHg and 3.32 mmHg,respectively (P = 0.408).The evaluation of bowel distension on abdominal X ray revealed a significant decrease of small bowel distension in the CO2 group compared to the air group (P < 0.001) at 10 min and 24 h after PEG,whereas there was no significant difference in large bowel distension between the two groups.Pneumoperitoneum was observed only in the air group but not in the CO2 group (P = 0.003).There were no obvious differences in the laboratory data and clinical outcomes after PEG between the two groups.CONCLUSION:There was no adverse event associated with CO2 insufflation.CO2 insufflation is considered to be safer and more comfortable for PEG patients because of the lower incidence of pneumoperitoneum and less distension of the small bowel.

Distinctive clinical features of spontaneous pneumoperitoneum in neonates: A retrospective analysis

BACKGROUND Spontaneous pneumoperitoneum(SP) without gastrointestinal perforation rarely occurs in neonates, with most SP cases being idiopathic. Although SP usually follows a benign clinical course with favorable prognosis, it can become lifethreatening in certain situations. In these cases, urgent surgical intervention may be required. Therefore, it may be difficult to decide when or how to perform prompt interventions.AIM To demonstrate the distinct clinical features of SP to guide appropriate management by comparing characteristics between SP and typical pneumoperitoneum secondary to gastrointestinal perforation.METHODS We retrospectively reviewed electronic medical records and identified 37 neonates with radiological evidence of pneumoperitoneum who were treated at our institution. Clinical variables were compared between neonates with SP without gastrointestinal perforation(Group A) and those with pneumoperitoneum secondary to gastrointestinal perforation(Group B). Clinical variables between groups were compared using Student’s t-test and the chi-square test. The risk factors related to mortality were examined using multi-logistic regression analysis.RESULTS Group A comprised 35.1%(13/37) of the patients. The frequency of persistent pulmonary hypertension(53.8%) and pneumothorax(46.2%) before the development of pneumoperitoneum was significantly higher in group A than in group B(P =0.004). Platelet count and partial pressure of arterial oxygen(PaO) were significantly lower in group A(P = 0.015 and 0.025, respectively). Overall mortality was significantly higher in group A than in group B(76.9% vs 16.7%, P = 0.001). Only preterm infants were significantly associated with high mortality(P = 0.041;odds ratio = 18.0). Accompaniment with persistent pulmonary hypertension and pneumothorax were also significantly high(P = 0.004) in group A, but these were not strongly associated with high mortality.CONCLUSION This study identified a higher mortality rate in patients with SP than that described in previous reports. Neonates with SP were more likely to have thrombocytopenia, pneumothorax, and persistent pulmonary hypertension. Prematurity was the most significant factor affecting mortality.

A rare etiology of post-endoscopic retrograde cholangiopancreatography pneumoperitoneum

Major complications of endoscopic retrograde cholangiopancreatography (ERCP) include pancreatitis, hemorrhage, cholangitis, and duodenal perforation. The occurrence of free air in the peritoneal cavity post- ERCP is a rare event (< 1%), which is usually the result of duodenal or ductal perforation related to therapeutic ERCP with sphincterotomy. We describe for the first time a different aetiology of pneumoperitoneum, in an 84-year-old woman with pancreatic cancer and a large hepatic metastasis, after ERCP with common bile duct stent deployment. Our patient developed, pneumoperitoneum due to air leakage from rupture of intrahepatic bile ducts and Glisson’s capsule in the area of a peripheral large hepatic metastasis. The potential mechanism underlying this complication might be post- ERCP pneumobilia and increased pressure of intrahepatic bile ducts leading to rupture of intrahepatic bile ducts in the liver metastatic mass owing to neoplastic tissue friability. This case indicates the need for close clinical and radiological observation of patients with hepatic masses (primary or metastatic) subjected to ERCP. In such patients, avoidance of excessive air insufflation during ERCP and/or placement of a nasogastric tube for bowel decompression immediately after ERCP might be a reasonable strategy to prevent such unusual complications.

Postoperative pneumoperitoneum after colorectal surgery:Expectant vs surgical management

Postoperative pneumoperitoneum poses a clinical dilemma.Depending on the cause,its management includes a spectrum from simple observation and supportive care to surgical exploration.The aim of this paper is to present four clinical cases and propose an algorithm for the management of postoperative pneumoperitoneum based on available literature.The causes,diagnosis and possible complications arising from pneumoperitoneum will also be discussed.Three of the four cases presented were successfully managed conservatively and one had an exploratory laparotomy with negative findings.In such scenarios,it is important to consider the nonsurgical causes of pneumoperitoneum,which include pseudopneumoperitoneum,thoracic,abdominal,gynecological and idiopathic.These causes do not always require emergent exploratory laparotomy.The surgical team needs to consider the history,physical exam and diagnostic workup of the patient.If a patient presents with peritoneal signs,then exploratory laparotomy is a must.Since 10%of the cases of pneumoperitoneum are caused by nonsurgical entities,managed expectantly,a negative exploratory laparotomy and its associated risks are avoided.

Recurrent tense pneumoperitoneum due to air influx via abdominal wall stoma of a PEG tube

A 70 years old male on ventilatory and circulatory support for sepsis and non ST segment elevation myocardial infarction developed abdominal distension 14 d after placement of a percutaneous endoscopic gastrostomy tube for enteral feeding.Radiography revealed free air in the abdomen and gastrograffin(G) study showed no extravasation into the peritoneum.The G tube was successfully repositioned with mechanical release of air.Imaging showed complete elimination of free air but the patient had a recurrence of pneumoperitoneum.Mechanical release of air with sealing of the abdominal wound was performed.Later,the patient was restarted on tube feeding with no complications.This case demonstrates a late complication of pneumoperitoneum with air leakage from the abdominal wall stoma.

Pneumatosis intestinalis and pneumoperitoneum on computed tomography:Beware of non-therapeutic laparotomy

Pneumatosis intestinalis(PI) is defined as gas within the gastrointestinal wall and is associated with a variety of disorders.As a concurrent occurrence with pneumoperitoneum,it can easily to be mistaken for bowel ischemia with perforated peritonitis.In fact,air dissection or rupture from subserosal cysts may be the cause of intraperitoneal and intraluminal free air,with clinical symptoms such as abdominal pain and fullness occurring as a result.We hereby report a case of an 82-year-old male with a history of chronic obstructive pulmonary disease who was diagnosed with bowel ischemia and received emergency laparotomy because of the appearance of PI and pneumoperitoneum on abdominal computed tomography scan.However,no perforated hollow organ or necrotic bowel segment was found,only diffusely distributed massive intraperitoneal air and PI of gastrointestinal tract.The laparotomy seemed non-therapeutic for this patient.This is significant warning for clinicians to differentiate the associated conditions of PI,and to evaluate whether or not emergency surgery is necessary.

Uncommon cause of pneumoperitoneum

Free intraperitoneal air is thought to be pathognomonic for perforation of a hollow viscus. Here, we present a patient with pain in the upper left quadrant, a mild fever and leukocytosis. Free air was suggested under the left diaphragm but during the explorative laparotomy no signs of gastric or diverticular perforation were seen. Further exploration and revision of the computed tomography revealed a perforated splenic abscess. Splenic abscesses are a rare clinical entity. Presenting symptoms are often non-specific and include upper abdominal pain, recurrent or persistent fever, nausea and vomiting, splenomegaly, leukocytosis and left lower chest abnormalities. Predisposing conditions can be very divergent and include depressed immunosuppressed state, metastatic or contiguous infection, splenic infarction and trauma. Splenic abscess should therefore be considered in a patient with fever, left upper abdominal pain and leukocytosis. Moreover, our case shows that splenic abscess can present in an exceptional way without clear underlying aetiology and should even be considered in the presence of free abdominal air.

A Rare Cause of Pneumoperitoneum: Perforated Gastrointestinal Stromal Tumor (GIST)

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor and has a malignant potential. The clinical presentation with pneumoperitoneum and peritonitis is extremely rare. We report a case of a 40-year-old male presented with symptoms of acute abdomen. Radiological work-up confirmed pneumoperitoneum. Emergency laparatomy and complete resection were performed. The final diagnosis revealed perforated GIST originating from the jejunum. If an abdominal mass presents with pneumoperitoneum and peritonitis, jejunal GIST should be considered in diagnosis. A complete radical resection followed by postoperative adjuvant chemotheraphy with Imatinib is recommended.

Effects of carbon dioxide pneumoperitoneum on metastasis of ovarian carcinoma cell line SKOV_3

The long suspicion of the potential harm of carbon dioxide （CO2） pneumoperitoneum exists in laparoscopic cancer surgery. For better understanding of this problem, we targeted this study at the effects of CO2 pneumoperitoneum on the invasive ability of ovarian carcinoma cell line and the possible mechanism within it. To study the effects of CO2 pneumoperitoneum on carcinoma cell, SKOV3 cells were divided into 2 groups, respectively exposed to pneumoperitoneal CO2-insuffiation and normal conditions. To study the possible mechanism, SKOV3 cells were divided into 3 groups, one was exposed to CO2 pneumoperitoneum, one to N2 and the other to normal conditions served as control. The in vitro adhesive and invasive ability of the cells was analyzed through 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay and Boyden filters metastasis model; the expressions of vascular endothelial growth factor C （VEGF-C） and matrix metalloproteinase 9 （MMP9） were determined by reverse transcription polymerase chain reaction（RT-PCR）, and Western blot. We found that the adhesive ratio of SKOV3 cells exposed to CO2 was significantly higher than that of the control group; cells exposed to CO2 invaded the matrigel with a greater number （P〈0.01）; the expression of VEGF-C exposed to both CO2 and N2 was significantly increased compared with control group （P〈0.05）; the MMP9 expression level of CO2 group was higher than that of N2 group, P〈0.05. We concluded that carbon dioxide pneumoperitoneum may improve the adhesive and invasive ability of ovarian carcinoma cell line in vitro and CO2 can also be an independent factor to stimulate the expression of MMP9.

Massive Idiopathic Pneumoperitoneum in Children: A Case Report

The pneumoperitoneum is the abnormal presence of free air in the peritoneal cavity. In most cases it is related to the perforation of hollow organs. Nevertheless there are cases of pneumoperitoneum without obvious causes called idiopathic. We report a case of massive pneumoperitoneum of radiological discovery in a patient of 16 years old boy, sickle-cell of type SS, during the exploration of an angiocholitis. It was medically treated successfully. No obvious etiology had been found. This particular situation is a dogma which runs up against the classic interventionist spirit;therefore each of pneumoperitoneum needs to be studied case by case. The presence of signs of peritoneal irritation allows surgical exploration. Otherwise, laparoscopy seems to be a minimally invasive surgical method and allows a visual diagnosis by eliminating a hollow organ perforation.

Laparoscopic Trainer with Pneumoperitoneum

The development of skills and abilities in laparoscopy is directly related to the use of trainers. The trainer should model the patient with all its natural complexities as closely as possible. In this article we propose a system for training the establishment of pneumoperitoneum executing the basic tasks to create the workspace in the trainer, the insertion of primary umbilical trocar and simulate some of the everyday problems in surgery. Materials and Methods. A group of electrical with biomedical engineers and laparoscopic surgeons developed a physical trainer that allows implementing the pneumoperitoneum. The system uses pneumatic electro valves that are controlled with a dedicated microprocessor. The user can program the system to set the parameters of the pneumoperitoneum. Results. This new trainer facilitated the programming of right values of parameters to distend the abdominal cavity according a specific clinical case. The model developed enables the trainee to consolidate his knowledge on establishing the parameters required within clinical practice, as well as the entry techniques. Conclusions. A new physical model for laparoscopic training was designed. The system enables the laparoscopic surgeon to set the parameters for establishing the workspace according to the clinical case. The trainer allows the surgeon to train in the Hasson technique for the introduction of the first trocar, as well as the placement of the rest of surgical instruments with video assistance. We think this new trainer system will help minimize entry-related injuries.

Progressive pre-operative pneumoperitoneum is not necessary for large inguinoscrotal hernia repair: Report of a case

Huge inguinoscrotal hernias are a challenging operation. The technical aspects of the procedure can be very difficult and the recovery may be complicated by ventilatory problems. Progressive preoperative pneumoperitoneum (PPP) is a method which has been used for many years to reduce both intra and postoperative complications. However, it is associated with a prolonged preoperative hospital stay which is expensive and often stressful to patients. We report a case of a morbidly obese patient with a huge inguinoscrotal hernia. PPP was not implemented. The operation was uneventful and he was discharged 8 days later with no major post-operative complications. This case therefore questions the necessity of PPP for huge inguin- oscrotal hernias.

Effects of suspension laparoscopy and pneumoperitoneum laparoscopic surgery on ovarian function, inflammatory response and stress hormone in patients with ovarian cystectomy

Objective:To investigate the effects of suspension laparoscopy and pneumoperitoneum laparoscopic surgery on inflammatory response, stress hormone and ovarian function in patients with ovarian cystectomy.Methods: Retrospective analysis of the data of laparoscopic ovarian cyst denudation in our hospital from July 2015 to August 2017, and they were were divided into the control group and the treatment group according to the surgical methods they accepted. The levels of inflammatory factors and stress hormone preoperative and postoperative 24 h, and ovarian function of the menstrual period 3rd day preoperative and postoperative 3 months of the two groups were compared.Results: There was no significant difference in the levels of TNF-α, CRP, COR, NE, E2, LH and FSH between the two groups before the operation. Postoperative 24 h, the levels of TNF-α, CRP, COR and NE in the treatment group were significantly lower than those in the control group, and the level of E2 in the treatment group was higher than that in control group, the levels of LH and FSH in the treatment group were lower than those in control group postoperative 3 months, the difference were statistically significant.Conclusion: Compared with pneumoperitoneum laparoscopic surgery, suspended laparoscopic surgery can effectively reduce the inflammatory response, reduce the level of stress hormone and improve ovarian function in patients undergoing ovarian cystectomy, which has a certain clinical value.

The effects of CO_2 pneumoperitoneum on tumor growth in vivo

Objective:The aim of this study is to evaluate the effect of CO_2 pneumoperitoneum on growth and spread of intraperitoneal tumor in an animal model.Methods:We established an animal model of epithelial ovarian cancer in immunocompetent rat Fischer 344.Twenty rats were randomized to two groups(10rats /group):CO_2 insufflation and sham laparotomy.Tumors were excised from the rats in each group 28 days after operation.Ascites,tumor mass,local regional invasion incidence,lymph node involvement,and liver and lung metastases were evaluated.Sections of tumors were made and then the cell cycle fraction were measured by quantitating DNA in individual cells using flow cytometry analysis.The expressions of Ki-67,VEGF,and CD44v6 protein were determined using immunocytochemistry by flow cytometry.Results:Tumor mass,local regional invasion incidence and the amount of ascites were higher in CO_2 insufflation than those in laparotomy,but there were no significant differences between two groups.The expression of CD44v6 protein was higher in CO_2 insufflation than that in laparotomy(P=0.002).There was no significant difference between two groups in the cells cycle fraction and the expressiones of Ki-67 and VEGF protein.Conclusions:CO_2 pneumoperitoneum has effects on intraperitoneal tumor growth and metastasis in the animal model.