Masashi Fujioka

Pneumoperitoneum with carbon dioxide enhances liver metastases of cancer cells implanted into the portal vein in rabbits

AbstractBackground: Little is known about the role of the CO2 pneumoperitoneum on tumor cells that spread from the portal system into the liver during laparoscopic surgery for gastrointestinal malignancies. Therefore, we designed a study to investigate the effect of CO2 pneumoperitoneum on cancer cells implanted in the portal vein in a rabbit model. Methods: Immediately after intraportal inoculation of 2.5 × 105 cells of VX2 cancer, the rabbits received either CO2 pneumoperitoneum at a pressure of 10 mmHg for 30 min (pneumoperitoneum group, n= 14) or laparotomy alone for 30 min (laparotomy group, n= 14). Results: The number (p < 0.01) and area of cancer nodules (p= 0.045) on the liver surface on day 17 were greater in the pneumoperitoneum group than in the laparotomy group. The frequency of cancer nodules >3.0 mm in diameter was higher in the pneumoperitoneum group than in the laparotomy group (p < 0.001). Conclusions: Compared with laparotomy, CO2 pneumoperitoneum enhanced the development of liver metastases in this experimental model.

Influence of trocar placement and CO2 pneumoperitoneum on port site metastasis following laparoscopic tumor surgery

AbstractBackground: The mechanisms involved in the development of port site metastasis following laparoscopic tumor surgery remain controversial. Therefore, we decided to investigate the influence of trocar placement and CO2 pneumoperitoneum on abdominal wound implantation in relation to intraperitoneal tumor growth in a rabbit model. Methods: Rabbits received either CO2 pneumoperitoneum with insertion of nine trocars (pneumoperitoneum group, n= 15), insertion of nine trocars alone (nonpneumoperitoneum group, n= 15), or nine abdominal incisions (control group, n= 13) 3 days after intraperitoneal inoculation of VX2 cancer cells. Results: The frequency of overall wound implantation on day 17 in the pneumoperitoneum group (24.4%) and nonpneumoperitoneum group (27.4%) tended to be higher than that in the control group (15.3%) (p= 0.06). There was no significant difference among the three groups in the growth of cancer nodules on the omentum. Conclusions: The presence of a trocar may be a factor contributing to port site metastasis but CO2 pneumoperitoneum appears not to be a factor.

Laparoscopic gastropexy for acute gastric volvulus: A case report

A 7-year-old girl presented with an acute gastric volvulus that was reduced with a nasogastric catheter. An anterior gastropexy was undertaken laparoscopically. The gastrocolic omentum was deficient along most of the greater curvature, which had allowed organoaxial volvulus. Two years later, gastric volvulus has not recurred. Laparoscopy is an acceptable approach for the evaluation and treatment of children with acute gastric volvulus.

Effect of CO2 Pneumoperitoneum on Growth of Liver Micrometastases in a Rabbit Model

Little is known about the risk of metachronous liver metastases following laparoscopic resection for gastrointestinal malignancies. The effect of CO2 pneumoperitoneum on the growth of established liver micrometastases was investigated in a rabbit model. Male Japanese white rabbits weighing 2.8 to 3.3 kg were randomized to three groups (n= 15 per group) 3 days following intraportal inoculation of a tumor suspension containing 5 × 104 cells of VX2 cancer. In the pneumoperitoneum group, insufflation with CO2 was maintained at a pressure of 10 mmHg for 30 minutes. In the laparotomy group the abdominal cavity remained open through a 45 mm midline incision for 30 minutes; in the control group no treatment other than anesthesia was performed. Cancer nodules on the liver surface were compared among the three groups on day 17. There was no difference in the number of cancer nodules among the groups (p= 0.72). A significant difference in the total area of cancer nodules (mean ± SEM) was found only between the pneumoperitoneum group (696.0 ± 177.0 mm2) and the control group (247.2 ± 60.7 mm2) (p < 0.05). The frequency of cancer nodules larger than 3.0 mm in maximal diameter tended to be highest in the pneumoperitoneum group (p= 0.053). These results suggests that CO2 pneumoperitoneum may promote the growth of established liver micrometastases in this animal model.

Liver metastasis following pneumoperitoneum with different gases in a mouse model

BackgroundThe validity of using CO2 in laparoscopic tumor surgery has not yet been established. To address this question, we investigated the growth of liver metastases following insufflation with different gases in a mouse laparoscopy model.MethodsMale BALB/C mice inoculated intraportally with colon 26 cells were randomized to undergo pneumoperitoneum with CO2 (n=16), helium (n=16), argon (n=16), or air (n=17), or to act as controls without insufflation (n=17).ResultsThe growth of cancer nodules on the liver 14 days after surgery was greater in mice following insufflation with CO2 (p<0.01), helium (p<0.01), argon (p=0.01), and air (p=0.07) than in control mice. No significant differences were found between the four insufflation groups in the growth of liver metastases.ConclusionThese results suggest that insufflation plays an important role in the development of liver metastases but that the choice of gas may not affect their growth.

The influence of different insufflation pressures during carbon dioxide pneumoperitoneum on the development of pulmonary metastasis in a mouse model

AbstractBackground: The effects of different insufflation pressures on the development of pulmonary metastasis was investigated in a mouse laparoscopy model. Methods: BALB/C mice intravenously inoculated with colon 26 cells were randomized to one of five treatment groups (10 mice per group): pneumoperitoneum at different pressures of 5, 10 or 15 mmHg; full laparotomy for 60 min; or anesthesia control. Cancer nodules on the lung surface 19 days postoperatively were compared between groups. Results: (a) As compared with the control group, pneumoperitoneum at 10 and 15 mmHg and laparotomy enhanced the growth of pulmonary metastases (p < 0.01). (b) The growth of metastases also was greater in laparotomy group mice than in mice undergoing pneumoperitoneum at 5 and 10 mmHg (p < 0.05). Conclusions: These results suggest that the effects of different insufflation pressures on the growth of pulmonary metastases are not identical, and that pneumoperitoneum with high pressure may promote pulmonary metastases similar to those with laparotomy.

Immunogenicity and Reactogenicity of a Monovalent Inactivated 2009 Influenza A Vaccine in Adolescents: With Special Reference to Pre-Existing Antibody

OBJECTIVE To evaluate the immunogenicity and reactogenicity of a monovalent 2009 pandemic influenza vaccine in Japanese adolescents. STUDY DESIGN A total of 111 junior high school and high school students aged 13 to 18 years participated. Subjects received two doses of a monovalent inactivated unadjuvanted 2009 influenza A vaccine. Immunogenicity of the vaccine was evaluated according to the international criteria. We also asked subjects to report adverse reactions. RESULTS After the first dose of vaccine, the seroprotection rate was 91% (95% CI, 85%-96%), the seroconversion rate was 78% (70%-86%), and the geometric mean titer ratio was 11.9 in all subjects. Antibody titers achieved did not differ significantly after the first and the second doses. With multivariate analysis, an independent negative effect of a prevaccination titer of ≥1:40 on ≥4 fold antibody increase was indicated. No serious adverse reaction was reported. CONCLUSION The monovalent pandemic vaccine generally was safe, and a single dose of the vaccine given to adolescents induced sufficient immunity. Pre-existing antibody showed substantial effect on antibody response. The effect of pre-existing titer should be considered when evaluating the immunogenicity of influenza vaccines, especially in studies conducted during pandemic waves.

A New Simple Technique for Performing Intraoperative Endoscopic Resection of Small-Bowel Polyps in Patients with Peutz-Jeghers Syndrome

We describe herein a simple method for performing intraoperative endoscopic resection of small-bowel polyps associated with Peutz-Jeghers syndrome, using a corrugated anesthetic tube. A 34-year-old man with Peutz-Jeghers syndrome underwent emergency surgery for an ileo-ileo-colic intussusception. A sterile corrugated anesthetic tube was inserted into the small-bowel, proximal to the affected lesion. The small bowel was then telescoped sequentially over the tube using a pleating technique. Consequently, a colonoscope inserted through the tube was easily able to reach the duodeno-jejunal junction, and ten small-bowel polyps were removed using a wire snare and electrocauterization. All resected specimens were washed out by the instillation of saline through a nasogastric tube, then collected on gauze placed near the outlet of the tube. Our technique has the following merits: it is feasible even in emergency surgery; it prevents contamination of the surgical field; and it facilitates the easy collection of polypectomized specimens.

Usefulness of Postoperative Spiral Computed Tomography Combined with Drip Infusion Cholangiography in Patients with Congenital Biliary Dilatation.

近年, 経静脈性胆道造影 (drip infusion cholangiography) 併用下のspiral computed tomography (以下, DIC-SCT) が, 胆道系疾患の新しい非侵襲検査として普及した. そこで今回, 先天性胆道拡張症術後症例におけるDIC-SCTの有用性について検討を行った.先天性胆道拡張症の診断で, 以前に胆嚢・拡張胆管切除, 肝管腸吻合術を施行した7例を対象にDIC-SCTを行った. 手術時の年齢は, 4か月～40歳2か月で, 術後の経過観察期間は, 1年6か月～10年7か月であった.全例において, 肝内胆管1次分枝, 吻合部, および吻合部以下の腸管が描出され, 吻合部の横径は4mm～25mm, 前後径は3mm～20mmと測定できた. IV-A型の1例では, 右枝に拡張を認め, 左枝は描出されなかった.DIC-SCTは, 先天性胆道拡張症術後症例における吻合部の形態や胆汁うっ滞の有無を簡便に知る方法として優れていた.