Influence of different gases used for laparoscopy (helium, carbon dioxide, room air, and xenon) on tumor volume, histomorphology, and leukocyte-tumor-endothelium interaction in intravital microscopy

Ultrasound Responsive Noble Gas Microbubbles for Applications in Image-Guided Gas Delivery

Noble gases, especially xenon (Xe), have been shown to have antiapoptotic effects in treating hypoxia ischemia related injuries. Currently, in vivo gas delivery is systemic and performed through inhalation, leading to reduced efficacy at the injury site. This report provides a first demonstration of the encapsulation of pure Xe, Ar, or He in phospholipid-coated sub-10 µm microbubbles, without the necessity of stabilizing perfluorocarbon additives. Optimization of shell compositions and preparation techniques show that distearoylphosphatidylcholine (DSPC) with DSPE-PEG5000 can produce stable microbubbles upon shaking, while dibehenoylphosphatidylcholine (DBPC) blended with either DSPE-PEG2000 or DSPE-PEG5000 produces a high yield of microbubbles via a sonication/centrifugation method. Xe and Ar concentrations released into the microbubble suspension headspace are measured using GC-MS, while Xe released directly in solution is detected by the fluorescence quenching of a Xe-sensitive cryptophane molecule. Bubble production is found to be amenable to scale-up while maintaining their size distribution and stability. Excellent ultrasound contrast is observed in a phantom for several minutes under physiological conditions, while an intravenous administration of a bolus of pure Xe microbubbles provides significant contrast in a mouse in pre- and post-lung settings (heart and kidney, respectively), paving the way for image-guided, localized gas delivery for theranostic applications.

Intestinal metastasis after total laparoscopic radical trachelectomy for stage IB1 cervical cancer: A case report

•Simultaneous sigmoid colon and rectum metastasis after LRT.•Caution should be exercised in expanding conventional indications in fertility preserving surgery.•Cervical tumor exposure to CO2 should be avoided during surgery.

Prolonged helium postconditioning protocols during early reperfusion do not induce cardioprotection in the rat heart in vivo: role of inflammatory cytokines

Postconditioning of myocardial tissue employs short cycles of ischemia or pharmacologic agents during early reperfusion. Effects of helium postconditioning protocols on infarct size and the ischemia/reperfusion-induced immune response were investigated by measurement of protein and mRNA levels of proinflammatory cytokines. Rats were anesthetized with S-ketamine (150 mg/kg) and diazepam (1.5 mg/kg). Regional myocardial ischemia/reperfusion was induced; additional groups inhaled 15, 30, or 60 min of 70% helium during reperfusion. Fifteen minutes of helium reduced infarct size from 43% in control to 21%, whereas 30 and 60 minutes of helium inhalation led to an infarct size of 47% and 39%, respectively. Increased protein levels of cytokine-induced neutrophil chemoattractant (CINC-3) and interleukin-1 beta (IL-1β) were found after 30 or 60 min of helium inhalation, in comparison to control. 30 min of helium increased mRNA levels of CINC-3, IL-1β, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) in myocardial tissue not directly subjected to ischemia/reperfusion. These results suggest that the effectiveness of the helium postconditioning protocol is very sensitive to duration of noble gas application. Additionally, helium was associated with higher levels of inflammatory cytokines; however, it is not clear whether this is causative of nature or part of an epiphenomenon.

Laparoscopy for colorectal cancer

The laparoscopic approach for colorectal cancer resection has been evolved from an experimental procedure with oncological concerns to routine daily practice within a period of two decades. Numerous randomized controlled trials and meta-analyses have shown that laparoscopic resection results in faster recovery with similar oncological outcome compared to an open approach, both for colon and rectal cancer. Besides improved cosmesis, other long-term advantages seem to be less adhesion related small bowel obstruction and reduced incisional hernia rate. Adequate patient selection and surgical experience are of crucial importance. Experience can be gradually expanded step by step, by increasing the complexity of the procedure. A decision to convert should be made early in the procedure, because the outcome after a reactive conversion is worse than initial open resection or strategic conversion. The additive value of new techniques such as robotic surgery has to be proven in randomized studies including a cost-effectiveness assessment.

The addition of 4% oxygen to the CO(2) pneumoperitoneum does not decrease dramatically port site metastases

STUDY OBJECTIVE

Port site metastases (PSM) after laparoscopic surgery for advanced-stage ovarian carcinoma are a cause of concern, but the pathophysiology is unknown. Because CO(2) pneumoperitoneum was recently demonstrated to be a cofactor in adhesion formation and tumor implantation in a laparoscopic mouse model, and because both could be prevented by the addition of 4% oxygen to the CO(2) pneumoperitoneum, we wanted to test the hypothesis that PSM could be related to tumor cell hypoxia during CO(2) pneumoperitoneum.

DESIGN

A randomized controlled pilot trial to compare the incidence of PSM in women undergoing laparoscopy with a pure CO(2) pneumoperitoneum in comparison with women with CO(2) pneumoperitoneum with the addition of 4% oxygen (Canadian Task Force classification C).

SETTING

University Hospital Gasthuisberg, Leuven, Belgium.

PATIENTS

Since January 1, 2007, 22 consecutive women undergoing laparoscopy for suspected ovarian cancer with subsequent debulking laparotomy were included.

INTERVENTIONS

Diagnostic laparoscopy with 100% CO(2) versus laparoscopy with addition of 4% oxygen.

MEASUREMENTS AND MAIN RESULTS

In the control group, 9 (47%) PSM found in 19 port sites were excised. In the CO(2)+oxygen group, a similar incidence was found, that is, 8 (50%) PSM in 16 port sites. The incidence of PSM was higher in small women (p <.018) and in high-grade malignancies. The pathophysiology of PSM is unknown, but besides direct wound contamination, aerosolization of tumor cells and gas leaks have been suggested together with a causal relationship with the CO(2) pneumoperitoneum. Tumor cell hypoxia probably is not an important mechanism because PSM were not prevented by adding small amounts of oxygen to the CO(2) pneumoperitoneum.

CONCLUSION

The hypothesis of tumor cell hypoxia by the CO(2) pneumoperitoneum as a mechanism for PSM could not be confirmed.

Cœlioscopie et cancer en gynécologie : le point en 2005

All the surgical procedures, which may be required to treat a gynecologic cancer, can be performed endoscopically. However prospective randomized studies required to confirm the oncologic efficacy of the technique are still lacking in gynecology, whereas such studies are available in digestive surgery. Animal studies suggested that the risk of tumor dissemination in non traumatized peritoneum is higher after a pneumoperitoneum than after a laparotomy. Experimental studies also emphasized two points: the surgeon and the surgical technique are essential, all the parameters of the pneumoperitoneum may influence the postoperative dissemination. Changing these parameters we may, in the future, be able to create a peritoneal environment adapted to oncologic patients in order to prevent or to decrease the risks of peritoneal dissemination and/or of postoperative tumor growth. Until the results of prospective randomized studies become available, the preoperative selection of the patients and the surgical technique should be very strict. In patients with endometrial cancer, the laparoscopic approach should be reserved to clinical stage I disease, if the vaginal extraction is anticipated to be easy accounting for the volume of the uterus and the local conditions. In cervical cancer, the laparoscopic approach should be reserved to patients with favorable prognostic factors: stage IB of less than 2 cm in diameter. Laparoscopy is the gold standard for the surgical diagnosis of adnexal masses. But the puncture should be avoided whenever possible. The surgical treatment of invasive ovarian cancer should be performed by laparotomy whatever the stage. In contrast restaging of an early ovarian cancer initially managed as a benign mass, is a good indication of the laparoscopic approach. The laparoscopic management of low malignant potential tumors should include a complete staging of the peritoneum. Knowledge of the principles of endoscopy and of oncologic surgery is required. Teaching and diffusion of endoscopic oncological techniques are among the major challenges of gynecologic surgery within the next few years.