Impact of surgical peritoneal environment on postoperative tumor growth and dissemination in a preimplanted tumor model

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Modes of carbon dioxide delivery during laparoscopy generate distinct differences in peritoneal damage and hypoxia in a porcine model

BACKGROUND

Insufflation with CO₂ can employ continuous flow, recirculated gas and/or additional warming and humidification. The ability to compare these modes of delivery depends upon the assays employed and opportunities to minimize subject variation. The use of pigs to train colorectal surgeons provided an opportunity to compare three modes of CO₂ delivery under controlled circumstances.

METHODS

Sixteen pigs were subjected to rectal resection, insufflated with dry-cold CO₂ (DC-CO₂) (n = 5), recirculated CO₂ by an AirSeal device (n = 5) and humidification and warming (HW-CO2) by a HumiGard device (n = 6). Peritoneal biopsies were harvested from the same region of the peritoneum for fixation for immunohistochemistry for hypoxia-inducible factor 1 alpha (HIF-1α) and scanning electron microscopy (SEM) to evaluate hypoxia induction or tissue/cellular damage, respectively.

RESULTS

DC-CO₂ insufflation by both modes leads to significant damage to mesothelial cells as measured by cellular bulging and retraction as well as microvillus shortening compared with HW-CO₂ at 1 to 1.5 h. DC-CO₂ also leads to a rapid and significant induction of HIF-1α compared with HW-CO₂.

CONCLUSIONS

DC-CO₂ insufflation induces substantive cellular damage and hypoxia responses within the first hour of application. The use of HW-CO₂ insufflation ameliorates these processes for the first one to one and half hours in a large mammal used to replicate surgery in humans.

Rapid exacerbation featuring acute leukemoid reaction after retrolaparoscopic nephrectomy: a rare case report of renal cell carcinoma with postoperative comprehensive genomic profiling

Background

Rapid lethal exacerbation and recurrence featuring acute leukemoid reaction (ALR) after retrolaparoscopic radical nephrectomy (RN) is a relatively rare clinical incident. Performing the reoperation for the patient and analyzing the tissue-based genetic mutation information postoperatively are a skill-demanding and meaningful task, which have been even more rarely reported.

Case presentation

We present a case with a large right renal mass (13.0 × 10.0 × 8.0 cm). This 71-year-old male patient underwent the retrolaparoscopic RN in our department. The operation was technically precise and successful with final pathological diagnosis of hybrid (clear cell and papillary type) renal cell carcinoma (RCC). However, 10 days after the patient was discharged, he was readmitted with the chief complaint of high fever with severe right flank pain. CT scanning revealed that right retroperitoneal hematoma and the blood routine showed the dramatic elevation of white blood cell count (WBC). Even though the immediate broad-spectrum antibiotics were administered without delay and subsequent percutaneous puncturing and drainage was performed, the patient’s condition still exacerbated rapidly. In spite of the reoperation of hematoma evacuation, the patient died of multiple organ failure 10 days after the reoperation. The pathological result of reoperation showed the necrotic and hematoma tissue blended with RCC tumor cells (nuclear grading III), and both of the postoperative tissue-originated comprehensive genomic profiling by using the specimens from the RN and reoperation respectively indicated significant mutations of some oncogenes which might have potential relevance with ALR. Besides, both of the immunohistochemical (IHC) staining results from primary surgical renal mass and reoperative resected tissue revealed the positive expressions of granulocyte colony-stimulating factor (G-CSF).

Conclusions

ALR may be a predictor of poor prognosis in patients with RCC, and comprehensive genomic profiling as well as the alterative expression of G-CSF can help to provide potential valuable genetic etiological information and evidence for guiding the potential effective molecular-targeting therapy.

Surgical peritoneal stress creates a pro-metastatic niche promoting resistance to apoptosis via IL-8

Background

The mainstay of treatment of advanced ovarian cancer (AOC) involves chemotherapy, and debulking surgery. However, despite optimal surgical procedure and adjuvant chemotherapy, 60% of patients with AOC will relapse within 5 years. Most recurrences occur in the peritoneal cavity, suggesting the existence of occult sanctuaries where ovarian cancer cells (OCC) are protected. In murine models, surgical stress favors tumor growth; however, it has never been established that surgery may affect OCC sensitivity to subsequent chemotherapy. In this study, we investigated how the surgical stress could affect the chemosensitivity of OCC.

Methods

To avoid bias due to tumor burden in peritoneal cavity and duration of surgery, we used peritoneal biopsies from patients without a malignancy at precise time points. During laparotomies, peritoneal biopsies at the incision site were performed at the time of incision (H0 sample) and 1 h after initiation of surgery (H1 sample). We evaluated the chemoresistance to Taxol (0–20 µM) induced by H0 or H1 incubation (24 h) in two ovarian cancer cell lines OVCAR3 and SKOV3 and a primary cancer cell lines derived in our laboratory.

Results

Our results indicate that stressed peritoneum overexpressed cytokines, resulting in OCC increased resistance to therapy. Among these cytokines, IL8 was responsible for the resistance to apoptosis through the AKT pathway activation. Chemoresistance in OCC persists through the establishment of an autocrine IL8 loop. Finally, in a cohort of 32 patients, we showed an impact of IL8 tumoral overexpression on chemosensitivity and survival outcomes with a significant association to earlier recurrence.

Conclusions

Our study demonstrated that precision surgery where targeted treatment would be used in combination with surgery is essential to obtain better tumor control.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1643-z) contains supplementary material, which is available to authorized users.

Experimental study of delivery of humidified-warm carbon dioxide during open abdominal surgery

Background

The aim of this study was to monitor the effect of humidified‐warm carbon dioxide (HWCO₂) delivered into the open abdomen of mice, simulating laparotomy.

Methods

Mice were anaesthetized, ventilated and subjected to an abdominal incision followed by wound retraction. In the experimental group, a diffuser device was used to deliver HWCO₂; the control group was exposed to passive air flow. In each group of mice, surgical damage was produced on one side of the peritoneal wall. Vital signs and core temperature were monitored throughout the 1‐h procedure. The peritoneum was closed and mice were allowed to recover for 24 h or 10 days. Tumour cells were delivered into half of the mice in each cohort. Tissue was then examined using scanning electron microscopy and immunohistochemistry.

Results

Passive air flow generated ultrastructural damage including mesothelial cell bulging/retraction and loss of microvilli, as assessed at 24 h. Evidence of surgical damage was still measurable on day 10. HWCO₂ maintained normothermia, whereas open surgery alone led to hypothermia. The degree of tissue damage was significantly reduced by HWCO₂ compared with that in controls. Peritoneal expression of hypoxia inducible factor 1α and vascular endothelial growth factor A was lowered by HWCO₂. These effects were also evident at the surgical damage sites, where protection from tissue trauma extended to 10 days. HWCO₂ did not reduce tumorigenesis in surgically damaged sites compared with passive air flow.

Conclusion

HWCO₂ diffusion into the abdomen in the context of open surgery afforded tissue protection and accelerated tissue repair in mice, while preserving normothermia.

What is the evidence for the use of low-pressure pneumoperitoneum? A systematic review

Background

Laparoscopic surgery has several advantages when compared to open surgery, including faster postoperative recovery and lower pain scores. However, for laparoscopy, a pneumoperitoneum is required to create workspace between the abdominal wall and intraabdominal organs. Increased intraabdominal pressure may also have negative implications on cardiovascular, pulmonary, and intraabdominal organ functionings. To overcome these negative consequences, several trials have been performed comparing low- versus standard-pressure pneumoperitoneum.

Methods

A systematic review of all randomized controlled clinical trials and observational studies comparing low- versus standard-pressure pneumoperitoneum.

Results and conclusions

Quality assessment showed that the overall quality of evidence was moderate to low. Postoperative pain scores were reduced by the use of low-pressure pneumoperitoneum. With appropriate perioperative measures, the use of low-pressure pneumoperitoneum does not seem to have clinical advantages as compared to standard pressure on cardiac and pulmonary function. Although there are indications that low-pressure pneumoperitoneum is associated with less liver and kidney injury when compared to standard-pressure pneumoperitoneum, this does not seem to have clinical implications for healthy individuals. The influence of low-pressure pneumoperitoneum on adhesion formation, anastomosis healing, tumor metastasis, intraocular and intracerebral pressure, and thromboembolic complications remains uncertain, as no human clinical trials have been performed. The influence of pressure on surgical conditions and safety has not been established to date. In conclusion, the most important benefit of low-pressure pneumoperitoneum is lower postoperative pain scores, supported by a moderate quality of evidence. However, the quality of surgical conditions and safety of the use of low-pressure pneumoperitoneum need to be established, as are the values and preferences of physicians and patients regarding the potential benefits and risks. Therefore, the recommendation to use low-pressure pneumoperitoneum during laparoscopy is weak, and more studies are required.

Effect of carbon dioxide pneumoperitoneum on human renal cell carcinoma proliferation and metastasis in an orthotropic xenograft nude mouse model

INTRODUCTION

This study aimed to explore the effect of carbon dioxide (CO2) pneumoperitoneum on tumor proliferation and metastasis in an orthotropic xenograft nude mice model of human renal cell carcinoma (RCC) and evaluate the safety of CO2 pneumoperitoneum laparoscopy for treating RCC.

MATERIAL AND METHODS

RCC 786-0 cells were injected to establish an orthotropic xenograft model. Fifty nude mice were given orthotropic inoculations and randomized to five groups: group A (control); group B (CO2 pneumoperitoneum for 2 h); group C (CO2 pneumoperitoneum for 4 h); group D (CO2 pneumoperitoneum for 4 h and 24 h after waking); group E (CO2 pneumoperitoneum for 4 h and 48 h after waking). The proliferation status was observed in RCC specimens by immunohistochemical staining for Ki67. The protein levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were examined by western blotting.

RESULTS

All groups showed similar Ki67-positive staining in RCC samples (p > 0.05). The relative expression of HIF-1α and VEGF gradually increased in both group B and group C, as compared with group A, but only the difference between group C and group A reached statistical significance (p < 0.05). The protein levels of HIF-1α and VEGF decreased in both group D and group E, as compared with group B and group C; however, the differences between group D, group E, and group A did not reach statistical significance (p > 0.05).

CONCLUSIONS

In an orthotropic xenograft nude mice model of RCC, CO2 pneumoperitoneum has no effect on expression of the cellular proliferation marker Ki67. However, CO2 pneumoperitoneum rapidly induces transient expression of HIF-1α and VEGF. Thus, CO2 pneumoperitoneum laparoscopy may be a safe method for treating RCC.

Lethal effect of a hyperthermic CO₂ pneumoperitoneum on gastric cancer cells

OBJECTIVES

We investigated the lethal effect of a hyperthermic CO₂ pneumoperitoneum on gastric cancer cells. This could form the theoretical basis for further studies of the feasibility and safety of inflating hyperthermic CO₂ in the abdominal cavity of gastric cancer patients during laparoscopy.

METHODS

An in vitro hyperthermic CO₂ pneumoperitoneum experimental model was built, where gastric cancer cell line SGC-7901 cells were grouped according to temperature. Cytotoxicity was detected using a cell counting kit; apoptosis was detected by Annexin V-FITC/PI flow cytometry and Hoechst 33342/PI fluorescent microscopy. Morphological alterations were observed by transmission electron microscopy. Invasion and migration were detected by a scratch test and by transwell migration, respectively.

RESULTS

Cytotoxicity assays showed that a hyperthermic CO₂ pneumoperitoneum significantly inhibited the proliferation of SGC-7901 cells (P<0.05); it also significantly induced apoptosis of SGC-7901 cells (P<0.05). Morphological observations showed that the cell membrane and nucleus had an apoptotic phenotype. The invasiveness and migration ability of the gastric cancer cells subjected to hyperthermic CO₂ were significantly reduced.

CONCLUSIONS

A hyperthermic CO₂ pneumoperitoneum had a lethal effect on gastric cancer SGC-7901 cells by inhibiting their invasion and migration, and by inducing apoptosis.

Impact of intraperitoneal pressure and duration of surgery on levels of tissue plasminogen activator and plasminogen activator inhibitor-1 mRNA in peritoneal tissues during laparoscopic surgery

BACKGROUND

Our objective was to evaluate the impact of intraperitoneal pressure (IPP) and duration of a CO(2) pneumoperitoneum on the peritoneal fibrinolytic system during laparoscopic surgery.

METHODS

Human study: Patients undergoing laparoscopic surgery were divided into two groups: low (8 mmHg, n= 32) or standard (12 mmHg, n= 36) IPP. Normal peritoneum was collected from the parietal wall at the beginning of surgery and every 60 min thereafter. Mouse study: Mice were divided into three groups: low (2 mmHg) or high (8 mmHg) IPP or laparotomy. Peritoneal tissue was collected at 0, 4, 8, 24, 48 and 72 h, and 5 and 7 days after surgery. Real-time RT-PCR was performed in humans and mice to measure the levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) mRNA in peritoneal tissues.

RESULTS

Human study: The tPA/PAI-1 mRNA ratio was significantly decreased in the 12 mmHg group at 1 h [P < 0.0001 versus matched initial peritoneal biopsies (MI)]. The tPA/PAI-1 mRNA ratio decreased in both groups at 2 h (P < .0.01 versus MI). Mouse study: The tPA/PAI-1 ratio was decreased at 0 h, and the difference was significant at 4 h in both the laparotomy (P < 0.001 versus controls, 0 h, 5 and 7 days) and high-IPP (P < 0.0001 versus 0, 48 and 72 h, 5 and 7 days) groups. No changes in tPA/PAI-1 ratio were observed in the low-IPP group.

CONCLUSIONS

A low IPP and shorter duration of surgery appear to minimally impact the fibrinolytic system during a CO₂ pneumoperitoneum.

Laparoscopy staging of early ovarian cancer: our experience and review of the literature

We report our experience with laparoscopic staging of apparent early ovarian cancer, and we critically review the current literature on this issue. Potential limits of laparoscopic technique and theoretical concerns of using pneumoperitoneum-based surgery in this setting are addressed.

METHODS

Surgical, pathological, and oncological outcome data of consecutive patients undergoing comprehensive laparoscopic staging for presumed early ovarian cancer at our institution were prospectively collected.

RESULTS

The median operative time was 348 minutes (range, 255-450 minutes). The median estimated blood loss was 250 mL (range, 50-3000 mL). The mean number of pelvic and paraaortic lymph nodes harvested was 24.5 (SD, 6.3) and 9.8 (SD, 7.1), respectively. The disease was upstaged in 6 women (23.1%). No conversion to laparotomy and no intraoperative complication occurred. One patient had a retroperitoneal hematoma recognized in the postoperative period, and this required laparotomy and ligature of the hypogastric arteries to achieve hemostasis. The median follow-up period was 26.7 months (range, 2-83 months). Recurrence-free survival was 96.1%.

CONCLUSIONS

Our results suggest that laparoscopic comprehensive surgical staging is a valuable treatment option for ovarian cancer patients with apparent early disease. Evidence is beginning to accumulate suggesting that minimally invasive surgery is at least equivalent in surgicopathological outcomes and middle-range oncological results to the conventional treatment approach, and early concerns are proving largely unfounded.