Experimental assessment of the risk of tumor recurrence after laparoscopic surgery

Comparison of Surgical and Oncological Outcomes of Laparoscopic and Open Gastrectomy for Pathologically Serosa-Invasive (pT4a) Advanced Gastric Cancer-Retrospective Propensity Score-Matched Analysis

Background: We aimed to clarify the operative feasibility and oncological efficacy of a laparoscopic gastrectomy (LG) for pT4a gastric cancer through comparison with open gastrectomy (OG). Materials and Methods: We compared surgical and oncological outcomes in 178 patients with pT4a gastric cancer who underwent LG or OG between 2002 and 2016; the background was adjusted using propensity score matching. Results: After score matching, 45 patients were included in each group. The LG group had a significantly longer operation time (277 minutes versus 175 minutes, P < .001) and lower estimated blood loss (50 mL versus 280 mL, P < .001). The total number of dissected lymph nodes did not differ between groups (46 versus 38, P = .119); however, the number of dissected suprapancreatic lymph nodes was significantly higher in the LG group (11 versus 7.5, P = .011). Postoperative morbidity rates did not differ between groups. Postoperative hospitalization was significantly shorter in the LG group (7 days versus 13 days, P < .01), whereas overall survival, disease-free survival, and cancer recurrence rates and patterns were similar between groups. Conclusions: LG for pT4a gastric cancer has feasible and acceptable outcomes compared with OG.

Viability of Airborne Tumor Cells during Excision by Ultrasonic Device

Background. Laparoscopic surgery has become more widely used, but peritoneal dissemination and port-site metastasis have been reported to occur in these surgeries. One reason for these problems is the ultrasonically activated scalpel (UAS) used for laparoscopic surgery. This study aimed to investigate the viability of airborne cells released during cancer dissection using a UAS. Methods. Flank tumors measuring about 2 cm were induced in male NOD-Cg-Rag1^tm1MomIL2rg^tm1wjl/SzJ mice by subcutaneous injection of 1 × 10⁶ HepG2 cells. Dissection was performed with UAS (in high or low power modes) and PowerStar bipolar scissors. The mist of released tissue was collected in cell culture medium. The viability of the cellular material was assessed with trypan blue exclusion cell counting, counting after immunofluorescence staining, and flow cytometric analysis. Results. Large quantities of cellular debris were trapped in the tissue dispersed by both devices. In all experiments, there were significantly more viable cells produced by the UAS in high power mode. By using suction at the excision site, the number of viable cancer cells was reduced. Conclusions. This study demonstrates that viable cancer cells can be released into the nearby environment during tumor ablation with a UAS.

Development of a standardized laparoscopic caecum resection model to simulate laparoscopic appendectomy in rats

Background

Laparoscopic appendectomy (LA) has become one of the most common surgical procedures to date. To improve and standardize this technique further, cost-effective and reliable animal models are needed.

Methods

In a pilot study, 30 Wistar rats underwent laparoscopic caecum resection (as rats do not have an appendix vermiformis), to optimize the instrumental and surgical parameters. A subsequent test study was performed in another 30 rats to compare three different techniques for caecum resection and bowel closure.

Results

Bipolar coagulation led to an insufficiency of caecal stump closure in all operated rats (Group 1, n = 10). Endoloop ligation followed by bipolar coagulation and resection (Group 2, n = 10) or resection with a LigaSure™ device (Group 3, n = 10) resulted in sufficient caecal stump closure.

Conclusions

We developed a LA model enabling us to compare three different caecum resection techniques in rats. In conclusion, only endoloop closure followed by bipolar coagulation proved to be a secure and cost-effective surgical approach.

Does carbon dioxide pneumoperitoneum enhance wound metastases following laparoscopic abdominal tumor surgery? A meta-analysis of 20 randomized control studies

The mechanisms involved in the development of wound metastasis following laparoscopic abdominal tumor surgery remain unclear. The aim of this study was to accurately assess whether the duration of carbon dioxide pneumoperitoneum (CDP) during laparoscopic abdominal tumor surgery enhances wound metastases. We conducted a systematic review of PubMed, Cochrane Library, and Embase through December 2013 to identify animal experiments comparing wound recurrence between laparoscopic and gasless laparoscopic procedures or open procedures. The outcome of interest was the number of animals with a wound tumor. Meta-regression was used to assess whether heterogeneity was explained by study level covariates (animal model, study size, CDP pressure, duration, and evaluated time). Twenty randomized control studies involving 1,229 animals were included. Wound recurrence was not significant in the laparoscopic surgery (LP) vs. gasless laparoscopic surgery (GLP) subgroups [odds ratio (OR), 2.23; 95 % confidence interval (CI), 0.90-5.55; P = 0.08) or the LP vs. laparotomy (LA) subgroups (OR, 0.97; 95 % CI, 0.31-3.00; P = 0.08). Overall postoperative wound recurrence results were not significantly different between the study groups and controls (OR, 1.47; 95 % CI, 0.74-2.92; P = 0.28). A meta-regression analysis showed that the outcome was not correlated with the covariates (animal model: P = 0.82; evaluated time: P = 0.30; pressure of CDP: P = 0.12; duration time: P = 0.80). Current evidence suggests that CDP does not enhance wound metastases following laparoscopic abdominal tumor surgery. Additional large sample, well-designed, randomized, controlled trials are needed to further confirm whether CDP duration in laparoscopic abdominal tumor surgery significantly enhances wound recurrence.

Port site metastases after a laparoscopic abdominoperineal resection of rectal cancer: report of a case

This report describes a case of port site metastases that presented 6 months after a laparoscopic abdominoperineal resection of rectal cancer in a 75-year-old man. A surgical excision was performed to improve stoma function despite disease progression with adjuvant concurrent chemoradiation. Although port site metastases are now reported less frequently, this unfortunate consequence of laparoscopic colorectal surgery for cancer can still occur, and laparoscopic colorectal surgeons should exercise all precautions to prevent its occurrence. This report includes a review of literature on port site metastases.

Laparoscopy and Malignancy

BACKGROUND

The advantages of pneumoperitoneum-based surgery are well documented. Laparoscopy is the gold standard of treatment in certain benign conditions such as cholelithiasis and gastroesophageal disease. This success has led to the application of laparoscopy in the management algorithm of malignant conditions. There is currently no universally accepted consensus of the role of pneumoperitoneum-based surgery in the treatment of cancer. This is due to the early reports of port site metastasis, initial lack of randomized controlled trials and the concern of performing oncologically adequate operations. The aim of this section is to review the current literature and attempt to obtain a consensus of the role of laparoscopy in the treatment of cancer.

MATERIALS AND METHODS

A literature search was conducted through Pubmed with key words laparoscopy, pneumoperitoneum, carbon dioxide, malignancy, cancer, and port site metastasis. The obtained results were divided into various sections such as non-randomized reports, randomized reports, animal studies, human studies, etc. A comparison was made between laparoscopic and open resections when possible.

RESULTS

There are several published reports of studies in animal models and in humans relating to pneumoperitoneum-based surgery in the setting of malignancy. There are also a few randomized controlled trials that compared open versus laparoscopic surgery for malignancies of various organ systems. In addition, the early reports of alarmingly high rate of port site metastasis have been scaled down to rates comparable to wound recurrences after open resections.

SUMMARY

Laparoscopy has added another dimension to the management of patients with cancer. Advanced training, superior instrumentation, and a better understanding of the pathophysiology of carbon dioxide pneumoperitoneum has led to the successful application of laparoscopy. The improved results are obtained in centers with high volume of patients and with experience in both fields of oncology and minimally invasive surgery. Laparoscopy is now an integral tool in the management algorithm of malignancies of some organ systems and its role will be further expanded in the future.

Influence of intraperitoneal and systemic application of taurolidine and taurolidine/heparin during laparoscopy on intraperitoneal and subcutaneous tumour growth in rats

BACKGROUND

Recent clinical and experimental studies investigated the problem and possible pathomechanisms of portsite metastases after laparoscopic resection of malignant tumours. A generally accepted approach to prevent these tumour implantations does not exist so far.

METHODS

After subcutaneous and intraperitoneal injection of 10(4) cells of colon adenocarcinoma (DHD/K12/TRb) the influences of either taurolidine or taurolidine/heparin on intraperitoneal and subcutaneous tumour growth were investigated in 105 rats undergoing laparoscopy with carbon dioxide. The animals were then randomised into seven groups. A pneumoperitoneum was established using carbon dioxide for 30 min (8 mmHg). Three incisions were used: median for the insufflation needle, and a right and left approach in the lower abdomen for trocars. To investigate the intraperitoneal (local) influence of either taurolidine and heparin on tumour growth the substances were instilled intraperitoneally. Systemic effects were expected when the substances were applied intravenously (iv). Synergistic influences were tested when both application forms were combined. The number and the weight of tumours as well as the incidence of abdominal wall and port-site metastases were determined four weeks after intervention. Blood was taken to evaluate the influences of taurolidine and heparin on systemic immunologic reactions: seven days before laparoscopy. two hours, two days. seven days, and four weeks after operation, and the peripheral lymphocytes were determined.

RESULTS

Intraperitoneal (ip) tumour weight in rats receiving taurolidine (median 7 mg) and taurolidine/heparin (0 mg) intraperitoneally was significantly reduced when compared to the control group (52 mg) (P = 0.001). There was no difference of subcutaneus tumour growth among the groups (P = 0.4). Trocar recurrences were decreased when taurolidine was applied ip (3115). ipiv (4/15), and ip in combination with heparin (4/15) in comparison to the control group (10/15). Immediately after intervention treated and untreated groups showed a peripheral lymphopenia.

CONCLUSIONS

The intraperitoneal therapy with taurolidine and the combination with heparin inhibits the intraperitoneal tumour growth and trocar recurrences. Neither the intraperitoneal nor the systemic application or the combination of taurolidine and heparin did reduce the subcutaneous tumour growth. The intervention caused a lymphopenia which was compensated on day two.

Impact of pneumoperitoneum on visceral metastasis rate and survival. Results in two ovarian cancer models in rats

OBJECTIVE

To compare the impact of CO2 laparoscopy, gasless laparoscopy, and midline laparotomy on the development of distant metastases and on survival in two ovarian carcinoma models.

DESIGN

A prospective randomised study in rats.

MATERIAL

and methods Two ovarian cancer xenografts were obtained by intraperitoneal injection of IGR-OV1 or NIH-OVCAR-3 cells. Experimental surgical procedures were performed on day 7 (IGR-OVI model) or day 14 (NIH: OVCAR-3 model) after intraperitoneal injection: CO2 laparoscopy (pneumoperitoneum (PNP) with unheated CO2 at a pressure of 8 mmHg for 1 hour); gasless laparoscopy (consisting in abdominal wall expansion by a balloon for 1 hour); midline laparoscopy (consisting in bowel exteriorisation on a mesh for one hour following xyphopubic laparotomy). The control group underwent general anaesthesia alone. The animals were killed by CO2 inhalation as soon as they became moribund.

MAIN OUTCOME MEASURES

Pathological examination was carried out on the liver, lungs and pleura as well as the retroperitoneal nodes. Survival was determined from the time of surgery to the sacrifice of the animal. Statistical analysis used ANOVA, Fisher exact test, Bonferonni method and the log-rank test.

RESULTS

In the IGR-OV1 model, distant metastases were rare, and were not promoted by CO2 laparoscopy. With the NIH: OVCAR-3 model, pleural, pulmonary and para-aortic metastases were not enhanced by CO2 PNP when compared with other approaches. Conversely, midline laparotomy and laparoscopy significantly increased liver involvement when compared with gasless laparoscopy (P = 0.04 and P = 0.008). Survival was comparable no matter what kind of surgery had been performed in the IGR-OV1 model (P = 0.7) or in the NIH: OVCAR-3 model (P = 0.5).

CONCLUSIONS

CO2 laparoscopy had a minor impact on distant and nodal metastases in the two models. Similarly, survival was similar for all surgical groups.