Experimental study of the effect of intra-abdominal pressure during laparoscopy on tumour growth and port site metastasis

Survival Impact of Residual Cancer Cells in Intraoperative Peritoneal Washes following Radical Hysterectomy for Cervical Cancer

Objective: Residual cancer cells (RCCs) contribute to cancer recurrence either because of tumor spillage or undetectable pre-existing micrometastatic tumor clones. We hypothesized that the pathologic evaluation of intraoperative peritoneal washes may reveal RCCs. The aim of this study was to evaluate the survival impact of RCCs identified in intraoperative peritoneal washes and their correlation with clinicopathologic parameters following radical hysterectomy for cervical cancer. Methods: A total of 229 patients with cervical cancer who underwent radical hysterectomy with pelvic and/or paraaortic lymphadenectomy were included. The intraoperative peritoneal washes after surgery were filtered through a strainer and the presence of tumor cells in the residual aspirate was determined. Univariate and multivariate analyses of clinicopathological parameters were performed to identify predictors of recurrence. Results: RCCs in intraoperative peritoneal washes were identified in 19 patients (8.3%). Multivariate analysis revealed that deep stromal invasion (hazard ratio [HR], 13.32; 95% confidence interval [CI], 1.81–98.27; p = 0.0111), lymph node metastasis (HR, 2.00; 95% CI, 1.01–3.99; p = 0.0482), and neoadjuvant chemotherapy (HR, 2.34; 95% CI, 1.89–4.61; p = 0.0139) were associated with tumor recurrence. However, the presence of RCCs was not associated with tumor recurrence (HR, 2.60; 95% CI, 0.74–9.11; p = 0.1352). Multiple logistic regression analysis revealed that RCCs were associated with neoadjuvant chemotherapy (odds ratio [OR], 0.22; 95% CI, 0.05–0.99; p = 0.0488) and large tumor size (OR, 4.16; 95% CI, 0.77–22.48; p = 0.0981). Conclusions: Although the presence of RCCs in intraoperative peritoneal washes do not significantly impact survival outcomes, there was a tendency of inferior survival outcomes in patients with RCCs. RCCs were associated with neoadjuvant chemotherapy and large tumor size.

A comparative population-based analysis of peritoneal carcinomatosis in patients undergoing robotic-assisted and open radical cystectomy

PURPOSE

To compare the population-based incidence of peritoneal carcinomatosis following open (ORC) vs. robotic-assisted radical cystectomy (RARC).

METHODS

Using the Surveillance, Epidemiology and End Results Program (SEER)-Medicare linked data, we identified 1,621 patients who underwent radical cystectomy for bladder cancer during 2009 and 2014; 18.1% (n = 294) and 81.9% (n = 1327) underwent RARC and ORC, respectively. We subsequently evaluated the rates of peritoneal carcinomatosis at 6, 12, and 24 months following surgery. Multivariable proportional hazards regression was performed to determine factors associated with development of peritoneal carcinomatosis.

RESULTS

Patients who underwent RARC vs. ORC were more likely to be male (p = 0.04); however, age at diagnosis, race, comorbidities, education, and marital status (all p > 0.05) did not differ by surgical approaches. Our findings showed that there were no significant differences in the rates of peritoneal carcinomatosis between ORC and RARC at 6, 12, and 24 months. In adjusted analyses, factors associated with peritoneal carcinomatosis were advanced N stage (N0 versus N2/3: HR 0.30, 95% CI 0.16-0.55, p < 0.01), preoperative hydronephrosis (HR 1.70, 95% CI 1.09-2.65, p = 0.04), higher T stage (T1 versus T4: HR 0.34, 95% CI 0.15-0.79, p < 0.01; T2 versus T4: HR 0.39, 95% CI 0.20-0.76, p < 0.01), and use of neoadjuvant chemotherapy (HR 1.78, 95% CI 1.11-2.84, p < 0.01). However, RARC was not associated with peritoneal carcinomatosis (HR 1.36, 95% CI 0.78-2.35).

CONCLUSION

In this population-based analysis, we found no difference in peritoneal carcinomatosis between robotic or open approaches to radical cystectomy. These data should be reassuring to those utilizing robotic cystectomy.

The effect of CO2 pressure and flow variation on carbon particles spread during pneumoperitoneum: an experimental study

BACKGROUND

A correlation between atypical recurrences and minimally-invasive surgery has been suggested in case of urothelial cancer; however, very few data are available on the role of pneumo peritoneum in terms of gas flow and intra-abdominal pressure. The objective of the study is to analyze the impact of CO2 pneumoperitoneum variation on an inert material as surrogate of neoplastic cells.

MATERIAL AND METHODS

We designed an experimental model mimicking pneumoperitoneum in three settings: sealed flow (no leakage), pulsatile flow (alternating efflux and influx) and continuous flow (AirSeal® insufflator). Each experiment was characterized by a pre-determined gas flow and pressure, trocar distance and position from the particles. Hounsfield density (HD) variation in the areas of interest was measured as index of graphite powder dispersion. A Linear regression model was employed to measure the correlation between modifiable variables and HD.

RESULTS

HD was lower in the pulsatile compared to both the sealed and continuous flows (p < 0.03). On multivariate analysis for sealed setting, flow and total gas liters delivered (i.e. gas leakage) were inversely and independently related to HD (all p <0.03). In pulsatile setting, trocar position, trocar distance and gas flow independently predicted HD (all p <0.03). In continuous setting, gas pressure was directly and independently related to HD (p = 0.004) due to decreased pneumoperitoneum stability and increased CO2 liters delivered. In case of in-flow trocar positioned laterally to the particles, low flow (1 L/min) or low pressure (8 mmHg), HD values recorded in the three settings were all overlapping (all p > 0.05).

CONCLUSIONS

Flow and pressure setting, in-flow trocar distance and contiguity from the tumor, and pneumoperitoneum stability may be all crucial component in minimally invasive surgery. In vivo, these variables should be considered as potential risk factors for tumor cells spread within the abdominal cavity.

Oncologic Outcomes of Intracorporeal vs Extracorporeal Urinary Diversion After Robot-Assisted Radical Cystectomy: A Multi-Institutional Korean Study

Background: We aimed to compare the oncologic outcomes of intracorporeal urinary diversion (ICUD) and extracorporeal urinary diversion (ECUD) following robot-assisted radical cystectomy (RARC) in patients diagnosed with bladder cancer. Materials and Methods: Medical records of 730 patients who underwent RARC between April 2007 and May 2019 in 11 tertiary referral centers were retrospectively reviewed. We assessed recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) in the two groups using the Kaplan-Meier method. Cox regression models were used to identify factors associated with RFS, CSS, and OS. Results: Among 591 patients, neobladder diversion was performed more frequently in the ICUD group (70.8% vs 52.5%, p = 0.001). The median follow-up duration was shorter in the ICUD group than in the ECUD group (16 vs 26 months, p < 0.001). The rates of overall recurrence (36.5% vs 25.5%, p = 0.013) and pelvic recurrence (12.1% vs 5.9%, p = 0.031) were higher in the ECUD group. However, no differences in 5-year RFS (43.2% vs 58.4%, p = 0.516), CSS (79.3% vs 89.7%, p = 0.392), and OS (74.3% vs 81.4%, p = 0.411) were noted between the two groups. Multivariable analysis revealed that when compared to ICUD, ECUD was not associated with RFS (hazard ratio [HR], 0.982; p = 0.920), CSS (HR, 0.568; p = 0.126), and OS (HR, 0.642; p = 0.124). Conclusion: Although there was a difference in recurrence rate between the two groups, multivariable analysis indicated that the diversion technique after RARC did not affect the oncologic outcomes. Large prospective studies with long-term follow-up are warranted to verify the oncologic outcomes of ICUD and ECUD following RARC.

Atypical oncologic failure after laparoscopic and robot-assisted radical cystectomy at a single institution

BACKGROUND

The incidence of atypical oncologic failure in patients with bladder cancer, including peritoneal carcinomatosis, and recurrences at the port site and soft tissue after laparoscopic and robot-assisted radical cystectomy are not well characterized.

METHODS

We retrospectively reviewed the records of 52, 51, and 12 patients who underwent open, laparoscopic, and robot-assisted radical cystectomy, respectively, for bladder cancer from 2007 to 2018 at our institution. We identified techniques associated with atypical oncologic failure.

RESULTS

The median follow-up period was 29 months. Among the 115 patients, 29 (25%) experienced oncological recurrences, and 7 (6%), 12 (10%), and 23 (20%) had atypical, local, and distant recurrences, respectively. The laparoscopic and robot-assisted radical cystectomy groups had significantly higher incidences of total atypical oncologic failure than the open radical cystectomy group (p = 0.013), including six, one, and two patients with peritoneal carcinomatosis, port site carcinomatosis, and soft tissue involvement, respectively. All 7 patients with atypical oncologic failure died of cancer; the median time from surgery to death was 9.3 months. All these patients were cT ≧ 3 and had grade 3 disease. In three patients (43%), the pathological tissue contained variants other than urothelial carcinoma. Five (71%) were among the initial twenty patients. Four patients (57%) had histories of intraoperative urine spillage or bladder perforation during transurethral resection.

CONCLUSIONS

Patients with cT ≧ 3 stage, with pathological variants other than urothelial carcinoma, and those undergoing procedures that lead to extravesical dissemination should avoid laparoscopic radical cystectomy when the procedures are first introduced.

Port-site metastasis and atypical recurrences after robotic-assisted radical cystectomy (RARC): an updated comprehensive and systematic review of current evidences

The objective of this systematic review is to evaluate the current evidence regarding atypical metastases in patients undergoing robotic-assisted radical cystectomy (RARC). A review of the current literature was conducted through the Medline and NCBI PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar databases in October 2019. From the literature search using the cited keys and after a careful evaluation of the full texts, we included 31 articles in the study. Fourteen studies (45.2%) reported at least an atypical recurrence during the follow-up period with a rate between 4 and 40% of all the recurrences. Overall, 105 (1.63%) of the 6720 patients who have been evaluated in the included studies developed an atypical recurrence. Sixty-three (60%) of these atypical metastases were peritoneal carcinomatosis, 16 (15.2%) extrapelvic lymph nodes metastases, 11 (10.5%) port-site metastases, 10 (9.5%) retroperitoneal nodal metastases, while 5 (3.8%) patients developed more than one type of atypical recurrence. In literature, there is a low but not negligible incidence of atypical recurrences after RARC. However, publication bias and retrospective design of most studies could influence the evidences. Further prospective randomized studies are needed to clarify the real risk of patients undergoing RARC to develop atypical metastases.

Accurate Quantification of Residual Cancer Cells in Pelvic Washing Reveals Association with Cancer Recurrence Following Robot-Assisted Radical Cystectomy

PURPOSE

Bladder cancer recurrence following cystectomy remains a significant cause of bladder cancer specific mortality. Residual cancer cells contribute to cancer recurrence due to tumor spillage or undetectable preexisting micrometastatic tumor clones. We detected and quantified residual cancer cells in pelvic washing using ultradeep targeted sequencing. We compared the levels of residual cancer cells with clinical variables and cancer recurrence.

MATERIALS AND METHODS

The primary tumor specimen was available in 17 patients who underwent robot-assisted radical cystectomy. All tumors had negative surgical margins. Pelvic washes and blood were collected intraoperatively before and after robot-assisted radical cystectomy, after pelvic lymph node dissection and in the suction fluid collected during the procedure. Two-step sequencing, including whole exome sequencing followed by ultradeep targeted sequencing (× greater than 50,000), was done to quantify residual cancer cells in each sample. Eight patients were excluded from study due to sample quality issues. The final analysis cohort comprised 9 patients. The residual cancer cell level was quantified for each sample as the relative cancer cell fraction and compared between time points. The peak relative cancer cell fraction of each patient was correlated with clinical and pathological variables.

RESULTS

Residual cancer cells were detected in approximately half of the pelvic washing specimens during or after but not before robot-assisted radical cystectomy. Higher residual cancer cell levels were associated with aggressive variant histology and cancer recurrence. Verifying the feasibility of using residual cancer cells as a novel biomarker for recurrence requires larger cohorts.

CONCLUSIONS

Detection of residual cancer cells in intraoperative peritoneal washes of patients with bladder cancer who undergo radical cystectomy may represent a robust biomarker of tumor aggressiveness and metastatic potential.

Evidence of Atypical Recurrences After Robot-Assisted Radical Cystectomy: A Comprehensive Review of the Literature

Robot-assisted radical cystectomy (RARC) has seen remarkable growth in the last decade. Despite a low level of evidence, numerous publications reporting on outcomes after RARC are now available. While definitive data on the long-term oncologic safety and efficacy of this technique are still lacking, similar oncological and functional outcomes compared to open radical cystectomy (ORC) have been reported. Several studies have also reported on atypical recurrences after RARC, including peritoneal carcinomatosis, extra-pelvic lymph node metastasis and port-site metastasis. While distant metastases overall do not appear to be affected by technique, it is possible that RARC may be associated with an increased risk of some atypical recurrences and this should be prospectively studied in RARC. However, atypical recurrences are rare events and are infrequent in their description. To date, there is no convincing evidence that, in the hands of equally experienced surgeons who treat bladder cancer routinely, a skillfully performed RARC is less oncologically efficacious than a skillfully performed ORC.

Early Oncologic Failure after Robot-Assisted Radical Cystectomy: Results from the International Robotic Cystectomy Consortium

PURPOSE

We sought to investigate the prevalence and variables associated with early oncologic failure.

MATERIALS AND METHODS

We retrospectively reviewed the IRCC (International Radical Cystectomy Consortium) database of patients who underwent robot-assisted radical cystectomy since 2003. The final cohort comprised a total of 1,894 patients from 23 institutions in 11 countries. Early oncologic failure was defined as any disease relapse within 3 months of robot-assisted radical cystectomy. All institutions were surveyed for the pneumoperitoneum pressure used, breach of oncologic surgical principles, and techniques of specimen and lymph node removal. A multivariate model was fit to evaluate predictors of early oncologic failure. The Kaplan-Meier method was applied to depict disease specific and overall survival, and Cox proportional regression analysis was used to evaluate predictors of disease specific and overall survival.

RESULTS

A total of 305 patients (22%) experienced disease relapse, which was distant in 220 (16%), local recurrence in 154 (11%), peritoneal carcinomatosis in 17 (1%) and port site recurrence in 5 (0.4%). Early oncologic failure developed in 71 patients (5%) at a total of 10 institutions. The incidence of early oncologic failure decreased from 10% in 2006 to 6% in 2015. On multivariate analysis the presence of any complication (OR 2.87, 95% CI 1.38-5.96, p = 0.004), pT3 or greater disease (OR 3.73, 95% CI 2.00-6.97, p <0.001) and nodal involvement (OR 2.14, 95% CI 1.21-3.80, p = 0.008) was a significant predictor of early oncologic failure. Patients with early oncologic failure demonstrated worse disease specific and overall survival (23% and 13%, respectively) at 1 and 3 years compared to patients who experienced later or no recurrences (log rank p <0.001).

CONCLUSIONS

The incidence of early oncologic failure following robot-assisted radical cystectomy has decreased with time. Disease related rather than technical related factors have a major role in early oncologic failure after robot-assisted radical cystectomy.

Camera-port site metastasis of a renal-cell carcinoma after robot-assisted partial nephrectomy

BACKGROUND AND PURPOSE

Port-site metastasis (PSM) is a rare complication of laparoscopic intervention in urologic malignancies. Of the greater than 50 reported cases of PSM in the urologic oncology literature, only 9 have occurred after surgery for renal-cell carcinoma (RCC). We report a 10th instance of RCC metastasis-in this case to the camera-port site after robot-assisted partial nephrectomy (RAPN). To our knowledge, this case is the first reported PSM of RCC after RAPN.

PATIENT AND METHODS

A 68-year-old man underwent an uncomplicated right RAPN for a 4-cm right renal mass (stage T1aN0M0). Five months later, he was found to have metastatic disease with an isolated peritoneal recurrence at the camera-port site. Biopsy of the lesion confirmed RCC, and the lesion was surgically resected. A comprehensive MEDLINE search for all published studies of port-site recurrences after laparoscopic renal surgery for RCC was performed.

RESULTS

Nine cases of PSM after successful laparoscopic radical or partial nephrectomy for locally confined RCC have been reported. Proposed etiologic factors for port-site recurrence include biologic aggressiveness of the tumor, patient immunosuppression, local wound factors, and technique-related factors. We report an unusual case of PSM to a camera port that was not used for specimen manipulation or extraction.

CONCLUSION

PSM after laparoscopic renal surgery for RCC is a rare occurrence. Our case, in which PSM occurred without specimen bag rupture or extraction through the port in question, highlights the importance of local and systemic factors in contributing to PSM occurrence. We also demonstrate that when PSM is the only site of disease recurrence, it can be successfully managed with minimally invasive surgical resection.

Laparoscopic versus open left lateral segmentectomy

BACKGROUND

Laparoscopic liver surgery is becoming increasingly common. This cohort study was designed to directly compare perioperative outcomes of the left lateral segmentectomy via laparoscopic and open approach.

METHODS

Between 2002 and 2006 43 left lateral segmentectomies were performed at King's College Hospital. Those excluded from analysis included previous liver resections, polycystic liver disease, liver cirrhosis and synchronous operations. Of 20 patients analysed, laparoscopic (n = 10) were compared with open left lateral segmentectomy (n = 10). Both groups had similar patient characteristics.

RESULTS

Morbidity rates were similar with no wound or chest infection in either group. The conversion rate was 10% (1/10). There was no difference in operating time between the groups (median time 220 minutes versus 179 minutes, p = 0.315). Surgical margins for all lesions were clear. Less postoperative opiate analgesics were required in the laparoscopic group (median 2 days versus 5 days, p = 0.005). The median postoperative in-hospital stay was less in the laparoscopic group (6 days vs 9 days, p = 0.005). There was no mortality.

CONCLUSION

Laparoscopic left lateral segmentectomy is safe and feasible. Laparoscopic patients may benefit from requiring less postoperative opiate analgesia and a shorter post-operative in-hospital stay.

Application of a solid tumor model to evaluate tumor recurrence after an open or laparoscopic rectal resection in rats

PURPOSE

We used a solid tumor model to evaluate the influence of laparotomy versus laparoscopy on tumor growth after curative resection for rectal cancer in rats.

METHODS

Colon tumor cells (DHD/K12/TRb) were administered intraperitoneally in 15 rats, which were used as solid tumor donors. Twenty-one days later, a 20-mg piece was then implanted in the rectal submucosa of the study rats (n=45). Animals were randomized into 3 groups for rectal resection either open or laparoscopic using either carbon dioxide (CO2) or helium for pneumoperitoneum. Autopsy took place 21 days after resection and tumor recurrence was evaluated.

RESULTS

Port-site metastasis was observed after laparoscopy with CO2 (1 animal) and helium (1), whereas intraperitoneal tumor growth was detected in 2 and 3 animals of these groups. No tumor recurrence was observed after open surgery.

CONCLUSIONS

Our solid tumor model is a novel neoplastic model that might simulate the clinical situation of an upper rectal carcinoma. It might be helpful to develop new protocols in studying solid tumor biology and different surgical procedures for cancer to address problematic issues in oncologic research.

Effects of simulated carbon dioxide and helium peumoperitoneum on proliferation and apoptosis of gastric cancer cells

AIM

To investigate the effects of carbon dioxide (CO(2)) and helium insufflation administered at different pressures on the growth and apoptosis of cultured human gastric cancer cells.

METHODS

The gastric cancer cells MKN-45 were exposed to a CO(2) and helium environment maintained at different pressures (0, 5, 10 and 15 mmHg). The cells were exposed to simulated pneumoperitoneum environment for 4 h, and pH of the culture media was measured after it was moved to normal conditions for 0, 2, 4, 6 and 8 h. Proliferation viability of MKN-45 was examined by 3-[4,5Dimethylthiazol-2-yl],5-diphenyltetrazolium bromide or triazolyl blue (MTT) assay after it was moved to normal conditions. Apoptotic ratio was measured by Annexin V-FITC/PI double labelled staining.

RESULTS

The pH of media was acid and recovered to normal after 4 h in the CO(2) group while it was basic in the helium group. There was no difference between CO(2) groups (under 10 mmHg ) and control group (P > 0.05) in the proliferative viability of the cells. The cultured cells exposed to 15 mmHg CO(2) environment grew more slowly than control group from 4 to 7 d (P < 0.01 ) while there was no difference from 1 to 3 d (P > 0.05). The proliferative viability in helium group was not obviously different from the control group (P > 0.05). The apoptotic ratio of the cultured cells was markedly higher than that of the control group (P < 0.01) at 10 and 15 mmHg CO(2) insufflation pressure. In helium group, the apoptotic ratio was not obviously different from the control group (P > 0.05).

CONCLUSION

There is no obvious effect in the proliferation and apoptosis of MKN-45 cells under 10 mmHg CO(2) insufflation pressure and helium in any pressure. Fifteen mmHg CO(2) insufflation pressure can inhibit the proliferation of the cells and improve apoptosis.

Effect of types of resection and manipulation on trocar site contamination after laparoscopic colectomy: An experimental study in rats with intraluminal radiotracer application

BACKGROUND

The etiology and incidence of port-site metastases after laparoscopic surgery for colorectal cancer remain unknown. The purpose of this experimental study was to detect and quantify the amount of contamination at the port-site by means of a method utilizing radiolabelled colloid particles following extra- or intracorporeal laporoscopic resection of cecum.

METHODS

Prior to experimental surgery, we obtained a high concentration of luminal colonic radiotracer activity by per anum application of sulphur colloid molecules labelled with Tc-99m pertechnetate. In three main groups of rats, we either resected a portion of cecum extracorporeally or intracorporeally, or did no resection. Each main group was further divided into two subgroups, in which the manipulations were either autraumatic or traumatic. We excised trocar sites as 2 cm doughnuts after completion of the surgical procedure. We used gamma camera imaging to quantify the amount of radioactive contamination at trocar sites. The background corrected trocar site activity for each rat was calculated. Activities exceeding the maximum background activity were accepted as trocar site contamination.

RESULTS

We detected an overall incidence of contamination in 44% of rats. This rate were 71% and 17% in traumatic and atraumatic subgroups. The resection itself increased the rate and intensity of contamination, as well (p = 0.04). The most intensive contamination was detected in the intracorporeal resection with traumatic manipulation subgroup (p = 0.0007).

CONCLUSIONS

Both the presence of resection and manipulative trauma seemed to be increasing the rate and intensity of the radioactive activity at the trocar site. When traumatic manipulatiun was exercised, the contamination was so intense that the type of resection did not differ. We concluded that our scintigraphic method would be useful in the intraoperative detection of port site contamination by the tumor cells, and that surgeons would take some preventive measures to prevent future port-site metastases.

Is carbon dioxide insufflation safe for laparoscopic surgery? A model to assess the effects of carbon dioxide on transitional-cell carcinoma growth, apoptosis, and necrosis

PURPOSE

To study the effects of carbon dioxide insufflation pressure and concentration on the adhesion, growth, apoptosis, and necrosis of transitional-cell carcinoma (TCC).

MATERIALS AND METHODS

Adhesion and growth of the AY-27 rat TCC cell line was measured after CO2 insufflation in vitro at different pressures ranging from 0 to 15 mm Hg and after incubation in CO2-air mixtures at 5%, 10%, and 15% CO2 by volume.

RESULTS

Tumor adhesion decreased significantly after CO2 insufflation. For all insufflation pressures, there was an increase in cell growth, apoptosis, and necrosis for the first 24 hours followed by a steady decline. High concentrations of CO2 (>5%) inhibited cell growth for only the first 48 hours. The effects of CO2 pneumoperitoneum on tumor-cell adhesion, growth inhibition, apoptosis, and necrosis were more prominent at high CO2 pressure (> or =15 mm Hg) and concentration (>5% CO2). However, insufflation pressure had a greater inhibitory effect on tumor growth than did CO2 concentration. High insufflation pressures and CO2 concentrations significantly decreased extracellular pH.

CONCLUSION

The short-term effect of CO2 on TCC growth and apoptosis is complex. Overall, CO2 has a toxic effect on TCC and inhibits cell adhesion and growth. High CO2 concentrations (>5%) and high insufflation pressures (> or =15 mm Hg) are most effective in decreasing tumor-cell adhesion and growth.

Laparoscopy and collagen metabolism

The collagens represent a vital component within the wound healing process and physiological scar formation. Therefore, analysing the influence of new operative procedures on collagen metabolism is of great surgical interest. As the endoscopic technique has, nowadays, become routinely applied for diverse abdominal diseases worldwide, we present a review of literature facing its impact on collagen biology.

Port site metastases after robot-assisted laparoscopic radical cystectomy

Laparoscopy has become a well-established alternative to open surgery for the management of many urologic tumors. Metastases at one of the port sites is not a common complication, though there are some reports of port site metastases after laparoscopic management for renal tumors and pelvicaliceal tumors, as well as after laparoscopic lymphadenectomy. Herein, we report a case of port site metastases after robot-assisted laparoscopic radical cystectomy for muscle-invasive bladder cancer. To the best of our knowledge this is the first case of such pathology to be reported. Although rare, the laparoscopic surgeon should be aware of such complications when dealing with malignant masses.

Effects of pneumoperitoneal gases and pressures on transitional cell carcinoma adhesion, growth, apoptosis and necrosis: an in vitro study

PURPOSE

We studied the effects of insufflation gas and pressure on the adhesion, growth, apoptosis and necrosis of transitional cell carcinoma (TCC) in an in vitro model.

MATERIALS AND METHODS

Tumor adhesion and cell growth of AY-27 rat TCC was measured after 3-hour incubation with CO2, N2 and He insufflation at different pressures (0, 10 and 15 mm Hg) in vitro. The effects of these gases on the rate of tumor cell apoptosis and necrosis were compared.

RESULTS

In vitro the tumor adhesion rate was lowest with CO2 and highest with N2. Higher gas pressures resulted in decreased adhesion rates for CO2 and He but increased adhesion rates for N2. N2 enhanced tumor cell proliferation at all pressures studied. He and CO2 resulted in an initial increase in cell proliferation in the first 24 hours, followed by a decrease in tumor growth. Extracellular medium turned acidic in CO2 (pH 6.27 to 6.39) but basic in N2 and He (pH 8.39 to 8.84). At all insufflation pressures studied apoptosis and necrosis rates were increased in the first 24 hours, followed by a decrease for CO2 and N2. He resulted in increasing apoptosis and necrosis throughout the study period.

CONCLUSIONS

The type of gas and insufflation pressure affects cell adhesion and tumor growth. There was a significant increase in tumor adhesion and proliferation with N2 insufflation compared with CO2 and He at 0 to 15 mm Hg pressures. CO2 demonstrated the greatest decrease in TCC adhesion and proliferation at 15 mm Hg pressure. Apoptosis and necrosis were highest for He compared with the other gases.

Laparoscopic environmental changes during surgery enhance the invasive potential of tumours

OBJECTIVE

The use of laparoscopic techniques in resection of malignant tumours has been proposed to offer potential benefit to the patient in the form of earlier recovery and less immune paresis; however, reported tumour seeding, both peritoneal and at port site, has put this approach into question. The biological effects of the introduction of carbon dioxide or helium to form a pneumoperitoneum on tumour invasion and dissemination are unknown.

METHODS

A human colonic adenocarcinoma cell line (SW1222) was exposed to in vitro laparoscopic environment of either carbon dioxide or helium for 4 h, mimicking the duration of a laparoscopic colorectal resection. Alteration in production of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase-type plasminogen activator (uPA) due to exposure to a laparoscopic environment was determined by zymography and correlated to invasive capacity by a standard Matrigel-based invasion assay. Incorporation of specific gelatinase inhibitors or antibodies directed at the uPA receptor was utilized to determine the relative importance of proteases.

RESULTS

Exposure to the laparoscopic environment significantly enhanced production of the proteases MMP-2, MMP-9 and uPA. A concomitant enhancement of invasive capacity was also observed, being blocked by specific protease inhibitors. Changes in both protease production and aggression were observable for at least 24 h following the removal of the operative environment, indicating the possible long-term effects of the initial insult.

CONCLUSION

Exposure to the laparoscopic environment enhances the invasive capacity of colonic adenocarcinomas via a well-defined protease-determined pathway. It therefore appears likely that tumour cells released into the operative field can be made increasingly aggressive by a laparoscopic operative environment and can thus contribute to disease dissemination.

Impact of taurolidin and octreotide on liver metastasis and lipid peroxidation after laparoscopy in chemical induced ductal pancreatic cancer

BACKGROUND

There is controversial discussion whether metastasis initiated by laparoscopy with carbon dioxide might be prevented by instillation of taurolidin or radical scavengers like the somatostatin analogue Octreotide. Therefore we evaluated the effects of laparoscopic lavage with taurolidin and Octreotide on liver metastasis after staging laparoscopy in ductal pancreatic cancer.

METHODS

In 60 Syrian hamsters pancreatic adenocarcinoma was induced by weekly subcutanous injection of 10 mg N-nitrosobis-2-oxopropylamin/kg body weight for 10 weeks. In the 16th week laparoscopic staging biopsy by use of carbon dioxide was performed. Finally animals underwent abdominal irrigation with saline (gr.1, n = 20), taurolidin (0.5%) (gr.2, n = 20) or Octreotide (gr.3, n = 20). In week 25 animals were sacrificed, pancreas and liver were analysed.

RESULTS

Size of pancreatic carcinomas was decreased in the taurolidin gr. compared to the other two groups. Furthermore the number of liver metastasis per animal was reduced after lavage with taurolidin (2 +/- 2) and Octreotide (2.5 +/- 2) compared to saline irrigation (4 +/- 4) (p < 0.05). Additionally the incidence of port site metastases was significantly reduced in the taurolidin group. Activity of antioxidative enzyme superoxide dismutase (SOD) was increased while concentration of products of lipidperoxidation was decreased in non-metastatic liver after taurolidin irrigation compared to saline or Octreotide irrigation.

CONCLUSIONS

Taurolidin irrigation during laparoscopy might be a new concept to reduce the number of liver metastasis and port site metastases in pancreatic cancer.

Extracellular pressure stimulates colon cancer cell proliferation via a mechanism requiring PKC and tyrosine kinase signals

Pressure in colonic tumours may increase during constipation, obstruction or peri-operatively. Pressure enhances colonocyte adhesion by a c-Src- and actin-cytoskeleton-dependent PKC-independent pathway. We hypothesized that pressure activates mitogenic signals.

METHODS

Malignant colonocytes on a collagen I matrix were subjected to 15 mmHg pressure. ERK, p38, c-Src and Akt phosphorylation and PKCalpha redistribution were assessed by western blot after 30 min and PKC activation by ELISA. Cells were counted after 24 h and after inhibition of each signal, tyrosine phosphorylation or actin depolymerization.

RESULTS

Pressure time-dependently increased SW620 and HCT-116 cell counts on collagen or fibronectin (P < 0.01). Pressure increased the SW620 S-phase fraction from 28 +/- 1 to 47 +/- 1% (P = 0.0002). Pressure activated p38, ERK, and c-Src (P < 0.05 each) but not Akt/PKB. Pressure decreased cytosolic PKC activity, and translocated PKCalpha to a membrane fraction. Blockade of p38, ERK, c-Src or PI-3-K or actin depolymerization did not inhibit pressure-stimulated proliferation. However, global tyrosine kinase blockade (genistein) and PKC blockade (calphostin C) negated pressure-induced proliferation.

CONCLUSIONS

Extracellular pressure stimulates cell proliferation and activates several signals. However, the mitogenic effect of pressure requires only tyrosine kinase and PKCalpha activation. Pressure may modulate colon cancer growth and implantation by two distinct pathways, one stimulating proliferation and the other promoting adhesion.

Port site metastases

BACKGROUND

Concerns about port site metastases have limited the application of minimally invasive surgery for intra-abdominal malignancies. The purpose of this review article was to summarize the current literature regarding port site metastases.

METHODS

A Medline search identified >100 articles in English published during the last 15 years regarding the history, incidence, etiology, and prevention of port site metastases. These articles were reviewed and are summarized.

RESULTS

The incidence of port site metastases, initially thought to be as high as 21%, is now thought to be closer to the incidence of wound metastases after open surgery. Multiple etiologic factors have been studied including direct wound contamination, surgical technique, effects of carbon dioxide pneumoperitoneum, and changes in host immune response. Various preventive measures have been proposed.

CONCLUSIONS

Port site metastases are a well-documented and devastating complication after laparoscopic resection of intra-abdominal malignancies. Although the etiology is not yet understood, a number of factors are contributory. All efforts should be made to prevent port site metastases.

Laparoscopic colon resection for colon cancer

INTRODUCTION

Laparoscopic colon resection for cancer is as yet an unproven operation. This review article summarizes current data on the topic.

METHODS

A Medline review identified articles published since 1990 summarizing patients with potentially curable colon cancer who underwent a laparoscopic-assisted colon resection. Only articles that were randomized or had a control group with historical or matched open cases were used.

RESULTS

Very few prospective randomized controls exist. Several clinical trials are under way with one completed. Data thus far support some patient benefits with a laparoscopic approach. No differences in morbidity, oncologic data, or survival appear to exist.

CONCLUSIONS

The results of ongoing clinical trials are still needed to further evaluate the role of laparoscopic assisted colon resection in patients with potentially curable colon cancer.

Effect of laparotomy and CO(2) pneumoperitoneum on tumor growth of human colon carcinoma and expression pattern of tumor-associated proteins in the SCID mouse

BACKGROUND AND AIMS

The impact of laparoscopy on tumor progression is still unclear. This study investigated the effect of CO(2) pneumoperitoneum on the intra-abdominal growth of human colon carcinoma independently of the effect of the immune system.

METHODS

SCID mice underwent either median laparotomy or laparoscopy. Human colon carcinoma cells were implanted into the upper abdomen. The control group was not operated on following cell injection. Tumor growth and the protein expression pattern of proliferation marker Ki67, cell-cell adhesion molecules E-cadherin, alpha- and beta-catenin, and cell-extracellular matrix adhesion molecules CD44 v5 and v6 in tumor tissue were analyzed on postoperative day 14.

RESULTS

Total tumor volume in the laparoscopy group significantly exceeded that in the laparotomy group. Immunohistochemistry revealed reduced expression of alpha-catenin and elevated expression on beta-catenin and CD44 v5 in the tumor tissue of the laparoscopy group.

CONCLUSION

The expression pattern of proteins associated with tumor progression and the increase in tumor growth suggest an increased risk of laparoscopy at least for the growth of advanced human colon carcinoma.

Effects of taurolidine and octreotide on tumor growth and lipid peroxidation after staging-laparoscopy in ductal pancreatic cancer

Irrigation with taurolidine after laparoscopy decreases tumor growth in colon carcinoma. In pancreatic cancer subcutaneous therapy with octreotide decreases oxidative stress and carcinogenesis as well. However, it is still unclear, whether irrigation with taurolidine or octreotide after laparoscopic pancreatic biopsy reduces tumor growth in pancreatic cancer as well. In 60 Syrian hamsters ductal pancreatic adenocarcinoma was induced by weekly injection of 10mg/kg body weight N-nitrosobis-2-oxopropylamine s.c. for 10 weeks. In week 16 laparoscopic pancreatic biopsy by use of carbon dioxide was performed (gr. 1, n = 20) with subsequent laparoscopic irrigation with taurolidine (gr. 2, n = 20) or octreotide (gr. 3, n = 20). In week 25 hamsters were sacrificed. Our results show that macroscopic visible primary tumors were found in only one animal of the taurolidine group (5.9%), compared to 42.1% in the saline and 62.5% in the octreotide group (P<0.05). Carcinomas were smaller after saline (6+/-23 mm(2)) than after octreotide irrigation (70+/-120 mm(2), P<0.05). In conclusion this study showed that laparoscopic irrigation with taurolidine after pancreatic biopsy inhibited tumor growth in ductal pancreatic adenocarcinoma.

Laparoscopic port-site metastases: etiology and prevention

OBJECTIVE

The purpose of this article is to summarize current hypotheses for the possible sources of laparoscopic port-site metastasis, to review the results of experimental models that support such hypotheses, and to discuss the potential options for preventing these metastases.

METHODS

We performed a Medline search to identify in vitro and in vivo studies and clinical trials that analyzed port-site metastases associated with laparoscopic surgery. We report the incidence of port-site metastases and causative factors associated with this condition.

RESULTS

The estimated incidence of port-site metastases in all patients undergoing laparoscopic surgery for malignant disease is approximately 1-2%. Multiple factors are associated with this complication. Among the most common proposed etiologies are the wound implantations caused by the surgical technique and instrumentation; the leakage of insufflation gas through the ports, known as the "chimney effect"; and the impact of pneumoperitoneum on local immune reactions. Several preventive measures, have been suggested, including careful patient selection, lavage of the peritoneal cavity as well as of the port wounds with cytotoxic agents, and modifications of surgical technique.

CONCLUSIONS

Only through the results of well-conducted large multi-institutional prospective randomized trials will we learn not only the true incidence of port-site metastases, but also the potential factors that lead to the occurrence of this complication.

Port site metastases in urological laparoscopic surgery

PURPOSE

Laparoscopic surgery is rapidly gaining widespread acceptance among urologists, including extensive application in malignant conditions. However, untoward occurrences of port site metastases have not eluded to urological applications. This up-to-date review on port site metastases in urology delineates possible contributing factors and describes techniques to prevent it.

MATERIALS AND METHODS

We comprehensively reviewed published experimental and clinical studies with special emphasis on the incidence, pathophysiology and prevention of port site metastases.

RESULTS

Nine cases of port site metastases after urological laparoscopy have been described in clinical and experimental studies. Etiological factors include natural malignant disease behavior, host immune status, local wound factors, laparoscopy related factors such as aerosolization of tumor cells (the use of gas, type of gas, insufflation and desufflation, and pneumoperitoneum) and sufficient technical experience of the surgeons and operating team (adequate laparoscopic equipment, skill, minimal handling of the tumor, surgical manipulation and wound contamination during instruments change, organ morcellation and specimen removal).

CONCLUSIONS

Port site metastases is a multifactorial phenomenon with an as yet undetermined incidence. The problem is influenced to some extent by surgeon and operating team experience and, therefore, it could be partially prevented. The suggested preventive steps are avoiding laparoscopic surgery when there are ascites, trocar fixation to prevent dislodgment, avoiding gas leakage along and around the trocar, sufficient technical readiness of the operating team (adequate laparoscopic equipment and technique, minimal handling and avoiding tumor boundary violation of the tumor), using a bag for specimen removal, placing drainage when needed before desufflation, povidone-iodine irrigation of instruments, trocars and port site wounds, and suturing 10 mm. and larger trocar wounds.

[Prevention of port-site metastasis after laparoscopy]

Port-site metastasis is a major complication of surgical laparoscopy for gynaecologic oncology. Aetiology of port-site metastases is multifactorial. Surgical conditions and laparoscopic environment were determinant. Several means of prevention were evaluated to prevent occurrence of port-site metastases. Aim of this review is to report optimal surgical conditions, laparoscopic environment and means of prevention to decrease risk of port-site metastases.

Effect of carbon dioxide on human ovarian carcinoma cell growth

OBJECTIVE

Laparoscopy may be associated with increased risk of ovarian carcinoma wound metastases. This study was designed to determine whether carbon dioxide exposure increases the growth of human ovarian cancer cells in vitro.

STUDY DESIGN

Immortalized ovarian epithelial carcinoma cell (SKOV-3 cell line) cultures were exposed to carbon dioxide, nitrous oxide, or culture media with decreased pH for up to 3 hours. Cell growth was determined with the use of a spectrophotometric assay, and the results were compared with control cells by paired t tests and linear regressions analysis.

RESULTS

Carbon dioxide exposure increased SKOV-3 cell growth by 52% after 4 days in culture. The increased cell growth had a linear relationship to the length of carbon dioxide exposure. Cells that were exposed to either nitrous oxide or media with pH 6.3 showed a trend toward decreased growth.

CONCLUSION

Carbon dioxide exposure increases the in vitro growth of human ovarian carcinoma cells by an effect that is independent of the carbon dioxide-related decrease in the culture media pH.

Morphology of the murine peritoneum after pneumoperitoneum vs laparotomy

BACKGROUND

Although there have been studies of the effects of pneumoperitoneum on the peritoneal cavity, we still do not know whether the morphologic changes to the peritoneum are different for pneumoperitoneum vs laparotomy. Using scanning electron microscopy, we examined the murine peritoneum after pneumoperitoneum vs laparotomy and compared the changes.

METHODS

Forty-five mice were anesthetized with diethyl ether and divided into seven groups. Pneumoperitoneum was established at 5 mmHg for 30 min with carbon dioxide (CO(2)) (n = 9), helium (n = 9), and air (n = 9). One group underwent laparotomy for 30 min (n = 9), and a control group underwent anesthesia only (n = 3). CO(2) pneumoperitoneum was further established at 10 mmHg for 30 min (n = 3) and at 5 mmHg for 60 min (n = 3). After the procedures, the peritoneum was resected from the mesenterium of the small intestine in each animal and examined by scanning electron microscope for morphologic changes of the mesothelial cells.

RESULTS

Bulging up of the mesothelial cells was evident immediately after pneumoperitoneum, whereas detachment of the mesothelial cells was present immediately after laparotomy. Bulging up of the mesothelial cells was reduced at 24 h after CO(2) pneumoperitoneum and fully resolved at 72 h in all pneumoperitoneum groups, whereas the mesothelial cells remained detached at 72 h in the laparotomy group. Intercellular clefts were found immediately after helium pneumoperitoneum and were present at 24 h and 72 h after helium pneumoperitoneum, but they were not seen after air pneumoperitoneum and were only evident after CO(2) pneumoperitoneum at 10 mmHg. Depression of the mesothelial cell surface was observed when pneumoperitoneum lasted 60 min.

CONCLUSION

Morphologic peritoneal alterations after pneumoperitoneum differed from those after laparotomy and were influenced by the type of gas, amount of pressure, and duration of insufflation. These peritoneal changes after pneumoperitoneum may be associated with a specific intraperitoneal tumor spread after laparoscopic cancer surgery.

Validation of a new experimental model of colon cancer

BACKGROUND

Most of the published animal studies that have evaluated tumor growth and port site metastases in laparoscopy have utilized a cell suspension model and thus cannot be compared to the clinical situation. Although solid tumor models have been developed, there has been no experimental model that establishes an orthotopic tumor in the rectum, reflecting the clinical situation of a solid colonic cancer.

METHODS

Tumor cells (colon adenocarcinoma DHD/K1/TRb) were administered intraperitoneally in rats, which were used as solid tumor donors. A 20-mg piece of solid tumor from the donor was placed in a submucosal blister created in the rectum wall of the study rats. The approach to the submucosal blister was made through the mucosa after contralateral enterotomy. In order to validate the model, this intervention was performed in 10 cases (group A). After 10 days of intervention, the rats were submitted to resection of the rectum and histological examination of the specimen. In another 10 rats (group B), manipulation of the tumor was performed after 10 days to cause tumor cell spillage. The likelihood of tumor dissemination was investigated in this group 20 days after this intervention.

RESULTS

Group A developed solid tumors in seven of 10 cases (70%). All of the tumors were localized between the muscular and the mucosal layer, with preservation of the serosa and without affecting the enterotomy. In all of the rats in group B, macroscopic tumor was observed in the upper rectum (100%) 10 days after its induction. Twenty days after tumor manipulation, nine rats had local tumor dissemination; two of them also had general tumor dissemination in the abdominal cavity.

CONCLUSIONS

We established a novel solid colonic tumor model in rats for the investigation of intraoperative tumor cell spillage during resection of the colon and the development of port site metastases.

Experimental assessment of tumor growth and dissemination of a microscopic peritoneal carcinomatosis after CO2 peritoneal insufflation or laparotomy

BACKGROUND

Based on clinical observations and previous animal studies, laparoscopic surgery for malignant disease is regarded as controversial. We used a rat model to measure and compare the tumor growth, proliferation, and dissemination of a microscopic peritoneal carcinomatosis after CO(2) intraperitoneal insufflation or laparotomy.

METHODS

Peritoneal carcinomatosis was induced in three groups of 27 BD IX rats each with intraperitoneal injections of 106 DHD/K12 cells, an aneuploid tumor cell line. At 48 h after tumor cell injection, the animals were randomly divided into three groups to undergo different types of intervention. All animals were anesthetized for 20 min (Halothane). The control group had no surgical intervention (group C), group I had CO(2) insufflation (7 mmHg),and group L had a midline laparotomy (5-cm). Neither bowel manipulation nor any other traumatic action was performed. Two weeks later, the rats were killed and the incidence, type, and dissemination of carcinomatosis were evaluated. We also measured the tumor's weight. Malignant omentum was sampled for flow cytometry analysis (DNA ploidy, S-phase fraction).

RESULTS

The incidence of carcinomatosis did not differ among the groups. The mean score of macroscopic characteristics of the carcinomatosis was 2.8 +/- 1.9 in group L, 2.9 +/- 1.9 in group I, and 3 +/- 1.9 in group C (NS). The location of the implants did not differ, except for parietal peritoneum location, which was more frequent in group L (p < 0.01). The tumor weight was 4.96 g +/- 3.2 in group L, 5.55 g +/- 3.2 in group C, and 5.75 g +/- 3.4 in group I (NS). The percentage of aneuploid cells and S-phase fraction did not differ statistically among the groups.

CONCLUSION

These results indicate that CO(2) insufflation does not cause more effects than laparotomy when tumors cells are present before the beginning of the surgery. Further studies are needed to determine the influence of other steps in laparoscopic surgery on tumor growth and dissemination.

The impact of laparoscopic biopsy of pancreatic lymph nodes with helium and carbon dioxide on port site and liver metastasis in BOP-induced pancreatic cancer in hamster

The influence of pancreatic biopsy during laparoscopy with carbon dioxide (CO2) and helium on the incidence of port site and liver metastasis in pancreatic carcinoma is still unknown. Ductal adenocarcinoma of the pancreas was induced in Syrian hamsters (n = 30) by injection of N-nitrosobis-2-oxopropylamin (BOP, 10 mg/kg body weight/week) for 12 weeks. In week 13, hamsters were randomized in 3 groups (n = 10): While in group 1 (gr. 1) a laparotomy and biopsy of pancreatic lymph nodes was performed, gr. 2 and gr. 3 underwent a laparoscopic biopsy either with CO2 or helium. Therefore, one trocar was located in the left (biopsy) and the right abdominal wall (camera). In the 18th week all animals were sacrificed and the incidence of abdominal wall, port site and liver metastases was histologically determined. While there were abdominal wall metastases after laparotomy in 10% (n = 1), we observed trocar metastases in the CO2 group in 20% (n = 2). However, there were no trocar metastases in the helium group. The incidence of liver metastasis did not differ between the laparotomy and the helium group (20% vs 30%), but was increased in the CO2 group (60%). Laparoscopic biopsy of pancreatic lymph nodes with CO2 increased the incidence of port site and liver metastases in pancreatic cancer. The helium group was equal to the laparotomy group in this respect. Thus, staging laparoscopy with helium might become an alternative to explorative laparotomy in pancreatic cancer.

Alterations in the immune system and tumor growth in laparoscopy

BACKGROUND

The explosion in the use of therapeutic laparoscopy during the past decade has focused much research interest on finding a basic scientific support for the clinically apparent attenuation of the stress response to surgery. In particular, the potential impact that attenuation of the immune response to surgery may have on laparoscopy for the cure of malignancy has attracted much attention.

METHODS

A review of the published literature on the stress response to laparoscopic surgery and the impact of laparoscopy on tumor growth was performed.

RESULTS

Evidence favors an attenuation of the immune response to surgery with laparoscopic cholecystectomy. Whether this is true also of more major procedures such as laparoscopically assisted colectomy for malignancy is currently unclear. In animal models, tumor growth after laparoscopic surgery is less than after laparotomy and depends on the insufflation agent used.

CONCLUSIONS

Laparoscopic cholecystectomy appears to be associated with attenuation of the immune response to surgery. The implications of these findings for the future use of laparoscopic surgical techniques for malignant disease remain unclear.

Effect of laparotomy and laparoscopy on the establishment of lung metastasis in a murine model

BACKGROUND

Laparoscopic surgery is now applied to patients with gastrointestinal cancer. In animal studies, extraperitoneal tumor growth has been significantly less after laparoscopy than after laparotomy, but whether hematogenous metastasis occurs less frequently after laparoscopy is unknown. The aim of this study was to compare the frequency and growth of lung metastasis and serum levels of IL-6 and tumor necrosis factor-alpha (TNF-alpha) in mice treated by laparotomy and in mice treated by laparoscopy.

METHODS

We used 182 male BALB/c mice. Colon 26 cancer cells (5 x 10(4)) were injected into the tail vein, and the mice were assigned to a laparotomy group (3-cm laparotomy), a laparoscopy group (carbon dioxide pneumoperitoneum at 6 to 8 mm Hg for 30 minutes), or a control group. Lung weight, number of lung metastases, and serum levels of IL-6 and TNF-alpha were measured and compared among the 3 groups.

RESULTS

The lung weight and number of metastases on the lung surface and cut section in the laparotomy group (0.44+/-0.21 g, 55.7+/-46.7, 23.0+/-19.0) were significantly larger than those in the laparoscopy group (0.32+/-0.15 g, 29.9+/- 25.5, 13.1+/-9.9) or the control group (0.28+/-0.13, 29.3+/-26.2, 11.1+/-11.1). Three hours after the procedures, the serum level of IL-6 was significantly higher in the laparotomy group (1353 +/- 790 pg/mL) than in the laparoscopy group (671+/-353 pg/mL) or the control group (333+/-341 pg/mL). The lung weight, number of lung metastases, and levels of IL-6 and TNF-alpha were not different between the laparoscopy and control groups.

CONCLUSIONS

Our results indicate that, although laparotomy accelerates tumor metastasis to the lung in this murine model, laparoscopy does not increase the frequency and growth of lung metastasis. The laparoscopic approach may suppress hematogenous metastasis to the lung because of decreased surgical stress and reduced cytokine response.

Cancer and laparoscopy, experimental studies: a review

OBJECTIVE

To review the experimental studies on laparoscopy and cancer and to propose guidelines for the clinical management of gynecologic cancer.

METHODS

The literature in MEDLINE was searched from January 1992 to December 1998 using the terms 'cancer', 'laparoscopy' and 'experimental or animal study'. Cross-referencing identified additional publications. Abstracts and letters to the editor were excluded. All the relevant papers were reviewed.

RESULTS

Depending on the model used, controversial results have been reported on the incidence of trocar site metastasis when comparing CO(2) laparoscopy and laparotomy. In contrast, the following conclusions can be proposed: (i) tumour growth after laparotomy is greater than after endoscopy; (ii) tumour dissemination is worse after CO(2) laparoscopy than after laparotomy; (iii) some of the disadvantages of CO(2) laparoscopy may be treated using local or intravenous treatments or avoided using other endoscopic exposure methods, such as gasless laparoscopy.

CONCLUSIONS

The laparoscopic treatment of gynecologic cancer has potential advantages and disadvantages, and may only be performed in prospective clinical trials. The risk of dissemination appears high when a large number of malignant cells are present. Adnexal tumours with external vegetations, and bulky lymph nodes should be considered as contra-indications to CO(2) laparoscopy.