Intraperitoneal cell movement during abdominal carbon dioxide insufflation and laparoscopy. An in vivo model

Port Site Metastasis in Women with Low- or Intermediate-Risk Endometrial Carcinoma: A Systematic Review of Literature

Background: Port site metastasis (PSM) has been reported as a rare metastasis in women with endometrial carcinoma (EC). However, even more rarely, it has also been described in patients with low- or intermediate-risk EC. Unfortunately, knowledge appears limited on the topic. Objectives: Our objective was to systematically review the literature on PSM in low- or intermediate-risk EC. Search Strategy: A systematic review of the literature was performed by searching six electronic databases from their inception to January 2023. Selection Criteria: We included in our research all peer-reviewed studies which reported PSM in low- or intermediate-risk EC women. Data Collection and Analysis: Data on PSM were collected from the included studies and compared. Results: Seven studies with 13 patients (including our case) were included in the systematic review. PSM was reported in patients with low- or intermediate-risk EC independently from tumor histologic characteristics, endoscopic approach, lymph node staging type, number and site of the port, route of specimen removal, prevention strategies for PSM, and concomitant metastases. Among several proposed treatments, local resection and radiotherapy with or without chemotherapy might be the most appropriate ones. Nevertheless, the prognosis appears poor. Conclusions: In patients with low- or intermediate-risk EC, PSM can occur as a rare metastasis, regardless of tumor characteristics or surgical strategy. Unfortunately, no consensus has been reached regarding treatment, and the prognosis appears poor. Additional cases are needed in order to confirm and further explore this rare EC metastasis.

Radial resection margin distinguishes between superficial versus deep resection in colorectal cancer: a retrospective study

Randomized studies showed that robotic surgery was short-term useful and safe for cancer patients. We investigated whether robots improve deep resection margins or superficial resection margins for radial resection margins in terms of short-term results. From an institutional database, we selected all superficial groups (≤ 3 mm) and deeper groups (≥ 4 mm) with rectal cancer treated with resection for a year. We evaluated the short-term post-operative 90-day outcomes on a radial resection size-based margin differentiation, including the first bowel movement, length of hospital stay, sepsis, and harvested lymph node. The main results were grades III-IV on the Clavien-Dindo scale and complications. We found 120 patients who had oncologic resection of rectal cancer; 42 patients with a superficial radial resection margin of ≤ 3 mm, all the following outcomes improved: the harvested lymph node, proximal resection margin, TME, flatus time, liquid diet duration, anastomotic leakage, and sepsis. Among these advantages were a reduced risk of metastasis and an overall reduction in local recurrence.

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.

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.

Current Evidence for Minimally Invasive Surgery During the COVID-19 Pandemic and Risk Mitigation Strategies: A Narrative Review

OBJECTIVE

Our objective was to review the literature surrounding the risks of viral transmission during laparoscopic surgery and propose mitigation measures to address these risks.

SUMMARY BACKGROUND DATA

The SARS-CoV-2 pandemic has caused surgeons the world over to re-evaluate their approach to surgical procedures given concerns over the risk of aerosolization of viral particles and exposure of operating room staff to infection. International society guidelines advise against the use of laparoscopy; however, the evidence on this topic is scant and recommendations are based on the perceived most cautious course of action.

METHODS

We conducted a narrative review of the existing literature surrounding the risks of viral transmission during laparoscopic surgery and balance these risks against the benefits of minimally invasive approaches. We also propose mitigation measures to address these risks that we have adopted in our institution.

RESULTS AND CONCLUSION

While it is currently assumed that open surgery minimizes operating room staff exposure to the virus, our findings reveal that this may not be the case. A well-informed, evidence-based opinion is critical when making decisions regarding which operative approach to pursue, for the safety and well-being of the patient, the operating room staff, and the healthcare system at large. Minimally invasive surgical approaches offer significant advantages with respect to both patient care, and the mitigation of the risk of viral transmission during surgery, provided the appropriate equipment and expertise are present.

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.

Glove and instrument changing to prevent tumour seeding in cancer surgery: a survey of surgeons' beliefs and practices

Background

Some surgeons change gloves and instruments after the extirpative phase of cancer surgery with the intent of reducing the risk of local and wound recurrence. Although this practice is conceptually appealing, the evidence that gloves or instruments act as vectors of cancer-cell seeding in the clinical setting is weak. To determine the potential effect of further investigation of this question, we surveyed the practices and beliefs of a broad spectrum of surgeons who operate on cancer patients.

Methods

Using a modified Dillman approach, a survey was mailed to all 945 general surgeons listed in the College of Physicians and Surgeons of Ontario public registry. The survey consisted of multiple-choice and free-text response questions. Responses were tabulated and grouped into themes, including specific intraoperative events and surgeon training. Predictive variables were analyzed by chi-square test.

Results

Of 459 surveys returned (adjusted response rate: 46%), 351 met the inclusion criteria for retention. Of those respondents, 52% reported that they change gloves during cancer resections with the intent of decreasing the risk of tumour seeding, and 40%, that they change instruments for that purpose. The proportion of respondents indicating that they take measures to protect the wound was 73% for laparoscopic cancer resections and 31% for open resections. Training and years in practice predicted some of the foregoing behaviours. The most commonly cited basis for adopting specific strategies to prevent tumour seeding was "gut feeling," followed by clinical training. Most respondents believe that it is possible or probable that surgical gloves or instruments harbour malignant cells, but that a cancer recurrence proceeding from that situation is unlikely.

Conclusions

There is no consensus on how gloves and instruments should be handled in cancer operations. Further investigation is warranted.

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.

Port-Site Metastases and Chimney Effect of B-Ultrasound-Guided and Laparoscopically-Assisted Hyperthermic Intraperitoneal Perfusion Chemotherapy

PURPOSE

CO₂ leakage along the trocar (chimney effect) has been proposed to be an important factor underlying port-site metastasis after laparoscopic surgery. This study aimed to test this hypothesis by comparing the incidence of port-site metastasis between B-ultrasound-guided and laparoscopically-assisted hyperthermic intraperitoneal perfusion chemotherapy (HIPPC).

MATERIALS AND METHODS

Sixty-two patients with malignant ascites induced by gastrointestinal or ovarian cancer were divided into two groups to receive either B-ultrasound-guided or laparoscopically-assisted HIPPC. Clinical efficacy was assessed from the objective remission rate (ORR), the Karnofsky Performance Status (KPS) score, and overall survival. The incidence of port-site metastasis was compared between the two groups.

RESULTS

Patients in the B-ultrasound (n=32) and laparoscopy (n=30) groups were comparable in terms of age, sex, primary disease type, volume of ascites, and free cancer cell (FCC)-positive ascites. After HIPPC, there were no significant differences between the B-ultrasound and laparoscopy groups in the KPS score change, ORR, and median survival time. The incidence of port-site metastasis after HIPPC was not significantly different between the B-ultrasound (3 of 32, 9.36%) and laparoscopy (3 of 30, 10%) groups, but significantly different among pancreatic, gastric, ovarian, and colorectal cancer (33.33, 15.79, 10.00, and 0.00%, p<0.001).

CONCLUSION

The chimney effect may not be the key reason for port-site metastasis after laparoscopy. Other factors may play a role, including the local microenvironment at the trocar site and the delivery of viable FCCs (from the tumor or malignant ascites) to the trauma site during laparoscopic surgery.

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.

Animal models of colorectal peritoneal metastasis

Colorectal cancer remains an important cause of mortality worldwide. The presence of peritoneal carcinomatosis (PC) causes significant symptoms and is notoriously difficult to treat. Therefore, informative preclinical research into the mechanisms and possible novel treatment options of colorectal PC is essential in order to improve the prognostic outlook in these patients. Several syngeneic and xenograft animal models of colorectal PC were established, studying a wide range of experimental procedures and substances. Regrettably, more sophisticated models such as those giving rise to spontaneous PC or involving genetically engineered mice are lacking. Here, we provide an overview of all reported colorectal PC animal models and briefly discuss their use, strengths, and limitations.

Analysis of open and intracorporeal robotic assisted radical cystectomy shows no significant difference in recurrence patterns and oncological outcomes

OBJECTIVES

To report and compare early oncological outcomes and cancer recurrence sites among patients undergoing open radical cystectomy (ORC) and robotic-assisted radical cystectomy with intracorporeal urinary diversion (iRARC).

METHODS AND MATERIALS

A total of 184 patients underwent radical cystectomy for bladder cancer. ORC cases (n = 94) were performed between June 2005 and July 2014 while iRARC cases (n = 90) were performed between June 2011 and July 2014. Primary outcome was recurrence free survival (RFS). Secondary outcomes were sites of local and metastatic recurrence, cancer specific survival (CSS) and overall survival (OS).

RESULTS

Median follow-up for patients without recurrence was 33.8 months (interquartile range [IQR]: 20.5-45.4) for ORC; and 16.1 months (IQR: 11.2-27.0) for iRARC. No significant difference in age, sex, precystectomy T stage, precystectomy grade, or lymph node yield between ORC and iRARC was observed. The ORC cohort included more patients with≥pT2 (64.8% ORC vs. 38.9% iRARC) but fewer pT0 status (8.5% ORC vs.vs. 22.2% iRARC) due to lower preoperative chemotherapy use (22.3% ORC vs. 34.4% iRARC). Positive surgical margin rate was significantly higher in the ORC cohort (19.3% vs. 8.2%; P = 0.042). Kaplan-Meir analysis showed no significant difference in RFS (69.5% ORC vs. 78.8% iRARC), cancer specific survival (80.9% ORC vs. 84.4% iRARC), or OS (73.5% ORC vs.vs. iRARC 83.8%) at 24 months. Cox regression analysis showed RFS, cancer specific survival and OS were not influenced by cystectomy technique. No significant difference between local and metastatic RFS between ORC and iRARC was observed.

CONCLUSION

This study has found no difference in recurrence patterns or oncological outcomes between ORC and iRARC. Recurrent metastatic sites vary, but are not related to surgical technique.

Minimally invasive versus the conventional open surgical approach of a radical cholecystectomy for gallbladder cancer: a retrospective comparative study

BACKGROUND

Laparoscopic surgery has traditionally been contraindicated for the management of gall bladder cancer (GBC). This study was undertaken to determine the safety and feasibility of a laparoscopic radical cholecystectomy (LRC) for GBC and compare it with an open radical cholecystectomy (ORC).

METHODS

Retrospective analysis of primary GBC patients (with limited liver infiltration) and incidental GBC (IGBC) patients (detected after a laparoscopic cholecystectomy) who underwent LRC between June 2011 and October 2013. Patients who fulfilled the study criteria and underwent ORC during the same period formed the control group.

RESULTS

During the study period, 147 patients with GBC underwent a radical cholecystectomy. Of these, 24 patients (primary GBC- 20, IGBC - 4) who underwent a LRC formed the study group (Group A). Of the remaining 123 patients who underwent ORC, 46 matched patients formed the control group (Group B). The median operating time was higher in Group A (270 versus 240 mins, P = 0.021) and the median blood loss (ml) was lower (200 versus 275 ml, P = 0.034). The post-operative morbidity and mortality were similar (P = 1.0). The pathological stage of the tumour in Group A was T1b (n = 1), T2 (n = 11) and T3 (n = 8), respectively. The median lymph node yield was 10 (4-31) and was comparable between the two groups (P = 0.642). During a median follow-up of 18 (6-34) months, 1 patient in Group A and 3 in Group B developed recurrence. No patient developed a recurrence at a port site.

CONCLUSION

LRC is safe and feasible in selected patients with GBC, and the results were comparable to ORC in this retrospective comparison.

Lung squamous cell carcinoma metastasizing to the nasopharynx following bronchoscopy intervention therapies: a case report

Metastatic carcinoma to the nasopharynx is extremely rare, and few cases have been reported in the literature. In the present report, we describe the case of a patient with a mass in the nasopharynx found by bronchoscopy. Our patient was a 61-year-old man receiving multiple bronchoscopy intervention therapies for advanced lung squamous cell carcinoma (SCC), which was histopathologically confirmed. The SCC metastasized to the nasopharynx following the bronchoscopy intervention therapies. The lesion was considered metastatic from lung cancer on the basis of clinical and histological clues. The exact mechanism of lung cancer metastasis to the nasopharynx in this case remains unclear because either implantation or hematogenous and lymphatic spread is possible. A thorough head and neck examination should be undertaken during bronchoscopic evaluation, especially in patients receiving bronchoscopy intervention therapies. The early detection of a silent nasopharyngeal metastasis is important to choosing from among the multiple treatment options available.

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.

Is laparoscopic colorectal cancer surgery equal to open surgery? An evidence based perspective

Laparoscopic colorectal surgery (LCS) is an evolving subject. Recent studies show that LCS can not only offer safe surgery but evidence is growing that this new technique can be superior to classical open procedures. Fewer perioperative complications and faster postoperative recovery are regularly mentioned when studies of LCS are presented. Even though the learning curve of LCS is frequently debated when limitations of laparoscopic surgeries are reviewed, studies show that in experienced hands LCS can be a safe procedure for colorectal cancer treatment. The learning curve however, is associated with high conversion rates and economical aspects such as higher costs and prolonged hospital stay. Nevertheless, laparoscopic colorectal cancer surgery (LCCR) offers several advantages such as less co-morbidity and less postoperative pain in comparison with open procedures. Furthermore, the good exposure of the pelvic cavity by laparoscopy and the magnification of anatomical structures seem to facilitate pelvic dissection laparoscopically. Moreover, recent studies describe no difference in safety and oncological radicalness in LCCR compared to the open total mesorectal excision (TME). The oncological adequacy of LCCR still remains unproven today, because long-term results do not yet exist. To date, only a few studies have described the results of laparoscopic TME combined with preoperative adjuvant treatment for colorectal cancer. The aim of this review is to examine the various areas of development and

controversy of LCCR in comparison to the conventional open approach.

The use of a wound protector to prevent port site recurrence may not be totally logical

The wound protector has been used widely to prevent port site metastases (PSM). Although port site metastases ties in with poor survival, it is not because of PSM itself, but rather because PSM is a sign of more widespread metastatic disease. Whilst being touted as a method of preventing PSM, it fails to address the bigger issue of preventing intra-abdominal recurrence. Proper surgical technique in tumour handling following rigorous oncological principles, and not just putting in a wound protector is the key to good surgery with low recurrences and excellent survival rates.

Technical innovation, standardization, and skill qualification for pediatric minimally invasive surgery in Japan

This is a presentation of sharing endeavors at modifying and standardizing surgical procedures as well as establishing endoscopic surgical skill qualification in the field of pediatric surgery in Japan.

Port site metastases

PURPOSE OF REVIEW

The aim of this article is to provide an overview of the incidence, pathophysiology, risk factors and possible methods of reducing the risk of port site metastases following uro-oncological procedures.

RECENT FINDINGS

To our knowledge, 28 cases of port site metastasis have been reported in the urologic literature. There has been an increased interest in the use of intraperitoneal instillation of various tumoricidals in order to reduce the risk of port site seeding.

SUMMARY

The risk of port site metastases remains low, provided that surgeons rigorously adhere to the principles of oncological surgery.

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.

Case Report: Port-Site Metastasis after Laparoscopic Radical Nephrectomy for Renal-Cell Carcinoma

A 65-year-old man with a 5.5 x 3.2-cm stage T(2)N(0)M(0) grade III renal-cell carcinoma suffered a port-site metastasis 8 months after laparoscopic radical nephrectomy with specimen removal in an organ-retrieval bag. This case underlines the need to be conversant with, and care to avoid, risk factors for this complication.

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.

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.

Effect of carbon dioxide pneumoperitoneum and wound closure technique on port site tumor implantation in a rat model

BACKGROUND

The purpose of this study was to evaluate the effects of carbon dioxide (CO2) pneumoperitoneum and wound closure technique on port site tumor implantation.

METHODS

A standard quantity of rat mammary adenocarcinoma (SMT2A)was allowed to grow in a flank incision in Wistar-Furth rats (n = 90) for 14 days. Thereafter, 1-cm incisions were made in each animal in three quadrants. There were six control animals. The experimental animals were divided into a 60-min CO2 pneumoperitoneum group (n = 42) and a no pneumoperitoneum (n = 42) group. The flank tumor was lacerated transabdominally in the experimental groups. The three wound sites were randomized to closure of (a) skin; (b) skin and fascia; and (c) skin, fascia, and peritoneum. The abdominal wounds were harvested en bloc on postoperative day 7.

RESULTS

Histologic comparison of the port sites in the pneumoperitoneum and no-pneumoperitoneum groups did not demonstrate a statistically significant difference in tumor implantation for any of the closure methods. Evaluation of the closure techniques showed no statistical difference between the pneumoperitoneum group and the no-pneumoperitoneum group in the incidence of port site tumor implantation. Within the no-pneumoperitoneum group, there was a significant increase (p = 0.03) in tumor implantation with skin closure alone vs all three layers. Additionally, when we compared all groups by closure technique, the rate of tumor implantation was found to be significantly higher (p = 0.01) for skin closure alone vs closure of all three layers.

CONCLUSIONS

This study suggests that closure technique may influence the rate of port site tumor implantation. The use of a CO2 pneumoperitoneum did not alter the incidence of port site tumor implantation at 7 days postoperatively.

Unexpected metastatic lobular carcinoma of the breast with intraabdominal spread and subsequent port-site metastasis after diagnostic laparoscopy for exclusion of ovarian cancer

INTRODUCTION

Although lobular carcinomas metastasize primarily to lymph nodes, bone, lung and liver, they can also spread to the gastrointestinal tract, peritoneum and gynecologic organs.

CASE REPORT

We report a case of intraperitoneal carcinomatosis of a lobular breast carcinoma that metastasized primarily to the peritoneum, with a subsequent abdominal wall invasion at the trocar site following laparoscopic surgery for the exclusion of an ovarian carcinoma.

DISCUSSION

Port-site metastases (PSM) have occurred after laparoscopic surgery for endometrial, fallopian tube, ovarian, and cervical cancers. This is the first report of PSM of a lobular breast carcinoma primarily metastasized to the abdominal cavity. Every surgeon should be aware of the metastatic pattern of breast cancer, especially in relation to its histological subtypes. This case report emphasizes that PSM can occur in various kinds of gynecologic tumors, including breast cancer.

Irrigation of port sites: prevention of port site metastases?

INTRODUCTION

Port site metastases can occur when free viable tumor cells implant at trocar wounds. Irrigation of port sites with cytotoxic agents has been suggested to prevent port site metastases. The objective of this study is to assess whether tumor growth at port sites can be reduced by irrigation of these port sites.

METHODS

WAG rats were insufflated with CO(2) for 20 minutes and 5 x 10(5) CC531 tumor cells were injected intraperitoneally. Port sites were irrigated after completion of the pneumoperitoneum with povidone-iodine, a mixture of taurolidine and heparin, or sodium chloride. Controls did not undergo any irrigation of port sites. In experiment 1, all 16 rats had all 4 irrigation modalities. In experiment 2, four groups of 20 rats had one type of irrigation on two trocar wounds. Tumor growth was evaluated 4 weeks after the procedure.

RESULTS

No difference in tumor growth at trocar wounds was found between any type of irrigation and controls in both experiments.

CONCLUSION

In this experimental model, no beneficial or adverse effects of irrigation of port sites could be shown.

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.

Pneumoperitoneum and peritoneal surface changes: a review

BACKGROUND

Recent evidence suggests that the use of carbon dioxide to create a pneumoperitoneum during laparoscopy can lead to adverse structural, metabolic, and immune derangements within the peritoneal cavity, and that these can be dependent on the specific insufflation gas used. These changes include structural alterations in the mesothelial lining, pH disturbances, and alterations in peritoneal macrophage responsiveness. This contrasts with an apparent systemic benefit associated with laparoscopic, as compared with open, surgery.

METHODS

Recently published clinical and experimental studies related to the effect of pneumoperitoneum on the peritoneal surface are reviewed, and their relevance is discussed.

RESULTS

Structural changes in the peritoneal mesothelial surface layer such as widening of the intercellular junctions can be demonstrated with electron microscopy. Acidification of the peritoneum in response to carbon dioxide insufflation occurs not only at the peritoneal surface, but also in the underlying connective tissue, resulting in disturbances in the electrical surface charge and the release of various immune mediators such as endotoxin. Pneumoperitoneum also affects the local peritoneal immune environment resulting in alterations in cytokine production and phagocytic function, as well as diminished antitumor cell cytotoxicity.

CONCLUSIONS

Ultrastructural, metabolic, and immune alterations are observed at the peritoneal surface in response to a pneumoperitoneum. Experimental evidence suggests that these changes are carbon dioxide-specific effects. The consequences of these alterations to the local peritoneal environment are not well understood, but they may facilitate tumor implantation within the peritoneal cavity and adversely affect the ability to clear intraperitoneal infections. Further investigation into this area is warranted.

Colon cancer cell adhesion in response to Src kinase activation and actin-cytoskeleton by non-laminar shear stress

Malignant cells shed from tumors during surgical resection or spontaneous metastasis experience physical forces such as shear stress and turbulence within the peritoneal cavity during irrigation, laparoscopic air insufflation, or surgical manipulation, and within the venous or lymphatic system. Since physical forces can activate intracellular signals that modulate the biology of various cell types in vitro, we hypothesized that shear stress and turbulence might increase colon cancer cell adhesion to extracellular matrix, potentiating metastatic implantation. Primary human malignant colon cancer cells isolated from resected tumors and SW620 were subjected to shear stress and turbulence by stirring cells in suspension at 600 rpm for 10 min. Shear stress for 10 min increased subsequent SW620 colon cancer cell adhesion by 40.0 +/- 3.0% (n = 3; P < 0.001) and primary cancer cells by 41.0 +/- 3.0% to collagen I when compared to control cells. In vitro kinase assay (1.5 +/- 0.13 fold) and Western analysis (1.34 +/- 0.04 fold) demonstrated a significant increase in Src kinase activity in cells exposed shear stress. Src kinase inhibitors PP1 (0.1 microM), PP2 (20 microM), and actin-cytoskeleton stabilizer phalloidin (10 microM) prevented the shear stress stimulated cell adhesion to collagen I. Furthermore, PP2 inhibited basal (50.0 +/- 2.8%) and prevented shear stress induced src activation but phalloidin pretreatment did not. These results raise the possibility that shear stress and turbulence may stimulate the adhesion of malignant cells shed from colon cancers by a mechanism that requires both actin-cytoskeletal reorganization an independent physical force activation of Src kinase. Blocking this pathway might reduce tumor metastasis during surgical resection.

The effects of staging laparoscopy on trocar site and peritoneal recurrence of pancreatic cancer

BACKGROUND

Staging laparoscopy (SL) has been used to assess resectability of patients with pancreatic cancer. It has lead to increased resectability rates and decreased morbidity. However, experimental data suggests that laparoscopy and peritoneal insufflation can promote tumor growth and potential recurrence. Few clinical data exist to allow assessment of whether these theoretical concerns translate into clinical problems. The purpose of this study was to determine if SL increases the incidence of trocar-site and peritoneal recurrence of pancreatic cancer.

METHODS

A retrospective review of all patients evaluated for pancreatic cancer from 1996 to 2001, inclusive, was included in this study. Patients were divided into five groups: nonoperative management (NM), SL followed by resection (SL-R), SL without resection (SL-NR), exploratory laparotomy with resection (EL-R), and exploratory laparotomy without resection (EL-NR). Patient records were assessed for postoperative occurrence of carcinomatosis and/or malignant ascites, trocar- or incisional-site recurrence, use of postoperative chemotherapy or radiation therapy, and survival.

RESULTS

A total of 235 patients were included. Peritoneal progression of disease: NM 15.9%, SL 24.2%, EL 31.6% ( p = 0.03). Trocar/incisional recurrence: SL 3.0%, EL 3.9% ( p = NS). Use of chemotherapy/radiotherapy: NM 29.4%, SL-R 76.5%, SL-NR 62.5%, EL-R 69.6%, EL-NR 41.5%. Median survival (months): NM 3; SL-R 15, EL-R 10 ( p = NS); SL-NR 6, EL-NR 5 ( p = NS).

CONCLUSION

SL does not increase the occurrence of trocar-site disease or peritoneal disease progression of pancreatic cancer. Patients who are found not to be resectable by SL are more likely to receive postoperative treatment. However, this does not appear to affect survival greatly. Nevertheless, avoidance of nontherapeutic laparotomy is worthwhile in these patients.

Laparoscopic total mesorectal excision (TME) for rectal cancer surgery: long-term outcomes

BACKGROUND

Total mesorectal excision (TME) offers the lowest reported rates of local recurrence and the best survival results in patients with rectal cancer. However, the laparoscopic approach to resection for colorectal cancer remains controversial due to fears that oncologic principles will be compromised. We assessed the feasibility, safety and long-term outcome of laparoscopic rectal cancer resections following the principles of TME. The aim of this study was to evaluate the perioperative outcome and long-term results of laparoscopic TME.

METHODS

We reviewed the prospective database of 102 consecutive unselected patients undergoing laparoscopic TME for rectal cancer between November 1991 and December 2000. Follow-up was done through office charts or direct patient contact. Recurrence and survival curves were generated by the Kaplan-Meier method.

RESULTS

Laparoscopic TME was completed successfully in 99 patients, whereas conversion to an open approach was required in three cases (3%). The overall morbidity and mortality rates were 27% and 2%, respectively, with an overall anastomotic leak rate of 17%. Of the 102 patients, four were excluded from the oncologic evaluation because final pathology was not confirmatory (two had anal canal squamous cell carcinoma and two had villous adenoma with dysplasia). In 90 of the 98 remaining patients (91.8%), the resection was considered curative. The remainder had a palliative resection due to synchronous metastatic disease or locally advanced disease. Mean follow-up was 36 months (range, 6-96). There were no trocar site recurrences. The local recurrence rate was 6%, and the cancer-specific survival of all curatively resected patients was 75% at 5 years. The overall survival rate of all curatively resected patients was 65% at 5 years; mean survival time was 6.23 years (95% confidence interval [CI], 5.39-7.07).

CONCLUSION

Laparoscopic TME is feasible and safe. The laparoscopic approach to the surgical treatment of operable rectal cancer does not seem to entail any oncologic disadvantages.

Hand Port-Site Metastasis of Renal-Cell Carcinoma Following Hand-Assisted Laparoscopic Radical Nephrectomy: Case Report

A 66-year-old man underwent hand-assisted laparoscopic radical nephrectomy (HALN) for a 10 x 7-cm, stage T(2)N(0)M(0) right-sided renal-cell carcinoma. Nine months later, tumor recurrence was noted at the previous hand port site. This is the first case report of such a metastasis. Possible mechanisms for tumor metastasis are reviewed, and preventive strategies are suggested.

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.

COLOR: a randomized clinical trial comparing laparoscopic and open resection for colon cancer

BACKGROUND

Laparoscopic surgery has proven to be safe and effective. However, the value of laparoscopic resection for malignancy in terms of cancer outcome can only be assessed by large prospective randomized clinical trials with sufficient follow-up.

METHODS

COLOR (COlon carcinoma Laparoscopic or Open Resection) is a European multicenter randomized trial that began in 1997. In 27 hospitals in Sweden, The Netherlands, Germany, France, Italy, Spain, and the United Kingdom, 1200 patients will be included. The primary endpoint of the study is cancer-free survival after 3 years.

RESULTS

In <3.5 YEARS, >850 patients have been randomized for right hemicolectomy (47%), left hemicolectomy (11%), and sigmoidectomy (42%). Fifty seven patients were excluded after randomization. Forty six months after the start of the trial, the overall recurrence rate is 6.8%. The distribution of stage of disease is as follows: stage I, 25%; stage II, 41%; stage III, 32%; stage IV, 2%.

CONCLUSION

Although laparoscopic surgery appears to be of value in the treatment of colorectal cancer, the final, results of randomized trials need to be considered to determine its definitive role. Given the current accrual rate, the COLOR study will be completed in 2002.

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.