Abdominal incision tumor implantation following pneumoperitoneum laparoscopic procedure vs. standard open incision in a syngeneic rat model

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

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

Port site metastasis after surgery for renal cell carcinoma: harbinger of future metastasis

PURPOSE

Port site metastasis is a rare occurrence after minimally invasive treatment for renal cell carcinoma. However, its prognostic implications are unclear because reports in the literature are heterogeneous in detail and followup. We clarify the significance of port site metastasis in cancer specific survival and broaden our understanding of this phenomenon.

MATERIALS AND METHODS

A MEDLINE® search for published studies of renal cell carcinoma port site metastasis was performed. Contributing factors to port site metastasis, stage, Fuhrman grade, pathology, port site metastasis treatment method, followup protocol and long-term outcomes were collected. The corresponding authors of each publication were contacted to fill in details and provide long-term outcomes. We added 1 case from our recent experience.

RESULTS

A total of 16 cases from 12 authors (including ourselves) were found. Of the 12 authors 8 were available for correspondence and 9 cases were updated. Eventual outcomes were available for 11 of the 16 cases and survival curves showed poor prognosis with a 31.8% overall 1-year survival rate. Of the 16 cases 12 were radical nephrectomy and 4 were partial nephrectomy, and 13 involved multiple metastases in addition to the port site metastasis. Nine of the cases had no identifiable technical reason for port site metastasis formation such as specimen morcellation, absence of entrapment or tumor rupture. These tumors were uniformly aggressive, Fuhrman grade 3 or higher.

CONCLUSIONS

Port site metastasis after minimally invasive surgery for renal cell carcinoma is a rare occurrence with a poor prognosis. In most cases port site metastasis is not an isolated metastasis but instead is a harbinger of progressive disease. While technical factors can have a role in port site metastasis formation, it appears that biological factors like high tumor grade also contribute.

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

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

Influence of CO2 pneumoperitoneum on intracellular pH and signal transduction in cancer cells

OBJECT

The authors studied the influence of CO(2) pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation.

METHOD

They set up a simulation of pneumoperitoneum under different CO(2) pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated.

RESULT

When the pressure of CO(2) pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5, 178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15 x 10(5), 2.03 x 10(5), 2.20 x 10(5), 2.18 x 10(5) L(-1).

CONCLUSION

CO(2) pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.

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.

Tumour seeding in peritoneal wound sites in relation to growth-factor expression in early granulation tissue

The purpose of these experiments was to identify growth factors produced during the formation of a peritoneal wound in relation to tumour cell seeding and stimulated growth in granulation tissue. Gelfoam(c) gelatin sponge was implanted in the mesenteric fan of nude mice to initiate the granulation process. Human HT29 colon carcinoma cells were inoculated intraperitoneally at various times after sponge implantation and tumour growth in granulation tissue was determined. RNA isolated from granulation tissue was used for polymerase chain reaction analysis of the expression of specific growth factors and receptors [vascular endothelial growth factor (VEGF), transforming growth factor-beta (TGF-beta) and lysophosphatic acid (LPA)], and for microarray analysis of differentially expressed genes in early vs. late granulation tissue. Inflammatory cells infiltrated the sponge within 1 day, followed by fibroblasts and the formation of an extracellular matrix. Tumour cell inoculation at 8 h to 3 days after sponge implantation resulted in extensive tumour formation in all cases. Inoculation at 10-28 days resulted in focal tumour growth in only 16-33% of the sponges. Low amounts of VEGF, TGF-beta(1-3), TGF-beta RIII and LPA receptors 1,2 were detected in early granulation tissue, with increased expression from day 10. Microarray analysis identified additional differentially expressed genes that may stimulate tumour take and growth in early granulation tissue.

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.

Effects of carbon dioxide and nitrogen on adhesive growth and expressions of E-cadherin and VEGF of human colon cancer cell CCL-228

AIM: To study the effects of carbon dioxide on the metastatic capability of cancer cells, and to compare them with that of nitrogen.

METHODS: The colon cancer cell CCL-228 was treated with 100% carbon dioxide or nitrogen at different time points and then cultured under normal condition. Twelve hours after the treatment, the survival rates of suspension cells and the expressions of e-cadherin and VEGF were examined.

RESULTS: After 60 min of carbon dioxide and longer time of nitrogen treatment, the suspended cells increased and the expression of e-cadherin decreased while the expression of VEGF was enhanced significantly. And the effects of nitrogen were similar to, but weaker than, those of carbon dioxide.

CONCLUSION: Carbon dioxide may improve the metastatic capability of cancer cells and its effects are significantly stronger than that of nitrogen. A sequential use of carbon dioxide and nitrogen in pneumoperitoneum may take the advantage of both gases.

An orthotopic nude mouse model for evaluating pathophysiology and therapy of pancreatic cancer

INTRODUCTION

Orthotopic, clinically relevant animal models are necessary for the study of pathophysiology and therapy for pancreatic cancer.

AIMS

To develop a minimally traumatic technique of orthotopic tumor induction, to develop a scoring system to quantify local and systemic tumor spread, and to provide a model with a broad range of well-differentiated to undifferentiated pancreatic cancers.

METHODOLOGY

Orthotopic tumors were induced in nude mice by atraumatic pancreatic implantation of two fragments from subcutaneous donor tumors or intrapancreatic injection of human tumor cells (MIAPaCa-2, AsPC-1, HPAF-2, Capan-1). Animals were monitored for 14 weeks or until death. Primary tumor volume, local infiltration, and systemic metastasis were assessed and analyzed at autopsy. Macroscopic findings were confirmed by histologic evaluation.

RESULTS

Tumor take rate in the implantation group was 100% for all four cell lines. Marked differences with regard to tumor size, metastatic spread, and survival were found depending on the grade of differentiation. Less differentiated cells (MIAPaCa-2, AsPC-1) caused higher dissemination scores and mortality than better-differentiated cells (HPAF-2, Capan-1). Clinical features included cachexia, jaundice, and malignant ascites. Orthotopic tumor cell injection resulted in an incomplete tumor take rate. Moreover, early artificial abdominal tumor spread was found in injected animals due to microscopic cell loss during the injection procedure.

CONCLUSIONS

Orthotopic implantation of donor tumor fragments into nude mice is technically feasible and is superior to the cell injection technique. It results in reproducible local and systemic development of pancreatic cancer that mimics the human disease. A dissemination score may help to better quantify therapeutic effects in future studies.

Laparoscopic total mesorectal excision: a consecutive series of 100 patients

OBJECTIVE

To analyze total mesorectal excision (TME) for rectal cancer by the laparoscopic approach during a prospective nonrandomized trial.

SUMMARY BACKGROUND DATA

Improved local control and survival rates in the treatment of rectal cancer have been reported after TME.

METHODS

The authors conducted a prospective consecutive series of 100 laparoscopic TMEs for low and mid-rectal tumors. All patients had a sphincter-saving procedure. Case selection, surgical technique, and clinical and oncologic results were reviewed.

RESULTS

The distal limit of rectal neoplasm was on average 6.1 (range 3-12) cm from the anal verge. The mean operative time was 250 (range 110-540) minutes. The conversion rate was 12%. Excluding the patient who stayed 104 days after a severe fistula and reoperation, the mean postoperative stay was 12.05 (range 5-53) days. The 30-day mortality was 2% and the overall postoperative morbidity was 36%, including 17 anastomotic leaks. Of 87 malignant cases, 70 (80.4%) had a minimum follow-up of 12 months, with a median follow-up of 45.7 (range 12-72) months. During this period 18.5% (13/70) died of cancer and 8.5% (6/70) are alive with metastatic disease. The port-site metastasis rate was 1.4% (1/70): a rectal cancer stage IV presented with a parietal recurrence at 17 months after surgery. The locoregional pelvic recurrence rate was 4.2% (3/70): three rectal cancers stage III at 19, 13, and 7 postoperative months.

CONCLUSIONS

Laparoscopic TME is a feasible but technically demanding procedure (12% conversion rate). This series confirms the safety of the procedure, while oncologic results are at present comparable to the open published series with the limitation of a short follow-up period. Further studies and possibly randomized series will be necessary to evaluate long-term clinical outcome in cancer patients.

Laparoscopic surgery for colorectal carcinoma. an overnight victory?

Laparoscopic surgery became popular in the early 1990s. Cholecystectomy was the first 'victim' conquered by the new technique and laparoscopic cholecystectomy became the gold standard operation for gallbladder stones. Laparoscopic colorectal surgery was then attempted, for both benign and malignant disorders. After a short period of enthusiasm, alarming reports were published on laparoscopic surgery for malignant disease. The occurrence of so called 'port-site' metastases (PSM) led to a reduction in the use of the minimal invasive technique. In addition, the duration of the operations was criticised, as well as the limited beneficial effects (if any) and the possible violation of oncological surgical principles. The pros and cons of this new technique during its introduction are discussed, with focus on problem areas such as port-site metastases, surgical learning curve as well as beneficial effects. The current status of several comparative studies evaluating the laparoscopic technique is discussed leading to the conclusion that a basis for further research exists and therefore cautious progress is warranted.

Hand-assisted laparoscopic surgery for cancer

Minimally invasive surgical approaches were designed to enhance quality of care and improve patient outcome by minimizing postoperative pain, shortening hospital stay, reducing costs, and facilitating early return to work and presurgical lifestyle. The hand-assisted laparoscopic approach for resection of cancer is still in its formative stage, and this review places it in proper perspective within the context of minimally invasive surgery currently being performed for both benign and malignant disease. The review also outlines the potential advantages and disadvantages, techniques, and site-specific procedures of hand-assisted laparoscopic surgery for cancer.

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.

Port site metastases after laparoscopic lymph node staging of cervical carcinoma

The literature revealed only six cases of cervical carcinoma metastatic to a port site after laparoscopic lymphadenectomy. A woman with a poorly differentiated squamous cell carcinoma of the cervix had port site metastases after laparoscopic lymph node staging. The frequency of this event might be higher than expected. Therefore, surgeons should reduce mechanical irritation of port sites and spillage of tumor cells.

Influence of peritoneal factors on port-site metastases in a xenograft ovarian cancer model

OBJECTIVE

We determine the main physical effects of pneumoperitoneum on tumour dissemination and port-site metastases occurrence.

DESIGN

A prospective randomised study in rats.

METHODS

A human ovarian cancer cell line (IGR-OV1) was xenografted in nude rats. Seven days after cancer inoculation, surgery was performed. Rats were randomised in two main groups and underwent either: gasless laparoscopy (n = 20) CO2 laparoscopy with pneumoperitoneum pressure at 4 mmHg (n = 20), or 8 mmHg (n = 20) with in each case, increasing operative duration: 30,60,90 or 120 minutes (five rats for each time). Animals were killed seven days after the intervention.

MAIN OUTCOME MEASURES

Tumour dissemination and frequency of port-site metastases.

RESULTS

Tumour dissemination was not influenced by gas pressures or duration of procedure. The rate of rats with at least one port-site metastasis (one or two) was similar in all groups: gasless: n = 10/20; 4 mmHg CO2: 5/20; 8 mmHg CO2: 7/20,(P = 0.26). The number of port-site metastases were significantly higher in the gasless group compared with the 4 mmHg CO2 group (15/40 (37.5%) vs 5/40 (12.5%), P = 0.01). Difference was not significant between the 8mmHg group and the gasless group (9/40(22.5%) vs 15/40(37.5%), P = 0.14) or the 4mmHg group (9/40(37.5%) vs 5/40 (12.5%), P = 0.24). Duration of procedures had no significant influence on port-site metastases rate (P > 0.05).

CONCLUSIONS

Unlike previous animal studies, port-site metastases were more frequent with gasless laparoscopy than with CO2 pneumoperitoneum. Local peritoneal factors could play an important role in port-site metastases mechanism.

Trocar site recurrence in laparoscopic surgery for colorectal cancer

BACKGROUND

Laparoscopic colorectal surgery has been associated with less postoperative pain, an early return of bowel function, a shorter period of hospitalization and disability, and better cosmetic results. However, the application of laparoscopic techniques to the curative resection of colorectal cancer is still controversial, owing to reports of cancer recurrence at the port site wounds. The accumulation of numerous such reports in a relatively short period raised concern that there might be an extraordinary high rate of port site metastases after laparoscopic colorectal surgery. This concern has led to intense clinical and basic research aimed at determining the incidence and causes of wound recurrence and developing preventative measures to address this problem. Despite these efforts, it is still not clear whether port site metastasis is really an inherent drawback to laparoscopic cancer surgery.

METHODS

In this review of the literature on port site metastasis, we gathered data from clinical series of laparoscopic surgery for colorectal cancer. We eliminated series of <50 patients, since they may be flawed by the learning curve required for this technically demanding procedure.

RESULTS

The rate of port site recurrences in the 1737 patients who participated in these series was 1%. Although the methods and criteria for patient selection in these studies varied, this figure appears to be comparable to the incidence reported for other malignancies and for laparotomies performed to treat colorectal cancer.

CONCLUSION

This review suggests that wound recurrence may actually be the result of an unfortunate learning curve, rather than an inherent concern. However, we must await the final results of large randomized studies before drawing any definitive conclusions.

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.

An improved clinical model of orthotopic pancreatic cancer in immunocompetent Lewis rats

The study of pancreatic cancer (PaCa) requires orthotopic, clinically relevant animal models. The aims of this study were to establish an orthotopic model of ductal pancreatic adenocarcinoma in immunocompetent Lewis rats and to develop a scoring system to quantify local tumor infiltration and distant metastasis. Cells (10(7)) of the rat ductal PaCa cell line DSL-6A/C1 were injected s.c. into donor rats. After 8 weeks, either three (IPL-3) or five (IPL-5) fragments (1 mm3) of the resulting s.c. tumors were microsurgically implanted into the pancreas of recipient rats. In another series of animals, 10(7) DSL-6A/C1 cells were directly injected (INJ) into the pancreas. All animals were monitored daily until death or for 16 weeks. At autopsy, volume of primary tumors and ascites, local and systemic tumor spread, and histologic phenotype were assessed. IPL-5 resulted in significantly larger tumors (12,224 +/- 1,933 mm3), more local infiltration and systemic spread (score: 18.3 +/- 2.0 points), severe clinical tumor disease, and lethality (50%) in comparison to the other induction techniques (IPL-3: 283 +/- 115 mm3/3.5 +/- 0.8 points/0; INJ: 752 +/- 207 mm3/4.3 +/- 0.8 points/8%). Histologic examination revealed moderately to well-differentiated ductal tumors, surrounded by dense stroma. Intraperitoneal tumor dissemination in the INJ group occurred simultaneous with primary tumor growth, indicating PaCa cell spread during injection. Orthotopic implantation of five DSL-6A/C1 tumor fragments into the rat pancreas provides a valid clinical model of ductal pancreatic adenocarcinoma in immunocompetent rodents for preclinical treatment studies. The dissemination score we used permitted quantification of local and systemic tumor spread.

Effects of topical tumoricidal agents on port-site recurrence of colon cancer: an experimental study in rats

BACKGROUND

Reports of metastatic spread of colon and rectal cancer to port sites after laparoscopic resection of potentially curable lesions has raised doubt regarding the efficacy and safety of laparoscopic technology in cancer surgery. Experimental study in animals has led us to believe that the mode of spread of these metastases is via the direct route. We hypothesized, therefore, that we could decrease the rate of trocar-site recurrences by treating the individual port sites with a topical tumoricidal agent.

MATERIALS AND METHODS

Male BD-IX rats weighing 240 to 360 g were injected with syngeneic colon cancer to simulate free intraperitoneal cancer spread to trocar sites. All rats were subjected to a sham laparoscopic operation after 2 x 10(5) viable cancer cells had been injected into their peritoneal cavities. Five-millimeter trocars were inserted into each rat after abdominal insufflation to 10 mm Hg. Pneumoperitoneum was maintained for 10 minutes before the trocars were removed simultaneously. Trocar sites were then subjected to one of three treatments, with each animal receiving a maximum of two different treatments. Sites were treated with 70% ethanol (N = 42), povidine/ iodine (N = 40), or no topical treatment (N = 46). Three weeks later, the animals were euthanized and autopsied. Subcutaneous tumors at trocar sites or tumors with >50% volume within the wound were considered implants.

RESULTS

Control sites revealed a metastasis rate of 41% (19/46). The tumor implant rate was 36% (15/42) at alcohol-treated sites and 20% (8/40) at sites treated with povidone-iodine (P < 0.05).

CONCLUSION

Topical administration of povidone-iodine to trocar wounds after laparoscopic surgery can significantly reduce the incidence of port-site metastasis in a syngeneic animal model of colon cancer.

Patterns of recurrence and survival after laparoscopic and conventional resections for colorectal carcinoma

OBJECTIVE

To determine whether survival and recurrence after laparoscopic-assisted surgery for colorectal cancer is compromised by an initial laparoscopic approach.

SUMMARY BACKGROUND DATA

Laparoscopic colorectal resection for malignancy remains controversial 8 years after its first description. Fears regarding compromised oncologic principles and early recurrence (particularly the phenomenon of port-site metastases) have tempered enthusiasm for this approach. Long-term follow-up data are at present scarce.

METHODS

A prospective comparative trial was undertaken between December 1993 and May 1996, during which 114 patients had laparoscopic-assisted resection by a single laparoscopic colorectal surgeon or conventional open surgery by a second specialist colorectal surgeon. Intensive follow-up for at least 2 years is available on 109 patients. Analysis was performed on an intention-to-treat basis.

RESULTS

Recurrent disease has developed in 27 patients (25%), 16 of 57 in the laparoscopic group (28%) and 11 of 52 in the conventional group (21%). Crude death rates are 26/57 (46%) in the laparoscopic group and 24/52 (46%) in the conventional group. No port-site metastases have occurred; however, wound metastases associated with disseminated disease have developed in three patients in the open group and one in the laparoscopic group. Stage-for-stage survival and recurrence figures are comparable.

CONCLUSION

Oncologic outcome at a minimum of 2 years is not compromised by the laparoscopic approach. Wound recurrences are a feature of laparoscopic and conventional surgery for advanced disease.

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.