Possible effect of pneumoperitoneum on the spreading of colon cancer tumor cells

Severe portal and systemic acidosis during CO2-laparoscopy compared to helium or gasless laparoscopy and laparotomy in a rodent model: an experimental study

BACKGROUND AND AIMS

This experimental study assesses the influence of different gases and insufflation pressures on the portal, central-venous and peripheral-arterial pH during experimental laparoscopy.

METHODS

Firstly, 36 male WAG/Rij rats were randomized into six groups (n = 6) spontaneously breathing during anaesthesia: laparoscopy using carbon dioxide or helium at 6 and 12 mmHg, gasless laparoscopy and laparotomy. 45 and 90 min after setup, blood was sampled from the portal vein, vena cava and the common femoral artery with immediate blood gas analysis. Secondly, 12 animals were mechanically ventilated at physiological arterial pH during 90 min of laparotomy (n = 6) or carbon dioxide laparoscopy at 12 mmHg (n = 6) with respective blood gas analyses.

RESULTS

Over time, in spontaneously breathing rats, carbon dioxide laparoscopy caused significant insufflation pressure-dependent portal acidosis (pH at 6 mmHg, 6.99 [6.95-7.04] at 45 min and 6.95 [6.94-6.96] at 90 min, pH at 12 mmHg, 6.89 [6.82-6.90] at 45 min and 6.84 [6.81-6.87] at 90 min; p < 0.05) compared to laparotomy (portal pH 7.29 [7.23-7.30] at 45 min and 7.29 [7.20-7.30] at 90 min; p > 0.05). Central-venous and peripheral-arterial acidosis was significant but less severely reduced during carbon dioxide laparoscopy. Laparotomy, helium laparoscopy and gasless laparoscopy showed no comparable acidosis in all vessels. Portal and central-venous acidosis during carbon dioxide laparoscopy at 12 mmHg was not reversible by mechanical hyperventilation maintaining a physiological arterial pH (pH portal 6.85 [6.84-6.90] (p = 0.004), central-venous 6.93 [6.90-6.99] (p = 0.004), peripheral-arterial 7.29 [7.29-7.31] (p = 0.220) at 90 min; Wilcoxon-Mann-Whitney test).

CONCLUSION

Carbon dioxide laparoscopy led to insufflation pressure-dependent severe portal and less severe central-venous acidosis not reversible by mechanical hyperventilation.

Impact of circulating tumor cells in colorectal cancer patients undergoing laparoscopic surgery

Laparoscopic surgery has recently been widely used for various benign colorectal diseases as well as colorectal cancer. Although laparoscopic surgery has been shown to be with similar prognostic results for certain groups of colorectal cancer patients. The influence of laparoscopic procedures on the oncologist results, especially free tumor cell spreading is still a concern for some surgeons. Tumor cells found in the peripheral blood of patients with cancer are termed circulating tumor cells (CTCs). Presence of CTCs in the peripheral blood of patients with colorectal cancer has been reported to be associated with disease stage, poor prognosis, tumor progression, response to therapy, and drug resistance. Whether laparoscopic procedure enhances tumor spreading during operation remains unknown. Significantly less CTC detected during laparoscopic surgery than open surgery for colorectal cancer has been reported. In our previous experience, no significant elevation in CTC level was found in most patients during laparoscopic resection of colorectal cancer. We have shown that laparoscopic surgery had no significantly deleterious effect on CTCs in colorectal cancer patients. In this review, we aim at the impact of CTCs in patients with colorectal cancer undergoing laparoscopic surgery. The prognostic significance of CTCs in patients with colorectal cancer will also be addressed.

Abdominoperineal Resection without an Abdominal Incision for Rectal Cancer Has the Advantage of No Abdominal Wound Complication and Easier Stoma Care

Abdominoperineal resection has been used for years for the management of low rectal cancer. However, the abdominal incision is associated with many complications and causes interference of the stoma care. If the abdominal incision can be avoided, it would be beneficial to the patient. The aim of the study is to evaluate the possibility and safety of performing abdominoperineal resection and the oncology result without an abdominal incision. From September 2001 to May 2010, 40 patients with rectal malignancies received excision of the rectum, anus, and perineum through a perineal incision and a skin hole created for stomy. No harmonic scalpel or laser was used during surgery. No laparoscope or hand port was used in the procedure. There were 19 males and 21 females. Age ranged from 31 to 87 years old (average, 62.9 years). There were 39 adenocarcinomas and one malignant gastrointestinal stromal cell tumor. There was no operative mortality. Six patients had postoperative complications; three patients had intestinal obstructions; and one patient each had bleeding, urinary tract infection, and colostomy separation from the skin. The lymph nodes in the specimens ranged from 9 to 33 cm (average, 16.8 cm). The survival is similar to the traditional abdominoperineal resection. This limited experience suggests that an abdominal incision is not necessary for radical resection of the rectum, anus, and perineum in patients with low-lying rectal cancer. It also offers the patient easier care of stoma without interference of the abdominal incision.

A case of laparoscopic hepatectomy for recurrent hepatocellular carcinoma

Conventional hepatectomy is an effective way to treat hepatocellular carcinoma. However, it is invasive and stressful. The use of laparoscopy in hepatectomy, while technically demanding, reduces surgical invasiveness and stressfulness but still achieves complete resection with adequate margins. Compared with conventional hepatectomy, laparoscopic hepatectomy provides a better chance and situation for further surgery in the case of recurrence of hepatocellular carcinoma. Even aged patients can successfully endure repeated hepatectomy using laparoscopy, as shown in the present report. This report presents a case of repeated laparoscopic hepatectomy treating hepatocellular carcinoma and its recurrence in an aged patient having cirrhosis, a disease causing extra difficulty for performing laparoscopic hepatectomy. The report also describes techniques of the operation and displays characteristic results of laparoscopic hepatectomy such as smaller wounds, less blood loss, less pain, less scars and adhesion, shorter postoperative hospital stay, and faster recovery.

Intra-Abdominal Lesions Could be Missed by Inadequate Laparoscopy

Laparoscopic resection has become one of the choices for colectomy for various colon and rectal diseases in recent years. Despite some uncertainties of laparoscopic procedures, especially during cancer surgery, its popularity has forced surgeons to pursue the approach. One of the concerns is inadequate examination of the intra-abdominal organs with a laparoscope. This study is a retrospective analysis of a single surgeon's experience of the frequencies of unexpected findings during laparotomies. From July 1990 to November 2005, 2775 patients with various colorectal diseases receiving laparotomies by a single surgeon were analyzed. Among them, 2282 patients were operated for primary colorectal cancer. Excluded were patients who did not receive a formal laparotomy, who had a recent laparotomy, who had peritoneal and omental metastasis, and whose pathology did not attract attention for management. Exploration of the entire peritoneal cavity was performed for all cases in the series. There were 1423 males and 1352 females. Ages ranged from 12 to 94 years, averaging 62.6-years-old. Forty-six patients (1.7%) were found to have unexpected intra-abdominal lesions during laparotomies. Eleven patients were found to have synchronous colorectal cancers; five patients were found to have unexpected liver metastases; three patients each were found to have gastric cancers, stromal tumors of the small bowel, and ectopic pancreas; two patients each were found to have gastric leiomyosarcomas, pancreatic cancers, mucoceles of the appendix, ulcers of the small intestine, bleeding Meckel's diverticula, pancreatitis, and perforations of the ileum; one patient each was found to have gall bladder cancer, malignant carcinoid tumor, pheochromocytoma, diverticulitis of the jejunum, diverticulitis of the colon, duplication of the colon, and aortic aneurysm larger than 6 cm. Forty-one of the lesions were likely to be missed by laparoscope. This experience suggests that incomplete laparotomies might miss various pathologies. Laparoscopy is not a complete form of laparotomy because of loss of tactile sensation. Laparoscopy might result in an inadequate or inappropriate management due to misdiagnosis.

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.

Feasibility of colectomy with mini-incision

BACKGROUND

Laparoscopic resection has been advocated as a method of colectomy for various colon and rectal disease. One advantage claimed by laparoscopy is its smaller incision size. The aim of the present study is to evaluate whether mini-incision is feasible along with the advantage of adequate exploration of the peritoneal cavity.

METHODS

From December 2000 to November 2003, 316 patients with various colorectal diseases receiving colectomies through a skin incision less than 7 cm were analyzed. All of the colectomies were performed by a single surgeon. Exploration of the entire peritoneal cavity was possible for all the cases. There were 153 men and 163 women. Ages ranged from 19 to 90 years, averaging 62.4 years. Two hundred ninety-five patients were operated on for carcinoma of the colon or rectum; 4 had operations for villous tumors with severe dysplasia; 3 each for radiation enterocolitis and diverticulitis; 2 each for malignant stromal tumor and rectal prolapse; and 1 each for lymphoma, actinomycosis, volvulus, angiodysplasia, Crohn's disease, ulcerative colitis, and ovarian cancer with rectal invasion. There were 15 abdominoperineal resections, 97 low anterior resection, 49 anterior resections, 64 sigmoidectomies, 7 left hemicolectomies, 81 right hemicolectomies, 2 subtotal colectomies, and 1 restorative proctocolectomy. No Harmonic scalpel or laser was used during surgery. No hand-port or laparoscope was used in the series.

RESULTS

Five patients died of acute respiratory failure, 2 patients died of terminal cancer, and 1 patient died of hypoglycemia due to poor control of diabetes mellitus. Complications included 11 urinary tract infections, 8 intestinal obstructions, 6 anastomotic leakages, 6 wound infections, 5 respiratory failures, 5 pelvic bleedings, 2 pneumonias, 2 gastrointestinal bleedings, and 1 pancreatitis. Small incisions did not prolong operation time.

CONCLUSION

This experience suggests that the majority of colectomies can be accomplished by an incision of less than 7 cm, which is no larger than the incision size used in a laparoscope colectomy if multiple incisions made for trocars are added to the main incision length. The advantages of mini-incision include lower cost, faster completion of procedure, reduced bulkiness of equipment, and the possibility of exploring the entire peritoneal cavity by hand without loss of tactile sensation.

Connective tissue growth factor inhibits metastasis and acts as an independent prognostic marker in colorectal cancer

BACKGROUND & AIMS

Connective tissue growth factor (CTGF) has been shown to be implicated in tumor development and progression. The aim of this study was to investigate the role of CTGF in progression of colorectal cancer (CRC).

METHODS

Immunohistochemical staining of specimens from 119 patients with CRC was performed. Liposome-mediated transfection was used to introduce a CTGF expression vector into CRC cell lines. Transfectants were tested in invasive ability and experimental hepatic metastasis in BALB/c mice. Furthermore, a FOPflash/TOPflash reporter assay was performed to investigate CTGF on the beta-catenin/T-cell factor signaling pathway.

RESULTS

Patients with stage II and stage III CRC whose tumors displayed high CTGF expression had a significantly higher overall survival and a disease-free advantage over patients with CRC with low CTGF expression. Alterations in the CTGF level in CRC cell lines modulated their invasive ability with an inverse correlation. In addition, a reduction in the CTGF level of CT26 cells after stable transfection with antisense CTGF resulted in increased liver metastasis in BALB/c mice. The activity of the beta-catenin/T-cell factor signaling pathway and its downstream effector gene matrix metalloproteinase 7 in these CTGF-transfected cells was strongly attenuated. Blockage of matrix metalloproteinase 7 with its neutralizing antibodies inhibited increased invasiveness in antisense CTGF-transfected CT26 cells.

CONCLUSIONS

Our results implicate CTGF as a key regulator of CRC invasion and metastasis, and it appears to be a useful and better prognosis factor for patients with stage II and stage III CRC.

Impact of circulating free tumor cells in the peripheral blood of colorectal cancer patients during laparoscopic surgery

Despite widespread use of laparoscopic surgery for colorectal operations, its application for curative resection of colorectal cancer is still controversial. One of the major concerns is the impact of the laparoscopic procedure on dissemination of tumor cells. The main purpose of this study was to investigate the impact of laparoscopic surgery on circulating tumor cells in colorectal cancer patients. Quantitation of circulating free tumor cells (FTCs) was performed preoperatively, during the operation, and 14 days later by means of real-time quantitative reverse transcriptasepolymerase chain reaction (RT-PCR) targeting guanylyl cyclase C (GCC) mRNA in 42 colorectal cancer patients undergoing laparoscopic resections. Despite an increasing trend of FTC detection in patients with advancing stage, there is no significant difference in the preoperative FTC level by disease stage. No elevation in FTC level was found during the laparoscopic procedure in most patients compared with their preoperative FTC value. Patients with a persistently high FTC load [per nucleated blood cells (NBCs)] (> 10(2) FTCs/10(6) NBCs) 2 weeks postoperatively portends a poor prognosis regarding disease recurrence and tumor-related mortality when compared to those with an undetectable or low FTC load (< or = 10(2) FTCs/10(6) NBCs). We concluded that the laparoscopic procedure itself had no significantly deleterious effect on circulating FTCs and that the detection of FTCs by real-time qRT-PCR might be of clinical importance during the postoperative follow-up for colorectal cancer patients.

Impact of laparoscopic surgery on experimental hepatic metastases

BACKGROUND

Metastatic disease to the liver is one of the major factors determining outcome after colonic resection with curative intention. The influence of laparoscopic surgery on metastatic disease in the liver is still largely unknown.

METHODS

An intrasplenic tumour cell inoculation was performed in 30 WAG-Rij rats. After 7 days the rats were randomized into three operative groups: laparotomy (n = 10), laparoscopy with 7 mmHg carbon dioxide pneumoperitoneum (n = 10) and gasless laparoscopy (n = 10). A small bowel segmental resection was carried out in all rats. Some 21 days later the rats were evaluated for number and diameter of tumour nodules and cancer index score at eight different abdominal sites.

RESULTS

Hepatic tumour growth scored with the cancer index was significantly reduced in the gasless laparoscopy group compared with that in the carbon dioxide laparoscopy group (P = 0.04) and the laparotomy group (P = 0.02). Tumour growth at the port site and total tumour load were significantly reduced in the gasless group compared with the laparotomy group (P < or = 0.04).

CONCLUSION

Laparoscopy with carbon dioxide insufflation seems to stimulate the growth of dormant tumour cells into overt liver metastases. Gasless laparoscopy on the other hand may have a protective effect against metastatic disease in the liver. The promoting and inhibiting effects of laparoscopic procedures on growth of liver metastases need further evaluation.

Liver metastasis following pneumoperitoneum with different gases in a mouse model

BACKGROUND

The validity of using CO2 in laparoscopic tumor surgery has not yet been established. To address this question, we investigated the growth of liver metastases following insufflation with different gases in a mouse laparoscopy model.

METHODS

Male BALB/C mice inoculated intraportally with colon 26 cells were randomized to undergo pneumoperitoneum with CO2 (n = 16), helium (n = 16), argon (n = 16), or air (n = 17), or to act as controls without insufflation (n = 17).

RESULTS

The growth of cancer nodules on the liver 14 days after surgery was greater in mice following insufflation with CO2 (p < 0.01), helium (p < 0.01), argon (p = 0.01), and air (p = 0.07) than in control mice. No significant differences were found between the four insufflation groups in the growth of liver metastases.

CONCLUSION

These results suggest that insufflation plays an important role in the development of liver metastases but that the choice of gas may not affect their growth.

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.