Wound metastases following laparoscopic and open surgery for abdominal cancer in a rat model

Abstract

The recent application of laparoscopic resection techniques to malignant disease has raised safety concerns due to metastasis to surgical access wounds. The significance and incidence of this problem are controversial. In the present study a rat model, in which an implanted tumour was lacerated, was used to investigate whether application of laparoscopic techniques for malignant abdominal disease leads to an increased risk of tumour dissemination and implantation within the peritoneal cavity, and abdominal wall wounds. Malignant cells were implanted into the abdominal wall of 42 rats, resulting 7 days later in the growth of a tumour measuring 20-25 mm in diameter. There were three control groups: no surgery (n = 6); blunt manipulation of the tumour laparoscopically (n = 6); and blunt manipulation of the tumour at laparotomy (n = 6). Twenty-four rats underwent surgical laceration of the tumour capsule at either laparoscopy (n = 12) or laparotomy (n = 12). All rats were killed 1 week later, and examined for macroscopic evidence of tumour metastasis. The abdominal surgical wounds were excised for independent microscopic examination by a histopathologist. Growth of the primary tumour was greater in rats that had an operation than in unoperated controls, and was greater after laparotomy. However, wound metastases were five times more likely after laparoscopic tumour laceration than after the same procedure through an open incision (ten of 12 rats versus two of 12, P = 0.0033). Wound metastases following laparoscopic tumour manipulation are an important and real problem, with significant implications for the application of laparoscopic techniques to excise malignant disease in humans.

The author replies

“…We have recently reported the results of a study on the impact of CO 2 and gasless laparoscopy on abdominal wall metastases in rats [4]. In accordance with the study by Watson and Mathew we found significantly greater port site metastases in rats having CO 2 laparoscopy compared to gasless laparoscopy [6]. Therefore, further study on gasless laparoscopy in digestive cancer is required.…”

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

“…Laparoscopy also has been proposed in the staging of advanced ovarian cancer 8 or for second look procedures. Potential deleterious effects of CO 2 pneumoperitoneum have been described recently 1,2 . However previous studies have focused on port-site metastasis and peritoneal cell seeding, whereas general effects have not been investigated as much.…”

Laparoscopic surgery for cancer patients

“…148,149 Several animal studies show that the effects of pneumoperitoneum, especially with carbon dioxide, lead to increased implantation of tumor cells in the abdominal wall. 12,150,151 Studies of rats undergoing laparoscopic surgery showed a threefold to fivefold increase in the incidence of metastases in the abdominal access wounds of those with pneumoperitoneum compared with those without pneumoperitoneum. 12,151 Some surgeons have proposed gasless laparoscopy to alleviate the theoretical concerns of pneumoperitoneum in cancer patients.…”

“…12,150,151 Studies of rats undergoing laparoscopic surgery showed a threefold to fivefold increase in the incidence of metastases in the abdominal access wounds of those with pneumoperitoneum compared with those without pneumoperitoneum. 12,151 Some surgeons have proposed gasless laparoscopy to alleviate the theoretical concerns of pneumoperitoneum in cancer patients. 152,153 An added benefit of gasless laparoscopy is that conventional instruments can be used through the small incisions, potentially decreasing operative time.…”