Laparoscopy and tumour growth : a clinical and experimental study

Sammanfattning: Background and aims: Laparoscopic technique was quickly adopted in general surgery because of less pain, quicker recovery and shorter hospital stay. In the 1990´s several reports on port site metastases restrained the enthusiasm to use laparoscopic surgery in malignant diseases. The numerous reports on port site metastases initiated a debate whether laparoscopic surgery would increase the risk of tumour spread and growth. Personal experience of two patients who devloped port site metastases from an incidental gall bladder cancer (GBC) after laparoscopic cholecystectomy (LC), encouraged us to study the incidence of wound metastases from GBC after laparoscopic and open cholecystectomy (OC). Experimentally we examined whether pneumoperitoneum would increase the risk of tumour development. Several studies had demonstrated that minimally invasive procedures exert a less negative influence on the immune system and may have beneficial effects for cancer patients. We wanted to compare the long term survival after OC and LC and if the occurence of port site metastases had any impact on survival. Material and methods: A questionnaire was sent out to all major hospitals in Sweden requesting information obout the number of port site metastases encountered 1991-94. Data on all pateints with verfied GBC were obtained from the Swedish Oncological Centres. Data on all patients with GBC registered with surgical codes for cholecystectomy were collected from the National Board of Health and Welfare (EpC). The patient files were scrutinized and long term survival data was achieved (EpC). In the first experiment on Wistar Fu rats, adenocarcinoma cells were injected intraperitoneally in animals insufflated with air, CO2 and not insufflated controls. In the following studies, rats were similarly insufflated with air,CO2 and compared to not insufflated controls. Laser Doppler blood flow in the abdominal wall was concomitantly measured. To study the effect of reduced blood flow, one rectus muscle was clamped and the other not and laser Doppler Blood flow was measured in both rectus muscles. Adenocarcinoma cells were injected into the rectus muscles in all animals at the induction of pneumoperitoneum/clamping. Results: 14 of 55 patients developed wound metastases from GBC after LC and 12 of 187 after OC. Gallbladder perforation was overrepresented in patients with wound metastases. Improved survival was noted after LC in patients with T3 tumours. Experimentally, air and CO2 equally increased intraperitoneal tumour development, Insufflation with air,CO2 and clamping decreased blood flow in the abdominal wall and increased tumour growth at the same site. Conclusion: Despite a high rate of wound metastases, LC does not seem to worsen the prognosis of GBC and may even have a positive effect on survival. Perforation of the malignant gallbladder seems to be associated with an increased risk of metastatic formation. In the experimental setting, pneumoperitoneum seems to increase tumour development. Other features of laparoscopic surgery such as decreased blood flow in the abdominal wall may contribute to increased risk of tumour progress.