G Champault N Taffinder, M Ziol, H Riskalla, JMC Catheline. Cells are present in the smoke created during laparoscopic surgery. British Journal of Surgery 1997; 84:993-995.

Following concern over reports of metastatic spread of malignant disease after laparoscopic surgery, the authors examined the smoke generated by electrocoagulation for the presence of viable cells. This results indicated an area of concern for patients and for operating staff.

Nine patients undergoing laparoscopic surgery involving electrocoagulation were included in the study. A high-flow insufflator was used to provide 120-590 litres (mean 285 L) carbon dioxide to maintain the pneumoperitoneum. Gas was allowed to leak during the procedure through an "exhaust chimney" consisting of a plastic cannula attached to a trocar. A Pall insufflation gas filter (IGF1) was attached to the chimney to filter the exhaust. After the procedure the filters and tube were rinsed with phosphate-buffered saline, which was centrifuged. The collected solid material was stained or tested using standard avidin-biotin-peroxidase complex methodology for creatine kinase, anti-human leukocyte common antigen and Antivimentin. Three filters were also examined using electron microscopy.

Six of the nine samples of filter-washing contained cells. The three negative samples were from short procedures, two laparoscopc cholecystectomies and one liver biopsy, involving very little coagulation and smoke formation. Immunohistochemistry of positive samples showed the presence of mesothelial cells, the yield apparently, related to the length and difficulty of procedure and amount of coagulation used (not quantified). Electron microscopy of three filters showed debris and cells stuck to the "patient side" of the filter. Morphologically, these cells appeared to be mesothelial and blood cells. No cells were seen on the "downstream side" of the filters. All patient recovered and no cutaneous metastatic disease has been reported so far for the two patients with malignant disease.

The authors conclude that free cells exist in aerosol form in the pneumoperitoneum and can be present in the exhaust. These cells appeared to be whole and took up cytochemical stains. Metastases around the trocar sites may be caused by these cells. The presence of viable cells in laser smoke has implications for operating staff. Other studies looking at open surgery have found viable viral material in laser smoke and there have been anecdotal reports of verrucae developing in the anterior nares of laser operators. In the case of laparoscopic procedures, the smoke is pressurised, concentrated and moist and may be forced out of the pneumoperitoneum in a concentrated jet.