Experimental study of the material composition of laparoscopic ports on tumour cell adherence

Laparoscopic resection of intra-abdominal malignancies has yet to be widely adopted, partly because of concerns over the possible increase in the rate of port-site metastasis. The aetiology of these is unclear, but the laparoscopic instrumentation used may influence the deposition of tumour cells at the port sites during operation. An in vitro model to examine tumour cell adherence to laparoscopic ports and to port sites was developed to examine this hypothesis.

A pilot study (study 1) was performed in which six smooth plastic, six ribbed plastic and six metal ports were introduced through the shaved abdominal wall of a cadaveric sheep and suspended in a water-bath containing radiolabelled LIM 1215 human colonic cancer cells for 30 min. Radioactivity on both ports and port sites was measured and the number of cells adherent to each structure was calculated. The study was expanded to include a further 36 smooth plastic ports and 36 metal ports (study 2).

In study 1 metal ports were found to have significantly more adherent cells than plastic ports (P = 0.004), as did ribbed ports when compared with smooth ports (P < 0.05). In study 2 increased numbers of cells were again detected on metal ports (P < 0.001) when compared with plastic ports. Significantly greater numbers of cells were also detected on the sites through which metal ports had passed than on sites through which plastic ports had passed (P = 0.03).

In this model, the use of metal ports as opposed to plastic ports resulted in increased deposition of tumour cells on both ports and port sites.