Functional luminal imaging probe geometric and histomorphologic analysis of abdominal wall wound induced by different trocars in pigs.

BACKGROUND: This study aimed to investigate wound geometry and tissue damage caused by several different trocar types using a quantitative functional luminal imaging probe (FLIP) geometric profile and histomorphologic analysis. METHODS: Four pigs were used in this study. After general anesthesia, six different trocars were randomly inserted at preselected locations in the porcine abdominal wall. The hydration status of the animals was monitored and maintained. A bag mounted on a FLIP was used to profile the geometry of the trocar holes during distension. After the FLIP study, the abdominal wall surrounding the trocar holes was harvested. The tissue was fixed in neutral 10% buffered formalin solution for more than 24 h. The samples contained control tissue (undamaged) and test tissue (damaged) through the entire rectangular tissue block. Approximately four to seven slides were cut parallel to the surface from each sample. Each slide was photographed, and the morphometry of the hole and damaged areas were measured and displayed three-dimensionally. The histologic sections were analyzed with regard to acute damage, bleeding, and acute inflammation of the skin, muscle, and fascia. RESULTS: The FLIP study demonstrated differences between the six trocars. These were mainly due to differences between the Versaport Plus V2 bladed trocar with the smooth cannula, the Applied Medical Separator nonbladed access system with threaded cannula, and the VersaStep Plus trocar. The morphometry data showed the smallest hole and damage areas for the Versaport Plus V2 bladed trocar with the smooth cannula. The damaged area divided by the trocar hole area was smallest for the VersaStep plus trocar and the Ethicon Endopath bladed trocar with a stability cannula (p < 0.05). The histologic analysis showed that the VersaStep Plus trocar and the Ethicon Endopath bladed trocar with a stability cannula gave the least bleeding and inflammation (p < 0.05). CONCLUSION: An agreement was found between the geometric data obtained by FLIP, the morphometric analysis, and the histology.

Analysis of abdominal wounds made by surgical trocars using functional luminal imaging probe (FLIP) technology.

The aim was to use a novel functional luminal imaging probe for evaluation of wound defects and tissue damage resulting from the use of trocars. Following general anesthesia of 4 adult pigs, 6 different trocars were randomly inserted at preselected locations in the porcine abdominal wall. The functional luminal imaging probe was used to profile the trocar holes during bag distension from 8 axial cross-sectional area measurements. The cross-sectional areas and pressure in the bag were recorded and exported to Matlab for analysis and data display. Geometric profiles were generated, and the minimum cross-sectional area and hole length (abdominal wall thickness) were used as endpoints. Successful distensions were made in all cases. The slope of the contours increased away from the narrowest point of the hole. The slope increased more rapidly toward the inner abdominal wall than toward the outer wall. The slope of the linear trend lines for the cross-sectional area-pressure relation represents the compliance at the narrowest point in the wall. The hole length (abdominal wall thickness) could be obtained at different cross-sectional area cutoff points. A cutoff point of 300 mm(2) gave good results when compared to the length of the hole measured after the tissue was excised. This technique represents a new and straightforward way to evaluate the effects of trocars on the abdominal wall. It may also prove useful in comparing techniques and technology from different manufacturers.