Inter- and intraindividual variabilities of perforation forces of human and pig bowel tissue.
BACKGROUND
A laparoscopic bowel grasper should be suitable for safely grasping the bowel in a wide variety of patients. Therefore, the inter- and intraindividual variabilities in the strength of bowel tissue to resist perforation force should be analyzed.


METHODS
The large and small bowels of pigs ( n = 14) and the human small bowel ( n = 7) were clamped between two hemispheres 1.5 mm in diameter. The pinch force was increased until the tissue was perforated.


RESULTS
The perforation force for the pig large bowel was higher than for the small bowel (13.5 +/- 3.7 vs 11.0 +/- 2.5 N; p = 0.014). No difference was found between the human and pig small bowel (10.3 +/- 2.9 vs 11.0 +/- 2.5 N). The intercoefficient of variation varied between 22% and 28%, and the intracoefficient of variation varied between 14% and 18%.


CONCLUSIONS
The strength of the pig bowel is approximately comparable to the strength of the human bowel, and, therefore, testing of graspers on pig bowel is justified. However, due to the large interindividual variation, large safety margins should be taken into account.
Man-Machine Systems Group, Faculty of Mechanical Engineering and Marine Technology, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands. e.a.m.heijnsdijk@wbmt.tudelft.nl
E A M
EA
Heijnsdijk
M
M
van der Voort
H
H
de Visser
J
J
Dankelman
D J
DJ
Gouma
D000328:Adult; D000368:Aged; D000818:Animals; D002432:Cecum / Q000502:physiology*; D014644:Genetic Variation; D006801:Humans; D007416:Intestinal Perforation / Q000209:etiology* / Q000517:prevention & control; D007421:Intestine, Small / Q000502:physiology*; D007431:Intraoperative Complications / Q000209:etiology* / Q000517:prevention & control; D010535:Laparoscopy; D008875:Middle Aged; D023421:Models, Animal; D011312:Pressure; D012449:Safety; D013045:Species Specificity; D013314:Stress, Mechanical; D013525:Surgical Instruments; D013552:Swine / Q000033:anatomy & histology* / Q000502:physiology