An experimental study on the utility of a 3-mm ultrasonically activated trocar system.
OBJECTIVE
A prototype of a 3-mm ultrasonically activated trocar system supplied by Olympus Corporation was evaluated experimentally in terms of its utility and safety.


METHODS
Three piglets with an average weight of 12 kg were used. A pneumoperitoneum was created by Hasson's technique. Eleven punctures were made with a disposable conical 3-mm trocar (CT), 9 punctures with a 3-mm radially expanding trocar (ET), and 13 punctures with a 3-mm ultrasonically activated trocar (UT) under laparoscopic control. The authors recorded the time for abdominal penetration, the severity of the peritoneal tenting, the presence of elevated abdominal pressure of 5 mm Hg or more at the penetration, and the maximal force applied to the trocar to remove from the abdominal wall.


RESULTS
The average times for penetration were 11.8, 9.4, and 3.8 seconds with CT, ET, and UT, respectively (P < .05, CT v. UT, ET v. UT). The average maximal forces at the trocar removal were 10.52, 21.17, and 21.24 N with CT, ET, and UT, respectively (P < .05, CT v. ET, CT v. UT). Elevation of abdominal pressure of 5 mm Hg or more was recorded in CT and ET but not in UT. Peritoneal tenting was the most severe in ET and minimal in UT. No complication related to the UT system was found.


CONCLUSIONS
The 3-mm UT is a simple and safe device and is expected to become commercially available.
Nio
Masaki
M
Department of Surgery, Miyagi Children's Hospital, Sendai 989-3126, Japan.
Ishii
Tomohiro
T
Amae
Shintaro
S
Wada
Motoshi
M
Nishi
Kotaro
K
Hayashi
Yutaka
Y
D000818:Animals; D004867:Equipment Design; D020706:Laparoscopes; D013525:Surgical Instruments; D013552:Swine; D014465:Ultrasonics