Research and development of a new RF-assisted device for bloodless rapid transection of the liver: computational modeling and in vivo experiments.
BACKGROUND
Efficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously. In addition to the conventional clamp crushing or finger fracture methods other techniques based on radiofrequency (RF) currents have been extensively employed to reduce intraoperative blood loss. In this paper we present our broad research plan for a new RF-assisted device for bloodless, rapid resection of the liver.


METHODS
Our research plan includes computer modeling and in vivo studies. Computer modeling was based on the Finite Element Method (FEM) and allowed us to estimate the distribution of electrical power deposited in the tissue, along with assessing the effect of the characteristics of the device on the temperature profiles. Studies based on in vivo pig liver models provided a comparison of the performance of the new device with other techniques (saline-linked technology) currently employed in clinical practice. Finally, the plan includes a pilot clinical trial, in which both the new device and the accessory equipment are seen to comply with all safety requirements.


RESULTS
The FEM results showed a high electrical gradient around the tip of the blade, responsible for the maximal increase of temperature at that point, where temperature reached 100 degrees C in only 3.85 s. Other hot points with lower temperatures were located at the proximal edge of the device. Additional simulations with an electrically insulated blade produced more uniform and larger lesions (assessed as the 55 degrees C isotherm) than the electrically conducting blade. The in vivo study, in turn, showed greater transection speed (3 +/- 0 and 3 +/- 1 cm2/min for the new device in the open and laparoscopic approaches respectively) and also lower blood loss (70 +/- 74 and 26 +/- 34 mL) during transection of the liver, as compared to saline-linked technology (2 +/- 1 cm2/min with P = 0.002, and 527 +/- 273 mL with P = 0.001).


CONCLUSIONS
A new RF-assisted device for bloodless, rapid liver resection was designed, built and tested. The results demonstrate the potential advantages of this device over others currently employed.
Burdío
Fernando
F
Department of Surgery, Hospital del Mar, Barcelona, Spain. fburdio@hotmail.com
Berjano
Enrique J
EJ
Navarro
Ana
A
Burdío
José M
JM
Grande
Luis
L
Gonzalez
Ana
A
Cruz
Ignacio
I
Güemes
Antonio
A
Sousa
Ramón
R
Subirá
Jorge
J
Castiella
Tomás
T
Poves
Ignasi
I
Lequerica
Juan L
JL
D000818:Animals; D017076:Computer-Aided Design; D004564:Electrocoagulation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006498:Hepatectomy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D019106:Postoperative Hemorrhage / Q000209:etiology / Q000517:prevention & control; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013552:Swine