Separating the Laparoscopic Camera Cord From the Monopolar "Bovie" Cord Reduces Unintended Thermal Injury From Antenna Coupling: A Randomized Controlled Trial.
OBJECTIVE
The monopolar "Bovie" is used in virtually every laparoscopic operation. The active electrode and its cord emit radiofrequency energy that couples (or transfers) to nearby conductive material without direct contact. This phenomenon is increased when the active electrode cord is oriented parallel to another wire/cord. The parallel orientation of the "Bovie" and laparoscopic camera cords cause transfer of energy to the camera cord resulting in cutaneous burns at the camera trocar incision. We hypothesized that separating the active electrode/camera cords would reduce thermal injury occurring at the camera trocar incision in comparison to parallel oriented active electrode/camera cords.


METHODS
In this prospective, blinded, randomized controlled trial, patients undergoing standardized laparoscopic cholecystectomy were randomized to separated active electrode/camera cords or parallel oriented active electrode/camera cords. The primary outcome variable was thermal injury determined by histology from skin biopsied at the camera trocar incision.


RESULTS
Eighty-four patients participated. Baseline demographics were similar in the groups for age, sex, preoperative diagnosis, operative time, and blood loss. Thermal injury at the camera trocar incision was lower in the separated versus parallel group (31% vs 57%; P = 0.027).


CONCLUSIONS
Separation of the laparoscopic camera cord from the active electrode cord decreases thermal injury from antenna coupling at the camera trocar incision in comparison to the parallel orientation of these cords. Therefore, parallel orientation of these cords (an arrangement promoted by integrated operating rooms) should be abandoned. The findings of this study should influence the operating room setup for all laparoscopic cases.
*Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO †Covidien Surgical Solutions Group, Boulder, CO.
Thomas N
TN
Robinson
Edward L
EL
Jones
Christina L
CL
Dunn
Bruce
B
Dunne
Elizabeth
E
Johnson
Nicole T
NT
Townsend
Alessandro
A
Paniccia
Greg V
GV
Stiegmann
D000328:Adult; D002056:Burns / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects / Q000295:instrumentation*; D004564:Electrocoagulation / Q000009:adverse effects / Q000295:instrumentation*; D004566:Electrodes / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D012867:Skin / Q000473:pathology*; D013525:Surgical Instruments / Q000009:adverse effects