Separating Cords during laparoscopic surgery could minimize injury

Last Updated: 2015-02-11

By Scott Baltic

NEW YORK (Reuters Health) - Separating the laparoscopic camera cord from the monopolar "Bovie" cord - as opposed to bundling those cords parallel to each other - cuts the number of unintended thermal injuries at the camera trocar incision by nearly half, according to a report published online January 23 in Annals of Surgery.

The prospective, blinded, randomized controlled study encompassed 84 patients undergoing elective laparoscopic cholecystectomy.

The practice of placing the two cords parallel and in close proximity inadvertently transfers energy, through a phenomenon called antenna coupling, from the monopolar active electrode and its wire to the laparoscopic camera cord.

The "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," wrote the authors, who are affiliated with the University of Colorado Anschutz Medical Campus and with Covidien Surgical Solutions Group.

However, the report also noted three important points. The first is that the thermal injuries at the camera trocar incisions were only a surrogate endpoint for the most definitive endpoint, that is, thermal injury to the bowel that leads to bleeding, perforation, or another clinically significant outcome.

Second, such life-threatening bowel injuries are quite rare, having been estimated by a 1994 report cited in the current paper to be about 1 in 1,000.

Third, the authors wrote, "the thermal injuries found by histology in this study are likely not clinically significant and may reflect heat effect rather than a thermal burn . . . Our intention is not to state the heat effect documented is clinically deleterious."

"Although the results are not clinically significant, the findings should lead us to separate the cords if not impossible in the OR configuration," Dr. Nathaniel Soper, Northwestern Medicine chief of surgery and director of minimally invasive surgery at Northwestern Memorial Hospital in Chicago, told Reuters Health in an e-mail.

"Although these skin findings are not significant, there have been rare instances of thermal injury to the intestine that have not otherwise been explained and may be due to this effect," he said.

The study enrolled 84 patients between September 2012 and August 2013. The average age was 44 ± 17 years, and 82% (69) of the patients were female.

Half were randomized to the control group, whose surgeries were performed with bundled active-electrode and camera cords. The other half were randomized to the experimental group, in which surgeries were performed with the two cords separated.

The latter group experienced thermal injury at the skin adjacent to the camera/telescope (umbilical) trocar in 31% of instances, versus 57% in the control group (p=0.027).

Covidien Surgical Solutions performed the histology for the study, and two of the eight authors are Covidien employees.

SOURCE: http://bit.ly/1DhMXxN

Ann Surg 2015.