Optimizing bipolar electrocoagulation for endoscopic hemostasis: assessment of factors influencing energy delivery and coagulation.

BACKGROUND

Few data inform decisions on the optimal bipolar electrocoagulation (BPEC) technique.

OBJECTIVES

To assess how technical factors influence energy delivery and coagulation.

DESIGN

Prospective, randomized study in experimental models: meat, live pig mesenteric arteries.

INTERVENTIONS

Standard and prototype BPEC probes were applied at varying durations (2, 10, and 20 seconds), application forces (5, 75, and 150 g), and watt settings (10, 15, and 20 W). BPEC devices were applied to arteries with 40 g versus no additional force.

MAIN OUTCOME MEASUREMENTS

For the meat model: energy delivered, impedance, coagulation and cavitation depth, and coagulation surface area. For the mesenteric arteries: hemostasis.

RESULTS

The energy delivered increased with duration and force (P < .001) but not with the watt setting. Impedance rose rapidly at higher watt settings (>300 ohms within approximately 5 seconds at 20 W and approximately 10 seconds at 15 W), with a coincident drop in power. Coagulation depth and surface area correlated with energy delivered (r = 0.70-0.97). Only duration was associated with the coagulation depth (P < .001); cavitation (which occurred with a standard BPEC probe) plus coagulation depth was also associated with application force (P < .001). Hemostasis of the mesenteric arteries was achieved only with 40 g of force.

LIMITATIONS

The accuracy of these models in predicting clinical results is uncertain.

CONCLUSIONS

Increasing BPEC duration increased the energy delivered and the coagulation, whereas increasing the watt setting did not because of a rapid rise in impedance. Optimal BPEC technique included a lower watt setting (eg, 15 W), a longer duration (eg, approximately 10-12 seconds), and tamponade of the bleeding site.