Comparison of coagulation modalities in surgery.

The increase in laparoscopic surgery has resulted in an increased need for a safe and reliable method of obtaining minimally invasive operative hemostasis. Because the traditional "open" methods of controlling bleeding (pressure, tying, and suture ligating) are not as easily applied in the laparoscopic arena, a heavy reliance on forms of tissue and vessel coagulation is necessary. To better assess these forms, we compare monopolar, bipolar, and ultrasound energy, in addition to laser energy used in a novel application. In the first part, 20 rabbit mesenteric arteries that measured 1 to 1.5 mm in diameter were coagulated using each of the technologies. We measured the time to coagulation, the efficacy of hemostasis, lateral tissue damage, and local tissue temperature of the vessels when exposed. Part 2 consisted of a survival study using 12 New Zealand white rabbits. In each of these two groups splenectomies were performed. A laser-heated forceps was compared to a monopolar electrosurgery device for the speed of the operation, blood loss, and adhesion grade at necrosectomy. In addition, the speed to cauterization of the iliac vessels and the amount of tissue damage was measured. These vessels were also examined for the extent of microscopic damage. Bipolar electrosurgery was much slower than the other modalities, while monopolar electrosurgery caused significantly more tissue damage and elevation in lateral tissue temperature. The ultrasound technology and the laser-heated forceps were equally safe and efficacious instruments. There was no significant difference in the ability of the laser-heated forceps or the monopolar cautery to perform the splenectomy safely. However, the forceps cauterized the iliac vessels faster and with less lateral thermal injury than the ultrasound device. Although each instrument has its place in the surgical armamentarium, the ultrasound technology appears to be the safest and most efficacious commercially available device for obtaining hemostasis. The laser, as it is applied in this setting, was also highly effective, but still a prototype device.