Experimental study on heat production by a 23.5-kHz ultrasonically activated device for endoscopic surgery

Abstract

An experimental study was carried out to evaluate heat production by an ultrasonically activated device (USAD) using an animal model. In an anesthetized living pig, the gastroepiploic and mesenteric vessels were coagulated and cut by an USAD at a power level of 70% (n = 8) or 100% (n = 8). During the division, the time-discrete temperature change on the surface of the animal tissue adjacent to the blade was measured by thermography. To compare the USAD with conventional electrocautery (EC), a full-thickness incision of the gastric wall was performed by each device, and the temperature change was measured. With the USAD, the temperature increased gradually and remained below 150 degrees C during the entire activating time at both power levels. By contrast, with EC at 30 W, the temperature increased rapidly and exceeded 350 degrees C within only a few seconds. The area above 60 degrees C reached a final width of 10 mm for the USAD, as compared with 22 mm for EC. Microscopically, thermal alterations such as carbonization and vaporization were much more severe and extensive in the adjacent tissue when using EC rather than the USAD. With the USAD, heat production is much slower and more limited than with conventional EC; thus, the USAD causes fewer thermal alterations in adjacent tissue. USAD should be preferred for tissue coagulation and cutting during endscopic surgery.

Is laparoscopic appendectomy in children associated with an uncommon postoperative complication?

“…Real-time thermography studies have shown that the level of collateral heat spread was higher than that observed in histological studies [3]. It was also demonstrated that the ultrasonic scalpel induced a lateral spread of heat into contiguous tissue conducting to a temperature higher than 60°C, up to 10 mm around the electrode [12]. The laparoscopic ultrasonic coagulating shears was found to provoke a mean lateral thermal injury of 1.6 mm [8], and the heat spread with standard bipolar electrocautery can be as large as 22 mm [12].…”

Hybrid NOTES transvaginal cholecystectomy: operative and long-term results after 18 cases

“…Although there is no definite data in the literature, nevertheless there are clear evidences that ultrasonic energy decreases lateral thermal damage and creates lower temperatures than electrosurgery with potentially lower risk of inadvertent injuries to surrounding structures. Besides, the necrotic tissue associated with electric surgical char may compromise healing, whilst carbonisation in surrounding tissues with ultrasonic dissection is minimal compared to both unipolar and bipolar coagulation [22][23][24][25][26]. In one randomised study, the perforation rate during laparoscopic cholecystectomy was significantly lower with US than with electrocautery [27].…”

Radiofrequency versus ultrasonic energy in laparoscopic colorectal surgery: a metaanalysis of operative time and blood loss

“…However, the assumption that the described devices significantly reduce the risk of collateral thermal injury was disproved by animal experimentation, which confirmed the Graphic 2 LigaSure versus ultracision energy: operating time generation of very high temperatures at the instrument tip and thermal damage [11,[27][28][29]. Among the alternative energy sources, an innovation in tissue-selective separation/dissection using water jet could be the Erbejet 2 (ERBE USA, Inc., Georgia), which uses precise and gentle pressure rather than intense heat.…”