Energy Sources for Laparoscopic Surgery

Apart from monopolar and bipolar electrocautery, a variety of different energy sources have been introduced for tissue cutting and/or hemostasis that can be used laparoscop-ically. These include ultrasonic energy, LigaSure,c hydrodissector, and argon beam coagulator.

Ultrasonic energy has been successfully used for tissue dissection and hemostasis during laparoscopic procedures (4). The commercially available ultrasonic generators provide a variety of effecter tips (5 and 10 mm) for laparoscopic surgery. With ultrasonic cValleylab, Boulder, CO.

TABLE 1 ■ Efficacy of Various Energy Sources in Laparoscopic Surgery

Energy source

Vessel sizea

Collateral spread (mm)

LigaSure

Artery: 6 mm

1-3

Vein: 12 mm

Ultrasonic

3 mm

0-1

Bipolar

Unreliable

1-6

aMaximum diameter of the vessel that was reliably occluded. Source: From Ref. 6.

Surgical clips and staplers are predominantly used for securing medium and large caliber vessels during laparoscopic surgery.

FIGURE 7 ■ Titanium surgical clip.

FIGURE8 ■ Locking plastic surgical clip.

energy, tissue cutting and coagulation is achieved at lower temperatures (50-100°C) as compared to electrocautery. This reduces the lateral scatter, charring, and smoke production. Disadvantages of the ultrasound dissection include equipment cost and decreased speed of dissection compared to conventional electrocautery.

The LigaSure system is designed for providing hemostatic sealing of blood vessels up to 7 mm in diameter (5). Specific to urologic surgery, the LigaSure has been used for securing blood vessels, such as the lumbar, gonadal, and adrenal vein in select cases in lieu of surgical clips. The LigaSure technology combines compression pressure and thermal energy to cause denaturation of the vessel wall collagen and secure vessel occlusion. A feedback mechanism regulates the amount of energy to be delivered and gives an audible signal to the surgeon when effective vessel occlusion has been achieved. The LigaSure system is thought to produce less charring and tissue sticking compared to conventional bipolar coagulators. Landman et al. compared the relative efficacy of ultrasonic energy versus bipolar cautery versus LigaSure in the laboratory and found that LigaSure had the best hemostatic efficacy and ultrasonic shears had the least collateral scatter (Table 1) (6).

Argon beam coagulation provides excellent superficial hemostasis for superficial bleeding surfaces (7). It is particularly helpful for controlling mild oozing from parenchymal bleeding surfaces, such as liver, spleen, kidney, and muscle. Additionally, the argon beam coagulator does not produce any forward scatter. The use of the argon beam coagulator during laparoscopic surgery may cause a precipitous rise in intraabdominal pressure; therefore, one of the trocars should be continuously vented during its use.

0 0

Post a comment