Energy sources

Monopolar electrosurgical instruments have been used during lap­aroscopic procedures since the first half of the twentieth century (55), with the addition of bipolar instruments used for laparoscopic steril­ization in 1973 (56).

Adding different effects such as pressure in addition to electro­surgery and ultrasonic has led to new-generation hybrid energy sources designed to provide optimized tissue effects (especially for vessel sealing) with improved safety profiles compared to conven­tional electrosurgery (59). These instruments are said to be more time efficient by decreasing ‘instrument traffic' and to decrease en­ergy source costs by reducing the overall number of surgical instru­ments (59, 60).

Substantial advantages of using monopolar electrosurgery at laparoscopy are simplicity, availability, and wide range of available tissue effects (55, 59-61). Complex instrumentation with specialist electrosurgical generators is not essential and costs may be minim­ized with simple instruments. Knowledge of the possibility of stray current injuries that might occur and steps that can be implemented to limit the risk such as the use of active electrode monitoring are es­sential when utilizing any monopolar electrosurgical instrument at laparoscopy (60, 62-65). All laparoscopic energy sources ultimately generate thermal energy to generate their respective tissue effects. Irrespective of the fact that bipolar, ultrasonic, and laser technolo­gies are not subject to the risk of electrical stray current injuries as­sociated with monopolar electrosurgery, the heat generated by all these modalities has the potential to cause lateral thermal spread injuries (59).

Surgical comparative studies on laparoscopic energy sources often focus on clinical outcomes such as operating time, blood loss, postoperative pain, and complications with new-generation energy sources (i.e. ultrasonic and advanced bipolar devices) reportedly superior to conventional bipolar and monopolar electro surgery (59). These statistical differences may be of limited clinical value since they may report a significant decrease in blood loss of tens of millilitres—a finding that will have no clinical consequence.

Laboratory-based comparative studies on laparoscopic energy sources have most commonly focused on parameters such as vessel burst pressure, vessel seal time, lateral thermal spread, and smoke plume generation (59, 60). All modern vessel sealing energy sources yield burst pressures in the supraphysiological range (i.e. above mean arterial pressure), therefore any differences observed in burst pressures for individual are probably not clinically significant. The data for lateral thermal spread are inconsistent with no superiority for any particular energy source. Comparative studies on smoke or vapour generation by energy sources generally shows that while all energy sources create a smoke plume, the order of energy sources that produce least to most smoke production is ultrasonic, advanced bipolar, conventional bipolar, and monopolar.

The cost of energy sources may determine the choice of device available and used with both direct and indirect costs to consider (66). Indirect costs include the costs related to time off work, post­discharge care, loss of productivity, etc. Apart the upfront capital cost of the actual device (and generator unit), direct costs include also include ongoing costs such as sterilization of reusable devices, associated disposable equipment, and servicing. In addition, re­admissions due to complications are direct costs. The choice of energy source will depend on consideration of all these factors, with no single energy source appropriate for all laparoscopic pro­cedures. Surgeons will often use a range of instruments depending on their mentors' teaching, their own personal experience, the type of procedure, and the likelihood of distorted anatomy and adhesions (60).