**3. What is the safest laparoscopic access method?**

Complications of laparoscopic access may not be recognized at the time of injury. In order to minimize as much as possible the risk of these complications, several entry methods have been developed. The most commonly described techniques include the non-insufflated open method, the direct trocar method, the closed-entry method of inserting a Veress needle blindly for CO2 insufflation and the optical entry methods [1–5].

What is the preferred laparoscopic entry technique? This has been a controversial issue for more than two decades and subject to many studies and much debate. The issue has its roots in the attempt to identify the technique least associated with complications. Indeed, 50% of minor and major complications are related to the initial entry into the abdomen during the primary trocar insertion. The Veress needle method was originally thought that it would cause less major injury to intra-abdominal structures because of the smaller diameter of the instrument.

A Cochrane review of laparoscopic entry techniques [1] failed to demonstrate any evidence of the benefit, of one technique over another, in terms of safety and in preventing visceral or vascular injury [1]. On the other hand, a more recent review by Raimondo et al. showed that direct trocar insertion is associated with less complications than the use of Veress needle and open methods for laparoscopic access [3]. The direct trocar method is especially associated with a much lower risk of injury to the greater omentum, failed access, and extraperitoneal insufflation when compared to the Veress needle method, and of injury to the bowel and infection at the trocar site when compared to the open method. In addition, using the Veress needle method is associated with a much higher risk of injury to the omentum, extraperitoneal insufflation, and late risk of incisional hernia when compared to the open method.

The direct trocar method seems to be the safest technique, and the use of the Veress needle is the least safe. Given that the Veress needle is removed before the primary trocar is placed, an omental needle injury can remain undetected for a long time. With extraperitoneal insufflation caused by the inappropriate placement of the Veress needle, in addition to subcutaneous and omental emphysema, a carbon dioxide embolism can also occur. The increased risk of failed access may seem to indicate a technique that is more difficult to learn and to be correctly implemented. In comparison with the Veress needle technique, using the direct trocar method reduces the number of blind steps from three to one. Direct access with a trocar might therefore reduce the complication rates for less experienced surgeons.

The analysis by Raimondo et al. indicates a preference of the direct trocar method over the open method due to a decreased risk of injury to the viscera and infection at the site of the trocar. In fact, the open method requires sharp instruments, while the direct trocar method consists of the insertion of a blunt plastic trocar. In addition, the direct trocar method may use an optical trocar for quick visual identification of the bowel during the insertion of the trocar compared to the open method. The optical trocar system, such as Visiport, may therefore represent an advantage over traditional trocars, but this advantage has not been fully explored. Optical trocar systems also have the advantage of minimizing the size of the entry wound and reducing the force necessary for insertion. However, surgeons using this technique should exert a degree of caution since optical trocars may also be associated with significant injuries despite having the ability to visualize tissue layers during insertion. The increased risk of a surgical site infection with the open method might be resulting from the longer length of the procedure and the need to handle more surgical tools, which may facilitate the contamination of the surgical field.

These conclusions may be affected by the limitations of the included studies. Some of the studies are of poor quality, with inappropriate statistical power to demonstrate a difference between the various laparoscopic access techniques especially when the incidence of major complications is so low.

Current international guidelines do not recommend one entry method over the others, with the choice being based on the preferences of the surgeon and the local availability of resources. In this scenario, Raimondo et al. state, "providing
