Entry techniques

Entry complications

More than half of major complications associated with laparoscopy occur during entry into the abdomen. While most of these compli­cations are rare, when they do occur, vascular injury and bowel in­juries are the most serious and life-threatening and may result in death, with urinary tract injury occurring less commonly and usu­ally with less associated morbidity.

The reported incidence of vascular injury during laparoscopy ranges from 0.02% to 0.5% with up to a 15% mortality rate (30, 31). The distal aorta and the right common iliac artery are the vessels usually involved due to the anatomical relationship to the umbilicus and left-sided approach for the majority of right-dominant handed surgeons. The inferior epigastric vessels may be injured during placement of secondary ports and visualization both during place­ment and removal of secondary ports is recommended to reduce this risk (31).

The incidence of bowel injury in laparoscopy is 0.04-0.5% with the small bowel accounting for 58% of injuries, the colon 32%, and the stomach 8% of injuries (30-32). (30). Between one-third and one-half of all gastrointestinal injuries occur at the time of entry (30, 31) and unlike vascular injuries that are usually identified intraoperatively, only 30-50% of gastrointestinal injuries are diag­nosed intraoperatively, with the remainder diagnosed between 1 and 30 days postoperatively, leading to poorer outcomes (30, 32).

Extraperitoneal insufflation may occur when the insufflating needle is incorrectly placed or when carbon dioxide leaks around the insertion sites into the tissues. This minor complication may lead to extensive extraperitoneal insufflation that could result in failure of entry to the abdomen, visualization difficulties at the time of pri­mary port entry, and subcutaneous emphysema that usually resolves spontaneously and with minimal issue (33).

Types of entry techniques

Laparoscopic entry techniques may be divided into closed entry (using the Veress needle, or direct entry technique), open entry (using the Hasson method), or entry under laparoscopic vision.

Veress needle entry

Developed in 1938, the Veress needle is a common instrument used for peritoneal access in gynaecological surgery (32, 34). It consists of a 2 mm sharp outer needle, with a spring-loaded blunt inner stylet that retracts with tissue resistance through the abdominal wall and rapidly protrudes so the sharp needle is not exposed with loss of tissue resistance into the peritoneal cavity. After entering the peri­toneum, carbon dioxide fills the potential space, prior to insertion of the primary trocar with the aim of increasing distance between the anterior abdominal wall and abdominal structures using pressure as a guide (35, 36). This entry method has two blind steps—insertion of the Veress needle, and insertion of the trocar.

The umbilicus is the most widely used entry site for this technique, however Palmer's point, suprapubic, and transfundal approaches are all described. For women with known or suspected periumbilical adhesions, ‘Palmer's point' described as being 3 cm below the left costal margin in the midclavicular line may be used as an alterna­tive since adhesions rarely form in this location (37). Palmer's point should not be used in women with previous gastric or splenic sur­gery, or splenomegaly (38), and an alternate entry method should be considered (39).

Two prospective observational studies have been performed to determine the most reliable test for ensuring correct placement of the Veress needle; both found that the pressure profile test was the most sensitive and specific, when compared with the double click test, aspiration test, and hanging drop test (40, 41).

Direct entry

First described in 1978, direct entry involves an intraumbilical skin incision, followed by blind insertion of the primary trocar without prior insufflation, then inspection by the laparoscope to confirm intraperitoneal placement, prior to gas insufflation (42).

Hasson open entry

Open entry, via the Hasson approach, has no blind steps. The ab­dominal cavity is entered under direct vision through a small periumbilical incision. A blunt trocar is inserted under direct vi­sion, the laparoscope is then inserted, and pneumoperitoneum established (43).

Other entry techniques

Vision-guided direct entry requires a proprietary trocar and can­nula system inserted through the abdominal wall with concurrent laparoscopic vision using downward pressure or a screwing motion following Veress needle insufflation (44, 45). Radially expanding entry utilizes a progressively expanding sleeve over a Veress needle (46).

Comparison of entry techniques

A long-held and often heated debate exists as to which is the safest entry technique and there is no strong evidence that any entry tech­nique is superior in this regard. The Society of Obstetrician and Gynaecologists of Canada and American Congress of Obstetricians and Gynecologists state that practitioners should be proficient in Veress entry, open entry, and direct entry. The United Kingdom Royal College of Obstetricians and Gynaecologists and the French College of Gynaecologists and Obstetricians (CNGOF) similarly ac­knowledge that Veress, direct, and open entries are considered first- line procedures. CNGOF discourages the use of radially expanding and vision-guided entry techniques due to the lack of evidence for their efficacy. The Royal Australian and New Zealand College of Obstetrics and Gynaecology (RANZCOG) supports the use of um­bilical, suprapubic, and the Palmer point Veress needle entry, Hasson open entry, and direct entry. RANZCOG fellows are encouraged to use the entry technique that they are familiar with (47). Table 47.2 summarizes the various meta-analyses published over a number of years that have tried to combine data and report on safety outcomes; however, it has been estimated that RCTs on the subject will never be undertaken with more than 800,000 subjects required to determine an answer (48).

Evidence suggests a higher risk of minor complications and failed entry during Veress placement when compared with Hasson entry (34, 49, 50). However, there is no statistically significant difference in major complications or mortality between the entry methods. It should be noted that these studies include a combination of gy­naecological surgery and general surgery, there are limited data on patients with extremes of BMI and previous abdominal surgery, and different studies used different Veress techniques (Table 47.2) (47).

Table 47.2 Studies comparing entry techniques in laparoscopic surgery