Avoiding Trocar Injuries Associated with Laparoscopic Surgery
Feb 2012 – by D. Soper, MD
Editor: Roger Smith, MD
REVISED PEARL Ė June 2015
Up to half of major intraoperative complications associated with laparoscopy, including major vascular injury, occur at the time of surgical entry. Half of all bowel injuries occur during entry, with the small intestine at highest risk. Insertion of the Veress needle and primary trocar for initial entry account for 40% of complications and the majority of fatalities.
The usual site of entry into the abdomen is in the midsagittal plane at the lower margin of the umbilicus. For safe insertion, instruments need to be placed parallel to the long axis of the patient so that the tip remains in the midline. Deviations of as little as 20 mm from parallel place the instrument tip almost 4 cm from the midline. Patients should NOT be in Trendelenburg position during initial trocar insertion.
In non-obese women, the Veress needle or trocar should be inserted at 45 degrees from the horizontal plane of a patientís spine. At this angle, the abdominal wall thickness varies from 2 to 3 cm and distance to the major vessels averages 6 to 10 cm. In obese patients, the needle or trocar can be placed close to 90 degrees from the horizontal plane. At this angle, the distance to the vessels averages 13 cm.
The Veress needle should be open when inserted. The surgeon can feel or listen for two clicks (the double click test) as the needle is placed through the anterior abdominal wall (click #1 = anterior rectus sheath, click #2 = the peritoneum). The needle should be freely movable at a fulcrum located within the anterior abdominal wall (waggle test). A drop of saline can be placed in the open needle hub and the abdominal wall lifted (hanging drop test). If the drop is drawn into the needle, it suggests that the tip is within the abdominal cavity.
Many surgeons prefer to insert the primary trocar after insufflation of the abdomen to 25 to 30 mm Hg. This stiffens the anterior abdominal, preventing the umbilicus from being depressed toward the major vessels.
Open laparoscopy avoids blind placement by incising the periumbilical fascia and peritoneum and advancing a blunt trocar directly into the peritoneal cavity.
In direct trocar insertion, the primary trocar is placed without prior insufflation and may avoid associated with Veress needle placement but not decrease overall risk of injury.
Alternatively, left upper quadrant insertion at Palmerís Point can be used. This point is located 3 cm below the middle of the left costal margin. The Veress needle is inserted perpendicular to the patientís skin. A small diameter scope can be placed, and other trocars then placed under direct visualization. This is especially helpful in patients who have had prior abdominal surgery.
For insertion of secondary ports, transillumination can help to identify superficial vessels, but they are difficult to see in the obese patient. The umbilical ligaments can be identified and the inferior epigastric arteries visualized arising from the inguinal ring. When laparoscopic landmarks are not visible, secondary trocars should be placed 5 cm superior to the midpubic symphysis and 8 cm lateral to the midline to avoid the epigastric vessels. This location is often directly over the external iliac vessels, so care should be taken to control the direction, depth and speed during insertion. The trocar should be placed as close to possible to perpendicular to the abdominal wall and peritoneum. A more oblique insertion can make entry into the peritoneal cavity more difficult as the distance from insertion site to peritoneal cavity increases. Once the trocar sleeve is through the peritoneum, the sheath can be further advanced under direct observation, preventing injury to the underlying structures.
Prior to incision of the skin and trocar insertion, injection of local anesthetic using a 1.5 inch needle along the projected trocar insertion allows identification of where the needle will enter the peritoneum and provides perioperative anesthesia.
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