Methods

After the patient is anesthetized, she is placed in a supine or dorsal lithotomy position and draped.  It is of utmost importance that the patient’s abdominal muscles are completely paralyzed and that she remains parallel to the floor (i.e. flat, without Trendelenburg positioning). An oro-gastric tube is inserted and bladder is drained to avoid distention of these organs. After palpation for anatomic landmarks including the sacral promontory and the pulsations of the abdominal aorta, the LapCap can be used to accomplish Veress needle insertion.

The device itself consists of a transparent dome with a central needle pass-through port (Figure I).  The dome is connected to a regular wall vacuum line via a lateral port.  We have used it in three different ways.

1. Suction first

The Veress needle is selected based on the patient’s body habits.  Whereas a 12cm sharp, disposable Veress needle can be used for very thin patients, a 15cm needle is ideal for patients of average or heavier body mass index. The LapCap is placed over the peri-umbilical area with the needle pass-through port roughly centered over the umbilicus itself.  

Sterile suction tubing is connected to the LapCap vacuum line port and maximum standard wall suction is applied. This suction elevates full-thickness abdominal wall into the dome, creating a cone-shaped vacuum space of peritoneal cavity within the LapCap dome. No incision is necessary as suction will draw blood from the skin incision. The suction is then released and the abdominal wall is allowed to fall back into place.  This process is repeated approximately three times in order to ensure adequate relaxation of the abdominal wall and to help to displace the omentum from the anterior abdominal wall.  Suction is applied one final time and, with the abdominal wall elevated within the device, the Veress needle is advanced through the LapCap needle pass-through (Figure II). In the very thin patients, we insert only a small portion (5 cm) of a 12 cm needle. However, in average or obese patients, we often insert the full length of a 15 cm needle. Usually, a triple-click indicates passage through the skin, fascia and peritoneum, but we cannot rely on these clicks as they may not be appreciable. 

Intra-abdominal placement of the needle cannot be confirmed by the “saline drop test”¹³ as it is not feasible for the drop of saline to fall freely into the abdominal cavity in the setting of the vacuum. However, the instillation and aspiration of 3-5 cc of saline through the Veress needle is recommended so as to dislodge any small fragments of skin or tissue which might obstruct gas flow through the needle. It also negates theoretical concern of blood and bowel aspiration. Insufflation may then commence. 

We have discovered that the pressure reading with the LapCap in place is elevated to almost double the actual intra-abdominal pressure because of the smaller volume of the abdominal cavity associated with sequestration of a portion of the abdominal wall with in the Lap Cap. While using a Veress needle without the support of the LapCap, an opening pressure below 10 mmHg was expected from intra-peritoneal placement.¹³ However, with the traction of LapCap, pressures up to 20 mmHg are associated with appropriate placement.

Insufflation can then continue with the flow of CO2 increased to 40 L/min.  Pneumoperitoneum should be established at an intra-abdominal pressure of 20 mmHg. When this pressure is reached, the stopcock connecting to the wall suction is turned off. We do not tighten the screw lock of the cap over the needle. The LapCap will spontaneously release itself from the abdominal wall and the intraperitoneal pressure will decrease significantly, usually to 10-12mm Hg.  The Veress needle then remains in place and insufflation is continued until the pressure reaches 20 mmHg again. 

When the intended pressure is achieved, the LapCap is removed (Figure III).  Some physicians may choose to proceed with mapping¹⁵ of the abdominal cavity in patients with prior surgery.  We recommend reinsertion of the Veress needle at a site separate from where the primary trocar is to be placed (often a few centimeters lateral to the umbilicus to either side or in the the left upper quadrant) prior to mapping; otherwise gas leakage may slightly reduce intra-abdominal pressure. A high level of intra-abdominal pressure at the time of trocar entry is recommended so as to increase the distance between the abdominal skin and vital underlying organs and vasculature.¹⁶ 

Following these steps, the abdomen is ready for insertion of the trocar without any need to elevate the abdominal wall. After safe entry, the intra-abdominal pressure should be decreased to a maximum of 15 mmHg.

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