Peritoneal Access Before inserting the laparoscope, a primary cannula (or port) must be positioned in the abdominal wall to establish access to the peritoneal cavity. The closed technique is a blind approach in which the cannula is introduced with an obturator designed to penetrate the abdominal layers. In open laparoscopy, initial entry into the peritoneal cavity is achieved with minilaparotomy using either a transverse subumbilical or midline infraumbilical incision down to the rectus fascia, to which the cannula is fixed into position with sutures or other suitable techniques. Gynecologists generally favor a closed technique, preinﬂating the peritoneal cavity with CO2 through a hollow insufﬂation needle. In either case, additional cannulas are
Figure 23.3 Vascular anatomy of the anterior abdominal Figure 23.3 wall relative to the sites of port insertion. The location of the vessels that can be traumatized when inserting trocars into the anterior abdominal wall is indicated. The lateral trocars should be placed lateral to the inferior epigastric vessels that course medially to lie under the rectus muscle anterior to the posterior rectus sheath. The relative anatomy of the left upper quadrant port site is shown: the closest structure is the stomach (A) (approximately 4 cm away) and the left lobe of the liver (B) approximately (4 cm away). The spleen (C) is approximately 12 cm away.
subsequently inserted under direct vision to allow the use of laparoscopic hand instruments such as scissors, probes, and other manipulating devices.
Insertion of the insufﬂation needle and primary cannula is aided by an understanding of the normal underlying anatomy, especially the location of the larger retroperitoneal vessels (Fig. 23.3). A “safety zone” exists inferior to the sacral promontory in the area bounded cephalad by the bifurcation of the aorta, posteriorly by the sacrum, and laterally by the iliac vessels (79). In women placed in the Trendelenburg position, the great vessels are oriented more cephalad and anterior, making them more vulnerable to injury unless appropriate adjustments are made in the angle of insertion (Fig. 23.4) (80). Therefore, positioning of the insufﬂation needle and the primary cannula is best accomplished with the patient in an unaltered supine (horizontal) position. This approach facilitates the evaluation of the upper abdomen, which is limited if the intraperitoneal contents are shifted cephalad by the head-down (Trendelenburg) position.
Virtually all insufﬂation needles are modifications of the hollow needle designed by Verres (Fig. 23.5). In cases uncomplicated by previous pelvic surgery, the preferred site for insertion is the base of the umbilicus, where the abdominal wall is the thinnest and usually avascular.
1. A midline infraumbilical incision adequate for the needle is made at the base of the umbilicus with a small scalpel, and the abdominal wall is maximally lifted, either manually or with instruments. Elevation is accomplished manually after affixing towel clips to the abdominal wall on either side lateral to the umbilicus or opposite one another within the edge of the umbilical incision itself (81).
Figure 23.4 Vascular anatomy. Location of the great vessels and their changing relationship to the umbilicus with increasing patient weight (from left to right).
Safe insertion of the insufﬂation needle mandates that the instrument be maintained in a midline, sagittal plane while the operator directs the tip between the iliac vessels, anterior to the sacrum but inferior to the bifurcation of the aorta and the proximal aspect of the vena cava. Because the sacral promontory is commonly covered in part by the left common iliac vein, vascular injury may occur in the midline below the bifurcation (82).