17.2. Laparoscopic Ultrasonography:
Port Placement Arrangements
Maurice E. Arregui, M.D., F.A.C.S.
Matthew S. French, M.D.
A. Introduction
Appropriate port placement greatly facilitates the evaluation of intraabdom- inal structures with laparoscopic ultrasound. Thorough preoperative planning is essential to ensuring a smooth and efficient examination. Two main factors must be considered before selecting trocar sites. First, of course, is the procedure to be performed and organs to be examined, and the second is the type of equip- ment available.
B. Procedures
As surgeons have become aware of the benefits of laparoscopic ultrasound, the procedure has become increasingly popular. Many articles have been written in the past 5 years describing the use of ultrasound during a variety of general surgical, gynecologic, and urologic procedures. In addition, laparoscopic ultra- sound may be the primary procedure to be carried out during staging laparoscopy for pancreatic or other malignancies. Obviously, the location of the organ or organs to be examined will dictate the most appropriate locations for the trocars.
Frequently, when ultrasound is performed in conjunction with other procedures, the trocar sites selected for the primary procedure will suffice for the ultrasound examination.
C. Equipment
In general, three types of laparoscopic ultrasound probes exist: rigid, two- direction articulating (up/down), and four-direction articulating (up/down, side/
side). These probes are used in conjunction with a free-standing ultrasound module similar to those found in radiology departments, which consist of a monitor, keypad, and recording device or devices. The operating room setup for laparoscopic ultrasound is detailed in the preceding chapter.
ultrasound, the port arrangements shown in Figures 17.2.1, 17.2.2, and 17.2.3 permit laparoscopic examination of the commonly examined upper abdominal structures (liver, bile ducts, pancreas, stomach, etc.). The use of 10-mm ports allows the ultrasound-guided (USG) probe to be inserted via any of the ports, which should facilitate a thorough examination.
In the authors’ opinion, the best arrangement for diagnostic ultrasound is that depicted in Figure 17.2.1. Using this port scheme, the ultrasound probe is best placed through the umbilical port while the laparoscope is inserted through the right upper quadrant port. The surgeon can easily control both camera and probe while standing on the patient’s right side. If a four-direction articulating probe is used, the entire evaluation can be performed through the periumbilical port. If, however, a rigid probe or two-direction articulating probe is used, then a third port may be needed to complete the examination. When evaluating the liver and bile ducts, the epigastrium just to the right of the midline is the best additional location (see Figure 17.2.2). This position will allow transverse imaging whereas the umbilical position permits only sagittal imaging. The higher location of the epigastric port also allows better access to the dome of the liver. For examination of the pancreas and stomach, the left upper quadrant is probably the best location for a third port (see Figure 17.2.3). This location will facilitate transverse imaging of these structures.
Some surgeons routinely place the ultrasound probe in the right upper quad- rant for evaluation of the biliary structures (e.g., Kelly et al.). This technique can result in difficulty evaluating the lower edge of the liver due to its close proximity.
The dome and posterior portions of the liver can be very difficult to evalu- ate from any port position if a rigid probe is all that is available. Keeping good surface contact under these circumstances is not possible. In this situation, instil- lation of saline over the dome of the liver will often provide an acceptable window for standoff imaging.
Lower abdominal imaging of the retroperitoneum or colon can almost always be accomplished via the umbilical port with an articulating probe. For pelvic imaging, trocar sites are selected that allow the probe to be positioned adjacent to the structures of interest. The umbilicus is usually a suitable loca- tion; however, some patients may require trocars placed in the lower quadrants.
Once again additional ports will be required if the surgeon wishes to obtain images in a second plane and does not have access to an articulating ultrasound probe.
E. Conclusion
Optimal port site locations for laparoscopic ultrasound vary with respect to the patient, the procedure performed, and the equipment available to the surgeon.
Currently, optimal equipment is not readily available in most operating suites
Figure 17.2.1.Trocar placement for laparoscopic ultrasound of the liver, gallbladder, bile ducts, and pancreas. The ultrasound probe is placed through the umbilical port, and a 5-mm scope is placed through the right upper quadrant port.
Figure 17.2.2Alternate trocar arrangement that is useful when using a rigid ultrasound probe. The probe is placed through the umbilical port for sagittal imaging and through the epigastric port for longitudinal transverse imaging.
Figure 17.2.3.Trocar placement in the left upper quadrant for evaluation of the pancreas and stomach.
F. Selected References
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