Approach Considerations
Before making a skin incision for obtaining the pneumoperitoneum required in exploratory (diagnostic) laparoscopy, the following should be checked:
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Light source is working, along with a camera that is focused and white balanced
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Carbon dioxide tank is full, and an extra tank is available in the room
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Irrigation-aspiration unit is working
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Electrocautery unit is functional
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Insufflation is checked for flow and proper shutoff response to kinking of the tubing
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When closed pneumoperitoneum is planned, a Veress needle is checked for flow and proper tip retraction
Creation of Pneumoperitoneum and Port Placement
Depending on the procedure, the access port is often placed in the infra- or supraumbilical region. However, the initial site of port placement should be chosen according to the suspected pathology and the planned therapeutic procedure, with particular attention to avoiding previous abdominal scars.
The pneumoperitoneum can be achieved by means of either closed or open methods. In the closed method, a 14-gauge Veress needle (disposable or reusable) is used to enter the peritoneal cavity. Before the needle is inserted, it is of critical importance to check patency and appropriate retraction of the tip. After an initial nick on the skin, the abdominal wall is lifted with a firm hand grasp or towel clips, and the Veress needle is inserted through the linea alba and away from previous scars.
Entry into the peritoneal cavity is suggested by a sudden release in resistance and can be confirmed by several methods, including aspiration of the Veress needle or suctioning of a saline droplet placed at the hub of the Veress needle.
Once intraperitoneal position is confirmed, the carbon dioxide insufflation is started. The opening pressure should not be elevated (< 5-6 mm Hg). An elevated initial insufflation pressure may reflect clogging of the Veress needle, a kink in the insufflation tubing, inappropriate placement of the Veress needle tip in preperitoneal space or against omentum, inadequate skeletal muscle relaxation, or, in the worst scenario, the needle lying inside the intra-abdominal organs.
The open or Hasson technique of creating a pneumoperitoneum is accomplished by making a small skin incision and dissecting down to the rectus fascia. Stay sutures are laced with 0 absorbable suture material on either side of the fascia, after which the peritoneum is identified and grasped with Kocher or Allis clamps and opened with scissors. Confirmation of entry into the peritoneal cavity can be achieved with visualization of the omentum or small bowel or by digital palpation of the smooth intra-abdominal structures.
A Hasson port is placed and secured in place with the fascial sutures, and the inner obturator is removed. The stay sutures are also used to close the abdominal wall. The insufflation tubing is attached to the side port of the trocar, and the abdomen is inflated rapidly to 15 mm Hg. Additional ports are placed as necessary for tissue manipulation, biopsy, or therapeutic maneuvers.
Initial Inspection of Peritoneal Cavity
After port placement, a detailed examination of the peritoneal cavity is performed.
In patients presenting with acute abdominal pain, depending on the site of suspected pathology, all relevant structures (including gallbladder, appendix, colon, and any other likely affected sites) are grossly examined for signs of inflammation (eg, swelling, erythema, fibrinous exudates, inflammatory adhesions, or formation of phlegm). It is important to note the nature of ascitic fluid (clear vs purulent) to rule out intra-abdominal abscesses. In the presence of an obvious pathology, a therapeutic procedure (laparoscopic or open) can be undertaken simultaneously.
In patients with intra-abdominal malignancy, a systematic examination of the primary tumor site as well as all abdominal viscera and the pelvis is performed to identify gross evidence of metastasis. The primary tumor is assessed to detect direct extension into contiguous organs. If there is evidence of widespread or peritoneal-based disease or liver metastasis or if there is a direct extension of the primary tumor to surrounding structures that renders the tumor unresectable, diagnostic laparoscopy is terminated after confirmatory biopsy specimens are taken.
Placement of Additional Ports
After initial inspection, additional ports can be placed to further explore the areas of interest or to perform a therapeutic procedure. The number and site of port placements depends upon the anatomic region of interest, as well as the planned procedure.
In general, to achieve a desirable operative dexterity, the ports should be placed to form an equilateral triangle or a diamond, with the camera and the distance to the operative target taken into account. Then, 5- or 10-mm additional ports are placed after incision of the skin under direct visualization to prevent unintended injuries.
Staging Laparoscopy for Intra-abdominal Cancers
After inspection of the peritoneal cavity, a systematic examination of the intra-abdominal organs is performed, starting with the liver. The operating table is placed in reverse Trendelenburg position (20-30º) with 10-15º of left lateral tilt. This maneuver pushes surrounding structures, especially the small bowel and omentum, away from the liver and facilitates hepatic examination. Examination of both surfaces (anterior and posterior) of the left lateral section of the liver is carried out, followed by similar examination of the superior and inferior surfaces of the right hemiliver.
Systematic palpation of liver surfaces to detect small tumors is performed with blunt-tip suction or stone-extracting forceps. The examination of diaphragmatic and posterior surfaces of the liver is accomplished by placing the camera in the right upper quadrant or epigastric port(s). Subsequently, the hepatoduodenal ligament, the hilum of the liver, and the foramen of Winslow are examined. Biopsy of abnormal or enlarged lymph nodes is performed with the cup forceps.
In patients with pancreatic or periampullary tumors, meticulous examination of the angle between the duodenum and the lateral aspect of the common bile duct (CBD) is performed to rule out direct tumor infiltration and hepatic artery encasement.
Subsequently, colonic mesocolon is examined by repositioning the patient in a 10º Trendelenburg position without lateral tilt and retracting the omentum towards the left upper quadrant. This maneuver is further facilitated by elevating the transverse colon, which allows the ligament of Treitz to be identified. Careful visual inspection of the mesocolon is performed, and any suspicious nodules or nodes can be biopsied.
The patient is then returned to a supine position. For the majority of patients with upper gastrointestinal (GI) tumors, this is the limit of the staging laparoscopy. However, in patients with pancreatic cancer, it is important to assess the lesser sac and celiac axis. This maneuver is performed by elevating the left hemiliver and incising the gastrohepatic omentum to gain entrance into the lesser sac.
With an angled or 30º laparoscope, a systematic examination of the anterior aspect of the pancreas, the hepatic artery, and the left gastric artery is performed. The caudate lobe of the liver, the inferior vena cava (IVC), and the celiac axis are also examined. Celiac, portal, perigastric, and hepatogastric nodes are examined and can be biopsied if they appear suspicious.
Laparoscopic Ultrasonography
Standard diagnostic laparoscopy is a two-dimensional modality that permits excellent visualization of the peritoneal structures. However, it is limited by the lack of tactile sensation. The inability to see the undersurface of the organs can limit the utility of laparoscopic staging. Direct palpation of the liver with blunt laparoscopic instruments may be useful. However, identification of small tumors or precise delineation of the anatomic relation of a tumor to adjacent structures is often difficult or impossible.
Laparoscopic ultrasonography (LUS) is an excellent adjunct to traditional laparoscopy and can be rapidly performed. LUS probes (curved- or linear-array technology) with high-frequency (6-10 MHz) performance permit high-resolution images to be obtained and can detect lesions as small as 0.2 cm within the hepatic parenchyma.
Color Doppler assessment can also be performed to allow accurate identification of blood vessels. Though primarily used for assessment of the hepatic parenchyma, LUS has been used extensively for evaluation of the biliary tract and in the staging of upper GI malignancies, by allowing assessment of liver metastases, regional nodal disease, or local vascular involvement.
Nevertheless, the additional value of LUS remains controversial. A number of authors have suggested that LUS provides additional information in only 14-25% of patients during staging procedures, but some authors believe that the yield is much less. [37, 38]
Port Closure
Before the procedure is terminated, a meticulous examination is undertaken to ensure adequate hemostasis and correct instrument and gauze and sponge counts. Ports are removed under direct visualization to ensure that there is no visceral herniation or bleeding. An attempt should be made to decompress the abdominal cavity by expelling the pneumoperitoneum to reduce postoperative shoulder pain. All port sites larger than 5 mm should be closed with an absorbable suture, and the skin is closed with either continuous or interrupted subcuticular sutures.
