Each type of surgery—intraluminal endoscopy, extraluminal endoscopy (ie, laparoscopy), and open surgery—is defined by the manner of accessing the operative site. Getting this part of the surgery right is fundamental to the success of the whole procedure. For laparoscopy, this requires gas to be insufflated in the proper space, and that the sites for the video-laparoscope and instruments are established and maintained. In this chapter, we describe techniques and considerations for laparoscopic access to the kidney, including both transperitoneal and retroperitoneal approaches. A thorough knowledge of the various options for laparoscopic access provides the surgeon with the tools to avoid complications and perform the intended procedure with success.
Transperitoneal Laparoscopic Access
Choosing Sites of Access
The first step in obtaining transperitoneal laparoscopic access is choosing the optimal site for initial access. Typically, the initial site is the one for the video-laparoscope. As such, consideration of the best viewing location is important. The view of the operative field should be unobstructed by anatomic structures and provide appropriate angles that do not interfere with instruments. Additionally, the entry site should be free of adhesions (near surgical scars) or other anatomic problems (e.g., organomegaly, cysts) that might increase the risk of injury. Finally, knowledge of the abdominal wall configuration provides confidence in the “feel” of initial entry and reduces the chance of abdominal wall vessel injury. Fig. 28.1 illustrates a cross section of the abdominal wall. The simplest entry is in the midline, where fascial layers are fused. The peritoneum is a separate layer, except at the umbilicus where it is adherent to the fused fascia. Laterally, several additional layers of muscle and fascia are interposed between the skin and the peritoneal membrane.
The location of abdominal wall vessels should be considered during access site selection. The superior and inferior epigastric vessels are posterior to the rectus muscle, with branches that perforate laterally and medially. A puncture through the rectus muscle risks damage to these vessels. The superficial epigastric and circumflex iliac vessels fan onto the lower abdominal wall above the fascial layers. Any lower quadrant puncture may injure these vessels. The periumbilical venous plexus is usually not problematic, but in some patients they may be dilated and therefore more susceptible to injury.
For laparoscopic renal surgery, the initial entry is usually made in the umbilicus, the upper midline, or the ipsilateral upper quadrant. The distance lateral from the midline and cephalad from the umbilicus is determined by the size of the patient and the kidney. In thin and small patients, entry at the umbilicus or elsewhere in the midline might be appropriate. For obese patients, the optimal entry site might be closer to the costal margin. Although the initial entry site is usually where the videolaparoscope is placed, if the preferred areas are complicated by scars from prior surgery, then initial access can be obtained anywhere that is safe. Once the abdomen is insufflated, then additional ports, including the one that will eventually be used for the videolaparoscope, can be placed.
The most common tool for initial transperitoneal laparoscopic entry in urologic practice is the Veress needle, which has an inner, blunt-tipped obturator and an outer, sharply beveled sheath ( Fig. 28.2 ). The obturator is spring-loaded, such that it retracts when pushed against fixed structures (fascia and peritoneum) and allows penetration of tissue by the sharp sheath, but when against mobile structures such as bowel, the obturator protrudes and prevents puncture. To insert the Veress needle, first make a small nick in the skin with a scalpel. Holding the needle with thumb and forefingers, insert it with a motion of the wrist and fingers. The direction of insertion generally should be perpendicular to the abdominal wall, although for midline insertion the needle should be angled away from the great vessels. The number of palpable layers of resistance until the peritoneal cavity is reached varies from one to three, depending on the site of insertion and the patient’s body habitus. While the needle is being inserted, the surgeon should both feel and hear entry through these different layers. When resistance is lost, and the needle can be advanced a few centimeters freely, the correct space has likely been entered. Lifting up on the abdominal wall, as done by many surgeons, does not create more space in the peritoneal cavity, and may increase the depth of tissue that must be traversed to the peritoneal cavity, but it does create more abdominal wall tension against which to push the Veress needle, and likely increases the distance between the anterior peritoneum and the retroperitoneal vessels.
Next, perform a series of tests to assess for correct needle placement. Place a 10-mL syringe containing 5 mL of saline on the Veress needle, and aspirate back. If blood, bowel contents, or urine is aspirated back, then placement is incorrect. If there is no such material, then inject the fluid through the Veress needle and aspirate; again, there should be no return of material. These maneuvers will determine whether the needle tip is in a luminal structure, but will be unremarkable if the needle is preperitoneal, which is the most common erroneous placement. One maneuver that can help determine if access is intraperitoneal is the hanging drop of saline test. In this, a drop of saline is placed in the open needle hub and the abdominal wall lifted. If the tip of the Veress needle is within the peritoneal cavity, the drop is drawn into the needle. However, the possibility of incorrect placement is really only assessed by monitoring the intraabdominal pressure when insufflation is commenced. The pressure should not rise above 8 mm Hg within the first 500 mL of gas, or if it does, it should only be momentary and quickly corrected by a slight withdrawal, twist, and tilting up of the needle (which will free the needle tip from omental or mesenteric fat). If these conditions are met, continue insufflation. If these conditions are not met, then disconnect the insufflation tubing, allow the gas to escape, and withdraw the needle. One or two additional attempts are reasonable, perhaps at different locations, but continued failure should prompt the use of an alternative method of access.
Palmer’s point: Sometimes placing the Veress needle at Palmer’s point can avoid some of the uncertainties associated with correct entry into the peritoneal cavity. Named after the French surgeon, Raoul Palmer, who popularized the Veress needle technique, it is located in the left upper quadrant, 2 cm below the left subcostal border in the midclavicular line. This area for Veress needle entry can be considered in patients at risk of underlying adhesions (e.g., previous laparotomy) or those with a midline mass or hernia. However, it should not be performed in patients with previous splenic or gastric surgery, hepatosplenomegaly, or portal hypertension.
Open Entry Technique
An alternative method for transperitoneal laparoscopic entry is the “open” method to insert a blunt (Hasson) trocar-cannula, a balloon-tipped port, or the sleeve for a radially expanding port. This method is also commonly known as the Hasson technique. A blunt trocar-cannula ( Fig. 28.3 ), which is available from various manufacturers in reusable and disposable versions, consists of a blunt trocar, a cannula with an adjustable conical sleeve, and suture-holding arms for fixation. For the open entry technique, make an incision the size of the port to be placed (usually 12–15 mm) through the skin and use small retractors (e.g., S-shaped retractors) to expose the fascia in order to make a 1.5-cm incision. Place retention sutures on both sides of the fascia, incise the peritoneum under vision, and explore with a finger to ensure that the peritoneal cavity is free of adhesions. Insert the trocar-cannula assembly, and bring the cone into the peritoneotomy to create a tight seal. Pull the fascial stitches up and tie them around the arms of the assembly to hold it in place. Insert the balloon-tipped port ( Fig. 28.4 ), which is available as a disposable device from various manufacturers, in a similar manner, but with this device, retention and gas-tightness is attained by an inflatable balloon at the tip of the port pulled up against the underside of the abdominal wall and held snugly in place by a locking foam cuff. The radially expanding port (Step ports, Covidien, Mansfield, MA; Fig. 28.5 ), which is more commonly used as a separate port rather than for initial entry, can also be used with “open” laparoscopy for initial access. For this port, make the incision in the fascia and peritoneum only a few millimeters wide. Insert the mesh sleeve into the peritoneotomy and advance the dilating trocar-cannula assembly through the sleeve (see later for more detailed explanation of this device). Because the initial incision is smaller than the final port diameter, gas leakage with this technique tends to be less than with the blunt trocar-cannula (gas leakage with the balloon-tipped port also tends to be minimal). Some laparoscopists obtain initial access using a Hasson technique in all cases, some use it when confronted with a patient with suspected abdominal adhesions or other anatomic abnormalities, and others use this technique only if Veress needle insertion fails.