and Robotic Access

Fig. 1.1

(a) Veress tip—spring-loaded inner core retracts once the tip of the Veress needle traverses the muscle and enters the abdominal cavity. (b) Veress placement. Holding the Veress securely helps in accurate placement. Opening pressures of the pneumoperitoneum should be less than 10 mmHg

Today, the Veress needle has a bore of 2 mm and comes in lengths from 12 to 15 cm. It works on the exact same premise of an outer beveled needle with an inner spring-loaded stylet that springs forward again upon entry into space as described by Veres over 75 years ago. The Veress needle is the most common method used to gain peritoneal access. Out of 155,987 gynecological laparoscopic procedures, the Veress technique was used to gain access in 81%. Alternatively, out of 17,216 general surgery procedures, the Veress needle was used for access in 48%, whereas 46% employed the Hasson technique (the remaining 6% were accessed via the direct trocar insertion technique) [4].

The most common site of placement of the Veress needle is at the umbilicus. This is because this is the only location in the abdomen where there is no muscle or fat between the skin and peritoneum. Previous scars near this site, or a site on the abdomen, should dictate that the Veress needle be placed in another location—typically a minimum of 6 cm from the scar. Umbilical hernia is a contraindication to placement of the Veress needle in this location. Furthermore, the Veress needle may be introduced at any point throughout the abdomen and is usually based on surgeon preference and comfort level, as well as regard to the procedure being performed. It is always wise to study available imaging to check for anatomic abnormalities or variations, such as hepatomegaly or splenomegaly. Also, one should remember that if the patient is in the flank position, needle placement too far laterally can result in retroperitoneal insufflation. Selection for placement of the Veress needle should be away from subsequent first trocar location placement, since introduction of the trocar will push down on the abdominal wall, with consequent potential advancement of the tip of the Veress needle downward toward bowel.

The main advantage of using the Veress needle is quicker entry into the abdominal cavity, as well as a potentially reduced risk of a port-site hernia. The disadvantage of the Veress needle is a slightly increased risk of complications due to its blind placement, such as bowel insufflation or bleeding, albeit a rare occurrence.

It is important that the stopcock on the Veress needle be open during its passage; this allows for the entry of air through the needle so that the bowel and omentum drop away from the elevated anterior abdominal wall. There are several ways to determine successful placement of the Veress needle in the peritoneal cavity (Fig. 1.1b):

1.

Two “clicks”—two clicks are usually heard upon successful passage into the peritoneal cavity. The first click is heard when the needle traverses the fascia of the abdominal wall and the second as it is passed through the parietal peritoneum.
2.

Aspiration—a saline-filled syringe is attached to the Veress needle and aspirated to make sure there is no return of blood or succus. If either of these contents is aspirated, the Veress needle can be removed with plans for careful inspection of intra-abdominal contents once the peritoneal cavity is safely accessed.
3.

Hang drop—it involves placing a drop of saline on the external surface of the Veress needle. If the saline drops quickly down the needle and disappears, then the needle is likely properly placed within the peritoneal cavity
4.

Low opening insufflations pressures—once the needle is in place and the CO₂ insufflation is begun, opening pressures below 10 mmHg generally confirm correct placement. Starting with a low flow of gas, confirming opening pressures <10 mmHg, and then increasing the gas flow rate is the most common and preferred approach by the authors.

Some surgeons may use a combination of the above techniques. The two “clicks” and low opening pressures obviously should be experienced upon every successful placement. There are some physicians who choose to omit the aspiration and hang drop test. A retrospective study did report that the double click, aspiration, and hang drop test were not confirmatory for proper placement of the Veress within the peritoneum. The same study reported that low opening insufflations pressure, less than 8 mmHg, was the most reliable method for confirming intraperitoneal placement [5]. The hang drop test may prove to be additionally helpful in confirming proper placement in morbidly obese patients, when opening insufflations pressures may be borderline high or equivocal simply due to the higher resting pressures created by the compression of the abdominal cavity by a very large pannus.

Some surgeons perform the “waggle” test, in which the needle is moved from side to side. They believe that free movement of the needle tip indicates a properly placed needle. However, this maneuver should actually be condemned, as it can easily turn a small, 1.6 mm hole in a vessel or bowel into a considerably more problematic situation by lacerating the tissue within.

In morbidly obese patients, one can start with increasing insufflation pressures temporarily to 20 mmHg, in order to counter the weight of the abdominal pannus, and then after successful trocar placement, the pressure may be reduced to a working pressure of 15 mmHg. The increase in pneumoperitoneal pressure can be safely elevated to 20 mmHg in patients without significant cardiac or pulmonary comorbidities. This step increases the distance between anterior abdominal wall and peritoneal contents, as well as producing a more taught abdominal wall, which is important for controlling the amount of axial force necessary for trocar passage into the abdomen [2]. It has been shown that this maneuver can lengthen the distance between aortic bifurcation and the umbilicus from 0.6 cm at a pressure of 12 mmHg to 5.9 cm [6]. One should remember to return the insufflation pressure to 15 mmHg upon successful placement of trocars.

The open, or Hasson, technique is performed by making a small skin incision and bluntly dissecting down to fascia. Stay sutures are then passed through the fascia on opposite sides and tagged with a hemostat. The fascia is then incised, creating an opening just large enough to pass the trocar. If this incision is larger than is needed, difficulty in maintaining pneumoperitoneum throughout the case may be encountered due to gas leaking out of the incision. Once the fascia is opened, blunt dissection may be used to dissect down to peritoneum. The peritoneum is then grasped with pickups or hemostats, brought out of the wound, and opened sharply. A finger is inserted into the peritoneal cavity to assess for any adhesions. The blunt-tipped trocar can then be safely passed into the peritoneal cavity under direct visualization. The fascial stay sutures are then used to secure the trocar to the fascia, thereby preventing dislodgement later in the case. Many ports designed for use with the Hasson technique offer a balloon on the distal end of the trocar that is inflated within the peritoneal cavity and then retracted upward to compress against the abdominal wall, thus minimizing accidental displacement and gas leaks. There may be a sponge on the proximal aspect of the trocar that may be compressed against the body wall to also help with securement of the port in addition to preventing gas leak. Disadvantages of the Hasson technique include increased time in placing this initial port, as well as an increased risk of gas leakage from the wound throughout the case, especially in obese patients. In cases of gas leaks from a port site, the leak can usually be minimized and pneumoperitoneum maintained by compressing Vaseline gauze around the leaking port site, by placing a sharp towel clamp around the skin edges, or by simply suturing the fascial opening closed so there is a better seal around the port.

Direct trocar placement by physical elevation of the abdominal wall, without creation of a pneumoperitoneum or absence of Hasson “open” technique, is not advised or recommended due to increased risk of injury.

Complications of Laparoscopic Access

Fortunately, injury rates during laparoscopic access are relatively low, with most sources reporting risks ranging from 0.05% to as high as 0.3% [7]. However, most feel that the rates of complications are vastly underreported. A survey of 407 Canadian gynecologists indicated that at least 25% of them had experienced access-related injuries [8]. It’s been postulated that most studies come from surgeons and centers of high volume, whose complications rates would naturally be lower once they are past the learning curve. Studies have indicated that 13–50% of vascular injuries and approximately 40–50% of bowel injuries are unrecognized until later in the postoperative period [2, 7].

One of the leading causes of death from laparoscopic access is major vascular injury, which carries a mortality rate as high as 15%. It is second only to anesthesia as the leading cause of mortality in laparoscopy [9]. It can occur during passage of the Veress needle or with placement of the trocar itself. Typically, injuries made with the Veress needle are self-limiting, and the Veress needle may simply be removed if no manipulation of the needle has occurred. In thin patients, the distance from the anterior abdominal wall to the retroperitoneum and its associated vascular structures may be as little as two centimeters [2]. The most commonly injured retroperitoneal vessel injured is the right common iliac artery, given that it lies just posterior to the umbilicus. However, any of the great vessels or their branches may lie in harm’s way.

Injury to the inferior epigastric vessels is the most common minor vascular injury. If the injury is recognized and bleeding is brisk, a Foley catheter may be inserted through the fascial opening, the balloon inflated, and traction held on the Foley so that the bleeding is temporarily tamponaded until further control can be obtained. Alternatively, some advocate nothing more than maintaining traction on the Foley balloon for 24 h with subsequent removal the next day. The same authors maintain that sutures may be placed full thickness through the abdominal wall above and below the bleeding site to gain immediate hemostasis, with removal of these sutures after 24 h [10]. This maneuver can be performed using a port closure device, such as the Carter-Thomason fascial closure device to pass suture above and below the site of bleeding in order gain hemostasis.

As stated previously, if a Veress needle is placed with immediate suspicion for vascular injury, it may be removed and placed in a different location, with vigilant subsequent inspection of the original site upon successful entry into the abdomen. Alternatively, the Hasson technique can also be employed at that time, depending on the surgeon’s discretion. If a trocar is passed and blood is noted to be pooling or welling in the trocar upon removal of the obturator, the trocar should not be removed. Rather, a high suspicion of great vessel injury should exist, with potential consideration for conversion to exploratory laparotomy. One should also be aware that not all vascular injuries are immediately apparent; some retroperitoneal bleeds may not be diagnosed until the postoperative period.

Bowel injury is the third leading cause of death from laparoscopic procedures, behind anesthesia and vascular injury. Unfortunately, bowel injuries are often not recognized intraoperatively, and diagnosis may occur in a delayed fashion after the patient’s condition has deteriorated significantly. A bowel injury carries a mortality rate of 2.5–5.0% [2, 7]. It has been found that delayed recognition and patient age greater than 59 were both independent predictors of death in cases of bowel injury. One complication that can be easily missed is through-and-through passage of a trocar through a loop of bowel. In other words, the trocar has passed through the lumen of the bowel and comes out of the other side, with no real visual evidence of an injury, unless the surgeon passes all secondary trocars under direct vision and then goes back and visualizes the initial port as well (if a closed technique was used). To decrease this risk of injury, keeping the instruments in the field of view is paramount, as well as not forcing instruments when passing them from the lateral assistant trocar. If resistance is felt, the advancement of the instrument should stop immediately and the camera panned back to visualize the insertion through the trocar.

Recognizing these bowel injuries as early as possible is extremely important in mitigating the risk of patient mortality and in reducing morbidity. The most common presentation is “severe single trocar site pain, abdominal distension, diarrhea, and leukopenia followed by acute cardiopulmonary collapse secondary to sepsis within 96 h of surgery” [11]. Bishoff et al. also reported that nausea and vomiting, ileus, and generalized abdominal pain were not common presentations. None of the patients had leukocytosis or peritoneal signs; only one had a fever greater than 38 °C. A high index of suspicion is paramount, and a CT scan with oral contrast can be obtained if concern exists in the postoperative period.

Bhoyrul et al. [12] studied 629 trocar injuries during a 3-year period using data obtained from the Food and Drug Administration (FDA). Manufacturers are legally required to report incidents involving medical devices as dictated by the Safe Medical Devices Act, passed by Congress in 1990. In turn, hospitals are obligated to report device-related deaths to both the FDA and the manufacturer. Serious injuries may be reported to the manufacturer or FDA; the manufacturer is then required to disclose these injuries to the FDA within 30 days in the prior scenario. In their study, out of 629 trocar injuries, there were 32 deaths, with 26 (81%) due to vascular injuries and the other 6 (19%) being due to visceral (mostly bowel) injuries. Of these vascular injuries resulting in patient death, 23% involved the aorta and 15% were a result of trauma to the inferior vena cava. The rest were attributable to injury to the iliacs or other vessels. Regarding deaths due to bowel injuries, none were recognized intraoperatively. It should also be noted that in four of these cases, one involved a bleeding disorder undiagnosed prior to surgery, one had an abdominal aortic aneurysm that was unknown before surgery, one involved a trocar reinsertion into the abdomen without reinsufflating the abdomen, and one was a surgeon’s first case. In looking at all injuries in the series—not just those involving mortality—it should be noted that bowel and vascular injuries occurred concomitantly in 9% of cases.

One must keep in mind patient anatomy during laparoscopic port placement. The distance between the retroperitoneal vessels and the anterior abdominal wall is only 3–4 cm and can be as little as 2 cm in thin patients. However, by inducing pneumoperitoneum or by manually raising the abdominal wall anteriorly with towel clips next to the area of planned trocar insertion, this distance may be increased to 8–14 cm [12]. One should also take extra care when placing trocars in those with abdominal wall laxity, such as those with atrophy of the muscle of the anterior abdominal wall and in females with a history of multiple pregnancies. This scenario will bring the anterior abdominal wall closer to the retroperitoneal vessels during port insertion if one is not careful. When inserting ports in the umbilicus, it is generally recommended that port insertion should occur at a 90° angle to the skin to gain direct entry into the abdomen instead of skiving the surface. Also, one should be aware that the bifurcation of the aorta is approximately at the level of the iliac crest. One of the most important tenets of laparoscopy is the need to control the axial force of entry during port placement; this may be the single most important step in preventing a catastrophic vascular injury . The axial force required for successful, safe trocar placement in each patient is different and is a learned motor and cognitive skill, with some reliance on muscle memory. It has been noted in studies that controlling the axial force is less difficult when the force needed is minimal in relation to the total upper body strength of the person passing the trocar [13]. Other factors that should be kept in mind as it relates to muscle memory and proprioception are the height of the table and the need to resist the urge to reach across the table to place a lateral port [7]. Trocars should be directed toward the organ of interest in order to avoid tearing of the fascia with subsequent placement of instruments and dissection.

Finally, laparoscopy and port placement do carry with it the small risks of a carbon dioxide gas embolism, which can potentially be fatal. The incidence has been reported to be 0.001% in a review of 489,335 closed laparoscopy cases. This complication has not been reported with open laparoscopic techniques [2, 14]. The patient may experience arrhythmias, tachycardia, cyanosis, and ultimately cardiovascular collapse. The anesthesiologist will see a sharp rise in the end-tidal CO₂ and a mill-wheel murmur may be auscultated. If this occurs, the surgeon should immediately desufflate the abdominal cavity and the patient should be placed in the left lateral decubitus position with the head down (Durant’s maneuver). This results in a reduced amount of gas advancing from the right side of the heart into pulmonary circulation, allowing the gas to remain in the right heart until it is slowly absorbed [6]. Additional methods that may be utilized if this is unsuccessful include hyperventilation to increase carbon dioxide excretion, insertion of a central venous catheter or pulmonary artery catheter to aspirate the gas, or, in rare refractory cases, hyperbaric oxygen that has shown some success in treatment of gas embolism [15, 16].

Types of Trocars

There are several types of trocars currently available. The authors’ preference is to use a bladeless dilating trocar for subsequent decreased risk of hernia (Fig. 1.2a). Other alternatives are disposable, shielded cutting trocars, visual entry trocars, and radially expanding trocars. All of these are placed after initial insufflation of the abdomen with a Veress needle and always under direct visualization. With placement of any trocar, it is important to remember to extend the index finger of the dominant hand that is advancing the trocar to serve as a limit to how deep the trocar may be inserted. Our preference as well is to use an optical access visualizing obturator, which allows the 5 or 10 mm laparoscope to be placed within the shaft of the trocar and allows direct visualization of the layers of muscle and subcutaneous fat as the tip of the trocar traverses the layers in order to identify entry into the abdomen (Fig. 1.2b).