Operative Laparoscopy

Background

Operative laparoscopy has become the standard approach for most common surgeries, including tubal ligation, cholecystectomy, appendectomy, and ovarian cystectomy (see the image below). ^[1]

Currently, technology is so advanced that almost all surgical procedures can be performed laparoscopically. The laparoscopic approach has been gaining popularity for several reasons:

• Usually can be performed in the outpatient setting

• Shorter hospitalization when admission is necessary

• Better cosmetics

• Faster recovery and earlier return to normal activity

• Less risk of postoperative adhesion formation

The higher cost of the procedure may be outweighed by social benefits, including lack of or shorter hospitalization and earlier return to work.

The video below depicts a single-incision laparoscopic cholecystectomy.

Indications

Almost any gynecologic surgery can be performed laparoscopically in carefully selected patients and in the hands of a skilled minimally invasive surgeon. Advancement in technology and the availability of a wide spectrum of laparoscopic equipment and energy sources have allowed a large variety of surgery to be performed laparoscopically, ranging from simple tubal ligation to complex urogynecologic and oncologic procedures. ^[2]

Contraindications

Absolute contraindications for operative laparoscopy include the following:

• Surgeon's lack of skills

• Inadequately equipped operating room

• Shock

• Markedly increased intracranial pressure

• Retinal detachment

Relative contraindications include:

• Compromised cardiopulmonary status

• Ventriculoperitoneal shunt ^[3]

• Pregnancy

• Large pelvic masses

Technical Considerations

Best Practices

To document correct intraperitoneal placement of the initial trocar, we recommend using serial gas pressure measurement. It has been shown to be the best indicator of correct placement of the initial trocar (100% sensitive for preperitoneal insufflations).

In obese patients or patients with suspected pelvic adhesions, we routinely choose the left upper quadrant site and use the direct entry technique using a 5-mm optical trocar and 5-mm 0-degree scope. We find that the close proximity of this site to the lower rib requires less force to lift the anterior abdominal wall as compared to the umbilical site. This is especially practical in obese patients and can be performed by the surgeon alone without assistance.

Always make sure that a nasogastric or orogastric tube is placed and the stomach is deflated prior to performing a left upper quadrant entry.

Complication Prevention

Preperitoneal insufflation can occur when the Veress needle is mistakenly placed in the preperitoneal space and insufflations are started. This can prevent entry inside the peritoneal cavity and can create a false space with potential injury to the underlying vascular structures. It is one cause of conversion to laparotomy. ^[4]

Omental emphysema can occur when the Veress needle is inserted into the omentum and appears as gas bubbles within the omentum. It is rarely of clinical consequence. Elevation of CO₂ levels has been reported. ^[5]

Most wound infections are superficial and consists of wound cellulitis. However, more serious infections and wound abscesses rarely occur, especially in the context of a contaminated surgery like pelvic abscesses, ruptured appendix, or bowel injury. Most of these infections are treated conservatively with bedside drainage, wound packing, and antibiotics. Severe necrotizing fasciitis can rarely occur. ^[4] The American College of Obstetricians and Gynecologists (ACOG) does not recommend prophylactic antibiotics in patients undergoing diagnostic laparoscopy. ^[5]

Bowel injury can occur during closed-entry or open-entry technique. However, the incidence seems to be the lowest during open entry (0.048%) versus closed entry (0.083%). ^[6] The risk of bowel injury increases in the context of bowel adhesions, such as a history of previous surgery, pelvic inflammatory disease, and endometriosis. Bowel injury is concerning because these injury can be missed during the surgery and present postoperatively with peritonitis and sepsis.

Injury to a major retroperitoneal vessel is a catastrophic complication and occurs most commonly during laparoscopic entry when blindly placing the Veress needle or primary trocar through a periumbilical incision. ^{[7, 8]} However, vascular injury can occur regardless of the method of entry because of the short distance between the base of the umbilicus and the major retroperitoneal vessels, which can be as little as 2 cm. ^[9] The incidence of major vascular injury ranges between 0.04 and 0.5%. ^{[10, 11]}

Accidental placement of the Veress needle and insufflating into a major vein can result in a massive gas embolism. Injuring any of the major vessels can result in fatal exsanguination.

Injury to the deep inferior epigastric vessels can cause subcutaneous hematoma and significant morbidity. ^[10]

Recommendations from ACOG emphasize that laparoscopy can be more complicated in obese patients, and the risk of conversion to laparotomy is increased in this setting. ^[12]

Equipment

A typical operating room setup in shown in the image below.

Camera

The current laparoscopic cameras use three chips, each detecting one of the primary colors: red, green, and blue. The mixture of these primary colors in different proportions allows the camera to capture all colors. Three-chip cameras generally provide the highest fidelity. The camera head attaches to the laparoscope and a cable connects to the camera control unit. The signal is then transmitted to the monitor, which converts the electric signal to an analog image (see the image below).

Light Source

Light sources most commonly use xenon bulbs, which provide the highest light intensity and are long lasting, although they are more expensive than halogen lamps. The light cable connects the source to the scope. There are 2 types of cables: fiber optic and liquid crystal gel cables. The fiber optic cable is composed of a bundle of optical fiberglass threads swaged at both ends. The liquid crystal cable consists of a sheath filled with a clear optical gel and made rigid by a metal sheath, making it more difficult to store and maintain. The liquid crystal gel cable transmits more heat and more light than the fiber optic cable. Both cables are fragile and need to be handled with care. Twisting of the cable should be avoided. A damaged cable will provide a suboptimal image.

Once turned on, the surgeon has to adjust the focus and the white balance. Focusing the camera is performed at a distance of 5 cm from an object. Then white balance is performed to adjust the color. A white surface, typically clean gauze, is used. During this process, the white color becomes a reference against which to adjust the three primary colors.

Insufflator

The insufflator delivers CO₂ gas into the peritoneal cavity (see the image below).

CO₂ gas is preferred because it is noncombustible, soluble, and cheap. Being soluble prevents air embolism. There are two important settings on the insufflator: flow and pressure. The flow setting dictates the flow rate in liters per minute; it is set low during the initial insufflation process and then higher during the procedure.

During operative laparoscopy, CO₂ gas is typically lost through leakage of the multiple ports and suctioning. In these cases, the flow rate can be set high. The pressure setting sets the upper limit of the intra-abdominal pressure. This is typically set at 15 mm Hg. The insufflator is automatic and delivers the flow of CO₂ as needed to maintain the desired intra-abdominal pressure. The following points can help with troubleshooting:

• A low flow and low pressure indicates an empty gas tank.

• A low flow and high pressure indicates an obstruction, typically kinked tubing, turned-off valve, or preperitoneal insufflation.

• A high flow and low pressure indicates a gas leak; this is typically associated with a hissing sound.

The CO₂ gas is delivered cold at a temperature of 21°C and dry at 0% humidity. Cold, dry CO₂ has been shown to cause peritoneal cell desiccation, to acidify the peritoneal surface, and to impair the mesothelial lining immune response. ^{[13, 14, 15]} A meta-analysis of 10 randomized trials involving 565 patients comparing heated and humidified CO₂ to standard CO₂ concluded that using heated and humidified CO₂ was associated with less postoperative pain, lower risk of hypothermia, and lower analgesic requirements. There was no difference in total hospital stay and lens fogging rate. ^[16]

Veress Needle

The Veress needle consists of a cannula with a needle point (see the image below). ^{[17, 18]}

Inside the cannula there is a blunt stylet loaded with a spring. When faced with resistance, the stylet is pushed inward, compressing the spring and allowing the cutting edge of the outer cannula to pierce the skin. Once the resistance is lost, the spring pushes the stylet forward and a click is heard. The click heard is used to indicate the level of penetration. The blunt tip extends past the cutting edge, protecting it. The Veress needle has lateral holes at its distal ends to deliver the CO₂. It comes in three different lengths: 80 mm, 100 mm and 120 mm (see the image below).

The Veress needle is used in a closed-entry technique to obtain pneumoperitoneum. The goal of the stylet is to prevent injury to soft tissue, which has lower resistance than the fascia and peritoneum.

Trocars

Trocars come in different sizes and lengths; they also have different tips and can be disposable or reusable. They range from 2 mm to 15 mm and can be sharp or blunt (see the image below).

The Hasson-type trocar is a blunt-tip trocar used in an open-entry technique.

The new optical trocars have clear conical tips and hollow cannula through which a scope can be placed to visualize the different tissue layers during insertion. Although the tip is not sharp, its shape allows tissue separation with twisting and countertwisting motions. Trocars were initially designed to limit injury to underlying structures. These trocars can be used during a closed-entry technique.

The radially expanding trocar (VersaStep, Covidien) is bladeless and consists of a radially expanding sleeve, which is first inserted as Veress needle. Once in place, the needle is removed and a blunt trocar is inserted, which enlarges the sleeve and accommodates instruments up to 15 mm in diameter. It creates a smaller fascial defect than conventional trocars, potentially making fascial closure unnecessary and causing less postoperative wound pain. ^[19] However, Chiong et al reported an incidence of 0.66% of trocar-site hernia in patients without fascial closure after using 12-mm radially expanding trocars. ^[20]

Laparoscopes

Laparoscopes vary in size from 1.5 to 12 mm; the 5-mm and 10-mm laparoscopes are most commonly used in gynecology. The degree of the scope also varies; the most commonly used are 0-degree and 30-degree laparoscopes. The 0-degree laparoscope has the greatest application range because of the panoramic view it provides. However, the 30-degree laparoscope is often preferred in operative laparoscopy because it permits seeing anatomic structures better, especially during hysterectomy of a large uterus. The 45-degree laparoscope can also be used when dealing with a very large uterus.

An operative laparoscope has an integrated instrument channel through which an instrument can be passed and perform simple operative procedures through a single incision; the diameter of the channel varies from 5 to 7mm. These are usually 0-degree laparoscopes; they transmit lower light intensity and therefore a poor quality image. The operative scope is commonly used in laparoscopic sterilization using a Filshie clip applicator, tissue biopsy, and CO₂ laser procedures.

The Deflectible-Tip EndoEYE (Olympus) is a flexible laparoscope commonly used in single incision laparoscopic surgery. It has a deflectable tip which provides a 100-degree field of view, which is important in single incision surgery to avoid "sword fighting" of instruments, in which the close proximity of the instruments (see the image below) causes them to interfere with one another.

Patient Preparation

Anesthesia

Laparoscopy is routinely performed under general anesthesia. During laparoscopy, CO₂ gas is insufflated inside the peritoneal cavity, usually to a pressure of 15 mm Hg. This insufflation is necessary to optimize visualization. The increased intra-abdominal pressure has significant effects on the cardiovascular and respiratory systems. ^[21] The mean arterial pressure can be altered to create either hypertension or hypotension, depending on the intra-abdominal pressure. Cardiac arrhythmias can also occur.

The increased intra-abdominal pressure reduces lung volume, decreases pulmonary compliance, and increases peak airway pressures. The patient’s positioning in Trendelenburg position increases the risk of aspiration. This risk, along with increased intra-abdominal pressure and associated cardiovascular and respiratory changes, make regional anesthesia risky for most operative laparoscopy.

However, regional anesthesia has been described and used in laparoscopic preperitoneal inguinal hernia repair ^[22] and laparoscopic cholecystectomy. ^[23] Isobaric (gasless) laparoscopy does not affect the intra-abdominal pressure and may be ideally performed under regional anesthesia. ^{[24, 25]}

Positioning

For gynecologic cases, laparoscopy is typically performed while the patient is in low lithotomy position. This allows free access to the perineum and vagina to place a uterine manipulator to assist in lifting the uterus and visualizing the pelvic organs. Even in a patient who has previously undergone hysterectomy, placing the patient in lithotomy position allows access to the vagina and rectum to place a vaginal or rectal probe; this can help to identify pelvic structures, such as the vaginal cuff, the bladder, and the rectum. Lithotomy position also allows access to perform cystoscopy when needed to evaluate integrity of the bladder and ureters.

The patient's buttocks should be placed at the edge of the table or slightly over the edge. The arms should be tucked and well padded to provide more room for the surgeon. In operative laparoscopy, the surgeon tends to stand more cephalad; in single incision surgery, the surgeon stands almost at the level of the patient's head. Because most laparoscopic procedures are performed while the patient is in steep Trendelenburg position, padded straps may be used to prevent the patient from slipping cephalad. The patient is then placed in Allen stirrups, which should be well padded.

The patient’s thighs should be in the same plane as the body, hence the low lithotomy position. This will prevent the instruments from bumping into the patient's thigh and allows more space for the surgeon, especially when accessory trocars are placed low in the pelvis. The legs should be well supported and padded to prevent injury to the peroneal nerve. The hips should be minimally abducted and not more than 45 degrees. When access to the vagina is required, the thighs can be flexed (but not to more than 90 degrees) to avoid injury to the femoral, obturator, and sciatic nerves.

Prior to starting laparoscopic surgery, patients who are obese or have a history of chronic obstructive pulmonary disease are placed in steep Trendelenburg position to evaluate whether they can tolerate being in such a position. This step is crucial in robotic surgery because the patient cannot be moved out of position without undocking the robot (see the image below).

Obtaining Pneumoperitoneum

Once the patient is correctly positioned, prepped, and draped, a Foley catheter is inserted and (if needed) the uterine manipulator is placed. The next step of the surgery is obtaining the pneumoperitoneum. This step is critical because more than 50% of laparoscopic complications occur during this stage. ^{[26, 27]}

The surgeon has to first decide where to place the initial trocar. The initial trocar is used to obtain the pneumoperitoneum and to insert the laparoscope to initially survey the abdominal cavity. The most common sites to place the initial trocar are at the umbilicus, above the umbilicus in the midline, or in the left upper quadrant (Palmer’s point).

The image below shows recommended locations for trocar placement.

The video below shows a left upper quadrant entry technique.

The site depends on the surgery being performed and the suspected pathology. For example, when performing laparoscopic hysterectomy for a large bulky uterus or when extensive pelvic adhesions are suspected due to previous pelvic surgery, endometriosis, or pelvic inflammatory disease, the initial trocar is placed outside the pelvis, either above the umbilicus or at Palmer’s point (see the images below).

In the case of a large bulky uterus, placing the trocar at the umbilicus will cause suboptimal visualization of the pelvis due to the proximity of the uterine fundus to the scope.

For patients with previous pelvic surgery, endometriosis, or pelvic inflammatory disease, pelvic adhesions commonly involve the umbilicus and potentially increase risk of injury to the bowel or cause suboptimal visualization (see the images below). ^[28]  Madhvani et al found that among patients who underwent laparoscopic hysterectomy for benign disease, the presence of adhesions was associated with the greatest risk of major complications (adjusted odds ratio, 1.92). ^[29]

The next step is how to enter the abdomen. There are two general approaches: open and closed entry.

Technique for Open Entry

The open-entry technique was first described by Hasson in 1971. ^[30] This technique is typically performed at the umbilical site due to the proximity of the skin to the peritoneum.

The outer ring of the umbilicus is marked to prevent extending the incision beyond the umbilicus for better cosmesis. The skin incision can be made vertically through the umbilicus or in a semilunar fashion along the inferior margin of the umbilicus. The fascia is grasped with either Allis clamps or Baby Kocher clamps and entered sharply with Mayo scissors or scalpel.

The incision is extended vertically between 10 to 12 mm. Extending the fascia horizontally can risk injury to the rectus muscles and bleeding. The peritoneum is then identified and entered sharply with Metzenbaum scissors or bluntly with a fine-tip clamp (eg, tonsil clamp). Some surgeons prefer to tag the fascia and peritoneum for ease of closure at the end of the procedure. A Hasson trocar is then inserted and the abdominal cavity is insufflated. The Hasson trocar can then be secured to the previously placed suture tags or to sutures to the skin; some Hasson trocars have an intra-abdominal balloon that secures them in place (see the image below).

The open-entry technique is also used for single-incision laparoscopic surgery. However, due to the large size of the port used (see the image below), the fascia is transected vertically between 2.5 to 3 cm to allow the insertion of the port.

The skin does not need to be incised more than 1.5 cm due to its elasticity. Care must be taken to adequately reapproximate the fascia with either delayed absorbable or permanent sutures to prevent incisional hernia formation. In patients who are obese, smokers, or have chronic obstructive pulmonary disease or diabetes, permanent sutures are preferred due to poor wound healing, increased abdominal pressure, and probable increased risk of herniation.

The video below shows an open entry technique.

Technique for Closed Entry

The closed-entry technique is more commonly used. It employs a Veress needle, direct trocar entry without scope, or direct trocar entry with scope. The first two techniques are blind; direct trocar entry with scope is not.

The Veress needle can be used at any entry site; however, it is most commonly used for entry at the umbilicus or at Palmer’s point. Other less common sites include the uterine fundus ^[31] and posterior cul-de-sac. The major concern with using a blind technique is the risk of injury to major blood vessels and bowel. The major blood vessels at risk include the abdominal aorta, inferior vena cava, and common iliac vessels.

The relationship of the umbilicus to the underlying major vessels changes depending on the body mass index of the patient. Hurd et al ^[9] described this relationship using magnetic resonance imaging. They found that in patients with normal body mass index, the bifurcation of the aorta is immediately below the umbilicus, whereas in overweight and obese women, the bifurcation varies between 2 to 3 cm above the umbilicus.

We avoid midline blind entry techniques above the umbilicus to prevent injury to the underlying vessels. If the initial trocar needs to be placed above the umbilicus, then the Veress needle can be inserted at the umbilicus or at Palmer’s point to obtain the pneumoperitoneum and the trocar is subsequently introduced at the desired site. The created pneumoperitoneum increases the distance between the anterior peritoneum and the underlying major vessels, making the introduction of the initial trocar somewhat safer but not without risk. Preperitoneal insufflation can occur; this decreases the distance between the peritoneum and the underlying vessels and increases the risk of vascular injury. The pneumoperitoneum does not prevent injury to the adherent bowel.

Technique of Veress Needle Entry

When the Veress needle is used at the umbilicus, the skin incision is made equal to the size of the desired trocar. The patient should be in a flat neutral position (never in Trendelenburg position) and should be fully paralyzed with adequate neuromuscular blockade. ^[32]

The anterior abdominal wall is then grasped and elevated anteriorly to pull the abdominal wall away from the major vessels and bowel. In nonobese patients, the Veress needle is then placed at a 45-degree angle to the longitudinal axis of the patient and aimed towards the pelvis to avoid vascular injury. In obese patients, a 90-degree angle is preferred because the umbilicus is below the aortic bifurcation. See the image below.

Entering at 45 degrees in obese patients runs the risk of tracking into subcutaneous space. Also, placing the tip of the Veress needle at the base of the umbilicus decreases the risk of preperitoneal insufflations.

There are several steps to confirm correct intra-abdominal placement of the Veress needle. Teoh et al ^[33] tested four common techniques in 345 patients to verify Veress needle placement. The four tests are described in the table below.

Table. Most Common Tests Used To Ensure Correct Entry Using the Veress Needle (Open Table in a new window)

Teoh et al ^[33] found that the first three methods (double click, aspiration, and hanging drop) were not reliable. When the initial five gas pressure readings were all less than 10 mm Hg, there was never preperitoneal insufflation. They concluded that serial gas pressure measurement is the best indicator of correct placement (100% sensitive for preperitoneal insufflations).

Palmer’s Point Entry

Brill et al ^[34] reported the incidence of omental and bowel adhesions to the anterior abdominal wall in women after Pfannenstiel incision (27%), midline incision below the umbilicus (55%), and midline incision above the umbilicus (67%). The left upper quadrant site is usually free of adhesions and provides an exceptional panoramic view of the pelvis.

Prior to insertion of the trocar or Veress needle, a nasogastric or orogastric tube is placed to deflate the stomach. The Veress needle or trocar is inserted at Palmer’s point, which is 3 cm below the lowest rib in the left midclavicular line. ^[35] The angle should be at 45 degrees to abdominal wall. This site is considered somewhat safer due to absence of the major vessels (aorta, inferior vena cava, and iliacs) and requires less force to lift the anterior abdominal wall due to proximity of the rib cage, which is useful in obese patients.

Open Versus Closed Technique

Bonjer et al ^[6] compared the closed-entry technique in 489,335 patients to open entry in 12,444 patients and found that the rates of visceral and vascular injury were 0.083% and 0.075%, respectively, in closed entry versus 0.048% and 0%, respectively, with an open technique. This difference was statistically significant. The mortality rates after closed and open techniques were 0.003% and 0%, respectively. They concluded that open technique is safer.

In a Cochrane review, Ahmad et al demonstrated that open-entry technique had a reduced incidence of failed entry when compared with a closed-entry technique, but there was no difference in incidence of injury to viscera or vessels. When compared with Veress needle, the direct-entry technique had a reduced incidence of failed entry, extraperitoneal insufflation, and omental injury. The authors, however, acknowledge that the studies were limited by small numbers of patients and excluded patients with previous surgery and high body mass index. ^[36]

Closing 5-mm Incisions

Traditionally, the fascia is not closed when incisions are smaller than 10 mm, owing to the low risk of fascial dehiscence and bowel herniation. ^[37] However, cases reports describe bowel herniation through 5-mm trocars, and some authors recommend closure of all port sites. ^[38]

The author believes this might hypothetically occur because of excessive manipulation of the port or multiple port reinsertions, which might potentially make the incisions larger than 5 mm. Additionally, rapid deflation of the pneumoperitoneum while removing the port might create a suction effect, which might pull the omentum through the incision. However, closing all port sites might not be easily done in obese women unless the surgeon uses a fascial closing device (eg, Endo Close [Covidien] or Carter-Thomason CloseSure System [CooperSurgical])

To avoid this potential problem, the author recommends that all accessory trocars are removed under direct visualization before releasing the pneumoperitoneum, the fascial incision is explored though the scope to notice any bleeding or tissue shredding, and then the abdomen is deflated slowly through the umbilical site. The anterior abdominal wall is then gently pulled outward and gently shaken to release any omental adhesions to the accessory sites. Closing the 5-mm lateral trocar sites depends on whether the fascia is too thinned out, if bleeding or shredding (seen in older and obese women) occurred, or if extensive manipulation or multiple reinsertions of the accessory ports occurred during the procedure. However, the author routinely closes all midline port sites, especially at the umbilical site where the fascia and posterior sheet are commonly absent. For these sites, the author uses PDS #0, Prolene #0, or Vicryl #0 and tries to imbricate the medial aspect of the rectus sheet in the midline.