Principles of Laparoscopy



Principles of Laparoscopy


Megan Cesta

Resad Pasic

Meagan Slate

Ceana Nezhat



Introduction

Conventional video-assisted laparoscopy has challenged the notion that “bigger is better.” As surgeons develop novel techniques, using smaller incisions and less invasive approaches, the perspective has undoubtedly shifted to “less is more.” It has become clear that we, as surgeons, must continue to push the limits of ingenuity. The wealth of information available to both physicians and patients is remarkable but at times can lead to misguided information or unorthodox requests. Pleas for unconventional treatment often prove to be a blessing in disguise, leading to developments for new surgical techniques (single-site laparoscopy, transvaginal natural orifice transluminal endoscopic surgery [vNOTES]) and new technology. Despite this pivot toward a world of innovation and ingenuity, the beauty of laparoscopy lies in its simplicity of traditional surgical principles.

The most important concepts in laparoscopic surgery focus on two things: the machine and the driver; or better said, the skill of the surgeon and the availability of proper instrumentation. The equipment available in the operating room, or the machine, enhances the surgeon’s ability to perform the most complex of cases. This includes having the appropriate laparoscope, adequate pneumoperitoneum, and the correct choice of energy and dissection tool. The other, more important, component is the knowledge and skill of the surgeon. Although advancements in technology continue to evolve, the level to which a surgeon’s skill set is enriched by machinery is finite. Knowledge, training, experience, and creativity remain at the forefront of surgical success.

In order to fully understand the benefits of laparoscopic surgery, it is first necessary to review the annals of gynecologic surgery and its roots in the development of endoscopy. Over a century ago, in 1901, George Kelling performed the first endoscopy to examine the effects of pneumoperitoneum on dogs. Soon after, he performed the first human abdominal endoscopy, which he published in 1910.1 The first gynecologist to use laparoscopy was Karl Fervers who, in 1933, described his technique for lysis of adhesions. Soon after, in 1936, Swiss gynecologist, Boesch, performed a laparoscopic sterilization using electrocautery of the fallopian tubes. Raoul Palmer, a gynecologist at the Hôpital Broca in Paris, and his wife Elizabeth started to perform laparoscopic procedures in occupied Paris in 1943. In 1980, Hubert Manhes, from Clermont, France, published his laparoscopic approach to ectopic pregnancy.2 Either tubal aspiration or salpingostomy were used to treat 60 young women diagnosed with ectopic pregnancy; only three cases resulted in laparotomy.3

Kurt Semm is known as the father of modern pelviscopy, a term he coined to differentiate between gynecologic laparoscopy and procedures in the upper abdomen or liver. He was a German gynecologist with many inventions including an electronic carbon dioxide (CO2) insufflator, a uterine manipulator, and a tubal patency device.4 He performed the first laparoscopic appendectomy in 1981. It was the invention of video laparoscopy by Dr. Camran Nezhat in the early 1980s which proved to be the beginning of a surgical renaissance. He presented his technique at American Association of Gynecologic Laparoscopists (AAGL) in 1984 and American Society for Reproductive Medicine in 1985, and he published his experience describing the treatment of stage IV endometriosis with video-assisted laparoscopy.5 He proposed that with the application of this technique, the majority of laparotomies could be avoided. The major incentive for further advancement of laparoscopic procedures was the first total laparoscopic hysterectomy performed by Dr. Harry Reich in 1989. Dr. Kurt Semm performed the first laparoscopic supracervical hysterectomy which he referred to as the classic intrafascial supracervical hysterectomy in 1992.6 He described coring the cervix intrafascially without colpotomy and removing the transformation zone of the cervix as prophylaxis against cervical cancer. Introduction of laparoscopy into urogynecology started with Dr. Terry Vancaillie who performed the first laparoscopic modified Burch procedure. Camran Nezhat in the United States and Arnaud Wattiez in Europe were the first to perform the laparoscopic sacrocolpopexy.

When trainees are asked to describe the benefits of laparoscopic surgery, they often give a predictable response. The trainee describes the benefits of minimally invasive procedures with regard to the patient: less pain,
shorter recovery time, lower risk of infection, improved cosmetics, and shorter hospital stay. Although all of these factors remain relevant, it is important to remember the benefits to the surgeon. Video augmentation helps surgeons, as one who can see better can do better. In a traditional laparotomy, as the surgeon advances deeper into the pelvis, visualization declines and views of the pelvic structures become diminished. This shortcoming is bypassed with video-assisted laparoscopy. Maintaining the assistant’s focus or sharing information with the operating room staff, simply by directing the camera to the task at hand, is a benefit not observed in traditional laparotomy. The laparoscopic surgeon can maintain the same visual distance between the camera and the target organs throughout the case. This provides better ergonomic maneuverability during extensive pelvic dissections. With video laparoscopy, compared with conventional laparoscopy, the entire surgical team is watching the procedure, and can therefore predict the needs of the surgeon. This allows for better preparation and shorter operating times, which benefit both the patient and the surgeon.

The training and technique of the laparoscopic surgeon stems from the belief that knowledge is power. The expert surgeon spends equal amounts of time out of the operating room: preparing for the case, honing their skills, and anticipating any complications that may arise. As visualization during laparoscopy continues to improve, the understanding of pelvic anatomy has blossomed. Structures such as the hypogastric nerve plexus, avascular planes in the space of Retzius, knowledge of embryonic variants, and deviations of the ureteral pathways are key to safe dissection.

It is important to select the appropriate patient for minimally invasive surgery. Relative contraindications to laparoscopic surgery include hemodynamic instability, inability to tolerate pneumoperitoneum, and some of the known metastatic diseases. An unstable patient presenting with hemoperitoneum was previously considered a contraindication to laparoscopy. Over the last decades, though, a palpable shift was noted in residency programs, with particular attention being placed on laparoscopic training. This has resulted in enhanced teaching and surgical experience, and as a result, many young gynecologic surgeons feel comfortable addressing gynecologic emergencies, such as a ruptured ectopic pregnancy or ovarian torsion, using a minimally invasive approach.

The physician must understand the physiologic variations observed in laparoscopic surgery. These focus mainly on respiratory and cardiovascular changes which may restrict adequate Trendelenburg positioning, limit visualization, or create an operative field with inadequate pneumoperitoneum. This is less of a concern in young, healthy patients but can be surgically prohibitive in patients with a history of cardiovascular or pulmonary compromise. Absorption of CO2 into the systemic circulation can result in hypercarbia, metabolic acidosis, and subsequent changes in myocardial contractility. Intra-abdominal pressure is typically limited to 12 to 15 mm Hg, with an upper threshold of 25 mm Hg. Elevated intra-abdominal pressure compresses the inferior vena cava, resulting in decreased preload and subsequent decrease in cardiac output. Suboptimal oxygenation occurs as a result of the upwardly displaced diaphragm and reduced lung volume observed with a combined pneumoperitoneum and the Trendelenburg position (Fig. 21.1). Also, a temporary decline of urine production is to be expected. This is due to a combination of decreased cardiac output, increased release of renin and antidiuretic hormone, and direct renal compression. Renal function should return to normal after surgery and have no lingering effects.






Prior to the incision, it is the responsibility of the surgeon to ensure that the patient, the operating room, the staff, and the equipment is prepared for the procedure in their respective ways. The patient should be an active participant in preparing for the procedure as well as in the recovery process. Enhanced recovery after surgery actually begins preoperatively, by reviewing expectations and discussing the importance of optimizing a patient’s health prior to the procedure. This should begin in the office, where there is sufficient time to discuss weight loss goals, exercise routines, tactics for smoking cessation, and initiation of medications to improve underlying medical conditions.7 On the morning of surgery, the operating room staff should ensure that the room is cleaned and stocked, with all instruments in working order. Important steps, such as operating room organization, instrument setup, and proper patient positioning, are often overlooked. A team approach to ensure the safest possible environment must be used.

Setting the surgical team up for success starts with a well-thought-out operating room configuration. Laparoscopic instrument movement is limited to fixed ports through the fascia; therefore, proper planning
must occur prior to the procedure beginning. Ideally, the operating table is in the center of the room with surgical lighting directly above. Table mechanics should be in working order to allow for quick adjustments and graduated Trendelenburg position. Special considerations may be necessary for bariatric patients. Video monitors should be positioned directly in front of the surgeon and the assistant, 10 to 20 degrees below eye level to limit neck strain. The table height should be adjusted to maximize the surgeon’s comfort and ergonomics as well as reduce operative fatigue (Fig. 21.2). The video monitor tower is positioned opposite of the primary surgeon to provide an unobstructed view of the equipment display panels. Foot pedals are placed comfortably within reach, allowing the surgeon to use energy without removing his or her eyes from the video monitor.







PATIENT POSITIONING

Correct patient positioning is crucial to performing successful laparoscopy. Incorrect positioning can lead to complications such as nerve injury and compartment syndrome. The symptoms present as burning, numbness, and weakness depending on the specific nerve damage, and the deficit is almost always present immediately after surgery. Injury resulting from improper positioning typically occurs from the following common mechanisms: ischemia, stretching, and compression. Common risk factors for injury include low and high body mass index (BMI), immobility, and long operative times.8 Other surgical factors such as incision type and use of retractors can also lead to nerve injury through various mechanisms. Trocar placement during laparoscopy can injure the ilioinguinal and iliohypogastric nerves. This chapter focuses on nerve injury resulting from surgical positioning.






The patient should be placed caudal on the operating bed to allow vulvar and vaginal access during surgery. The sacrum must be well supported by the operating table. Once positioned appropriately on the table, the patient’s arms should be tucked when performing laparoscopy to avoid brachial nerve injury. The brachial plexus arises from the anterior nerve roots of C5-T1. Upper root injury can cause Erb’s palsy, whereas lower root injury to C8-T1 will cause Klumpke paralysis. Padding along the medial epicondyle of the arm protects the ulnar nerve, as it is most vulnerable in this location (Fig. 21.3). Care should be taken to wrap or pad any hard surfaces or potential pressure points along any intravenous lines that may rest against the patient. The arms should be placed at the patient’s side in a neutral position with the thumb facing up and properly padded. The arms should not be pronated or supinated while tucked. The shoulders should be neutral and pressure points such as the acromioclavicular joint should be padded.9 Shoulder braces may be placed laterally. However, if placed improperly, it can cause compression of the brachial plexus along the neck.

Next, the legs are positioned in stirrups for laparoscopy. There are different weight tolerances for boots, and the correct weight should be selected based on the patient. Positioning the legs may also be done while the patient is awake to ensure comfort and correct placement. The hip flexors must be positioned with slight flexion to avoid femoral and sciatic compressions and extensions (Fig. 21.4). Flexion should be limited to no more than 90 degrees, and abduction of the hip should not exceed more than 45 degrees. Incorrect placement at this point could lead to lateral femoral cutaneous or obturator nerve injury. Knees must be flexed between 90 and 120 degrees with care taken to ensure the heel is placed firmly and remains in contact with the boot. If the heel is not seated correctly
in the boot, the weight of the calf may rest on the top of the boot, creating a pressure point on the common peroneal nerve as it courses along the posterior leg. In extreme cases, compartment syndrome can result from concomitant vascular compression. This can present a challenge when positioning the morbidly obese patient. The surgeon should allow for additional padding to be placed at potential pressure points (Fig. 21.5). The foot should not be dorsiflexed or plantar flexed but should rest evenly on the boot surface. Attention should also be directed at avoiding any compression of the peroneal nerve at the lateral fibular head, which may come in close proximity to the lateral portion of the booted stirrup (Fig. 21.6). Candy cane stirrups should not be used during laparoscopy.






There are many assistive devices when positioning a patient to prevent sliding in the Trendelenburg position. Sliding cephalad on the operating table can lead to patient injury and reduce vaginal access during surgery.10 Many gynecologic surgeries require steep Trendelenburg and thus patients are at increased risk for slipping. Patients can be placed on a specially designed nonslip foam pad or a gel pad to reduce the amount of weight placed on pressure points.11 Beanbag systems are commonly used, especially in robotic-assisted laparoscopic surgery (Fig. 21.7). There are also foam restraint systems that may be placed around the neck and shoulders to maintain proper shoulder positioning and minimize risk of brachial plexus injury. Additionally, consider leveling the patient from Trendelenburg or steep Trendelenburg every 3 hours during surgery to decrease risk of neuropathy resulting from positioning.






The surgeon must also be aware of external forces on the patient that can lead to nerve injury or facial edema. Surgical team members should avoid resting their weight, or placing any instruments, on the patient or the stirrups. Instruments should be kept in established drape pockets or on the surgical instrument table. They should not rest freely on the patient when not in use. Finally, the patient should be continuously monitored during surgery for equipment failure or slippage that may require repositioning.













ABDOMINAL ENTRY AND ESTABLISHING PNEUMOPERITONEUM


Site of Entry

There are many options for site of entry in laparoscopy with several key factors playing into the decision-making process, such as the patient’s surgical history, body habitus, and the surgeons’ experience. No single entry site method is proven to be safer than another.12 Preparation is required in laparoscopy before establishing the pneumoperitoneum. Pneumoperitoneum is rarely contraindicated but should be avoided in patients with closed-angle glaucoma or elevated intracranial pressure. Intra-abdominal pressure rise is accompanied by an intracranial and intraocular pressure rise, both of which are increased by the Trendelenburg position.13,14 For gynecologic surgery, the patient must be positioned in the dorsal lithotomy position. A Foley catheter should be placed to drain the bladder and the surgical table must be leveled. An orogastric tube should be placed, especially if the site of entry is in the left upper quadrant (Palmer’s point).

The umbilicus is a common site for laparoscopic entry. It is the thinnest point of the abdomen, providing a short distance for the trocar to course before entering the abdomen. All entry techniques can be used at this site. The umbilicus is typically located at the T10 dermatome level. The aorta bifurcates just caudally to this point, near the L4 level. Extremes of BMI can alter the usual location of the umbilicus. Obesity, or extreme weight loss, may displace the umbilicus caudally. Therefore, instead of the recommended 45-degree angle of entry, a 90-degree angle is permissible given that the aortic bifurcation is further away. Prior abdominoplasty can also alter the true location of the umbilicus. When entering at the umbilicus, the surgical table must be level. Placing a patient in Trendelenburg position will bring the umbilicus and the aortic bifurcation closer together, putting them at higher risk for vascular injury. The right common iliac vein is the most commonly injured vessel during umbilical entry. Trocar entry at a 45-degree angle is usually performed in patients with low or normal BMI but may lead to preperitoneal insufflation (Fig. 21.8).15 Abdominal wall elevation with towel clips or lap cap allows a 90-degree entry, minimizing this risk.

Difficulty entering at the umbilicus can be caused by adhesions from previous surgery, most commonly seen with prior midline vertical laparotomy incision, or in patients who have abdominal mesh. Complications of umbilical entry include injury to bowel and large vessels. Preoperative periumbilical ultrasound-guided saline infusion (PUGSI) is a quick and effective way to diagnose subumbilical adhesions preoperatively. This technique involves tenting the abdominal wall with towel clamps and passing a sterile 19G needle into the peritoneal cavity. Water is then injected, under transabdominal ultrasound monitoring, and fluid loculation indicates the presence of umbilical adhesions (Video 21.1). A positive test would indicate to the surgeon that an alternative port entry site is preferable.16

Another common site of laparoscopic entry is Palmer’s point. Initially described by Raoul Palmer in the 1970s, the point is located in the left midclavicular line, 2 fingerbreadths below the inferior costal margin (Fig. 21.9). Potential complications of entry at this site include stomach, spleen, liver, or bowel injury. An alternative to Palmer’s entry is recommended if the patient has had gastroesophageal surgery or splenectomy. Palmer’s is a popular choice for entry if the patient has had previous laparotomies or is pregnant. Although this site of entry is located far from the pelvis with normal pathology, it can be useful in cases with suspected adhesions, enlarged uteri, or ovarian pathology. Multiple entry techniques can be used at this point such as closed entry or direct vision entry.12

The right subcostal margin has also been described as a point of entry. It important for the surgeon to note
that the liver and bowel are in close proximity. The subxiphoid region known as the Lee-Huang point, located between the xiphoid and umbilicus point, can also be used. It is imperative that the table be leveled if this entry technique is used.17 Transuterine insufflation may be helpful in patients who are obese.18 Finally, the ninth intercostal space may be used as well.












Entry Technique

Closed entry by Veress needle insertion is the most common technique used by gynecologists (Fig. 21.10). The needle is used at the umbilicus or in Palmer’s point entries. The base of the umbilicus is the thinnest point in the abdomen as there is no muscle or fat between the umbilicus and peritoneum. The Veress needle is punctured through two layers of tissue and the audible click or retraction of the needle tip reinforces that the needle is placed in the correct plane. At the Palmer’s point, the Veress enters three tissue planes, and three audible clicks are heard and felt. The three planes here are the aponeuroses of the external and internal oblique, the aponeuroses of the internal oblique and transversus abdominis, and the peritoneum (Video 21.2). To ensure the needle is in the correct plane, the insufflation is connected to the Veress needle and opening pressures below 10 mm Hg usually is an indication of entrance into the intraperitoneal space. If higher pressures are encountered, the Veress needle should be slightly pulled back to make sure that the tip of the needle is not blocked by the omentum. A syringe with the depressor removed may be filled with normal saline and placed on the Veress needle to perform the “water drop” test. If water flows freely, the needle is presumed to be intraperitoneal. False-positive tests can occur if water flows freely into the preperitoneal space. A trocar is then inserted blindly until no resistance is felt or under direct visual entry.

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May 1, 2023 | Posted by in GYNECOLOGY | Comments Off on Principles of Laparoscopy
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