Basic Laparoscopy





Laparoscopic surgery is a minimally invasive technique where surgery is performed inside the abdomen using endoscopic cameras, small-diameter instruments, and access ports all through small incisions in a gas-distended environment. The advantages of laparoscopic compared to open surgery include reduced blood loss, decreased postoperative pain and need for narcotics, improved cosmesis, and shorter hospital stay and convalescence period. For abdominal and pelvic surgery, the most common approach is transperitoneal; however, laparoscopic surgery can also be performed while staying outside the abdominal cavity in an extraperitoneal or retroperitoneal approach. Laparoscopic surgery can also be performed with devices allowing a hand to be inserted for assistance, which will be reviewed here. Laparo-endoscopic single-site surgery (LESS) and natural orifice translumenal endoscopic surgery (NOTES) are more advanced laparoscopic techniques to reduce invasiveness even further and will not be discussed in this chapter. This chapter will focus on the basics of laparoscopic surgery.


Patient Selection


While laparoscopic surgery has many advantages over open approaches, not all cases are suitable for laparoscopy. Contraindications to laparoscopic surgery are related to patient comorbidities, body habitus, and disease characteristics. Patients with significant cardiopulmonary disease are at increased risks for hypercarbia and metabolic acidosis. Other patient-specific factors including morbid obesity, extensive prior abdominal surgery, large aneurysms, and large abdominal wall hernias are relative contraindications to laparoscopic surgery. In these cases, an extraperitoneal approach may allow for a minimally invasive approach while avoiding surgery in a potentially hostile abdomen. Disease-specific factors such as large masses, advanced intraabdominal malignancy, large-volume hemoperitoneum, and significant bowel distension may limit the working space for laparoscopic surgery, and patients with these characteristics may best be served with an open surgery. When a laparoscopic approach has been selected, the patient should be counseled that there is always the possibility of converting to an “open” or larger incision approach if the planned procedure cannot be safely and effectively performed.




Monitoring Equipment


For urologic laparoscopic procedures, general anesthesia with standard anesthetic approaches and monitoring are utilized. In addition, capnography is used to follow carbon dioxide elimination. In longer cases, blood samples can be obtained to analyze blood gases and metabolic status. The anesthesia staff may elect to place an arterial line at the beginning of the procedure based on the patient’s medical comorbidities and procedure.




Instrumentation


Technological advances have resulted in more sophisticated laparoscopic instruments. Basic laparoscopic surgery requires an insufflator to establish pneumoperitoneum, an imaging system, light source, and a video monitor. Trocars, grasping instruments, cutting and energy dissectors, needle drivers, retractors, clips, staplers, balloon dilators, suction irrigators, and entrapment bags for specimen removal are instruments commonly used in laparoscopic surgery and will be reviewed further. Instrument specifications should be reviewed by the surgeon prior to use to ensure a thorough understanding of their correct usage, capabilities, and limitations. Additionally, instruments for laparotomy should always be available to the operating room in case there is need for emergent conversion to open.


Insufflators


Insufflating the surgical cavity with gas to create a distended working space between the wall structures and the internal organs facilitates laparoscopic surgery. The gas most commonly used as an insufflant is carbon dioxide. Conventional insufflator systems work by connecting a trocar to a carbon dioxide tank and instilling filtered and warmed carbon dioxide gas for a goal pressure of 12–15 mm Hg in adults. Distensive gas pressure loss can occur with suction and smoke evacuation and result in collapse of the working space. For complex procedures, some authors advocate using two separate insufflation systems simultaneously or the new AirSeal system. AirSeal is a specialized monitoring and insufflation system. Some literature studies have found shortened operative times and improved outcomes.


Imaging System


The imaging chain is a complex system and consists of image capture via lens or video chip, video processing, and display. A huge variety of commercial system options exist and are rapidly incorporating many of the advances in optical technology and video. High-definition systems along with some systems incorporating three-dimensional display are available. Historically, a fiberoptic rod lens scope consisting of either a 5- and 10-mm rod lens with associated light-carrying bundles with a 0-, 30-, or 70-degree lens angulation were used with attached cameras. Smaller, microlaparoscopic (less than 3.5 mm) systems are available but may sacrifice the amount of light bundles and resultant picture quality. New technologies incorporating scopes with adjustable flexible tip to adjust angulation by the camera operator (Endoeye Flex 3D Olympus) or rigid scopes with an adjustable distal angulation of the lens (Endo Chameleon, Storz) are being used by some surgeons. Displays are also advancing with changes in the video industry including High Definition (HD), chip technology (CMOS, etc.), 3D technology, and other types of new imaging including fluorescent technologies. Integrated systems that allow for multiple displays, picture in picture (PIP), recording, and specialized adjustments are available from a variety of manufacturers. Simple maneuvers, such as devices to warm and clean scopes as well as devices to clean condensation from trocars, are key to optimize visualization.


Trocars


The vast majority of surgeons use trocars or ports in laparoscopy to pass the camera and instruments into the operative field. Trocars basically consist of a hollow tube with some type of external seal to prevent gas leakage. They typically have an obturator that fits within the tube and facilitate entry with either a sharp or dilating tip. Trocars come in a variety of configurations and constructions, both disposable and reusable. Reusable trocars are typically constructed of metal with rubber seals that are replaceable and cleanable to reduce cost. Modern disposable trocars facilitate abdominal wall entry with features such as clear shafts, blunt or dilating tips, and optimized sealing systems. Blunt-tip trocars allow for separation rather than division of muscle fibers and have a decreased risk for port site hernia formation. For standard laparoscopy, trocar diameters range from 5 to 12 mm. Size selection depends on the type and size of the instruments that will be used during the procedure. Other variations in trocar design include optical trocars, which have clear plastic at the end and allow the scope to be placed within to visualize the wall layers during insertion. Some trocars have an anchoring device and fixation portion to create a seal, which is necessary when a Hasson or open techniques are used to access the abdominal cavity. Many trocars have a stopcock to connect to insufflation tubing. Trocars also come in a variety of lengths to accommodate various body habitus. When performing minilaparoscopic surgery, trocars ≤3.5 mm in diameter are used.


Instruments


Generalized


A variety of instruments are available for laparoscopic surgery and many times are specialized based on desired tasks or manufacturers. The typical instrument consists of a shaft of varying length, a control handle, and an end effector. Specialized long instruments are available for obese patients or situations that require extended reach. Historically, laparoscopic instruments were hand controlled and capable of only limited degrees of freedom requiring extensive learning for advanced manipulation such as suturing. More recently, a variety of instruments and manufacturers have desired incorporating advanced manipulative ability, including articulation and extra degrees of freedom to allow for advanced procedures and in response to robotics.


Grasping Instruments


A variety of graspers and jaw configurations, based on desired tissue effects and properties, are available for use during laparoscopy. Grasper jaws are generally able to rotate using a knob near the handle. There are traumatic and atraumatic graspers. The tips can be straight, curved, wide-based, or pinpoint, depending on dissection and tissue properties. Instruments can have locking handles, which can facilitate their use as retractors as well. Graspers with fenestrated or specially designed or treated jaw surfaces are also available and provide superior grasping ability for some tissues.


Needle Drivers


Needle drivers should always be used when handling a needle laparoscopically, suturing, and tying knots. Various jaw configurations and handle types are available for laparoscopic needle drivers including palm grip, pistol grip, and finger grip. There is variability in the unlocking mechanisms among laparoscopic needle drivers. The surgeon undertaking laparoscopic suturing should become facile and comfortable with needle drivers at their institution. A variety of researchers and manufacturers are exploring new technology to aid with the challenging task of laparoscopic suturing.


Retractors


Ongoing stable and atraumatic retraction with either adjustable or set-position retractors is a necessity for a variety of urologic laparoscopic procedures. During laparoscopic urologic surgery, retractors are most commonly used for right-sided surgery to keep the liver out of the operative field. There are many types of retractors; several of the most commonly used are described here. For liver retraction, a locking grasper may be inserted through a trocar below the xiphoid process with its jaws grasping the right abdominal side-wall. The Nathanson retractor is an angulated bar-type retractor that is inserted through a small skin incision without a trocar and is typically held in place with a table-mounted instrument-holding arm. There are also articulating retractors that are inserted as a flexible snake-type rod and form a triangle or circle when the actuation knob on the handle is turned. This type of retractor can also be supported in a fixed position with a table-mounted device. A fan retractor has several flat blunt blades that open into a fan shape and can hold back a wide area. Surgeons can often utilize adjustments of the table and patient positioning to allow for “gravitational” retraction of organs and viscera.


Scissors


Laparoscopic scissors can be used to perform both tissue dissection and to cut sutures. A variety of sizes, blades, and configurations are available. Reusable, fully disposable, or reposable (replaceable blades and/or shaft) scissors are available.


Energy Dissectors/Tissue Sealers


Various energy dissectors are available and come in various forms including grasping jaws and hooks. Monopolar and bipolar energy instruments are available. These can be used for dissection, cauterization, vessel sealing, and dividing tissue. Surgeons should be familiar with the advantages and disadvantages of monopolar and bipolar energy. Tissue dissection/sealing devices are available from a variety of commercial manufacturers. Such devices attempt to combine sealing of vascular structures and tissues with dissection and cutting to optimize hemostasis, improve dissection, and potentially reduce operative time and costs along with instrument exchanges.


Clips


Clips are occlusive and standardly used for securing blood vessels and tissues for hemostasis or closure. Clips may also be used for retraction, holding structures together, fastening mesh in place, and in place of a knot to secure a suture. Single-load clips and reusable appliers are typically less expensive; however, multiple clip preloaded appliers save time, especially for operations involving numerous vessels or clip application.


Staplers


Laparoscopic staplers are available with a variety of features from various manufacturers. Modern devices allow for precise placement including articulation and rotation of the blades. Staplers are also available in manual and powered actuation control versions. Most staplers cut as well as staple. Staple loads come in different lengths, staple heights, and number of staple rows. Most commonly, they come with six rows of staples and divide the tissue between rows three and four. Typically, shorter staple height is used for vascular structures. It is imperative to ensure the staple load is loaded and seated correctly in the stapler and the device is used correctly to prevent complications such as major bleeding and morbidity. Care should be taken not to fire staples over previously placed clips or staples to prevent malfunction. Stapling devices are used most commonly in urology to ligate large vessels (renal vessel ligation), ligate and divide large tissue bundles, or to perform bowel anastomoses for urinary diversion and bowel segment incorporation into the urinary tract. The surgeon should become intimately familiar with the optimal stapler load for the desired tissue characteristics and operation of the stapler.


Suction Irrigation


With a combined suction/irrigation system, the suction/aspiration channel is connected to the operating room vacuum system with an intervening fluid capturing container and the irrigation channel to a sterile saline or water container. Suction is used to clear the surgical field of blood, other bodily fluid, irrigant, and smoke from cautery. Irrigation can clear obscuring blood, debris, or fluid from the field allowing optimal visualization


Entrapment Bags


During extirpative procedures, particularly for oncologic cases, an entrapment bag is used. Entrapment bags come in a variety of sizes and materials, some of which resist tearing and leakage. The mode of deployment varies by manufacturer. The retrieval string of the sack is delivered through the extraction site. To remove the specimen, especially if it is large, a port-site incision can be extended or a separate muscle-splitting extraction incision (such as a cosmetically preferable Pfannenstiel incision) is made.


Manual morcellation of noncancerous specimens within special tear-resistant bags is used by some surgeons to keep the extraction site incision small and reduce invasiveness.


Morcellators


If morcellation is desired, the contents may be manually fragmented with ring forceps while the specimen is within an entrapment bag. Morcellation in our practice is only used if benign disease is suspected. Some commercial mechanical morcellators in other specialties have been criticized because of the rare but devastating complications of cancer seeding, inadvertent abdominal organ injury, or vascular injury associated with use of the morcellator.


Balloon Dilators


Balloon dilators can be used to facilitate an extraperitoneal approach to the bladder, prostate, and kidney. Commercially available dilating balloons come in a variety of shapes, including spheroid or oblong shaped, and often have a clear trocar, which allows for visualization during the dilatation/balloon dissection procedure. Some authors have described constructing dilatation balloons on the field out of varied sterile surgical equipment including gloves and catheters in order to reduce cost.


Ultrasound


Laparoscopic ultrasound devices are available for intraoperative imaging and allow for extremely good visualization as the ultrasound is placed directly onto the organ such as the kidney. Use of intraoperative ultrasound imaging is growing with utilization at the time of partial nephrectomy to aid in defining margins and aiding in structural identification. Probes are available both as a laparoscopic surgeon-controlled instrument or as a drop-in probe that can be manipulated by the robot or a laparoscopic instrument.




Preparation


Informed Consent


Informed consent is a key to all surgical procedures and consists of a dialogue between surgeon and patient defining the current diagnosis, benefits, risks, and alternatives of the procedure. Additional risks specific to a laparoscopic approach include gas embolism, hypercarbia, and pneumothorax. The patient should always be informed of the possibility of converting to an open or larger incision operation due to intraoperative findings, bleeding, surrounding organ damage, lack of progression, or the surgeon’s judgment that the procedure will be safer. Conversion to an open approach should not be viewed or construed as a complication.


Mechanical Bowel Preparation


Mechanical bowel preparation may be omitted prior to laparoscopic procedures not involving the bowel as recent series on laparoscopic prostate and kidney surgeries did not show any benefit. Even when small bowel is used for reconstruction of the urinary tract, a mechanical bowel preparation has been found to be unnecessary, though bowel preparation when colon is being used is still recommended.


Laboratory Tests


A type and screen (or type and cross-match for difficult cases) is typically obtained in case of hemorrhage. We obtain a starting hemoglobin/hematocrit with a complete blood count, which also evaluates for thrombocytopenia. A basic metabolic panel is often necessary to assess preoperative renal function and to dose medications appropriately. If there is concern for bleeding diathesis, a coagulation panel should be obtained. If the urinary tract is to be entered, then a urine culture should be sent and treated appropriately for the clinical scenario.


Antibiotic Prophylaxis


The AUA guidelines have provided specific recommendations for antimicrobial prophylaxis for all urologic procedures. The guidelines recommend that all patients undergoing laparoscopic urologic surgery without entry into the urinary tract should receive a first-generation cephalosporin or clindamycin if they are allergic to cephalosporins prior to surgical instrumentation. If entry into the urinary tract is expected, then a first- or second-generation cephalosporin, or an aminoglycoside with flagyl or clindamycin may be administered. Alternative acceptable antibiotic regiments if these cannot be given include ampicillin/sulbactam or a fluoroquinolone. If the intestines will be entered then patients should receive a second- or third-generation cephalosporin, or an aminoglycoside plus flagyl or clindamycin. Alternative acceptable antibiotic regiments if these cannot be given include ampicillin/sulbactam, ticarcillin/clavulanate, pipercillin/tazobactam, or a fluoroquinolone. For colon surgery, bowel preparation with oral neomycin and either erythromycin or metronidazole can be added to or substituted for systemic agents. Alternatively, if your hospital has an antibiotic stewardship program then any specific prophylaxis recommendations they have made should be followed, as they likely take into account microbial resistance patterns specific to your patient population.


Deep Venous Thrombosis Prophylaxis


Pneumoperitoneum may lead to venous stasis and increase risks of deep venous thrombosis (DVT). Sequential compression devices should be applied to the patient’s lower extremities before induction of anesthesia to reduce the risk of developing a DVT. Subcutaneous heparin may also be given perioperatively.


Anesthesia


Use of general endotracheal anesthesia is recommended for laparoscopic procedures because the pneumoperitoneum can limit the expansion of the diaphragm, respiration, and ultimately oxygenation. Adequate abdominal and diaphragmatic relaxation is mandatory. Routine patient monitoring includes continuous electrocardiogram monitoring, intermittent noninvasive blood pressure monitoring, pulse oximetry, temperature, and end-tidal carbon dioxide. The anesthesia team should monitor carbon dioxide absorption and potential for metabolic disarray closely, especially for patients with underlying metabolic issues such as renal failure.




Patient Positioning and Preparation


The specific positioning of the patient is determined by the procedure being performed. Careful attention to padding and securing the patient is performed to avoid nerve or soft tissue injury. This is especially important during long procedures and for procedures on obese patients, wherein such complications, including the risk of rhabdomyolysis, are more likely. Insertion of an oral gastric tube or nasogastric tube into the stomach and a Foley catheter into the bladder decompresses these organs and minimizes risk of injury. Shave and prepare the operative field widely with standard prep solutions. Drape the patient to leave the genitalia exposed if indicated. We typically plan and mark where an open incision will be made in case there is an emergent need to convert to an open operation.


Bed Manipulation


During the procedure, manipulation of the contents of the operative field via gravity is a key technique for exposure. The patient must be secured well to the bed during the preparatory phase of the procedure. The bed and patient can then be manipulated to position the viscera and organs. Examples of manipulation include Trendelenburg, reverse Trendelenburg, and airplaning. Such maneuvers are often valuable in moving viscera such as the intestines away from the field. Additionally, such maneuvers can aid exposure to the work area, such as using reverse Trendelenburg to gain exposure above the adrenal. The bed may also be airplaned to the right or left. Thus it is imperative that the patient be completely secured to the table with appropriate straps and tape to prevent a fall.

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Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Basic Laparoscopy
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