Instruments Prof. Dr. R. K. Mishra INSUFFLATION SYSTEM Laproflattor The electronic carbon dioxide (CO 2) laproflattor is a general-purpose insufflation unit for use in laparoscopic examinations and operations (Fig. 1). Controlled pressure insufflation of the peritoneal cavity is used to achieve the necessary work space for laparoscopic surgery by distending the anterolateral abdominal wall and depressing the hollow organs and soft tissues. CO2 is the preferred gas because it does not support combustion. It is very soluble which reduces the risk of gas embolism, and is cheap. Automatic insufflators allow the surgeon to preset the insufflating pressure, and the device supplies gas until the required intra-abdominal pressure (IAP) is reached. The insufflator activates and delivers gas automatically when the IAP falls because of gas escape or leakage from the ports. The required values for pressure and flow can be obtained using jog keys and digital displays. Insufflation pressure can be continuously varied from 0 to 30 mm Hg; total gas flow rate and volumes can be set to any value in the range 0–45 L/min. Patient safety is ensured by optical and acoustic alarms as well as several mutually independent safety circuits. The detail function and quadromanometric indicators of insufflator is important to understand safety point of view. The important indicators of insufflators are preset pressure, actual pressure, flow rate, and total gas used. Quadromanometric Indicators Quadromanometric indicators are the four important readings of insufflator. The insufflator is used to monitor: 1. Preset insufflation pressure 2. Actual pressure 3. Gas flow rate 4. Volume of gas consumed Preset Insufflation Pressure This is the pressure adjusted by surgeon before starting insufflation. This is the command given by surgeon to insufflator to keep IAP at this level. The preset pressure ideally should be 12–15 mm Hg. In any circumstance, it should not be more than 18 mm Hg in laparoscopic surgery. However, in extraperitoneal surgery preset pressure can be more than 18 mm Hg. The good quality microprocessor-controlled insufflator always keeps IAP at preset pressure. Whenever IAP decreases due to leak of gas outside, insufflator eject some gas inside to maintain the pressure equal to preset pressure and if IAP increases due to external pressure, insufflator sucks some gas from abdominal cavity to again maintain the pressure to preset pressure. When surgeon or gynecologist wants to perform diagnostic laparoscopy under local anesthesia, the preset pressure should be set to 8 mm Hg. In some special situation of axilloscopy or arthroscopy, we need to have pressure >19 mm Hg. Actual Pressure Fig. 1: Insufflator. This is the actual IAP sensed by insufflator. When Veress needle is attached, there is some error in actual pressure reading because of resistance of flow of gas through small caliber of Veress needle. Since continuous flow of insufflating gas through Veress needle usually gives extra 4–8 mm Hg of measured pressure by insufflator, the true IAP can actually be determined by switching the flow from insufflator off for a moment. Many microprocessor-controlled good quality insufflator delivers pulsatile flow of gas when Veress needle is connected, in which the low reading of actual pressure measures the true IAP.
If there is any major gas leak, actual pressure will be less and insufflator will try to maintain the pressure by ejecting gas through its full capacity. Actual pressure if >20–25 mm Hg has following disadvantage over hemodynamic status of patient: ■ Decrease venous return due to vena caval compression leading to: z Increased chance of deep vein thrombosis (DVT) of calf z Hidden cardiac ischemia can precipitate due to decrease cardiac output ■ Decrease tidal volume due to diaphragmatic excursion ■ Increase risk of air embolism due to venous intravasation ■ Increased risk of surgical emphysema ■ Decreased renal perfusion. Flow Rate This reflects the rate of flow of CO2 though the tubing of insufflator. When Veress needle is attached, the flow rate should be adjusted for 1 L/min. Experiment was performed over animal in which direct intravenous (IV) CO 2 was administered and it was found that risk of air embolism is less if rate is within 1 L/min. At the time of access using Veress needle technique, sometime Veress needle may be inadvertently enter inside a vessel but if the flow rate is 1 L/min there is less chance of serious complication. When initial pneumoperitoneum is achieved and cannula is inside abdominal cavity, the insufflators flow rate may be set at maximum, to compensate loss of CO2 due to use of suction irrigation instrument. This should be remembered that if insufflator is set to its maximum flow rate then also it will allow flow only if the actual pressure is less than preset pressure otherwise it will not pump any gas. Some surgeon keeps initial flow rate with Veress needle to 1 L/min and as soon as they confirm that gas is going satisfactorily inside the abdominal cavity (percussion examination and seeing obliteration of liver dullness) then they increases flow rate. No matter how much flow rate you set for Veress needle, the eye of normal caliber Veress needle can give way CO2 flow at maximum 2.5 L/min. When the flow of CO2 is >7 L/min inside the abdominal cavity through cannula, there is always a risk of hypothermia to patient. To avoid hypothermia in all modern microprocessor-controlled laproflattor, there is electronic heating system which maintains the temperature of CO2. abdominal cavity, surgeon should suspect some errors in pneumoperitoneum technique. These errors may be leak or may be preperitoneal space creation or extravasations of gas. The detail principles and techniques of safe access are discussed in Chapter 6: Abdominal Access Techniques. SUCTION/IRRIGATION SYSTEM It is used for flushing the abdominal cavity and cleaning during endoscopic operative intrusions (Fig. 2). It has been designed for use with the 26173 AR suction/ instillation tube. Its electrically driven pressure/suction pump is protected against entry of bodily secretions. The suction irrigation machine is used frequently at the time of laparoscopy to make the field of vision clear. Most of the surgeons use normal saline or Ringer’s lactate for irrigation purposes. Sometime heparinized saline is used to dissolve blood clot to facilitate proper suction in case of excessive intra-abdominal bleeding. Irrigation and Suction Tubes A suction-irrigation probe can be a versatile instrument. Laparoscopic suction and irrigation tube is one of the very important instruments which surgeon should practice frequently (Fig. 3). Vision is one of the limitations of laparoscopic surgery. The blood is the darkest color inside abdominal cavity and excess of blood inside absorbs most of the light. Whenever there is bleeding, one should first try to suck it out. Controlled suction and irrigation enhance the observation and improve operative technique. Suction and Fig. 2: Laparoscopic suction irrigation machine. Total Gas Used This is the fourth indicator of insufflator. Normal size human abdominal cavity needs 1.5 L CO2 to achieve intra-abdominal actual pressure of 12 mm Hg. In some big size abdominal cavity and in multipara patients, sometime we need 3 L of CO2 (rarely 5–6 L) to get desired pressure of 12 mm Hg. Whenever there is less or more amount of gas is used to inflate a normal Fig. 3: Laparoscopic irrigation and suction tubes. 35
SECTION 1: Essentials of Laparoscopy irrigation tube also can be used for blunt dissection. At the time of using suction and irrigation, the tip of the suction irrigation cannula should be dipped inside blood, otherwise the gas will be sucked and surgeon will lose his vision due to loss of pneumoperitoneum. 10-mm suction tube should be used if there is >1,500 mL of hemoperitoneum or if there is blood clots inside the abdominal cavity. Sometime small spilled stones can also be sucked with the help of laparoscopic irrigation suction tube at the time of laparoscopic cholecystectomy. It is very useful instrument for doing peritoneal toilet in case of appendicular or duodenal perforation. ENERGY SOURCE SYSTEM Electrosurgery is the use of radiofrequency alternating current to cut and coagulate tissues. It has proven a major advance in surgery by minimizing blood lose, reducing operative time, and providing a clear and clean surgical field without the need to tie off all blood vessels. In laparoscopy, cutting and the establishment of hemostasis forms the core of laparoscopic surgery. For a laparoscopic hernia repair, both monopolar and bipolar modes are required. Spatula is either “W” shaped or blunt. Hooks are also of various shapes, e.g., “L” shaped, “J” shaped or “U” shaped (Fig. 5). Hooks are simple instrument whose distal tip can vary slightly. They must be insulated along the entire length because they are used with the monopolar current. The hook with ceramic cone protecting the distal end is available which protects efficiently against current diffusion (Fig. 6). Some ball-shaped, barrel-shaped or straight coagulation electrodes are also available to achieve proper hemostasis. These blunt electrodes are particularly useful when there is generalized oozing of blood and surgeon cannot see specific bleeder point, e.g., bleeding from the gallbladder bed at the time of laparoscopic cholecystectomy. These blunt electrosurgical instruments are also used for fulguration at the time of ablation of endometriosis. Bipolar Forceps Spatula and hook are the main electrodes used for monopolar cutting and coagulation (Fig. 4). Bipolar forceps are one of the very important electrosurgical instruments in minimal access surgery (Fig. 7). It is safer than monopolar instruments because electron travels only through the tissue held between the jaw and patient’s body is not a part of circuit. Both the jaws of bipolar are insulated and the patient return plate is not necessary to be attached (Fig. 8). The detailed principle of electrosurgery is discussed later in laparoscopic dissection techniques. Fig. 4: Spatula. Fig. 5: Various types of hooks. Fig. 6: Ceramic coating of hook. Fig. 7: Bipolar forceps. Coagulating and Dissecting Electrodes
Fig. 9: Veress needle. Fig. 8: Jaw of bipolar forceps. LAPAROSCOPIC WORKING INSTRUMENT Disposable or Reusable Instrument Several factors should be considered at the time of choosing laparoscopic instrument, including cost, availability, and reliability. Reusable instruments are expensive initially but in long run they are cost-effective. The cost of disposable instruments is less compared to reusable but patient cost is increased. In developing countries, disposable instruments are very rarely used because labor cost is low compare to the cost of disposable instrument. In Europe and the United States of America, surgeons often choose to use disposable instrument in order to save high labor cost. The main advantage of disposable instrument is high performance due to its sharpness and reduced chance of disease transmission due to certified high-end factory sterilization. However, once discarded, environment concerns are raised about disposal and biodegradability of disposable instruments. Ideally, disposable instrument should not be used repeatedly because handling, sorting, storing, and sterilization make these instruments questionable. The disposable instruments are not sterilized properly by dipping in glutaraldehyde because they are not dismountable. Insulation of disposable instrument also can be torn easily which can lead to electrosurgical injuries. Insufflation Cannulas Veress Needle Veress needle was invented by a chest physician for aspiration of pleural effusion keeping in mind that its spring mechanism and blunt tip will prevent the injury of lung tissue (Fig. 9). Veress needle consists of an outer cannula with a beveled needle point for cutting through tissues. Inside the cannula is an inner stylet, which is loaded with a spring that “springs forward” in response to the sudden decrease in pressure encountered upon crossing the abdominal wall and entering the peritoneal cavity. The lateral hole on this stylet enables CO2 gas to be delivered intra-abdominally. Veress needle is used for creating initial pneumoperitoneum so that the trocar can enter safely and the distance of abdominal wall from the abdominal viscera should increase. Veress needle technique is the most widely practiced way of access. Before using Veress needle every time, it should be checked for its potency and spring action. Veress needle is available in three length 80 mm, 100 mm, and 120 mm. In obese patient 120 mm and in very thin patient with scaphoid abdomen 80 mm Veress needle should be used. Veress needle should be held like a dart at the time of insertion. Hasson Cannula In an effort to decrease the incidence of injuries associated with the blind access of the peritoneal cavity with the Veress needle and the initial trocar, Hassan proposed a blunt (open) minilaparotomy access. He develops a reusable device of similar design to a standard cannula but attached an oliveshaped cone (sleeve) (Fig. 10). This cone would slide up and down the shaft of the cannula and would form an airtight seal at the fascial opening. In addition, the sharp trocar was replaced by a blunt obturator. This cannula is held in place by the use of stay sutures passed through the fascial edges and attached to the body of the cannula (Fig. 11). The reason the olive sleeve is designed to slide up and down the shaft of the cannula is to allow for variations in abdominal wall thickness. The tension provided by the fascial sutures when attached to the device serves to create a seal to prevent gas leakage. To adjust the length of the cannula within the abdominal wall, the fascial sutures require detachment from the device, adjustment of the olive sleeve and reattachment of the sutures. Several disposable open-access devices have been released. They are similar to the reusable system originally described by Hasson except that the stay sutures are attached directly to the olive, allowing manipulation of the cannula depth without detaching the stay sutures. The basic method of peritoneal access, however, has remained the same. 37
SECTION 1: Essentials of Laparoscopy Fig. 10: Hasson trocar and cannula. PORT ACCESS INSTRUMENT Trocar and Cannula The word “trocar” is usually used to refer to the entire assembly but actual trocar is a stylet which is introduced through the cannula. The trocars are available with different types of tips. The cutting tips of these trocars are either in the shape of a three-edged pyramid or a flat two-edged blade. Conical-tipped trocars are supposed to be less traumatic to the tissue. The tip can be penetrated through the parietal wall without cutting and decreased risk of herniation or hemorrhage is reported. Cannulas are in general made from plastic or metal. Plastic devices whether they are transparent or opaque, need to be designed in such a way as to minimize the reflection of light from the telescope. Reusable and disposable trocars are constructed by a combination of metal and plastic. The tip of disposable trocar has a two-edged blade. These are very effective at penetrating the abdominal wall by cutting the tissue as they pass through. Most of the disposable plastic trocars have spring-loaded mechanism that withdraws the sharp tip immediately after it passes through the abdominal wall to reduce the incidence of injury of viscera. Trocar and cannula are of different sizes and diameter depending upon the instrument for which it is used. The diameter of cannula ranges from 3 to 30 mm; the most common size is 5 mm and 10 mm. The metal trocar has different types of tips, i.e., pyramidal tip, eccentric tip, conical tip or blunt tip depending on the surgeon’s experience (Fig. 12). All the cannulas have valve mechanism at the top (Figs. 13A and B). Valves of cannula provide internal air seals, which allow instruments to move in and out within cannula without the loss of pneumoperitoneum. These valves can be oblique, transverse, or in piston configuration. These valves can be manually or automatically retractable during instrument passage. Trumpet type valves are also present which provide excellent seals, but they are not as practical as some of the other systems. They require both hands during instrument insertion, which may explain why they are less often used in advanced laparoscopic cases. Fig. 11: Hasson cannula in proper position. Fig. 12: Tip of the trocar. The flexible valves limit the leakage of CO2 during work whatever the diameter of the instrument used. It should be remembered that sharp trocars although looking dangerous are actually better than blunt one because they need less force to introduce inside the abdominal cavity and chances of inadvertent forceful entry of full length of trocar are less. There is always a difference in the marked exterior diameter of the cannula and the interior usable diameter. The end of the cannula is either straight or oblique. An oblique tip is felt to facilitate the easy passage of the trocar through the abdominal wall. Trocar and cannula should be held in proper way in hand so that head of the trocar should rest on the thenar eminence, the middle finger should rest over the gas inlet and index finger is pointed toward the sharp end of the trocar. Visiport The Visiport is a kind of optical trocars which is a disposable and expendable visual entry tool which includes a cannula and hollow trocar with cutting blade at tip (Fig. 14). It is applied after insufflation of CO2 in the abdomen. This technique of inserting Visiport is palmed via surgeon’s hand and maintained perpendicular to distend patient’s CO2 to abdomen. When accurate anatomical status of trocar tip
A B Figs. 13A and B: (A) Different valve mechanism of cannula; (B) Different valve mechanism of cannula (internal view). Fig. 14: Visiport. is checked by visualization of layers of abdominal wall on monitor, downward axial pressure is used and activated to trigger cutting blade. Downward pressure causes trocar to advance optical bladed tip and its situation is checked again and again seeing on the monitor. These sequences are repeated till the peritoneal cavity is arrived. This is not fired till the accurate anatomical status of trocar tip is known. However, none of the laparoscopic entry methods have distinct superiority over other. On the other words, Visiport technique is also associated with abundant complication. Visiport optical trocar technique is faster for initial trocar placement than Hasson technique. However, it is associated with complications compared to open Hasson technique. Therefore, there is benefit with respect to speed for initial trocar placement and harm based on complications of sharp cutting blade in Visiport trocar system. Bladeless Optical Trocar There are many single-use bladeless optical trocar systems available which provide a versatile, operationally flexible, and unique mode of entry into the abdominal cavity for any laparoscopic procedure (Fig. 15). The distinctively engineered visual tip greatly reduces wound defect size as well as insertion force into the abdominal cavity. Injuries due to blind entry and a sharp blade are virtually eliminated with the use of bladeless optical tip trocar system. The optical tip provides direct visualization of the various tissue layers when accompanied by a laparoscope during insertion. Because the bladeless tip separates and dissects without cutting, trauma to the abdominal wall and vessels are minimized. Fig. 15: Bladeless optical trocar. Fig. 16: Step radially expanding trocar. Step Trocar Step radially expanding technology allows the VersaStep bladeless trocars to yield smaller fascial defects for an equivalent cannula size compared to conventional bladed trocars. The VersaStep bladeless trocars use Step radial dilation technology. The VersaStep system can be found in a 70 mm, 110 mm or 150 mm working length and can be 5 mm, 11 mm, 12 mm or 15 mm in diameter. The trocars are designed to keep fascial issues from being a threat. It can keep gas completely airtight within the abdominal cavity and can help allow instruments from 4.5 mm, 12 mm or 15 mm to be exchanged as needed. In this technology initially less diameter trocar is introduced which is stretchable. Over this stretchable cannula again desired diameter of trocar is pushed to radially dilate the abdominal port wound. This results in less chance of hernia. This trocar system is strictly disposable and cannot be used second time as outer sheath breaks after single use (Fig. 16). 39
SECTION 1: Essentials of Laparoscopy LAPAROSCOPIC HAND INSTRUMENTS Laparoscopic hand instruments vary in diameter from 1.8 to 12 mm but majority of instruments are designed to pass through 5–10 mm of cannula. The hand instruments used in laparoscopic surgery are of different length (varies companyto-company and length of laparoscopic instrument varies from 18 to 45 cm) but they are ergonomically convenient to work if they have same length of approximately 36 cm in adult and 28 cm in pediatric practice. Shorter instruments 18–25 cm are adapted for cervical and pediatric surgery. Certain procedures for adult can also be performed with shorter instruments where the space is constricted. 45-cm instruments are used in obese or very tall patients. For better ergonomics, half of the instruments should be inside the abdomen and half outside. If half of the instrument is in and half out, it behaves like class 1 lever and it stabilizes the port nicely so the surgery will be convenient. A Most of the laparoscopic procedures require a mixture of sharp and blunt dissection techniques, often using the same instrument in a number of different ways. Many laparoscopic instruments are available in both reusable and disposable version (Figs. 17A to C). Most reusable instruments are partially dismountable so that it can be cleaned and washed properly. Some manufacturers have produced modular system where part of the instrument can be changed to suit the surgeon’s favorite attachment like handle or working tip. Most laparoscopic instruments such as graspers and scissors have basic opening and closing function (Figs. 18A and B). Many instrument manufacturers during past few years are able to rotate at 360° angle which increases the degree of freedom of these instruments (Fig. 19). Certain types of instrument offer angulations at their tip in addition to usual 4° of freedom. These instruments are B C Figs. 17A to C: (A) Disposable trocar and cannula; (B and C) Disposable trocar and cannula (another view). A B Figs. 18A and B: (A) Disposable grasper; (B) Reusable graspers.
Fig. 19: Articulation of hand instrument. Fig. 20: Different types of handle of hand instrument. Fig. 21: Cuschieri ball handle. Fig. 22: Cuschieri pencil handle. used to avoid obstacles and for the lateral grasping when the instrument is placed outside of the visual field. This feature is available for both reusable as well as disposable instrument. The complex mechanism of such instrument makes their sterilization very difficult. A variety of instruments, especially retractors have been developed with multiple articulations along the shaft. When these are fixed with the tightened cable, the instrument assumes a rigid shape which could not have been introduced through the cannula. Some multifunctional laparoscopic handles have attachment for suction and irrigation and sometime hand switch for cutting and coagulation switch of electrosurgery. Cuschieri ball handle, invented by Professor Sir Alfred Cuschieri, lies comfortably in surgeon’s palm (Fig. 21). This design reduces the fatigue of surgeon and eases rotation of the instrument by allowing rotation within the palm rather than using wrist rotation. Squeezing the front of the handle between the thumb and the first finger increases the jaw closing force; squeezing the rear of the handle between the thenar eminence of the thumb and last finger opens the jaws. Cuschieri pencil handle also has great ergonomic value especially when used with needle holder (Fig. 22). This multifunctional laparoscopic handle allows the angle between the handle and the instrument to be altered to suit the surgeon’s wrist angle. The conveniently placed lever of this pencil handle when pressed can change the angle. Just like ball handle, pressure at the front increases the jaw closing force while pressure at the rear opens the jaw (Fig. 23). Most of the hand instruments haves three detachable parts: 1. Handle 2. Insulated outer tube 3. Insert which makes the tip of the instrument. Different Handles of Hand Instrument Certain instrument handles are designed to allow locking of the jaw (Fig. 20). This can be very useful when the tissue needs to be grasped firmly for long period of time preventing the surgeon’s hand from getting fatigue. The locking mechanism is usually incorporated into the handle so that surgeon can easily lock or release the jaws. These systems usually have a ratchet so that the jaws can be closed in different position and to different pressure. Most of the laparoscopic instrument handles have attachments for unipolar electrosurgical lead and many have rotator mechanism to rotate the tip of the instrument. OUTER SHEATH OF HAND INSTRUMENT The insulation covering of outer sheath of hand instrument should be of good quality in hand instrument to prevent accidental electric burn to bowel or other viscera (Fig. 24). Insulation covering may be of silicon or plastic. At the time of cleaning the hand instrument, utmost care should 41
SECTION 1: Essentials of Laparoscopy Fig. 23: Multifunctional laparoscopic handle. Fig. 24: Outer sheath of hand instrument. Fig. 25: Insert of hand instrument. Fig. 26: Different jaw of graspers. Fig. 27: Double-action jaw graspers. Fig. 28: Serrated jaw graspers. be taken so that insulation should not be scratched with any sharp contact. A pin hole breach in insulation is not easily seen by naked eye but may be dangerous at the time of electrosurgery. Single-action Jaw Graspers Insert of Hand Instrument Double-action Jaw Graspers Insert of hand instrument varies only at tip (Fig. 25). It may be graspers scissors, or forceps. This grasper may have single-action jaw or double-action jaw. Single-action jaw opens less than double-action jaw but close with greater force. Thus, most of the needle holders are single-action jaw. The necessary wider opening in double-action jaw is present in grasper and dissecting forceps. Single-action graspers and dissectors are used where more force is required (Fig. 26). These are shown in Figures 27 and 28. These graspers are good when you do not have control over depth and surgeon wants to work in single plane in controlled manner particularly during adhesiolysis. INSTRUMENTS FOR SHARP DISSECTION ■ Scissors ■ Electrosurgery hook ■ High-frequency (HF) electrosurgery spatula (Berci) ■ HF electrosurgery knife ■ Knife.
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