Equipment detail 1, Equipment detail 2, Equipment detail 3, Equipment detail 4, Equipment detail 5
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READ ABOUT LAPAROSCOPIC EQUIPMENT AND INSTRUMENTS
Many surgeons says "Laparoscopy is the by product of medical engineering". Laparoscopy was initially criticized due to the cost of instruments and possible complications due to these sharp long instruments and difficult hand eye co-ordination. Many senior surgeon started saying "Laparoscopy is conspiracy against common man". Minimal access surgery has developed rapidly only after grand success of laparoscopic cholecystectomy. Recently computerized designing of laparoscopic instrument is introduced and microprocessor controlled safety features are added. Now it is impossible to stop the speed of growth of minimal access surgery and every day new procedures are added on its list. Laparoscopy is a technologically dependent surgery and before starting surgery every surgeon should have reasonably good knowledge of these instruments.
Laparoscopic Trolley
The mobile video cart is equipped with locking brakes and has 4 anti-static rollers. The trolley has a drawer and three shelves, the upper shelves have a tilt adjustment and used for supporting the video monitor unit. Included on the trolley is an electrical supply terminal strip, mounted on the rear of the 2nd shelf (from the top). Recently ceiling mounted trolleys are launched by many companies which is ergonomically better and consume less space in operation theatre.
Light cable and light source
Light is essential for performing most of the modus operandi of life. Thanks to Edison who discovered electric bulb. The Minimal access surgery depends on the artificial light available in closed body cavity, and before the discovery of light source and light cable; mirrors were used to reflect the light onto the subject where the direct light access was not possible.
In Bruck, a Dentist from Breslau, made a platinum wire loop which he heated with electric current, and used that as a light source for purpose of surgery. Endoscopy was performed, by using tungsten light bulbs inside the body cavity before . These bulbs were emitting low frequency red color of light. The bulb was so hot that there was always a risk of injury to bowel.
Fibre Optic Cables:
In a major breakthrough in technology occurred in the development of fibre optic cables. The principle of fibre optic cable was based on the total internal reflection of light. Light can be conducted along a curved glass rod due to multiple total internal reflections at the walls of the rod. Light would enter at one end of the fibre and emerge at the other end after numerous internal reflections with virtually all of its strength.
Nowadays there are two types of light cable available in market.
Optic cables
These cables are made up of a bundle of optical fibres glass thread swaged at both ends. The fibre size used is usually between 10 to 25 mm in diameter. They have a very high quality of optical transmission, but are fragile. In fact, progressively as they are used, some optical fibres break. The loss of optical fibres may be seen when one end of the cable is viewed in daylight. The broken fibres are seen as black spots.
Gel cables
These cables are made up of a sheath that is filled with a clear optical gel (Liquid crystal). Theoretically they are capable of transmitting 30% more light than optic fibres. Due to more light and better color temperature transmission this cable is recommended in those circumstances where documentation (movie, photography or TV) is performed. They pose three problems:
The quartz swaging at the ends is extremely fragile, especially when the cable is hot. The slightest shock, on a bench for example, can cause the quartz end to crack and thus cause a loss in the transmission of the light;
· These cables transmit more heat than optical fibre cables.
· These cables are made more rigid by a metal sheath, which makes them more difficult to maintain and to store.
In conclusion, even though the choice is a difficult one, we use optical fibre cables, which are as fragile as the gel cables but their flexibility makes them much easier to maintain.
Attachment of Light Source:
DIC Attachment
Conventional attachment has at right angle connection for light source and camera. Recently some new attachment for light cable is available known as DIC Interface. The benefit of this is that it maintains upright orientation regardless of angle of viewing, using auto Rotation system. It also provides single handed control of the entire endoscope camera system.
Maintenance of light cable:
The light source:
One of the advantages of the laparoscopy is that of obtaining a virtually micro-surgical view compared to that obtained by laparotomy. Quality of the image obtained very much depends on the quantity of light available at each step of optical and electronic system.
A typical light source is consist of
Lamp:
Lamp or bulb is the most important part of the light source. The Quality of light depends on the lamp used. Several Modern types of light sources are currently available on the market. These light sources mainly differ on the type of bulb used. Four types of lamp are used more recently.
Halogen bulbs
Halogen bulbs provide a highly efficient, almost crisp white light source with excellent color rendering. Electrodes in halogen lamps are made of tungsten; this is the only metal with a sufficiently high melting temperature and sufficient vapor pressure at elevated temperatures. They use a halogen gas that allows bulbs to burn more intensely without sacrificing life. Halogen bulbs are low voltage and have an average life of 2,000 hours. Color temperature of Halogen lamp is (- K). These lamps are cheap and can be used for laparoscopic surgery if low budget setup is required.
Xenon lamps
Xenon lamps consist of a spherical or ellipsoidal envelope made of quartz glass, which can withstand high thermal loads and high internal pressure. For ultimate image quality, only the highest-grade clear fused silica quartz is used. It is typically doped, although not visible to the human eye, to absorb harmful UV radiation generated during operation. The colour temperature of Xenon lamp is - K. The operating pressures are tens of atmospheres at times, with surface temperatures exceeding 600 degrees C.
The smaller, pointed electrode is called the cathode, which supplies the current to the lamp and facilitates the emission of electrons. To supply a sufficient amount of electrons, the cathode material is doped with thorium. The optimum operating temperature of the cathode tip is approximately degrees C. To obtain this precise operating temperature, the cathode tip is pointed and in many cases has a groove on the pointed tip to act as a heat choke. This heat choke causes the tip to run at a higher temperature. This configuration of the cathode tip allows for a very high concentration of light from the cathode tip and a very stable arc.
The anode, the larger electrode, receives electrons emitted by the cathode. Once the electrons penetrate the anode face, the resulting energy is converted to heat, most of which radiates away. The large, cylindrical shape of the anode helps to keep the temperature low by radiating the heat from the anode surface.
Metal halide vapor arc lamp.
In metal halide lamp the mix of compounds (comprising mostly salts of rare earths and halides as well as the Mercury which provides the conduction path) is carefully chosen to produce an output which approximates to 'white' light as perceived by the human eye. There are two type of Metal halide lamp generally used:
Iron Iodide Lamp
Iron Iodide is a broad emitter and enhances the spectral output of the lamp in the 380nm region.
Gallium Iodide Lamp
Gallium Iodide has the effect of introducing spectral lines at 403 nm and 417 nm of the electromagnetic spectrum.
The intensity of the light delivered by any lamp is also depends on the power supply of the source. However, increasing the power poses a real problem as concerns the heat created. At present, the improvements made to the cameras means that it is possible to return to reasonable power levels, of the order of 250 Watts. 400 W units are, however, preferable in order to guarantee sufficient illumination of the abdomen even when bleeding causes strong light absorption.
The most frequently used two main types of lamps are halogen and xenon. This difference may be remarked in the colors obtained, the xenon having a slightly bluish tint. The light emitted by xenon lamp is more natural compared to halogen lamp. However, most of the cameras at present analyze and compensate these variations by means of automatic equalization of whites ( K to K), which allows the same image to be obtained with both light sources.
A proper white balancing before start of the operation is a very good practice for obtaining a natural color. The white light is composed of the equal proportion of Red, Blue and Green Color and at the time of white balancing the camera sets its digital coding for these primary colors to equal proportion assuming that the target is white. And if at the time of white balancing the telescope is not seeing a perfectly white object then the setup of the camera will be very bad and the color perception will be very poor.
The newer light source of Xenon, now a day used is defined as a cool light but practically it is not completely heat free and it should be cared for ignition hazard.
Heat Filter
For 100 % of energy consumed, a normal light source (a light bulb) uses approximately 2 % in light and 98 % in heat. This heat is mainly due to the infrared spectrum of light and due to obstruction in the pathway of light. If Infrared will travel through the light cable than the cable will become intolerable hot. A heat filter is introduced to filter this infrared to travel in fibre optic cable. A cool light source lowers this ratio by creating more light, but does not reduce the heat produced to zero. This implies a significant dissipation of heat, which increases as the power rating increases. The sources are protected against transmitting too much heat at present. The heat is essentially dissipated in transport, along the cable, in the connection with the endoscope and along the endoscope.
Some accidents have been reported due to burning caused by the heat of the optics system. It is therefore important to test the equipment, particularly if assemblies of different brands are used.
A condensing lens
The purpose of condensing lens is to converge the light emitted by lamp to the area of light cable input. In most of the light source it is used for increasing the light intensity per square cm of area.
The Interface of a standard light source
It is essential to know about all the switch and function of the light source. All essential details of the equipment and all the action required on the part can be found on the operating manual of the product.
Manual or automatic intensity control circuit
Manual adjustment allows the light source to be adjusted to a power level defined by the surgeon. When video cameras are used, close-up viewing is hampered when there is too much light, whereas more distant views may be too dark. To counter this problem, the luminosity of most of the current light sources is adjustable.
Automatic adjustment: The advance light source system is based on the automatic intensity adjustment technology. The video camera transforms the signal into an electronic signal. This electronic signal is coded in order to be transported. The coding dissociates the luminance and chrominance of the image. The luminance is the quantity of light of the signal (black and white) that dictates the quality of the final image. When there is too much light for the image,(when the endoscope is near to the tissue) the luminance signal of the oscilloscope increases. On the other hand, when the luminosity is low, (distant view or red surroundings), the luminance is low and the electronic signal much weaker. A good quality luminance signal is calibrated to 1 milli volt. Overexposed images make the electronic signal pass above one millivolt, whereas underexposed images make the signal drop below one millivolt. Light sources equipped with adjustment analyze the luminance. If the signal is significantly higher than 1 millivolt, they lower the power and bring the signal back within the standards. Inversely, if the signal is too weak, they increase their intensity.
These systems are extremely valuable, permitting work to be performed at different distances from the target in good viewing conditions. However, the cameras currently available are often equipped with a regulation system, which are capable of automatic gain control in poor light condition and the purchase of a light source with adjustment associated with a camera equipped with an adjustment system is a double purchase that is unnecessary.
Troubleshooting of Laparoscopic Light Source
Inadequate lighting:
Probable causeRemedyLoose connection at source or scopeAdjust connectorLight is on "manual-minimum'Go to "automatic"Bulb is burned outReplace bulbFiber optics are damagedReplace light cableAutomatic iris adjusting to brightDim room lightsreflection from instrumentRe-position instruments, or switch to "manual"A laparoscopic surgeon should be technically well acknowledged of the principle of the instrument they are using, and should not always depend upon their technical team should an emergency arrive. The purchase of a costly instrument is not only answer for achieving a good task, perceptive to handle them is equally important.
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READ ABOUT LAPAROSCOPIC EQUIPMENT AND INSTRUMENTS
Few among hundred of Surgeons & Gynaecologists trained at our Hospital
Storz is the main supplier to the World Laparoscopy Hospital
The mobile video cart is equipped with locking brakes and has 4 anti-static rollers. The trolley has a drawer and three shelves, the upper shelves have a tilt adjustment and used for supporting the video monitor unit. Included on the trolley is an electrical supply terminal strip, mounted on the rear of the 2nd shelf (from the top).
The video cold tight fountain has a high light intensity HT I lamp making the instrument particularly suited for endoscopic examinations.
When a video system has been connected, the cold light fountain can be adjusted automatically when using the &#;BY VIDEO&#; operating mode or can be adjusted manually.
Storz light cables are flexible fibreoptic cables, which connect the light source to the telescope.
Normally used telescope is the Hopkins Forward Oblique Telescope 30°, diameter 10mm length 33cm, and is autoclavable. At the distal end is a front lens complex (inverting real-image lens system, IRILS) which creates an inverted and real image of the subject. A number of IRILS transport the image to the eyepiece containing a magnifying lens. In the Hopkins rod-lens system light is transmitted through glass columns and refracted through intervening air lenses. The 30 forward oblique permits far greater latitude for viewing underlying areas under difficult anatomical conditions.
The Sony Trinitron Colour Video monitor can display PAL, SECAAM, NTSC 3.58 and NT SC 4.43 signals. The appropriate colour system is selected automatically. The aperture, brightness, chroma, phase contrast and volume buttons are controlled by light touch buttons. These settings are retained in memory even when the monitor is switched off. The monitor operates on 220-240 Volts AC. The automatic beam current feedback circuit compensates for beam distortion and always reproduces the same white display on the screen, the super fine pitch Trinitron picture tube giving a high resolution picture of more than 600 lines.
The Endovision is an easy to use camera system suitable for use in all types of endoscopic examinations. The camera is equipped with a zoom lens allowing continuous adjustment of image magnification over a wide range. Lens aperture adjustment and white equalization are fully automatic. Video output is available in the form of both component (RGB) and S-VHS signals. The camera dimensions are 28mm diameter, 68mm length, and 0.1 kg weight.
The Electronic CO2 Laproflator is a general purpose insufflation unit for use in laparoscopic examinations and operations. The required values for pressure and flow can be set exactly using jog keys and digital displays. Insufflation pressures can be continuously varied from 0 to 30 mm Hg; total gas flow volumes can be set to any value in the range 0-9.9 liters/mm. Patient safety is ensured by optical and acoustic alarms as well as several mutually independent safety circuits
The Storz Pelvi-Cleancr is used for flushing the pelvic basin during endoscopic operative intrusions. It has been designed for use with the AR suction /instillation tube. Its electrically driven pressure/suction pump is protected against entry of bodily secretions.
Most endoscopic procedures require a mixture of sharp and blunt dissection techniques, often using the same instrument in a number of different ways.
For more information, please visit Laparoscopic Instrument.
Instrument used
The use of scissors endoscopically requires little modification of open techniques. The basic instrument is a miniaturized, long handled version of conventional scissors and can be single or double action. There are some special types of scissors used in endoscopic surgery:
These allow the use of electrocautery through the scissors. However when using non-disposable instruments, electro coagulation using the open blades leads to blunting of the edges. Electro coagulation using the scissors is thus limited in this unit, and when carried out is applied only with the blades closed. Scissor dissection is usually carried out with a grasper in the other hand to tension the tissues. If this instrument is insulated then any vessels encountered can be easily coagulated by the grasper. A further disadvantage associated with electro coagulation with the scissors results from the long non-insulated segment required to accommodate the blades and hinge mechanism. For safe practice this requires to be kept in view and this limits the magnification available to the surgeon.
The sharp edge of both blades is in the shape of a flattened C. The blades can be partially closed trapping tissue in the hollow of the blades without dividing it and allowing it to be slightly retracted. This allows the surgeon to double check before he closes the blades completely.
These have a curve to the blades which may improve visibility of tissues within the jaws of the instrument.
These very fine scissors, are either straight or angled, and are used to partially transect the cystic duct.
These scissors are mounted on a curved handle which is either fixed or retractable. The types with a fixed curvature proximal to the scissor blades require introduction through flexible valve-less ports.
We request that you use only the single action, insulated scissors as suture scissors to avoid blunting the dissecting scissors.
The knife is not used frequently in endoscopic surgery due to the problems associated with the safety of a blade, which cannot be closed or deactivated. However it does have some important uses;
In our practice a disposable blade (Beaver) is mounted on a metal rod, which has a socket at the distal end into which it can be screwed.
The most common use of the knife is for opening the hepatic duct or common bile duct during exploration for stones. A small, clean cut, linear stab wound is created in the anterior wall. Great care is required during incision and removal of the knife. However a sharp curved scissors is better and safer than the endoknife for the choledochotomy.
Instrument used
Methods
HF electrosurgery is the application of HF currents (in the frequency range of 300 kHz up to several MHz) to coagulate, fulgurate, spray coagulates or ablates tissue. Knowledge of how this and other physical modes interact with biological materials is becoming increasingly important to the surgeon for safe and consistent surgery.
Monopolar diathermy is used in endoscopic surgery for coagulation and for dissection (cutting). During monopolar diathermy current is conducted from the instrument through the tissues to a skin pad (neutral electrode) connected back to the generator. Heating occurs at sites of small cross section and low electrical conductivity. The instruments contact with the tissue has a small cross sectional area and the tissue is of relatively low conductivity (higher resistance or impedance) compared to the instrument material. A high current density occurs in the tissue in immediate contact with the instrument and heat is generated.
The effect of HF current on the tissues depends on:
A bipolar system is inherently safer as the interaction is restricted to the immediate vicinity of contact and the current does not pass through the patient but instead returns to the generator via the receiving pole after passage through the grasped tissue. Bipolar probes are now available for coagulation as well as for cutting. The cutting system is not strictly bipolar and is hence referred to as quasi-bipolar electrocutting.
These are generally L or open C shaped, blunt ended rods mounted on an insulated handle. The active, non-insulated part is limited in size. The hook is a delicate instrument and should be protected during insertion by manual opening of the cannula valve or use of a reducing tube. As electrosurgery generates smoke (which is harmful), many handles of electrosurgical hooks have a suction attachment at the other end of the handle.
Electrosurgical instruments like the hook are useful as blunt dissectors prior to activation. They are used to isolate the tissue to be divided by the current. The tip is passed into or under a layer of the tissue being dissected, which is then hooked and tented up (to increase its impedance and thus limit the spread of current when applied). Small portions of tissue are tackled so that an assessment of the tissue caught on the hook can be made before coagulation or cutting current is applied to the instrument. The hook can be used to clear unwanted tissue beside linear structures by passing the hook into the tissues parallel to the structure, and then rotating it to hook up strands of unwanted tissue. The tissue to be divided is held away from underlying tissue to prevent inadvertent damage. Short bursts of coagulating current can be followed by the use of cutting current, if the tissue has not already separated.
The use of the hook can be summarized as &#;HOOK, LOOK, COOK&#;.
The hook or the spatula may also be used to mark out and coagulate a line for division. The heel of the hook is used with the HF current set to soft coagulation. Short bursts are applied and the hook moved along to create a &#;dotted&#; line of coagulated tissue. Where deeper penetration is desired the point of the hook maybe appropriate, a second pass being performed to hook up the intervening bridges. This type of contact is best reserved for situation where no significant damage can be caused by current penetration.
For endoscopic surgery, this is usually a straight pointed needle which is extruded from inside a straight insulated handle. In the quasi bipolar systems, the rounded end of the handle is capped by metal and is used for electrocoagulation, whereas the needle electrode when extruded from the centre of the end of the handle serves as the cutting knife.
This requires extreme caution due to the relatively large portion of the instrument which is live. The use of electrical current will lead to coagulum formation, and arcing and ionization will quickly blunt the blades. It is advisable to restrict the use of diathermy to disposable single use scissors.
Basic Instruments & Technology.
I. Basic Instruments
Pneumoflator
The first requirement for laparoscopy is the provision of a safe pneumoperitoneum. The mechanically monitored pneumoflator is adequate for diagnostic laparoscopy and relatively simple operations. It allows continuous flow of carbon dioxide (CO2) with automatic refilling of the abdomen which can be augmented by rapid refill at a rate of 3 l/min under direct visual control. The intra-abdominal pressure and the volume of gas must be kept within safe limits.
An electronic CO2 pneumoflator should be used when complex operations are being performed. This is fully automatic and simultaneously measures the intra-abdominal and insufflation pressures which can be preset to cut out at a selected level. The gas deficit is also electronically determined and can be replaced at a rate of 6 1/min.
When performing operative laparoscopy it is safer to use carbon dioxide (CO2) than nitrous oxide (N2O). Carbon dioxide is 20-fold more soluble in blood and body fluids than air or oxygen. However absorption at a rate of over 100ml/min may lead to hypercarbia and cardiac arrhythmia. This can be prevented by hyperventilation and controlled positive pressure respiration. In all cases where CO2 is used, the patients pulse rate and blood pressure and blood gases should be continuously recorded to detect the earliest signs of circulatory or biochemical changes. Carbon dioxide pneumoperitoneum may also cause postoperative pain as a result of formation of hydrocarbonic acid which is irritant to the peritoneum. Nitrous oxide is safer as regards circulatory changes but any advantage in this respect is offset by the fact that it can support combustion.
The gas is introduced into the abdomen with a spring-loaded, needle originally designed by Veress of Budapest in for the production of pneumothorax in the treatment of pulmonary tuberculosis. The Veress needle is available in three different lengths. Normally the 7cm needle should be used but longer ones up to 15cm in length are available for obese patients or for introducing the pneumoperitoneum through the posterior fornix.
The sharp needle point is automatically withdrawn into its sheath by the spring which allows the needle to be used as a probe for lifting organs and palpating their consistency.
Trocars and Cannulae
The choice of trocar is debatable. The pyramidal trocar is easier to insert but is more likely to perforate a blood vessel in the abdominal wall. The conical trocar, although safer in that respect, requires a stronger thrust to insert it with consequent risk of accidentally perforating intra-abdominal organs.
As with all instruments, the trocars tend to become blunt with use. Disposable trocars have become popular in recent years because they are always sharp and so can be introduced with less force. However, they are expensive.
Laparoscopes
The development of the rod lens in by Professor Hopkins of Reading has improved the performance of laparoscopes giving a brighter image with better definition and a wider viewing angle. A 5mm telescope may be satisfactory for standard diagnostic laparoscopy. The 10-11 mm instrument is preferable for video laparoscopy and for operative procedures. The majority of laparoscopists prefer to use an O degree instrument. The 30degree laparoscope was designed to enable the surgeon to see aspects of organs which are hidden from direct view.
The lens system of the laparoscope provides magnification of x2 but this can be increased a further twofold by the addition of an endo-loupe to permit laparoscopic microsurgery. Further magnification may be obtained with the use of video monitoring which, with modern high resolution cameras, allows very accurate definition.
Light sources
The standard light source with 150 watt power is satisfactory for diagnostic laparoscopy but, when performing operative laparoscopy or suing closed circuit color television (CCTV), a cold light fountain with 250 watt halogen lamp is necessary. This maintains a constant color temperature and allows automatic variation of the light intensity by the camera. The modern laparoscopist should be trained in video laparoscopy which allows him to work while watching the image on a screen instead of through-the-lens viewing. The light source, video system including video recorder and the pneumoperitoneum apparatus can all be installed in a mobile cart.
Forceps
A variety of forceps are available for diagnostic and operative laparoscopy. The majority of forceps now have scissors grips instead of spring-loaded grips. These allow more accurate manipulation and have a stronger grasp. When using spring-loaded forceps the blades are withdrawn into the shaft of the instrument while they close so it is more difficult to apply them accurately. This may lead to tissue trauma especially during fine tubal surgery. Many modern forceps also have a mechanism to lock them firmly on to tissues.
This allows the operator or assistant to exert constant traction during prolonged dissection of tissues. Two or three grasping forceps should be available. One or two should have atraumatic blades and another should have teeth for stronger traction.
Scissors
Scissors should be fine enough to allow accurate dissection but strong enough not to be blunted by frequent use. This problem has recently been improved by the introduction of self-sharpening scissors but many of the instruments available still have a limited life span and must be replaced frequently. Some gynecologists prefer hook scissors which are designed to pull the tissues into the blades and facilitate cutting but others prefer straight scissors which may be more accurate in use.
It is important that one of the blades is fixed to allow the scissors to put tension on tissues before cutting them.
Fine micro scissors are available for performing delicate surgery when the standard ones would be too large.
Larger scissors introduced through an 11 mm diameter cannula may occasionally be necessary to divide strong pedicles. Similar forceps are used to grasp tough tissues. The 11 mm instruments can be introduced through the abdominal wall by enlarging the original incision with a dilating set which increases the diameter of the incision without further cutting.
Electro-and Thermo coagulation
Safe and effective control of intraperitoneal bleeding is an essential prerequisite for any form of surgery and in laparoscopic surgery can be achieved in several ways. Bleeding may be prevented by careful recognition of the correct tissue plane and by taking care to cut only in an avascular area. Bleeding from minor vessels is also prevented by the raised intra-abdominal pressure produced by the pneumoperitoneum. When bleeding does occur from small vessels it may also be controlled by using lavage fluid at 40 degree centigrade.
The mainstay of haemostasis, however, is elector-or thermo coagulation. The classic instrument for electro coagulation was the forceps designed by Palmer for use with a monopolar current which he originally described for tubal electro coagulation. Unfortunately the high frequency monopolar current was responsible for a number of complications resulting from accidental burns. First, excessive heat production can occur at the operation site and the heat may be directly transmitted to adjacent organs to cause thermal damage. Second, the current must return from the operation site to the return electrode on its way back to the generator. The pathway taken by the current is unpredictable but is usually along the surface of loops of bowel towards the pelvic side walls. The return plate should be large so that the power density of the current is low at the point of contact with the skin.
However, while high frequency monopolar current should not be used for extensive coagulation, modern micro diathermy instruments provide a safe and effective method of cutting fine adhesion, performing neosalpingostomy or coagulating areas of endometriosis.
In Frangenheim of Konstanz introduced bipolar electro coagulation which is safer than monopolar current. In this technique the current passes from one blade of the forceps to the other, coagulating the tissues between the blades. It is still possible for burns to be produced from direct transmission of heat to other tissues. Moreover, if two different electrical generators, one monopolar and the other bipolar, are connected simultaneously to the patient, it is possible for the current generated by the bipolar instrument to be attracted to the return plate of the monopolar generator and to cause inadvertent burns to organs distant from the operation site. It is imperative, therefore, that the monopolar generator is always switched off when bipolar current is being used.
The third type of energy used to secure haemostasis is thermo coagulation in which forceps are heated to 120-140oC for a preset time of 20-40 seconds. The proteins in the tissue between the forceps blades are coagulated. This is probably safer but the tissue response is slower than bipolar electro coagulation.
Laser
Laser has become a popular surgical tool during the past 11 years. It allows precise tissue destruction with highly predictable results. The type, power and delivery system depend on the tissue reaction required, be it vaporization or coagulation. Both rigid and flexible systems are available for laparoscopic surgery. An operating or standard laparoscope may be used.
The commonest laser in use is the CO2 laser which must be delivered via a rigid system of prisms and lenses. The articulated arm of the laser is connected to the laparoscope via the laser coupler which has a joystick for adjusting the direction of the laser beam, a quick-release attachment for the laparoscope and interchangeable lens housing. Alternatively the laser may be connected to a second-puncture prove which may include a smoke evacuating channel. When CO2 laser is being used it is necessary to have a back-stop to prevent damage to tissues beyond the target organ. The other lasers in current use, argon, neodymium:yttrium-aluminum-garnet (Nd:YAG)and potassium-titanic-phosphate (KTP) laser may all be delivered along flexible fiberoptic cables increasing their versatility but requiring directional devices on the introducing channel of the laparoscope. All staff must wear special goggles to prevent eye damage. Some of the risks to operating room staff may be minimized by using video cameras instead of having filters on the lenses. CO2 laser is valuable for incising tissues but is not an effective coagulant. It is always necessary to have available additional means of securing haemostasis such as thermo-or bipolar electro coagulation.
Sutures, Clips and Staples
Haemostasis and tissue apposition may be achieved in laparoscopic surgery by using sutures, clips or fibrin glue. The value of sutures is limited by the difficulty in performing fine surgery when the working distance between the surgeon&#;s hands and the tissue is 35cm or more. The needle must be strong enough to be held with the laparoscopic needle holder but the finest suture material available for endoscopic surgery is 6/0. It is, therefore, impossible to emulate microsurgical suturing in laparoscopic surgery despite the advantages of magnification and the excellent vision obtained with modern endoscopes.
Nevertheless suturing is necessary in some operations although its use in others is debatable. This is because sutures may produce tiny areas of tissue ischemia which may predispose to the formation of adhesion. Ligatures are of value when it is unsafe to use thermal energy. In this case an endoscopic ligature may be applied round the pedicle and the knot tightened by pushing down the tip of the applicator. Sutures may be tied intracorporeally or extracorporeally. The latter knots are simply tightened with a knot pusher.
Hemostatic clips ma be applied to control bleeding or to ligate vessels before dividing them. Staples have now been developed to occlude vessels and simultaneously divide tissues. These are applied with disposable instruments which insert up to three rows of staples in two separate lines. A cutting blade in the applicator then divides the tissues between the rows of staples. This makes division of structures such as the broad ligament rapid and safe. Tissue glue may be used to cover surfaces to prevent adhesion formation or to reperitonize areas where the peritoneum has been removed or destroyed by laser. Tissue glue may also be used to close defects in the ovary following ovariotomy.
II. Basic Technology
Position of the patient
The patient should be anesthetized using muscle relaxants, endotracheal intubation and intermittent positive pressure respiration. The anesthetist should continuously monitor the patient&#;s heart rate, blood pressure and blood gases. It is common practice to place the patient in a modified lithotomy position with the legs flexed to 45. However, it is better to abduct the legs without flexion. This allows an assistant to manipulate the uterus and does not interfere with the use of ancillary instruments. There should be a 15 degree Trendelenberg tilt to allow the bowel to be lifted out of the pelvic cavity. The tilt may have to be steeper if more complex surgical procedures become necessary. The patient&#;s buttocks should protrude over the end of the operating table which should have non-slip mattress to prevent her sliding cephalic on the table.
Preparation for Laparoscopy
The operating room nurse should have available all the basic laparoscopy instruments and also those for operative laparoscopy and laparotomy. The surgeon should cleanse the abdomen with a suitable antiseptic solution, paying particular attention to the umbilicus. At the same time the assistant should cleanse, catheterize the bladder and apply a tenaculum to the cervix to manipulate the uterus.
Insertion of Pneumoperitoneum
The surgeon should first check the patency of the Veress needle and ensure that the sprig mechanism is functioning. A small incision should be made in the base of the umbilicus and the needle inserted while the abdominal wall is lifted with the other hand. This prevents damage to the underlying viscera and the major vessels. The needle should be held by the milled ring and should be heard to give two clicks as it passes through the fascia and then the peritoneum. The insertion should always be at 90 degree to the surface through the deepest part of umbilicus. The abdominal wall is at its thinnest at that point and the peritoneum is firmly applied to it. It will not peel off with pressure from the needle and predispose to an extraperitoneal insufflation of gas. Insertion of the needle at another site may be necessary if there are adhesions beneath the umbilicus but it should be remembered that the abdominal wall at these sites may be thicker and the peritoneum more loosely applied.
The position of the tip of the Veress needle should be checked by the aspiration test. A 20 ml syringe with normal saline is attached to the Veress needle and aspirated to ensure that the needle is not in bowel or major vessel. About 10 ml of saline should then be injected rapidly and aspirated again. If the needle is correctly sited the saline will be distributed between loops of bowel and no fluid will be withdrawn. Alternatively the test may be performed by attaching an empty syringe to the Veress needle, aspirating to make sure no faeces or blood is withdrawn and then injecting 20ml of air and repeating the aspiration. If the needle is sited correctly, noting will be withdrawn but, if the needle is in the wrong position, gas or brown or red fluid will appear.
Transumbilical insertion of the needle may be difficult or dangerous if the patient is grossly obese or has scars on the abdominal wall from previous operations. In this case the pneumoperitoneum may be introduced through the posterior fornix using a tenaculum to pull the cervix forwards which puts the uterosacral ligaments and the floor of the pouch of Douglas on tension.
The pneumoperitoneum is formed by introducing 1-2 litres of carbon dioxide (CO2) at a rate of 11/min. Higher flow rates should only be sued under direct vision after the laparoscope has been inserted. When the pneumoperitoneum is complete, the peritoneal cavity should be tested for adhesions using the sounding test. This is performed by attaching an intravenous needle to the 20ml syringe which should now be half filled with saline. The pneumoperitoneum should be explored below the umbilicus at several points. The presence of space is confirmed by the ability to aspirate gas bubbles and its depth may be estimated by the length to which the needle can be inserted and gas aspirated. Only then should the primary trocar and cannula be inserted.
Insertion of the Laparoscope
During insertion of the primary trocar and cannula the upper abdominal wall should be compressed by the free hand to make the lower abdominal wall tense. The trocar and cannula may then be safely inserted along a zigzag path using the extended fore finger to prevent sudden and deep penetration. If the line of insertion is straight there may be risk of herniation of omentum of bowel through the incision. It is always necessary to use secondary portals of entry through which ancillary instruments can be introduced to allow organs to be retraced or lifted so that all their aspects may be examined. The ancillary instrument may be a long Veress needle, a probe or a pair of forceps. The secondary trocar and cannula must always be inserted under direct vision. They may be introduced within the safety triangle whose base is formed by the bladder and whose apex is the umbilicus while the obliterated umbilical arteries form its lateral walls. Alternatively they may be inserted lateral to the artery which should always be identified by direct vision through the laparoscope or by trans illuminating the abdominal wall.
Inspection of the abdominal organs
Inspection of the abdominal organs must always be performed in a systematic manner. The inspection should start with cecum and appendix and proceed upwards on the right side to the ascending colon until the hepatic flexure is reached. The right lobe of the liver and gall bladder should now be inspected. It may be necessary to reverse the Trendelenberg tilt to allow gas to flow to the upper abdomen to obtain a clear view of the liver. The telescope should then be withdrawn a little to allow it to pass the ligamentum falciparum and reach the left lobe of the liver. The anterior aspect of the stomach should be inspected but the spleen cannot normally be seen without retracting the stomach which is rarely indicated. Finally, the descending colon should be inspected as far as the sigmoid colon. It should be remembered that there are normally adhesions between the descending colon and the pelvic side wall and, sometimes, also to the left round ligament. These are physiologic and need not be disturbed unless better access to the left adnexa is needed. The diagnosis of diverticular disease may be confirmed by palpating the consistency of the bowel with the probe or forceps. The altered consistency of the bowel is often obvious.
Inspection of the pelvic organs
The pelvic organs may be examined when inspection of the upper abdomen is complete. Detailed inspection is only possible by manipulating the uterus to bring all its aspects into view and by using an ancillary probe or forceps to aid the full examination of the fallopian tubes and ovaries. It is impossible to perform a complete examination of the pelvic organs suing a single puncture technique. The examination must be systematic. It is usual to commence with the uterus and proceed in a clockwise direction.
The uterus should first be examined starting with the fundus followed by the anterior and posterior walls. The size and shape of the uterus should be noted as should the presence of intramural or sub serous fibroids and adhesions which may limit uterine mobility.
The anterior cul de sac should next be explored. The bladder peritoneum is a frequent site of peritoneal endometriosis and occasionally adhesion of the bladder to the uterus may be seen resulting form previous surgery. The round ligament should next be seen followed by inspection of the tube in its full length form cornu to fimbriae. It is nearly always necessary to lift the tube with a probe or forceps to see the fimbriae. This should always be done as there may be adhesions or phimosis even if the tube is patent. Peritubal adhesions and adhesions between the tube and ovary must be looked for as they may interfere with its motility and result in infertility. Mild adhesions may be lysed with electrosurgery, scissors or laser. If there are more extensive adhesions it may be necessary to investigate tubal morphology further by salpingoscopy to decide on the optimum form of treatment.
When the tube has been inspected, attention should turn to the ovary. The ovary may be lifted by a second instrument placed under the round ligament of the ovary or, less commonly, under the infundibulo-pelvic ligament. Detailed inspection of the ovary should also include seeking evidence of its function as well as signs of disease such as endometriosis.
The broad ligament may be the site of endometriosis as may the uterosacral ligaments or the floor of the pouch of Douglas.
The examination should now continue in a clockwise direction to inspect the left side of the pelvis and will be complete when the anterior cul de sac has been reached again. Failure to use a systematic approach such as this is a common cause of significant pathology being missed.
World Laparoscopy Hospital, Gurugram, NCR Delhi, www.laparoscopyhospital.com
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