- Equipment in Laparoscopic Surgery
- Peritoneal Access in Laparoscopy
- Port Placement in Laparoscopy
“Give me six hours to chop down a tree and I will spend the first four sharpening the axe.”
Abraham Lincoln
“Before a new instrument is used, the surgeon should know and test it. It is always better to test a device before a procedure than during it!”
INTRODUCTION
Over the last 30 years, laparoscopic procedures have become standard in most surgical diseases. The rise of abdominal and pelvic laparoscopic surgery has been a true revolution in medical practice. The concept of minimally invasive approach, with all its advantages such as quicker recovery, shorter hospital stay and a far superior aesthetic results has been gaining more and more supporters among the international surgical community. The old paradigm that a big incision meant a big surgeon has dramatically changed.
The equipment and instruments for performing these minimally access procedures has, over the years, greatly improved. Following the surgeons’ demands, the increasing investment and research on better tools have provided more sophisticated and efficient equipment that offers lower risk and thus higher safety to our patients.
An organized and well-equipped operating room is essential for successful laparoscopy. The surgical team and the operating room staff should be familiar with the instruments and their functions. If they are not aware of an instrument's mechanism of action, it can interfere with surgery progression, increasing not only risks for patients but also surgeon's anxiety and fatigue. Each instrument should be inspected periodically. Scissors, graspers, trocars, trocar sleeves are checked for loose or broken tips, even if the same instruments were used during a previous procedure.
One of the most important benefits of laparoscopy is the magnified vision offered by the optics and high definition cameras and thus better identifies anatomical structures and dissection plans. This improved image often permits a more precise surgical gesture, better hemostasis and probably less postoperative adhesions.
Almost all instruments available for laparotomy are now available in a specialized form for laparoscopy. Instruments and devices that are used in laparoscopy include the laparoscope (camera), trocars and port devices, instruments for dissection, hemostasis and ultrasound. Laparoscopic instruments attempt to reproduce the effects of conventional laparotomic instruments: Grasping, dissecting, cutting and coagulation.
LAPAROSCOPY VERSUS OPEN SURGERY
Operative laparoscopy requires an advanced degree of technical skills and training. The smaller size incisions and instruments implicate a huge degree of precision only dealt by imaging systems of high magnification.
In spite of the same final objective, we have to distinguish the laparoscopic field from the open surgery 4field. Contrary to open surgery where surgeons have a direct view and manually manipulate and palpate tissues during the operation, the challenge in laparoscopy is the absence of stereoscopic vision and the need of transpositioning the movement of surgeons’ hand through a long small diameter trocar creating one or more output functions at the distal part of body cavity.
Some of the specificities of laparoscopic surgery are:
- Limited field of vision controlled by an assistant: Surgeons need an increased cognitive and physical load to perform the surgery (i.e. the instruments may intermittently disappear from the surgeon's vision while manipulating structures).
- Reduced depth perception: The monitors used in laparoscopic surgery filter three-dimensional cues from the operative field such as interposition or overlap, lighting, outline and texture.1 The effect of reduction in depth cues can be inferred from performance differences under different viewing conditions, as 3D video systems that restore stereoscopic vision are currently available.
- Impaired hand-eye coordination: The main variables are the location of the monitor, degree of amplification, mirrored movement and misorientation.2
- Motion limitation: The trocar restricts movement by acting as invariant points.3 The surgeon's dexterity is affected because the range of motion is reduced to four degrees of freedom compared to six needed to perform free motion. This movement restriction leads to increased physical discomfort.
- Reduction of haptic feedback: The role of haptic feedback is of special interest because it is used in important decision-making scenarios such as the discrimination of healthy versus abnormal tissues, identification of organs and motor control. In laparoscopic surgery, it is reduced but not absent as in robotic surgery.4–5
- Vision is dependent on the cleanliness of laparoscopic optic, intra-abdominal smoke and light absorption: Irrigation, blood, organic fluids, intra-abdominal pressure and smoke can impair surgeon vision. The irrigation of the operative field should be minimal as the mixture of blood with serum alters light absorption creating difficulties to discriminate structures and surgical planes. Equilibrium is necessary between smoke evacuation and pneumoperitoneum preservation.
IMAGING DEVICES
Minimally invasive surgery resulted from the introduction of new imaging devices to look at internal organs through pericentimetric or shorter incisions. Surgical scopes are recognized as very old medical instruments conceived many centuries ago when simple hollow tubes were used to observe intracorporeal cavities. Philip Bozzini in 1805 used the first illuminated scope consisted in a viewing tube with a series of mirrors which reflected light from a burning wax candle. However, only in the 20th century, a light scope was used to perform a diagnostic laparoscopy and only after the success obtained with laparoscopic cholecystectomies (1986), the medical industry started to develop better imaging and optical devices.6
Although the skepticism of some during the years, today we are facing a rapid advancement of minimally invasive surgery in different disciplines and pathologies, and in parallel, new imaging devices are appearing. The surgeon must be familiar with these developments.
Laparoscope: Traditionally, the laparoscope is a rigid endoscope which is made of an outer ring of optical fibers, used to transmit light into the abdominal and pelvic cavity and an inner core of rod lenses via which the illuminated operative field is captured by a camera. Digital imaging chips located within the camera allow the image from the scope to be transmitted to an external display.
Various different types of laparoscope are available, specified in terms of overall length, number of rods, diameter and angle of view. The diameter of laparoscopes varies from 3 mm to 12 mm and the objective located at the distal end offers an angle of view from 0 to 120 degrees. The brightness of the image is lower in thinner scopes, due to less light transmission through the central channel lenses. However, with the improvement in the optical fiber technology, even laparoscopes with 3 mm of diameter are able to produce brighter and clearer images. The “angle of view” enables the operator to see objects that might otherwise be out of camera view. A 30° telescope provides a total field of view of 152° enabling the visualization of the anterior abdominal wall and working around masses or within deeper spaces. A 0° telescope provides a field of view of 76°, but offers a panoramic view and more usual perspective (Fig. 1). There is a laparoscope model that has the possibility of changing the view angle from 0° to 120° (Fig. 2). Flexible tip laparoscopes are also available.
In gynecology, telescopes without instrument channels are used in the majority of cases, as they give a better overview and offer better image resolution. However, in some cases, it may be useful to use telescopes with an integrated instrument channel (Fig. 3). These laparoscopes are generally 0° straightforward scopes. The diameter of the instrument channel is 5–7 mm; thus, a correspondingly large instrument can be inserted. CO2 laser can also be connected to this laparoscope.5
In gynecology, a good application for these instruments is in performing laparoscopic sterilization. In addition, tissue fragments or biopsy specimens can also be extracted with the aid of a grasping forceps introduced through the telescope's instrument channel. On other hand, a disadvantage of using telescopes with instrument channels is the deterioration in image quality. This is due to the lower light intensity that can be picked up by the video camera, when compared with telescopes that do not have an instrument channel.
The light sources and light cables: No light, no laparoscopy! The light is transmitted from a light source (located separately off the patient table) to the operative field through a light cable and the fiber bundle in the laparoscope. High-intensity light is created with bulbs of halogen gas, xenon gas or mercury vapor. The bulbs are available in different potencies (150 and 300 Watts) and should be chosen based on the type of procedure being performed.
Nowadays, there are two types of light cables available: fiberoptic or liquid crystal gel cables. Fiberoptic cables are made up of a bundle of optical fiber glass thread swaged at both ends. Light transmission occurs by total internal reflection and is improved with an increasing number of light fibers and increased diameter cable. These cables offer little light loss but are less durable than the liquid-filled light guide cables, because, some optical fibers break with continuous usage. However, the liquid crystal gel cables are made more rigid by a metal sheath, which makes them less flexible and more difficult to maintain and store.
Laparoscopic Camera
A high quality image is essential to perform the procedure safely. The laparoscopic camera has undergone some of the biggest changes in the last decade (Fig. 4). Most endoscopic surgery is being done now with high-definition technology. With this improved image quality cameras, the surgeon can more readily identify the relevant anatomy. Nowadays, systems that produce three-dimensional images are currently under development and seem to facilitate surgical performance.7
Video Monitors
The sizes of the screen vary. To accommodate high-definition cameras, the medical industry has adopted the flat-panel monitors whose resolution determines a better image. Some monitors include sterile touchscreen functionality, offering the surgeon control over the entire imaging system via the monitor.
Video Recording Systems
The video recording systems document and record the performed procedures. They are of paramount importance for scientific and educational purposes.
CO2 GAS INSUFFLATOR
The pneumoperitoneum offers the surgical field and the access for the procedure itself. Conventional gas insufflators are sufficient for a purely diagnostic laparoscopy. However, in surgical laparoscopies performed today, accurate pressure control insufflators are necessary to compensate considerable volume losses that occur, for example due to frequent suction of irrigation solutions using high-performance irrigation-aspiration units. High-flow CO2 insufflators are a basic prerequisite for surgical laparoscopy, as they monitor intra-abdominal pressure constantly and halt the flow immediately when the set intra-abdominal pressure is reached. Electronically controlled insufflators have become the preferred choice in this respect. The insufflator's display indicates all the vital information that is needed for the surgeon (Fig. 5):
- Patient's intra-abdominal pressure (should not exceed a value of 15 mm Hg)
- Rate of inflow of the gas
- Volume of CO2 insufflated
- Gas reserve.
When the pressurized CO2 expands, it cools down and has the potential to reduce the body temperature of the patient. Some insufflators are equipped with facilities to heat the CO2 before its passage into the abdomen. In order to avoid the disadvantages of CO2 insufflation, gasless laparoscopy could be an alternative.
PORTS OF ENTRANCE IN ABDOMINAL CAVITY
Veress Needle
Disposable and reusable Veress needles for creating pneumoperitoneum are available. Veress needle is used to create the initial pneumoperitoneum. A trocar can be introduced safely because the distance from the abdominal wall to the organs is increased. The Veress needle technique is the most widely practiced method to access the peritoneal cavity. Veress needle compromises two components—an outer hollow needle with a sharp beveled edge, and an inner, spring-loaded, retractable blunt obturator with the stop position beyond the tip of the hollow needle. Once the peritoneal cavity is entered, the blunt obturator is just forwarded by the spring-force and protrudes beyond the tip of the hollow needle, thus preventing from iatrogenic visceral and vascular injuries.
The reusable type should be preferred to reduce the costs of laparoscopic surgery. Verress needles are available in three lengths: 80 mm, 100 mm and 120 mm. In the thin patients, with scaphoid abdomen, an 80 mm Verress needle should be used. In obese patients, a 120 mm Veress needle is preferred. Disposable needles do not require cleaning or sterilization procedures. The Veress needle must be kept in perfect condition to ensure that the mandarin slides easily into the protective sleeve. The surgeon must have full knowledge of all safety features of the mandarin. The Verress needle should be held between the thumb and the index finger during insertion. When the needle is inserted through the abdominal wall, passage through the fascia into the peritoneal cavity can be recognized as a tactile “popping” sensation.
Trocars
The trocars establish a small interface between the surgeon and the surgical field. The trocars are the accesses through which the surgeon goes inside the abdominal cavity, establishing a shaft and support for different instruments.7
In the time of cost reduction, the use of disposable trocars is clearly diminishing. There are very high quality reusable trocars in the market that avoid the use of disposable ones (Figs 6A and B).
In general, trocars with various diameters are used in surgical endoscopy. The standard sizes are 3.5, 5.5, 11, 12, 15 and 22 mm but there has been a recent trend towards the use of smaller trocars, even for advanced procedures.
All trocars have a flapper or trumpet valve. Spherical and flap valves allow a quickly change of operating instruments, as this change can be carried out without activating the valve mechanism. Trumpet valves are mostly found in telescope trocars. The telescope is protected from contamination by tissue and blood particles during insertion by pressing the trumpet valve.
Trocars tips may be sharp or blunt, radially expanding, shielded and/or transparent. Sharp, pyramidal trocar tips can be positioned relatively easily; however, the sharp edges can sometimes damage smaller blood vessels and other organs. By using spherical, blunt, trocar tips, the blood vessels are pushed aside and protected to a large degree. Sometimes, however, greater pressure has to be exerted during insertion. Since the skin incision for the auxiliary puncture is carried out under transillumination and the puncture itself is in full view, the choice of trocar tip here can be regarded as being of secondary importance. Better protection to prevent the trocar slipping out of the intraperitoneal space is provided by sheaths with screw threading. However, these cause increased trauma to both the abdominal wall and the peritoneum. Trocar reducers may facilitate the surgery in case you use smaller instruments.
INSTRUMENTS
Dissection and grasping instruments: Dissect means “methodically cut up (a body or plant) in order to study its internal parts”. Dissection is probably the finest part of a surgery. Almost all standard instruments available for laparotomy are available in a specialized form to fit through an endoscopic 3–20 mm port.
Grasping forceps have been designed for tissue manipulation, and may be locking (ratcheted) and no locking (nonratcheted). Some forceps are broad and flat, while others are finer and made for delicate tissue handling (Figs 7A and B).
Atraumatic stabilization of structures is achieved by fine grasping forceps multiserrated and with a round tip. With an atraumatic forceps the surgeon is able to expose and perform the countertraction needed to dissect and to suture. For example, prehension of the Fallopian tube or the ureter. A Babcock-type atraumatic grasper with a ratcheted scissors handle can be particularly useful in handling the mesentery or adnexal structures.
Toothed forceps (claw forceps) are used to grasp and liberate solid organs. In a laparoscopic cyst extirpation, to fix the ovary properly and remove the cystic capsule, it is crucial strong grasping forceps. Forceps with pointed ends are used for tissue dissection and surgical plane development.
Dissecting and grasping instruments are available in either reusable or disposable forms. The disposable instruments are typically less cost-effective, although they have the advantage of being available (when properly stocked), and the cutting edges are always sharp, whereas no disposable instruments may be in the process of cleaning and resterilization, particularly where many laparoscopic surgeries are performed.8
Most of the dissectors and graspers have the availability of electrosurgery connection.
Biopsy forceps: They are used during diagnostic laparoscopy to sample suspected endometriosis implants, or in ovarian suspicious malignancy (before chemotherapy or during second-look laparoscopy).
Scissors: These instruments may be straight, curved or hooked. Delicate dissection can be carried out with straight scissors. Curved scissors, in general, have the same features as for straight scissors. In some cases, they are easier to dissect with, because the curvature changes the viewing angle. Hook scissors are particularly suitable for transecting ligature fibers and for tissue transection (Fig. 8). Scissors can be used to adhesiolysis, section of coagulated tissue and sutures cutting. Some have an electrical adapter so they can be combined with unipolar or bipolar electrocoagulation.
Coagulation instruments: Most devices used for coagulation during operative laparoscopy are adapted from open surgery. More details about electrosurgery were described in the chapter “Principals and use of electrosurgery in laparoscopy”.
Concerning monopolar instruments there are different tips available (Fig. 9A). There is a monopolar high-frequency needle that can be retracted into the sheath (Fig. 9B). Also a vast armamentarium of bipolar forceps with various tips is seen with a coagulating probe (Fig. 10).
Needle holders: The figure below shows 5 mm needle holders. These instruments are essential to perform suture and knots. There are different types of needle holders. They may have a straight or curved handle, as well as straight and curved tips. The co-axial types with a locking system are preferred to the pistol type needle holders (Figs 11A and B). There are also automatic needle holders that after being charged, put the needle in a 90° angle. In extracorporeal sutures, the aim is to apply tension under a controlled way (myomectomy, promontofixation, vaginal cuff closure), a knot pusher is needful.
Suture passer devices: There are various types of sutures passers available for closure of ports and transfacial ligature (Fig. 12). The thread passer has a side slit to carry the thread into the peritoneal cavity on one side to the trocar. Once the thread is in the peritoneal cavity, the instrument is introduced on the other fascia side and the thread is pulled out closing the fascia defect caused, for example, by the trocar insertion. This procedure should be performed under laparoscopic view and guidance.
Intestinal probe: The intestinal probe is used to push back the bowel in order to achieve a good view. It may be important for endometriosis surgery to expose the rectum or in sacrocolpopexy to deviate laterally the rectum and sigmoid during the procedure.9
Figs 9A and B: (A) Monopolar instruments; (B) The monopolar high-frequency needle (Karl Storz): The tip of the needle can be retracted into the sheath
Vaginal probe: It is very useful for exposing the vagina mainly during deep endometriosis and prolapse surgeries (Fig. 13).
Myomas holder: During a laparoscopic myomectomy, it is difficult to stabilize a smooth, hard fibroid. Myoma screws (5 mm and 10 mm) allow the surgeon to maneuver the myoma and apply traction with improved exposition and access (Figs 14A and B). Another alternative for myoma fixation is the use of a strong tenaculum offering you more mobility in the myoma traction points.
Tissue removal: In the past, laparoscopic surgeons were faced with the difficult problem of tissue extraction, and were often obliged to perform a suprapubic mini-laparotomy or a transvaginal extraction.
There are several good alternatives available for the surgeon to remove large volumes of tissue without increasing the size of the laparoscopic access incisions. Morcellators grasp, core and cut the tissue to be removed into small pieces. These fragments are forced into the hollow part of the instrument. Manual and automatic morcellators are available. Steiner developed the electromechanical morcellator, consisting of a motor-driven cutting tube. The speed can be selected in three stages. It is possible, with the aid of this morcellator, to extract even large amounts of tissue from the abdomen, using the size 11 trocar, in a short period of time. With 12 mm and 15 mm trocars, large quantities of tissue can be extracted in this way within a few minutes.
Automatic morcellators are more expensive but are very effective and save time when large amounts of tissue need to be removed (Figs 15A and B). It is obligatory to observe the tissue that will be removed from the moment it is divided from other tissues to its delivery through the abdominal wall regardless of whether or not it is removed in a tissue bag to prevent injury to adjacent tissues. Because of the good cutting quality of the rotating morcellator, the tissue structure is minimally damaged. It also enables a reliable histological examination to be carried out.
Figs 16A and C: (A and B) Suction-irrigation devices; (C) The GORDTS/CAMPO—coagulating suction and irrigation cannula by Karl Storz
Tissue bags can be used to isolate tissue (e.g. tumor, infected appendix) prior to removal with or without morcellation. The tissue bag can be removed through a secondary port site or through the infraumbilical port once the camera has been removed. For some (e.g. appendectomy), but not all types of laparoscopic surgeries, the use of a tissue bag may decrease the risk of surgical site infection or oncological dissemination. The tissue bag can also be removed through the cul-de-sac after a culdotomy (in alternative to a trocar port size enlargement).
Irrigation-suction: During diagnostic and surgical laparoscopy, it is commonly necessary to drain fluids and irrigate wound surfaces until they are clean and can be viewed adequately. Irrigation is used to clear debris or blood when bleeding is encountered, if a strong irrigation pressure is applied it can be helpful to clearly identify the origin of a bleeding. Some surgical teams defend that irrigation can also be used for hydrodissection and creation of tissue planes. On other hand, many surgeons say that irrigation should be avoided because it may interfere with the CO2 pneumodissection of the retroperitoneal spaces. It is important that these solutions are used at body temperature.
Suction is performed either by means of a central vacuum supply system or with an additional suction pump that works usually better. Different laparoscopic suction instruments have been designed to remove irrigation fluid or intraperitoneal air and smoke. Combination suction/irrigation devices are also available (Figs 16A and B). A larger 10 mm suction-irrigation instrument is ideal for removing blood clots when brisk bleeding is encountered (e.g. severe hemoperitoneum after an ectopic pregnancy rupture).
In the market, there is available a suction-irrigation device with a bipolar current tip that may be useful in case of ovarian endometriomas and deep endometriosis.12
It is a more versatile device allowing blunt dissection, coagulation, irrigation and fluids suction, simultaneously (Fig. 16C).
Uterine manipulators: Safe, effective endoscopy, requires adequate mobilization and stabilization of the uterus and associated organs. Various combinations of uterine sounds, cannulas, and dilators are available (Figs 17A to C). They are very useful for the uterus exposition during procedures like hysterectomy, myomectomy, adnexal surgery and endometriosis. Some surgeons even say that “…if an uterine manipulator is properly used, it makes half of the hysterectomy…”
REFERENCES
- Shah J, Buckley D, Frisby J, et al. Depth cue reliance in surgeons and medical students. Surg Endosc. 2003;17(9):1472–4.
- Breedveld P, Wentink M. Eye-hand coordination in laparoscopy—an overview of experiments and supporting aids. Minim Invasive Ther Allied Technol. 2001;10(3):155–62.
- Schurr MO, Breitwieser H, Melzer A, et al. Experimental telemanipulation in endoscopic surgery. Surg Laparosc Endosc. 1996;6(3):167–75.
- Bholat OS, Haluck RS, Murray WB, et al. Tactile feedback is present during minimally invasive surgery. J Am Coll Surg. 1999;189(4):349–55.
- Brydges R, Carnahan H, Dubrowski A. Surface exploration using laparoscopic surgical instruments: The perception of surface roughness. Ergonomics. 2005;48(7):874–94.
- Reynolds W Jr. The first laparoscopic cholecystectomy. JSLS. 2001;5(1):89–94.
- Cicione A, Autorino R, Breda A, et al. Three-dimensional vs standard laparoscopy: Comparative assessment using a validated program for laparoscopic urologic skills. Urology. 2013;82(6):1444–50.