Light source and light lead

One of the great advantages of endoscopic over open surgery is the visualization of the anatomy and so adequate illumination is vital. Light sources have evolved from the initial platinum wire loop to fibreoptics and the rod‐lens system. Illumination is now usually achieved using an incandescent bulb and heat generated is in the form of infrared light. A condensing lens concentrates light from the bulb into a narrow beam at the cable input and the light is then transmitted to the laparoscope via a gel or fibre cable. High‐definition cameras require a higher performance light source because they have reduced sensitivity given the smaller pixel size.

Camera and monitor system

The camera system consists of three key components: the camera head, the camera control unit and the monitor to visualize the image. The image is captured as a digital signal from a distal mounted lens and transmitted through a rod‐lens system to an ocular mounted lens which magnifies it and the image is visualized on a monitor.

Current three‐chip cameras consist of a goal lens, a prism assembly and three sensors for acquiring the primary colours, providing more natural colour reproduction than earlier technologies. Video laparoscopes are now also available where the chips are built into the end of the optic, capturing the image at the tip of the laparoscope and improving image quality and accuracy. Three‐dimensional imaging provides greater depth perception [2], although the technology has yet to achieve widespread popularity. A video cable transmits the digital image data between the camera head, camera control unit, and monitor. Flat screens in high definition have superseded earlier monitors and provide a much superior image. Narrow‐band imaging is a recent innovation, which uses a specific narrow wavelength to change the normal colour contrasts of the laparoscopic image.

Energy modalities

Electrosurgery, often referred to as diathermy, has been used in surgery for over 100 years and has become an integral component of both hysteroscopic and laparoscopic surgery. Laparoscopic energy modalities are essential for dissection, ligation and haemostasis [3]. Monopolar, bipolar, ultrasonic and advanced bipolar energy sources are currently used. Electrosurgical cutting depends on electrical arcing between the electrode and tissue resulting in vaporization and cell explosion, whereas coagulation is achieved with the electrode in contact with tissue causing heating and coagulation.

Monopolar electrosurgery delivers an electrical current via one active electrode that disperses through the patient to an attached passive return electrode. The advantages of monopolar diathermy include the ability to chose pure or mix/blend currents so that cutting and dissection can be achieved while providing haemostasis and coagulation. Disadvantages include (i) unintentional thermal injury due to thermal spread and unintentional visceral contact with active or heated electrodes, (ii) direct or capacitive coupling and (iii) improper placement of the return electrode or contact with volatile substances such as cleaning fluids.

Bipolar electrosurgery differs from monopolar in that the current travels only between the two active prongs of the electrodes. Therefore, the energy travels only through the target tissue and not through the patient. Both electrodes are of equal size, producing similar temperature changes at both ends, allowing for targeted desiccation at lower temperatures. This translates to a lower risk of collateral damage. The advantages of bipolar electrosurgery include a virtually eliminated chance of alternate site burns or direct and capacitative coupling. As no return electrode is required, the risk of a dispersive electrode burn is eradicated. The disadvantage of bipolar electrosurgery is its inability to cut tissue.

Advanced bipolar electrosurgery refers to devices that have been developed to more precisely manage delivery of bipolar electrical energy, providing consistent and rapid tissue and blood vessel sealing. They also incorporate a mechanical cutting blade at the electrode site. This blade is deployed to provide bloodless cutting after very effective desiccation of the tissue (Fig. 37.1).

Ultrasonic energy can also be used to dissect, cut and coagulate tissue, avoiding the potential dangers associated with electrical currents (Fig. 37.2). Mechanical energy is generated from rapid vibrations of a blade or shears at the tip of the instrument, causing water to evaporate from the tissues at a low temperature. This desiccates the tissues and allows precise cutting and dissection. The other mechanism it uses is stretching of the tissue by the blade edge, causing friction and generating heat, cutting the tissue. The advantage of the ultrasonic scalpels compared with electrosurgery is the reduction in tissue charring, desiccation and spread of thermal energy, lowering the risk of inadvertent injury to other structures. Devices are now also available that combine both advanced bipolar electrosurgery with ultrasonic energy.

Advanced bipolar devices and ultrasonic energy appear to provide more rapid and bloodless operating compared with conventional electrosurgery. To date, studies have not demonstrated a significant difference in complication rate between devices but this may be due to a relatively low complication rate in gynaecological procedures [4,5]. However, there is a need for properly designed and powered comparative studies to guide surgeons regarding the most effective and safe modes of energy to use for specific operations.

Laser energy in minimal access gynaecological surgery has diminished with the advent of the newer, easier to use and cheaper energy modalities described here.

Photo and video documentation

The universal use of video cameras at endoscopic surgery lends itself to recording still images, short excerpts of procedures or even whole procedures. Photographs are clinical records that can be discussed with the patient as well as colleagues if a second opinion is sought. Video recordings are excellent for teaching, and can also be used for research, to measure performance and to assess new instruments and techniques. Review of recordings can also help with the understanding of operative complications and are increasingly useful with regard to complaints and negligence claims.

Hysteroscopes

Hysteroscopes can be rigid or flexible. The majority of gynaecologists use rigid hysteroscopes because the image tends to be superior, the equipment is more robust and it can be sterilized. Moreover, operative procedures can be undertaken using rigid hysteroscopes whereas flexible hysteroscopes are restricted to diagnosis. Rigid hysteroscopes generally have a Hopkins rod‐lens optical system whereas flexible and very narrow rigid hysteroscopes contain optical fibres.

Rigid hysteroscopes come in different sizes in terms of their outer diameter, 2.7, 2.9 and 4 mm being popular sizes. The distal lens can be straight or oblique, the most frequently used being 0° and 30° angles of view. Oblique lenses have the advantage of a wider field of view, enabling diagnosis and facilitating operative procedures as instrumentation can be visualized under higher magnification. Diagnostic procedures can be performed using a single outer sheath fitted around the optic to allow irrigation of fluid or gas distension media thereby achieving uterine distension. Continuous flow permits simultaneous irrigation/suction and tends to be used for surgery where removal of blood and tissue debris is necessary to maintain visualization within the uterine cavity. To achieve continuous flow, operative hysteroscopes have both inflow and outflow channels (inner sheath for inflow, outer sheath for outflow) in addition to a working channel which can accommodate miniature ancillary instruments. Most diagnostic and operative hysteroscopic set‐ups are less than 5.5 mm in outer diameter. Resectoscopes and tissue removal systems can be up to 9 mm in outer diameter.

Uterine distension

The uterine cavity is a potential space and has to be distended at relatively high pressure to afford a panoramic view. To achieve this, gas (CO₂), low‐viscosity fluids (e.g. normal saline, 5% dextrose, 1.5% glycine, 3% sorbitol, 5% mannitol) or high‐viscosity fluid (e.g. Hyskon, which is 32% dextran 70 in dextrose) can be used. Normal saline is most frequently used for diagnostic hysteroscopy, replacing the use of gaseous CO₂ media. The choice of fluid distension media for operative hysteroscopy depends on the type of instrumentation; physiological media, namely normal saline, should be preferred when using mechanical instruments. Resectoscopic electrosurgery traditionally required the use of electrolyte‐free solutions such as glycine, sorbitol or mannitol because they employed monopolar electrical circuits. Bipolar electrosurgery using miniature electrodes or conventionally sized resectoscopes are now widely available and these necessitate the use of electrolyte‐containing fluid distension media, i.e. normal saline which is safer as it minimizes the sequelae of inadvertent fluid overload and induced hypo‐osmolar hyponatraemia.

The pressure required to provide an adequate view of the uterine cavity depends on a number of factors, but tends to be around 100 mmHg (13.3 kPa). An enlarged non‐compliant uterus, leakage of distension medium through the cervix or excessive suction when using a continuous flow system will mean that a higher inflow pressure is required. The desired distension is achieved by using gravity, pressure bags or special hysteroscopic pumps, which can also more accurately monitor fluid balance, thereby reducing the risk of fluid overload.

Mechanical instruments

Miniature flexible or semi‐rigid mechanical instruments such as scissors, grasping and biopsy forceps can be used with operating sheaths for minor procedures such as target biopsy or polypectomy. These instruments tend to be fragile because of their size, typically 7 or 5 French gauge (3 Fr = 1 mm), so replacements should be available should they break. On the plus side, they are very unlikely to injure the patient.

Bipolar electrodes

The first miniature bipolar electrodes were introduced in the late 1990s; the Versapoint™ Bipolar Electrosurgery System (Ethicon, Somerville, NJ, USA) allows electrosurgical resection of structural anomalies such that they can be used for polypectomy, removal of small intra‐cavity fibroids and metroplasty. The 5 Fr Versapoint electrodes include the spring, twizzle and ball design (Fig. 37.3). Other bipolar electrodes are now available. As these electrodes are bipolar, physiological solutions such as normal saline and Hartmann’s solution can be used for uterine distension, but a dedicated electrosurgical generator is required. The flow of electricity is limited to the distal tip of the electrode with current circulating between the distal active and slightly more proximal passive return surfaces. The electrodes are versatile because they can be passed down the 5 Fr working channel of any standard operative hysteroscope.

Resectoscopes

Hysteroscopic resectoscopes are used to resect or ablate the endometrium and excise focal lesions such as polyps and fibroids, remove septa and lyse adhesions. Originally the resectoscopes used a monopolar electrode but advances in technology have led to the development of equally effective bipolar resectoscopes that have the safety advantage of using isotonic distension media with reduced risks of serious complications arising from fluid overload and induced hypervolaemic hyponatraemia.

The modern resectoscope consists of five components: the optic, handle mechanism, inflow and outflow sheaths and an electrode (Fig. 37.4). The handle mechanism can be active or passive in design; for hysteroscopy, a passive handle is preferable as it maintains the electrode inside the sheathing system out of view and out of harms way. A typical resectoscope has an outer diameter of 26 or 27 Fr (8.7–9 mm) and uses a 4‐mm oblique view optic. Narrower ‘mini’ resectoscopes are now also available although they are not established in routine practice [6]. The electrodes themselves come in different designs, but the cutting loop (for polypectomy, myomectomy and endometrial resection), rollerball or rollerbar (for endometrial ablation or tissue vaporization) and the knife electrode (for metroplasty) are the most popular.

Tissue removal systems

Tissue removal systems are the most recent technological advance in hysteroscopic surgery. They were developed to provide simultaneous mechanical cutting and tissue retrieval thereby maintaining better views during surgical procedures within the uterine cavity and avoiding the use of more hazardous thermal energy. A tissue removal system consists of a bespoke operating 0° hysteroscope with an operating channel that allows the insertion of a disposable cutting handpiece comprising two rotating hollow metal tubes which rotate and shave away the pathology being approximated. Each tube incorporates a small aperture or ‘window’ distally through which removed tissue is extracted by the application of external suction tubing; the removed tissue is then trapped in a tissue collector. A generator provides the electrical energy to rotate the mechanical tissue removal system. The first of these systems was the TruClear™ (Medtronic, Minneapolis, MN, USA) (Fig. 37.5), which has been followed by similar products from Hologic (Bedford, MA, USA) called Myosure™ and Karl Storz (Tuttlingen, Germany) called Intrauterine BIGATTI Shaver (IBS®). More recently, the Symphion™ (Boston Scientific, Natick, MA, USA) has been produced which combines a tissue removal system with bipolar radiofrequency energy.

Laparoscopes

Laparoscopes are built around a rod‐lens system that transmits images to the camera. Fibreoptic micro‐laparoscopes are also available but are more fragile and provide an inferior image. Laparoscopes come in a range of diameters (3–12 mm) and various angles of view (0–30°). The 10‐mm 0° laparoscope is most widely used in gynaecological surgery. The vast majority of gynaecologists prefer a multi‐puncture approach with instruments inserted through ancillary ports usually sited to facilitate triangulation and manoeuvrability. Ancillary port sites are usually 5–15 mm depending on the diameter of the instruments to be accommodated. More recently, miniature surgical instruments, typically with diameters of 3 mm or less, can be utilized with less scarring [7].

Veress needle

The Veress needle [8] is a spring‐loaded needle used to create a pneumoperitoneum at laparoscopy, most commonly inserted at the umbilicus. The Veress needle is usually inserted transabdominally, but in obese patients can be introduced through the uterine fundus or vagina [9]. It is available in reusable and disposable forms. For patients with suspected periumbilical adhesions or a previous umbilical hernia repair, Palmer’s point (left subcostal) entry should be performed. An alternative is open entry (Hassan’s technique) where the layers of the anterior abdominal wall are dissected through a small linear incision. This may reduce the incidence of major vessel injury though not bowel injury [10]. Optical entry techniques are also favoured by some surgeons and can be used before or after insufflation. They generally consist of a hollow transparent trocar in which is loaded a 0° laparoscope [11].

Trocars and cannulae

Trocars and cannulae act as conduits for the laparoscope and other instruments. They come in a variety of sizes depending on the diameter of the instrumentation to be accommodated, with 5 mm and 10–12 mm ports being the most commonly used. The older types of trocar are made of steel, are reusable and are sharp‐tipped. Now there are a host of disposable trocars and cannulae with modifications to optimize performance. A recent Cochrane review comparing visceral and vascular complications did not show any difference in incidence between trocar types [8]. Mini‐laparoscopy is performed through 3.5–5 mm ports and although visualization is not yet comparable to that of standard laparoscopy, it is satisfactory and this approach has the advantage of better cosmetic results and a lower incidence of postoperative pain or incisional hernias.

Laparo‐endoscopic single‐site surgery

Laparo‐endoscopic single‐site surgery (LESS) is the term coined for single incision laparoscopic surgery. This technique uses a single umbilical port that is adapted such that not only a laparoscope but additional operating instruments can be passed. Bespoke multi‐access ports are available with expandable retractors and even home‐made designs with a surgical glove attached to the port and instruments passed through small incisions in the ‘fingers’, which have been inflated by the CO₂ used to create the pneumoperitoneum. The potential advantages of LESS include a better cosmetic result due to a single scar, decreased risk of wound infection and a reduced risk of herniation. However, a meta‐analysis comparing LESS with multi‐port laparoscopy has not demonstrated any significant difference in operative outcomes, postoperative recovery, postoperative morbidity and patient satisfaction, operating time or cosmetic results [9].

Robotic laparoscopic surgery

Robotic‐assisted laparoscopic surgery has been utilized in gynaecology as an alternative to standard ‘straight stick’ laparoscopy. The da Vinci® surgical system (Intuitive Surgical Inc., Sunnyvale, CA, USA) consists of three components: the console, which allows the surgeon to control the robot remotely; the inSite® vision system, which provides a three‐dimensional image of the operative field via a 12‐mm laparoscope; and the patient side‐cart fitted with three to four robotic arms to control Endowrist® instruments. Robotic surgery may offer several advantages in gynaecology, including magnified three‐dimensional vision, wristed instruments that aid dexterity and precision, and less fatigue and reduced back and shoulder injuries for surgeons because they can operate sitting down at a console [12]. There remains a lack of robust randomized controlled trial data on robotic surgery compared with standard multi‐port laparoscopy and at present, in the absence of compelling evidence of improved effectiveness, the costs associated with robotic surgery for the most part remain prohibitive [13,14].

Laparoscopic insufflator

One of the great advantages of laparoscopy over open surgery is superior visualization of the anatomy. This is achieved by creating a CO₂ pneumoperitoneum. CO₂ is used because it is odourless, non‐combustible, cheap, colourless and rapidly eliminated from the systemic circulation. Insufflators control intra‐abdominal pressure rather than flow, and this should be set at 12–15 mmHg (1.6–2.0 kPa) during surgery; a higher pressure of up to 25 mmHg (3.3 kPa) is recommended during trocar entry as this has the effect of increasing the distance between any trocar being inserted and bowel or large blood vessels thereby, in theory at least, reducing the risk of injury [15].

Suction/irrigation pump

The provision of suction (negative pressure aspiration) and irrigation (instillation of fluid under pressure) helps maintain visualization within the operative field. A 5‐ or 10‐mm suction/irrigation cannula can be used to aspirate blood and clean the pelvis (and more accurately estimate blood loss during surgery), deflate ovarian cysts and aspirate blood during pelvic procedures such as ruptured ectopic pregnancies.

Ancillary instruments

Mechanical instruments

Typically, 5‐mm grasping forceps are used to grip tissue. They can be atraumatic, suitable for holding delicate structures such as fallopian tubes, bladder and bowel, or traumatic to ensure a firm grip of more robust tissue, such as when performing ovarian cystectomies (Fig. 37.6). Sharp curved laparoscopic scissors are the other essential ancillary instrument used to dissect tissues.

Specimen retrieval

Experimental minimally invasive laparoscopy

Percutaneous surgical systems consist of a less than 3‐mm laparoscopic shaft percutaneously inserted using a Veress‐like needle tip and then an interchangeable 5‐mm tool (e.g. scissors, graspers, irrigation systems) is inserted in place of the needle tip [16]. Tools such as monopolar scissors, graspers, hook and irrigation systems can be utilized [17]. Natural orifice transluminal endoscopic surgery (NOTES) describes a technique utilizing a natural body orifice for entry into the peritoneal cavity rather than percutaneously. The most common site of entry is the stomach but for gynaecologists the site of entry is the vaginal vault. Laparoscopic surgery can then be performed through this using flexible instruments and the vault can be sutured closed from the vaginal approach [18,19].

Hysteroscopy

While diagnostic hysteroscopy has become an outpatient procedure in most cases, with even minor operative procedures being done under local anaesthesia, more major surgery (e.g. hysteroscopic myomectomy for a sizeable submucous fibroid) usually requires general anaesthesia. It is best to have all the necessary equipment together on a surgical cart, with the monitor at a comfortable height and position for the operator (and patient if she is awake) (Fig. 37.7).

Laparoscopy

The set‐up for laparoscopy is more varied than for hysteroscopy partly because there tends to be more equipment and partly because laparoscopy is not ‘solo’ surgery but, as is the case with laparotomy, requires the help of assistants. Most gynaecologists prefer to use 0° optics and it is common for one of the assistants to stand on the contralateral side of the patient and control the laparoscope, leaving the lead surgeon free to operate with two hands (Fig. 37.8). However, ergonomically this set‐up is not ideal and so where the operating assistant is suitably experienced, the operator or assistant (whether standing adjacent or opposite the operator) can control the laparoscope and ancillary ports to cut, ligate, hold and retract tissue as well as irrigate, suck, suture and retrieve specimens.

Technique

The patient should positioned in lithotomy with the hips well flexed and the buttocks slightly over the edge of the table to allow unimpeded access irrespective of uterine position (Fig. 37.9). A ‘no touch’ vaginoscopic approach (Box 37.1) should be adopted as this is associated with reduced pain with no evidence of reduced feasibility or morbidity.