1、Laparoscopic InstrumentationPatrick S. LowryINTRODUCTIONLaparoscopic instrumentation continues to evolve towards smaller, more reliable, and betterergonomic devices, with a larger variety of choices. Since the first edition of this textbook, subtleimprovements are readily apparent in existing device
2、s as first-generation instruments progress towardslater-generation models. New technology exists to allow procedures to be performed with fewer com-plications. Combined with refinements in techniques, new and improved instrumentation providesurologic surgeons the opportunity to safely perform more c
3、hallenging procedures by a laparoscopicapproach.CAMERA SYSTEMSCamera systems still have three integral parts: the camera head, the camera system control unit, andthe monitor. These systems have progressed from analog to digital to advanced applications of digitaltechnology (1).Most cameras attach to
4、 the end of the scope to capture the image coming through the lens. Thisimage is then captured as a digital signal and transferred by the control unit to the monitor. Newermonitors are flat screen panels. Early flat screens did not provide adequate imaging, but by increasingpixel concentration and s
5、ubsequently progressing into high-definition (HD) imaging, current monitorssurpass previously available picture quality. To achieve this, significant improvement was required inthe transfer of the digital signal to the monitor. Early-generation digital units suffered from a millisec-ond lag time bet
6、ween what was performed surgically and what was seen on the screen. This delay canbe distracting, due to the subtle disconnect between surgeon and image. The current units process thesignal to an image with increased speed, making any delay imperceptible.Some systems, videolaparoscopes, employ a sin
7、gle camera/scope unit. These units have a chargedcoupled device (CCD), which is a minute digital chip attached to the tip of the scope (2). Their advan-tage is improved picture clarity, due to the capability to capture the picture digitally at the scope tip,rather than capturing the image of the pic
8、ture after it has passed through the lens of the scope. Sincethe picture travels via wire instead of through a lens, some scopes have been developed with the capa-bility to flex at the tip (see “Scopes”). Additionally, HD videolaparoscopes are now being released,further enhancing the picture clarity
9、. Regarding HD systems, one must realize that to visualize a trueHD image, the camera, the camera system control unit, and the monitor must all be HD capable.From: Current Clinical Urology: Essential Urologic LaparoscopyEdited by: S. Y. Nakada and S. P. Hedican, DOI 10.1007/978-1-60327-820-1_2C Huma
10、na Press, a part of Springer Science+Business Media, LLC 2010910 LowryA 3D viewing system (Viking Systems) gives the surgeon a 3D view of the operative field witheither standard or HD technology (3). This unit requires a type of helmet to be worn by the surgeon inorder to visualize the 3D picture.La
11、paroscopy has enjoyed rapid advancements in picture quality. Interestingly, although the imagesare significantly improved, as are costs, surgical outcome is unlikely to be affected.SCOPESBasic laparoscopes are 5 or 10mm in diameter. The lens at the tip of the scope is generally fixedat 0, 30, or 45
12、of angulation. Larger scopes present a better image with a larger field of view, butsmaller scopes may be used through smaller, less invasive, trocars. Videolaparoscopes may employ adeflectable tip (Fig. 1, Olympus), allowing the same scope to be used from 0 to 90 without the needto change scopes. T
13、he flexible tip allows significant flexibility, yet the camera holder must remaincognizant of the scope tip and keep the surgeon aware of the angle in use. A 10mm scope with atraditional lens that rotates on an axis from 0 to 45 is currently in the prototype stage of development(Storz).Fig. 1. 5-mm
14、Videolaparoscope with flexible tip (Olympus). Insets show scope flexed at 0 and 90.Three-dimensional scopes, such as those used in the Viking or DaVinci systems, utilize two parallellenses in the scope. The tips of these are fixed in a slightly different orientation, which provides 3Dviewing when se
15、en through the appropriate viewing system (4).Laparoscope fogging may be kept to a minimum by keeping the scopes at body temperature. Whennot in use, the end of the scope should be submerged in a heating thermos or water bath. Alternatively,a disposable heating pad (Stryker) may be wrapped around th
16、e end of the scope to keep it at theappropriate temperature. Additionally, anti-fogging solution should be used at the tip of the scope.Laparoscopic Instrumentation 11INSUFFLATIONThe rate and pressure of the gas flow into the abdominal cavity is controlled by the insufflator,which acts as an adjusta
17、ble interface between the pressurized gas bottle and the abdomen. The role ofthe insufflator is to control the flow of insufflant into the body in such a manner that the pressure staysvery close to predetermined parameters that may be chosen by the surgeon.Carbon dioxide (CO2) is the most commonly u
18、sed insufflant since it is inert, inexpensive, and verysoluble in blood, which decreases the risk of gas embolus. Due to its solubility into the bloodstream,CO2 may cause a mild respiratory acidosis, which should not be an issue during a general endotra-cheal anesthesia. Helium is also inert and may
19、 be safely used. Argon is not easily absorbed into thebloodstream, and consequently should not be used due to the risk of air embolus. Nitrous oxide cansupport combustion in combination with cautery or laser and should not be used as either an insufflantor an anesthetic.ACCESSDesigned for access int
20、o the peritoneal cavity, the Veress needle is a 14-guage needle with a springloaded blunt tip inner stylet which springs out to protect the abdominal contents after the needle isplaced through the fascia. After adequate insufflation pressure is achieved, a trocar with a scope inthe sheath may be use
21、d to visualize placement of the initial trocar. Subsequent trocars are then placedunder vision.Alternatively, a direct vision cutdown through the fascia may be performed with placement of theHasson trocar. The abdomen is then inflated after the initial port placement so the remaining trocarsmay be p
22、laced under vision.For retroperitoneal access, the working space may be created with a retroperitoneal balloon (USSurgical). The scope may be placed through the trocar into the balloon to allow visualization of theretroperitoneal structures through the balloon.TROCARSTrocars may be categorized as ei
23、ther bladed or non-bladed trocars (Fig. 2). Bladed trocars cutthrough the fascia, whereas non-bladed use different mechanisms to spread the fascia. Reusable bladedtrocars have a sharp trocar to pierce the fascia and disposable bladed trocars use a spring mechanismto retract the blade after it has cu
24、t completely through the fascia and entered the peritoneum (Fig. 2).A novel trocar uses a cutting blade with a protective tip to protect the abdominal contents (PassportTrocar, Patton Surgical). The blade has a protective tip that springs out over the sharp tip immediatelyupon entry of the tip of th
25、e blade into the abdomen, allowing the remainder of the blade to cut throughfascia with the tip covered to help prevent inadvertent visceral or vascular injury. Since all bladedtrocars cut the fascia, 5 and 10-mm sites must undergo fascial closure to prevent incisional herniaformation (5).Non-bladed
26、 trocars dilate the fascia rather than cut them. This creates a smaller fascial defect, whichreduces the risk of postoperative hernia formation (6). Some centers believe that closure of the fasciais unnecessary for 10-mm dilating trocars (7). Although the incidence is rare, one must note that trocar
27、site hernia has been described when the fascia is not closed, even with dilating trocars (5).Inallchildren, 5- and 10-mm port sites must be closed.Several types of dilating trocars exist. One design advances a cone-shaped plastic tip through thefascia in a twisting motion (Ethicon, Applied Medical).
28、 Another style, the Step trocar, places a sheaththrough the abdominal wall with the Veress needle (Tyco). Five or 10-mm trocars are placed throughthe sheath, which radially dilate the fascia in a stretching manner (Fig. 3) (8). This system allows thesurgeon to quickly replace a 5-mm trocar with a la
29、rger 10-mm size through the existing sheath.12 LowryFig. 2. 10-mm trocars. Upper trocar is bladed (Versaport plus V2, Autosuture); lower trocar is non-bladed (EndopathXcel, Ethicon). Upper inset shows non-bladed tip and bladed tip with sharp edge exposed. Lower inset illustrates howa 10-mm scope fit
30、s into trocar for visual placement.Fig. 3. Step trocar system (Tyco) with 5- and 10-mm trocar, and sheath. Insets show 5- and 10-mm trocars placedthrough the sheath.Laparoscopic Instrumentation 13Initial trocar placement must be done by the Hasson technique under direct vision, or using a visualdevi
31、ce after Veress needle insufflation (9). Two visual devices exist. The Optiview Excel (Ethicon) is adilating trocar that allows the scope to be placed inside the trocar (Fig. 2). This allows visualization ofthe trocar entry through the layers of the abdomen through the clear dilating tip. A similar
32、system, theVisiport (US Surgical) uses an optical system with a small trigger activated blade that snaps only 2mminto and then immediately back out of the tissue, to protect against inadvertent injury of abdominalcontents. By activating this blade repeatedly, one can watch the careful progress throu
33、gh the variouslayers of the abdomen until the peritoneum is entered. Care must be made not to apply too muchpressure, or injury of abdominal contents immediately below the fascia can occur.A novel port with multi-channel access that allows three instruments through one trocar that requiresonly a 34m
34、m incision (10). For nephrectomy, this results in one extraction incision through the singlelarger port site, as compared to current nephrectomy with the extraction incision and 23 additionalport sites.HAND-ASSIST DEVICESThe first-generation hand-assist ports have given way to the Omniport (Tyco), t
35、he Gelport (AppliedMedical), and the LapDisc (Ethicon). The Omniport is a one piece device that is inflated around thewrist to create an airtight seal. The LapDisc is comprised of two parts; the airtight seal is created byan adjustable iris type system that is tightened around the wrist. The most re
36、cent Gelport employs twopieces and has a soft gel cap that gently stretches around the wrist to create a seal. The Gelport allowsan instrument to be placed through the gel adjacent to the hand, allowing another instrument withoutrequiring another port placement. The Gelport also allows exchange of s
37、urgeons and assistants handswithout loss of pneumoperitoneum.The various ports have been directly compared and characterized by ease of device insertion, ease ofhand insertion, and exertion of forearm compression forces (11). The devices are all safe and effective,and surgeon preference will vary.Re
38、cently, small finger mounted dissecting devices (Ethicon) have been developed to potentiallyimprove the usefulness of the intra-abdominal hand. Currently, these are not yet available for clinicaluse and their utility remains to be proven.HEMOSTASISEnergy-Based DissectorsEarly energy-based dissection
39、 was performed with the hook monopolar cautery, which still haswidespread usage today. Monopolar energy may also be used with shears and graspers. The monopolarcurrent spreads out in all directions for several millimeters from the tips of monopolar devices, andgreat care must be taken to avoid caute
40、ry injury to nearby organs.Bipolar cautery allows the current to travel from one jaw of an instrument to the other jaw, whichfocuses the energy between the jaws, decreasing energy dispersion. Bipolar graspers may be used tocauterize a structure, which may then be divided. The Ligasure system (Valley
41、lab) uses bipolar energycombined with controlled pressure to seal vessels up to 7-mm in diameter. The Ligasure compressesthe tissue to be treated until it “clicks” into the proper pressure, after which the bipolar is delivered.This device has a feedback mechanism that automatically stops the energy
42、when the vessel is appro-priately sealed. After creating a wide seal, an integral blade is then manually activated to cut throughthe treated tissue (Fig. 4).The Harmonic Scalpel (Ethicon) and the Auto-Sonix (US Surgical) are ultrasonic devices whichuse ultrasound energy. Compared to the Auto-Sonix,
43、the Harmonic Scalpel has a superior dissecting14 LowryFig. 4. Ligasure (Valleylab). 5- and 10-mm devices. Inset illustrates close-up view of the instrument tips.tip, as well as the choice of either a straight or curved tip. Tissue is grasped between an active bladeand a passive blade with a protecti
44、ve Teflon backing. The active blade vibrates at 55,000 Hz, whichdenatures and coagulates proteins in the vessel walls, resulting in a protein coagulum that reliably sealssmall vessels. No electricity is used and the vessels are controlled at lower temperatures (50100C)than electrocautery (150200C).
45、Ultrasonic energy has very little thermal spread, less than 1mm (12),decreasing the chance for damage to adjacent organs. The Auto-Sonix and the Harmonic Scalpel canboth safely divide vessels 34-mm in diameter. The newer Harmonic ACE is approved for division ofvessels up to 5mm, albeit with higher t
46、emperatures. All instrument tips, especially the ACE, are hotimmediately after use, and contact with abdominal structures must be avoided to prevent inadvertentthermal damage (13).The argon beam coagulator employs a flow of argon gas by an electrode. When activated, the elec-trode produces a stream
47、of electrons to the tissue surface. Superficial bleeding is controlled withoutdeep dispersal of energy into the tissue. As the high flow of argon gas causes buildup of pressure,ports should be opened and insufflation pressures must be closely monitored to avoid air embolus orpneumothorax.Mechanical
48、Vascular ControlWhile energy-based dissectors control most potential bleeding encountered during surgery, theymay not be effective during active bleeding and cannot safely divide larger vessels. Energy may needto be avoided to prevent damage to nearby nerves through thermal spread. In these instance
49、s, bleedingmay be controlled and prevented by mechanically sealing vessels.Clips will control almost all vessels. Titanium clips are available in a disposable applier, whichrotate to simplify deployment. These are available in 5- and 10-mm sizes, with staples in line or atright angles to the applier (Fig. 5). Hem-O-Lok clips (Weck) are made of a non-absorbable polymerLaparoscopic Instrumentation 15Fig. 5. Disposable titanium clip appliers (Autosuture). 5-mm straight, 10-mm straight, and 10-mm right angle devices.Inset magnifies the instrument tips.and are less easily dislodged th
