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Endoscope-Assisted and Endoscopic Surgery
CHAPTER
14 Endoscope-Assisted and Endoscopic Surgery
In human medicine, endosurgery has been credited with numerous advantages over traditional open procedures, including reductions in pain, operating time, hospital stay, and convalescence period.1,2 While such advantages may be less easily quantified or published in veterinary medicine, over the past decade there have, nevertheless, been considerable advances in minimally invasive endosurgery of animals, including reptiles.3-6 Indeed, considering that most reptiles weigh less than a few kilograms, the development of minimally invasive endosurgery would seem a logical evolution in their surgical care, particularly given the hindrances of the chelonian shell.7 The transition from a technique that is purely diagnostic to one that is more complex and capable of surgical manipulation requires additional equipment and, perhaps even more taxing, a considerably more refined surgical skill set. It is no exaggeration to state that the technical difficulty associated with multiple-port endosurgery is a magnitude greater than that required for single-entry diagnostic endoscopy. This chapter is most certainly an extension of the previous chapter and should not be read in isolation. Only additional equipment and supplemental techniques are covered here, and a firm grounding in diagnostic endoscopy is assumed.
the insufflation line. The metal cannulae are more robust and heavier and therefore are used only for the animals weighing more than 10 kg (i.e., 6-mm cannulae for 5-mm instruments). The plastic/graphite models are extremely light and ideally suited to most small reptiles (i.e., 2.5-mm and 3.5-mm cannulae for 2-mm and 3-mm instruments, respectively). Most cannulae are used in conjunction with trocars. A trocar is a solid, often sharp and pointed, metal rod that is inserted into the cannula to assist with placement. Most are sharp to facilitate perforation of the body wall when axial and penetrative force is applied. The threaded cannula (e.g., EndoTip) is a recent improvement that has an external screw thread to enable gradual advancement by rotation (see Figure 13-2 C, D).9 These threaded cannulae are available in 3-mm, 3.9-mm, and 5-mm sizes and do not require a trocar or much axial penetrative force for insertion. A telescope positioned inside the cannula provides a magnified view during entry into the coelom. As the cannula is advanced, the fascia and then the muscle fibers 3 1 2
ENDOSURGICAL EQUIPMENT In addition to a telescope, one or more independent instruments must be introduced when the endoscopist operates inside a reptilian coelom.8 These instruments and the cannulae through which they pass are grouped into various size classes that are often color-coded. For example, 2-mm instruments are used in conjunction with 2.5-mm cannulae, 3-mm instruments with 3.5-mm cannulae, and 5-mm instruments with 6-mm cannulae (Figure 14-1). In addition, the 2.7-mm telescope housed within a 3.5-mm protection sheath will pass through a 3.9-mm cannula. A listing of available equipment is provided in Table 14-1.8
Cannulae and Trocars Cannulae are used to provide additional access ports (Figure 14-2). They are of surgical steel or graphite/plastic construction and have internal leaflet valves and optional insufflation stopcocks for CO2 delivery. These valves are designed to prevent loss of gas during insufflation. Insufflation stopcocks are optional, but at least one is required for the attachvment of
Stephen J. Divers
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FIGURE 14-1 Human pediatric 3-mm laparoscopy equip-
ment. A 3-mm instrument (1) attached to a standard ClickLine handle (2). The instrument, attached to a radiosurgery unit via a connector on the handle (3), has been inserted through a 3.5-mm graphite/plastic cannula (4). Inset, Instrument (1) and handle (2) can be quickly exchanged by pressing on the release button (arrow). The radiosurgical connection is also shown (3). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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TA B LE 1 4-1
Endoscopic Equipment and Instrumentation Required for Minimally Invasive Endosurgery EQUIPMENT DESCRIPTION TELESCOPES 1.9-mm, 30-degree oblique telescope, working length 18.5 cm, with integrated 3.3-mm operating sheath 2.7-mm, 30-degree oblique telescope, working length 18 cm, with 3.5-mm protection sheath 5-mm, 0-degree telescope, working length 29 cm 5 mm, 30-degree oblique telescope, working length 29 cm VISUALIZATION AND DOCUMENTATION Endovideo camera and monitor Xenon light source and light guide cable Digital capture device (e.g., AIDA-DVD) INSUFFLATION CO2 compressed gas with regulator and high-pressure tubing to CO2 insufflator, and silicone insufflation tubing from insufflator to patient HANDLES Two plastic handles without rackets One plastic handle with Mahnes-style racket One plastic handle with hemostat-style racket CANNULAE, TROCARS, AND INSTRUMENTS 3.9-mm graphite and plastic cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port 2.5-mm × 4-cm graphite and plastic threaded cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port (for 2-mm instruments, typically two required) 2-mm Reddick-Olsen dissecting forceps 2-mm Metzenbaum scissors 2-mm Babcock forceps 3.5-mm graphite and plastic threaded cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port (for 3-mm instruments, typically two required) 3-mm fenestrated grasping forceps 3-mm Reddick-Olsen dissecting and grasping forceps 3-mm short curved Kelly dissecting and grasping forceps 3-mm atraumatic dissecting and grasping forceps 3-mm Babcock forceps 3-mm Blakesley dissecting and biopsy forceps 3-mm scissors with serrated curved double action jaws 3-mm microhook scissors, single-action jaws 3-mm Mahnes bipolar coagulation forceps 3-mm irrigation and suction cannula 3-mm palpation probe with centimeter markings 3-mm distendable palpation probe 3-mm ultramicro needle holder 3-mm knot tier for extracorporeal suturing 6-mm × 5.5-mm Ternamian EndoTip cannula, with silicone leaflet valve and insufflation stopcock (for 5-mm instruments, typically two required) 5-mm biopsy forceps 5-mm Blakesley dissecting forceps 5-mm curved Kelly dissecting and grasping forceps 5-mm Babcock grasping forceps 5-mm curved Metzenbaum scissors 5-mm suction and irrigation cannula 5-mm needle holders 5-mm hook scissors 5-mm bipolar forceps
PRIMARY INDICATIONS Endosurgery in reptiles 0.1 to 5 kg Endosurgery in reptiles 0.5 to 10 kg Endosurgery in reptiles 10 to 100+ kg Endosurgery in reptiles 10 to 100+ kg Required for all endoscopy procedures
Essential for endosurgery in snakes and lizards, often useful for chelonians These ClickLine handles are interchangeable and can be used with most instruments from 2 mm to 5 mm
Accommodates 2.7-mm telescope and 3.5-mm protection sheath For endosurgery in animals 0.1 to 5 kg Instruments are all 20 cm in length
For endosurgery in animals 0.5 to 10 kg Instruments are all 20 cm in length
For endosurgery in animals 10 to 100 kg Instruments can be 36 cm or 43 cm in length
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Endoscopic Equipment and Instrumentation Required for Minimally Invasive Endosurgery—cont’d EQUIPMENT DESCRIPTION
PRIMARY INDICATIONS
HEMOSTASIS EQUIPMENT Ellman 3.8 or 4.0 MHz dual radiofrequency unit with foot pedal Karl Storz Autocon 80 unit with foot pedal Monopolar lead to connect to plastic instrument handles Bipolar lead to connect to 3-mm Mahnes bipolar coagulation forceps LigaSure ForceTriad energy platform with foot pedal 5-mm x 37-cm LigaSure laparoscopic instrument
Enables many endoscopic instruments to be used as monopolar devices and facilitates bipolar coagulation using bipolar forceps. A wide variety of 2-mm, 3-mm, and 5-mm instruments available Only available in 5-mm or 10-mm instrument sizes but is a useful instrument that combines sealing and cutting. The instruments are disposable human items, but most veterinarians clean and re-use
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sheath (1) inserted through a 3.9-mm × 10-cm graphite/plastic cannula with insufflation side port (2). B, A 3.9-mm × 10-cm graphite/plastic cannula disassembled to illustrate the graphite cannula (1), leaflet valve (2), screw cap (3), and instrument seal (4). C, A 3.9-mm × 10-cm graphite/plastic cannula with insufflation side port (1) and 3.5-mm × 10-cm threaded cannula with insufflation side port and trocar inserted (2). The 3.9-mm cannula can accommodate the 2.7-mm telescope housed in a 3.5-mm protection sheath, whereas the 3.5-mm cannula can accommodate 3-mm instruments. The threaded design resists dislodgement in small exotic species. D, Ternamian EndoTip cannulae; 6-mm × 15-cm with insufflation side port and multifunctional valve (1) and 6-mm × 10.5-cm cannula with silicone leaflet valve. These metal cannulae are far heavier and best restricted to animals weighing more than 10 kg. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-3 A, A terminal end of a 6-mm threaded cannula. Screwed entry of the
threaded cannula through an initial skin incision (B), subcutaneous tissue (C), and finally the coelomic membrane (D) before entering the coelomic cavity (E). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
spread radially and are transposed onto the cannula’s outer thread. The thin coelomic membrane is transilluminated so that viscera, vessels, and/or adhesions are visualized before entry into the coelom (Figure 14-3). The risks of iatrogenic visceral damage are therefore greatly reduced. In addition, the threads also provide greater security in that such cannulae are less likely to be dislodged.
Instruments and Handles At least one, generally two, and rarely three instruments are inserted through cannulae and into the endoscopic field of view. Instruments must be triangulated to bring the instrument tips together (convergence) and enable surgery within the reptilian coelom. A large assortment of 5-mm instruments are available; they were initially developed for humans but are equally applicable for animals more than 10 kg. However, it was not until the development of human pediatric laparoscopy that smaller 2-mm and 3-mm instruments became available and multipleentry endosurgery became feasible in smaller animals.10 Currently, 2-mm instruments are limited to Babcock forceps, dissecting forceps, and scissors. A greater selection of 3-mm instruments are available, including a variety of dissecting forceps, grasping forceps, scissors, biopsy forceps, and palpation and irrigation probes (Figure 14-4). All these instruments have a standard attachment that enables them to be used interchangeably with a selection of ClickLine handles (Figure 14-5). Handles are of plastic or metal construction and may have a radiosurgical connection that enables scissors or forceps to be used as monopolar devices. An optional hemostat,
Mahnes, or disengageable-style racket mechanism is available to maintain firm hold of tissue, even if the endoscopist releases the grip on the handle (see Figure 14-5, B, C, E).
Surgical Devices and Hemostasis Effective and safe performance of endoscopic surgery requires accurate hemostasis because the mere act of clamping a bleeding vessel or dabbing with gauze may be impossible. Radiosurgery and laser surgical devices have become available and can facilitate internal incision and debridément while hemorrhaging is controlled. Diode lasers (e.g., AccuVet Lumenis Inc., Norwood, Mass) are, by design, able to pass through flexible fiberoptic probes that can be inserted through instrument channels or cannulae (Figure 14-6).11,12 A variety of diode laser probes are available; however, 400 to 600 μm conical or flat tips at 2 to 10 watts are generally most useful (SurgiMedics Inc., The Woodlands, Tex). Until recently, CO2 lasers (AccuVet Lumenis Inc.) could not be used via endoscopic instrument channels because of the inflexible nature of the ceramic delivery probes. The development of a long semirigid probe (AccuVet Lumenis Inc.), however, has enabled the use of the CO2 laser via the 1.7-mm instrument channel of the 4.8-mm operating sheath. Nonetheless, although it is functional, it is rather cumbersome (Figure 14-7). Probably the most versatile device, especially when using 3-mm or smaller instrumentation systems, is a radiosurgery unit because a wide variety of tools are available for use with foot-pedal activated radiosurgery 3.8 and 4.0 MHz Surgitron, (Ellman International Inc., Oceanside, NY) (Figure 14-8) and electrocautery (Autocon 80, Karl Storz Veterinary
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FIGURE 14-4 A selection of 3-mm instruments. A, Forceps: fenestrated atraumatic grasping forceps (1), Reddick-Olsen dissecting forceps (2), small Babcock forceps (3), large Babcock forceps (4), short curved Kelly dissecting and grasping forceps (5), long curved Kelly dissecting and grasping forceps (6), and atraumatic dissecting and grasping forceps with single-action jaws (7). B, Scissors and biopsy instruments: microhook scissors with single action jaws (1), Blakesley dissecting and biopsy forceps (2), scissors with long sharp curved double action jaws (3), and scissors with serrated curved double action jaws (4). C, Probes: distendable palpation probe (1), palpation probe with centimeter markings (2), and irrigation and suction cannula (3). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Endoscopy, Goleta, Calif) units.13 The most useful includes various needle electrodes (Ellman International Inc), bipolar forceps, and a retractable polypectomy snare (Karl Storz Veterinary Endoscopy America Inc., Goleta, Calif). The degree of radiosurgical power required during endosurgery varies with operating conditions and the instrument being used, but because of the microsurgical nature of most endosurgical procedures, lower settings are generally required compared with open surgery. Considerable growth in endoscopic radiosurgery has led to the availability of a large number of monopolar and bipolar devices. One particularly favored device among human and veterinary endosurgeons is the LigaSure ForceTriad (Covidien, Boulder, Colo) (Figure 14-9). This system detects the thickness (by measuring the electrical impedance) of tissue to be coagulated and automatically defines the amount of energy required and the delivering time. An acoustic signal informs the surgeon when the vessel obliteration is complete and its division is possible. Unfortunately, endoscopic handpieces smaller than 5 mm are not yet available, limiting its usefulness to 5-mm systems and the largest of reptiles (Figure 14-10). Another useful item from human and domestic animal laparoscopy is the endoscopic vascular clip applicator (Figure 14-11). These devices contain a cartridge of clips that
can be rapidly employed without having to remove the instrument from the patient and reload. Again, the smallest available size is 5 mm, which restricts their use to the largest reptiles.
Endoscopy Tables In human and domestic animal endosurgery, tilting tables are used to modify patient positioning and create advantageous organ displacement during surgery. Most of the table-mounted configurations used in veterinary medicine are designed for mammals and are incompatible with most reptiles. In addition, joystick-controlled tilting surgery tables (Figure 14-12) are helpful but expensive and likely to be limited to teaching hospitals and other major referral institutions. Most practitioners can probably achieve similar positioning, albeit with less intraoperative versatility, by using towels, sandbags, vacuum pads, tape, and various other positioning aids (Figure 14-13).
Endosurgical Principles and Techniques As already indicated, endosurgery requires placement of the telescope and triangulation of additional instruments. Advanced endosurgical skills can only be built on a firm foundation in single-entry diagnostic endoscopy. Minor errors or inadequacies that can be tolerated in single-entry procedures
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FIGURE 14-5 Endoscopy instrument handles. A, Plastic handle (without racket) with radiosurgery connector (arrow). B, Plastic handle with hemostat-style racket (arrow). C, Plastic handle with Mahnes-style racket (arrow). D, Metal handle without racket or radiosurgery connection. E, Metal handle with disengageable racket but no radiosurgical connection. F, Metal Y-handle with spring action. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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the instrument channel of the 4.8-mm operating sheath and emanating from the terminal end of the sheath in front of the terminal telescope lens (inset). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-8 A, A 4.0 MHz dual frequency radiosurgery unit (4.0 MHz Surgitron, Ellman International, Inc.). B, Polypectomy snare handpiece with extended end shown (inset). C, Various radiosurgical endoscopic devices; retractable needle (1), dissecting hook (2), and bipolar forceps (3). Close-up of instrument ends also shown (inset) (Karl Storz Veterinary Endoscopy, Goleta, Calif). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-10 A LigaSure Atlas handpiece (Covidien, FIGURE 14-9 The LigaSure vessel sealing system and a
disposable 5-mm endoscopic sealing and cutting instrument. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Mansfield, Mass). This 10-mm instrument has a working length of 20 cm and is capable of sealing and transecting vessels up to 7 mm in size. The smallest diameter endoscopic instrument currently available is 5 mm, restricting this device to the largest of reptiles. (© University of Georgia Research Foundation, Inc.)
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FIGURE 14-11 This 5-mm endoscopic vascular clip has a working length of 28 cm and contains 12 titanium clips. (© University of Georgia Research Foundation, Inc.)
FIGURE 14-14 An endoscopy trainer fashioned from a modified plastic container. Holes at the front permit the introduction of the telescope, which is supported with sandbags. The top has been largely replaced by a sheet of rubber containing several holes for the introduction of instruments. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-12 Electronic tilting table with joy-stick control (arrow). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-13 A freshwater turtle positioned in right lateral
recumbency with the use of two towels taped together, in preparation for endosurgical orchidectomy. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
are likely to become magnified and cause serious problems during endosurgery. Well-executed and atraumatic placement of the telescope is essential and can only come from practice. Poor technique will result in tissue damage, increased tissue fluid including blood on the terminal lens, and decreased
visibility. The need to practice instrument triangulation and develop fine motor skills with limited tactile feedback in a three-dimensional environment exceeds the endoscopy caseload, at least initially. Therefore the reptile endoscopic surgeon must find additional means to practice and maintain skills. One method is to maintain equipment in a clean yet nonsterile state. This allows and encourages the veterinarian to practice on a cadaver, whereas using instruments that have undergone the entire sterilization process seems to present a barrier to practicing. In addition, inexpensive artificial trainers can be readily made from supplies found at local hobby and home improvement stores. A clear plastic container can serve as the basis for such a trainer. First, a large square hole is cut from the lid and replaced with rubber matting. Several 4-mm holes can be made in the rubber top and in the front of the container to provide a selection of instrument access ports (Figure 14-14). A variety of “endoscopy games” can be devised to be completed inside the box. These can include dissecting a drawn shape on tissue paper, picking up felt disks from one pin and transferring to a second pin, or even endoscopic suturing (Figure 14-15). Surgeon ergonomics also become increasingly important because fine motor control now becomes more complicated by the need to triangulate and establish a perception of depth with a two-dimensional monitor. The monitor should be directly in front of the surgeon who should be comfortably standing on a padded mat or sitting (Figure 14-16). Finally, the usual degree of tactile feedback experienced when handling tissues with standard instruments is greatly reduced when working with endoscopic instruments at distances of 20 cm or more from the tissues (Figure 14-17).
ENDOSCOPE-ASSISTED PROCEDURES An endoscope-assisted procedure is a hybrid that combines elements of endoscopy with traditional surgery. In its simplest form, an endoscope-assisted procedure uses endoscopy to identify and grasp an internal structure that is then exteriorized through a miniature coeliotomy incision for completion
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery
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FIGURE 14-15 Endoscopy training exercises. A-C, This basic exercise involves picking up a felt ring from one pin with the use of forceps, transferring the ring to a second pair of forceps, and then placing the ring on a second pin. This exercise helps with depth perception, instrument triangulation, and instrument-to-instrument transfer. It can be made more difficult by changing the orientation and direction of the pins. D-F, This more difficult exercise involves using forceps and scissors to dissect a shape from a piece of tissue paper. This game helps with depth perception, instrument triangulation, and instrument dexterity. It can be made more difficult by increasing the complexity of the shape and by swapping the scissors and forceps. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-16 Proper positioning and orientation of the surgeon(s) to the patient and monitor becomes increasingly critical with endosurgery. In this example, the two surgeons are perpendicular to the monitor while they perform endosurgery in a small chelonian. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-17 Tactile feedback and sensation is reduced dur-
ing endosurgery because tissues are manipulated at a greater distance than with traditional surgery. This photograph also shows the concept of triangulation with the two instruments (bipolar radiosurgery forceps [r] and grasping forceps [f]) on either side of the camera and telescope (t) but converging toward the common endoscopic field of view. The insufflation line (i) is also shown connected to a cannula. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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of the procedure outside the body cavity. The advantages of endoscope-assisted procedures are that they decrease the size of the coeliotomy incision and exposure of internal viscera to the environment. An assortment of endoscope-assisted coelomic procedures including enterotomy, enterectomy, cystotomy, salpingotomy, and salpingohysterectomy are now possible. These techniques rely on the ability to exteriorize the tissue of interest out through a small, targeted coeliotomy incision. If the tissue cannot be exteriorized, then the procedure cannot be completed externally, and a true endosurgical technique is required. Of particular practical relevance is endoscope-assisted, prefemoral oophorectomy (or ovariectomy) of mature female chelonians that negates the need for a transplastron coeliotomy.14 With the chelonian in dorsal recumbency, a unilateral, prefemoral coeliotomy is performed, typically 2 to 3 cm in size (large enough to exteriorize the largest follicle). The telescope is inserted through the coeliotomy site and used to identify the ovaries. The telescope guides a pair of atraumatic forceps, the interfollicular tissue is grasped, and the ovary is gently lifted out of the prefemoral incision. Once exteriorized, the ovarian vessels and mesovarian ligament is ligated and the ovary is dissected free. For those species with large prefemoral fossae, it is generally possible to remove the contralateral ovary through the same prefemoral incision. Those species with very small fossae may require a bilateral prefemoral approach. Similar endoscope-assisted procedures have also been accomplished for the removal of retained eggs, bladder calculi, and gastrointestinal foreign bodies and seem especially beneficial in chelonians. The general technique is similar, and endoscopy skills required are also very similar. First, diagnostic imaging is used to determine which side is favored for the approach. Then after a prefemoral coeliotomy, the telescope is used to identify the structure of interest and guide atraumatic tissue forceps. Any tissue that is due to be resected and removed can be grasped using Kelly or Babcock forceps (or a
similar type), but any tissue that is ultimately to be replaced should ideally be handled with atraumatic or fenestrated forceps. This is especially important when the bladder, gastrointestinal or reproductive tracts are handled.
ENDOSURGERY To date, endosurgery has been more commonly undertaken in chelonians, although endosurgical orchidectomy of iguanids has also been performed. Although established endosurgical dogma dictates that telescopes are often placed through the umbilicus or linea alba and instrument ports are placed far enough apart to facilitate triangulation, reptile anatomy often necessitates a modified approach. Endosurgical procedures usually commence with the placement of the telescope cannula, and there are two main techniques commonly used. Either the telescope cannula is surgically placed via a minicoeliotomy incision, after which the CO2 line is attached and the coelom insufflated, or a Veress needle (Figure 14-18), with CO2 line attached, is blindly inserted into the coelom to facilitate insufflation, after which the telescope cannula can be placed blindly with the use of a trocar to perforate the coelomic wall. Placing the telescope cannula surgically ensures intracoelomic placement and reduces the risk of iatrogenic trauma but requires a mattress suture around the cannula to close the incision to reduce gas leakage. Conversely, using a Veress needle to preinflate allows the telescope cannula to be placed through a smaller, trocar-induced hole without the need for suture but carries increased risks of iatrogenic trauma.
Chelonians Because of the constraints of the chelonian shell, it is seldom possible to place the telescope and ports where established protocols would suggest. There are two major approaches, depending on the size of the animal. For larger chelonians,
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CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery the telescope and instruments may all be inserted through one prefemoral fossa (Figure 14-19), whereas in smaller animals, the telescope and instruments may be placed through one or both fossae (Figure 14-20). There are advantages and disadvantages to both approaches. Placing all instrumentation through a single fossa enables the surgeon to control both instruments, even in large animals, but convergence is reduced because of the acute angles involved (often 30 degrees or less): instruments run more parallel, which makes their coordinated use more difficult. Nevertheless, compared with a bilateral fossa technique, a unilateral approach is less invasive in that only a unilateral surgical approach is required; in addition, it enables the animal to be positioned in lateral recumbency, which may aid organ visualization. A single surgeon can use both prefemoral fossae in smaller animals, but here the angle
FIGURE 14-19 Two 6-mm threaded cannulae placed through the same prefemoral fossa in an adult Aldabra Tortoise (Aldabrachelys [Geochelone] gigantea). The close placement of separate instruments makes triangulation more difficult because of their parallel orientation. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
of triangulation is often obtuse (90 degrees to 180 degrees), again making coordinated instrument manipulation more challenging. If the target structure is cranial to the bladder and the chelonian is less than 20 kg, it is often preferable for one instrument and telescope to be inserted through one prefemoral fossa while the second instrument is inserted through the contralateral fossa (see Figure 14-20). For such procedures, the animal is in dorsal recumbency and the advantage is that instruments can be more easily triangulated within the cranial to midcoelom. However, in larger chelonians, it can be difficult to impossible for a single surgeon to operate through both prefemoral fossae simultaneously, and in such cases, a second surgeon is required to operate through one fossa. The endosurgical approach to caudal structures (e.g., bladder, kidney, adrenal, or gonad) is more problematic because it is often difficult to access the same structure simultaneously from both fossae unless a significant angle-deflected endoscope is used (e.g., 90-degree). Therefore where a caudal structure is the focus of the procedure, insertion of telescope and instruments through a single prefemoral fossa may be preferable. In such cases, the chelonian is generally positioned in dorsal or lateral recumbency, which often provides greater accessibility because the intestines and bladder fall to the more dependent areas of the coelom. This approach is easier in those animals with a large prefemoral fossa; nevertheless, the close placement and parallel nature of instrumentation can make triangulation more difficult. In addition, it is often easier (especially in smaller animals) to make a single large prefemoral incision for the insertion of all instruments rather than place three cannulae adjacent to one another (Figure 14-21). Insufflation is seldom essential because of the noncollapsible nature of the chelonian shell; therefore endoscopic devices can still be used through an incision without the need for cannulae.
Oophorectomy of Immature Females. The only publication to date that describes a truly endosurgical coelioscopic procedure in a reptile involves oophorectomy in immature, hybrid
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FIGURE 14-20 A, Endoscopic view of the caudal coelom demonstrating the bladder (b) and right ovary (o) as seen through a left prefemoral approach in a Box Turtle (Terrapene carolina). In this example, an aspiration needle (arrow) has been placed through the same left fossa and is being used to perform cystocentesis. B and C, Endoscopic views of the cranial coelom and liver (l) of another Box Turtle with ascites, as seen through the left prefemoral fossa. Biopsy forceps (f) and irrigation/suction cannula (i) have been introduced through the right fossa, which provides greater instrument triangulation. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-21 Surgical view of a juvenile Galapagos Tortoise (Geochelone [Geochelone] nigra) undergoing endoscopic oophorectomy. Note that the telescope (t), handled by an assistant, as well as the grasping forceps (f) and radiosurgical scissors (s), operated by the primary surgeon, have all been introduced via a single prefemoral incision rather than through separate cannulae. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-22 Endoscopic left oophorectomy in a juvenile Galapagos Tortoise (Geochelone [Geochelone] nigra) with all instrumentation inserted through the left prefemoral fossa. A, Normal, immature left ovary (o) suspended from the caudodorsal body wall by a short mesovarium ligament (m). B, Grasping forceps (f) are introduced and used to grasp the mesovarium (m) but not the friable ovary (o). C, The mesovarium (m) is stretched by moving the forceps (f) cranially, while radiosurgical scissors (s) are used to incise through the suspensory ligament. D-F, Dissection through the mesovarium (m) continues using forceps (f) and scissors (s) until the ovary is dissected free and can be removed through the prefemoral incision. The incision is closed before the procedure is repeated via the right prefemoral fossa to remove the contralateral ovary. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery Oophorectomy of Mature Females. By virtue of the extensive mesovarian found in mature females, an endoscopeassisted procedure is practical in animals weighing a few hundred grams to 100 kg or more (Figure 14-23).13,14 With the chelonian in dorsal recumbency, a unilateral surgical approach to the coelom is made via one prefemoral fossa. The telescope is inserted into the coelom and used to locate the ipsilateral ovary. Then, the telescope is used to guide atraumatic forceps
(or even long hemostats in small chelonians) so that the interfollicular tissue is grasped and gently elevated to the skin incision. Once the first follicle is exteriorized, the telescope is no longer required because the ovary is carefully manipulated out of the coelom. Once the entire ovary is exteriorized, oophorectomy proceeds with the use of traditional techniques. The same procedure is repeated for the contralateral ovary, but it is usually not necessary nor recommended to remove the oviducts
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F FIGURE 14-23 Endoscope-assisted oophorectomy in an adult Red-eared Slider (Trachemys scripta elegans). A, After a prefemoral approach to the coelom, the ipsilateral ovary is located and retracted to the incision with the use of the telescope (t) and 3-mm atraumatic forceps (f). B, Endoscopic view of the caudal coelom demonstrating the ovary and three large ova (o), closely associated with the bladder (b) and intestine (i). C, Endoscopic view of 3-mm atraumatic forceps (f) being used to grasp the interfollicular tissue. D, Endoscopic view of the ovary being gently retracted toward the prefemoral incision. E, External view (taken using the telescope) demonstrating the first two follicles of the ovary exteriorized through the prefemoral incision. F, Continued manipulation to exteriorize the whole ovary precedes surgical oophorectomy with the use of radiosurgery. In most animals, the contralateral ovary can also be removed through the same prefemoral incision. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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unless diseased. In most species, both ovaries can be removed from the same incision; however, in some terrestrial tortoises with particularly restrictive prefemoral fossae, it may be necessary to perform a bilateral procedure. The prefemoral approach is closed routinely. This technique has several advantages over traditional plastronectomy, namely, a less invasive soft tissue approach instead of a bony approach, and faster healing.
Orchidectomy. Researchers have developed a similar approach for safe and effective orchidectomy, in red-eared sliders (Trachemys scripta elegans) and desert tortoises (Gopherus agassizii).15 The animal is again positioned in lateral recumbency and, after prefemoral coeliotomy, a surgical assistant identifies and maintains a clear view of the testis (Figure 14-24). The endosurgeon then uses Babcock or Kelly forceps to grasp and elevate the testis away from the kidney and epididymis to expose the mesorchium and associated vessels. Both monopolar radiosurgery and vascular clips have been used to ensure hemostasis before scissors are used to dissect the testis free (Figure 14-25). At least in the Red-eared Slider, it is possible to remove both testes via a unilateral prefemoral approach; however, in the desert tortoises a bilateral approach was necessary.
Lizards The most useful entry points for lizard diagnostic endoscopy also apply when instrument ports are considered. It is particularly important to remember that the standardized placement of cannulae through the linea alba cannot be applied to most lizards caudal to the umbilicus because of the presence of the midline abdominal vein; however, placement of a midline cannula, caudal to the umbilicus, is certainly practical and often preferred, particularly in iguanids (Figures 14-26 and 14-27).
Orchidectomy. With the iguana in right lateral recumbency, the telescope and protection sheath are inserted, just lateral to the ventral midline, close to the anastomosis of the left and right pelvic veins as they form the ventral abdominal vein (see Figure 14-26, C and Figure 14-28, B). The first cannula is placed cranial to the telescope, just caudal to the last rib, while the second cannula is placed caudal to the anastomosis of the pelvic veins in the ventral midline. Grasping forceps are inserted through one cannula and used to elevate the testis, while scissors (attached to monopolar radiosurgery device) are inserted through the other cannula and used to coagulate and cut through the mesorchium and associated vessels (Figure 14-29). In larger iguanas, bipolar forceps are used to coagulate blood vessels before sharp dissection. The testis is extracted through the forceps cannula hole, which can be enlarged, if necessary. The cannula holes are closed with a single suture or tissue adhesive. The iguana is rotated into left lateral recumbency, and using the same entry sites, the endoscopist repeats the procedure for the second testis.
ENDOSCOPY TRAINING The ability to perform endosurgery is not innate, and training is certainly required. Fortunately, various continuing education courses offer training in the United States and, less commonly, elsewhere. The Association of Reptilian and Amphibian Veterinarians (www.arav.org) regularly offers a 4-hour introduction to reptile endoscopy at its annual conference. In addition, the University of Georgia offers a 2-day course in reptile/avian, and another in small mammal endoscopy every year, with more advanced endosurgery courses offered intermittently (www.vet.uga.edu/CE/).
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B FIGURE 14-24 A, Endoscopic orchidectomy in a Red-eared Slider (Trachemys scripta
elegans). B, Close-up of the surgical site. Note that the assistant controls the camera and telescope (t) while the primary surgeon uses 3-mm grasping forceps (f) and a vascular clip applicator (v) to perform the orchidectomy. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery
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FIGURE 14-25 Endoscopic orchidectomy in the Red-eared Slider (Trachemys scripta elegans) via a unilateral prefemoral incision. A, View of the left testis (t) and epididymis (e) closely associated with the kidney (k) and renal vein (v). The descending colon (c) and caudal lung (l) are also visible. B, 3-mm Kelly forceps (f) are introduced and used to grasp the testis (t). C, The forceps are angled to retract the testis (t) cranially away from the epididymis (e) to expose the mesorchium (m) and associated vascular supply. D-F, Orchidectomy using vascular clips. A vascular clip applicator (v) is introduced and a single clip (arrow) is placed across the mesorchium (m), between the testis (t) and the epididymis (e), before the testis is dissected free using 3-mm scissors (s). G-I, Orchidectomy using radiosurgery. While the testis (t) is retracted away from the epididymis (e), monopolar scissors (s) are used to coagulate the mesorchial vessels (m), before the testis is dissected free and removed with forceps (f). After orchidectomy, the adrenal gland (a) can be seen. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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possible cannula insertion points (x) for performing multiple-entry endosurgery in lizards. The positions of the vertebral spine (v), last rib (r), ventral abdominal vein (av), and pelvic veins (pv) have been shown to indicate anatomic landmarks that should be appreciated. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-27 A, A primary surgeon and assistant performing endosurgery in a Green
Iguana (Iguana iguana). B, Close-up of the surgical site demonstrating the placement of the sheathed telescope with insufflation line attached (t) and a 3.5-mm cannula (c). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Surgeon Radiosurgery or laser
Instruments
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Light source insufflator camera digital recorder
FIGURE 14-28 A, General schematic and orientation
for performing endosurgical orchidectomy in an iguanid. As an alternative, positioning aids can be used to support the telescope and camera, allowing the monitor to be moved in front of the surgeon. B, Diagram illustrating the use of an assistant to support the telescope and camera (t), while the primary (right-handed) surgeon uses forceps (f) in the left hand and monopolar scissors (s) in the right hand to perform endosurgery within the dorsolateral coelom. (Art by Kip Carter [UGA], © University of Georgia Research Foundation, Inc.)
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FIGURE 14-29 Endoscopic orchidecto-
my in a Green Iguana (Iguana iguana). A, View of the dorsal coelom showing the right testis (t) and closely associated renal vein (v). B, Forceps (f), introduced through a caudal cannula, are used to grasp and elevate the testis (t) away from the body wall. C, With the testis (t) elevated away from the renal vein (v), monopolar scissors (s) are used to coagulate and cut across the mesorchium. D, The freed testis (t) is then retracted to the cannula (c), which is slid up the shaft of the forceps before the testis is removed through the cannula hole. If the testis is large, hemostats can be used to temporarily stretch the cannula hole to facilitate removal. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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ACKNOWLEDGMENTS The author would like to thank Karl Storz Veterinary Endoscopy and, in particular, Dr. Chris Chamness, Mike Bateman, and Dan McMahon for supporting endoscopy research, development, and training at the University of Georgia. In addition, the author is indebted to Drs. Scott Stahl, Charles Innis, Sam Rivera, Chris Hanley, Jason Norman, Emi Knafo, Randon Feinsod, Justin Oguni, Joe Flannagan, Heather Barron, Johanna Mejia-Fava, Jörg Mayer, Rodney Schnellbacher, and Laila Proenca for their collegiality and assistance in various endoscopic ventures at the University of Georgia.
REFERENCES 1. Lagares-Garcia JA, Bansidhar B, Moore RA. Benefits of laparoscopy in middle-aged patients. Surg Endosc 2003;17:68-72. 2. Yu SY, Chiu JH, Loong CC, et al. Diagnostic laparoscopy: indication and benefit. Zhonghua Yi Xue Za Zhi (Taipei) 1997;59:158-163. 3. Lhermette P, Sobel D. BSAVA manual of canine and feline endoscopy and endosurgery. 1st ed. Cheltenham, England: British Small Animal Veterinary Association, 2008. 4. McCarthy TC. Veterinary endoscopy for the small animal practitioner. St Louis: Elsevier, 2005. 5. Tams TR, Rawlings CA. Small animal endoscopy. 3rd ed. St Louis: Elsevier, 2011. 6. Divers SJ. Endoscopy and endosurgery. Vet Clin North Am Exot Anim Pract 2010;13:171-331.
7. Divers SJ. Reptile diagnostic endoscopy and endosurgery. Vet Clin North Am Exot Anim Pract 2010;13:217-242. 8. Divers SJ. Endoscopy equipment and instrumentation for use in exotic animal veterinary medicine. Vet Clin North Am Exot Anim Pract 2010;13:171-185. 9. Ternamian AM, Deitel M. Endoscopic threaded imaging port (EndoTIP) for laparoscopy: experience with different body weights. Obes Surg 1999;9:44-47. 10. Hernandez-Divers SJ. Minimally-invasive endoscopic surgery of birds. J Avian Med Surg 2005;19:107-120 11. Hernandez-Divers SJ. Endosurgical debridement and diode laser ablation of lung and air sac granulomas in psittacine birds. J Avian Med Surg 2002;16:138-145. 12. Hernandez-Divers SJ. Diode laser surgery: principles and application in exotic animals. Semin Avian Exot Pet Med 2002;11:208-220. 13. Knafo SE, Divers SJ, Rivera S, et al. Sterilization of hybrid Galapagos tortoises (Geochelone nigra) for island restoration: Part 1 female endoscopic oophorectomy under ketamine-medetomidine anaesthesia. Vet Rec 2010;168:47-51. 14. Innis C, Hernandez-Divers SJ, Martinez-Jimenez D. Coelioscopicassisted prefemoral oophorectomy in chelonians. J Am Vet Med Assoc 2007;230:1049-1052. 15. Innis CJ, Feinsod R, Hanlon J, et al. Coelioscopic orchiectomy can be effectively and safely accomplished in chelonians. Vet Rec 2013; 18;172:526. Epub 2013 Apr 4.
14 Endoscope-Assisted and Endoscopic Surgery
In human medicine, endosurgery has been credited with numerous advantages over traditional open procedures, including reductions in pain, operating time, hospital stay, and convalescence period.1,2 While such advantages may be less easily quantified or published in veterinary medicine, over the past decade there have, nevertheless, been considerable advances in minimally invasive endosurgery of animals, including reptiles.3-6 Indeed, considering that most reptiles weigh less than a few kilograms, the development of minimally invasive endosurgery would seem a logical evolution in their surgical care, particularly given the hindrances of the chelonian shell.7 The transition from a technique that is purely diagnostic to one that is more complex and capable of surgical manipulation requires additional equipment and, perhaps even more taxing, a considerably more refined surgical skill set. It is no exaggeration to state that the technical difficulty associated with multiple-port endosurgery is a magnitude greater than that required for single-entry diagnostic endoscopy. This chapter is most certainly an extension of the previous chapter and should not be read in isolation. Only additional equipment and supplemental techniques are covered here, and a firm grounding in diagnostic endoscopy is assumed.
the insufflation line. The metal cannulae are more robust and heavier and therefore are used only for the animals weighing more than 10 kg (i.e., 6-mm cannulae for 5-mm instruments). The plastic/graphite models are extremely light and ideally suited to most small reptiles (i.e., 2.5-mm and 3.5-mm cannulae for 2-mm and 3-mm instruments, respectively). Most cannulae are used in conjunction with trocars. A trocar is a solid, often sharp and pointed, metal rod that is inserted into the cannula to assist with placement. Most are sharp to facilitate perforation of the body wall when axial and penetrative force is applied. The threaded cannula (e.g., EndoTip) is a recent improvement that has an external screw thread to enable gradual advancement by rotation (see Figure 13-2 C, D).9 These threaded cannulae are available in 3-mm, 3.9-mm, and 5-mm sizes and do not require a trocar or much axial penetrative force for insertion. A telescope positioned inside the cannula provides a magnified view during entry into the coelom. As the cannula is advanced, the fascia and then the muscle fibers 3 1 2
ENDOSURGICAL EQUIPMENT In addition to a telescope, one or more independent instruments must be introduced when the endoscopist operates inside a reptilian coelom.8 These instruments and the cannulae through which they pass are grouped into various size classes that are often color-coded. For example, 2-mm instruments are used in conjunction with 2.5-mm cannulae, 3-mm instruments with 3.5-mm cannulae, and 5-mm instruments with 6-mm cannulae (Figure 14-1). In addition, the 2.7-mm telescope housed within a 3.5-mm protection sheath will pass through a 3.9-mm cannula. A listing of available equipment is provided in Table 14-1.8
Cannulae and Trocars Cannulae are used to provide additional access ports (Figure 14-2). They are of surgical steel or graphite/plastic construction and have internal leaflet valves and optional insufflation stopcocks for CO2 delivery. These valves are designed to prevent loss of gas during insufflation. Insufflation stopcocks are optional, but at least one is required for the attachvment of
Stephen J. Divers
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FIGURE 14-1 Human pediatric 3-mm laparoscopy equip-
ment. A 3-mm instrument (1) attached to a standard ClickLine handle (2). The instrument, attached to a radiosurgery unit via a connector on the handle (3), has been inserted through a 3.5-mm graphite/plastic cannula (4). Inset, Instrument (1) and handle (2) can be quickly exchanged by pressing on the release button (arrow). The radiosurgical connection is also shown (3). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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TA B LE 1 4-1
Endoscopic Equipment and Instrumentation Required for Minimally Invasive Endosurgery EQUIPMENT DESCRIPTION TELESCOPES 1.9-mm, 30-degree oblique telescope, working length 18.5 cm, with integrated 3.3-mm operating sheath 2.7-mm, 30-degree oblique telescope, working length 18 cm, with 3.5-mm protection sheath 5-mm, 0-degree telescope, working length 29 cm 5 mm, 30-degree oblique telescope, working length 29 cm VISUALIZATION AND DOCUMENTATION Endovideo camera and monitor Xenon light source and light guide cable Digital capture device (e.g., AIDA-DVD) INSUFFLATION CO2 compressed gas with regulator and high-pressure tubing to CO2 insufflator, and silicone insufflation tubing from insufflator to patient HANDLES Two plastic handles without rackets One plastic handle with Mahnes-style racket One plastic handle with hemostat-style racket CANNULAE, TROCARS, AND INSTRUMENTS 3.9-mm graphite and plastic cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port 2.5-mm × 4-cm graphite and plastic threaded cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port (for 2-mm instruments, typically two required) 2-mm Reddick-Olsen dissecting forceps 2-mm Metzenbaum scissors 2-mm Babcock forceps 3.5-mm graphite and plastic threaded cannula and trocar, with silicone leaflet valve, and luer-lock insufflation port (for 3-mm instruments, typically two required) 3-mm fenestrated grasping forceps 3-mm Reddick-Olsen dissecting and grasping forceps 3-mm short curved Kelly dissecting and grasping forceps 3-mm atraumatic dissecting and grasping forceps 3-mm Babcock forceps 3-mm Blakesley dissecting and biopsy forceps 3-mm scissors with serrated curved double action jaws 3-mm microhook scissors, single-action jaws 3-mm Mahnes bipolar coagulation forceps 3-mm irrigation and suction cannula 3-mm palpation probe with centimeter markings 3-mm distendable palpation probe 3-mm ultramicro needle holder 3-mm knot tier for extracorporeal suturing 6-mm × 5.5-mm Ternamian EndoTip cannula, with silicone leaflet valve and insufflation stopcock (for 5-mm instruments, typically two required) 5-mm biopsy forceps 5-mm Blakesley dissecting forceps 5-mm curved Kelly dissecting and grasping forceps 5-mm Babcock grasping forceps 5-mm curved Metzenbaum scissors 5-mm suction and irrigation cannula 5-mm needle holders 5-mm hook scissors 5-mm bipolar forceps
PRIMARY INDICATIONS Endosurgery in reptiles 0.1 to 5 kg Endosurgery in reptiles 0.5 to 10 kg Endosurgery in reptiles 10 to 100+ kg Endosurgery in reptiles 10 to 100+ kg Required for all endoscopy procedures
Essential for endosurgery in snakes and lizards, often useful for chelonians These ClickLine handles are interchangeable and can be used with most instruments from 2 mm to 5 mm
Accommodates 2.7-mm telescope and 3.5-mm protection sheath For endosurgery in animals 0.1 to 5 kg Instruments are all 20 cm in length
For endosurgery in animals 0.5 to 10 kg Instruments are all 20 cm in length
For endosurgery in animals 10 to 100 kg Instruments can be 36 cm or 43 cm in length
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery
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Endoscopic Equipment and Instrumentation Required for Minimally Invasive Endosurgery—cont’d EQUIPMENT DESCRIPTION
PRIMARY INDICATIONS
HEMOSTASIS EQUIPMENT Ellman 3.8 or 4.0 MHz dual radiofrequency unit with foot pedal Karl Storz Autocon 80 unit with foot pedal Monopolar lead to connect to plastic instrument handles Bipolar lead to connect to 3-mm Mahnes bipolar coagulation forceps LigaSure ForceTriad energy platform with foot pedal 5-mm x 37-cm LigaSure laparoscopic instrument
Enables many endoscopic instruments to be used as monopolar devices and facilitates bipolar coagulation using bipolar forceps. A wide variety of 2-mm, 3-mm, and 5-mm instruments available Only available in 5-mm or 10-mm instrument sizes but is a useful instrument that combines sealing and cutting. The instruments are disposable human items, but most veterinarians clean and re-use
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D FIGURE 14-2 Cannulae and trocars. A, A 2.7-mm telescope within a 3.5-mm protection
sheath (1) inserted through a 3.9-mm × 10-cm graphite/plastic cannula with insufflation side port (2). B, A 3.9-mm × 10-cm graphite/plastic cannula disassembled to illustrate the graphite cannula (1), leaflet valve (2), screw cap (3), and instrument seal (4). C, A 3.9-mm × 10-cm graphite/plastic cannula with insufflation side port (1) and 3.5-mm × 10-cm threaded cannula with insufflation side port and trocar inserted (2). The 3.9-mm cannula can accommodate the 2.7-mm telescope housed in a 3.5-mm protection sheath, whereas the 3.5-mm cannula can accommodate 3-mm instruments. The threaded design resists dislodgement in small exotic species. D, Ternamian EndoTip cannulae; 6-mm × 15-cm with insufflation side port and multifunctional valve (1) and 6-mm × 10.5-cm cannula with silicone leaflet valve. These metal cannulae are far heavier and best restricted to animals weighing more than 10 kg. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-3 A, A terminal end of a 6-mm threaded cannula. Screwed entry of the
threaded cannula through an initial skin incision (B), subcutaneous tissue (C), and finally the coelomic membrane (D) before entering the coelomic cavity (E). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
spread radially and are transposed onto the cannula’s outer thread. The thin coelomic membrane is transilluminated so that viscera, vessels, and/or adhesions are visualized before entry into the coelom (Figure 14-3). The risks of iatrogenic visceral damage are therefore greatly reduced. In addition, the threads also provide greater security in that such cannulae are less likely to be dislodged.
Instruments and Handles At least one, generally two, and rarely three instruments are inserted through cannulae and into the endoscopic field of view. Instruments must be triangulated to bring the instrument tips together (convergence) and enable surgery within the reptilian coelom. A large assortment of 5-mm instruments are available; they were initially developed for humans but are equally applicable for animals more than 10 kg. However, it was not until the development of human pediatric laparoscopy that smaller 2-mm and 3-mm instruments became available and multipleentry endosurgery became feasible in smaller animals.10 Currently, 2-mm instruments are limited to Babcock forceps, dissecting forceps, and scissors. A greater selection of 3-mm instruments are available, including a variety of dissecting forceps, grasping forceps, scissors, biopsy forceps, and palpation and irrigation probes (Figure 14-4). All these instruments have a standard attachment that enables them to be used interchangeably with a selection of ClickLine handles (Figure 14-5). Handles are of plastic or metal construction and may have a radiosurgical connection that enables scissors or forceps to be used as monopolar devices. An optional hemostat,
Mahnes, or disengageable-style racket mechanism is available to maintain firm hold of tissue, even if the endoscopist releases the grip on the handle (see Figure 14-5, B, C, E).
Surgical Devices and Hemostasis Effective and safe performance of endoscopic surgery requires accurate hemostasis because the mere act of clamping a bleeding vessel or dabbing with gauze may be impossible. Radiosurgery and laser surgical devices have become available and can facilitate internal incision and debridément while hemorrhaging is controlled. Diode lasers (e.g., AccuVet Lumenis Inc., Norwood, Mass) are, by design, able to pass through flexible fiberoptic probes that can be inserted through instrument channels or cannulae (Figure 14-6).11,12 A variety of diode laser probes are available; however, 400 to 600 μm conical or flat tips at 2 to 10 watts are generally most useful (SurgiMedics Inc., The Woodlands, Tex). Until recently, CO2 lasers (AccuVet Lumenis Inc.) could not be used via endoscopic instrument channels because of the inflexible nature of the ceramic delivery probes. The development of a long semirigid probe (AccuVet Lumenis Inc.), however, has enabled the use of the CO2 laser via the 1.7-mm instrument channel of the 4.8-mm operating sheath. Nonetheless, although it is functional, it is rather cumbersome (Figure 14-7). Probably the most versatile device, especially when using 3-mm or smaller instrumentation systems, is a radiosurgery unit because a wide variety of tools are available for use with foot-pedal activated radiosurgery 3.8 and 4.0 MHz Surgitron, (Ellman International Inc., Oceanside, NY) (Figure 14-8) and electrocautery (Autocon 80, Karl Storz Veterinary
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FIGURE 14-4 A selection of 3-mm instruments. A, Forceps: fenestrated atraumatic grasping forceps (1), Reddick-Olsen dissecting forceps (2), small Babcock forceps (3), large Babcock forceps (4), short curved Kelly dissecting and grasping forceps (5), long curved Kelly dissecting and grasping forceps (6), and atraumatic dissecting and grasping forceps with single-action jaws (7). B, Scissors and biopsy instruments: microhook scissors with single action jaws (1), Blakesley dissecting and biopsy forceps (2), scissors with long sharp curved double action jaws (3), and scissors with serrated curved double action jaws (4). C, Probes: distendable palpation probe (1), palpation probe with centimeter markings (2), and irrigation and suction cannula (3). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Endoscopy, Goleta, Calif) units.13 The most useful includes various needle electrodes (Ellman International Inc), bipolar forceps, and a retractable polypectomy snare (Karl Storz Veterinary Endoscopy America Inc., Goleta, Calif). The degree of radiosurgical power required during endosurgery varies with operating conditions and the instrument being used, but because of the microsurgical nature of most endosurgical procedures, lower settings are generally required compared with open surgery. Considerable growth in endoscopic radiosurgery has led to the availability of a large number of monopolar and bipolar devices. One particularly favored device among human and veterinary endosurgeons is the LigaSure ForceTriad (Covidien, Boulder, Colo) (Figure 14-9). This system detects the thickness (by measuring the electrical impedance) of tissue to be coagulated and automatically defines the amount of energy required and the delivering time. An acoustic signal informs the surgeon when the vessel obliteration is complete and its division is possible. Unfortunately, endoscopic handpieces smaller than 5 mm are not yet available, limiting its usefulness to 5-mm systems and the largest of reptiles (Figure 14-10). Another useful item from human and domestic animal laparoscopy is the endoscopic vascular clip applicator (Figure 14-11). These devices contain a cartridge of clips that
can be rapidly employed without having to remove the instrument from the patient and reload. Again, the smallest available size is 5 mm, which restricts their use to the largest reptiles.
Endoscopy Tables In human and domestic animal endosurgery, tilting tables are used to modify patient positioning and create advantageous organ displacement during surgery. Most of the table-mounted configurations used in veterinary medicine are designed for mammals and are incompatible with most reptiles. In addition, joystick-controlled tilting surgery tables (Figure 14-12) are helpful but expensive and likely to be limited to teaching hospitals and other major referral institutions. Most practitioners can probably achieve similar positioning, albeit with less intraoperative versatility, by using towels, sandbags, vacuum pads, tape, and various other positioning aids (Figure 14-13).
Endosurgical Principles and Techniques As already indicated, endosurgery requires placement of the telescope and triangulation of additional instruments. Advanced endosurgical skills can only be built on a firm foundation in single-entry diagnostic endoscopy. Minor errors or inadequacies that can be tolerated in single-entry procedures
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FIGURE 14-5 Endoscopy instrument handles. A, Plastic handle (without racket) with radiosurgery connector (arrow). B, Plastic handle with hemostat-style racket (arrow). C, Plastic handle with Mahnes-style racket (arrow). D, Metal handle without racket or radiosurgery connection. E, Metal handle with disengageable racket but no radiosurgical connection. F, Metal Y-handle with spring action. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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B FIGURE 14-6 A, A 980-μm diode laser unit. B, A 600-μm diode laser fiber inserted down
the instrument channel of the 4.8-mm operating sheath and emanating from the terminal end of the sheath in front of the terminal telescope lens (inset). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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B FIGURE 14-7 A, Elongated ceramic CO2 laser tip inserted down the instrument channel of the 4.8-mm operating sheath. B, The same ceramic tip alongside the sheath. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-8 A, A 4.0 MHz dual frequency radiosurgery unit (4.0 MHz Surgitron, Ellman International, Inc.). B, Polypectomy snare handpiece with extended end shown (inset). C, Various radiosurgical endoscopic devices; retractable needle (1), dissecting hook (2), and bipolar forceps (3). Close-up of instrument ends also shown (inset) (Karl Storz Veterinary Endoscopy, Goleta, Calif). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-10 A LigaSure Atlas handpiece (Covidien, FIGURE 14-9 The LigaSure vessel sealing system and a
disposable 5-mm endoscopic sealing and cutting instrument. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Mansfield, Mass). This 10-mm instrument has a working length of 20 cm and is capable of sealing and transecting vessels up to 7 mm in size. The smallest diameter endoscopic instrument currently available is 5 mm, restricting this device to the largest of reptiles. (© University of Georgia Research Foundation, Inc.)
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FIGURE 14-11 This 5-mm endoscopic vascular clip has a working length of 28 cm and contains 12 titanium clips. (© University of Georgia Research Foundation, Inc.)
FIGURE 14-14 An endoscopy trainer fashioned from a modified plastic container. Holes at the front permit the introduction of the telescope, which is supported with sandbags. The top has been largely replaced by a sheet of rubber containing several holes for the introduction of instruments. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-12 Electronic tilting table with joy-stick control (arrow). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-13 A freshwater turtle positioned in right lateral
recumbency with the use of two towels taped together, in preparation for endosurgical orchidectomy. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
are likely to become magnified and cause serious problems during endosurgery. Well-executed and atraumatic placement of the telescope is essential and can only come from practice. Poor technique will result in tissue damage, increased tissue fluid including blood on the terminal lens, and decreased
visibility. The need to practice instrument triangulation and develop fine motor skills with limited tactile feedback in a three-dimensional environment exceeds the endoscopy caseload, at least initially. Therefore the reptile endoscopic surgeon must find additional means to practice and maintain skills. One method is to maintain equipment in a clean yet nonsterile state. This allows and encourages the veterinarian to practice on a cadaver, whereas using instruments that have undergone the entire sterilization process seems to present a barrier to practicing. In addition, inexpensive artificial trainers can be readily made from supplies found at local hobby and home improvement stores. A clear plastic container can serve as the basis for such a trainer. First, a large square hole is cut from the lid and replaced with rubber matting. Several 4-mm holes can be made in the rubber top and in the front of the container to provide a selection of instrument access ports (Figure 14-14). A variety of “endoscopy games” can be devised to be completed inside the box. These can include dissecting a drawn shape on tissue paper, picking up felt disks from one pin and transferring to a second pin, or even endoscopic suturing (Figure 14-15). Surgeon ergonomics also become increasingly important because fine motor control now becomes more complicated by the need to triangulate and establish a perception of depth with a two-dimensional monitor. The monitor should be directly in front of the surgeon who should be comfortably standing on a padded mat or sitting (Figure 14-16). Finally, the usual degree of tactile feedback experienced when handling tissues with standard instruments is greatly reduced when working with endoscopic instruments at distances of 20 cm or more from the tissues (Figure 14-17).
ENDOSCOPE-ASSISTED PROCEDURES An endoscope-assisted procedure is a hybrid that combines elements of endoscopy with traditional surgery. In its simplest form, an endoscope-assisted procedure uses endoscopy to identify and grasp an internal structure that is then exteriorized through a miniature coeliotomy incision for completion
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery
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FIGURE 14-15 Endoscopy training exercises. A-C, This basic exercise involves picking up a felt ring from one pin with the use of forceps, transferring the ring to a second pair of forceps, and then placing the ring on a second pin. This exercise helps with depth perception, instrument triangulation, and instrument-to-instrument transfer. It can be made more difficult by changing the orientation and direction of the pins. D-F, This more difficult exercise involves using forceps and scissors to dissect a shape from a piece of tissue paper. This game helps with depth perception, instrument triangulation, and instrument dexterity. It can be made more difficult by increasing the complexity of the shape and by swapping the scissors and forceps. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-16 Proper positioning and orientation of the surgeon(s) to the patient and monitor becomes increasingly critical with endosurgery. In this example, the two surgeons are perpendicular to the monitor while they perform endosurgery in a small chelonian. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
FIGURE 14-17 Tactile feedback and sensation is reduced dur-
ing endosurgery because tissues are manipulated at a greater distance than with traditional surgery. This photograph also shows the concept of triangulation with the two instruments (bipolar radiosurgery forceps [r] and grasping forceps [f]) on either side of the camera and telescope (t) but converging toward the common endoscopic field of view. The insufflation line (i) is also shown connected to a cannula. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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of the procedure outside the body cavity. The advantages of endoscope-assisted procedures are that they decrease the size of the coeliotomy incision and exposure of internal viscera to the environment. An assortment of endoscope-assisted coelomic procedures including enterotomy, enterectomy, cystotomy, salpingotomy, and salpingohysterectomy are now possible. These techniques rely on the ability to exteriorize the tissue of interest out through a small, targeted coeliotomy incision. If the tissue cannot be exteriorized, then the procedure cannot be completed externally, and a true endosurgical technique is required. Of particular practical relevance is endoscope-assisted, prefemoral oophorectomy (or ovariectomy) of mature female chelonians that negates the need for a transplastron coeliotomy.14 With the chelonian in dorsal recumbency, a unilateral, prefemoral coeliotomy is performed, typically 2 to 3 cm in size (large enough to exteriorize the largest follicle). The telescope is inserted through the coeliotomy site and used to identify the ovaries. The telescope guides a pair of atraumatic forceps, the interfollicular tissue is grasped, and the ovary is gently lifted out of the prefemoral incision. Once exteriorized, the ovarian vessels and mesovarian ligament is ligated and the ovary is dissected free. For those species with large prefemoral fossae, it is generally possible to remove the contralateral ovary through the same prefemoral incision. Those species with very small fossae may require a bilateral prefemoral approach. Similar endoscope-assisted procedures have also been accomplished for the removal of retained eggs, bladder calculi, and gastrointestinal foreign bodies and seem especially beneficial in chelonians. The general technique is similar, and endoscopy skills required are also very similar. First, diagnostic imaging is used to determine which side is favored for the approach. Then after a prefemoral coeliotomy, the telescope is used to identify the structure of interest and guide atraumatic tissue forceps. Any tissue that is due to be resected and removed can be grasped using Kelly or Babcock forceps (or a
similar type), but any tissue that is ultimately to be replaced should ideally be handled with atraumatic or fenestrated forceps. This is especially important when the bladder, gastrointestinal or reproductive tracts are handled.
ENDOSURGERY To date, endosurgery has been more commonly undertaken in chelonians, although endosurgical orchidectomy of iguanids has also been performed. Although established endosurgical dogma dictates that telescopes are often placed through the umbilicus or linea alba and instrument ports are placed far enough apart to facilitate triangulation, reptile anatomy often necessitates a modified approach. Endosurgical procedures usually commence with the placement of the telescope cannula, and there are two main techniques commonly used. Either the telescope cannula is surgically placed via a minicoeliotomy incision, after which the CO2 line is attached and the coelom insufflated, or a Veress needle (Figure 14-18), with CO2 line attached, is blindly inserted into the coelom to facilitate insufflation, after which the telescope cannula can be placed blindly with the use of a trocar to perforate the coelomic wall. Placing the telescope cannula surgically ensures intracoelomic placement and reduces the risk of iatrogenic trauma but requires a mattress suture around the cannula to close the incision to reduce gas leakage. Conversely, using a Veress needle to preinflate allows the telescope cannula to be placed through a smaller, trocar-induced hole without the need for suture but carries increased risks of iatrogenic trauma.
Chelonians Because of the constraints of the chelonian shell, it is seldom possible to place the telescope and ports where established protocols would suggest. There are two major approaches, depending on the size of the animal. For larger chelonians,
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CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery the telescope and instruments may all be inserted through one prefemoral fossa (Figure 14-19), whereas in smaller animals, the telescope and instruments may be placed through one or both fossae (Figure 14-20). There are advantages and disadvantages to both approaches. Placing all instrumentation through a single fossa enables the surgeon to control both instruments, even in large animals, but convergence is reduced because of the acute angles involved (often 30 degrees or less): instruments run more parallel, which makes their coordinated use more difficult. Nevertheless, compared with a bilateral fossa technique, a unilateral approach is less invasive in that only a unilateral surgical approach is required; in addition, it enables the animal to be positioned in lateral recumbency, which may aid organ visualization. A single surgeon can use both prefemoral fossae in smaller animals, but here the angle
FIGURE 14-19 Two 6-mm threaded cannulae placed through the same prefemoral fossa in an adult Aldabra Tortoise (Aldabrachelys [Geochelone] gigantea). The close placement of separate instruments makes triangulation more difficult because of their parallel orientation. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
of triangulation is often obtuse (90 degrees to 180 degrees), again making coordinated instrument manipulation more challenging. If the target structure is cranial to the bladder and the chelonian is less than 20 kg, it is often preferable for one instrument and telescope to be inserted through one prefemoral fossa while the second instrument is inserted through the contralateral fossa (see Figure 14-20). For such procedures, the animal is in dorsal recumbency and the advantage is that instruments can be more easily triangulated within the cranial to midcoelom. However, in larger chelonians, it can be difficult to impossible for a single surgeon to operate through both prefemoral fossae simultaneously, and in such cases, a second surgeon is required to operate through one fossa. The endosurgical approach to caudal structures (e.g., bladder, kidney, adrenal, or gonad) is more problematic because it is often difficult to access the same structure simultaneously from both fossae unless a significant angle-deflected endoscope is used (e.g., 90-degree). Therefore where a caudal structure is the focus of the procedure, insertion of telescope and instruments through a single prefemoral fossa may be preferable. In such cases, the chelonian is generally positioned in dorsal or lateral recumbency, which often provides greater accessibility because the intestines and bladder fall to the more dependent areas of the coelom. This approach is easier in those animals with a large prefemoral fossa; nevertheless, the close placement and parallel nature of instrumentation can make triangulation more difficult. In addition, it is often easier (especially in smaller animals) to make a single large prefemoral incision for the insertion of all instruments rather than place three cannulae adjacent to one another (Figure 14-21). Insufflation is seldom essential because of the noncollapsible nature of the chelonian shell; therefore endoscopic devices can still be used through an incision without the need for cannulae.
Oophorectomy of Immature Females. The only publication to date that describes a truly endosurgical coelioscopic procedure in a reptile involves oophorectomy in immature, hybrid
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FIGURE 14-20 A, Endoscopic view of the caudal coelom demonstrating the bladder (b) and right ovary (o) as seen through a left prefemoral approach in a Box Turtle (Terrapene carolina). In this example, an aspiration needle (arrow) has been placed through the same left fossa and is being used to perform cystocentesis. B and C, Endoscopic views of the cranial coelom and liver (l) of another Box Turtle with ascites, as seen through the left prefemoral fossa. Biopsy forceps (f) and irrigation/suction cannula (i) have been introduced through the right fossa, which provides greater instrument triangulation. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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SECTION II • ADVANCES IN ANESTHESIA, SURGERY, AND ANALGESIA Galapagos Tortoises (Geochelone [Geochelone] nigra) with the use of 5-mm instrumentation.13 However, there is no reason why this same technique could not be applied to smaller chelonians with suitably sized instrumentation. In addition, this technique provides a model for other possible endosurgical procedures. The paired, immature ovaries reside in the caudodorsal coelom, in close association with the retrocoelomic kidney. The bladder obscures the contralateral ovary; thus an endosurgical approach must be repeated on each side, at least in the Galapagos tortoise. With the animal in lateral recumbency, a prefemoral approach to the coelom is made to accommodate the telescope and two instruments via a single incision (see Figure 14-21). Cannulae are generally not helpful because the instruments are so closely aligned and insufflation is not required. The telescope is positioned and held by a surgical assistant so that the view of the ovary is maintained. The immature ovary is lifted away from the serosal surface of the caudodorsal shell and kidney with Babcock or Kelly forceps, and monopolar scissors are used to dissect the ovary free from its mesovarian attachments (Figure 14-22). The prefemoral incision is closed routinely, and the procedure is repeated on the opposite side.
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FIGURE 14-21 Surgical view of a juvenile Galapagos Tortoise (Geochelone [Geochelone] nigra) undergoing endoscopic oophorectomy. Note that the telescope (t), handled by an assistant, as well as the grasping forceps (f) and radiosurgical scissors (s), operated by the primary surgeon, have all been introduced via a single prefemoral incision rather than through separate cannulae. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-22 Endoscopic left oophorectomy in a juvenile Galapagos Tortoise (Geochelone [Geochelone] nigra) with all instrumentation inserted through the left prefemoral fossa. A, Normal, immature left ovary (o) suspended from the caudodorsal body wall by a short mesovarium ligament (m). B, Grasping forceps (f) are introduced and used to grasp the mesovarium (m) but not the friable ovary (o). C, The mesovarium (m) is stretched by moving the forceps (f) cranially, while radiosurgical scissors (s) are used to incise through the suspensory ligament. D-F, Dissection through the mesovarium (m) continues using forceps (f) and scissors (s) until the ovary is dissected free and can be removed through the prefemoral incision. The incision is closed before the procedure is repeated via the right prefemoral fossa to remove the contralateral ovary. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery Oophorectomy of Mature Females. By virtue of the extensive mesovarian found in mature females, an endoscopeassisted procedure is practical in animals weighing a few hundred grams to 100 kg or more (Figure 14-23).13,14 With the chelonian in dorsal recumbency, a unilateral surgical approach to the coelom is made via one prefemoral fossa. The telescope is inserted into the coelom and used to locate the ipsilateral ovary. Then, the telescope is used to guide atraumatic forceps
(or even long hemostats in small chelonians) so that the interfollicular tissue is grasped and gently elevated to the skin incision. Once the first follicle is exteriorized, the telescope is no longer required because the ovary is carefully manipulated out of the coelom. Once the entire ovary is exteriorized, oophorectomy proceeds with the use of traditional techniques. The same procedure is repeated for the contralateral ovary, but it is usually not necessary nor recommended to remove the oviducts
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F FIGURE 14-23 Endoscope-assisted oophorectomy in an adult Red-eared Slider (Trachemys scripta elegans). A, After a prefemoral approach to the coelom, the ipsilateral ovary is located and retracted to the incision with the use of the telescope (t) and 3-mm atraumatic forceps (f). B, Endoscopic view of the caudal coelom demonstrating the ovary and three large ova (o), closely associated with the bladder (b) and intestine (i). C, Endoscopic view of 3-mm atraumatic forceps (f) being used to grasp the interfollicular tissue. D, Endoscopic view of the ovary being gently retracted toward the prefemoral incision. E, External view (taken using the telescope) demonstrating the first two follicles of the ovary exteriorized through the prefemoral incision. F, Continued manipulation to exteriorize the whole ovary precedes surgical oophorectomy with the use of radiosurgery. In most animals, the contralateral ovary can also be removed through the same prefemoral incision. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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unless diseased. In most species, both ovaries can be removed from the same incision; however, in some terrestrial tortoises with particularly restrictive prefemoral fossae, it may be necessary to perform a bilateral procedure. The prefemoral approach is closed routinely. This technique has several advantages over traditional plastronectomy, namely, a less invasive soft tissue approach instead of a bony approach, and faster healing.
Orchidectomy. Researchers have developed a similar approach for safe and effective orchidectomy, in red-eared sliders (Trachemys scripta elegans) and desert tortoises (Gopherus agassizii).15 The animal is again positioned in lateral recumbency and, after prefemoral coeliotomy, a surgical assistant identifies and maintains a clear view of the testis (Figure 14-24). The endosurgeon then uses Babcock or Kelly forceps to grasp and elevate the testis away from the kidney and epididymis to expose the mesorchium and associated vessels. Both monopolar radiosurgery and vascular clips have been used to ensure hemostasis before scissors are used to dissect the testis free (Figure 14-25). At least in the Red-eared Slider, it is possible to remove both testes via a unilateral prefemoral approach; however, in the desert tortoises a bilateral approach was necessary.
Lizards The most useful entry points for lizard diagnostic endoscopy also apply when instrument ports are considered. It is particularly important to remember that the standardized placement of cannulae through the linea alba cannot be applied to most lizards caudal to the umbilicus because of the presence of the midline abdominal vein; however, placement of a midline cannula, caudal to the umbilicus, is certainly practical and often preferred, particularly in iguanids (Figures 14-26 and 14-27).
Orchidectomy. With the iguana in right lateral recumbency, the telescope and protection sheath are inserted, just lateral to the ventral midline, close to the anastomosis of the left and right pelvic veins as they form the ventral abdominal vein (see Figure 14-26, C and Figure 14-28, B). The first cannula is placed cranial to the telescope, just caudal to the last rib, while the second cannula is placed caudal to the anastomosis of the pelvic veins in the ventral midline. Grasping forceps are inserted through one cannula and used to elevate the testis, while scissors (attached to monopolar radiosurgery device) are inserted through the other cannula and used to coagulate and cut through the mesorchium and associated vessels (Figure 14-29). In larger iguanas, bipolar forceps are used to coagulate blood vessels before sharp dissection. The testis is extracted through the forceps cannula hole, which can be enlarged, if necessary. The cannula holes are closed with a single suture or tissue adhesive. The iguana is rotated into left lateral recumbency, and using the same entry sites, the endoscopist repeats the procedure for the second testis.
ENDOSCOPY TRAINING The ability to perform endosurgery is not innate, and training is certainly required. Fortunately, various continuing education courses offer training in the United States and, less commonly, elsewhere. The Association of Reptilian and Amphibian Veterinarians (www.arav.org) regularly offers a 4-hour introduction to reptile endoscopy at its annual conference. In addition, the University of Georgia offers a 2-day course in reptile/avian, and another in small mammal endoscopy every year, with more advanced endosurgery courses offered intermittently (www.vet.uga.edu/CE/).
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elegans). B, Close-up of the surgical site. Note that the assistant controls the camera and telescope (t) while the primary surgeon uses 3-mm grasping forceps (f) and a vascular clip applicator (v) to perform the orchidectomy. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
CHAPTER 14 • Endoscope-Assisted and Endoscopic Surgery
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FIGURE 14-25 Endoscopic orchidectomy in the Red-eared Slider (Trachemys scripta elegans) via a unilateral prefemoral incision. A, View of the left testis (t) and epididymis (e) closely associated with the kidney (k) and renal vein (v). The descending colon (c) and caudal lung (l) are also visible. B, 3-mm Kelly forceps (f) are introduced and used to grasp the testis (t). C, The forceps are angled to retract the testis (t) cranially away from the epididymis (e) to expose the mesorchium (m) and associated vascular supply. D-F, Orchidectomy using vascular clips. A vascular clip applicator (v) is introduced and a single clip (arrow) is placed across the mesorchium (m), between the testis (t) and the epididymis (e), before the testis is dissected free using 3-mm scissors (s). G-I, Orchidectomy using radiosurgery. While the testis (t) is retracted away from the epididymis (e), monopolar scissors (s) are used to coagulate the mesorchial vessels (m), before the testis is dissected free and removed with forceps (f). After orchidectomy, the adrenal gland (a) can be seen. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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possible cannula insertion points (x) for performing multiple-entry endosurgery in lizards. The positions of the vertebral spine (v), last rib (r), ventral abdominal vein (av), and pelvic veins (pv) have been shown to indicate anatomic landmarks that should be appreciated. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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FIGURE 14-27 A, A primary surgeon and assistant performing endosurgery in a Green
Iguana (Iguana iguana). B, Close-up of the surgical site demonstrating the placement of the sheathed telescope with insufflation line attached (t) and a 3.5-mm cannula (c). (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
Surgeon Radiosurgery or laser
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FIGURE 14-28 A, General schematic and orientation
for performing endosurgical orchidectomy in an iguanid. As an alternative, positioning aids can be used to support the telescope and camera, allowing the monitor to be moved in front of the surgeon. B, Diagram illustrating the use of an assistant to support the telescope and camera (t), while the primary (right-handed) surgeon uses forceps (f) in the left hand and monopolar scissors (s) in the right hand to perform endosurgery within the dorsolateral coelom. (Art by Kip Carter [UGA], © University of Georgia Research Foundation, Inc.)
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FIGURE 14-29 Endoscopic orchidecto-
my in a Green Iguana (Iguana iguana). A, View of the dorsal coelom showing the right testis (t) and closely associated renal vein (v). B, Forceps (f), introduced through a caudal cannula, are used to grasp and elevate the testis (t) away from the body wall. C, With the testis (t) elevated away from the renal vein (v), monopolar scissors (s) are used to coagulate and cut across the mesorchium. D, The freed testis (t) is then retracted to the cannula (c), which is slid up the shaft of the forceps before the testis is removed through the cannula hole. If the testis is large, hemostats can be used to temporarily stretch the cannula hole to facilitate removal. (Courtesy Dr. Stephen J. Divers, University of Georgia, Athens, Ga.)
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ACKNOWLEDGMENTS The author would like to thank Karl Storz Veterinary Endoscopy and, in particular, Dr. Chris Chamness, Mike Bateman, and Dan McMahon for supporting endoscopy research, development, and training at the University of Georgia. In addition, the author is indebted to Drs. Scott Stahl, Charles Innis, Sam Rivera, Chris Hanley, Jason Norman, Emi Knafo, Randon Feinsod, Justin Oguni, Joe Flannagan, Heather Barron, Johanna Mejia-Fava, Jörg Mayer, Rodney Schnellbacher, and Laila Proenca for their collegiality and assistance in various endoscopic ventures at the University of Georgia.
REFERENCES 1. Lagares-Garcia JA, Bansidhar B, Moore RA. Benefits of laparoscopy in middle-aged patients. Surg Endosc 2003;17:68-72. 2. Yu SY, Chiu JH, Loong CC, et al. Diagnostic laparoscopy: indication and benefit. Zhonghua Yi Xue Za Zhi (Taipei) 1997;59:158-163. 3. Lhermette P, Sobel D. BSAVA manual of canine and feline endoscopy and endosurgery. 1st ed. Cheltenham, England: British Small Animal Veterinary Association, 2008. 4. McCarthy TC. Veterinary endoscopy for the small animal practitioner. St Louis: Elsevier, 2005. 5. Tams TR, Rawlings CA. Small animal endoscopy. 3rd ed. St Louis: Elsevier, 2011. 6. Divers SJ. Endoscopy and endosurgery. Vet Clin North Am Exot Anim Pract 2010;13:171-331.
7. Divers SJ. Reptile diagnostic endoscopy and endosurgery. Vet Clin North Am Exot Anim Pract 2010;13:217-242. 8. Divers SJ. Endoscopy equipment and instrumentation for use in exotic animal veterinary medicine. Vet Clin North Am Exot Anim Pract 2010;13:171-185. 9. Ternamian AM, Deitel M. Endoscopic threaded imaging port (EndoTIP) for laparoscopy: experience with different body weights. Obes Surg 1999;9:44-47. 10. Hernandez-Divers SJ. Minimally-invasive endoscopic surgery of birds. J Avian Med Surg 2005;19:107-120 11. Hernandez-Divers SJ. Endosurgical debridement and diode laser ablation of lung and air sac granulomas in psittacine birds. J Avian Med Surg 2002;16:138-145. 12. Hernandez-Divers SJ. Diode laser surgery: principles and application in exotic animals. Semin Avian Exot Pet Med 2002;11:208-220. 13. Knafo SE, Divers SJ, Rivera S, et al. Sterilization of hybrid Galapagos tortoises (Geochelone nigra) for island restoration: Part 1 female endoscopic oophorectomy under ketamine-medetomidine anaesthesia. Vet Rec 2010;168:47-51. 14. Innis C, Hernandez-Divers SJ, Martinez-Jimenez D. Coelioscopicassisted prefemoral oophorectomy in chelonians. J Am Vet Med Assoc 2007;230:1049-1052. 15. Innis CJ, Feinsod R, Hanlon J, et al. Coelioscopic orchiectomy can be effectively and safely accomplished in chelonians. Vet Rec 2013; 18;172:526. Epub 2013 Apr 4.