The future

Abstract

Practical relevance:

Laparoscopic surgery minimizes tissue trauma and speeds recovery, but its uptake into veterinary clinical practice has been slow.

Clinical challenges:

Laparoscopy is distinctly different from traditional open surgery and a reduced working area and loss of depth perception are among the challenges that the surgeon must get to grips with. Indeed, it is often lack of the necessary skills, rather than the cost of equipment, that presents the greatest obstacle.

Audience:

This article is aimed at practitioners keen to embrace minimally invasive surgery and advises on how to develop excellence in laparoscopic skills. It makes the case for simulation training and outlines methods that can be instituted in practice at low cost and with comparatively little time expenditure. It also describes technological advances that have already increased the success of veterinary ‘keyhole’ surgery, as well as those that look promising for the future.

Evidence base:

Simulation training has been an intense area of research and publication within the past 15 years. This article draws on that evidence base and the experience gained by the author and her research team, which is at the forefront of efforts to develop laparoscopic training for veterinarians.

Amplifying the uptake in ‘keyhole’ techniques

In today’s world of high-tech medical advances, it is common for the general public to demand that surgical procedures on their pets be as safe as for people, and that surgically related pain is minimized. Minimally invasive ’keyhole’ surgery leads to less pain, shorter hospitalization time and early ambulation when compared with traditional surgery.^1,2

Endoscopic surgery was introduced in veterinary medicine more than 20 years ago, but the technology has been slow to have been embraced. The delay in incorporating minimally invasive surgery into general practice has likely been a result of the technical challenges associated with this surgery (see box), more so than the associated equipment costs.

These challenges can be overcome, rendering the veterinarian a successful laparoscopic surgeon, by two mechanisms: technological advances and skills training. Until recently, focus was mainly placed on the first of these and, certainly, recent technological advances have the ability to facilitate surgery, enabling the surgeon to undertake new procedures and to increase the sophistication of the surgical procedure. However, technology alone, without appropriate skills training, will not render excellence.

Laparoscopic skills training

Traditionally, veterinarians wanting to incorporate minimally invasive surgery into their clinical practice have attended a short course. After this, ‘training’ has been provided by performing surgeries of gradually increasing challenge levels in clinical practice, often including humane society work pro bono. This approach is, however, fraught with concern as any practice on live animals is increasingly raising ethical questions. In addition, the surgeon who wants to achieve excellence in skills rapidly and at a high level, especially suturing skills, may not have been able to develop consistent skills within a reasonable time frame.

In this author’s opinion, the ideal training in laparoscopic basic skills should be separate from clinical practice, and independent of the number and type of cases seen in the surgeon’s clinic. This allows veterinarians to develop these skills prior to, or in the early phase of, clinical surgery, leading to greatly increased patient safety. Simulation training provides training outside the operating room, allowing the surgeon to maintain and develop high-level skills in the face of an inconsistent case load, and without placing surgery outcomes in live animals at risk.

Simulation training has been an area of intense research within the past 15 years and a comprehensive review of the evidence of benefits is outside the scope of this article. However, the fact that simulation training, through the Fundamentals of Laparoscopic Surgery (FLS) program, is now required by the American College of Surgeons in order for surgery residents to become board exam eligible, speaks to its unequivocal benefits. It has been shown without doubt that the skills gained in simulation training labs are transferred into the operating room, benefitting both patient and surgeon. Importantly, it has also been shown that the skills associated with laparoscopy are specific, and these are not improved by performing open surgery. Therefore, laparoscopic skills need to be specifically learned using laparoscopic technology.

The veterinary community has only recently become interested in skills as an important foundation for successful minimally invasive surgery. The author’s research group at Washington State University (WSU) has developed the first laparoscopic training laboratory, open for use by veterinarians within and outside of the institution – the Veterinary Applied Laparoscopic Training (VALT) laboratory (Figure 1). The training curricula and assessments used in the VALT lab have been validated.^3–5 Through this work it has been noted that the novice may improve manual laparoscopic skills rapidly, ³ and that a 10 h VALT training curriculum equips the majority of veterinarians with manual skills levels corresponding to that of the FLS competency level. ⁵ It has also become evident that the curriculum provides skills development similar to that gained by actual laparoscopic surgical experience. ⁵ Ongoing research is under way to determine the best 10 h training curriculum for novices.

Figure 1

The Veterinary Applied Laparoscopic Training (VALT) laboratory at Washington State University. Courtesy of Henry Moore Jr, Washington State University, College of Veterinary Medicine

However, the VALT curriculum requires resources, including time, space and equipment, which may be limited for many practitioners. Therefore, outlined below is a form of simulation training that can be instituted anywhere at low cost and with little time expenditure.

Equipment

Laparoscopic training equipment is commercially available from many companies and in a variety of modalities, ranging from standard video box trainers to more sophisticated virtual reality systems (see page 44). Homemade versions of box trainers are now easy to construct, courtesy of today’s affordable high quality web cameras.

Figure 2

The LapSim Haptic System virtual reality trainer combines high-technological virtual reality exercises with haptic feedback. Courtesy of Surgical Science Inc, Americas Headquarters, Minneapolis, MN, USA

Figure 3

The ProMis augmented reality trainer is a combination of a physical box trainer and a virtual reality overlay offering many surgical exercises. © 2014 Photo courtesy of CAE Healthcare

Figure 4

(a) Simple homemade box trainer consisting of a plastic box from a department store. The cut-out areas are covered with a neoprene sheet in order to hide the instruments and models being worked on. (b) A webcam (c615 HD Webcam, Logitech, Newark, CA, USA), which has the ability to swivel, allowing a correctly orientated image, is fastened to the inside of the box trainer with Velcro. In addition, a LED light strip provides lighting, and is partially visible in the top of the picture. The photograph was taken from the back of the trainer, as if facing the user

Exercises

Some of the most important skills associated with laparoscopic technique, and indeed all surgical procedures, include ambidexterity and recognition of cues for depth perception. Together these enable bimanual precision and meticulous cutting. It has become clear from the VALT lab work that even experienced surgeons tend to lag in efficient use of their non-dominant hand, something easily rectified by simulation training. In addition, the surgeon should be able to use ligating loops, and perform extracorporeal knot tying and intracorporeal suturing. ⁷ One might argue that the latter tasks are uncommonly used in many basic veterinary surgical procedures. In the author’s opinion these skills enable the surgeon to competently handle many unexpected situations as they arise during surgical procedures. Competency also builds surgical confidence, which may influence the decision of whether to convert a laparoscopic procedure to open surgery. Possessing a higher skill level than the minimum requirements also removes an important obstacle to development of new techniques. ⁸

It is recommended that the novice starts with the five exercises included in the McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS),^5,9 which is used within the FLS program. These training exercises are outlined on page 45. In addition to the MISTELS exercises, the author and colleagues have noted important benefits in a variety of other exercises, which are beyond the scope of this article but have been presented elsewhere. ⁵ Currently, the VALT curriculum is studying the effects of incorporating basic skills and surgical skills exercises in virtual reality into the training program.

Assessments

Despite the unequivocal benefits of laparoscopic simulation training, surgeons busy in clinical practice or training programs may not perceive that they have time to invest in manual skills training. The VALT lab has noted that the more experienced surgeons are less inclined to spend time practicing. It is proposed that skills training should commence as early as possible in the surgeon’s laparoscopic career. Furthermore, it is likely that manual skills assessments are necessary to encourage trainees and to justify the money and time spent in training. A high-stakes test for human laparoscopic surgeons is already in place, the FLS program, and currently the VALT lab is investigating the possibility of offering a manual skills test to veterinarians as well. The aim is to reward those investing in simulation training and, ultimately, to benefit veterinary patients.

Technological advances

Laparoscopic devices and techniques

Single incision laparoscopic surgery

Traditionally, the laparoscopic approach is started by insufflation of the abdominal cavity with carbon dioxide through a Veress needle (closed insufflation) or through a cannula placed into the abdomen via a small incision (open insufflation, Hasson technique). Thereafter, one or more cannulae are placed at desired locations under direct visualization through the scope.

Devices for single incision laparoscopic surgery (SILS) have been reported recently in the veterinary literature, whereby a single incision is used for insertion of devices containing multiple portals.^10–12 Examples include the SILS Port (Covidien, Mansfield, MA, USA) and the EndoCone (Karl Storz, Goleta, CA, USA) (Figure 5). Common to these devices is that they do not require gas insufflation prior to insertion. The EndoCone has a removable steel cap which allows for exteriorization of intestines, and the foam SILS Port can be removed for exteriorizing organs and then replaced. These features allow for easy re-insufflation to inspect the surgical site before completing the surgery, which is not always the case in traditional laparoscopy-assisted surgery, where a port incision is extended to allow for organ exteriorization.

Figure 5

Single incision laparoscopic surgery devices. (a) The EndoCone has a removable bulkhead allowing for laparoscopy-assisted procedures. © 2014 Courtesy of KARL STORZ GmbH & Co KG. (b) SILS Port. Copyright © 2014 Covidien. All rights reserved. Used with the permission of Covidien

The main disadvantage with the single incision access techniques, regardless of device, is that the close clustering of instruments may cause instrument interference. So-called ‘clashing’,^10,11 and a fulcrum effect, may lead to crossing of instruments at the level of the body wall, resulting in the right hand instrument functioning on the left side and vice versa. For this reason, some of these devices are designed to be used with articulating or bent instruments (Figure 6), which may require additional expense and training to use. However, standard straight instruments have reportedly also been used with success in devices designed for special instrumentation.^10,12

Figure 6

Bent instruments are designed for use in single incision laparoscopy to avoid clashing of the instruments. © 2014 Courtesy of KARL STORZ GmbH & Co KG

Lift laparoscopy

Numerous human clinical and animal studies have shown that the traditional pressurized pneumoperitoneum created using carbon dioxide insufflation causes significant physiologic changes.^13–17 Though healthy cats are able to effectively compensate for the alterations in blood and airway pressure, ¹⁸ animals with underlying cardiopulmonary disease may not. As a result, it is generally accepted that the ideal patient for laparoscopic surgery is a healthy animal. However, the minimal surgical trauma associated with laparoscopic surgery may be particularly beneficial in animals with underlying disease.

Abdominal wall lift laparoscopy was developed in order to circumvent the physiologic changes of laparoscopy. During lift laparoscopy, the abdominal cavity is not pressurized, but air gains entrance through the ports and creates an isobaric pneumoperitoneum which allows working space for the laparoscopic instrumentation. The advantages of gasless laparoscopy are several and include absence of adverse cardiovascular hemodynamic changes, hypercapnia and adrenergic response associated with pressurized capnoperitoneum. ¹⁵ The disadvantage is that the lifting creates a tenting effect (in contrast to the dome shape of the pressurized abdomen) and an associated reduction in the working space in the abdomen. ¹⁹

A device for lift laparoscopy has been developed by the author’s research group, the LapLift (Figure 7), and its use in seven dogs and five cats has been reported. ²⁰ Lift laparoscopy was noted to confer some significant practical advantages, particularly for laparoscopy-assisted procedures. The lift device is easy to use, and is very atraumatic in its design. In several years of use at WSU, it has not been associated with complications such as splenic or bladder perforations, which are not uncommon with conventional entry. In fact, it has been estimated that up to 50% of laparoscopic complications are entry-related. ²¹ The most common adverse effect with lift laparoscopy is that omentum is caught with the lift, in which case the surgeon simply derotates the device, releases the omentum and reinserts the lift. Also, without the need for air-tight seals on ports, the surgeon has the freedom to use instruments of different sizes and the work space is also maintained during laparoscopy-assisted incisions. Furthermore, the device is amenable to being used in a SILS fashion.

Figure 7

LapLift device for abdominal wall lift laparoscopy in dogs and cats. The tip is rotated into a small ventral midline incision and tension is applied by either a rod suspending system or an articulated arm

Despite the suboptimal tenting effect, a randomized controlled blinded study of ovariohysterectomy performed with lift laparoscopy compared with capnoperitoneum reported similar surgery times, and the advantage of a reduced pain response. ²²

Natural orifice transluminal endoscopic surgery (NOTES)

In NOTES, a flexible endoscope or a working laparoscope and instrumentation is inserted through a natural orifice, and then transmurally into the abdominal cavity, often transvaginally or through the stomach. In an experimental study on dogs comparing NOTES ovariectomy with open or laparoscopic technique, NOTES was significantly more time consuming but resulted in a lower pain score than the other methods. ²³ However, a very steep learning curve and potentially higher tissue trauma^23,24 may impede the incorporation of this technique into many veterinary practices. A hybrid NOTES procedure has been assessed experimentally and in a canine case report, ²⁵ and may be less technically challenging.

Hemostatic devices

Several energy devices for hemostasis during laparoscopy have been made commercially available over the past 15 years. Monopolar radiofrequency type electrocautery can be used with standard laparoscopic instrumentation, using an adaptor connecting to most commercially available units used for open surgery. Ultrasonic devices such as the Harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, OH, USA) or AutoSonix coagulation device (Covidien) cause less thermal trauma than electrosurgery, ²⁶ and can effectively seal blood vessels up to 5 mm in diameter. ²⁷ However, the most popular are the LigaSure vessel sealing device (Covidien) and Enseal tissue sealer (Ethicon Endo-Surgery), which are able to permanently fuse vessels up to 7 mm in diameter. Both devices are feedback-controlled systems, whereby energy delivery is discontinued when sealing is completed; the tissue can then be transected with the same instrument. The seal-and-cut feature has greatly facilitated laparoscopic surgery by reducing instrument traffic, as the same instrument is often used for most of the procedure. Vessel sealing is safer and faster than other methods of hemostasis, as demonstrated in ovariohysterectomy in dogs. ²⁸

Though these devices were engineered to fuse the collagen and elastin of blood vessels, recent work has found them to be effective also for fusing other tissue types in small animals, such as uterine horns, ²⁹ small lung biopsies ³⁰ and bile ducts. ³¹

Another device that enables the surgeon to perform certain procedures that otherwise would not be safe to perform, such as endoscopic lung lobectomies and liver lobectomies, is the linear stapling–cutting device (eg, EndoGIA, Covidien). These instruments place three staggered rows of staples on either side of the cut-line, effectively sealing blood vessels and airways.

Suturing devices

Intracorporeal suturing is highly technically challenging, to the point where intense efforts have been made to find effective means of replacing laparoscopic knot-tying. A multitude of devices have been developed, but currently only a few have been evaluated in veterinary medicine.

Automated suturing device

A suture-assist device, Endo Stitch (Covidien) (Figure 8), has been reported on in the veterinary literature. ³² This device functions by passing the needle with attached suture material from one jaw to the other in a very controlled manner. The advantages when compared with conventional intracorporeal suturing include ease of needle position and management, and that the one device is carrying out the actions of two instruments (needle driver and grasper or dual needle drivers). The short needle length and inflexible positioning are, however, limitations of this device for thicker tissues and for certain defect locations. Recently, an articulated version of this device has been made available for application in SILS, perhaps improving versatility.

Figure 8

Endo Stitch suture-assist device. Copyright © 2014 Covidien. All rights reserved. Used with the permission of Covidien

Barbed suture

Several manufacturers have produced barbed suture (Figure 9) for knotless suturing. Barbed suture conveys important advantages for laparoscopic application. The knotless design is one of them, but of equal importance is the barbs’ ability to resist slippage along the suture material when continuous suture patterns are performed. These features are greatly facilitating intracorporeal suturing, and recent reports are a testimony to their budding popularity in veterinary medicine.^33,34

Figure 9

Barbed suture is designed for knotless closure and resists tissue sliding along the suture, features which greatly enhance its use in laparoscopy. Copyright © 2014 Covidien. All rights reserved. Used with the permission of Covidien

The combination of barbed suture and suture-assist device has likewise been explored, and appears to further facilitate intracorporeal suturing. ³⁵

Tumor-ablating devices

Clinical use of tumor-ablating devices has not been reported in cats. Such devices are often used for inoperable tumor treatment in people, not uncommonly for treatment of metastatic tumors in liver, lungs, kidneys and other organs. A plethora of technological advances is being made in this area, including radiofrequency ablation, microwave ablation, cryotherapy, high intensity focused ultrasound and laser ablation. A combination of endoscopic and ultrasound guided laser ablation of urethral transitional cell carcinomas has been reported in dogs, ³⁶ and appears successful when used by surgeons experienced in the technique, but would seem risk-filled for use in the feline urethra. Radiofrequency ablation of normal canine adrenal tissue has been experimentally studied, ³⁷ in order to prepare for clinical use in small animal adrenal neoplasia. Hypertension and sharp increases in norepinephrine were noted, and effective catecholamine blockade may have to be investigated prior to clinical use.

Key Points

• Success in minimally invasive surgery is dependent on the surgeon’s skills and access to instrumentation facilitating the procedure.

• Skills required for laparoscopic surgery are not practiced in, nor transferred by, open surgery.

• Simulation training can rapidly increase the surgeon’s skills to an advanced level.

• Box training is an effective, low-cost option for simulation training. ‘Homemade’ boxes can be quite useful training tools.

• Advanced training tools in virtual reality add a ‘fun factor’ and provide immediate performance feedback, which enhances training.

• Development of hemostatic devices for laparoscopic use has greatly facilitated laparoscopic surgery.

• Other devices and materials facilitating laparoscopic suturing, such as barbed suture, will lead to more widespread application of minimally invasive techniques in animals.

• Advanced surgical platforms, such as robotic surgery, have not yet been evaluated in the veterinary field but will likely appear within the next few years.