Small Animal Laparoscopy and Thoracoscopy. Группа авторов

decrease in morbidity related to visceral and vascular injury during trocar placement; and risk reduction of postoperative wound infection, hernia formation, and elimination of multiple trocar site closures [12]. To date, there have been several systematic reviews and metanalyses describing the comparison of conventional laparoscopic and single‐port procedures, as well as a handful of prospective, randomized controlled trials [8,13–19]. Although a broad generalization cannot be made; there is a general trend toward shorter hospitalization stays, less need for postoperative analgesia, and lower pain scores associated with single‐port surgery when compared to conventional laparoscopy.

      It should also be noted that within the human literature, including both clinical case series and laboratory‐based skill acquisition studies, evidence has demonstrated unique requirements of single‐port surgery. Skill sets and ergonomic demands cannot be directly adapted from existing laparoscopic experience, and the implementation of an evidence‐ and competency‐based single‐port training curriculum is necessary to ensure appropriate training of future single‐port surgeons [19]. An evaluation of the learning curve for the single‐port ovariectomy for a board‐certified veterinary surgeon has also been reported [20]. The study described that the learning curve for single‐port ovariectomy was short (optimal performance after approximately eight procedures), and proficiency can be achieved within a definable period.

Adoption into Veterinary Laparoscopy

Within veterinary laparoscopic surgery, reducing the number of portals of entry has been a concept embraced by many veterinarians for a number of common techniques. In 2009, Dupre et al. described the one portal operating laparoscopic ovariectomy (OVE) using a 10‐mm telescope that incorporates a working channel that can accommodate 5‐mm instruments [21]. An array of two‐port laparoscopic‐assisted techniques, including gastropexy [22], cystopexy [23], urinary calculi removal [24], and cryptorchidectomy [25], have also been described. These two‐port techniques enabled many common elective procedures to be done routinely by veterinary laparoscopic surgeons. It was only recently that many of the two‐port procedures in veterinary laparoscopy took a leap toward the single‐port platform in which multiple instruments, as well as the telescope, are consolidated to one point of entry for completion of the entire procedure. The earliest abstract reports on laparoscopic single‐port veterinary techniques that did not use an operating laparoscope emerged in 2011 [25, 26]. The single‐port platform gained rapid popularity among veterinary laparoscopic surgeons. Shortly after the initial single‐port abstracts, a total laparoscopic ovariectomy using standard rigid instrumentation was described [27] using a commercially available single‐port device (SILS [single‐incision laparoscopic surgery] port, Covidien, Mansfield, MA). Shortly after, the SPA ovariectomy technique was reported [28]. Other single‐port devices, as well as novel bent and articulating instruments, emerged as feasible instrumentation that could be used in veterinary single‐port laparoscopy [29]. More recently, other techniques using the LESS approach have been reported and are summarized in Table 6.2.

Table 6.2 Examples of procedures that have been adopted with single‐port, single‐incision, and LESS in clinical cases within veterinary surgery.

	References
Ovariectomy in dogs and cats	[20, 27, 28,30–35]
Ovariohysterectomy	[36]
Cryptorchidectomy	[37, 38]
Intestinal surgery	[34,39–44]
Adrenalectomy	[45]
Splenectomy	[46, 47]
Artificial urethral sphincter placement	[48]
Gastropexy	[22,49–52]
Cholecystectomy	[53–55]
Ureteronephrectomy	[56]

      Despite the wider adoption of single‐port surgery in veterinary medicine, there has been little comparative analysis of the potential advantages or disadvantages to conventional, multiport laparoscopic surgery. A retrospective case series reviewed multiport and a SPA system for a variety of laparoscopic procedures [57]. Surgical time and intraoperative complications were found reduced for patients undergoing single‐port surgery. Conversely, a prospective, randomized trial comparing multiport and single‐port ovariectomy demonstrated that surgical difficulty was subjectively higher for single‐port surgery [58]. Complications were, however, not identified in any case (0/10). Given the additional technical challenges, different and often expensive disposables required, and potentially longer learning curve, additional study is warranted on the value and safety of LESS over existing techniques.

Access Methods for Single‐Port Surgery

      Operative Laparoscopy and Advanced Operative Laparoscopy

This uses a traditional simple operative endoscope that incorporates a 5‐mm working channel through which instruments can be passed (Figure 6.1). Advanced operating laparoscopes include a triangulating operating platform, 30 such as the SPIDER surgical system (TransEnterix Surgical Inc, Durham, NC), which gives a surgeon multiple independent, flexible arms that can be extended through a rigid operating laparoscope shaft.

Single‐Port Access

This uses a single skin incision (usually at the umbilicus), but separate individual facial incisions through which traditional trocar–cannula assemblies are passed through the abdominal wall (Figure 6.2). SPS has also been adapted for a paramedian approach (laparoscopic‐assisted gastropexy) [51], transvaginal approach (ovariectomy) [59], and retroperitoneal access (adrenalectomy) [45, 60].

Figure 6.1 This operating laparoscope (Karl Storz Endoscopy, Goleta, CA) incorporates a 5‐mm working channel through which 5‐mm rigid instrumentation can be passed.

      Source: © 2014 Photo Courtesy of KARL STORZ GmbH & Co. KG.

Figure 6.2 Single‐port access laparoscopy is performed by the passage of three separate cannulae through one skin incision but separate fascial incisions.

Commercially Available Single‐Port Devices

These devices have been specifically manufactured for single‐port surgery and are intended to be inserted through a single full‐thickness abdominal incision. These commercially available SPA devices can have multiple 5‐ to 12‐mm access channels to