(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 enable an array of instrumentation to enter the abdominal cavity (Figure 6.3).
Principles of Single‐Port Surgery
The principles of single‐port surgery are very similar to those of conventional multiport laparoscopy, although differences exist associated with the way triangulation is achieved. Having one point of entry inherently prevents the traditional principles of instrument triangulation. The close proximity of the instruments and optics, both intra‐abdominal and extra‐abdominal, causes the surgeon to perform the procedure with suboptimal working space intra‐abdominally. This ultimately causes increased technical complexity for any procedures because of inadequate triangulation, a compromised field of view, inadequate exposure, and frequent instrument collisions, which all occur as a result of the common entry point for the camera and instruments [29]. Single‐port laparoscopy has been able to somewhat overcome this lack of triangulation by using angled optical telescopes, crossing instruments, or bent and articulating instruments. This novel arrangement of both the optics and instruments creates more internal and external working space, allowing for some triangulation that prevents instrument crowding. Although standard instruments can be used for single‐port surgery, numerous instruments and devices have been developed to simplify and make single‐port surgery more user friendly.
Figure 6.3 The SILS (single‐incision laparoscopic surgery) port (Covidien, Mansfield, MA) allows the placement of three cannulae and has a separate CO2 insufflation port.
Access in Single‐Port Surgery
The devices and equipment used for single‐port surgery can be broadly classified as: (i) specifically manufactured devices for single‐port surgery, (ii) standard instruments and trocar–cannula assemblies used for conventional laparoscopy inserted through one skin incision, or (iii) innovative adoptions of existing equipment not primarily intended for laparoscopy.
Insertion Techniques for Specifically Manufactured Single‐Port Devices
GelPOINT Access System (Applied Medical Inc., Rancho Santa Margarita, CA)
SILS Port (Covidien; Figures 6.3 and 6.4)
A 2‐ to 3‐cm mini‐laparotomy is created in advance for insertion of the port. To insert this single‐port device, a small amount of sterile lubricant is applied to its soft base (Video 6.2). The port is inserted into its 2‐ to 3‐cm abdominal incision by clamping two curved Rochester‐carmalt forceps at the base in a staggered fashion. Varying techniques have been described for insertion into the incision: it can be performed without abdominal wall countertraction or with a form of countertraction such as grasping the facial edges with two large rat‐toothed tissue forceps, Army‐Navy retractors, or stay sutures. Regardless of traction, the tips of the Rochester‐carmalts are directed into the incision in a cranial direction toward the diaphragm or away from any underlying viscera. When the base is seeded within the incision, the clamps are then released to allow the bottom portion of the port to expand and fit snugly within the incision. Three 5‐mm cannulae (supplied with the port) are then partially inserted into the three inner cylinders with the aid of a 5‐mm blunt obturator. The SILS port is also supplied with a 12‐ to 15‐mm trocar–cannula assembly to allow larger instruments to be inserted with two other 5‐mm cannulae. The heights of the cannulae are staggered to minimize cannula contact (Figure 6.5). Insufflator tubing is then attached, and the abdomen is insufflated to 8–10 mmHg with carbon dioxide using a pressure‐regulating mechanical insufflator. Once insufflation is complete, the three canulae can then be inserted deeper into the port. The multitrocar port can be positioned to have the three 5‐mm cannulae at the 12, 4, and 8 o’clock positions relative to the surgical site, although any arrangement is possible. Advantages of this port include the relative ease of insertion and reinsertion during a procedure and its ability to fit snugly within the incision, preventing loss of pneumoperitoneum.
Despite being sold as single‐use instruments, it is not uncommon to reuse various minimally invasive surgery devices in veterinary medicine for economic reasons. Multiple studies have been conducted to test the reusability of the SILS devices [61–63]. Results indicate that the ports can be decontaminated and sterilized by ethylene oxide and hydrogen peroxide vapor for repeated use. In one study [62], the foam component was found to have positive light growth after eight uses. The reuse of the SILS ports appears to carry a low risk of infection to the patient; however, the mechanical stability of the ports
