Small Animal Laparoscopy and Thoracoscopy. Группа авторов

intracorporeal knot tying, and intracorporeal suturing. A variety of needle holders and suture assist devices are available for this purpose. The most common diameter needle holders used are 5 mm, although 3 mm diameter instruments are available for smaller patients. Endoscopic needle holders most commonly come with straight handles (Figure 4.11) rather than ring handles to provide a more ergonomic motion while manipulating suture and needle. The handles lock via a ratchet mechanism.

Figure 4.11 KOH macro‐endoscopic needle driver with straight handle. Used with a wide range of suture and needle sizes; from 0/0 to 7/0.

      Source: © 2014 Photo courtesy of KARL STORZ SE & CO, KG.

Figure 4.12 Endoscopic needle holders (from top to bottom): straight jaws, jaws curved to the left, jaws curved to the right, Szabo‐Berci needle holder (“Parrot Jaw”), and Szabo‐Berci assistant needle holder (“Flamingo Jaw”).

      Source: © 2014 Photo courtesy of KARL STORZ SE & CO, KG.

The traditional endoscopic needle holder (see Figure 4.11) has straight jaws with tungsten carbide inserts to prevent needle slippage. It is used in combination with grasping forceps to pass the needle from one side of an incision to the other and to tie knots. Needle holders with right‐handed and left‐handed curved jaws (Figure 4.12) are used as a pair to pass the needle and tie knots. The curved configuration helps with loop formation and grasping of the suture end while tying knots.

      Although marketed for human and large animal endoscopic surgery, the Szabo‐Berci needle holder pair (see Figure 4.12) is also designed to facilitate easier needle passage, loop formation, knot tying, and grasping of tissues. The Szabo‐Berci needle holder “Parrot Jaw” has a broad, flat jaw with a downward curve and blunt tips. Its counterpart, the Szabo‐Berci Assistant needle holder “Flamingo Jaw,” has a narrower, tapered jaw with pointed tips for grasping of suture ends through a loop. These needle drivers are designed to accommodate a fairly limited range of needle and suture sizes.

      A self‐righting needle holder is available that automatically places a curved needle in the correct vertical position for suturing. The needle holder has a single‐action mechanism with a fixed, broad jaw with cut‐outs that fit with the convex surface of a curved needle. The opposing jaw is narrow and meets with the concave surface of the needle when the jaws are closed to rotate the needle against the fixed jaw and hold it perpendicular to the axis of the instrument. Self‐righting needle holders negate the need for a second instrument to position the needle and thereby facilitate more efficient needle handling during suturing. They also prevent needles from twisting within the grasp of the instrument during passage through tissues. However, the suture is easily damaged if grasped with the jaws of self‐righting needle drivers, which is an important limitation.

Figure 4.13 Endo stitch device with suture loaded into jaws.

      Source: Copyright © 2013 Covidien. All rights reserved. Used with the permission of Covidien.

The Endo Stitch device (Covidien, Mansfield, MA) (Figure 4.13) was designed to avoid needle handling during intracorporeal suturing. A double‐pointed needle with centrally swaged suture is passed from one jaw to the other. This device will pass the suture through tissue, as well as through suture loops, to tie knots without the need to reload and reposition the needle. It comes in a 10 mm diameter size only.

A needle must be passed carefully through the instrument cannula to prevent damage to the gaskets within. One way to avoid damage is by the use of an introducer sleeve, a valveless cannula that fits within a regular port cannula but is still wide enough to allow passage of a needle, suture, and other knot‐tying equipment (Figure 4.14). However, in small animals with small cannula sizes, it is often more practical to simply remove the cannula from the body wall, thread it onto the needle driver, grasp the needle and suture, introduce them through the incision, and thereafter replace the cannula into the incision. Suture knots can be tied intracorporeally or extracorporeally. Intracorporeal knot tying using needle holders and graspers requires some practice for a surgeon to become proficient at this skill. The Suture Assistant (Ethicon Endo‐Surgery, Somerville, NJ) is a 5 mm diameter device that deploys pretied suture intracorporeally for simple interrupted suture patterns. Cartridges are available with different sizes and types of suture most commonly used for soft tissue closure. After the suture is loaded onto the Suture Assistant, it is passed into the body cavity. The needle is driven through the tissues with needle holders and then is passed through a pretied loop at the end of the device. Deployment of the device produces a secure intracorporeal knot.

It is often easier for an endoscopic surgeon who is starting to place endoscopic sutures to tie knots extracorporeally. Extracorporeal knot tying can be performed using standard suture material or using pretied loop sutures, such as the Endo‐Loop Ligature. With standard suture, a single half‐hitch, double half‐hitch (i.e. surgeon's throw), or modified Roeder knot (for details, see Chapter 2) is created outside of the body and then is pushed through the cannula using a knot pusher. A knot pusher (Ethicon Endo‐Surgery) is a plastic tube with a conical end through which the suture ends pass. The knot pusher then is used to slide the knot into the body cavity by pushing down on the knot while simultaneously pulling up on the suture ends. After placement, a half‐hitch knot can be corrected to an overhand throw. Koeckerling Knot Tiers (Karl Storz GmbH, Tuttlingen, Germany) (see Figure 4.14) are 5‐mm instruments on long shafts with a notch and hole at the end; they serve the same purpose as a knot pusher. Endoscopic Babcock forceps can also be used to advance and secure an extracorporeal knot.

Figure 4.14 Suture assist devices (from top left to bottom right): Koeckerling knot tier, introducer sleeve, and EndoLoop ligature.

      Source: © 2014 Photo courtesy of KARL STORZ SE & CO, KG.

      The Endo‐Loop Ligature (Karl Storz GmbH) (see Figure 4.14) was developed for use over free vascular pedicles. It consists of a pretied loop of suture with a Roeder knot loaded into a single‐use plastic cannula. After the loop is placed around the desired tissue, the cannula is snapped at a prescored line. The most distal end is used as a handle to tension the suture while the rest of the cannula serves as a knot pusher to close the ligature around the pedicle.