target="_blank" rel="nofollow" href="#ulink_6cd844c8-eac7-5255-8869-735fa4a811a1">Figure 2.24 Weston knot tying. (A). A right‐to‐left bite has been simulated. The needle end (green) is the post; the short (red) constitutes the loop end. The left hand is wrapping the suture around the dorsal thumb. (B). The loop end has crossed over the post, and the thumb and index finger meet and rotate down through the loop, grasping the loop end and bringing it up (posterior to anterior) through the loop to create a single throw. (C). The thumb remains positioned in the loop, and the throw is maintained at the dorsal thumb. (D). The left‐hand index and middle fingers, pointing upward (posterior to anterior direction), cross the strands by pushing the post from right to left and the loop from left to right. (E). The loop end is grasped by the left index and middle finger, which are used to pull the loop end in an anterior to posterior direction. (F). The loop end is passed under the left strand (post), and then it is grasped by the right hand and moved up again (posterior to anterior). (G). The right hand passes the loop end into the small triangular space that is formed by the two strands on the right of the thumb and the one strand to the left of the thumb. The thumb and index finger of the left‐hand grasp the loop end. (H). The Figure 8–shaped knot is pulled tighter by applying gentle and equal tension on both the post and the loop end. (I). Excessive tension on the loop (short) end will make the knot tumble, which will lock it, and the knot will not slip. Ensure that the loop end is not overtightened. The knot can now be slipped down and cinched with a knot pusher, which will tumble the knot and lock it. Additional throws are applied with intracoporeal knot‐tying technique.
Figure 2.25 Modified Roeder knot tying. The coloring is not fixed on the rope, but added to clarify post vs. loop end in this series. (A). A suture bite has been simulated. The needle end (green color) is the post; the red‐colored constitutes the loop end. (B). The loop end crosses posterior to the post and is then forming a single throw (C). The loop end is wrapped anterior to posterior 4 times around both ends (D). The loop end is passed around the loop end posterior to anterior below the last throw (E). Thus, the loop end forms a half hitch. (F). The loop end is thereafter passed (anterior to posterior) through the beginning loop hitch. (G). The completed knot ready to be cinched down with a knot pusher. (H). Cinched knot with no air.
Automated Suturing Devices
To address some of the difficulties associated with traditional intracorporeal suturing, several automated suture devices (ASDs) have been developed. One of the most commonly used models is the Endo Stitch (Covidien, Mansfield, MA; Figure 2.26), which has been shown to reduce laparoscopic suturing time up to 70% when compared to conventional intracorporeal suturing techniques. [21–24] The Endo Stitch is very user friendly and is available in a 38 cm long, 10 mm diameter model for laparoscopic use. A variety of suture materials can be used with the Endo Stitch, including braided lactomer, silk, nylon, and polyester in sizes 4‐0 to 0 USP and up to 120 cm long.
A significant advance in the Endo Stitch was the development of V‐Loc suture reloads for use with the device (Figure 2.27). Barbed sutured simplifies intracorporeal suturing by eliminating traditional knot tying and making it easier to maintain suture tension between bites. The use of a barbed suture was shown to decrease suturing time an additional 35–42% when compared to standard knot tying with the EndoStitch [25]. V‐Loc reloads are supplied as glycolide‐trimethylene carbonate (V‐Loc 180), which are absorbable and have an absorption profile similar to polyglyconate suture, or polybutester (V‐Loc PBT) which is nonabsorbable.
Several other ASDs exist, with a number of technical advancements made as more experience with ASDs has been gained. The RD‐180 (LSI Solutions, Victor, NY) is similar to the Endo Stitch and is used in concert with the Ti‐Knot Device (LSI Solutions, Victor, NY) and fastener to achieve adequate knot security. The RD‐180/Ti‐Knot device was found to be comparable to the Endo Stitch in surgical time and dehiscence rate when used for closure of the vaginal cuff during laparoscopic hysterectomy in women [26]. This device has not yet been described in the veterinary literature.
Further advancement in ASDs came with the development of roticulating devices. Roticulating devices offer the advantage of increased dexterity when working space is limited and multiple instruments may be in close proximity to the telescope. The SILS (single incision laparoscopic surgery) Stitch (Covidien, Mansfield, MA; Figure 2.28) is essentially a roticulating version of the EndoStitch for use with the SILS system, which is described elsewhere in this textbook. The SILS Stitch has successfully been used with barbed suture for laparoscopic gastropexy in dogs [27, 28]. When the SILS Stitch was compared to conventional intracorporeal sutured laparoscopic gastropexy using barbed suture, there was no difference in surgical time [28], suggesting that the added dexterity of the SILS Stitch may not necessarily translate into shorter surgical time. Other roticulating ASDs include the Proxisure (Ethicon, Summerville, NJ) and the Endo360 (Endoevolution, Raynham, MA), which use a curved needle in lieu of a straight needle. A curved needle may create less tissue trauma than a straight needle during needle passage. The most advanced innovation in ASDs has been the development of the Endosew (Karl Storz, Tuttlingen, Germany), which creates running sutures during robot‐assisted laparoscopic surgery [29, 30]. It has been used experimentally to create a U‐shaped ileal neobladder in a porcine model [30], but its use in veterinary medicine has not yet been reported.
Figure 2.26 Automated suturing devices. Small and standard endo stitch devices (bottom and center) and SILS (single incision laparoscopic surgery) Stitch (top). Both devices use monofilament and braided sutures as well as barbed sutures available on specially designed loading units.
Figure 2.27 V‐Loc 180 automated suture loading unit, 7 in. length with a terminal welded loop. Shorter suture lengths facilitate ligation and limited suturing.
Source: Copyright © 2013 Covidien. All rights reserved. Used with the permission of Covidien.
Figure 2.28 SILS (single incision laparoscopic surgery) Stitch automated suture device loaded with 7 in. V‐Loc 180 reload. The SILS Stitch device allows angular articulation of the distal 5 cm of the instrument, which affords greater versatility in suture needle placement.
Source: Copyright © 2013 Covidien. All rights reserved. Used with the permission of Covidien.
Using the Endo Stitch
