Small Animal Laparoscopy and Thoracoscopy. Группа авторов

need to be passed through the cannula or the cannula site. If the needle size is larger than the cannula allows, it may have to be passed through the cannula site with the cannula temporarily removed (Figure 2.12). The cannula is removed from the site while the assistant blocks gas exit, usually by digitally obstructing the defect. The instrument is placed through the cannula, and when it is exiting through the cannula end, the needle is either backloaded or the suture is grasped 2 cm from the swaged end and introduced into the abdomen through the cannula site (Figure 2.12). The cannula through which the instrument is positioned is then immediately replaced in the site to minimize gas leakage.

If the needle size is compatible with cannula size, which usually requires a 10‐ to 12‐mm cannula, the easiest introduction for a right‐handed surgeon is to grasp the suture 2–3 cm from the swaged on end of the needle with the left instrument and pass it through the cannula. The suture is grasped with the needle tip pointing toward the left (Figure 2.13), and thus is ready to be grasped with the right hand instrument. If the needle position is not good, it can easily be corrected by applying gentle traction to the suture material (Figure 2.14). An alternative introduction is to backload the needle and introduce through the cannula, and when in the abdomen, reposition the needle as described by Brody at al. [14] (Figures 2.15 and 2.16 Video 2.1). The cannula valve may need to be released when introducing to avoid disrupting the needle position or damaging the valve.

      Needle Positioning

      For surgeons experienced in traditional open suturing, the challenge of obtaining correct needle positioning in the needle driver often becomes a surprise. In fact, it has been shown that for novice laparoscopic surgeons, needle grasping and positioning within the needle driver are the most difficult and time‐consuming laparoscopic tasks [6].

      In our experience, determining if an acceptable perpendicular position has been obtained is one of the major challenges. Novices often do not understand the magnitude of the needle displacement until suturing is attempted and found to be near impossible. Self‐righting needle drivers or 3D systems may be important aids, but we have found that most trainees will learn the cues for needle positioning reasonably fast. If using a standard 3/8 circle needle, one cue to correct perpendicular needle positioning is that the light source is reflected along the side of the needle (Figure 2.11).

When a perpendicular or near‐perpendicular needle position has been achieved, the suture bite is performed very similar to open surgery. Clockwise rotation of the instrument handle will allow tissue purchase within the arc of the needle.

Figure 2.13 Needle introduction through a cannula. (A). The suture is grasped with the left‐hand instrument (for the right‐handed surgeon) 2–3 cm from the swaged on end. The needle is then passed through the cannula. The cannula valve may need to be released when introducing to avoid disrupting the needle position. (B). When visible in the field, the right needle driver grasps the needle. The left instrument maintains grasp on the suture until needle position is as desired for the suture bite.

Figure 2.14 Needle position correction. (A). The needle is not perpendicular in the jaw of the needle driver. (B). The left‐hand instrument grasps the suture, and the right hand is releasing the ratchet to loosen up the grasp of the needle without letting go of it. Now the suture can be gently manipulated until the needle is in a more optimal position.

Figure 2.15 Needle introduction through a left‐sided cannula according to Brody et al. [11] (A). The needle is grasped with the left‐hand instrument backloaded (i.e., with the needle tip pointing in toward the shaft of the instrument). The convex part of the needle is positioned at 3 o'clock. (B). The instrument is rotated clockwise 90° so the convexity points toward 6 o'clock. (C). The right needle driver can grasp the needle, one‐third to half the distance from the swaged on end, and the place the suture bite. (D). The needle is well positioned for a right‐to‐left suture bite.

      Needle Dance

The “needle dance” is commonly used when a left instrument has inserted the needle by grasping the suture. In addition, the needle dance is needed every time the needle has to be repositioned intracorporeally. As the needle is visualized in the field, the convex part of the needle is allowed to lightly touch an organ surface, and the grasping instrument is “dancing the needle” by letting it pivot around the organ contact point until a position is reached where the needle driver can grasp the needle in a perpendicular position and be ready for a suture bite (Figure 2.17, Video 2.2). Doing the “dance” midair is seldom successful; the surface contact is usually needed to manipulate the needle. If no suitable surface is available in the clinical situation, the alternative needle positioning method is called for.

      Techniques for Knot Tying: Simple Interrupted Sutures

      Similar to open surgery, many knot‐tying techniques are available in laparoscopic suturing. Here we will provide detailed instructions for two alternative techniques used in the VALS curriculum to successfully train a great number of novices.

Figure 2.16 Needle introduction through a right‐sided cannula according to Brody et al. [11](A). The needle is backloaded on the right‐hand instrument (i.e., with the needle tip pointing in toward the shaft of the instrument) and introduced with the convexity to the left at 9 o'clock. (B). Needle visible in the field at the 9 o'clock position. (C). The right instrument is rotated clockwise 90° so the needle convexity now points to 12 o'clock. (D). The left instrument is grasping the needle. (F). The left instrument has grasped the needle with the convexity still 12 o'clock. (F). The left instrument is rotated counterclockwise 180° so the convexity points to 6 o'clock. This technique preferably is used with a needle driver in the right hand and a grasping forceps in the left, as the grasping forceps rotate around the instrument axis, making the 180° turn more ergonomic. (G). The needle can now be grasped at the appropriate position. (H). The needle is positioned for a right‐to‐left suture bite.