Tissue Handling

The Other Hand

The steady repetition of the bite cycle by the dominant hand gets all the attention in bypass surgery because it drives the needle and leaves an artful spiral of suture in its wake. Little attention is paid to the nondominant hand wielding the microforceps because its actions are variable and leave no trace. This other hand handles tissues, sets up bites, feeds the needle, and ensures its safe passage through all of the suturing steps and cycles. The nondominant hand follows the dominant hand like a dancer reacting to the movements of her partner. A bypass’s secret of success is the skillful and gentle tissue handling by the microforceps. Grasping, spreading, touching, and counter-resisting are essential for suturing, but these actions, if performed to excess, can damage the intima, attract platelets, and form a thrombus at the anastomosis. This chapter focuses on this ignored and unsung “other hand.”

Presentation and Counter-Pressure

The microforceps hand has two key jobs during the bite: to present arterial tissues to the needle, and to counter-resist during needle penetration. To present tissues properly, the microforceps brings the arterial wall in contact with the needle’s point, aligns the tissue plane perpendicular to the needle, tilts the wall for a cross-sectional view of the bite from entry to exit, and clears the opposite walls away from the needle path. To counter-resist properly, the microforceps applies counterpressure as the needle driver initiates the bite for crisp wall penetration. These two touches are the microforceps’ only tissue contacts during the entire bite; the rest are with the needle. And yet these touches establish the suturing’s precision, ease of the bites, and, most importantly, everted arterial edges in the suture line. Eversion folds the wall’s inside edges outward so that intimal surfaces appose in the suture line (Fig. 10.1). In contrast, inversion folds the wall’s outside edge inward, which brings exterior surfaces together in the suture line and exposes the bloodstream to medial and adventitial tissues. The end result of the microforceps’ actions is to craft these superior everted stitches.

Presentation Techniques

The microforceps presents arterial tissues to the needle with six different actions: grasp, straddle, spread, probe, tent, and evert (Table 10.1). Grasping is the way that microforceps are used intuitively, with one tip placed inside the artery, the other tip placed outside the artery, and the handles squeezed to grasp the wall with two points of contact with the tissues (Fig. 10.2). Grasping holds tissue tightly, but traumatizes the endothelium and should be avoided.

Straddling is similar to grasping, but without the squeeze. One tip of the microforceps is placed inside the artery and the other tip is placed outside the artery, but the microforceps remains open with only one tip contacting the wall (Fig. 10.3). The forceps straddles tissue and uses one tip to lift, move, or reposition the wall for the bite. In contrast to grasping, straddling exerts no squeezing force, is atraumatic, and is a good presentation technique.

Spreading is the best presentation technique. The tips are inserted inside the arterial lumen, the microforceps are spread slightly, and both tips are brought into contact with the wall (Fig. 10.4). A smooth plane of tissue is presented to the needle for the bite, and the microforceps can flatten or steepen the angle of presentation to meet the needle perpendicularly. The instrument is not squeezed, but open and atraumatic, with its handles aligned parallel to the needle and perpendicular to the needle driver. Spreading the tips inside the artery defines its lumen. The spreading technique is similar to the straddling technique, except that the microforceps is rotated 90 degrees about its long axis. With spreading, the line between the microforceps’ tips runs parallel to the suture line, whereas with straddling, this line between the forceps’ tips runs perpendicular to the suture line.

Fig. 10.1 (A) Eversion folds the wall’s inside edges outward so that intimal surfaces appose in the suture line. (B) Inversion folds the wall’s outside edge inward, which brings exterior surfaces together in the suture line and exposes the bloodstream to medial and adventitial tissues. The end result of the microforceps’ actions is to craft these superior everted stitches.

Probing is a variation of spreading with the microforceps squeezed shut and its two tips together as one. The closed microforceps acts like a probe with a single point of contact and can maneuver inside the artery to lift or counter-resist (Fig. 10.5). This presentation technique pushes rather than holds tissue, which gives the microforceps freedom to orient in many directions and present tissues from many different angles. Probing squeezes no tissue and is gentle, but usually reserved for when the spreading technique is too awkward.

Tenting is ideal for presenting the second wall to the needle for the second part of a double-penetration bite (Fig. 10.6). When the first part ends with the needle’s point inside the lumen, the microforceps then moves extraluminally to present the second wall. Both tips of microforceps lie outside of the artery, away from the endothelium, and can therefore grasp the adventitia safely. In addition, this second wall often folds inward and covers the needle inside the anastomotic lumen. Lifting the exterior wall “tents” the tissues upward, unfolds the second wall, and presents it to the needle. Although the microforceps squeezes tissues, contact is with the adventitia and not harmful to the endothelium. Tenting is the opposite of spreading, as it entails closed tips, squeezed tissue, and an extraluminal position, on the one hand, and open tips, no squeezed tissue, and intraluminal position, on the other. Just as spreading is the ideal presentation technique for that first bite through the first wall into the lumen, tenting is the ideal technique for that second bite through the second wall out of the lumen.

Fig. 10.2 Grasping is the natural action of the microforceps, with one tip inside the artery, the other tip outside the artery, and the handles squeezed to grasp the wall with two points of contact. Grasping traumatizes the endothelium and should be avoided.

Fig. 10.3 Straddling is similar to grasping, but without the squeeze. One tip is inside the artery and the other tip is outside the artery, but the microforceps remains open with only one tip contacting the wall. One tip is used to lift, move, or reposition the wall for the bite. Straddling exerts no squeezing force, is atraumatic, and is a good presentation technique.

Fig. 10.4 Spreading is the best presentation technique. Both tips are inserted inside the arterial lumen in contact with the wall, and the microforceps are spread slightly to present a smooth plane of tissue to the needle that can flatten or steepen to meet the needle perpendicularly. The instrument is not squeezed, but open and atraumatic, with its handles aligned parallel to the needle and perpendicular to the needle driver. Spreading the tips inside the artery defines its lumen.

Fig. 10.5 Probing is a variation of spreading with the two tips closed together as one and acting like a probe with a single point of contact that can maneuver inside the artery to lift or counter-resist. This presentation technique pushes rather than holds tissue, which gives the microforceps freedom to orient in many directions and present tissues from different angles. Probing is reserved for when spreading is awkward.

Everting combines the spreading technique with an everting lift to fold the wall outward (Fig. 10.7). When an artery faces downward in a deep corridor and the luminal view is limited, its wall must be everted to bring the wall perpendicular to the needle and visualize the needle’s trajectory into the lumen through the wall thickness. The axis of the vessel and the instrument are almost parallel and the tips of straight microforceps cannot lift this edge, but angled microforceps can. When this instrument’s tips are spread and lifted inside the artery, the wall everts nicely for the bite.