Ligation After Ovariohysterectomy: What Is Best?

Hemorrhage is a common complication of canine ovariohysterectomy. Pedicle ligation is performed to achieve vessel occlusion; success depends on suture material, ligation technique, number of ligatures, and preligation manipulation of the pedicle. This in vitro study investigated the difference in ligature strength in an ovarian pedicle vascular model. Using size USP 0 monofilament polyglyconate and braided multifilament polyglactin 910, 5 knots were compared: single square knot, single surgeon’s knot, single slip knot, modified transfixing knot, and single-double other side (SDOS) knot.

The first 3 knots were characterized by an encircling ligature tied to 1 side of the pedicle, while the modified transfixing and SDOS ligatures were tied on both sides of the pedicle. Although the square knot is recommended for vessel ligation, the modified transfixing ligature, slip knot, and SDOS knot outperformed it. The square knot may have performed poorly because of the bulk and characteristics of the polyester material used in the vascular model; the security of this ligature requires no slippage between the first and second throw. Slippage can occur if there is more expansive force (from bulk) than frictional force of the first throw. The monofilament outperformed the braided polyglactin 910 material, possibly because coating applied to many multifilament suture threads reduces tissue drag.

CommentaryAnecdotally, knots that encircle the pedicle twice or incorporate a knot on each side of the pedicle are superior to a simple square ligature when fat obscures the pedicle. In high volume spay/neuter clinics located in remote areas, a form of the Miller’s knot is common, as ovariohysterectomy candidates are often mature, overweight, pregnant, and/or have uterine disease. Although this study did not involve live animals, the findings supported the use of bilateral ligature techniques, and these options should be considered in private practice, especially for a larger patient.— Heather Troyer, DVM, DABVP, CVA

SourcePedicle ligation in ovariohysterectomy: An in vitro study of ligation techniques. Leitch BJ, Bray JP, Kim NJG, et al. J SMALL ANIM PRACT 53:592-598, 2012.