Suturing and stapling in elective procedures


Suturing and stapling in elective procedures

Routine elective procedures, including ovariohysterectomy, castration, dewclaw removal and feline declaws, are the most common procedures in veterinary medicine. Because of their routine nature, it is easy to put little thought into the materials and methods used for ligation of transected vessels and closure of the wounds. While these procedures are straightforward, overall complication rates have been reported of 1 to 24 percent, with severe complication rates of 1 to 4 percent. Contemporary suture and wound closure manufacturers currently provide the practicing veterinarian with an ample armamentarium to provide safe and reliable wound closure. Critical evaluation of the materials and methods used in the procedure can be beneficial in reducing complications.

In addition to medical factors, economic factors will affect the choice of suture material, patterns and the use of stapling equipment. The cost of the material and equipment must be considered and viewed in light of savings in time and patient morbidity.

Use of vascular clips in general surgery Ovarian pedicle hemostasis can be achieved through the use of suture or stapling devices. Factors influencing the choice of materials used for hemostasis include the size of the patient, the amount of perivascular fat in the pedicle, the friability of the pedicle, the stage in the heat cycle, security of the hemostatic method, cost of the materials, ease of application and individual preference. There are a large number of methods and materials which can be considered. Some of the details and benefits of each will be discussed.

The most common methods of hemostasis of the ovarian pedicle involve one or more ligatures. The choice of ligature pattern depends heavily on the size and friability of the stump. A single encircling ligature is appropriate for small ovarian pedicles without much perivascular fat. Most surgeons will choose to place a second ligature for increased security. In larger pedicles, a transfixing ligature or Miller's knot is often used.

Suture material chosen for ovarian pedicle hemostasis should be strong, allow good tightness of the ligature to be achieved, and provide good knot security. Generally absorbable suture materials are chosen, however non-absorbable suture material can also be used. Given the affordability, strength and good handling characteristics of modern monofilament absorbable sutures make them a good choice for pedicle ligation. It is important to tie square knots, use five to six throws and leave 5 mm tails.

Figure 1: A stainless steel vascular clip is used to ligate smaller ovarian pedicles like those in dogs and cats.
A simple stainless steel vascular clip can be used to ligate smaller ovarian pedicles, like those in cats and small dogs (Figure 1, p. 10). It is helpful to use a vascular clip that closes first at the tip to avoid slippage of the ligated material. This device is best used on ovarian pedicles in small dogs, ferrets, rabbits, reptiles and cats. The tissue to be ligated must fit comfortably in the jaw of the instrument and one should avoid the temptation to include more tissue. Vascular clips are also useful in splenectomy, amputation and ligation of the short gastric vessels, but can be useful in ligating any small vessel. The vascular clips are intended to be left permanently in place.

The devices can be resterilized by ethylene oxide or Sterrad®. These devices apply a single vascular clip of approximately 7 mm in length. Their primary advantage is the speed and ease of application. The ovarian pedicle can be double ligated in a matter of seconds.

Larger ovarian pedicles are too wide for a single vascular clip. These pedicles can be ligated using a synthetic monofilament or braided absorbable suture.

Uterine stump This structure can present problems as it may be very large and friable in an older animal. In some cases, the use of a circumferential ligature is not appropriate. I recommend using an absorbable monofilament transfixing ligature for the uterine artery and vein. The actual stump can be oversewn using a single continuous suture pattern, a horizontal mattress or a conventional Parker-Kerr closure. It is important to securely close the uterine lumen.

Table 1.
Spermatic cord ligation I recommend using an open castration method so that the blood vessels are ligated separately from the tunica. In some cases, we have observed significant post-operative hemorrhage due to retraction of the spermatic vasculature. One can safely use an absorbable monofilament suture or a vascular clip. I recommend the use of double ligatures or vascular clips on each testicular artery and vein.

Body wall closure Secure and safe closure of every abdominal incision is paramount. We routinely use a simple continuous suture of an appropriately sized absorbable monofilament. When using a simple continuous method of closure, one should begin and end with simple square knots with two to three extra throws. In general, when using sutures for ligation or closure, it is important to use proper square knots, use five to six throws on each knot and at least 5-7 mm tails. It has been shown that continuous incorporation of the peritoneum with the body wall is not necessary; however, I prefer incorporating the peritoneum whenever possible. Continuous closure of the peritoneum is more important in cases with impaired wound healing or an abdominal transudate or exudate.