Page 26 - Manual of Equine Field Surgery

22 PRESURGICAL PREPARATION AND ASSESSMENT

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Figure 3-14 Previously repaired pastern laceration
Figure 3-13 Partial closure of subcutaneous tissue

over Penrose drain. Drain sutured in place (arrow) and showing evidence of skin necrosis secondary to ban-

exits the site distal to the incision or wound site to avoid dages applied over tension suture supports. Three

the primary incision line. horizontal mattress sutures had been placed with
polyethylene supports 2 weeks previously.

tubing, function by gravity or pressure differen-

tials (Figure 3-13). The ideal drain is inert, soft,

smooth, nonreactive, and radiopaque. The disad- associated with complications. 18 Relief incisions

vantages of drains include the potential introduc- away from the wound margins can sometimes

tion of bacteria or foreign bodies into the wound, decrease tension. The relief incisions may be

the care involved to maintain patency, and the closed after the primary incision is closed or left

potential irritation and resultant scar tissue and to heal by second intention.

adhesion formation that may occur as the result Tension suture patterns used to reduce the

of a foreign body reaction. Drains should be tension on the primary suture line are placed well

removed after 2 to 3 days, when infection is con- back from the wound margins so that the blood

trolled, or if they are not functioning effectively. supply is not compromised. Once the tension

Ideally, wound drainage is expected to change sutures are in place, the primary incision line is

from an exudate to a transudate, and the quantity sutured to appose the wound edges. Widely placed

is expected to gradually diminish to negligible vertical mattress sutures, with or without support

levels during the 2- to 3-day period. using buttons, gauze, or rubber or polyethylene

tubing, are effective in reducing tension on the

primary suture line. Other tension suture patterns

MANAGEMENT OF SKIN TENSION include horizontal mattress, far-near-near-far,

and far-far-near-near patterns. Tension sutures

Excess tension on a primary suture line is likely to with supports are used in regions tl1at cannot be

complicate healing via local ischemia, cutting out effectively bandaged ( e.g., upper body, neck),

of sutures, and wound disruption. Methods to whereas no supports are used under bandages or

decrease tension on the primary suture line casts, because pressure on the supports may cause

include undermining the surrounding skin, pro- tissue necrosis (Figure 3-14). Tension sutures are

viding relief incisions, and the use of tension removed iI1 4 to 10 days, depending on the

suture patterns. Although excessive undermining appearance of the wound. Staggered removal is

is deleterious, undermining up to 4 cm from the preferred, removing half of the sutures initially

wound edge 011 distal limb wounds has not been and the remaining half later.