Page 243 - Manual of Equine Field Surgery

Rectovaginal Fistula Repair 239

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Figure 43- 7 Transverse cross section of a vaginal

tissue flap rotated into position so that the vaginal ~ 0 ..,. ,&,
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mucosa is facing dorsally and its margins are at least Figure 43-8 Complete horizontal dissection

2 mm beyond the fistula margin. The flap is circum- between the ventral surface of the anal sphincter and

ferentially secured to the edges of the fistula using a dorsal commissure of the vulva extending through the

simple interrupted pattern.
fistula to create rectal and vaginal shelves. The dotted

lines indicate proposed areas of dissection.

vulva. Dissection is continued cranially in a hori-

zontal plane through the perineal body and rec- using a continuous horizontal mattress pattern.

tovaginal shelf, attempting to separate the fistula The vaginal mucosa is longitudinally or trans-

into two equal-thickness :fistulas (rectal and versely apposed with No. 0 absorbable suture

vaginal) (Figure 43-8). The rectal and vaginal using a continuous horizontal mattress pattern.

mucosae are circumferentially dissected approxi-

mately 2 to 3 cm from the underlying tissue sur- Huber Technique

rounding the fistula. Avoiding the rectal mucosa,

the rectal :fistula is transversely closed with No. 1 This technique is a combination of the Bemis and

absorbable suture using an interrupted Lembert conversion to third-degree laceration techniques

pattern. The sutures are preplaced beginning iI1 that can be used to repair large fistulas. Longi-
5'6

the lateral aspects of the fistula and tightened after tudinal division of the vaginal shelf provides

all have been preplaced. The vaginal :fistula is then excellent exposure and surgical access for suture

longitudinally closed with No. 1 absorbable suture placement. Healthy tension-absorbing rectal

using an interrupted Lembert pattern. The sutures tissues located between the fistula and perineum

are preplaced beginning in the rostral and caudal are preserved, and broad, generous shelves of

aspects of the :fistula and tightened after all have perirectal and perivaginal tissues are created.

been preplaced (Figure 43-9). After both :fistulas An 8- to 10-cm transverse perinea! incision is

have been closed, the remaining tissue surround- made equidistant from the ventral surface of the

ing and caudal to the fistulas is closed with No. 0 anal sphincter and the dorsal commissure of the

absorbable suture using a simple interrupted vulva. Dissection is continued cranially in a hori-

pattern. The transverse perinea! skin incision can zontal plane through the perineal body and rec-

be left to heal by second intention or primarily tovaginal shelf, attempting to separate the fistula

closed with No. 2-0 nonabsorbable suture using a into two equal-thickness fistulas (rectal and

simple interrupted pattern. The rectal mucosa is vaginal) (see Figure 43-8). The rectal and vaginal

transversely apposed with No. 0 absorbable suture mucosae are circumferentially dissected approxi-