Page 241 - Manual of Equine Field Surgery

Rectovaginal Fistula Repair 237
positioned along the ventrolateral aspect of the
sphincter for retraction if self-retaining retractors
are not used (Figure 43-1). The fistula margin is
incised circumferentially (Figure 43-2), exposing
the submucosal tissue and incised edges of the
rectal and vaginal mucosae (Figure 43-3). Taking
large, closely spaced ( 6- to 8-mm) bites, the
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Figure 43-1 Dilation of the anal sphincter using
umbilical tape secured around the base of the tail and
ventrolateral positioning of towel clamps allows good
visualization of the rectovaginal fistula.
submucosa is apposed transversely with No. 1
absorbable suture using a simple interrupted
pattern. The submucosal sutures should be pre-
placed beginning in the lateral aspects of the
fistula and tightened after all sutures have been
preplaced. Care should be taken to avoid purchase
of the rectal and vaginal mucosa within these bites
(Figure 43-4). The rectal mucosa is then apposed
transversely with No. 0 absorbable suture using a
continuous horizontal mattress pattern (Figure
. 43-5). Closure of the vaginal mucosa is optional.
Schonfelder Technique
Fistulas up to 6 cm have been repaired with this
technique.2 As long as principles of flap develop-
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Figure 43-3 Exposure of fresh submucosal tissue
and incised edges of the rectal and vaginal mucosae.
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Figure 43-2 Circumferential inci-
sion of the fistula using an 80-degree
scalpel handle.