Page 239 - Clinical Manual of Small Animal Endosurgery

Female Reproductive Tract 227

Fig. 7.20 Vaginal foreign body (stick).

USMI
USMI is a common problem in spayed bitches, particularly those with a
short urethra and intrapelvic bladder. Many cases respond adequately
to medical therapy with phenylpropanolamine or diethyl stilboestrol;
however, some cases are refractory to treatment. Surgical correction may
be attempted but success rates are often disappointing. Surgery is also
rather invasive (although colposuspension can be carried out laparo-
scopically to minimise the trauma and postoperative discomfort).
An alternative treatment is to use an injection of a bulking agent at
three equidistant points submucosally in the proximal urethra to par-
tially occlude the lumen and act as a more effective ‘valve’. Several
bulking agents have been used, such as silicone, collagen and acellular
matrix (Acell™). This does not provide a permanent solution but can
provide a good control of continence for 12–18 months in almost 70%
of cases (Barth et al., 2005). The procedure can be repeated as necessary.
However, not all cases are suitable. In bitches with a very short and very
wide-diameter urethra it may prove difficult to provide an adequate
occlusion of the lumen and the effects are likely to be much shorter.
Urethral diameter varies considerably between individuals, even those of
the same size and breed, and careful case selection is vital.
To perform peri-urethral injection of collagen a 2.7 mm endoscope
in a cystoscopy sheath is advanced into the urethra as described above.
The bladder and urethra are examined for any ectopic ureters and the
tip of the cystoscope is withdrawn just inside the proximal urethra. A
23 gauge 25 cm needle is inserted into the instrument channel of the
cystoscope. If a sheathed needle is used, as supplied with some of the
collagen kits, it generally sits nicely in the centre of the instrument
channel. If an unsheathed needle is used it is helpful to place it through
a section of thin flexible tubing first. This can be cut to length so it just
fits the cystoscope channel. The tubing supplied for transendoscopic