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Wound breakdown or infection: Ensure good aseptic technique, correct surgical technique (including suture selection and placement), and do not give antibiotics to routine neutering patients as these are clean surgeries and doing so can increase the risk of wound infection (including multidrug resistant wound infections). Discuss rest and avoiding self-trauma to wound with owners and use a buster collar as required. If you do get a wound infection, you will need to prescribe a course of antibiotics (ideally based on C&S), use open wound management and perform secondary closure if the wound is large once you have a healthy bed of granulation tissue. Haemorrhage: Usually poor ligature placement on ovarian or uterine arteries and/or failure to ligate large vessels in the broad ligament. More likely to occur with inadequate abdominal exposure. Ligate the uterine arteries individually as well as placing an encircling ligature around the cervix and ligate the broad ligament in mature or fat bitches. If haemorrhage is serious/deteriorating (ie. animal is in shock), re-explore the abdomen (stabilise shock first), make a large incision, use retractors and use the duodenal and colonic manoevres to locate and check the ovarian pedicles. Intermittent vaginal bleeding: This is due to erosion around uterine vessels underneath a ligature or infection of the ligature. Avoid a single ligature around uterine body ligate uterine arteries individually. If severe then perform exploratory laparotomy to re-resect uterine stump with ligation of individual uterine vessels and transfixing ligature of cervix. Ovarian remnant syndrome: This is due to failure to remove all ovarian tissue due to incorrect surgical technique. More likely to occur with inadequate abdominal exposure and more common in cats. Animal will show clinical signs of oestrus cycling and vaginal cytology at this time will be consistent with oestrus. Resolved by exploratory laparotomy and removal of ovarian tissue which is often (up to 50%) bilateral! Uterine stump pyometra: As for ovarian remnant syndrome with additional incomplete resection of uterine tissue, or incomplete resection of uterine tissue combined with exogenous source of progesterone. The uterine stump is re-resected as well as remnant ovarian tissue. Uterine stump granuloma: Caused by use of non absorbable sutures or other inappropriate sutures to ligate uterus, poor aseptic technique or excessive devitalised uterine tissue and can result in urinary incontinence. Requires exploratory laparotomy to resect affected tissue be careful of proximity and adhesions to bladder neck and ureters! Ligation of ureter: More likely to occur with inadequate abdominal exposure (and it is always a good idea to ensure the bladder is not full and expressing it manually if necessary whilst preparing the patient for surgery). Check carefully all the way around any ligature that you have not inadvertently included extra tissue before tying it down if you cant see all the way around the ligature then you need to improve your exposure!
Ureter ligation or trauma is most likely to occur when i) dealing with a dropped ovarian pedicle or ii) when ligating the cervix next to a distended bladder which is obscuring surgical visualisation and cranially displacing the trigone region. Ureteral obstruction hydronephrosis endstage kidney. Less commonly, inclusion of a ureter in a uterine ligature leads to erosion of the ureter and formation an acquired ureterovaginal fistula incontinence. Treatment of a ligated ureter is exploratory laparotomy and removal of ligature +/- re- implantation of the ureter (if less than 4 weeks) or ureteronephrectomy if end stage kidney. USMI: Overall, urinary incontinence is uncommon after OHE in bitches, @4-10%. The question of whether to spay before or after the first season is still controversial. Waiting to neuter until after the first season in at risk breeds e.g. Doberman, Old English Sheepdog, Weimaraner, Irish setter, Boxer or any other patient that already has urinary incontinence for whatever reason is advisable (50% of bitches with congenital (as apposed to acquired) USMI have resolution of incontinence after their first season. Resolve any obesity (urinary incontinence after spaying is more likely in heavier dogs) and decide on the merits of the various medical and surgical management options of for USMI. It is important to have mentioned this potential complication to owners prior to surgery, especially in at risk breeds. Note: Despite owners concern over this, OHE does NOT cause obesity. Q. How big should my incision be? A. The length of the incision is dependent on the size of the dog and should be made from cranial to the umbilicus and extended approximately 1/3 or greater of the distance to the pubis from the umbilicus. In cats, a midline incision should be positioned more caudally (middle third of the distance from the umbilicus to the pubis). See exploratory laparotomy lecture for tips on how to enter the abdominal cavity. A larger incision (if you perform a continuous suture pattern for closure) does not add significant surgical time and does not increase wound healing time at all. Q. How can I find the ovarian pedicle amongst all this fat? A. Two simple steps: 1. Make a bigger hole (+/- remove falciform fat) and use retractors. 2. Perform a duodenal manoeuvre for the right pedicle and a colonic manoeuvre for the left pedicle. Q. Could you please stop the bleeding? A. No problem: 1. Predict before the procedure which cases are going to potentially provide an increased surgical challenge, for example: obese animals (harder to identify and ligate pedicles) deep chested dogs (harder to elevate pedicles)
mature bitches that have had more than one oestrus (more likely to bleed from the broad ligament). For these dogs make a larger abdominal incision than usual from the outset and use abdominal retractors. This will allow you to fully expose the ovarian pedicles and hence allow easier access for your clamps and ligature placement. 2. If you encounter any problems during surgery in any patient, increase the exposure by making a bigger incision and using retractors. 3. Breakdown the suspensory ligament to ensure good exposure 4. Use the three clamp technique. 5. Consider a transfixing ligature for large ovarian pedicles. Use a sliding vascular knot to achieve a secure ligature when not performing transfixing ligatures. When applied correctly, a vascular knot is more secure than a surgeons (double throw) knot. 6. As you blunt dissect the broad ligament place haemostats on bleeding vessels and ligate if required. 7. Ligate the uterine artery on each side of the cervix before clamping / transecting and placing a transfixing ligature. 8. Consider doing an ovariectomy instead of an ovariohysterectomy. 9. Perform the duodenal and colonic manoevres to locate and check the ovarian pedicles. 10. If you are getting really stressed, take time out it is better to do nothing for a while than to blindly fish. Pack everything with swabs for a few minutes. Reposition your lights. Take a few deep breaths. Start again by improving your exposure using all the tips described above and if you can, ask nurse to scrub in. An animal will not bleed to death from an ovarian pedicle at a rapid rate. It will take less time to enlarge the incision, place retractors and ask someone to scrub in than to try to find a pedicle by blindly fishing. Blind fishing is also the way that really serious complications occur involving damage to important adjacent structures e.g. ureters. 11. Dont panic if your pedicle bleeds after ligature placement, just place another using all the tips described above. Place the second ligature directly over the top of the first ligature.
Q. How do I know it is not bleeding excessively? A. In the majority of cases, if you have a bleeding ovarian pedicle that requires attention, the blood will visibly well up from the abdominal cavity. Blood stains on a swab placed in the abdomen at the end of the procedure are not indicative of haemorrhage that needs attention. Perform the duodenal and colonic manoevres to visualize the ovarian pedicles directly before closure. Elevate bladder to check the uterine pedicle. Use suction or swabs
to remove blood around the ovarian pedicles and then it will be perfectly obvious if there is blood spurting out in a pulsatile rhythm from the pedicle it not a slow ooze that you have to wait for, if a ligature is too loose you will see haemorrhage pumping from the ovarian artery. Q. What is the risk of a stump pyometra occurring? A. Extremely low. For a stump pyometra to occur you have to leave remnants of both the uterus
and ovaries. It is more common in Europe to perform ovariectomy rather than ovariohysterectomy for sterilization of bitches. Practices in the UK are starting to offer clients the choice between these two procedures. The obvious benefit of ovariectomy for you as the surgeon is being able to position the incision cranial over the ovaries. In the cat the same applies. As a consequence you do not need
to be concerned if you do not remove the entire uterus, provided that you have removed both ovaries. Q. Which suture material should I use for ligation? A. Any of the modern synthetic absorbable sutures would be acceptable, although I probably wouldnt choose one of the very short lasting ones (e.g. Monocryl, Caprosyn). A multifilament (e.g. Vicryl, Dexon, Polysorb) is preferred by most surgeons for ligature use because of low memory/easy handling properties. Catgut can be used for ligatures but it loses knot security when it gets wet (it swells) so you need a minimum of four throws on the knot and promotes inflammation in the tissues around it. As a rule of thumb I put 4 throws on all ligatures regardless of the suture. Q. Cat spay flank versus midline approach? A. There is no reported difference in duration of surgery or complication rate in flank versus midline OHE in cats (Coe RJ et al 2006). However, one study found there was a tendency for cats spayed by a flank approach to be in more pain postoperatively (Burrow et al 2006). If the cat is pregnant or you have any other reason to believe the surgery may be more challenging a midline approach is preferable. It is much easier to extend a midline incision than a flank incision if a problem arises. Retractors are also helpful in cats, and if you dont have a small abdominal retractor, Weitlanders or even a pair of Gelpis may be used. Q. Dog castration closed or open approach? A. Both are acceptable. I usually perform a closed castration because there is less postoperative swelling with this technique. Lower the ligated pedicle before releasing it because you need to check for haemorrhage after tension on the pedicle has been reduced. Make sure skin sutures are not too tight as this is a common cause of postoperative discomfort in this area. Q. The dog castration I performed earlier on today has collapsed due to suspected postoperative haemorrhage how do I deal with this? A. The testicular pedicles retract back through the inguinal canals into the abdomen once they have been released at the pre-scrotal castration site. Therefore: 1. Scrotal swelling does not correlate with postoperative testicular artery haemorrhage 2. Testicular artery haemorrhage post-castration presents as progressive abdominal distension and shock. A peritoneal tap confirms the abdominal fluid is blood.
3. If a dog has serious/deteriorating haemorrhage (animal is in shock) post-castration then exploratory laparotomy to identify and re-ligate the bleeding testicular pedicle is required (stabilise shock first).
Caesarian
Section
Q.
How
do
I
know
a
C-section
is
indicated?
A.
Perform
a
physical
exam
to
check
the
bitch
is
pregnant
and
to
look
for
any
signs
of
illness,
dehydration
and
toxicity.
Perform
a
vaginal
exam
to
look
for
a
retained
puppy,
vaginal
discharge
and
check
for
presence
of
Fergusons
reflex
(pressure
against
the
vagina
and
cervix
normally
simulates
strong
uterine
and
abdominal
contractions
during
labour).
Ultrasound
is
useful
to
check
the
number
of
foetuses
as
well
as
foetal
heart
rates
and
movements
(unviable
foetuses
are
an
obvious
cause
for
C-section).
1. Obstructive
dystocia:
-
Oversized,
malpositioned
or
maldeveloped
foetus
-
Small
pelvic
canal
or
pelvic
fracture/trauma
2. Uterine
inertia
-
Complete
primary
uterine
inertia
i.e.
no
second-stage
labour
(gestation
>
70days)
-
Incomplete
primary
uterine
inertia
(i.e.
second-stage
starts
but
uterine
contractions
fail
and
are,
or
become,
refractory
to
oxytocin:
If
the
bitch
is
healthy
and
there
is
no
evidence
of
obstructive
dystocia
administer
oxytocin
(2
units/kg
IM,
not
exceeding
20
units).
If
there
is
no
response
after
45
minutes
and
there
is
still
no
distress
another
oxytocin
dose
may
be
given.
If
there
is
still
no
response
after
45
minutes
further
medical
therapy
is
unlikely
to
be
helpful
and
a
C-section
is
indicated.
If
healthy
pups
are
born
within
30
minutes
of
oxytocin,
it
can
be
repeated
every
30
minutes
as
needed.
Hypoglycaemia
and
hypocalcaemia
is
rare
at
this
stage
but
should
be
checked
for
if
there
is
no
response
to
oxytocin.
-
Secondary
uterine
inertia
i.e.
uterine
muscles
become
exhausted
after
prolonged
contraction
against
obstruction
or
after
efforts
to
expel
large
litter.
This
form
is
unresponsive
to
oxytocin
and
there
is
a
lack
of
Ferguson
reflex.
C-section
is
indicated
if
there
has
been
more
than
30
minutes
of
strong
unproductive
straining,
more
than
2
hours
of
weak
straining,
or
more
than
4
hours
since
the
birth
of
the
last
pup.
3. Foetal
putrefaction
4. History
of
previous
dystocia/C-section
The
prognosis
for
both
dam
and
foetuses
is
good
if
surgery
is
performed
within
12
hours
of
the
onset
of
second
stage
labour.
Neonate
survival
rates
after
surgical
treatment
of
dystocia
have
been
reported
as
92%
at
birth,
with
80%
of
pups
still
alive
seven
days
after
surgery.
Tips
for
performing
C-Section
surgery:
Prepare
everything
that
you
need
for
surgery
and
puppy
rescuscitation
before
you
induce
anaesthesia
to
minimise
anaesthetic
time.
Q. Can I spay the bitch at the same time? A. Lactation and neonatal survival rates are not reported to be adversely affected by ovariohysterectomy compared to a conventional caesarean. If the owner requests concurrent spaying this can be done either before or after the hysterotomy - both have similar survivals for dam and neonates. En bloc ovariohysterectomy (ovarian and uterine pedicles isolated and clamped just prior to removal of the uterus with the foetuses) reduces surgical time which is useful in debilitated bitches or queens with dystocia, minimises abdominal contamination with uterine fluid and does not produce any problems associated with lactation. Disadvantages include the need for more nurses to resuscitate numerous neonates simultaneously and the quick time needed between clamping of the uterus to removal of neonates (30-60 seconds). Q. How do I open the uterus and remove the puppies? A. A ventral midline incision in the body is the best approach to the uterus. Milk the puppies out through the incision, rupture the amniotic sac, clamp and cut the umbilical cord and aseptically pass the puppy to an unscrubbed assistant. You do not need to remove the placenta if they are difficult to separate. Q. What closure should I use? A. Single or double layer closure, appositional or inverting using absorbable monofilament suture material. Give oxytocin if the uterus does not begin to involute or is bleeding excessively.
Clip as much as you can just prior to induction. Even when anaesthetised you may need to do some clipping in lateral recumbency because the weight of a gravid uterus when the bitch is put into dorsal recumbency may compress the diaphragm and/or vena cava and cause problems with respiration (reduced tidal volume) and blood pressure. Placing a folded up towel under the animal to elevate the cranial end may help relieve some of this pressure. Place an intravenous catheter and give crystalloid fluid therapy (10ml/kg/hr) to avoid hypotension and decreased foetal blood flow due to fluid loss and blood loss. Use the minimum amount (to effect as needed) of anaesthetic and all other drugs that depress the cardiovascular system. Drugs that depress the mother will also depress the foetuses. Use abdominal swabs to pack of the uterus from the rest of the abdominal cavity before performing the hysterotomy to minimise contamination from uterine fluids. An intradermal suture pattern, avoiding the need for skin sutures, is useful with respect to suckling puppies not having to negotiate skin sutures post-operatively. You may give intravenous prophylactic antibiotics as this is a clean-contaminated surgery. Postoperative antibiotics are not required unless an infection is present e.g. putrefaction of a dead puppy or other complicating factors. There is no actual evidence base to make decisions regarding non-steroidal anti- inflammatory drugs in lactating bitches after C-section (NSAID are contra-indicated in pregnant bitches and puppies < 6 weeks) but a single intravenous dose after surgery seems to have no obvious adverse affects on neonates (Mathews, KA 2008) Place the puppies with the bitch as soon as is practical.
References
and
further
reading
www.vets.tv/spay
-
1hr
spaying
video
on
BVA
website,
inc.
demonstration
of
vascular
knot
Burrow
R,
Batchelor
D
and
Cripps
P
2005:
Complications
observed
during
and
after
ovariohysterctomy
of
142
bitches
at
a
veterinary
teaching
hospital.
Vet
Rec
157,
829-833
Coe
RJ,
Grint
NJ,
Tivers
MS
et
al
2006:
Comparison
of
flank
and
midline
approaches
to
the
ovariohysterectomy
of
cats.
Vet
REc
159,
309-313
Burrow
R,
Wawra
G,
Pinchbeck
G
et
al
2006:
Prospective
evaluation
of
postoperative
pain
in
cats
undergoing
ovariohysterectomy
by
a
midline
or
flank
approach.
Vet
Rec
158,
657-661
Thrusfield
MV,
Muirhead
RH
and
Holt
PE
1998:
Acquired
urinary
incontinence
in
bitches:
its
incidence
and
relationship
to
neutering
practices.
J
Small
Animal
Practice
39,
559
Stocklin-Gautschi
NM,
Hassig
M,
Reichler
IM,
Hubler
M,
Arnold
S
2001:
The
relationship
of
urinary
incontinence
to
early
spaying
in
bitches.
J
Reprod
Fertil
Suppl.,
57:233-6.
Robbins
MA,
Mullen
HS.
En
bloc
ovariohysterectomy
as
a
treatment
for
dystocia
in
dogs
and
cats.
Vet
Surg.
1994
Jan-Feb;23(1):48-52.
Mathews, KA 2008: Pain management for the pregnant, lactating and neonatal to paediatric dog and cat VCNA(SA) 38(6), 1291-1308