Spay Flashcards
why spay
§Population control (prevents pregnancy)
§No heats / heat behaviour
§ Prophylactic
> Pyometra
> Mammary tumours
> Uterine / ovarian tumours (eliminates risk if there are no sex hormones)
ovarian pedicle contains what
ovarian artery (from aorta), ovarian vein (to vena cava on right or renal vein on left), contained within fat
=> vascular pedicle
where to make OVH incision
§ Identify the umbilicus and visually divide the caudal abdomen into thirds
§ Dogs: incise from or just caudal to the umbilicus (cranial 1/3) > ovaries are more difficult to reach
§ Cats: incise along the middle 1/3
> uterine body is more difficult to reach
§ Start with a smaller incision and extend in required direction § Ventral midline approach through the linea alba
how to use spay hook
1.Start on the left side (easier) or the right (because there’s no spleen)
2. Lift the body wall on the side you wish to retrieve with thumb forceps (non dominant hand) to flatten the lateral body wall
> Ensure the spleen is not in your way (if so, move it over using fingers not instruments)
> Break down any ligamentous adhesions to the abdominal wall that will prevent your hook from passing down properly (especially in cats)
- Insert the hook (dominant hand) facing the wall or cranially and slide as deep as possible along the body wall
> Midway to caudal along your incision in a dog
> Cranial to midway along your incision in a cat - Turn the hook 180 degrees so it faces the abdominal cavity (turn in a caudal direction to avoid catching splenic vessels as you do this)
- Ensure your hook is straightened (perpendicular to the table / patient) and gently lift out
- If you feel resistance, stop (splenic ligament, ovary, retroperitoneal fat?)
- Be gentle and patient
- Examine the tissues carefully – the broad ligament is what you expect to catch and it might not look like the right structure at first glance! Catching the horn is also possible. Other times you will catch omentum, intestines and have to start again…
OVH step by step
- Break down suspensory ligament
- Make a window in the broad ligament just caudal to pedicle
- Apply clamps (dog)
- Apply pedicle ligatures
Ø 2 circumferential (cat)
Ø 1 circumferential, THEN 1 transfix (dog) - Cut pedicle, observe for bleeding, release and repeat
- Ligate or break down broad ligament bilaterally
- Ligate uterine body / uterine arteries
- Cut uterine body, observe for bleeding, release and remove
where and when to apply circumfrential vs transfixing ligatures in the dog
-circumferential first, closest to the patient
-transfixing above, closest to the ovary
purpose of clamping pedicle
Clamps are used to crush fat and make the vascular pedicle more amenable to ligation
typically do not clamp pedicle in:
> Cats - if minimal fat in ovarian pedicles
Uterine body of cats (always friable) or dogs that are /were recently in heat
how do break suspensory ligament
§ Start with a clamp (single click) on the proper ligament (white band between ovary and uterus)
§ Using the clamp apply gentle caudal and ventral tension until the suspensory ligament is taut (but the vessels /pedicle remain loose)
§ Identify suspensory ligament by palpation or visually
> Stretch / break with finger (be patient)
> Break using two mosquito forceps
> Cut with scissors
best type of clamps to apply to pedicle
Apply 2 or 3 clamps (Carmalts are ideal to prevent rupture and slippage of the pedicle) but may be too large for small patients (use a Crile or mosquito in small patients)
§Clamps are not always necessary like in very small patients with little fat in their pedicles!
what type of suture to use to ligate pedicle
§Absorbable suture
§Suture size depends on thickness (fat content) of the pedicle
§ 2-0 or 3-0 typically (as little as 4-0)
§0 only in very large dogs with fatty pedicles
> Larger suture is harder to tie tightly
> Too small a suture might break when attempting to ligate a large fatty pedicle
ØIf there is no fat or a small pedicle (just vessels) - do not place a surgeon’s throw as it will prevent sufficient tightening of the suture (possibly leading to pedicle hemorrhage)
how to ligate pedicle using 3 clamp technique
Two ligatures:
1. Circumferential in the crush created by the clamp farthest from the ovary (most proximal / bottom clamp - C1)
> Surgeon’s throw on 1st throw (only) to allow
compression of fat (unless small pedicle)
> 4 additional throws (2 square knots)
- Transfixing (large dogs) or circumferential (small dogs and cats) suture between the first suture and the second most distal clamp (C2) (OR in crush of C2 (dogs) or directly on pedicle (cats))
> Might need to ‘flash’ Carmalt to tie suture tightly
> Never clamp below the bottom suture
> Use PDS or Monocryl for ligatures
> transfixing: Pass around and then place 4-5 additional throws - Transect between C2 and C3 (leave both sutures in the patient!) and examine for bleeding before releasing
> cut as close to C2 as possible, leaving a small cuff of ischemic tissue (~0.5cm) but enough to prevent suture slippage
beware of including what structure in your ligatures
§Beware of including the omentum within your ligatures
§This is much more likely on the right side
§This can lead to loosening of the ligatures should the omentum slip out of the ligatures
how to break broad ligament
§Either tear the ligament with fingers or between two Carmalts (small patients with a thin and non- vascular broad ligament)
Or
§Ligate the broad ligament
> Typically clamp and circumferential or transfixing in the crush of the clamp
> You can double ligate but ligating the ‘patient’ side is sufficient as the other is coming out!
–
§ This is done after ligating and transecting each of the ovarian pedicles but before ligating the uterine body (and it helps release the uterine body for ligation)
§Identify & preserve the uterine vessels
> May run very close or ~1cm lateral to the uterine body within the broad lig
> Do not include the uterine vessels in the broad ligament ligation (or tearing)
where and how do we ligate the uterus, generally
§Ligate the uterine body just cranial to the cervix (i.e. leave the cervix in the animal)
§Not recommended to clamp feline uterus or uterus of dog recently in heat (friable) until transfixing ligatures on vessels
> Transfixing on vessel placed first with no previous crushing
> Keep your tension on your first throw for 3 to 4 seconds to create the crushing your clamp did not do, then tie your second throw
how to ligate uterus for a (large) dog
§ Place separate transfixing sutures around each uterine
vessel
§ Place a circumferential or transfixing ligature just distal to the uterine vessel sutures in the crush of a clamp (if clamped) - no more than 0.5 cm apart
UTERINE STUMP LIGATURE OPTIONS
