Ovariohysterectomy Theory Flashcards
What is the most common surgical procedure?
Ovariohysterectomy
What is the purpose of an ovariohysterectomy?
- Surgical removal of the ovaries and uterus for the purpose of sterilisation
- Treatment of reproductive tract disease
Difference between
- ovariohysterectomy
- ovariectomy
Ovariohysterectomy: surgical removal of the uterus and ovaries
Ovariectomy: only the ovaries are removed. Skin and fascia incisions are considerably smaller and located more cranially with ovariectomy
Advantages of Laparoscopic procedures
Minimally invasive veterinary surgery maximising post operative patient comfort
- superior visualization
- use of vessel-sealing technology
- smaller incisions
Ovariohysterectomy Indications (elective)
Desexing
Reduction of mammary neoplasia risk
Treatment of behavioural conditions
Treatment of medical conditions
Council registration (cheaper)
Ovariohysterectomy Indications (disease)
Pyometra
Metritis, subinvolution of placental sites
Uterine torsion
Uterine prolapse
Uterine rupture
Uterine neoplasia
Persistent pseudopregnancy
Standard age to desex females
About 6 months
- preferably before the first or second oestrus
(but for many years welfare organisations were desexing between 8-12 weeks of age)
Considerations when desexing young (8-12 weeks) - positive
Claimed decreased stress and operative time
Assurance animal is desexed when rehomed
Decreased maturation of external genitalia
Considerations when desexing young (8-12 weeks)- negative
Increased incidence of oestrogen responsive urinary incontinence
Anaesthetic risk
Increased risk of bony neoplasia in giant breeds
What is it more risky to complete an ovariohysterectomy when in season?
Uterus is more friable (easily crumbled)
Increased blood supply
Oestrogen (which is surging at the time) can have a detrimental effect on haemostatic mechanisms
Can be a difficult procedure - need to warn owner of increased risk
How long do you delay an ovariohysterectomy?
Delay for 4 weeks after the onset of pro-oestrus
After a litter, wait 3 weeks after weaning (to allow mammary tissue to involute/ return to normal size)
Is it easier to spay an early pregnant bitch or a bitch in season?
Early pregnant bitch
Risk of mammary neoplasia
0.5% if spayed before 1st oestrous
8% if spayed after the first oestrous
26% if spayed after the second oestrous
NO DECREASE if spayed after 4 oestrus cycles
Incidence of mammary tumours in entire cats
7 X the incidence
What suspends the uterus and ovary in the abdominal cavity?
Paired double folds of peritoneum
- the BROAD Ligaments
What are the 3 broad ligaments?
Mesovarium
Mesosalpinx
Mesometrium
What is the suspensory ligament?
The cranial continuation of the broad ligament from the ovary
- coalesces (comes together) into a distinct band
Where does the suspensory ligament insert?
On the middle and ventral thirds of the last 2 ribs
What does the proper ligament do?
Attaches the ovary to the uterine body
What attaches the ovary to the uterine body?
The proper ligament
What does the proper ligament become ?
Continues caudally as the round ligament
Where does the round ligament go?
Caudal continuation of the proper ligament
Courses within the broad ligament , passing through the inguinal canal and terminating subcutaneously near the vulva
What ligament courses through the broad ligament?
The round ligament (caudal continuation of the proper ligament)
What ligament terminates subcutaneously near the vulva
The round ligament (caudal continuation of the proper ligament)
What is the name of the ovarian blood supply?
Ovarian arteriovenous complex
Where does the ovarian arteriovenous lie?
Medial to the broad ligament
Caudal to the suspensory ligament
Shape of the ovarian arteriovenous
Convoluted especially closer to the ovary
What is the ovarian artery?
A direct branch off the aorta
Where does the right ovarian vein drain?
Into the caudal vena cava
What drains into the caudal vena cava ?
The right ovarian vein
Where does the left ovarian vein drain?
Into the left renal vein
What drains into the left renal vein?
The left ovarian vein
What supplies the ovary and cranial aspect of the uterus?
The ovarian artery
What does the ovarian artery do?
Supplies the ovary and cranial aspect of the uterus
What is the uterine artery ?
A branch of the internal pudendal artery
Where is the uterine artery positioned?
On the lateral aspect of the uterine bodies bilaterally
Where are anastomoses believed to exist?
Between ovarian and uterine arteries
Where does the uterine artery enter the mesometrium?
At the level of the cervix
Where do the lymphatics drain?
Drain to the hypogastric and lumbar lymph nodes
Innervation (sympathetic + visceral)
Hypogastric plexus
Innervation (parasympathetic + visceral)
Pelvic nerves
Is ventral midline or flank preferred?
Ventral midline
Advantages of ventral midline over flank (4)
Better access to peritoneal cavity if problems
Can check haemostasis
Access to right ovary can be difficult through flank approach
Anecdotally increased incidence of seroma (fluid build up) in flank approach due to 3 x muscle layers
Which approach is commonly performed in UK?
Flank
+ at some welfare centres and private practices
Which species has the more mobile cervix?
Canine
Which species ovaries are easier to expose
Feline
Location and size of canine incision
1-2cm caudal to umbilicus
extending 5cms
Location and size of feline incision
3-4 cm incision
centred over the midpoint between the cranial rim of the pelvis and umbilicus
Where are the uterine horns located?
Dorsolateral gutter of the abdomen
Where is the uterine body located?
Ventral to the rectum
Dorsal to the bladder
