Ch 110 - Vagina, Vestibule and Vulva

Question 1

What embryological structure forms the cranial vagina?

Answer 1

Fusion of the paired paramesonephric (Mullerian) ducts

Question 2

What kind of epithelium does the vagina have?

Answer 2

Nonglandular, stratified squamous epithelium

Question 3

What it the blood supply to the vagine, urethra, vestibule and vulva?

Answer 3

• Vagina, urethra and vestibule - Vaginal artery (arises from internal pudendal)
• Vulva - External pudendal artery

Question 4

What are the most common commensal organisms of the canine vagina?

Answer 4

• E.Coli
• B-haemolytic Strep
• Staph pseudintermedius
• Pasteurella multocida

Question 5

What sized endoscope can be used for vaginoscopy?

Answer 5

• Small dogs and cats 3-5kg - 2.7mm rigid cystoscope with 10Fr sheath
• Dogs over 10kg - 4mm scope with 19Fr sheath

Question 6

List the approaches to the vagina

Answer 6

• Episiotomy
• Ventral approach (pubic symphysiotomy/ectomy)
• Combined abdominal and perineal approach

Question 7

List the forms of congenital vestibulovaginal stenosis

Answer 7

• Focal hypoplasia
• Imperforate hymen
• Vertical septum (vagina septa)
• Double vagina

Question 8

What is the cause of vestibulovaginal stenosis?

Answer 8

Retained epithelial tissue at the point of fusion of the paired paramesonephric ducts in the sagittal plane (vertical spetum) or at the transverse junction of the paramesonephric ducts with the urogenital sinus (imporforate hymen)

Question 9

What clinical signs may be seen with vestibulovaginal stenosis?

Answer 9

• Difficultly or pain associated with breeding
• Recurrent vaginitis
• Hydrocolpos (fluid accumulation within the vagina)
• Recurrent UTIs

Question 10

List the surgical options for vestibulovaginal stenosis

Answer 10

Vertical septa:
- Endoscopic laser ablation (Nd:YAG, Ho:YAG, diode)
- Endoscopic scissors
- Episiotomy with resection of septum at dorsal and ventral attachment

Annular:
- Circumferential partial thickness resection of mucosa and submucosa
- T-shaped vaginoplasty (1/5 had good outcome…)
- Complete resection and anastomosis (decreased fertility)
- Complete vaginectomy (Caudal laparotomy with pelvis osteotomy or episiotomy)

Question 11

Define rectovaginal fistulas and anovulvar clefts

Answer 11

• Rectovaginal fistula: A connection between the rectum and vagina or vestibule, typically assoc with atresia ani
• Anovulvar cleft: Failure of fusion between the dorsal urogenital folds leaving a midline defect in the perineal skin that normally seperates the anus and dorsal vulva commisure

Question 12

What is the surgical treatment of an anovulvar cleft?

Answer 12

Inverted V perineoplasty

Question 13

What is the prognosis for treatment of a recessed vulva with episioplasty?

Answer 13

Resolution of UTI in 84-100%

Question 14

What is vaginal oedema?
What is the recommended Tx?

Answer 14

• Certain young, femal entire dogs develop a mass of oedematous tissue arising from the ventral floor of the vagina, just cranial to the urethral tubercle, under the influence of oestrogen in late proestrus and oestrus
• Will resolve with termination of oestrus however recurrence is high, OVH is recommended
• Resection of oesematous tissue can be performed if it has become traumatised or in breeding animals

Question 15

List potential causes of clitoral hypertrophy

Answer 15

• Spontanous idiopathic
• Exogenous androgens
• Intersex conditions

Question 16

What are the most common vaginal neoplasias?

Answer 16

• 73-85% leiomyoma (pedunculated, intraluminal)
• Lyomyosarcoma is most common malignant mass

Question 17

What is the surgical options for malignant vaginal tumours?
What is the prognosis?

Answer 17

• Vulvovaginectomy and perineal urethrostomy (If entire, also need to approach the abdomen for OVH)
• Survival time 9wk-10m