Chapter 62 - Vulva, vestible, vagina and cervix Flashcards
(268 cards)
1
Q
name the vulvar abnoramlities:
A
- Pneumovagina
- caslick procedure - Innefective vestibular constrictor muscles
- perineal body reconstruction - Urovagina
- Pouret or perineal body transection
- caudal relocation of transverse fold (Monin)
- Caudal urethral extension with 3 tx:
I - Brown technique
II - Shires technique
III - Mckinnon technique
IV - Combined Brown and Mckinnon technique - Perineal lacerations (First, second, third degree)
4.1 - Two-stage repair
4.2 - Single stage repair - Rectovestibular Fistula
- horizontal approach through perineal body
- direct suturing technique - Cervical injury laceration
-Knowles cervical forceps
-stay sutures - Cervical adhesions
-sharp dissection - Cervical incompetence
- buried retention suture
8.Squamous cell carninoma of clitores
-sinusectomy - congenital anomalies (cervical aplasia, double cervic, congenital incompetent cervix)
- ovariohysterectomy - Vaginal varicosities
- ligation, cauterization, laser photocoagulation
2
Q
What are the primary structures of the caudal reproductive tract?
A
Vulva, vestibule, vagina, and cervix.
3
Q
What conformational abnormalities can predispose a mare to infertility?
A
Pneumovagina, urine pooling, cervicitis, and metritis.
4
Q
What two structures define the perineum?
A
The vulva and the base of the tail.
5
Q
What structures bound the perineum laterally?
A
Semimembranosus muscles and sacrosciatic ligaments.
6
Q
What is the typical length of the external orifice of the vulva?
A
12 to 15 cm.
7
Q
What forms the dorsal commissure of the vulva?
A
The labia meeting dorsally, located ventral to the anus.
8
Q
What forms the ventral commissure of the vulva?
A
The labia meeting caudal and ventral to the ischial arch.
9
Q
What fraction of the vulvar cleft should lie ventral to the ischial arch?
A
Approximately two-thirds.
10
Q
What degree of deviation from the horizontal plane is considered normal for vulva conformation?
A
Less than 10 degrees.
11
Q
What muscle lies deep to the skin of the vulva?
A
Constrictor vulvae muscle.
12
Q
Which vessels provide blood supply to the vulva, labia, and clitoris?
A
Internal pudendal vessels.
13
Q
What nerves innervate the muscles of the vestibule and vulva?
A
Pudendal and caudal rectal nerves.
14
Q
Where is the perineal body located?
A
Between the anus and vulva.
15
Q
What forms the perineal body?
A
External anal sphincter and constrictor vulvae muscles.
16
Q
What is the homologue of the penis in the mare?
A
The clitoris.
17
Q
Where is the clitoris located?
A
At the ventral commissure of the vulvar labia.
18
Q
What is the approximate diameter of the clitoral glans?
A
About 2.5 cm.
19
Q
What is the primary composition of the clitoral glans?
A
Erectile tissue, similar to the corpus cavernosum penis.
20
Q
What structure surrounds the glans of the clitoris?
A
Clitoral fossa
21
Q
How long is the body of the clitoris?
A
Approximately 5 cm.
22
Q
What does the body of the clitoris attach to?
A
The ischial arch by two crura.
23
Q
What is the vestibule, and where does it connect?
A
The terminal part of the genital tract, connecting the vulva to the vagina.
24
Q
What is the typical length of the vestibule?
A
12 to 15 cm.
25
What is the cranial extent of the vestibule marked by?
The transverse fold, located dorsal to the external urethral orifice.
26
What muscle covers the lateral and ventral surface of the vestibule?
Constrictor vestibuli muscle.
27
Where is the vestibular sphincter formed?
By the constrictor vestibuli muscles, hymen pillars, and pelvic floor.
28
What part of the reproductive tract does the vagina extend to?
From the transverse fold to the vaginal fornix around the cervix.
29
What structures are adjacent to the vagina dorsally and ventrally?
The rectum dorsally, the bladder and urethra ventrally.
30
How is the cranial part of the vagina covered?
Mostly retroperitoneally, with some peritoneal coverage based on rectal and bladder fullness.
31
What vessels supply blood to the vagina?
Internal pudendal vessels.
32
Why does the vagina lack motor innervation?
It has no skeletal muscle.
33
What type of ganglia are found in the vaginal wall?
Sympathetic ganglia.
34
What structure separates the caudal reproductive tract from the uterus?
The cervix.
35
Where is the external cervical os located?
In the cranial aspect (fornix) of the vagina.
36
What is the primary function of the cervix?
Acts as a sphincter, separating the caudal reproductive tract from the uterus.
37
What is the mucosal lining of the cervix characterized by?
Many longitudinal folds.
38
Name the three protective barriers in the caudal reproductive tract.
Constrictor vulvae muscles, vestibular sphincter, and cervix.
39
What consequence might result from the incompetency of these barriers?
Contamination of the reproductive tract, potentially leading to infertility.
40
What is the economic impact of infertility in mares?
Significant impact on the equine industry
41
Which muscle blends with the constrictor vulvae muscle caudally?
Constrictor vestibuli muscle.
42
What can cause failure of the protective barriers in the caudal reproductive tract?
Conformational abnormalities, trauma from breeding, or foaling.
43
Name three conformational abnormalities that predispose a mare to pneumovagina.
Flat croup, sunken anus, and underdeveloped vulvar labia.
44
In what type of mares is poor perineal conformation often found?
Older multiparous mares with thin body condition.
45
List two common types of injuries to the caudal reproductive tract that may occur during foaling.
Cervical lacerations and perineal lacerations.
46
What injury involves the creation of an abnormal opening between the rectum and the vestibule?
Rectovestibular fistula.
47
What complication may result from untreated trauma to the reproductive tract?
Infertility.
48
How does perforation of the vagina typically occur during breeding?
During intromission, especially if the stallion is large or overly vigorous.
49
What can develop if semen enters the peritoneal cavity during breeding?
Peritonitis.
50
What is the term for an accidental entry of the stallion's penis into the mare’s rectum?
Emperforation.
51
What external examination is essential for assessing potential reproductive tract issues?
Evaluation of perineal and vulvar conformation.
52
Why is the conformation of the vulva critical in the mare’s reproductive health?
It acts as the first line of defense against contamination.
53
What index is used to evaluate the risk of ascending infections in the reproductive tract?
Pascoe’s Caslick Index.
54
What value on the Caslick Index is associated with higher pregnancy rates?
Less than 150.
55
Name one internal examination technique for the reproductive tract of a mare.
Speculum examination.
56
Why are endometrial biopsy, culture, and cytology samples important?
To assess for infection or other reproductive health issues.
57
What type of drug is acetylpromazine, and what does it provide?
A tranquilizer, providing sedation without analgesia.
58
What two drugs are commonly used for sedative-hypnotic effects in horses?
Xylazine hydrochloride and detomidine hydrochloride. 0.04mg/kg
59
Why might reduced drug dosages be used for draft breeds?
They achieve desired effects at lower doses than lighter breeds.
60
How is epidural anesthesia achieved in mares?
By injecting anesthetic between the dura mater and periosteum.
61
What is the purpose of caudal epidural anesthesia?
To block sensory innervation without affecting motor control.
62
here is the typical injection site for caudal epidural anesthesia?
Sacrocaudal or first intercoccygeal vertebral space.
63
What technique is used to confirm epidural needle placement?
Hanging drop technique.
64
What complication may arise from multiple epidural injections?
Scar tissue formation over the intercoccygeal space.
65
What combination of drugs provides extended analgesia with mild ataxia?
Lidocaine (0.22 mg/kg) and xylazine (0.17 mg/kg).
66
What drug class does xylazine belong to and what does it provide in epidural use?
α2-adrenergic receptor agonist, providing profound analgesia.
67
Figure 62-1. Muscles of the perineal region. a, Retractor clitoridis; b,
external anal sphincter (cranial superficial part); c, levator ani; d, subanal
loop of levator ani; e, ventral part of levator ani; f, urethralis; g, external
anal sphincter (caudal superficial part); h, perineal septum; i, crus clitoridis
(cut); j, constrictor vestibuli; k, constrictor vulvae.
68
Figure 62-2. Drawing of a sagittal section of the muscles that are part
of the vulvar and vestibular sphincters and the perineal body. a, External
anal sphincter; b, internal anal sphincter; c, internal anal sphincter; d,
external anal sphincter; e, muscular fibers from external anal sphincter
to constrictor vulvae; f, cranial superficial part and deep part of external
anal sphincter; g, rectal musculature; h, rectovaginal septum; i, vaginal
musculature; j, vaginal musculature; k, rectal part of retractor clitoridis;
l, clitoral part of retractor clitoridis; m, subanal loop of levator ani; n,
decussation of retractor clitoridis; o, perineal septum; p, clitoral sinus; q,
glans clitoris; r, clitoral fossa.
69
Figure 62-3. Modified Finochietto retractor with long blades. This retractor is very useful for certain surgical procedures of the caudal reproductive tract, such as repair of a cervical laceration.
70
Figure 62-4. Long-handled surgical instruments.
71
Figure 62-5. Caslick procedure. (A) Removal of narrow strip of tissue from mucocutaneous junction. (B) Closure using Ford interlocking pattern.
72
What predisposes mares to pneumovagina?
Poor perineal conformation (old mares)
sunken anus,
flat croup,
thin body condition
udnerdeveloped labia
trauma from breeding or foaling
73
what techniques would you use for pneumovagina?
Caslick
Perineal body reconstruction (Gadd tx)
Perineal body transection
74
What are common injuries in the caudal reproductive tract from foaling?
Cervical lacerations, perineal lacerations, rectovestibular fistulas, and uterine prolapse.
75
What can happen if vaginal perforation occurs during breeding?
Peritonitis can develop if semen enters the peritoneal cavity.
76
What factors increase the risk of rectal injury during breeding?
Poor vulvar conformation, a small vulvar opening after Caslick procedure, and relaxed anal sphincter.
77
Why is it important to examine the conformation of the vulva in mares?
The vulva acts as the first line of defense against contamination of the reproductive tract.
78
What is the Pascoe’s Caslick Index used for?
To assess the risk of ascending infection based on vulvar length and angle
79
What does the presence of air rushing into the vagina upon labial separation indicate?
A predisposition to pneumovagina.
80
What clinical signs indicate urovagina?
Pooling of urine in the vagina, often accompanied by perineal conformation issues.
81
Why is the sacrocaudal vertebral space chosen for epidural anesthesia?
It blocks sensory innervation without impairing hind limb motor control.
82
What is the hanging drop technique in epidural anesthesia?
It confirms placement by observing fluid aspiration when in the epidural space.
83
What complications can arise from local anesthetic epidural injections?
Ataxia and possible recumbency due to motor and sensory blockade
**RISK VOLUME DEPENDENT**
84
What complication can arise from the Caslick procedure if the vulvar cleft is overly closed?
Caslicks is to correct pneumovagin but can result in **urovagina,** where urine pools in the vagina.
85
xylazine 0.17 mg/kg and lidocaine (0.22mg/kg) produces analgesia for how much time?
5 hours
86
What is the main purpose of a Caslick procedure?
To prevent pneumovagina by sealing the vulva and reducing air aspiration.
87
when do you perform episiotomy (remove Caslick)?
2 weeks before foaling
88
What is a breeding stitch, and when is it used?
A suture at the ventral limit of a Caslick to protect it during breeding, removed after pregnancy confirmation.
89
Balfour retractors are used in which anatomical zone surgery?
Difficulty passing a tube speculum and potential urovagina development (more deep)
90
Finochetto with long blades is for the repair of
cervical lesions
91
describe epidural anesthesia btw the 2 coccygeal vertebra
xylazine 5-7 mL of 2% solution per 500 kg body weight (0.17 mg/kg) - 60 to 90 min analgesia and xyla + lido (0.22mg/kg) = 5 hours
20 G 7.5 cm needle
Sacrocaudal or 1st intercoccygeal vertebral space
Co1-Co2 : Needle positioned just **cranial to the dorsal spinous process** of the second coccygeal vertebra. The needle is inserted through the skin at a **30-degree angle** relative to the skin and inserted craniad. The needle is advanced cranially until the hub is against the skin. If bone is encountered, the needle should be redirected. Once the needle is placed, the stylet should be withdrawn, and the hub of the needle is filled with the local anesthetic to be injected. If the needle is positioned in the epidural space, the fluid will be aspirated (hanging drop technique).
Minimal resistance is encountered during epidural injection.
92
The mare has a thicken skin and scar what other tx of epidural can you perform?
A second technique uses a **38-mm 18-gauge needle** that is positioned over the** first intercoccygeal space **with the bevel of the needle positioned **forward** and inserted at a **75-degree angle to the skin**. The needle is advanced and the hanging drop technique is utilized to confirm placement into the epidural space. Mares that have had previous epidural injections may develop fibrous scar tissue over the intercoccygeal space, making needle placement more difficult
93
How long does detomidine provide analgesia when used epidurally?
Approximately 2-3 hours dose 0.03 - 0.06 mg/kg
94
What muscle function is targeted in perineal body reconstruction (Gadd technique)?
The **constrictor vulvae** and **vestibular sphincter.**
Damage to the perineal body occurs from repeated stretching of these muscles in older multiparous mares, or from foaling trauma (second-degree rectovestibular injury).
95
What is the primary goal of perineal body reconstruction (Gadd tx)?
To restore vestibular sphincter function and proper vulvar orientation.
96
what other name has the perineal body reconstruction?
episioplasty or Gadd technique and perineal body reconstruction
97
Describe the first steps of reconstruction of perineal body reconstruction (Gadd tx)
Gadd technique involves closure of the dorsal vulva after two large triangular flaps of vestibular mucosa, which connect dorsally, have been removed
- The surgery is performed with the mare sedated and restrained in stocks.
- Epidural anesthesia or local infiltration is used to desensitize the surgery site.
- The labia are retracted to the side using towel clamps or stay sutures.
- An incision is made along the mucocutaneous junction of the labia in a dorsoventral direction and is extended craniad along the dorsal commissure of the vestibule to the level of the vestibulovaginal sphincter.
- Dissection is continued submucosally from the dorsum and dorsolateral aspects of the vestibule. The triangular tissue flaps of mucosa are dissected so that they approximate the shape of the perineal body. Using caudal dorsal retraction on the stay sutures, the desired position for closure of the tissues is chosen (Figure 62-7).
98
Describe the perineal reconstruction steps suturing
1. The vestibular mucosa is closed using USP size 2-0 or 0 absorbable suture material in a horizontal mattress pattern, inverting the mucosa into the vestibule.
2. The submucosal tissue is closed beginning at the cranial aspect of the vestibule using USP size 0 or 1 absorbable suture material in an interrupted pattern.
3. The labial skin is apposed as for the Caslick procedure.
99
What is the recommendation after perineal reconstruction?
4 weeks of sexual rest
Diameter of vestibule is decreased with this procedure episiotomy may be required at the time of foaling
100
Figure 62-8. Perineal body transection. (A) The dotted line shows the plane of dissection between the rectum and the caudal reproductive tract. (B) Dissection is performed craniad using a combination of blunt and sharp separation of tissues until the vulva assumes a more vertical orientation.
101
Why should anesthesia volume be limited in epidurals?
Excessive volume can cause ataxia by cranial migration of the anesthetic.
102
Figure 62-6. Breeding stitch placed ventral to a Caslick suture. (A) Large suture material or umbilical tape is placed in a simple interrupted pattern. (B) The suture is tied and the ends are cut short so that they do not contact the stallion’s penis during breeding.
103
Figure 62-7. Perineal body reconstruction. (A) The triangular piece of mucosa to be excised from the dorsal vestibule is outlined. (B) The dorsal portion of the vulva and vestibule are retracted caudad and the vestibular mucosa is closed. (C) Submucosal tissues are apposed with a series of interrupted absorbable sutures. (D) The labial skin is closed with interrupted sutures and the vulva is now oriented in a more vertical position.
104
what technique treats simultaneously pneumovagina and urovagina?
perineal body transection (Poure)
105
Who developed the perineal body transection technique?
Pouret.
106
What length incision is typically made for perineal body transection?
A 4-6 cm horizontal incision.
107
Where is the initial incision made in perineal body transection?
Midway between the ventral anus and dorsal commissure of the vulva.
108
How far does the dissection continue craniad in perineal body transection?
8 to 14 cm.
109
What is the purpose of placing a hand in the vestibule during dissection?
To guide the dissection and avoid entering the rectum or peritoneal cavity.
110
What anatomical change does perineal body transection achieve?
Repositions the vulva to a more vertical orientation.
111
What type of closure may be used after perineal body transection?
Transverse or T-shaped skin closure.
112
What is the alternative to skin closure in perineal body transection?
Allowing the wound to heal by second intention.
113
How long should natural breeding be delayed post-surgery?
Until healing, approximately 3 weeks.
114
Can mares be bred by artificial insemination immediately after perineal body transection surgery?
Yes, after proper healing of the wound.
115
describe in detail the perineal body transection
- Sedation and restrained in stock
- Epidural anesthesia or local infiltration
- 4- to 6-cm horizontal skin incision is made midway between the ventral aspect of the anus and the dorsal commissure of the vulva.
- This incision is continued ventrad for 3 to 4 cm on both sides of the vulva.
- A combination of blunt and sharp dissection is used to extend the dissection in a cranial direction through the muscles of the perineal body.
- The dissection is continued craniad for 8 to 14 cm until the connections between the rectum and caudal reproductive tract have been severed.
Placing a hand in the vestibule to help guide the dissection is useful to prevent inadvertent entry into the rectum or peritoneal cavity.
The dissection should be continued until the vulva has attained a normal vertical position without applying traction (Figure 62-8). No attempt is made to close the resulting dead space between the rectum and reproductive tract.
Closure of the skin, either transversely or in a T-shaped configuration, has been suggested
116
What is another term for urovagina?
Vesicovaginal reflux of urine which is accumulation or pooling of urine in the vaginal fornix
117
In which group of mares is urovagina most commonly seen?
Thin, multiparous mares.
118
How does perineal conformation contribute to urovagina?
Cranioventral sloping of the vagina causes urine to pool.
119
What visual anatomical change often accompanies urovagina?
A sunken anus and dorsal vulva.
120
How might a Caslick procedure contribute to urovagina?
Excessive closure can lead to urine reflux.
121
What complication may arise if urovagina goes untreated?
Chronic vaginitis, cervicitis, and endometritis.
122
How can urovagina affect fertility in mares?
It causes inflammatory conditions that hinder conception and pregnancy.
123
What diagnostic tool is used to confirm urovagina?
Vaginoscopy or speculum examination.
124
During which reproductive phase is urovagina best diagnosed?
**Estrus,** due to relaxation of reproductive tract tissues.
125
What is a differential diagnosis for fluid accumulation in the cranial vagina?
Uterine infection with exudate.
126
What test can help confirm the fluid in urovagina is urine?
Testing for creatinine and urea nitrogen levels.
127
Why are creatinine levels in urine pooled in the vagina elevated?
They are 2-3 times higher than serum creatinine levels.
128
What is a non-surgical management option for urovagina?
Manual evacuation of urine before breeding.
129
Name the surgical tx for urovagina
Monin technique
Brown technique
Shires technique
McKinnon technique
Combined Brown and McKinnon
130
What is the Monin technique used for?
Caudal translocation of the transverse urethral fold.
131
For which cases is the Monin technique best suited?
Minimal reflux and mild perineal conformation issues.
132
Why might the Monin technique complicate future surgeries?
It makes subsequent urethral extension procedures more difficult.
133
What tool is used to access the transverse fold in the Monin technique?
A Balfour retractor or stay sutures.
134
How is the transverse fold manipulated in the Monin technique?
The fold is split into dorsal and ventral shelves.
135
Describe Monin technique?
Balfour retractors * Grasp center of transverse fold with Allis tissue forceps and retract caudally
* Slice fold horizontally splitting into dorsal and ventral shelves
* Ventral shelf positioned along ventrolateral vestibular walls
* Mucosal incisions made in vestibular walls at proposed sites of attachment
* Transverse fold is sutured to the vestibular floor in a one or two layers closure
* Orifice opens 2.5 – 5cm further caudally
136
Where is the transverse fold sutured in the Monin technique?
To the vestibular floor in a retracted position.
137
What is the typical caudal extension of the urethral orifice after the Monin technique?
2.5 to 5 cm caudally.
138
Why is it important to avoid excessive tension on the transverse fold?
To prevent failure or complications in the sutures.
139
What suture material is recommended for the Monin technique?
USP size 2-0 absorbable suture material.
140
What disadvantage does the Monin technique have?
It does not extend the urethral opening as far caudally as other methods.
141
How might weight gain benefit a mare with urovagina?
It may improve perineal conformation and reduce urine pooling.
142
What postoperative consideration is recommended for mares after a Monin procedure?
Delayed breeding until healing is confirmed.
143
How can urovagina predispose mares to uterine infection?
Chronic urine presence in the vagina increases bacterial growth, leading to endometritis.
144
In young fillies that are experiencing urovagina what must be rulled out as cause beside conformation?
In young fillies that are experiencing urovagina, an** ectopic ureter** may be present and must be ruled out.
145
what is evaluated in the urine pooling with laboratoy tests and cytology?
bacteria, white blood bells, calcium carbonate crystals creatinine and urea
146
Medical treatment of vesicovaginal reflux such as manual evacuation of urine and gain weight may not be enough. What is the surgical treatment?
Definitive surgical treatment for vesicovaginal reflux involves modification of the external urethral orifice and providing a conduit to channel the urine caudally
147
Name the surgical techniques that exist to modify the external urethral orifice
1. Caudal relocation of transverse fold (Monin tx)
2. Brown tx
3. Shire technique
4. Mckinnon technique
5. Combined Brown and Mckinnon technqiue
148
How many urethral extension procedures are described for mares with urovagina?
four Brown, Shires, McKinnon, Combined Brown and McKinnon
149
What is a common complication of urethral extension procedures?
Fistula formation along the suture line.
150
When should a surgeon repair fistulas after initial surgery?
After tissue inflammation subsides.
151
Why is a 30 French Foley catheter used in these surgeries?
To ensure adequate lumen diameter and prevent urine contamination.
152
What complication can excessive lateral retraction cause?
Difficulty in apposition of the vestibular mucosa.
153
Where do the tissue flaps originate in the Brown technique?
At the level of the transverse urethral fold and continuing to just inside the labia (Figure 62-11)
154
Figure 62-9. Monin urethroplasty. (A) Incision of the transverse fold of the urethra. (B) Mucosal incisions in walls of the vestibule. (C) Caudal retraction of the transverse fold in preparation for suturing. (D) Completed Monin urethroplasty. (E) Two-layer closure using horizontal mattress pattern.
155
Figure 62-10. One complication of the caudal urethral extension procedures is fistula formation. Tips of scissors are sticking through the fistula.
156
Why is it important not to create holes in the tissue flaps?
Holes can compromise the integrity of the urethral extension.
157
What suture pattern is used for the ventral shelf in the Brown technique?
Continuous horizontal mattress pattern.
158
What is the role of the suture pattern on the ventral shelf in Brown tx?
It inverts the mucosa into the new urethral lumen.
159
What suture material size is used in the Brown technique?
USP size 2-0 absorbable material.
160
What suture technique is used for the dorsal shelves in the Brown technique?
Continuous horizontal mattress pattern that everts the mucosa.
161
How effective was the Brown technique in resolving urine pooling?
Successful in 16 of 18 mares 88%
162
Describe in detail the brown technique
- The free edge of the transverse urethral fold is incised horizontally with a scalpel, creating dorsal and ventral tissue flaps of equal thickness.
- The transverse incision is continued caudad along the vestibular wall to create
a dorsal and ventral shelf of vestibular mucosa and submucosa.
- Dissection dorsad and ventrad allows the flaps to be apposed on the midline without any tension. It is critical that the dissection generates tissue flaps large enough to result in a urethral tunnel of adequate diameter.
-The ventral shelves of tissue from opposing sites are sutured using USP size 2-0 absorbable material in continuous horizontal mattress pattern that inverts the mucosa of the ventral shelf into the new urethral lumen.
- The submucosa is closed using USP size 2-0 absorbable suture material in a continuous pattern.
- The dorsal shelves are sutured using USP size 2-0 absorbable suture material in a continuous horizontal mattress pattern that everts the mucosa into the vestibule.
163
What structure surrounds the urethral tunnel in the Shires technique?
Loose mucosa from the vestibule floor.
164
What size Foley catheter is used in the Shires technique?
30-French.
165
What is the main advantage of using a Foley catheter in the Shires technique?
To maintain the tunnel shape during surgery.
166
What suture pattern is used to form the tunnel in the Shires technique?
Interrupted horizontal mattress sutures.
167
How far does the tunnel extend in the Shires technique?
2 to 3 cm cranial to the vulva.
168
How successful was the Shires technique in treating urovagina?
Successful after a single surgery in 12 of 15 mares 80%
169
What is done to the dorsal mucosal ridges after tunnel creation in the Shires technique?
They are excised.
170
What type of suture material is used for final closure in the Shires technique?
2-0 absorbable suture material.
171
Figure 62-11. Brown technique of caudal urethral extension. (A) The transverse fold is split into dorsal and ventral shelves, and the incisions are continued caudad along the ventrolateral walls of the vestibule. (B) The first suture line inverts the vestibular mucosa into the new urethral lumen. (C) The second suture line apposes the submucosal tissues. (D) The third suture line everts the vestibular mucosa into the vestibule.
172
Figure 62-12. Shires technique of caudal urethral extension. (A) Vestibular mucosa is apposed over a Foley catheter using horizontal mattress sutures. (B) The everted mucosal ridge is excised. (C) The exposed submucosa is apposed using a continuous suture pattern.
173
Describe shires technique
- A 30-French Foley catheter is inserted through the urethral orifice into the bladder, and the balloon is inflated to secure the catheter (Figure 62-12). - Interrupted horizontal mattress sutures using 2-0 or 0 absorbable suture material are placed in the ventral vestibular mucosa and tied so that a tunnel is formed over the catheter.
-The tunnel must begin cranial to the urethral orifice and extend caudad to a point approximately 2 to 3 cm cranial to the vulva.
- The everted ridges of mucosa dorsal to the horizontal mattress sutures are excised using scissors after the completion of the tunnel. The cut edges of the mucosa are apposed using 2-0 suture absorbable material in a continuous pattern.
174
How does the McKinnon technique compare in size and strength to other techniques?
It creates a larger and stronger urethral tunnel.
175
Where is the initial horizontal incision made in the McKinnon technique?
In the mucosa of the transverse urethral fold, 2 cm cranial to the caudal free edge.
176
What suture pattern is used in the McKinnon technique?
Continuous horizontal mattress pattern.
177
What is the outcome of the closure pattern in the McKinnon technique?
The cranial aspect assumes a Y pattern.
178
What percentage of mares conceived after McKinnon surgery when bred during the same estrus cycle?
89%.
179
What was the overall pregnancy rate following the McKinnon technique?
67%.
180
What percentage of mares had a live foaling rate post-McKinnon surgery?
54%.
181
What is a common site for fistula formation in the McKinnon technique?
At the junction of the Y suture pattern.
182
How often did surgical failure occur with the McKinnon technique?
11.5% of mares experienced failure or dehiscence.
183
describe the McKinnon tx
-A horizontal incision is made in the mucosa of the transverse fold of the urethra 2 cm cranial to the caudal free edge (Figure 62-13).
- Incisions are made in the lateral walls of the vestibule approximately one half the distance from the floor of the vestibule. - Dissection of the tissue flaps continues ventrad until the flaps can be apposed on the midline without tension.
- The tissue flaps are closed using a one-layer technique with USP size 2-0 absorbable suture material in a continuous horizontal mattress pattern, inverting the mucosa into the lumen of the urethral tunnel.
- The initial dissection over the transverse urethral fold results in the cranial aspect of the closure assuming a Y pattern before the two suture lines meet on midline.
184
What is the initial dissection in the combined Brown and McKinnon technique similar to?
The Brown technique.
185
How far does the incision extend along the vestibule in the combined technique?
Approximately 2 cm cranial to the labia.
186
What suture pattern is used in the combined technique for the ventral flaps?
Continuous horizontal mattress pattern that inverts the mucosa into the urethral lumen.
187
Where is the most difficult area to repair in the combined technique?
The junction of the Y of the transverse urethral fold and vestibular flaps.
188
What additional suture layer may be used at the Y junction?
A third layer with a simple continuous pattern.
189
What is the purpose of maintaining a urinary catheter postoperatively in the combined technique?
To support healing and prevent urine contamination at the surgical site.
190
What is the initial step in the combined Brown and McKinnon technique?
Incise the transverse fold into dorsal and ventral shelves of equal thickness.
191
How far are the incisions continued in the vestibule combined Brown and McKinnon technique?
To a point approximately 2 cm cranial to the labia
192
What is the purpose of retracting the transverse fold caudally combined Brown and McKinnon technique?
To facilitate suturing and maintain proper alignment.
193
What suture pattern is used for the ventral flaps of the transverse fold combined Brown and McKinnon technique?
Continuous horizontal mattress pattern.
194
What should be done to the ventral flap mucosa during closure combined Brown and McKinnon technique?
It should be inverted into the urethral lumen.
195
What pattern is used to suture the dorsal vestibular flaps combined Brown and McKinnon technique?
Continuous horizontal mattress pattern, everting the mucosa into the vestibule.
196
Figure 62-13. McKinnon technique of caudal urethral extension. (A) Horizontal incision is made in the mucosa of the transverse fold. (B) Dissection is continued caudad high along the vestibular wall to create large tissue flaps. (C) Apposition of the tissue flaps is accomplished using a continuous horizontal mattress pattern. (D) Completed urethral extension.
197
Where is the suture pattern especially critical to avoid dehiscence combined Brown and McKinnon technique?
At the Y junction of the three tissue layers.
198
Why might a urinary catheter be maintained postoperatively combined Brown and McKinnon technique?
Based on surgeon preference for reducing contamination risk.
199
Describe in detail the combined Brown and Mckinnon technique
1. The midpoint of the caudal free edge of the transverse urethral fold is grasped with Allis tissue forceps and retracted caudad.
2. Suturing begins at the junction of the right ventral flap of the transverse fold and the right ventral flap of the vestibular wall.
3. A continuous horizontal mattress pattern using USP size 2-0 or 3-0 absorbable suture material is applied.
4. The mucosa of the ventral flaps should be inverted into the lumen of the urethral extension.
5. During closure it is important to retract the transverse fold caudad.
6. This suture pattern is continued caudad to the midpoint of the transverse fold, and the suture is tied.
7. The right dorsal flap of the transverse fold and the right dorsal flap of the vestibular wall are sutured next, using a continuous horizontal mattress pattern of USP size 2-0 or 3-0 absorbable suture material that everts the mucosa into the vestibule.
8. The procedure is repeated for the left side.
9. The remainder of the roof of the urethral tunnel is created by first suturing the right and left ventral vestibular tissue flaps, followed by suturing the dorsal flaps.
10. The ventral flaps are apposed using USP size 2-0 or 3-0 absorbable suture material in a continuous horizontal mattress pattern, which inverts the mucosa into the urethral lumen.
11. The dorsal flaps are apposed using USP size 2-0 or 3-0 absorbable suture material in a continuous horizontal mattress pattern, everting the mucosa into the vestibular lumen.
The most difficult part of the repair is the junction of the Y of the three tissue layers—the transverse urethral fold and right and left vestibular tissue flaps
200
What is a common cause of perineal lacerations in mares?
Foal’s forefoot catching on the dorsal transverse fold during parturition.
201
Figure 62-14. Combined Brown and McKinnon technique of caudal urethral extension. (A) The scalpel is used to split the free edge of the transverse fold into dorsal and ventral shelves. (B) and (C) Dorsal and ventral mucosal shelves are created by undermining the vestibular mucosa. The dissection should allow the shelves to meet on the midline without tension. (D) The midpoint of the horizontal shelf is retracted caudad, and the ventral shelf is closed using a continuous horizontal mattress pattern to invert the tissue into the newly created urethral tunnel in a Y pattern. (E) The dorsal shelves are sutured using a continuous horizontal mattress pattern to evert the tissue into the vestibule (a). An additional continuous everting suture is placed around the three portions of the Y and tied at the end to provide further support to this very vulnerable location (b). Close-up view of the new urethral shelf with the two everting patterns (c). (F) The completed urethral extension.
202
Figure 62-15. Completed urethral extension described in Figure 62-14 with a urinary catheter in place.
203
Figure 62-17. Appearance of a third-degree perineal laceration that is ready for repair. The rectal mucosa overhangs the intact shelf at the cranial extent of the laceration. Arrows point to the junction of the rectal mucosa and vestibular mucosa.
204
Figure 62-18. First stage of the two-stage repair of a third-degree perineal laceration. (A) The cranial-most extent of the rectovestibular shelf is incised in a horizontal plane. (B) The junction between the rectal mucosa and vestibular mucosa is delineated by a thin line of scar tissue. (C) Vestibular and rectal tissue flaps are created by dissecting along the line of scar tissue. (D) The vestibular mucosa is inverted into the vestibule using a continuous horizontal mattress pattern. The submucosal tissues are apposed using an interrupted pattern. (E) Completed first-stage repair.
205
Describe 1st degree perineal laceration
What type of laceration involves only vestibular mucosa and vulvar skin
206
What does a second-degree perineal laceration include?
Vestibular mucosa and submucosa and extends to perineal body muscles.
207
What predisposes mares with second-degree lacerations to pneumovagina?
Compromised closure of the labia.
208
What occurs in a third-degree perineal laceration?
Complete disruption of the rectovestibular shelf and anal sphincter
209
How are third-degree perineal lacerations managed initially?
Delayed surgical repair after wound healing and contamination control in 3 to 4 weeks time to avoid dehiscence
210
What dietary change may assist with fecal consistency before surgery for third degree perineal laceration?
Feeding wet bran mashes or pasturing on lush grass.
211
Name the surgical tx for perineal lacerations
Two stage repair (Aanes)
Single stage repair (Goetze)
212
In the two-stage repair, what is reconstructed in the first stage?
The **rectovestibular shelf **without repair of the perineal body --> 3 to 4 weeks later the se**cond stage or perineal repair** is performed to avoid obstipation
213
What instrument may aid access to the surgical site in the two-stage repair?
Balfour retractors or stay sutures.
214
How is tissue divided into rectal and vestibular shelves in the two-stage repair (first part of surgery)?
By a combination of sharp and blunt dissection.
Initial dissection begins craniad in a frontal plane at the level of the rectovestibular shelf. Thumb forceps can be used to place tension on the rectovestibular shelf to facilitate dissection. A combination of sharp and blunt dissection is used to divide the tissue into rectal and vestibular shelves (Figure 62-18). The rectal shelf should comprise two-thirds of the thickness and the vestibular shelf one-third. The plane of dissection is continued craniad for 3 to 5 cm. The cranial dissection is important for relieving tension at the tissue edges. The incisions are continued laterad and caudad along the scar tissue junction of the rectal mucosa and vestibular mucosa. The dissection is continued laterad until the tissue shelves can be apposed on the midline without tension. Once sufficient dissection has been achieved, reconstruction of the tissue shelves can commence.
215
What suture pattern is used for the vestibular shelf in the two-stage repair?
Continuous horizontal mattress pattern.
216
What is avoided when placing sutures in the rectal shelf?
Penetrating the rectal mucosa.
217
What follows reconstruction of the rectovestibular shelf in the two-stage repair?
Repair of the perineal body after 3 to 4 weeks.
218
describe the first suture line that apposes the vestibular shelves after dissection in the two stage repair
The first suture line apposes the vestibular shelves. A continuous horizontal mattress pattern of USP size 0 or 2-0 absorbable suture material is used to invert the vestibular mucosa into the vestibule. This pattern should be interrupted when approximately one-quarter to one-half of the vestibular defect is closed. This allows easier access for placement of the second set of sutures. The next row of sutures is placed dorsal to the first in an interrupted fashion in the perirectal and perivestibular tissues. Then one or two absorbable sutures are placed in a four-bite purse-string fashion.44 It is crucial that the rectal mucosa is not penetrated. The four-bite purse-string is placed by taking the first bite in the subrectal mucosal layer on the left; the second in the subvestibular mucosal tissue on the left; the third in the subvestibular tissue on the right; and the fourth in the subrectal mucosal tissue on the right, followed by tying the knot. These two suture patterns are alternated until the level of the dorsal commissure of the vulva is reached. After this the second stage is performed 3 to 4 weeks after
219
What does the second stage of a two-stage repair include?
Removal of epithelium from the perineal body and suturing at midline.
220
What technique does the Götze modification of the single-stage repair use?
Six-bite interrupted suture pattern.
221
Describe the sutures placemnt in the Götze modification of the single-stage repair uses a six-bite suture pattern
The first suture is placed at the cranial edge of the dissected shelf in the following sequence:
1. The first bite is deep in the left vestibular flap in a ventral-to-dorsal direction.
2. The second bite is in the left rectal submucosa, taking care not to penetrate the rectal mucosa. The third bite is in the right rectal submucosa.
3. The fourth bite is through the right vestibular flap in a dorsal to ventral direction.
4. The fifth bite reenters the right vestibular shelf medial to the fourth bite in a ventral-to-dorsal direction.
5. The sixth bite is in the left vestibular flap from dorsal to ventral and is positioned medial to the first bite.
When the suture is tied, the rectal edges should be apposed and the vestibular edges should be everted into the lumen of the
222
How does the six-bite pattern begin in the Götze modification?
With a deep bite in the left vestibular flap, ventral to dorsal.
223
What is the suture size material for single-stage repair or Gotze modification?
USP 2 absorbable material
224
What should be apposed in the six-bite suture technique?
The rectal edges should be apposed, and vestibular edges everted.
225
How far apart are the sutures placed in the Götze modification?
Approximately 1 cm apart.
226
What alternative method exists for a single-stage repair besides Götze’s?
The Aanes reconstruction technique or two stage technique.
227
How is failure of the suture line in the six-bite pattern mitigated (Götze modification)?
By ensuring sutures are not loose and are close enough together.
228
Rectovestibular fistula are usually what size and where are they located?
Fistulas are most commonly** 3 to 5 cm** in diameter and located cranial to the perineal body.
229
diagnosis
Rectovestibular fistulas result from a perineal laceration from the dorsum of the vestibule into the rectum, without disruption of the anal sphincter Figure 62-21. Rectovestibular fistula with manure contaminating the vestibule. Arrow points to the fistula.
230
What is a potential complication of a rectovestibular fistula?
Bacterial contamination of the vagina and uterus.
231
Why is a uterine biopsy generally not required before repair of third-degree perineal laceration?
Lack of correlation between biopsy grades and conception post-surgery.
232
What suture pattern helps with the tissue shelf between the rectum and vestibule in third perineal repair (single stage)?
Simple interrupted sutures.
233
What is emphasized when performing a two-layer or three-layer closure?
Alternating the suture pattern to avoid tension.
234
How does the Aanes technique reduce the risk of obstipation?
By dividing repair into two stages to allow gradual healing.
235
What’s the primary goal of perineal body reconstruction?
To restore the integrity and function of the anal sphincter.
236
describe the second stage of the two stage repair
It consists of removing the **epithelium from the triangular surface of the perineal body** and apposing these tissues on the midline (Figure 62-19), as described in the section on perineal body reconstruction.
The function of the anal sphincter is gained by suturing the tissues of the perineal body. No attempt is made to isolate and suture the muscle fibers of the anal sphincter. A Caslick procedure is performed if necessary.
237
Figure 62-19. Second stage of the two-stage repair of a third-degree perineal laceration. (A) The first-stage repair has healed and the mare is ready for the second stage of the repair. (B) The area of epithelialized tissue that is to be excised is outlined. (C) The submucosal tissues are apposed using interrupted purse-string sutures. This reconstructs the perineal body. (D) Completed second-stage repair.
238
Figure 62-20. Single-stage repair of a third-degree perineal laceration. Drawings show the use of a six-bite suture pattern to appose tissues
239
Figure 62-21. Rectovestibular fistula with manure contaminating the vestibule. Arrow points to the fistula.
240
Figure 62-22. Drawing showing dissection and repair of a rectovestibular fistula using the horizontal approach. (A) Completed dissection for repair of rectovestibular fistula. The fistula is divided into rectal and vestibular shelves. (B) The rectal shelf is sutured transversely. (C) The vestibular shelf is sutured longitudinally. (D) The rectovestibular fistula is repaired. The dead space created by the approach can now be closed.
241
Figure 62-23. Appearance of laceration at the dorsal aspect of the cervix during a speculum examination.
242
What does consist the surgical repair of rectovestibular fistula?
involve converting the fistula into a third degree perineal laceration and reairing using one of the techniques describe previously or horizontal approach
243
Describe the horizontal approach in rectovestibular fistula
a horizontal skin incision is made midway between the ventral aspect of the anus and the dorsal commissure of the vulva. A combination of blunt and sharp dissection is used to separate the perineal body. This plane of dissection is continued through the fistula for a distance of 3 cm (Figure 62-22, A).
Stay sutures or Allis tissue forceps can be used to help retract the tissue during dissection. It is important not to penetrate the rectum or vestibule before reaching the fistula. The surgeon can place their hand in the vestibule to help guide this dissection. The dissection should be such that the rectal shelf of tissue is thicker (two-thirds of the thickness) than the vestibular shelf (one-third of the thickness). The fistula in the rectal tissue is closed transversely using an interrupted Lembert pattern of USP 1 or 0 absorbable suture material (see Figure 62-22, B). The fistula in the vestibular shelf is closed longitudinally in a continuous horizontal mattress pattern. This results in suture lines that are at right angles to one another (see Figure 62-22, C and D). The dead space created by the approach is closed using USP 1 or 0 absorbable suture material placed in an interrupted purse-string pattern. The skin is closed in continuous or interrupted pattern. An alternative is to allow the dead space and skin to heal by second
intention
244
Describe the name of the surgical tx for rectovestibular fistula repair
Small fistulas sometimes conservative works
1. Aane technique
2. Gotze technique
3. horizontal approach through perineal body
4. Transrectal approach
5. Mucosal pedicle flap
245
Describe in detail the transrectal approach through perineal body
Exposure to the fistula was achieved using a modified Finochetto retractor placed into the rectum through the anus. The fistula was sharply dissected circumferentially to expose three tissue layers. Each layer was sutured separately in a horizontal orientation. The perineal body (middle layer) was sutured first in a simple continuous pattern. The rectal mucosa was sutured next using a continuous horizontal mattress pattern and oversewn using a simple continuous pattern. The retractor was removed from the anus and positioned in the vestibule. The vestibular mucosa of the fistula was sutured in a continuous horizontal mattress pattern.
246
describe in detial the mucosal pedicle flap technique for rectovestibular fistula repair
The edges of the fistula are débrided by full-thickness excision of 2 mm of the fistula margin. The fistula dimensions are assessed and a dorsally based U-shaped mucosal and submucosal pedicle flap is dissected from the vestibular wall. The flap is rotated 90 degrees so that the vestibular mucosa is continuous with the rectal mucosa covering the fistula. The flap is held in place by absorbable suture material placed in an interrupted pattern. Two of the three horses treated with this technique healed by first intention. The third horse required additional sutures to repair a partial dehiscence.
247
Figure 62-24. Photograph showing stay sutures placed to retract the cervix into the vestibule to facilitate repair. The sutures are placed to accentuate the defect in the cervix. Arrow points to the defect.
248
Figure 62-25. Appearance of a persistent hymen after it is exteriorized by an examiner.
249
What typically causes RVF formation?
It can result from a perineal laceration or unsuccessful repair of a third-degree rectovestibular laceration.
250
What suture pattern is used to close the fistula in the rectal tissue?
An interrupted Lembert pattern.
251
What suture pattern is used for the vestibular shelf in fistula repair?
A continuous horizontal mattress pattern.
252
What tool is used in the transrectal approach to visualize the fistula?
A modified Finochetto retractor.
253
What is the purpose of the mucosal pedicle flap technique in rectovestibular repair?
To cover the fistula with a rotated vestibular flap, promoting healing.
254
when should the surgery of cervical laceration should be performed?
Surgery should be performed during diestrus and no earlier than 3 weeks postpartum
255
What instrument is placed for repairing cervical lacerations?
modified Finochietto retractor with long blades
is very helpful in repairing cervical lacerations
256
Describe the three stay sutures to correct cervical laceration
GA - Trendelenburg position - retract the cervix caudally using stay sutures and repair in two layer sutures:
Three stay sutures using large-diameter suture material (USP 2) are placed in the external cervical os by hand or with the aid of long needle holders.
The stay sutures must be positioned so they accentuate the cervical defect and do not interfere with the dissection and repair of the defect. The long ends of the stay sutures should be tagged with a hemostat and the needle removed. An assistant should apply gentle, steady caudal traction on the stay sutures so that the surgeon has access to the cervix.
The cervix can usually be retracted to the level of the vestibulovaginal junction.
Allis tissue forceps are used to grasp the caudal-most scar tissue on each side of the cervical laceration.
The scar tissue is excised using a scalpel blade or scissors.
Following excision of the scar tissue, the three layers of cervical tissue should be evident.
Repair of the defect is accomplished in three layers. The first layer, the inner cervical mucosa, is the most difficult to close and is probably the most important. This layer is closed using USP 0 or 1 absorbable suture material in a continuous horizontal mattress pattern to invert the mucosa into the cervical lumen beginning at the most cranial aspect of the defect and working caudad. Following each bite, the surgeon should check whether the cervical lumen was penetrated and ensure that it is still patent.
The second layer in the cervical muscle is apposed using USP 1 absorbable suture material placed in a simple-continuous pattern.
The third layer, the outer cervical mucosa, is closed using USP 1 absorbable suture material placed in a simple-continuous pattern.
257
what is the prognosis of cervical lacerations correction?
Postoperatively, 64% of the mares conceived and 57% delivered a live foal.
258
How do transluminal adhesions affect the cervix?
They interfere with the cervix’s ability to open and close properly.
259
How do transluminal adhesions affect the cervix?
They interfere with the cervix’s ability to open and close properly.
260
What is a common neoplastic condition of the clitoris?
Squamous cell carcinoma.
261
What is a common infection harbored in the clitoral sinuses?
Taylorella equigenitalis, causing contagious equine metritis.
262
What congenital anomaly is most commonly observed in the mare’s genital system?
A persistent hymen.
263
What issue can arise from improper fusion of Müllerian ducts?
Dorsoventral bands across the cervix or a double cervix.
264
What surgical technique is used to remove a persistent hymen?
Full removal via surgical excision.
265
What condition is associated with atresia ani?
Rectovestibular fistula.
266
What causes varicosities around the vestibulovaginal fold?
Possible factors include elevated estrogen, venous changes, or perineal conformation.
267
What is a recommended salvage procedure for severe genital anomalies?
Ovariohysterectomy.
268
What rare congenital anomalies can affect the cervix?
Cervical aplasia, double cervix, and congenitally incompetent cervix.
