Caudal Repro Surgery Flashcards
Methods of urethral Extension
- Brown
- Shires
- McKinnon
- Combined Brown McKinnon
Surgical treatment options for urovagina
1) Caudal relocation of the transverse urethral fold (Monin technique)
2) Caudal urethral extension (Brown, Shires, McKinnon, Brown-McKinnon)
3) Caslick, Gadd or Pouret if dt pneumovagina
Surgical treatment options for pneumovagina
1) Caslicks vulvuloplasty
2) Gadd episioplasty (perineal body reconstruction)
3) Pourets perineal body transection
Blood supply to the mammary gland
Majority from external pudendal
Lesser contribution from mammary branch of ventral perineal aa
Venous drainage from external pudendal and ‘milk vein’ - superficial abdominal vein
Layers of the teat wall (from in to out)
Teat sinus is line by double layer cuboidal epithelium
Submucosa
Intermediate layer = connective tissue then smooth muscle layers
Stratified squamous epithelium externally
Teat anatomy
Types of teat obstruction
Type I = <30% of mucosal surface in the teat sinus involved
Type II = >30% mucosal surface in the teat sinus involved
Type III = between the teat sinus and the mammary gland sinus
Type IV = extend from the teat sinus to the gland sinus
Tissues involved in each degree of perineal lacerations
1st degree: Skin and vestibular mucosa of the dorsal commisure only
2nd degree: Skin, mucosa and submucosa of the vestibule, plus variable amounts of musculature of the perineal body. No involvment of rectal mucosa
3rd degree: As above with involvement of perineal septum, anal sphincter, rectal submucosa and mucosa
What is this injury?
How should repair be timed?
List the different methods for repair.
Third degree perineal laceration
Delay of the repair by at least 6 weeks (minimum reported is 3 weeks). Some state upto 12 weeks or until second intention healing is complete (ie complete epithelial healing)
- Single-stage* repair methods include modified Goetz technique (6 bite suture pattern) or Utrech repair method (UGA).
- Two* stage repair is the Aanes technique
Briefly describe the steps in single stage repair of 3DPL reported by Frietman et al (VS 2019)
1) Marker incisions made for new dorsal commissure and distal margin of external anal sphincter. Large stay suture in each side of the vulva
2 Incisions made at cranial margins of the defect, extended laterally and caudally along the line of demarcation on each side to the anal sphincter marker incisions in the perineal skin
3) Vestibular mucosa and submucosa dissected from the the underlying rectal tissue with Metz; mobilise enough tissue to create new shelf with minimal tension; need firm thick rectal layer and a relatively thinner vestibular layer
4) Utrecht suture pattern( USP) w 2-0 Vicryll used to appose the lateral dissected parts to the central perirectal tissues on left and right sides, aiming to get symmetrical V or Y shaped closure (mucosa everts into the rectal lumen)
5) USP was continued to reconstruct the internal anal sphincter by juxtaposing the palpable ends of the ruptured sphincter muscle
6) Horizontal mattress polypropelene tension suture pre-placed at the level of external anal sphincter (tightened over gauze at the end), followed by complete reconctruction of external anal sphincter (2-0Vicryll; interrupted), to accomodate 2 fingers
7) 2 more layers of sutures placed to reinforce the rectal shelf in continuous USP as above
8) Perineal body reconstruced with modified episioplasty, involving closure of left and right vestibular
What are the main differences in the technique reported by Frietman 2019 (VS) for repair of 3DPL vs prev reports?
What were the success rates reported with this procedure?
Single-stage repair as reported by Goetz
1) Sx performed UGA
2) Repair delayed by 3-4 months until 2nd intention healing complete (vs 3-8wk reported by others)
3) Extensive - 14d peri-op fasting
4) Vestibular approach involving 3 layer rectal shelf closure (Utrect suture pattern) and PB reconstruction
Outcome: 90% successful repairs with single surgery
10% required RV fisular repair in a second sx
6/7 used for breeding again in the next but 1 season bred successfully
9/13 used for riding
Label the diagram of perineal anatomy
a - retractor clitoridis
b - ext anal sphincter
c - levator ani
d - levator ani (subanal loop)
e - levator ani (ventral loop)
f - urethralis
g - ext anal sphincter (caudal/superficial part)
h - perineal spetum
i - crus clitordis
j - constrictor vestibuli
k - constrictor vulvae
Describe ideal vulval conformation
Vertical (<10° deviation in a horizontal plane) - vulval anterior slope of 80˚ to horizontal is optimal, while an angle <50˚ is likely to result in pneumovagina (Caslick 1973)
Ventral commissure should be located caudal and ventral to the ishial arch
Approx 2/3 of the vulval cleft should be ventral to the ishial arch/pelvic brim (see pic for ishial arch) - ideally >80% ventral (<4cm vulva dorsal to pelvic brim ideally)
Vulva should be muscular and resist separation (constrictor vulva mm)
What is the Caslick index and how are the results interpreted?
Caslick index = (distance between dorsal commissure and pelvic brim (cm)) x (vulval angle)
(Larger distance from dorsal commisure to pelvic brim means more of vulva is dorsal to ishial arch. Vulval angle measured as deviation from vertical i.e. 10° off vertical)
Interpretation of results:
<100 → normal
100-150 → further evaluation required
>150 → Caslick’s vulvoplasty required
Vascular supply and innervation to the vulva
Internal pudendal aa/vv
Pudendal and caudal rectal nn provide sensory & motor innervation
Which structures make up the perineal body?
- The muscular connection between external anal sphincter and constrictor vestibuli
- Internal anal sphincter
- The subanal decussation of the retractor clitoridis mm
- The fibrous plate of the perineal septum (passes craniodorsally from the vestibule to the rectum)
- Subanal loop of levator ani
Anatomy of the clitoris
Homologue of the penis, located at the ventral commissure of the vulva
Clitoris glans is approx 2.5cm diameter containing erectile tissue similar to the CCP
Clitoral fossa surrounds the glans is located ventrally and laterally
Body of the clitoris is approx 5cm long and attaches by 2 crura to the ishial arch
Anatomy of the cervix
An extension of the uterine body with its caudal portion located in the cranial aspect (fornix) of the vagina
Caudal portion is the external cervical os, covered by vaginal mucosa
Tubular muscular structure lined with mucosa forming many longitudinal folds. Functions as a sphincter to keep the uterus separate.
The 3 ‘seals’ of the caudal reproductive tract
1) Vulva - the constrictor vulvae muscles of the labia
2) Vestibular sphincter - the vestibulovaginal junction
3) The cervix
Incompetency of any of these barriers may lead to contamination and infertility
Methods of caudal epidural
- Use sacrococcygeal or first intercoccygeal space (first obviously moveable)
- For the first intercoccygeal space - use 20-g, 7.5-cm (3-in) spinal needle positioned just cranial to the DSP of the 2nd coccygeal vertebra & inserted at a 30° angle to the skin, directed craniad
- Use hanging drop technique to confirm penetration & injection should be met w minimal resistance
- Alternate technique described is a 38-mm (1.5-in) 18-g needle positioned over the 1st intercoccygeal space with the bevel of the needle positioned forward and inserted at a 75° angle to the skin
What procedure is demonstrated in the diagram?
Describe the steps
Local +/- sedation
Remove 4-8mm stip of mucocutaneous junction (care to incl dorsal commisure)
Close in continuous pattern (Ford interlocking shown) with 2-0 abs or non-abs material.
Remove suture 10-12d later and evaluate for fistulas in the repair
Care re urovagina if Caslicks is too long, should be able to fit a tube speculum in as a guide
Which procedure is pictured?
What are the main indications?
Perineal body reconstruction → Gadd technique
Indicated to treat pneumovagina
Req. when vulvar and vestibular muscles have become ineffective, esp in older multiparous mares (repeated stretching) or following foaling injury (2 degree perineal laceration)
Goal of sx is to restore integrity of the dorsal aspect of vestibule & vestibular sphincter function
Improve competency of VV sphincter by ↓ diam of vestibule + enlarging perineal body
Describe the steps involved in perineal body reconstruction (Gadd episioplasty)
Sedation w epidural/local. Retract labia with stay sutures.
Incision is made along the mucocutaneous junction of the labia in a dorsoventral direction & extended cranially along the dorsal commissure of the vestibule to the level of the vestibulovaginal junction
Dissection is continued sub-mucosally such that triangular flaps of mucosa approximating the shape of the perineal body are excised. The procedure needs to result in the vulva being oriented more vertically
Closure is as follows
- Vestibular mucosa is closed w USP 2-0 or 0 absorbable suture in a horizontal mattress pattern, inverting the mucosa into the vestibule (pic shows continuous pattern)
- The submucosal tissue is closed from the cranial aspect of the vestibule w USP 0 or 1 absorbable suture in interrupted pattern
- The labial skin is apposed as for the Caslick procedure.
Allow 4 weeks of sexual rest following the procedure
Episiotomy is usually required at the time of foaling since the diameter of the vestibule is decreased by this procedure
Which surgical technique is pictured and who was it described by?
What are the main indications?
Perineal body transection. Descr. by Pouret
Used to treat pneumo (+/- uro) vagina in mares with poor perineal conformation (usually older, multiparaous mares w extremely sunken anus when majority of vulva above pelvis) by allowing the vulva to attain a more normal, vertical orientation
Describe the surgical steps in the Pouret procedure (perineal body transection)
- Sedated w epidural or local inf to perineal body (40-70ml 2% lido)
- 4-6cm horizontal skin incision is made midway between the ventral aspect of the anus and the dorsal commissure of the vulva, continued ventrad for 3-4cm on either side of the vulva
- Combo of blunt and sharp dissection is used to extend the dissection in a cranial direction through the muscles of the perineal body for 8-14cm until the connections between the rectum and caudal reproductive tract have been severed - a hand in the vestibule is useful to prevent inadvertent entry to the rectum or peritoneal cavity
- Dissection continued until the vulva has attained a normal vertical position without traction & when connections btwn rectum + caudal repro tract completely severed
- Large, unsightly wound can be left open to heal by 2˚ intention OR skin closure either transversely or in a T-shaped config - no attempt made to close the dead space created
- Delay natural cover until sx site healed, but can breed with AI immediately
This surgical treatment has been used for a mare with urovagina
What is the surgical procedure?
What are the main advantages and disadvantages of this procedure?
Caudal relocation of the transverse urethral fold - Monin urethroplasty
Advantages + simple to perform
Disadvantages - only extends the opening caudally by a small amount vs urethral extension (2-2.5cm caudal to its natural position)
- beneficial only if the condition is mild and conformational abnormalities minimal - will not resolve severe vesicovaginal reflux
- may increase difficulty of subsequent procedures eg urethral extension
How is a Monin urethroplasty performed?
What condition is it used to treat?
- Grasp the centre of the transverse urethral fold w allis tissue forceps and retract caudally
- Horizontal incision through the transverse fold, splitting it into dorsal and ventral shelves
- With thumb forceps, the ventral shelf is positioned along the ventrolateral walls of the vestibule
- Mucosal incisions are then made in the walls of the vestibule at the proposed site of attachment. The transverse urethral fold is sutured to the vestibular floor in the retracted position, creating the extension.
- Can do 1 or 2 layered closure with 2-0 absorbable material
- Creates a urethral orifice that opens 2.5 to 5 cm more caudally after completion of the procedure
Used to treat urovagina
NB only sucessful if the condition/conformational abnormalities are mild/minimal
Which surgical procedure is pictured?
Describe the steps?
What other surgical methods are available to achieve the same outcome?
The Shires technique of caudal urethral extension
- Suture the ventral vestibular mucosa under minimal tension over a foley catheter, from 2-3cm cranial to the urethral orifice to 2-3cm cranial to the vulva, w interrupted 2-0 or 0 absorbable horizontal mattress sutures
- Excise the everted mucosal ridges dorsal to the catheter and appose the mucosal edges w 2-0 absorbable simple continuous pattern
Other methods of caudal urethral extension incl. Brown, McKinnon and McKinnon Brown
Which technique of caudal urethral extension is pictured?
Describe the steps
What are the main advantages of this technique?
McKinnon technique
- Horizontal incision in the transverse urethral fold, approx 2cm cranial to its caudal free edge
- Continue incisions caudally in the vestibular walls, remaining dorsally (approx 1/2 way from top to bottom of the vestibule) to the vulva labia
- Dissestion of vestibular flaps continues ventrally until they can be apposed beyond midline without tension
- Caudal cut edge of transverse fold free flap is reflected caudad & vestibular free flaps reflected mediad, and the 2 are apposed with 2-0 absorbable in a single layer of continuous horizontal mattress sutures inverting the mucosa into the lumen of the urethral tunnel
- Close left fold to left vestibular mucosal flap, then the same on the right forming a Y cranially, then continue apposition of left and right vestibular flaps caudally on midline.
+ This tecnique produces a larger and stronger tunnel tha Brown or Shires techniques
Describe the Brown technique for caudal urethral extension
- Horizontal incision in the caudal free edge of transverse urethral fold creating dorsal & ventral shelves
- Continue incisions caudally at the same DV level in the vestibular mucosa to the vulval labia
- Dissect dorsal and ventral flaps such that they can be apposed on midline without tension
- Ventral shelves of tissue from opposing sites are closed with USP 2-0 absorbable material in a continuous horizontal mattress pattern - to invert the mucosa of the ventral shelf into the new urethral lumen (ie like a Cushing from above)
- Close submucosa in continuous pattern with the same suture
- Dorsal shelves are apposed w 2-0 absorbable material in in a continuous horizontal mattress pattern that everts the mucosa into the vestibule
Which technique of caudal urethral extension is pictured?
Describe the steps
Combined Brown-McKinnon technique
- Horizontal incision in caudal free edge of transverse urethral fold (as for Brown)
- Continue the incisions caudally along the ventrolateral walls of the vestibule to a point approximately 2 cm cranial to the labia (as for Brown)
- Submucosal dissection dorsally and ventrally to create dorsal and ventral flaps that can be apposed on midline without tension
- Grasp midpoint of the ventral shelf of trans urethral fold and begin closure as follows:
- Suturing begins at the junction of the right ventral flap of the transverse fold and the right ventral vestibular flap. Use continuous horizontal mattress pattern of USP 2-0 or 3-0 absorbable suture, to invert the mucosa into the lumen of the urethral extension.
- During closure it is important to retract the transverse fold caudad. This suture pattern is continued caudad to the midpoint of the transverse fold, and the suture is tied.
- Repeat for the dorsal flaps of the same side, this time everting the mucosa into the vestibule
- Repeat both layers for the opposite side
- Then suture the right and left ventral vestibular tissue flaps, w USP 2-0 or 3-0 absorbable suture in a continuous horizontal mattress pattern, to invert the mucosa into the urethral lumen (ie Cushing) followed by suturing the dorsal flaps w the same suture in a continuous horizontal mattress pattern, to evert the mucosa into the vestibular lumen
*
Most common comlication of urethral extension surgery
Fistula formation, esp at the Y in tecniques that rx in Y-shaped closure (McKinnon, combined Brown-McKinnon)
Describe the 2-stage repair method (Aanes) for 3° perineal lacerations (TDPL)
Remember Aanes has 2 A’s = 2 stage
Stage 1:
- RV shelf is reconstructed WITHOUT repair of the perineal body
- Use a combo of sharp & blunt dissection to divide the tissue horizontally into rectal & vestibular shelves; the rectal shelf should be 2/3 of the total thickness and vestibular 1/3.
- Continue dissection cranially for 3-5cm - this is important for relieving tension at the tissue edges
- Incisions are continued laterad and caudad along the scar tissue junction of the rectal mucosa and vestibular mucosa; dissection cont until tissues can be apposed on midline w/out tension
- 1st suture line apposes vestibular shelves w continuous horizontal mattress 0 or 2-0 absorbable suture to invert the vestibular mucosa into the vestibule, interrupt the pattern when 1/4-1/2 is closed making placement of the second set of sutures easier
- Next row is dorsal to the 1st in an interrupted fashion in the perirectal and perivestibular tissues.
- Then 1 or 2 absorbable sutures are placed in a four-bite purse-string fashion; first bite in the subrectal mucosa on the left, second in the subvestibular mucosal layer on the left, then the subvestibular tissue on the right and sub rectal on the right before tying
- Must take GREAT CARE TO AVOID PENETRATION OF RECTAL MUCOSA
- These 2 suture patterns are alternated until the level of the dorsal commissure of the vulva is reached. This does NOT repair the anal sphincter or perineal body
Stage 2:
- 3-4w later-△shaped epithelium removed from the surface of perineal body & apposed midline
- Function of anal sphincter is gained by suturing the tissues of the perineal body. No attempt is made to isolate and suture the muscle fibres of the anal sphincter
- Caslick is performed if necessary
Describe the modified Gotze single stage repair method for TDPL
- Initial dissection as for the 2-stange; sharp & blunt dissection to divide the tissue horizontally into thicker rectal & thinner vestibular shelves
- Continue dissection cranially for 3-5cm - important for relieving tension at the tissue edges
- Incisions are continued laterad and caudad along the scar tissue junction of the rectal mucosa and vestibular mucosa; dissection cont until tissues can be apposed on midline w/out tension
- The Gotze modification uses a 6 bite interrupted suture pattern w USP 2 absorbable suture
- 1st bite is deep in the left vestibular flap in a ventral-to-dorsal direction.
- 2nd bite is in the left rectal submucosa, (care not to penetrate the rectal mucosa).
- 3rd bite is in the right rectal submucosa.
- 4th bite is through the right vestibular flap in a dorsal to ventral direction.
- 5th bite reenters the right vestibular shelf medial to the fourth bite in ventral-to-dorsal direction.
- 6th bite is in the left vestibular flap from dorsal-ventral & positioned medial to the first bite
- When the suture is tightened the rectal edges should be apposed and the vestibular edges should be everted into the lumen of the vestibule
- Sutures should be placed approx 1cm apart, imperative they arent loose as will compromise repair
- Closure of the rectal mucosa has been proposed but is not necessary
- Repair is continued to a point 4-6cm cranial to the cutaneous perineum, at which point the perineal body is repaired as for body reconstruction
- Caslick as necessary
What is this injury?
Describe a trans-rectal approach to repair
RV fistula
Transrectal repair technique:
- Delay repair at least 3 weeks post injur. Standing sedated w epidural. Aanes modified Finochetto retractors into rectum
- Edges of fistula dissected sharply circumferentially w 12 blade to expose 3 layers (caudal edge dissected by inverting edge w/ Babcock forceps) → exposure of 3 tissue planes - rectal mucosa, perineal body, vag mucosa
- Each layer closed separately in transverse fashion (ie left to right), 2 from the rectum, 1 from vestibule
- 1st: perineal body by simple cont
- 2nd: rectal mucosa inverted continuous Connell (don’t worry about suture in the rectum)
- 3rd: Vest/vag mucosa apposed + inverted from within the vestibule w continuous horiz mattress
- Post op care similar to PL repair but little attention to faecal softening necessary
- Delaying breeding to following season NOT NECESSARY - consider breeding same cycle!
Describe surgical management of an RV fistula via a horizontal approach through the perineal body
Horizontal skin incision midway between ventral aspect of anus & dorsal commissure of the vulva
Blunt & sharp dissection to separate perineal body - dissection continued through the fistula for a distance of 3 cm, such that the rectal shelf of tissue is 2/3 the total thickness
Take care NOT to penetrate the rectum or vestibule before reaching the defect
Fistula in the rectal tissue is closed transversely using an interrupted Lembert pattern of USP 1 or 0 absorbable suture
Fistula in the vestibular shelf is closed longitudinally in a continuous horizontal mattress pattern, resulting in suture lines that are at right angles to each another
Dead space 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.
Alternative is to allow the dead space and skin to heal by second intention
Describe the mucosal pedical flap techniqe for repair of RV fistulas
What is the expected outcome?
- 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
- Flap rotated 90 degrees so that the vestibular mucosa is continuous with the rectal mucosa covering the fistula, secured w 10-13 SI sutures of 5 metric polyglactin 910 at 10mm intervals
- 2/3 tx horses healed by first intention, 1 had partial dehiscence
Describe repair of a cervical laceration
- Sx performed during DIOESTRUS - and no earlier than 3 weeks postpartum (alternatively during oestrus immediately after breeding).
- Can breed and perform sx once enters dioestrus
- Sedation & epidural. Aanes modified Finocetto retractors in the vestibule
- Caudal retraction of the cervix achieved w stay sutures, place tactically to accentuate the defect. Knowles cervical forceps can be used but are more traumatic - Can usually retract to the level of the VV junction
- Scar tissue excised from the defect to expose the 3 layers of cervical tissue → closed individually
- 1) Inner most layer is the cervical mucosa - most difficult and most important. Closed w USP 0 or 1 absorbable in a continuous horizontal mattress pattern to invert the mucosa into the cervical lumen beginning at the cranial most aspect of the defect and working caudally. After each bite should check that the lumen hasn’t been penetrated and that it is still patent
- 2) Cervical muscle apposed with USP 1 in simple continuous pattern (holding layer for sutures)
- 3) Outer cervical mucosa with USP 1 absorbable suture material placed in a simple-continuous pattern
- Avoid breeding 35-40d post repair
- 2 and 1 layer closures are also described - 2 layer closure: Inner cervical mucosa w/ muscular layer (simple cont or cont horiz mattress) & Outer layer (simple cont) OR 1 layer closure:
Simple cont through outer layer into muscular layer. Suture bites approx 1cm apart
You are presented with an 18 month old filly
What is the diagnosis?
What is your treatment?
Persistent hymen
Break down the membrane w scissors
