Small Animal Sx - OVH

saxamixi's version from 2016-04-19 15:55

intro/ anatomy

Question Answer
The uterine body likes to sit where in the body?between the bladder and the colon
what is a visibly noticeable difference between cat and dog repro tract?difference notable @ level of cervix- female dog you can palpate and see easily. cat- no true demarcation between cervix and uterine body.
where are the ovaries located in the body?located at caudal pole of kidneys
where are the uterine horns located in the body?dorso-lateral in body cavity
where is the uterine body located in the body?located between urinary bladder and colon, adjacent to ureters
where is the suspensory ligament? what do you need to do with the suspensory lig? from top of ovary to caudal pole of kidney and fans out around caudal pole of kidney, also goes up to ribs-- you will need to break this lig to get the ovary out
why don't you want to pull too hard on your ovarian pedicle?Left ovarian v drains into Left renal v-- don't wanna damage the renal vein
WHERE do you want to rupture the suspensory lig?Near ca pole of kidney is where all fibers get together and then fan out- so easier to break when fanned out, so break there
what is the proper ligament? what are you usually doing with this lig sx-ly?goes from ovary to uterine horn, where you place first hemostat to bring up and try to break suspensory lig.
which structure has the ureters passing through it, so extreme caution must be used in handling it?broad lig
what should you know about the broad lig?URETERS PASS THROUGH IT, USE CARE
Why must you be careful about breaking the suspensory ligament, esp if near the ovary instead of near the kidney?fat can block vision of pedicle- can then break vessels when trying to break susp lig
what is the green arrow pointing to? precautions about this? green arrow pointing to suspensory lig-- there is fat covering the lig and the pedicle associated with it, you can break vessels if you arent careful
all vessels are located in what two anatomical locations?all vessels are located in mesovarium and mesometrium
how do you pick up the ovary in order to manipulate it and find the suspensory lig?pick up by the proper lig

surgical procedure of OVH

Question Answer
what approach?ventral midline or possibly flank incision
which incisions should you avoid?keyholes!
from where to where do you make your incisions for OVH?incision from umbilicus up to 4-6 cm cr to pubis (TO pubis if uterus distended at all)
If the uterus is distended, how might you change your incision for the OVH?instead of stopping 4-6cm short of pubis, go all the way down to the pubis
if using a flank approach, how is this done/variations based on sp? (benefit of flank incision?)(less likely for dehiss--> stuff coming out of abd) do on both sides of dog. may do one incision for cat for both ovaries.
is there is big diff between a OVH and a OVE?not really, if you just remove the ovaries the uterus and related tissues will atrophy
When making your ventral midline incision in the bitch, what must you be careful of and why?MAMMARY TISSUE! cutting it can lead to mastitis, esp since milk is a good culture medium
the bladder is over the body of the uterus, what precaution should you use when moving it out of the way?GENTLE! don wanna damage innervation of neck of bladder
(step 1 after incision) how do you go about properly using the spay hook?take spay hook facing outward and slide against wall of cavity until at floor. Then turn spay hook 180* inward, and scoop against paralumbar fossa up to midline, hopefully hooking the uterine horn, and the pull straight up. scoop to grab uterine horn and then pull straight up- if oblique fashion, will disengage.
(step 2) once you have hooked the uterus and brought it out of the body, what do you do?Place curved hemostat on proper lig...grab hemo and uterine horn, pull on both. if good exposure, can see suspensory lig-- then can try to strum/break the suspensory lig (careful or can cause hematoma) can grab metz sciccors and clip- first nick, then break, then vessels are there.
explain what's happening to the proper lig vs the suspensory lig during the OVHProper lig: clamped to manipulate the ovary. Suspensory lig: torn to allow elevation of the ovary
(step 3) once you have broken the suspensory ligament, what do you do next?find the most avascular portion of the mesovarium, which looks like a transparent window. pierce this with a straight instrument and slide up and down
(step 4) once you have pierced a hole in the mesovarium, what do you do?Three clamp technique the ovarian pedicle (clamps near ovary, not near uterine horn) (more about this on diff card)
3 Clamp technique: which clamps do you use? where do you put them?3 Rochester-Carmalt forceps are placed across the ovarian pedicle through the opening in the mesovarium, near the ovary side. Curved points pointing up toward ovary. The hemostat closest to the ovary is the DISTAL HEMOSTAT (The most distal clamp must be proximal to the entire ovary)
why do you want the distal hemostat to still be SUFFICIENTLY proximal to the ovary?If there is fat in the ovarian bursa obscuring the ovary, you do not want to risk accidentally leaving a small piece of ovary behind--> can lead to stump pyometra (don't make pedicle too short though, you need room for 2 ligatures)
If you are concerned about leaving ovary tissue behind because of a lot of fat in the ovarian bursa, what can you do?open the bursa and allow yourself to visualize the ovaries
explain the basics of how to perform the 3 clamp techniqueA circumferential ligature is placed around the tissue crushed by the proximal clamp. A second ligature is placed distal to the first ligature-- Hemoclips can also be used. then the tissue is transected between the middle and distal clamps. (when tying first 2 throws of each ligature, you must "flash" to allow blood to flow bc when clamped vessels are stretched out and you would be tying it tight but when released lig would be too loose)
how do the L and R uterine horns differ in their position?left uterine horn more caudal than right (bc Left kidney is left behind)- may have to dig more cranial.
why might a pregnant bitch of a bitch which has had litters before more likely to have bleeders than a immature bitch?bc the uterine veins are bigger and more friable and more likely to tear
(step 5) once you have ligated the ovarian pedicle with the 3 clamp technique, what do you do next?The mesometrium is divided lateral to the uterine vessels (already divided in pic). can be divided via cutting or tearing- in fat dogs, ligation may be required. (this is so you can lift up the whole body and horns)
(step 6) after mesometrium has been divided lateral to uterine vessels, what do you do? Sp diff?(1) DOGS: uterus is ligated and transected directly cranial to the cervix (2) CATS: uterus is ligated and transected at about the caudal 1/3 body, since there is no obvious cervix. (pic is of dog with cervical body being obv from externally)
explain how the uterus(/uterine vessels) is ligated (details about step 6)If merited (large vessels, been preg before)The vessels on both sides of the uterus are ligated separately with 3 clamp technique and circum and trans ligs. Make sure to leave long suture ends as tags for handling, till they are later cut short. Then place 3 Rochester-Carmalt forceps across the uterine body and vessels. Circumfrential lig w/ uterine vessels and body included. then cranial to that, transfixing. Remember, if mated/breeded dog- tissues bigger- ligate seperately the uterine vessels- go a lil bit through uterine wall (not through lumen! just to keep in good practice bc dont want to do that with pyometra) leave long tags- to retrieve tissues back for exploration.
(step 7) after you have ligated and removed the uterus, what do you do?explore abd cavity before closure- check for sponges, fish for stumps (3 stumps total) check for bleeders. use natural retractors (mesoduodeimun on R mesocolon on L). check all 360* degrees of uterine stump- check for ureters!! make sure they weren't accidentally ligated....
(Step 8) after double checking all stumps and ligatures, how do you do your closure?START CA TO CR with simple interrupted or simple continuous
why is it so easy to accidentally get the ureters in your ligation?LOOK AT THE ANATOMY! ureter runs very closely to uterine body. Risk hydroureter or worse. Kidney killer!
who are hemoclips esp. useful in?young or small patients (dogs and cats)
ALWAYS check for sponges-- what is the idiot-proof sponge?RFID- radio frequency ID tags- hoop passes over patient and will make a sound if sponge left behind. (also sponges with radio-opaque line in them to see on rads if forgotten)
If you leave a sponge in the abdomen, what complication might happen?can get adsorbed by intestines and sucked into lumen--> FB/blockage
how do you go about clamping the uterine body of a cat when you can't see the cervix?so go to most ca aspect of uterine body, and then place most ca forceps. if too cr, uterine horns could be separate inside.
what is the normal contaminant for pyometra?E. coli
if you are going to be removing a pyometra uterus, what should you do differently?bigger incision, be extra gentle bc tissue extra friable
how might a uterine torsion present?sudden pain in abdomen. If you untwist it, you cannot leave the accumulated fluid in it- must remove
what congenital malformity might you run across when performing OVH?uterine agenesis
what is ovarian remnant syndrome, what probs does it cause?when piece of ovary left behind, piece of ovary takes command--> hormonal issues or stump pyometra
4 important things you must do for post-op OVH care?(1) exercise restriction (2) prevention of self-mutilation (E-collar) (3) isolation of patients in estrus: mating in early post-operative period can cause severe abdominal bleeding and/or peritonitis (4) good pain control
What is vaginal hyperplasia/what causes it? How do you sx tx?path due to hormonal imbalances, mucosa of vagina gets bigger (have had several several imbalances of estrus cycles for it to become hyperplastic) so then eventually it starts to protrude. Ddx prolapse. Sx Tx: episiotomy gains access to vagina and keep track of urethral opening.... do episiotomy! recc a spay as well
if you are working with genitals- what should you know about (C)TVT?if see pt with this, handle with gloves. debate if its zoonotic. can be in dog's genitalia, nose, eyes, other cavities. tx with vincristine.
In summary, steps for OVHIncision VM from umbilicus to just above pubis--> use spay hook to fish out uterus via uterine horns--> grab ovary by proper ligament with hemostat, then break the suspensory ligament--> pierce hole in mesovarium's avascular portion--> 3 clamp technique the ovarian pedicle--> lateral to uterine vessels dissect mesometrium so uterus can be lifted up--> either all together, or do vessels separate, 3 clamp the uterine vessels and the uterine body, just above the cervix--> check all your stumps/sponges/etc--> close Ca to Cr simple interrupted or continuous.