Large Ani. Sx- Equine Male Urogenital 1

wilsbach's version from 2015-11-09 03:03

retained testicle intro + preoperative considerations

Question Answer
CQ: (T/F) The internal inguinal ring is a slit in the internal abdominal oblique muscle.F (its in transverse fascia)
CQ: what is a "high flanker"?synonym for cryptorchid
CQ: (T/F) cryptorchids are difficult to manageT
CQ: between what muscles does the inguinal canal lie?The inguinal canal is between the internal and external abdominal oblique muscles.
synonyms for retained testicles? (4)Cryptorchid, High Flanker, Rig or Ridgling, Original
when is it ethical/unethical to sx correct genetic defects on animals?Performance of surgical or other procedures in all species for the purpose of concealing genetic defects in animals to be shown, raced, bred or sold as breeding animals is unethical. However, should the health or welfare of the individual patient require correction of such genetic defects, it is recommended that the patient be rendered incapable of reproduction.
where does ruminant retained testicle tend to be/ not be? how would you remove it?Almost Never in the Abdomen.... Usual Subcutaneous Close To Ring= "ectopic testicle". A skin incision can be made directly over the testicle and the testicle can be removed using an emasculator
where does swine retained testicle tend to be? how would you remove it?Have retained abdominal testicles... second part is TRICK QUESTION: It is not economically sound to remove a retained testicle in pigs- Meat quality is not affected if intact males are slaughtered at market weight
when do testicles descend in foals?Testicles are usually present in the scrotum at birth!
can you palpate the scrotum and determine if the testicles are descended at birth in the foal?It is impossible to differentiate between the testicle and the bulb of the gubernaculum, in the foal, by palpation. (It is not uncommon for horsemen to report that a foal had testicles present in the scrotum at birth and the these testicles were pulled back into the abdomen--->In this situation the mass that was palpated in the scrotum was the gubernaculum)
after what age is it unlikely that the testicle will find its way to the scrotum naturally (equine)If a colt still has a testicle retained at two years of age it is possible but unlikely that it will find its way to the scrotum naturally
how difficult is a retained testicle horse as compared to a stallion?Horses with a retained testicle are usually considerably more difficult to manage than are stallions
what is the most common reason a cryptorchid horse is presented for sx?The most common reason that a cryptorchid is presented for surgery is because he is difficult to manage
can you resposition a testicle in the scrotum surgically?it is considered unethical
after what age should a cryptorchid horse be reported?>4yr
is horse cryptorchid heritable?This is considered by many to be a heritable condition
(pic) descent of testicle
you should attempt to pre-operatively palpate the testicle. If deep palpation of the inguinal canal is unsuccessful, what else can you try? (2)(1) Palpation following sedation or tranquilization- Relaxation of the cremaster muscle many times allows testicles to be palpated (2) Rectal examination- Sometimes possible to palpate the testicle in the abdomen or to palpate the vas deferens going through the internal inguinal ring
what imaging modality can be used to try to locate a retained testicle?ultrasound
if you are worried about an undescended testicle, why should you look for scars?It is possible that at a previous surgery the descended testicle was removed and the retained left in place (This is a very poor practice but a definite possibility)
Estrogen panels are difficult to run, but if you are able, how much estrogen might indicate a retained testicle versus no testicle?> 400 pg/ml = Testicle. < 100 pg/ml = No Testicle
explain how you can use serum testosterone levels to determine if there is a retained testicle (procedure and interpretation of results)(Determine prior to and after injection of human chorionic gonadotropin!!) Draw an initial sample--> Inject 10,000 units of HCG intravenously to a 450 kg horse--> Draw samples at 30 and 60 minutes post injection: Geldings have a testosterone level of essentially zero. Animals with testicular tissue have from 2 to 9 nano mols/liter pre-injection. Animals with testicular tissue show an increase in level following HCG injection to >7 nano mols/liter
you can use gas chromatography to test for testosterone levels in what kina sample?urine
which is more common- unilateral or bilateral retention?unilateral to bilateral retention is 13:1 (so, unilateral much more common)-- Most animals presented for surgery have one testicle retained in the inguinal canal and the other in the scrotum
are testicles retained more on the L or on the R?Testicles are retained on the right and left with almost equal regularity
how do testicle sizes differ before birth, how does this affect the side in which there is a retained testicle? surgical implications? Testicles are retained on the right and left with almost equal regularity!! however, The left testicle is larger in the fetus just prior to testicular descent. One study found that 75% of the left undescended testicles were in the abdomen and 42% of the right undescended testicles were in the abdomen (The right testicle, if retained, is many times present in the inguinal canal). Therefore, prior to surgery, depending on which testicle is retained, the surgeon has some idea of how difficult the surgery might be.
when might stimulation of the descent of the testicle be a good option, and how would you do this? (2 ways to do)This is sometimes effective if the testicle is close to the inguinal ring (determine with U/S). (1) use HCG- inject IM 2x a week for 4 weeks. (2) GnRH or deslorein have been suggested but unless the colt is sexually mature he doesn't produce LH and as a result does not respond
aside from the gubernaculum, what else can be mistakenly palpated for a testicle in the scrotum?epididymis

Sx approaches to retained testicle?

Question Answer
When do you use the inguinal approach?(this is through the inguinal canal) Use this approach if there is a question about the location of the testicle
where is the incision done for a parainguinal approach, and what is the benefit of using this approach?Approach is 4 to 5 cm anterior and medial to the external inguinal ring. It is easier to repair this area with suture than it is to suture the external inguinal ring
when are ventral midline or paramedian approaches indicated? what is the difficulty with these approaches?These approaches may be indicated for bilateral retention although both abdominally retained testicles can normally be removed through a single inguinal or parainguinal approach. The ventral midline approach is complicated by the location of the penis and prepuce (The skin incision must be made lateral and then the penis and prepuce reflected to gain access to the caudal midline)
what is the major benefit to doing a flank approach? What is the only situation in which this technique is used, though?Major advantage is that it may be performed on a standing animal. HOWEVER, One must be sure that the testicle is retained in the abdomen before using this approach. (It is quite difficult to remove a testicle that is retained in the inguinal canal, with a flank approach)
in the flank approach, how can the testicle be located?The testicle can be located by following either the mesorchium or the vas deferens to the testicle
following the mesorchium to find the testicle really only works in what approach? HOW do you do this?only of value in the flank approach. You: Identify the mesorchium at the caudal pole of the ipsilateral kidney---> Follow the mesorchium to the retained testicle
Inguinal/parainguinal approach--> If there is unilateral testicular retention, do you remove the descended or the undescended testicle first?always remove the retained testicle first (cleaner procedure)
Inguinal/parainguinal approach--> where is incision made and how do you start looking?A skin incision is made just medial and anterior to the external inguinal ring-->Careful blunt but not extremely traumatic dissection to the external inguinal ring (Rough handling of tissue will cause a problem if the wound is closed under suture)
inguinal/parainguinal approach--> Suggested methods for locating the testicle if they are not present in the inguinal canal (3)(1) Tension on the inguinal extension of the gubernaculum (2) The use of sponge forceps to pick up the vaginal process (3) Insert the fingers through the ruptured vaginal process and feel in the immediate area for the gubernaculum
inguinal/parainguinal approach--> explain how you use Tension on the inguinal extension of the gubernaculum to try to find the testicleCarefully examine the anterior medial aspect of the external inguinal ring for the inguinal extension of the gubernaculum--> Carefully apply traction to deliver the vaginal process and make an incision in it to deliver the epididymis and testicle.
inguinal/parainguinal approach--> explain The use of sponge forceps to pick up the vaginal process in order to find the testicleInsert sponge forceps into the depths of the inguinal canal--> Open the jaws of the sponge forceps and while pressing against the peritoneum close the forceps to pick up the vaginal process--> Apply traction to the vaginal process to bring it bring it to the level of the external ring and incise the vaginal process--> Apply traction to the gubernaculum (which should be attached to the vaginal process) to deliver the epididymis and testicle
(pic) location of parainguinal incision?
inguinal/parainguinal approach--> If you are unable to find the testicle with the initial techniques (tension on inguinal extension of gubernaculum, sponge forceps, probing with fingers) you will need to enter the abdomen. how do you do this with an inguinal/ parainguinal approach?The fingers and then the hand are used to dilate the inguinal canal. Groping blindly in the abdominal cavity hoping to find the testicle is seldom productive. what you should do is: Locate the vas deferens at the neck of the bladder! This technique is always successful in locating the retained testicle unless someone has previously removed the epididymis and not the testicle. This is done by: The hand is inserted through the parainguinal approach, the inguinal canal or any abdominal incision. Palpate at the neck of the bladder for the ampulla, which is in the genital fold. Trace the ampulla distally to the vas deferens and then to the epididymis and finally the testicle
how do you close the parainguinal approach?Simple interrupted or simple continuous sutures are placed in the abdominal fascia
how do you close the inguinal approach?Closure can be difficult because the surgeon is working in a hole with reduced exposure....suggested method: Place a long piece of absorbable suture through the eye of a blunt pointed hernia needle. Tie the suture to form a loop. Insert the needle through the abdominal fascia just anterior to the inguinal ring. Place the needle through the loop of the suture to form a larks head knot. Close the inguinal ring with a simple continuous suture. To end the suture: Cut the loop and place the needle on one end of the suture. Pass the needle and one arm of the suture through the tissue and tie the suture ends.
If the procedure to locate the testicle abdominally has been done in less than ideal/dirty circumstances, what might you wanna do? (related to closure)it might be indicated to not suture all layers of tissue--> The suggested management is to close the external inguinal ring or, in the case of a parainguinal approach, the abdominal fascia with suture and leave the subcutaneous tissue and skin open. ------ Another possibility with the inguinal approach is to not suture the inguinal canal or subcutaneous tissue but to pack the inguinal canal with gauze, suture the skin and remove the skin sutures and gauze in 24 to 48 hrs. This relies on the inflammatory response to close the inguinal canal and prevent herniation.With this approach one must be sure that the gauze is not forced into the peritoneal cavity (Best to perform a rectal to be sure this has not happened)
explain how to do the laproscopic procedure to find the testicle when standingSurgical preparation of the flank and the umbilicus. Distention of the abdomen with carbon dioxide or nitrous oxide with a teat cannula inserted through the umbilicus or the flank. Insertion of a laparoscope trocar and sleeve through the flank. Remove the trocar and insert the laparoscope--> locate the testicle (If not easily located the vas deferens can be followed cranial from the ampulla to the testicle). Produce an instrument portal or portals. Ligate the spermatic artery and vas deferens, Testicle can be left to atrophy but is usually removed
how does a retained testicle differ in appearance from a descended one?smaller, lacks a vaginal tunic
explain how to do the laproscopic procedure to find the testicle when under anesthesiaDorsal position with head lowered by 30 degrees (tredelenburg Position)--> Requires positive pressure ventilation. Teat cannula is inserted through the umbilicus and the abdomen distended. Teat cannula is removed and a laparoscopic trocar and sleeve inserted. Laparoscope introduced and the internal inguinal rings are visualized. Testicle is located. Instrument portals are made. Spermatic artery and vas deferens are ligated. Testicle can be removed or left to atrophy