Cryptorchidism PDF

Cryptorchidism April 2023 Michelle Tucker, DVM, PhD, DACVS-LA Overview Anatomy Testicular Descent Equine Approaches Inguinal/Parainguinal Laparoscopy Ruminants Testicular descent Begins retroperitoneal Caudal to the kidneys Testicle grows very large to touch the inguinal ring Gubernaculum extends do...

Cryptorchidism April 2023 Michelle Tucker, DVM, PhD, DACVS-LA Overview Anatomy Testicular Descent Equine Approaches Inguinal/Parainguinal Laparoscopy Ruminants Testicular descent Begins retroperitoneal Caudal to the kidneys Testicle grows very large to touch the inguinal ring Gubernaculum extends down, peritoneum forms the vaginal process Epididymis descends first, then the testis shrink, gubernaculum shortens and dilates with the epididymis Testis passes into the inguinal canal->Birth Gubernaculum is still large and in the vaginal process, then regresses, testis slips down, vaginal rings contract to 1cm Anatomy Testis Spermatogonia Seminiferous tubules Epididymis Body Tail Coils up caudally to become the ductus deferens Gubernaculum-Three parts Cranial part - tail of epididymis to the testis Becomes proper ligament of the testis Middle part - tail of epididymis to parietal tunic Becomes ligament of the tail of the epididymis Caudal part - parietal tunic to bottom of scrotum Becomes the scrotal ligament BUT WHY DO WE CARE??? Why do we care? Which part of this is testicle? Which part is epididymis? Why do we care? Which part of this is testicle? Which part is epididymis? Why do we care? Cryptorchid testes fail to undergo the same coiling process with the epididymis It’s easy to mistakenly take the epididymis and leave the testicle in the inguinal ring with an incompletely descended testicle We can use the gubernaculum to find the cryptorchid testicle Equine Reproductive Procedures How the gubernaculum is helpful If we can find the gubernaculum, the epididymis and testicle are usually attached Traction pulls up the testicle Cryptorchidism-Equine Right: Inguinal Left: Abdominal A little over 50% of the time Possibly heritable Nonfunctional/low functioning testis/soft Diagnosis/Location Palpate the scrotum and inguinal rings externally Be safe Rectal palpation Ultrasound-transabdominal, transrectal Sometimes when you drop them, they relax and the testicle “floats” up in “high flankers”/inguinal testicles DO NOT REMOVE A DESCENDED TESTICLE WITHOUT ENSURING YOU CAN REMOVE THE UNDESCENDED ONE Diagnosis/Location: Have they been “castrated” before? Hormonal testing Baseline testosterone hCG stimulation-Give 6,000-12,000 units IV, collect serum 30-120 minutes later to measure testosterone Scars present? Stud behavior? Geldings can display sexual behaviors from interest to copulation Epididymis doesn’t produce testosterone 20-30% show continued aggression toward horses 5% toward people Inguinal testicle Sometimes you can get them pushed into the scrotum Sometimes you need to cut over them at the ring LATERAL IS LEGAL, MEDIAL IS NOT->This will keep you away from the penis If in the vaginal tunic, castration can be performed open routinely MAKE SURE YOU HAVE TESTICLE If in doubt, submit for histopath If you open the inguinal ring, you may need to close it to prevent evisceration Inguinal Approach Testicle in the inguinal ring or abdomen Can palpate the ring externally Incise skin, subcutaneous tissue Blunt digital dissection down to the ring Identify and exteriorize vaginal process Incise the process Identify gubernaculum/epididymis Photos courtesy of Dr. Jan Hawkins Inguinal Approach Light traction usually brings up the testicle IF the vaginal process is inverted into the abdomen: Can try to grasp and pull it up with sponge forceps Can feel for the internal extension of the gubernaculum testes (IEGT) or scrotal ligament Be very careful-genitofemoral n, pudendal vessels Photos courtesy of Dr. Jan Hawkins Parainguinal Approach Make the approach to the external inguinal ring Go 2cm medial to incise through the external abdominal aponeurosis, internal abdominal muscle, peritoneum Two fingers, “sweep the ring”-usually gubernaculum, ductus deferens, or epididymis will meet your fingers Parainguinal Approach Gentle traction brings the testicle up Ligate, emasculate Close the sheath Easier closure, avoid the vessels/nerve in the inguinal ring More invasive? Laparoscopy Minimally invasive Ability to explore the abdomen Standing is cheaper But may have to approach both sides Recumbent Laterality doesn’t matter Can also pull an inguinal testes into the abdomen Other Approaches Suprapubic paramedian approach 5-10 cm lateral to ventral midline; preputial orifice then caudally Large subcutaneous vessels Through the rectus abdominis sheaths and muscle Can fit a hand through the incision Not good for a field situation Flank incision Standing, through the paralumbar fossa Need to know what side As a GP “High flankers” are probably fine Inguinal canal testicles maybe AVOID ABDOMINAL ONES Unless you’re really really comfortable and can be completely aseptic PALPATE before dropping PLEASE, please do not remove the down testicle until the up one is out Scar tissue makes our lives more complicated, but still better than a septic peritonitis Ruminants More recognizable whether it is in the scrotum or not Ectopic Abdominal Ectopic-cut down over the testicle Photo credit: Dr. Jan Hawkins Ruminant Abdominal Cryptorchid Approaches Small 50lb: Flank Laparascopic Paramedian Approach Dorsal recumbency 5-10 cm incision on the retained side Halfway between the umbilicus and scrotum, inguinal region and midline External rectus sheath, separate the rectus muscle fibers, then internal rectus sheath and peritoneum Sweep for the testicle Ductus deferens inserts at the bladder-follow it Double ligate the spermatic cord and remove Close-internal rectus, external recuts, skin Flank laparotomy/laparoscopy Larger ruminants Paralumbar approach Left or right can be very dorsal Can be up by the kidney Subperitoneal Photo credit: Dr. Jan Hawkins Porcine Cryptorchids Ectopic or abdominal History-have they been castrated? Dorsal recumbency Paramedian as with ruminants Short spermatic cord Ligate ductus deferens and spermatic cord separately frees up the spermatic cord Closure: internal rectus sheath, external rectus sheath, skin Questions?