Histological Investigation of the testicular nerves at the castration site in geldings
Castration is one of the most common surgical procedures in equine medicine and associated with a number of postoperative complications such as swelling, infection, haemorrhage, peritonitis, funiculitis, omental herniation and eventration. But what happens with the testicular nerves after crushing a...
| Autor principal: | |
|---|---|
| Formato: | Second cycle, A2E |
| Lenguaje: | Inglés Inglés |
| Publicado: |
2017
|
| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/10135/ |
| _version_ | 1855571643515011072 |
|---|---|
| author | Bengtsdotter, Emma Angelina |
| author_browse | Bengtsdotter, Emma Angelina |
| author_facet | Bengtsdotter, Emma Angelina |
| author_sort | Bengtsdotter, Emma Angelina |
| collection | Epsilon Archive for Student Projects |
| description | Castration is one of the most common surgical procedures in equine medicine and associated with a number of postoperative complications such as swelling, infection, haemorrhage, peritonitis, funiculitis, omental herniation and eventration. But what happens with the testicular nerves after crushing and severing during the procedure? An injured nerve can respond with degeneration and/or regeneration. If the distal segment of the nerve is missing, such as after castration, the newly regenerating nerve fibres can be tangled in scar tissue, forming bundles of nerve fibres, creating a neuroma. In human medicine neuromas are well known a cause of pain sensations after different types of nerve injuries, for example in relation to amputations.
Studies of animals have documented the existence of neuroma formation after somatic nerve injuries, and in a few cases signs of pain originating from such a neuroma have been described. Neuroma formation on the testicular nerves at the castration site in geldings has never been investigated before. Can neuroma develop as response to injury of the testicular nerves? If so could this cause pain in geldings? What could this pain lead to and which consequence could this have for the horse? As a first step to answer these questions, the aim of this pilot study was to investigate if neuromas can form at the castration site on the testicular nerves in geldings.
Stumps of twelve spermatic cords were collected from six geldings (between 6-25 years of age and all of different breeds) admitted from the University Animal Hospital in Uppsala, Sweden for post mortem examination after euthanasia for unrelated reasons. Owners consent for examining the spermatic cords were obtained. The tissue samples were fixed in formalin and the spermatic cord was sectioned in a distal, mid and proximal segment. These where dehydrated and embedded in paraffin before sectioned in 4 μm longitudinal sections for histological investigation. The slides were stained with Haematoxylin and Eosin (HE) and Masson´s Trichrome (MT). After examination in light microscope twelve slides with presumptive neuroma formation were selected for further investigation. Expression of nerve specific enolase (NSE) for visualisation of nerve fibres and S-100 protein for detection of Schwann cells were examined in slides after immuno-histochemical labelling. The expression of nerve growth factor (NGF) by immuno-histochemical labelling was investigated as a possible pain marker.
Neuromas were found in six spermatic cords belonging to four geldings. The neuromas consisted of an irregular and abnormal distribution of nerve fibres dispersed in and surrounded by connective tissue. Most of them were classified as delimited and containing Schwann cells. One neuroma was classified as dispersed, containing nerve fibres dispersed in a large area of connective tissue without Schwann cells. All neuromas expressed mild immunostaining of NGF, but no conclusions regarding clinical relevance from this could be drawn.
This pilot study has proved that neuromas of the testicular nerves indeed may form at the castration site in geldings. Though, further studies are required to establish the extent of neuromas in this location. The influence of castration methods and the possible consequences for the individual horse need to be investigated to answer important questions on the possible welfare implications of this elective surgery. Possible clinical implications include documentation of presence of inguinal pain, unexplained hind limb lameness or movements, back pain or unexplained behavioural problems in geldings. |
| format | Second cycle, A2E |
| id | RepoSLU10135 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés Inglés |
| publishDate | 2017 |
| publishDateSort | 2017 |
| record_format | eprints |
| spelling | RepoSLU101352017-04-21T11:01:43Z https://stud.epsilon.slu.se/10135/ Histological Investigation of the testicular nerves at the castration site in geldings Bengtsdotter, Emma Angelina Veterinary science and hygiene - General aspects Castration is one of the most common surgical procedures in equine medicine and associated with a number of postoperative complications such as swelling, infection, haemorrhage, peritonitis, funiculitis, omental herniation and eventration. But what happens with the testicular nerves after crushing and severing during the procedure? An injured nerve can respond with degeneration and/or regeneration. If the distal segment of the nerve is missing, such as after castration, the newly regenerating nerve fibres can be tangled in scar tissue, forming bundles of nerve fibres, creating a neuroma. In human medicine neuromas are well known a cause of pain sensations after different types of nerve injuries, for example in relation to amputations. Studies of animals have documented the existence of neuroma formation after somatic nerve injuries, and in a few cases signs of pain originating from such a neuroma have been described. Neuroma formation on the testicular nerves at the castration site in geldings has never been investigated before. Can neuroma develop as response to injury of the testicular nerves? If so could this cause pain in geldings? What could this pain lead to and which consequence could this have for the horse? As a first step to answer these questions, the aim of this pilot study was to investigate if neuromas can form at the castration site on the testicular nerves in geldings. Stumps of twelve spermatic cords were collected from six geldings (between 6-25 years of age and all of different breeds) admitted from the University Animal Hospital in Uppsala, Sweden for post mortem examination after euthanasia for unrelated reasons. Owners consent for examining the spermatic cords were obtained. The tissue samples were fixed in formalin and the spermatic cord was sectioned in a distal, mid and proximal segment. These where dehydrated and embedded in paraffin before sectioned in 4 μm longitudinal sections for histological investigation. The slides were stained with Haematoxylin and Eosin (HE) and Masson´s Trichrome (MT). After examination in light microscope twelve slides with presumptive neuroma formation were selected for further investigation. Expression of nerve specific enolase (NSE) for visualisation of nerve fibres and S-100 protein for detection of Schwann cells were examined in slides after immuno-histochemical labelling. The expression of nerve growth factor (NGF) by immuno-histochemical labelling was investigated as a possible pain marker. Neuromas were found in six spermatic cords belonging to four geldings. The neuromas consisted of an irregular and abnormal distribution of nerve fibres dispersed in and surrounded by connective tissue. Most of them were classified as delimited and containing Schwann cells. One neuroma was classified as dispersed, containing nerve fibres dispersed in a large area of connective tissue without Schwann cells. All neuromas expressed mild immunostaining of NGF, but no conclusions regarding clinical relevance from this could be drawn. This pilot study has proved that neuromas of the testicular nerves indeed may form at the castration site in geldings. Though, further studies are required to establish the extent of neuromas in this location. The influence of castration methods and the possible consequences for the individual horse need to be investigated to answer important questions on the possible welfare implications of this elective surgery. Possible clinical implications include documentation of presence of inguinal pain, unexplained hind limb lameness or movements, back pain or unexplained behavioural problems in geldings. Kastrering är en av de vanligaste kirurgiska åtgärderna inom hästmedicin. Väl kända komplikationer är svullnad, infektion, blödning, peritonit, funikulit, nätframfall och evisceration. Men vad händer egentligen med testikelns nerver som både krossas och skärs av under ingreppet? En skadad nerv kan svara med degeneration och/eller regeneration. Om nervens distala segment saknas, så som vid kastration, kan de nyregenererade nervfibrerna trassla in sig i ärrvävnad och bilda ett neurom. Neurom har inom humanmedicinen länge varit känt för att kunna orsaka smärtupplevelser efter olika typer av nervskador, exempelvis efter amputation. Hos djur har man undersökt och påvisat förekomst av neurom vid vissa nervskador och i några fall har man även kunnat visa tecken som tyder på att neuromen orsakar en smärtupplevelse hos djuret. Neurom på testikelns nerver efter kastration hos häst har aldrig tidigare undersökts. Bildas det neurom på testikelns nerver efter kastration? Skulle dessa neurom kunna orsaka smärta hos valacker? Vad skulle denna smärta kunna leda till och vilken betydelse kan den ha för hästen? Denna pilotstudie avsåg som ett första steg att svara på frågan om neurom kan bildas på testikelns nerver vid kastrationsstället hos valacker. Stumpen av tolv funiklar insamlades från sex valacker som skickats för obduktion från Hästkliniken vid Universitetsdjursjukhuset i Uppsala, efter ägarnas medgivande. Funikelstumparna fixerades i formalin och sädessträngen där nerverna löper skars sedan ut i ett distalt-, mitt-, och proximalt segment som efter dehydrering och inbäddning i paraffin snittades i 4 μm longitudinella snitt för histologisk undersökning. Snitten färgades med Haematoxylin och eosin (HE) samt Masson´s trichrome (MT). Efter undersökning i ljusmikroskop valdes tolv snitt med misstanke om neurom ut för vidare undersökning. Med hjälp av immunohistokemi undersöktes uttryck av nerv specifikt enolase (NSE) för visualisering av nervfibrer och S-100 protein för påvisande av Schwannska celler. Uttryck av nerve growth factor (NGF) undersöktes med immunohistokemi som en möjlig smärtmarkör. Totalt sex sädessträngar hos fyra valacker innehöll neurom. Neuromen bestod av en oregelbunden och onormal utbredning av nervfibrer, utspridd i och omgiven av bindväv. De flesta var avgränsade och innehöll Schwannska celler. Ett av neuromen klassificerades som utspritt och bestod av nervfiber utspridda i ett större område av bindväv, utan förekomst av Scwannska celler. Neuromen uttryckte mild immunofärgning av NGF, men någon slutsats gick inte att bestämma utifrån detta. Denna pilotstudie har påvisat förekomst av neurom i vävnad vid kastrationsstället hos valacker. Men ytterligare studier behövs för att kunna svara på hur vanligt förekommande det är, samt om det skiljer sig mellan olika kastrationsmetoder. Men främst vilken betydelse det har för den enskilda hästen. Kan ett neurom på testikelns nerver orsaka obehag eller en smärtupplevelse hos hästen? Skulle detta kunna vara orsaken till inguinal smärta, en oförklarlig hälta, ovilja att utföra en viss rörelse, beteendeproblem eller en dålig bakbensaktivitet hos vissa valacker? 2017-04-11 Second cycle, A2E NonPeerReviewed application/pdf en https://stud.epsilon.slu.se/10135/1/Bengtsdotter_E_170421.pdf Bengtsdotter, Emma Angelina, 2017. Histological Investigation of the testicular nerves at the castration site in geldings. Second cycle, A2E. Uppsala: (VH) > Dept. of Clinical Sciences (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-715.html> urn:nbn:se:slu:epsilon-s-6350 eng |
| spellingShingle | Veterinary science and hygiene - General aspects Bengtsdotter, Emma Angelina Histological Investigation of the testicular nerves at the castration site in geldings |
| title | Histological Investigation of the testicular nerves at the castration site in geldings |
| title_full | Histological Investigation of the testicular nerves at the castration site in geldings |
| title_fullStr | Histological Investigation of the testicular nerves at the castration site in geldings |
| title_full_unstemmed | Histological Investigation of the testicular nerves at the castration site in geldings |
| title_short | Histological Investigation of the testicular nerves at the castration site in geldings |
| title_sort | histological investigation of the testicular nerves at the castration site in geldings |
| topic | Veterinary science and hygiene - General aspects |
| url | https://stud.epsilon.slu.se/10135/ https://stud.epsilon.slu.se/10135/ |