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Biomedical subjects

M A van der Velden

Publications and source records attributed to M A van der Velden.

At least 19 recordsLinked to original sources
PubMed2006

[Unsuccessful laparoscopic castration in a cryptorchid Frisian stallion].

A 2-year-old unilateral inguinal cryptorchid Frisian stallion was castrated by bilateral laparoscopic intra-abdominal spermatic cord transection. Because blood testosterone levels were still high on postoperative day 7, both testicles were removed using an open approach. Pathology revealed the presence of vital Leydig-cells in both testes. Failure of the laparoscopic castration in this horse was attributed to an alternate blood supply to the testes by vessels derived from the cremaster and/or external pudendal artery.

Animals↗
PubMed2006

The complex blood supply to the equine testis as a cause of failure in laparoscopic castration.

REASONS FOR PERFORMING STUDY: Intra-abdominal ligation/ transection of the spermatic cord may result in necrosis of the testis; castration of abdominal cryptorchids via laparoscopy has therefore become common. Notwithstanding some adaptations of the technique, a small percentage of operations fail, prompting research into the anatomical background and clinical relevance of the procedure. HYPOTHESIS: That an alternate blood supply may prevent complete necrosis of the testis after spermatic cord transection. OBJECTIVE: To establish the prevalence of the problem in normal and cryptorchid stallions. METHODS: In a preliminary study, the spermatic cords of 8 normal stallions were ligated and transected at different sites and in various manners. Five weeks later the testes were removed and the vitality of both the testes and epididymes was evaluated. In a prospective clinical trial, intra-abdominal spermatic cord transection was performed in 241 cryptorchid and normal stallions. In cases of surgical failure, the testes were removed and histology performed. RESULTS: Examination of the specimen removed from the 8 animals of the preliminary study revealed that all epididymes were completely or largely spared. All except one testis were completely necrotic. In the patients that underwent surgery all abdominally retained testes (n = 123) were necrotic, while 5 out of 88 inguinally retained and 8 out of 236 normally descended testes had partially survived. The pattern of survival differed between inguinally retained and normally descended testes. The epididymes of these 13 horses were (largely) vital. The (partial) survival of the epididymes and inguinally retained testes was ascribed to an alternate blood supply via anastomosing vessels derived from the cremasteric artery. A tributary from the external pudendal artery was considered responsible for the partial survival of normally descended testes. CONCLUSIONS AND POTENTIAL RELEVANCE: After intra-abdominal transection of the entire spermatic cord, 5.6% of inguinally retained and 3.4% of normally descended testes failed to become completely necrotic, as a result of an alternate blood supply via the cremasteric and/or external pudendal artery. Therefore, laparoscopic castration without orchidectomy cannot be recommended as a trustworthy method for castration of inguinal cryptorchids and normal stallions.

Animals↗
PubMed2005

[Eosinophilic keratitis in a horse].

In this case report a 20-year-old horse with unilateral eosinophilic keratitis is presented. The occurrence, clinical symptoms, histological findings and treatment of this ocular disorder are described and discussed against the background of relevant literature. Local administration of 0.1% dexamethason was successful.

Animals↗
PubMed2004

[Rectal tears in the horse: a literature review].

Rectal tears are a relatively rare complication of rectal palpation, mating, or dystocia, and idiopathic rectal perforation is an incidental finding. Rectal tears can be classified according to a 3 or a 4-grade system. This article describes medical and surgical treatment for rectal tears.

Animals↗
PubMed2004

[Rectal tears in the horse: malpractice or an unfortunate accident?].

Rectal tears are a relatively rare complication of rectal palpation, mating or dystocia, and idiopathic spontaneous occurrence of rectal perforation has also been described. Rectal tears have been classified in a three or a four-grade system. Immediate recognition of the fact that a tear has been made and prompt action will improve the horses chance of survival, and is the best defence of the veterinarian against legislation. There is no clear explanation why rectal tears sometimes occur. A questionnaire of the Netherlands Equine Veterinary Association revealed that rectal tears occurred both to inexperienced veterinarians and to very experienced colleagues, working with or without a probe for ultrasonography. In the opinion of the authors, the approach in the legislation of rectal tears should be that a rectal tear is only considered 'malpractice' if the veterinarian obviously acted carelessly. However, this would create the ridiculous situation that it seems better for the veterinarian-client relationship when the veterinarian confesses to 'careless' rectal palpation. This point needs further clarification, and perhaps an 'insurance of the horse for rectal palpation' will be the solution. Further, retrospectively over the last ten years, the problem is often not 'making a rectal tear', but 'lacking recognition of making a tear'. Whenever a rectal tear is suspected, the veterinarian must assess its severity, discuss the problem openly with the owner and apply appropriate treatment including referral.

Animals↗
PubMed2004

[Incarcerated umbilical hernia in the horse: a case with a review of the literature].

Umbilical hernias are common in foals. This article provides a review of the literature and presents a case of an 1.5-year-old Friesian mare with an incarcerated umbilical hernia. After reposition of the incarcerated intestine (with a lot of effort), the practising veterinarian referred the mare to the Department of Equine Sciences. Preperforative peritonitis was diagnosed, presumed to be caused by necrotic bowel. After laparotomy, this tentative diagnosis was confirmed. The necrotic part of the small intestine was resected and intensive medical treatment was started. Initially, the mare recovered well, but seven days after surgery her general condition deteriorated and she had to be euthanized. At necropsy, impaction of the stomach and rupture of the stomach wall were found. The impaction was probably a result of the generalized peritonitis.

Animals↗
PubMed2003

[Splenectomy in a dressage pony: end of sports career?].

A 14-year-old Arabian cross-bred gelding was referred to the University Clinic because of mild, recurrent signs of colic for 5 days. The pony showed icteric mucous membranes, haemolytic blood, and dark coloured urine. Internal examination did not give a clear diagnosis. Unidentified intra-abdominal strands were found and haemorrhagic abdominocentesis led to the decision to perform an exploratory laparatomy. An extremely enlarged spleen was the sole finding. A splenal biopsy sample was taken and surgery was completed. The pony remained colicky, so the spleen was examined by ultrasonography. After this examination, the tentative diagnosis 'tumour of the spleen' was made and splenectomy was performed. Pathological examination of the spleen revealed splenomegaly caused by infarctions of unknown origin. Eight weeks after surgery, the pony started again in dressage competition. Six months after splenectomy, the pony won the provincial dressage competition.

Animals↗
PubMed2002

[Priapism in the stallion].

A review of the literature is given concerning the anatomy and pathophysiology of the equine penis with regard to priapism: a prolonged erection of the penis not associated with sexual arousal. Several treatment options, such as flushing of the corpus cavernosum penis with heparinized saline and the creation of shunt between the corpus cavernosum penis and the corpus spongiosum penis are discussed. Subsequently, a case of priapism in a stallion following the injection of acepromazine, is discussed. The priapism resolved after the corpus cavernosum penis was flushed with the stallion under general anaesthesia.

Acepromazine↗
PubMed2001

Short-and long-term evaluation of surgical treatment of strangulating obstructions of the small intestine in horses: a review of 224 cases.

A retrospective study was carried out of 224 horses operated for strangulating small intestine obstructions. Fifty-four horses were euthanized and 5 horses died during surgery which means that 165 (73%) were allowed to recover. Of these, 53 horses were euthanized or died in the clinic and 112 (50%) were discharged from the hospital. Of 90 horses available for follow-up 1 year postoperatively, 76 (84%) were still alive. The most important causes of death or reasons for euthanasia in the direct post-operative period were post-operative paralytic ileus, (adhesive) peritonitis and intra-abdominal haemorrhage. After discharge from the hospital the reasons were (adhesive) peritonitis and (recurrent) colic. Of the horses which survived for at least 1 year, 16% sometimes suffered from colic, 12% experienced problems with incisional woundhealing and 4% suffered from jugular vein thrombosis. All were in good or reasonable condition and 88% performed at (approximately) the same level as before the operation. The type of surgical intervention (i.e. enterotomy, enterectomy) did not significantly influence the outcome of surgery, whereas the type of anastomosis did. End-to-end jejunojejunostomy had a better prognosis than side-to-side jejunocaecostomy. It was concluded that strangulating obstructions of the small intestine still carry a poor to guarded prognosis. Mortality was highest in the direct peri-operative period. Once discharged from hospital, prognosis can be considered to be fair to good. Attempts to improve outcome should be directed at a better handling of the ileal stump during surgery and at the prevention of post-operative ileus and the formation of adhesions.

Anastomosis, Surgical↗
PubMed2000

Closure of the abdominal wall at the umbilicus and the development of umbilical hernias in a group of foals from birth to 11 months of age.

The closure of the body wall defect at the umbilicus was studied in relation to the development of umbilical hernias in a group of 44 normal foals, 25 of which were followed from birth until five months of age, and 19 from birth until 11 months of age. At birth, 19 of the foals had a defect in the body wall at the umbilicus that was termed a 'palpable umbilical ring'. In 18 of them this defect disappeared within four days, but in the other the ring did not close and a hernial sac with abdominal contents was palpable. This foal was considered to be the only foal to have a truly congenital umbilical hernia. Twelve foals developed an umbilical hernia between five and eight weeks of age. The prevalence of umbilical hernias was much higher than in other studies, possibly owing to the prospective nature of the study.

Abdominal Muscles↗
PubMed1994

[Displacement and resection of the ascending colon in the horse: a literature review on the basis of 2 cases].

A review of displacements and surgery of the large colon is given on the basis of two cases. A four-year-old Dutch Warmblood mare was referred, one week before foaling, for colic of twelve hours duration. At rectal palpation a large uterus was found, but no cause for the colic. Laparotomy revealed a colonic volvulus and resection of about 75% of the large colon was necessary. A dead foal was born five days postoperatively, but the mare recovered well. A nine year-old Dutch Warmblood stallion with a history of frequent colic had been treated for nephrosplenic entrapment three times. Resection of the left part of the colon was performed successfully to prevent another entrapment.

Animals↗
PubMed1994

A modified technique for implantation of polypropylene mesh for the repair of external abdominal hernias in horses: a review of 21 cases.

During a 3-year period 21 horses were surgically treated because of large abdominal wall defects. In each case the defect was bridged with a polypropylene mesh, which was placed on the outside of the hernial ring. This was in contrast with the technique for mesh herniorrhaphy generally described in human and veterinary literature, in which the mesh is always implanted on the inside of the hernial ring. One horse was destroyed on the first postoperative day because of postanaesthetic myelomalacia. Surgical repair as described was successful in 18 patients. Recurrence of herniation occurred in two horses. On re-herniorrhaphy a second and larger mesh was successfully implanted.

Animals↗