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Biomedical subjects

A T Fischer

Publications and source records attributed to A T Fischer.

At least 19 recordsLinked to original sources
PubMed2001

External skeletal fixation in the management of equine mandibular fractures: 16 cases (1988-1998).

Fifty-three cases of equine mandibular fractures were managed surgically from 1988-1998, of which 16 (30%) were repaired by external skeletal fixation (ESF). Three surgical methods were utilised: transmandibular 4.76 or 6.35 mm Steinmann pins incorporated into fibreglass casting material or nonsterile dental acrylic (methyl methacrylate - MMA) bars reinforced with steel; transmandibular 9.6 mm self-tapping threaded pins +/- 4.76 or 6.35 mm Steinmann pins incorporated into MMA bars reinforced with steel; and 4.5 mm or 5.5 mm ASIF cortical bone screws incorporated into MMA bars reinforced with steel or a ventral MMA splint. Fourteen horses were presented to the hospital for fixator removal at an average of 56.2 days. At removal, fractures were stable and occlusion of incisor and cheek teeth was considered adequate. Complications of the procedure occurred in 3 horses. Two horses with persistent drainage and ring sequestra from pin tracts required curettage 4 or 5 months after ESF removal. A third horse required replacement of the original fibreglass ESF with MMA bars to regain access to open, infected wounds. Another horse required removal of the second premolar at the time of fixator removal because the tooth root had been damaged in the original injury. ESF for the surgical management of mandibular fractures in horses has produced good results, with incisive and cheek tooth alignment reestablished in all horses. Horses that were managed via ESF had a rapid return to full feed and did not require any supplementation via nasogastric tube or oesophagostomy to maintain bodyweight or hydration status.

Animals↗
PubMed1999

Laparoscopically assisted resection of umbilical structures in foals.

A technique for laparoscopically assisted resection of umbilical structures in foals was developed. Eleven foals ranging from 8 to 42 days old underwent this procedure. Results of bacteriologic culture of umbilical structures were positive in 7 foals. Mean duration of anesthesia was 99 minutes, of which the initial 20 to 25 minutes were typically devoted to positioning and preparation of the foal for surgery. Major complications did not develop in any foal. Minor complications, such as slippage of the endoscopic ligating clip or laceration of the bladder during dissection, were dealt with successfully during the procedure. Potential benefits of use of laparoscopy (i.e., decreased postoperative morbidity, smaller incisions, and increased intraoperative access to structures) must be carefully weighed against the risks of increased duration of anesthesia. However, anesthetic-related complications were not observed in any foal.

Animals↗
PubMed1998

Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses.

Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses was evaluated retrospectively in 50 horses that underwent the procedure between 1991 and 1996. Sixty-one cryptorchid testes were removed by one of the following methods; the use of 1) an endoscoping stapling and transection device, 2) an endoscopic clipping device, 3) an endoscopic ligating loop. Monopolar electrosurgery was combined with these methods to facilitate coagulation and cutting of tissue. In 8 horses, 9 testes were retained between the internal and external inguinal rings. The inguinal testes were removed by cutting the internal inguinal ring and bringing the testis back into the abdomen for removal. No attempt was made to close the internal inguinal ring. The most frequently employed and most cost effective method for laparoscopic intra-abdominal removal of cryptorchid testes in this study was the combined use of an endoscopic ligating loop and monopolar electrosurgery. One intra-operative complication (perforation of the small intestine) occurred and was dealt with successfully. One horse developed a fever attributed to upper respiratory tract infection post operatively and was treated successfully with antibiotic. Intra-abdominal ligation and transection of cryptorchid testes is an effective method for cryptorchid castration. This technique minimises the loss of insufflation, allows inspection of the cut tissue for haemorrhage and offers secure closure of the abdominal wall preventing inguinal herniation and excellent visualisation of the cryptorchid testis.

Animals↗
PubMed1998

Thoracoscopy in the horse: diagnostic and therapeutic indications in 28 cases.

Thirty-two thoracoscopies were performed in 28 horses. Sixteen horses were affected with pleuropneumonia whereas 12 were affected with various other thoracic conditions. The indications for thoracoscopy was diagnostic in 19 cases, therapeutic in 11 cases and both diagnostic and therapeutic in 2 cases. Twenty-six thoracoscopies were done standing whereas 6 were performed under general anaesthesia. The specific procedures performed during thoracoscopy were exploratory only (7), biopsy of the lung and lymph nodes (10), drain placement into pleural effusions (2) and abscesses (5), exploration prior to thoracotomy (2), transection of pleural adhesions and decortication (1) and window pericardectomy (2). Diaphragmatic hernia repair (2) and partial pneumonectomy (1) were initiated thoracoscopically but conversion to thoracotomy was necessary for completion. Standing thoracoscopy was well tolerated in most horses. Transient exacerbation of pulmonary compromise evidenced by tachypnoea was readily alleviated by reinflation of the lung. Standing thoracoscopy provided good visualisation of the dorsal and lateral structures of the thorax. The ventral thoracic structures and the cranial ventral diaphragmatic surfaces of the lungs were best visualised in dorsal or lateral recumbency under general anaesthesia. Thoracoscopy is a safe and useful diagnostic and therapeutic tool in horses with thoracic diseases.

Anesthesia, General↗
PubMed1997

Advances in diagnostic techniques for horses with colic.

Recent advances in the use of abdominal ultrasound, endoscopy, laparoscopy, radiography, and peritoneal fluid analysis have contributed to the evaluation of horses with colic. Improved diagnostic capabilities allow earlier surgical intervention when necessary, and this should improve survival rates and the economic aspects of case management.

Abdomen↗
PubMed1996

Use of diagnostic ultrasonography in horses with signs of acute abdominal pain.

OBJECTIVE: To evaluate the use of abdominal ultrasonography as a diagnostic tool in horses with signs of colic. DESIGN: Prospective study. ANIMALS: 226 horses with signs of acute abdominal pain were compared to 20 clinical normal horses. PROCEDURE: The following were performed in horses with signs of colic: physical examination, CBC, abdominal fluid analysis, placement of a nasogastric tube to obtain gastric reflux, abdominal palpation per rectum, and ultrasonography of the abdomen. Results of ultrasonography were compared with the surgical, necropsy, or medical findings. RESULTS: Ultrasonography of horses with primary small-intestine lesions revealed images of small intestine with a wall thickness of 0.2 to 1.8 cm and a diameter of 3.6 to 13.5 cm without evidence of motility. Horses with peritonitis did have evidence of small-intestine motility on ultrasonography with a wall thickness of 0.5 to 1.3 cm and a diameter of 2 to 5.1 cm. Horses with primary large-colon lesions or small-colon impactions had small-intestine diameters on ultrasonographic evaluation of 3 to 7.1 cm. In these horses, small-intestine motility was detected. If abnormal small intestine that lacked motility was detected by ultrasonographic evaluation, the sensitivity, specificity, and positive and negative predictive values for small-intestine stragulation obstructions were 100%. Detection of distended or edematous small intestine by abdominal palpation per rectum provided a sensitivity of 50%, specificity of 98%, positive predictive value of 89%, and negative predictive value of 89% for small-intestine strangulation obstructions. CLINICAL IMPLICATIONS: The use of abdominal ultrasonography. In horses with signs of colic is accurate for detecting small-intestine strangulation obstructions.

Abdominal Pain↗
PubMed1995

Laparoscopic inguinal herniorrhaphy in two stallions.

Two mature stallions that were used for breeding purposes were admitted for evaluation of inguinal hernias. In 1 horse, the hernia was reduced per rectum by gentle traction applied to the intestine. In the other horse, the hernia was reduced by placing the horse in dorsal recumbency and applying external pressure over the scrotum. Both horses were observed for recurrence of the hernia. Seven days later, an elective laparoscopic technique for inguinal herniorrhaphy was performed on each horse, using polypropylene mesh. Complications did not develop, and both horses have successfully completed 2 full breeding seasons. Laparoscopic inguinal herniorrhaphy allows preservation of the testis on the affected side and precludes many complications associated with open surgical techniques used on inguinal rings.

Animals↗
PubMed1995

Retrograde contrast radiography of the distal portions of the intestinal tract in foals.

A technique for retrograde contrast radiography of the distal portions of the intestinal tract of foals was developed and then performed in 25 foals (1 to 30 days old) with colic. Retrograde contrast radiography was shown to be sensitive (100%) and specific (100%) for evaluating obstruction of the small colon or transverse colon. It was slightly less sensitive (86%) and specific (83%) for evaluation of the entire large colon, particularly in older foals. Retrograde contrast radiography provided increased diagnostic capability, compared with that for noncontrast radiography. Retrograde contrast radiography can provide valuable information when evaluating foals with colic and should be part of the diagnostic evaluation.

Animals↗
PubMed1995

Small intestinal herniation through the epiploic foramen: 53 cases (1987-1993).

The incidence of epiploic entrapment of the small intestine in horses undergoing celiotomy for colic was 5%. The condition was more prevalent in older (mean 9.81 years) gelding and Thoroughbred horses. Preoperative peritoneal protein level was a good prognostic indicator as it was significantly greater in the nonsurvivor (39.4 +/- 5.10) group than in the survivor group (26.6 +/- 14.0) (P<0.05). Abdominal ultrasonography allowed earlier diagnosis and surgical intervention in nonpainful cases with inconclusive rectal findings. Surgery was completed in 46 horses and 44 horses recovered from anaesthesia. Nine horses were either subjected to euthanasia in surgery (7 horses) or died in recovery (2 horses). Repeat laparotomies were pursued in 27% (12/44) of the horses. Seven horses (16%) showed post operative adynamic ileus which was the most common post operative complication. The incidence (6%) of adhesion formation was lower than previously reported. Other post operative complications included gastric ulceration, liver disease, diarrhoea and weight loss. Short and long term survival rates were 79% (35/44) and 70% (31/44) respectively. Improved rates were attributed to earlier referral and diagnosis and prompt surgical intervention. The aggressive use of repeat celiotomy and a more effective treatment of the endotoxic horse in the perioperative period contributed to survival.

Abdomen↗
PubMed1993

Transection of the pelvic flexure to reduce incarceration of the large colon through the epiploic foramen in a horse.

A 7-year-old Thoroughbred mare underwent exploratory celiotomy for diagnosis and treatment of colic. An irreducible herniation of the large colon through the epiploic foramen was found. To reduce the hernia, the pelvic flexure was transected and the ends of the large colon were closed. The intercolonic mesentery was divided, and unaffected left ventral colon was moved into the epiploic foramen, providing sufficient space so that affected left dorsal colon could be reduced. The affected left ventral colon was then reduced and the diseased portion of both colons was resected. The colons were resected. The colons were rejoined with an end-to-end anastomosis.

Anastomosis, Surgical↗
PubMed1992

Laparoscopic cryptorchidectomy in horses.

Laparoscopic cryptorchidectomy was successfully performed in 15 standing or recumbent horses. In 3 horses, owners believed that castrations had been performed, but the horses had retained stallion-like behavior. Successful removal of undescended testes in these horses stopped this behavior. Laparoscopy offered excellent visualization of the structures of the vaginal ring and facilitated removal of the abdominally located testis. The internal and external inguinal rings were not invaded, thus the chance of serious complications that may result during open cryptorchidectomy procedures was minimized.

Animals↗
PubMed1991

Standing laparoscopic surgery.

Laparoscopic procedures can replace many more invasive procedures. Guided visceral biopsy, cryptorchid castration, ovariectomy, and limited abdominal exploration may be done laparoscopically in the standing horse.

Animals↗
PubMed1989

Diagnostic and prognostic procedures for equine colic surgery.

Evaluation of the horse with colic has always been challenging since the patient's large size precludes many of the diagnostic imaging procedures commonly used in human medicine. Diagnostic methods such as radiography, laparoscopy, endoscopy, and peritoneal fluid analysis can serve to increase the accuracy of presurgical evaluation. Prognosis in individual cases can be best predicted by careful analysis of selected clinicopathological data, physical examination findings, and surgical biopsies. However, no predictive model is 100 per cent accurate, and clinicians must continue to rely on clinical evidence and instinct and to use these diagnostic and prognostic procedures only as guides for case management.

Abdomen, Acute↗
PubMed1988

Intensive care of the patient after abdominal surgery.

After surgical correction of the underlying abdominal disorder, careful postoperative care is the most important factor resulting in increased survival rates. Intensive care of the postoperative patient can be done practically and economically.

Abdomen, Acute↗
PubMed1987

Sagittal fractures of the third carpal bone in horses: 12 cases (1977-1985).

Third carpal sagittal fractures were found to be related to racing injuries in 10 of 12 horses. These fractures occurred most commonly on the medial aspect of the bone. A dorsoproximal-dorsodistal view of the carpus was required to visualize the fracture in all cases. Healing of the fracture required periods of rest of up to one year. Conservative management of these fractures resulted in return to function in 7 of 12 horses.

Animals↗