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Biomedical subjects

T S Stashak

Publications and source records attributed to T S Stashak.

At least 55 records · Page 3Linked to original sources

Effect of wound location and the use of topical collagen gel on exuberant granulation tissue formation and wound healing in the horse and pony.

Preformed collagen gel was topically applied to cutaneous wounds of the equine dorsal fetlock (thoracic limb) and metatarsal regions to evaluate the effect on exuberant granulation tissue production and wound healing. In 6 horses and 3 ponies (less than 140 cm high at the withers and less than 365 kg), 36 standardized cutaneous limb wounds were surgically induced (4 wounds/animal); 18 wounds were treated topically with collagen gel, and 18 wounds were not treated (controls). Collagen gel was initially applied to the wound at 0, 2, or 7 days after wound formation (groups 1, 2, and 3, respectively). Four measurements were regularly made: amount of wound contraction and the size of the granulation bed, epithelial covering, and total wound. Sequential skin and wound biopsies were evaluated histologically to assess wound healing. Using a computer, data were analyzed for differences in the 4 measurements between treated and control wounds, between fetlock wounds and metatarsal wounds, and among groups 1, 2, and 3. Analyses were performed on days 15 and 45 of wound healing and on the final day of healing. A significant difference (P greater than 0.05) in the production of exuberant granulation tissue, rate of epithelialization, or degree of wound contraction was not detected between the collagen-treated and control wounds. Total healing time and final scar size were similar. Wound healing patterns were significantly different (P less than 0.05) in the fetlock wounds and metatarsal wounds. All wounds enlarged up to day 15 with fetlock wounds enlarging significantly more than did the metatarsal wounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗

Morphologic features of the cervical intervertebral disks and adjacent vertebral bodies of horses.

The intervertebral disks and adjacent vertebral bodies of the 2nd to 7th cervical vertebrae from 17 horses (3 months to 19 years of age) were examined grossly and by light microscopy. In each specimen, the disk tissue was fibrocartilagenous centrally and became more fibrous peripherally, but without a distinct demarcation between the nucleus pulposus and anulus fibrosus. Demarcation between the anulus fibrosus and the dorsal longitudinal ligament was not apparent. With increasing age of the horses, cellularity of the central fibrocartilagenous portion of the disk decreased. The caudal end plates of the vertebrae had an increase in width and bone density with increasing age. In specimens from horses of all ages, the cranial end plate of the vertebrae had only a thin rim of dense bone. The cranial physis of each vertebral body was closed at 3 years of age, whereas the caudal physis of vertebral bodies was discontinuous in 6- to 9-year-old horses and was completely absent in horses greater than or equal to 12 years. Disruption of fibers of the anulus fibrosus by small amounts of fibro-cartilage was observed in disks from 5 horses. This change was similar to a Hansen type II disk prolapse.

Age Factors↗

Long-term results and complications of proximal interphalangeal arthrodesis in horses.

A retrospective study was made of 21 horses in which proximal interphalangeal arthrodesis had been performed. The right hindlimb was the most often affected (52%). Acute trauma was the most common reason for performing the surgery (62%). Follow-up data were obtained from the owners regarding return to serviceability . When available, follow-up radiographs and clinical examinations were reviewed. Of the 20 horses on which follow-up information was available, 16 were serviceable . Of the horses in which a hindlimb was arthrodesed , 86% were serviceable , whereas 67% of the horses affected in the forelimb were serviceable . An average of 1 year was required for return to serviceability . Follow-up radiography of forelimb cases revealed radiographic changes consistent with navicular disease, distal interphalangeal degenerative joint disease, and a bony exostosis off the dorsal surface of the third phalanx; however, these radiographic changes did not correlate well with the owner's assessment of serviceability . Follow-up clinical examination of forelimb cases revealed 2 horses in which the toe came off the ground during weight bearing.

Animals↗

Comparison of carbon fibre and nylon suture for repair of transected flexor tendons in the horse.

Carbon fibre-polylactic acid composites and monofilament non-absorbable suture material were compared for the repair of surgically transected superficial digital flexor tendons in 10 horses. All surgical wounds healed by first intention. The repaired tendons were enlarged, the carbon implanted tendons being larger than those sutured. The horses were killed at six, eight, 12,20 or 24 weeks. Greater fibrous thickening occurred in tendons repaired with carbon fibre, especially at 12 weeks postoperatively. Carbon fibre incited a greater histological response with macrophages, lymphocytes, plasma cells, eosinophils and fibroblasts. The fibrous tissue in the repair sites appeared to mature and the collagen to align at a similar rate irrespective of the method of repair. Only that tissue within and immediately surrounding the carbon bundles was immature at six months. There was minimal tendency for carbon filaments to separate and those that did were often surrounded by epithelioid macrophages forming a granuloma. Massive eosinophil concentrations were present between each granuloma. With each sequential test period the sutured tendons became increasingly stronger than the carbon implanted tendons. This may have been because of the immature core of tissue associated with the carbon bundles. No carbon particles were detected in draining lymph nodes.

Animals↗

Collection of bone grafts from the tuber coxae of the horse.

Autogenous bone grafts were obtained from the tuber coxae of 9 horses. The method used involved an oblique incision to expose the lateral aspect of the tuber coxae. The periosteum was incised and reflected in order to make a 5- by 2.5-cm opening in the lateral cortex for graft retrieval. The method provided good visualization, ample grafting material, and freedom from postsurgical complications.

Animals↗

Desmotomy of the accessory ligament of the superficial digital flexor tendon in the horse with use of a tenoscopic approach to the carpal sheath.

OBJECTIVE: To describe a tenoscopic approach to the carpal sheath for desmotomy of the accessory ligament of the superficial digital flexor tendon. STUDY DESIGN: The surgical procedure was developed with use of normal forelimbs from equine cadavers and experimental horses. ANIMALS OR SAMPLE POPULATION: Twelve equine cadaveric forelimbs, 4 forelimbs from 2 horses anesthetized for terminal surgical laboratories, and 10 forelimbs from five experimental horses were used. METHODS: The limbs were positioned lateral side up with the carpus slightly flexed. After distention of the carpal sheath, a portal was made approximately 2 cm proximal to the distal radial physis for arthroscope insertion. An instrument portal was made approximately 0.2 cm proximal to the distal radial physis. After flexion of the limb to 90 degrees, the accessory ligament of the superficial digital flexor tendon was palpated and desmotomy was performed. Cadaveric limbs were dissected to confirm complete desmotomy. Experimental horses were monitored for short- (perioperative) and long- (4 weeks) term postoperative complications. RESULTS: A tenoscopic approach to the carpal sheath provided adequate surgical access to the accessory ligament of the superficial digital flexor tendon for desmotomy. Most of the accessory ligament of the superficial digital flexor tendon could be easily seen within the sheath, except for the proximal 2 cm that could be readily palpated and subsequently transected. Important technical considerations were location of the arthroscope portal, adequate sheath distention, limb flexion to 90 degrees, and desmotomy location. It was beneficial, but apparently not essential, to avoid the proximal perforating vessel. Postoperatively, some horses had swelling but were not lame and had normal range of motion of the carpus. CONCLUSIONS: Desmotomy of the accessory ligament of the superficial digital flexor tendon could be performed by using a lateral tenoscopic approach to the carpal sheath. CLINICAL RELEVANCE: Desmotomy of the accessory ligament of the superficial digital flexor tendon by using a tenoscopic approach to the carpal sheath is an alternative technique to the medial incisional approach.

Animals↗

Idiopathic focal eosinophilic enteritis associated with small intestinal obstruction in 6 horses.

OBJECTIVE: To report the history, clinical findings, and outcome of horses with idiopathic focal eosinophilic enteritis associated with acute small intestinal obstruction. STUDY DESIGN: Retrospective study. ANIMALS: Six horses with idiopathic focal eosinophilic enteritis. METHODS: Retrospective review of medical records of horses with idiopathic focal eosinophilic enteritis, with acute abdominal pain and small intestinal obstruction, associated with a focal region of eosinophilic enteritis of unknown cause. Information retrieved from the medical records included signalment, physical examination, laboratory findings, surgical procedure, histologic diagnosis, and postoperative management. Outcome was determined by telephone communication with owners. RESULTS: Six horses met the selection criteria. Horses had persistent pain, distended small intestine, and nasogastric reflux. Idiopathic focal eosinophilic enteritis lesions associated with a small intestinal obstruction were treated surgically by intestinal resection and anastomosis or wedge resection. There were no observed complications associated with extension of the disease from the lesion site. Five horses were alive at follow-up 5 to 60 months after surgery. CONCLUSIONS: Although the cause of these focal eosinophilic enteritis lesions is unknown, the long-term outcome after lesion resection was favorable. CLINICAL RELEVANCE: Small intestinal obstruction associated with a focal eosinophilic enteritis lesion may be a cause of acute abdominal pain in horses. Horses apparently have a good prognosis after lesion resection.

Animals↗

Experimental large colon resection at the cecocolic ligament in the horse.

Ten normal horses had approximately 95% of the length of the large colon resected with a side-to-side anastomosis between right ventral and right dorsal colon performed with surgical stapling equipment. Four horses died shortly after surgery of colitis (1 horse) or failure of the TA 90 transection staple line (3 horses). Another horse died 4 months after surgery from disseminated streptococcal infection but had recovered well from the colon resection. Five horses survived long term (18 months) with no clinical evidence of adverse effects of the resection. Surviving horses had weight loss and soft fecal consistency for 3 to 12 weeks after surgery but returned to preoperative values within 12 months. At a second surgery 1 year later (5 horses) or at necropsy 4 months later (1 horse), fibrous omental adhesions were present over the transection staple line in four horses and over the anastomotic staple line in two horses. Omental adhesions to the everted staple line were moderate but not associated with any clinical sequellae. An incisional hernia was present in one horse. The anastomotic stomata measured between 8 and 9 cm, which was 60% of the size of the original surgically created stomata. Failure of the transection staple line occurred in the first three of five horses in which the procedure was attempted due to improper configuration of the staples or crushing of the tissue between the staples. Experience corrected this complication.

Anastomosis, Surgical↗

Arthroscopic surgery for the treatment of osteochondrosis in the equine shoulder joint.

Osteochondritis dissecans (OCD) and subchondral cyst-like lesions in 13 shoulders of 11 horses were treated arthroscopically by curettage and lavage. Lameness decreased in all 11 horses. Nine horses were sound, five of them athletically sound, after 5 to 20 months. Complications included the development of subchondral cyst-like lesions and signs of degenerative joint disease. Arthroscopic surgery of the equine shoulder can be done through two portals, one for the arthroscope and one for an instrument. A few hand instruments such as a probe, Ferris-Smith rongeurs, and small, large, and right-angled curettes are needed to debride most lesions. Motorized equipment can expedite the process.

Animals↗

Incisional hernias in the horse. Incidence and predisposing factors.

Medical records of 210 horses that survived ventral midline celiotomy for at least 4 months were examined and owners were queried to determine factors contributing to incisional hernia formation. The incidence rate of incisional hernias within 4 months was 16%. Factors significantly associated with occurrence of incisional hernias were incisional drainage, closure of the linea alba with chromic gut suture material, previous midline celiotomy, excessive incisional edema, castrated male sex, postoperative leukopenia, and postoperative pain (colic). Factors not significantly associated with occurrence of incisional hernias were suture pattern used for linea alba closure, concurrent enterotomy or intestinal resection, postoperative bandage or stent, postoperative fever, hypoproteinemia, diarrhea, respiratory disease (coughing), and peritonitis. Hernias developed in horses within 12 weeks of surgery, with the earliest hernia recognized at week 2. Of 30 horses for which information was available, only one hernia developed in 24 (80%) and two or more hernias developed in 6 (20%) along the incision. Multiple hernias tended to be smaller than single hernias.

Abdominal Muscles↗

Mechanical properties of four suture patterns for transected equine tendon repair.

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.

Analysis of Variance↗

A comparison of repair methods for gap healing in equine flexor tendon.

In nine horses (18 forelimbs), a 3 cm section of superficial digital flexor tendon was removed and the tendons were repaired with immobilization for 6 weeks and (1) no suture (n = 6); (2) a double locking loop tenorrhaphy with carbon fiber (n = 6); or (3) a double locking loop tenorrhaphy with size 2 nylon suture (n = 6). Clinical assessment, gross evaluation, morphometry, histology, and mechanical testing were performed on two limbs from each treatment group at weeks 6, 12, and 24. At weeks 6 and 12, the unsutured tissue was less mature than the tissue sutured with nylon. By week 24, the carbon fiber repair had breaking stress (mean, 12.5 M Pa) similar to the unsutured repair (mean, 10.6 M Pa). There was necrosis and a granulomatous foreign body reaction around the carbon fiber. The nylon suture repair had significantly greater strength per unit area (mean breaking stress, 20.4 M Pa) because of a smaller area of repair tissue in the gap (mean, 3.6 cm2). At week 24, the nylon suture repair tissue was the most mature with the least inflammation of the three repair methods. A nylon double locking loop suture was the preferred method for equine flexor tenorrhaphy of a tendon gap because of greater breaking stress, histologic maturity, biocompatibility, and the adequate functional and cosmetic outcome.

Animals↗

Bacterial culturing of ventral median celiotomies for prediction of postoperative incisional complications in horses.

OBJECTIVE: The purpose of this study was to determine whether detection of bacterial contamination of ventral midline incisions was predictive of postoperative incisional complications in horses undergoing exploratory celiotomy for colic. STUDY DESIGN: Prospective study. ANIMAL OR SAMPLE POPULATION: Horses that had ventral median celiotomies for colic at Colorado State University between May 1, 1991 and April 30, 1993 were studied prospectively. Complete information was obtained on 66 horses. METHODS: Bacterial cultures were obtained from ventral midline incisions at surgery. Information regarding the type of surgery performed (celiotomy vs celiotomy plus enterotomy or enterectomy), preoperative total nucleated cells and presence of a left shift, postoperative fever (> 38.5 degrees C), incisional drainage, incisional herniation, and outcome were obtained from medical records. Additional information concerning incisional drainage, herniation, and survival was obtained at a minimum of 18 months after surgery. RESULTS: Examination of odds ratio (ORs) and confidence intervals (CIs) revealed that a celiotomy plus enterotomy or enterectomy was positively, but not significantly, associated (OR > 1) with positive culture results, presence of incisional drainage and incisional herniation. A significant association between incisional drainage and hernia formation was found; odds of incisional herniation were 62.5 times greater in horses that had incisional drainage. Incisional drainage and herniation were negatively associated with patient survival. The later association was significant (OR = 0.18, P = .04). CONCLUSIONS: This study indicated that detection of bacterial contamination at incisional closure by the swab culture technique was not beneficial in the prediction of postoperative incisional problems in horses undergoing colic surgery. Incisional drainage or infection appeared to be associated with hernia formation. CLINICAL RELEVANCE: Immediate treatment of incisional drainage or method to prevent incisional infections may decrease hernia formation.

Abdomen↗