A secure Aberdeen knot: in vitro assessment of knot security in plasma and fat

O bjectives : To determine the minimum number of throws/turns to form a secure Aberdeen knot and the maximum ear slippage for these knots using three metric polydioxanone coated in fat or plasma. To compare plasma and novel canine liquefied fat as suture coating mediums for in vitro knot security testing.
M ethods : Throws/turns were incrementally added until a secure knot was found for plasma and fat. Knots were tensioned until failure and remaining ear length measured. A secure knot was defined as ear slippage 3 mm or less in 20 consecutively tested knots. Ear slippages were statistically analysed.
R esults : Minimum secure configuration was a 3+1 knot in plasma and fat, and its ear slipped a maximum of 2 mm in plasma and 2·5 mm in fat. A secure 4+1 knot had a maximum ear slippage of 0·5 mm, which was significantly less than that of the 3+1 knot (P<0·0001). Fat coating suture significantly decreases in vitro knot security compared with plasma (P=0·0035).
C linical S ignificance : The novel fat coating medium should be considered when testing in vitro knot security as it simulates a clinical knot tying environment. A 4+1 Aberdeen knot with a 3 mm ear is recommended to tie a secure Aberdeen knot in any body fluid environment.     

Biomechanical Comparison of Six Suture Configurations Using a Large Diameter Polyester Prosthesis in the Muscular Process of the Equine Arytenoid Cartilage

Objective— To compare biomechanical properties of 6 suture configurations using a large diameter polyester prosthesis in the muscular process (MP) of the arytenoid cartilage and to determine failure mode.
Study Design— Experimental study.
Sample Population— Cadaveric equine larynges (n=121).
Methods— Suture configurations (4 single, 2 double) were inserted, and then constructs were tested in a single-cycle to failure at a 100 mm/min distraction. Load deformation curves were generated to assess the biomechanical properties of each construct. A 1-way ANOVA was used to compare the mean differences in construct failure force, cricoarytenoid joint (CAJ) disarticulation force, and energy stored at failure. A 2-sample t-test was used to compare single versus double suture patterns and a Fisher's exact test was used to compare failure mode.
Results— Both construct and CAJ failure force were significantly greater ( P <.05) for double suture patterns compared with single suture patterns; however, there were no significant differences in energy stored at construct failure. Failure at the MP accounted for ≥50% of construct failures for 3 of the single suture patterns and 1 of the double suture patterns tested. The remaining 2 patterns had an increased frequency of clamp failures as well as failure of the cricoid cartilage.
Conclusions— Sutures that sufficiently engage the spine of the MP alone or in conjunction with a second suture were found to be biomechanically superior.
Clinical Relevance— Engaging the spine of the MP appears to result in the most biomechanically sound laryngeal construct.     

In vitro evaluation of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System

OBJECTIVE: To evaluate the mechanical properties of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System. STUDY DESIGN: In vitro mechanical evaluation. SAMPLE POPULATION: Loop constructs of 18, 27, and 36 kilogram test (kgt) nylon leader line (NLL) secured with Securos crimp-clamps (SCC, n=40 per NLL test weight) or by a clamped square knot (CSK; n=40/NLL test weight). METHODS: The 36 kg SCC were used for the 27 and 36 kgt NLL, and 18 kg SCC were used for the 18 kgt NLL. Loop constructs were mounted on a material testing machine, and distracted at 500 mm/min for static tests, and for cyclic tests at 500 mm/min to a distraction limit of 6 mm (18 kgt) or 7.5 mm (27 and 36 kgt) for 49 cycles, until failure. Constructs were tested at 20 degrees C except for 1 group of 27 kgt CSK loops tested at 40 degrees C. Load at failure, elongation, and stiffness was recorded and compared between groups under static or cyclic testing conditions. RESULTS: All 27 and 36 kgt loops failed by disruption of NLL contained within the knot or crimp-clamp, whereas 18 kgt SCC loops failed by the NLL pulling through the crimp-clamp. The 18 kg SCC loops had considerable variability in ultimate load and elongation (coefficient of variation 29.6% and 18.3%, respectively). There was no significant difference in elongation between 27.3 kgt CSK loops tested at 20 degrees C and 40 degrees C. Generally, in both static and cyclic testing, SCC constructs formed with 27.3 or 36.4 kgt NLL performed as well or better than CSK constructs, resulting in loops that were strong, underwent minimal elongation, and had high stiffness. CONCLUSION: The results support use of the 36 kg Securos system but not the 18 kg Securos system (with the clamp and crimping device used). The significantly lower load required for failure, slippage through the clamp, and substantial variability suggested that the crimp tube diameter or the crimping device tested may be inappropriate for use with 18 kgt NLL. CLINICAL RELEVANCE: Surgeons should be aware that crimp-clamp design is important in controlling suture slippage or breakage within the clamp, and that novel systems should undergo mechanical testing with the size suture material they are intended to secure before clinical use.     

In Vitro Biomechanical Comparison of Polypropylene Mesh, Modified Three-Loop Pulley Suture Pattern, and a Combination for Repair of Distal Canine Achilles' Tendon Injuries

Objective— To compare mechanical stability between a novel polypropylene mesh repair (Mesh), a modified 3-loop pulley suture (Suture), and a combination of the techniques (Suture+Mesh) for the repair of distal canine Achilles' tendon ruptures.
Study Design— In vitro mechanical evaluation.
Sample Population— Cadaveric canine Achilles' tendon/calcaneus units (n=34).
Methods— Constructs were loaded under tension to failure in a materials testing machine with synchronized kinematic analysis. Ultimate load to failure, global construct stiffness, and force required to reach 1 and 3 mm gap formation was recorded.
Results— Ultimate load to failure was greatest for the Suture+Mesh group and lowest for the Suture group. The Suture+Mesh technique afforded a significantly greater global stiffness than the Suture or Mesh treatments. Force to generate 1 and 3 mm gap formation was greatest with the Suture group.
Conclusions— The Suture+Mesh group had the highest ultimate load to failure and afforded the greatest global stiffness though it had no added benefit to resist local gap formation at the repair.
Clinical Relevance— Achilles' ruptures repaired with suture can be augmented with mesh to increase the ultimate load to failure, but as currently tested, there was a decrease in resistance to gap formation At this time we cannot recommend Mesh or the Suture+Mesh techniques without further testing.     

Breakage of two silicone endotracheal tubes during extubation

Silicone endotracheal tubes broke during tracheal extubation of two dogs after uneventful anaesthesia. The remaining pieces were removed via endoscopy, and both dogs recovered with no further problems. A third silicone endotracheal tube broke while checking for cracks prior to its use. Biofilm formation on the surface of the endotracheal tube is thought to be the main cause of the breakage. Destruction of the biofilm is difficult, therefore exhaustive cleaning with detergents followed by vigorous brushing is recommended to break the interaction between the silicone surface and the biofilm. It is suggested that careful attention is paid to how tubes are cleaned and dried (in a hanging position), and that they are checked carefully for cracks prior to each use.     

Comparison of Three Methods of Ulnar Fixation in Horses

Objective- This study compares the mechanical properties of three methods of equine ulnar fixation: dynamic compression plating, pins and wires tension band, and a prototype grip system.
Study Design- The mechanical properties of dynamic compression plating, pins and wires tension band, and a prototype grip system repair of equine ulnar fractures were evaluated in a cadaveric osteotomy model.
Animals or Sample Population- Fifteen pairs of the radius and ulna from equine cadavers.
Methods- The three repair techniques were evaluated to mimic the pull of the triceps brachii muscle in single cycle to failure and in cyclic fatigue loading. Single cycle results were evaluated as the axial and angular displacement. Cyclic fatigue results were evaluated as the number of cycles to failure.
Results- Dynamic compression plate fixation and pins and wires tension band had significantly less axial displacement of the proximal fragment than the grip system ( P <.05). No significant difference in angular rotation of the proximal fragment was present between the three techniques. Dynamic compression plating had significantly greater fatigue resistance than the grip system ( P <.05). Cyclic failure was characterized by screw loosening or breakage and wire breakage.
Conclusions- Dynamic compression plates were better than the other techniques at maintaining compression of a transverse ulnar osteotomy at the level of the anconeal process just proximal to the trochlear notch.
Clinical Relevance- Knowledge of fixation technique mechanical properties is essential for surgeons to select the proper method of fracture repair.     

Risk factors for tibial tuberosity fracture after tibial plateau leveling osteotomy in dogs

Objective— To evaluate factors that predispose to tibial tuberosity (TT) fracture after tibial plateau leveling osteotomy (TPLO) in dogs.
Study Design— Retrospective study.
Animals— Dogs (n=182) with cranial cruciate ligament (CCL) rupture undergoing 213 TPLO surgeries.
Methods— Medical records and radiographs of 2 groups of dogs that had TPLO surgery (2000–2001, 2004–2005) were evaluated to determine the effect of operative technique and surgeon experience on TT fracture.
Results— TT fracture was diagnosed in 8 dogs (9 TPLO, 4.2% of surgical procedures). Four fractures occurred after unilateral TPLO in 167 dogs (2.4%), 4 fractures occurred after simultaneous bilateral TPLO in 5 dogs (40%), and 1 fracture occurred after staged bilateral TPLO in 36 dogs (2.8%). Simultaneous bilateral TPLO resulted in a 12.4 times higher odds of TT fracture versus unilateral TPLO ( P =.046). The mean absolute thickness of the TT after TPLO was less in dogs sustaining TT fractures (7.2 ± 2.2 mm) than those that did not (10.8 ± 2.7 mm, P <.0001). The odds of fracture decreased by 37% when the absolute TT width postosteotomy increased by 1 mm ( P <.0001). An increase in tibial plateau angle at follow-up versus immediately postoperative was associated with TT fracture ( P =.025). Surgeon experience was not associated with TT fracture.
Conclusion— A combination of surgical decision-making and surgical technique play a role in the occurrence of TT fracture after TPLO. Simultaneous bilateral TPLO was associated with a high percentage of TT fracture.
Clinical Relevance— Careful planning of osteotomy positioning is advised while performing TPLO surgery.     

Biomechanical Comparison of Four Soft Tissue Replacement Materials: An In Vitro Evaluation of Single and Multilaminate Porcine Small Intestinal Submucosa, Canine Fascia Lata, and Polypropylene Mesh

Objective— To compare mechanical performance of 4 soft tissue replacement materials.
Study Design— Experimental.
Sample Population— Polypropylene mesh (PM), single-layer porcine small intestinal submucosa (SIS), multilaminate (4-layer) porcine small intestinal submucosa (MLSIS), and canine fascia lata (FL).
Methods— The mechanical properties of each material were determined by testing to failure on a materials testing machine. Samples of each material (n=10) were tested in 3 different modes: resistance to suture pullout, tensile testing, and push-through testing. PM was tested both parallel (PMa) to and perpendicular (PMb) to its longitudinal cord orientation. SIS and FL were similarly tested in 2 orthogonal directions.
Results— With some exceptions, the following generalizations can be made regarding the mechanical performance of the materials tested:
Suture pullout— FL>PMa=PMb>MLSIS>SIS ( P ≤.04).
Tensile testing —FL>PMa>PMb>MLSIS>SIS ( P ≤.02).
Push-through testing— FL>PM>MLSIS>SIS ( P ≤.003).
Conclusions— PM accommodated a significantly higher load and energy to yield when its longitudinal cords were oriented parallel with the tension axis (PMa). FL performed similarly to the PM, with the exception of limited elongation in tension. MLSIS had biomechanical characteristics that were inferior to FL and PM but superior to SIS.
Clinical Relevance— PM's orientation may need to be considered when used clinically. FL is a biomechanically suitable soft tissue replacement material but its use may be limited by currently available sizes. SIS cannot be recommended in high-strain environments.     

Controlled release of estradiol-17β and bisphenol A from a silicone tube for long-term administration in mice

Silicone tubes filled with estradiol‐17β (E2) or the xenestrogen, bisphenol A (BPA) were covered with a polyethylene tube and implanted into mice subcutaneously. The releasing patterns from the tube in vivo were obtained from the volume of estrogen remaining in the tube by measurement with high performance lipid chromatography. E2 in glycerol was released in a few days from a silicone tube, which was not covered with a polyethylene tube (Type A). However, E2 in sesame oil was released very slowly from the silicone tube covered with a polyethylene tube (Type B) and approximately 10% of E2 remained in the tube at 56 days after implantation into the mice. The mean linear regression equation for E2 was Y = 70.967 ? 1.2271X (R² = 0.9268) and the quadratic regression equation was Y = 77.97 ? 2.2773X + 0.0194 × 2 (R² = 0.9864). The remainder rate curves of E2 and BPA were not significantly different throughout the experimental period of 56 days. The Type B tube in the present experiment might be useful for long‐term administration of estrogens.     

Analysis of suture anchor eyelet position on suture failure load

Objective: To compare mechanical performance of 2 orientations of the 5 mm Corkscrew^® suture anchor with #5 Fiberwire^®. Study Design: In vitro biomechanical study. Sample Population: Suture anchor–suture constructs (n=40). Methods: Acute and cyclic tensile loads were applied to suture threaded through eyelets of 40 anchors perpendicular to the long axis of the anchor. Eyelets were positioned so that the suture pull was in line with (anchor rotation angle of 0° [ARA 0]) or 90° (ARA 90) to the eyelet plane. Load at failure, stiffness, and cycles to failure were determined. Results: All constructs failed by suture breakage at the eyelet. Mean load at failure was significantly higher in the ARA 90 group (634±93 N) compared with the ARA 0 group (495±52 N; P=.0015). No significant difference was found between groups for mean number of cycles to failure (270±177 versus 178±109; P=.2166) and stiffness (50±4 versus 48±5 N/mm; P=.3141). Conclusions: The Corkscrew^® 5 mm suture anchor with Fiberwire^® suture fails via suture breakage at the eyelet under higher acute loads if the suture is loaded at an angle of 90° compared with 0° with respect to the plane of the eyelet.     

Intracorporeal suture closure of the internal inguinal and vaginal rings in foals and horses

Objective— To report a technique for repair or prevention of inguinal hernia in horses using intracorporeal suture closure of the internal inguinal and vaginal rings.
Study Design— Case series.
Animals— Foals (n=6) and geldings (n=2).
Methods— After selection of a peri-umbilical telescope portal, instrument portals were made unilaterally or bilaterally, as needed. Herniated viscera was reduced, castration (foals) or spermatic cord remnant transection at the internal inguinal ring (adults) performed, and then simple interrupted intracorporeal sutures of synthetic absorbable suture material were used to close the internal inguinal and vaginal rings.
Results— There was no recurrence of inguinal hernia. Postoperative morbidity was minimal and cosmetic outcome was comparable to that achieved with conventional, open techniques.
Conclusion— Laparoscopic, primary closure of the internal inguinal ring by use of intracorporeal sutures provides a secure barrier to herniation and costs considerably less than using endoscopic staples.
Clinical Relevance— Laparoscopic suture closure of the internal inguinal and vaginal rings provides safe and effective repair of inguinal hernia in horses.     

Biomechanical analysis of suture anchors and suture materials in the canine femur

Objective— Biomechanical analysis of acute load to failure (ALF) of 3 veterinary and 1 human suture anchor and cyclic load to failure with two suture material/suture anchor constructs in canine femoral condyles.
Study Design— Biomechanical in vitro study.
Sample Population— Cadaveric femora from 20–30 kg dogs.
Methods— Three veterinary and 1 human suture anchor were placed in the cranial and caudal aspects of the femoral condyle and subjected to 0° ALF. Anchors were loaded with 5 USP Fiberwire or 27 kg test nylon leader line (NLL) and subjected to 90° cyclic testing for 10,000 cycles followed by ALF at 90°.
Results— No significant difference in ALF for any anchor type was detected in the cranial aspect of the femoral condyle; however all veterinary anchors had higher ALF in the caudal aspect of the femoral condyle. In cyclic testing, the constructs in descending order (most cycles to least) were: (1) FlexiTwist/NLL, (2) Securos/Fiberwire, Securos/NLL, (3) IMEX/Fiberwire, IMEX/NLL, and (4) FlexiTwist/Fiberwire, Fastin/Fiberwire. Fiberwire was significantly stronger than NLL in post-cycling ALF testing.
Conclusions— Veterinary anchors had higher ALF in the caudal versus cranial aspect of the femoral condyle. Except for the FlexiTwist in which NLL performed better, Fiberwire and NLL both had similar cyclic performance with each veterinary anchor type. The veterinary anchors exceeded the human anchor in ALF and cycles to failure.
Clinical Relevance— The tested veterinary suture anchors with Fiberwire or NLL may be used in the femoral condyle, preferably in the caudal aspect, and should withstand estimated loading conditions in appropriately confined postoperative canine patients.     

Factors associated with outcome in foals with neonatal isoerythrolysis (72 cases, 1988-2003)

Background: Neonatal foals with isoerythrolysis (NI) often die, but the risk factors for death have not been identified.
Objectives: To identify factors associated with outcome in foals with NI and to identify factors associated with death from liver failure or kernicterus in the same population.
Animals: Seventy-two foals with NI examined at referral institutions.
Methods: Retrospective case series. Information on signalment, clinical examination findings, laboratory testing, treatment, complications, outcome, and necropsy results were obtained.
Results: The overall survival rate was 75% (54 of 72). Liver failure (n = 7), kernicterus (n = 6), and complications related to bacterial sepsis (n = 3) were the 3 most common reasons for death or euthanasia. The number of transfusions with blood products was the factor most strongly associated with nonsurvival in a multivariate logistic regression model. The odds of liver failure developing in foals receiving a total volume of blood products ≥ 4.0 L were 19.5 (95% confidence intervals [CI]: 2.13–178) times higher than that of foals receiving a lower volume ( P = .009). The odds of kernicterus developing in foals with a total bilirubin ≥ 27.0 mg/dL were 17.0 (95% CI: 1.77–165) times higher than that of foals with a lower total bilirubin ( P = .014).
Conclusions and Clinical Importance: Development of liver failure, kernicterus, and complications related to bacterial sepsis are the most common causes of death in foals with NI. Foals administered a large volume of blood products are at greater risk for developing liver failure.     

Minimally Invasive Inguinal Approach for Tube Cystostomy

Objective— To report a technique for tube cystostomy placement via a minimally invasive inguinal approach and outcome in 9 dogs and 6 cats with urinary tract obstruction or detrusor atony.
Study Design— Case series.
Animals— Dogs (n=9) and cats (6).
Methods— Medical records (January 2004–January 2008) of dogs and cats that had tube cystostomy via an inguinal approach were reviewed. Retrieved data included signalment, diagnosis, surgical technique, and complications. Access to the bladder was through a muscle splitting approach in the inguinal region with the cystostomy tube placed through a skin incision made several centimeters proximal to this incision and secured in the bladder by a purse string suture. Cystopexy during closure of the muscle layers ensured secure closure and minimized the likelihood of uroabdomen if tube dislodgment occurred.
Results— Cystostomy tubes were placed in 5 cats as an emergency procedure for treatment of acute urinary tract obstruction or urethral rupture, and as an elective procedure in 9 dogs and 1 cat. No complications occurred during cystostomy tube placement. Postprocedural complications were minor (peristomal irritation in 2 dogs with latex catheters, catheter laceration, premature removal) and only occurred when tubes were retained for >4 weeks. Urinary tract infection at catheter removal in 6 dogs resolved with antibiotic administration.
Conclusions— An inguinal approach for cystostomy tube placement facilitated rapid catheter placement into the bladder with minimal soft tissue dissection. Cystopexy during abdominal wall closure provided peritoneal protection should premature dislodgement of the cystostomy tube occur.
Clinical Relevance— An inguinal approach should be considered for rapid tube cystostomy particularly in metabolically compromised animals.     

Arthrodesis of the Proximal Interphalangeal Joint in the Horse: A Cyclic Biomechanical Comparison of Two and Three Parallel Cortical Screws Inserted in Lag Fashion

Objective— To compare the biomechanical cyclic fatigue properties of 2 and 3 parallel transarticular 5.5 mm cortical screws used in arthrodesis of the proximal interphalangeal (PIP) joint.
Study Design— Randomized block design, for horse, fixation method (2 versus three 5.5 mm cortical screws), side (right, left) and end (front, hind) in cadaveric equine limbs.
Sample Population— Cadaveric adult equine fore- and hindlimbs (n=5 pairs each).
Methods— Two parallel 5.5 mm cortical screws were inserted in lag fashion, transarticularly through the PIP joint in 1 limb of a pair, and in the contralateral limb, three 5.5 mm cortical screws were inserted in similar fashion. Constructs were then tested in 3-point bending in a dorsal-to-palmar (plantar) direction using a materials testing machine using a cyclic load of −500 to −3500 N at a rate of 6 Hz.
Results— There was no significant difference in displacement at failure, force at failure or number of cycles between limbs. Forelimb constructs tended to fail at a greater mean displacement than hindlimb constructs but this difference was not significant ( P =.06). There was no statistical difference in any tested biomechanical variable between left- and right-sided limbs.
Conclusions— There was no significant difference in the number of cycles to failure for the 2 methods tested.
Clinical Relevance— Two 5.5 mm cortical screws inserted in parallel for PIP joint arthrodesis is surgically simpler, results in comparable biomechanical performance in the current model and should perform as well as three 5.5 mm screws under cyclic fatigue conditions.     

海兰灰蛋鸡患输卵管囊肿对屠宰性能、器官指数、血清生化指标及组织病理学的影响

本试验旨在研究海兰灰蛋鸡患输卵管囊肿对屠宰性能、器官指数、血清生化指标及组织病理学的影响.选取同一饲养环境下的54周龄海兰灰蛋鸡16只,分为对照组(CTR,n=9)和输卵管囊肿组(CFT,n=7)进行屠宰并采集血清样品,测定蛋鸡屠宰性能、器官指数和血清生化等指标.结果表明:1)输卵管囊肿组蛋鸡的活重和屠体重较对照组极显...     

鸡IGF-Ⅰ基因单核苷酸多态性及其与屠体性状关系的研究

本研究采用PCR-RFLP技术,对438只黄羽矮小型肉鸡的胰岛素样生长因子-Ⅰ基因(IGF-Ⅰ)的5′端进行遗传多态性研究,发现该区域的PCR扩增产物经Hinf Ⅰ酶切后出现GG、GT和TT 3种基因型。经χ2检验,群体在该位点上处于Hardy-Weinberg平衡状态(P>0.05)。方差分析结果显示,性别对9个性状(活体重、屠体重、皮脂厚、半净膛、全净膛、胸肌重、腿肌重、腹脂重、腹脂率)有极显著影响(P<0.01),对肌间脂肪含量有显著影响(P<0.05)。家系效应在8个性状上(活体重、屠体重、半净膛、全净膛、胸肌重、腿肌重、腹脂重、腹脂率)达到极显著水平(P<0.01);而基因型效应只在腹脂率上达到显著水平(P<0.05),腹脂重没有达到显著水平(P=0.0669)。不同基因型的最小二乘均值间多重比较结果发现,TT型的腹脂重和腹脂率均显著低于GT型(P<0.05),而GG型和GT、TT型的差异不显著(P>0.05)。     

Biomechanical evaluation of suture pullout from canine arytenoid cartilages: effects of hole diameter, suture configuration, suture size, and distraction rate

OBJECTIVE: To evaluate the mechanical properties of canine arytenoid cartilage-suture constructs. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Eighty canine cadaveric larynges. METHODS: Arytenoid cartilage-suture constructs were loaded to failure on a materials testing machine. The effect of hole size, suture configuration, suture size, and rate of distraction on load at failure, displacement at failure, energy to failure, and construct stiffness were evaluated. Polypropylene sutures were used exclusively. Specific variables evaluated were: (1) hole size-SH needle, 22, 20, and 18 ga hypodermic needles; (2) suture configurations-single dorsal and ventral articular sutures, double sutures, horizontal mattress, locking loop, and single non-articular sutures; (3) suture size-1, 0, 2-0, and 3-0; and (4) distraction rate-0.83 and 36.66 mm/s. RESULTS: Hole size had no effect on any biomechanical variable. Double suture and horizontal mattress configurations had the highest median load and energy at failure. Single dorsal suture configurations that did not include the arcuate crest had the lowest median load at failure. Larger suture sizes tended to result in stiffer constructs. Cartilage-suture constructs behaved in a viscoelastic manner where load at failure, energy at failure, and stiffness increased when distraction rate was increased, whereas displacement at failure did not. Most constructs failed by suture pullout regardless of distraction rate, although 50% of horizontal mattress configurations failed by avulsion of the muscular process. CONCLUSION: Suture and hole sizes appear to have few effects on the biomechanical performance of arytenoid-suture constructs. Double-suture and horizontal mattress suture patterns had the best overall mechanical properties for arytenoid lateralization. Single-suture techniques, which do not incorporate the arcuate crest, were biomechanically inferior. CLINICAL RELEVANCE: Cumbersome large-diameter sutures offer no advantage over smaller sutures when performing arytenoid lateralization. The cross-sectional geometry of the muscular process should be taken into account when placing sutures in the arytenoid cartilages. Single-suture techniques that do not incorporate the arcuate crest should be avoided.     

Cross-Sectional Imaging Characteristics of Pituitary Adenomas, Invasive Adenomas and Adenocarcinomas in Dogs: 33 Cases (1988–2006)

Background: Pituitary tumors in dogs can be adenomas, invasive adenomas, or adenocarcinomas. In people, invasive adenomas and pituitary adenocarcinomas carry a worse prognosis than adenomas.
Hypothesis/Objective: To identify differentiating features on cross-sectional imaging in dogs with pituitary adenomas, invasive adenomas, and adenocarcinomas.
Animals: Thirty-three dogs that had computed tomography (CT) or magnetic resonance imaging (MRI) performed and a necropsy diagnosis of pituitary adenoma ( n = 20), invasive adenoma ( n = 11), or adenocarcinoma ( n = 2).
Methods: Medical records were retrospectively reviewed for signalment, history, and diagnosis. CT and MR images were reviewed for characteristics of pituitary tumors.
Results: Mean (± standard deviation) age for dogs with pituitary adenomas (10.6 ± 2.9 years) was greater than that of those with invasive adenomas (8.3 ± 2.7 years, P = .04). Eighteen out of 20 (90%) dogs with adenomas had contrast-enhancing masses. Thirteen out of 20 (65%) had homogeneous enhancement. Mean adenoma height was 1.2 ± 0.7 cm. Eight out of 20 (40%) adenomas were round and 8/20 (40%) compressed surrounding brain. Eleven out of 11 dogs (100%) with invasive adenomas had contrast-enhancing masses. Seven out of 11 (64%) masses were homogeneous. Mean invasive adenoma height was 1.8 ± 0.7 cm, which was significantly greater than adenomas ( P = .03). Mass shape varied from round to oval to irregular. Six out of 11 (55%) masses compressed surrounding brain. Clinical and imaging features were variable for 2 dogs with adenocarcinomas.
Conclusions and Clinical Relevance: Invasive adenoma should be suspected if a dog with a pituitary tumor is <7.7 years of age and has a mass >1.9 cm in vertical height. Adenocarcinomas are uncommon and metastatic lesions were not seen with imaging.     

Glutathione, Cysteine, and Ascorbate Concentrations in Clinically Ill Dogs and Cats

Background: Oxidative stress plays a role in the pathogenesis of many systemic diseases. Hospitalized human patients are glutathione, cysteine, and ascorbate deficient, and antioxidant depletion has been correlated with poor clinical outcome. To date little is known about antioxidant concentrations in hospitalized veterinary patients. The purpose of this study was to determine whether ascorbate, cysteine, or glutathione depletion is present in ill dogs and cats compared with healthy controls.
Hypothesis: Clinically ill dogs and cats would be antioxidant depleted, and depletion would correlate with illness severity and clinical outcome.
Animals: Clinically ill client-owned dogs (n = 61) and cats (n = 37), healthy control dogs (n = 37) and cats (n = 33).
Methods: Prospective, observational, case control study. Erythrocyte reduced glutathione, plasma cysteine, and plasma ascorbate were quantified using high-performance liquid chromatography.
Results: Clinically ill dogs had significantly lower erythrocyte glutathione concentrations (1.22 mM, range 0.55–3.61) compared with controls (1.91 mM, range 0.87–3.51; P = .0004), and glutathione depletion correlated with both illness severity ( P = .038) and mortality ( P = .010). Cats had higher ascorbate concentrations when ill (10.65 μM, range 1.13–25.26) compared with controls (3.68 μM, range 0.36–13.57; P = .0009).
Conclusions and Clinical Importance: Clinically ill dogs had decreased erythrocyte glutathione concentrations, which could be a marker of illness severity and prognostic of a poor outcome. Clinically ill cats had an unexpectedly high plasma ascorbate, which could represent a unique species response to oxidative stress.