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Background – Ovariectomized sheep are a useful model of postmenopausal osteoporosis and other postmenopausal conditions. Estrogen may have a protective effect on the coronary arteries in postmenopausal women. The effects of raloxifene, a selective estrogen receptor modulator, on coronary arteries in aged ovariectomized ewes was investigated. Methods and Results – Forty eight aged ewes were randomly assigned to undergo sham surgery (Sham, n=7), ovariectomy (OVX, n=10), ovariectomy with estradiol supplementation (OVXE, n=8), ovariectomy with raloxifene supplementation, 0.02 mg/kg per day (RAL1, n=10), or ovariectomy with raloxifene supplementation, 0.10 mg/kg per day (RAL2, n=13). Contrast coronary angiography was performed 6 months after intervention. Diameters of the right main and left anterior descending coronary arteries in the RAL1, RAL2 and Sham groups were not different from each other, but were significantly greater than the OVX and OVXE groups. Intracoronary nitroglycerin did not affect the relationships of the diameters in any group. There were no differences in vascular remodeling between the groups. Conclusions – The results indicate that raloxifene in this sheep model allows greater dilation of coronary arteries than estrogen. Raloxifene may provide a significant protective functional effect on coronary arteries in postmenopausal heart disease.

Objectives— To determine the effect of the route and rate of protamine administration on the amount of protamine that could be delivered before a hemodynamic reaction occurred in dogs. Study design— Prospective randomized experimental study. Animals— Twenty adult mixed-breed dogs weighing 25.1 ± 2.5 kg. Methods— Before vascular surgery, the dogs were heparinized to reach an activated clotting time (ACT) of 300 seconds. After completion of the vascular surgery, protamine was administered intravenously until a hemodynamic reaction was recorded. The 4 groups of dogs were given protamine at 5 mg/min (slow) or 10 mg/min (fast) via the cephalic or the jugular veins. Systemic and pulmonary arterial pressures, central venous pressure (CVP), and pulmonary arterial occlusion pressure (PAOP) were recorded before and after protamine administration. The dose of protamine was recorded when a reaction occurred, which was defined as mean arterial pressure (MAP) 20 mm Hg or more than double the baseline value. Results— Significant decreases in systolic arterial pressure (SAP), MAP, and diastolic arterial pressure (DAP) and significant increases in systolic (SPAP), mean (MPAP), and diastolic (DPAP) pulmonary arterial pressures were recorded after protamine administration. The cephalic slow group had significantly fewer protamine reactions than other groups (chi-square = 8.57, P = .03, df = 3). Significantly more protamine could be delivered from the cephalic vein (52.5 ± 14.5 mg) compared with the jugular vein (37.6 ± 16 mg) before a reaction occurred (P = .048). Conclusion— The rate of administration did not have an effect on the amount of protamine delivered. Adverse reactions were minimized when protamine was administered via the cephalic vein at a slow rate. Clinical Relevance— We would recommend delivering protamine after cardiopulmonary bypass or vascular surgery through a peripheral venous route.

Objective—To compare outcome and intermediateterm survival for dogs undergoing open surgical correction of subvalvular aortic stenosis (SAS) with those for dogs with SAS that did not undergo surgery. Design—Retrospective study. Animals—44 dogs with congenital SAS. Procedure—Maximum instantaneous systolic pressure gradients were determined by use of Doppler echocardiography. Cardiopulmonary bypass and open surgical correction of SAS (membranectomy with or without septal myectomy) was performed in 22 dogs, whereas 22 dogs did not undergo surgical correction. Cumulative survival was compared between surgical and nonsurgical groups, using Kaplan-Meier nonparametric analysis and a Mantel-Cox log-rank test. Results—Initial systolic pressure gradients were not significantly different for dogs undergoing surgery (128 ± 55 mm Hg), compared with those that did not undergo surgery (117 ± 57 mm Hg). Systolic pressure gradients were significantly decreased after surgery in dogs that underwent surgery (54 ± 27 mm Hg). Cumulative survival was not significantly different between dogs in the surgical and nonsurgical groups. Censoring surgery-related mortality in the analysis still did not reveal a significant difference in cumulative survival between the surgical and nonsurgical groups. Conclusion and Clinical Relevance—Despite reductions in the systolic pressure gradient and possible associated improvement in exercise tolerance, a palliative benefit on survival was not documented in dogs undergoing surgery for SAS. (J Am Vet Med Assoc 2000;216:364–367)

Objective—To evaluate effect of 3 loading doses of warfarin sodium on the international normalized ratio (INR) for dogs. Animals—18 dogs weighing between 25 and 30 kg. Procedure—Dogs were randomly allocated into 3 groups and received 2, 4, or 6 mg of warfarin administered orally once a day for 2 days after surgery for bilateral iliac artery grafting. Activated partial thromboplastin (APTT) and prothrombin times (PT) were measured before and after treatment. Prothrombin time also was reported as an international normalized ratio. Results—The APTT were not significantly different among groups before or after treatment. The INR and PT were significantly increased in all groups after treatment. The INR and PT of the 6-mg group were significantly greater than those of the 2-mg and 4-mg groups. None of the dogs had clinical evidence of bleeding. Conclusions and Clinical Relevance—A warfarin loading dose of 6 mg/d can be safely administered for 2 days to dogs weighing between 25 and 30 kg. Anticoagulation can be achieved safely in dogs in 2 days by use of warfarin. The effects of warfarin can be monitored with the INR. (Am J Vet Res 2000;61:48–50)

Background: To eliminate the noncardiac toxicities associated with Adriamycin (Pharmacia Upjohn, Kalamazoo, MI) and to avoid the need for surgical implantation of a coronary artery catheter, we proposed serial intracoronary infusions of Adriamycin (Pharmacia Upjohn) with a Judkins catheter to develop a nonsurgical but selective model of dilated cardiomyopathy in dogs. Methods and Results: Twenty-two dogs were entered onto the study. Each dog received four weekly injections of Adriamycin (Pharmacia Upjohn; 15 mg/wk) through a Judkins catheter and verapamil orally (5 mg/kg twice daily) for 4 weeks. Dogs were evaluated with echocardiography, right-sided cardiac catheterization, and endomyocardial biopsy at times 0 and 10 weeks. The left ventricular ejection fraction decreased from 0.65 ± 0.04 to 0.48 ± 0.11 (P = .0006). The left ventricular end-diastolic and end-systolic diameter indices increased from 42.00 ± 2.17 to 46.92 ± 5.81 mm (P = .0029) and from 27.65 ± 2.59 to 35.00 ± 6.84 mm, respectively (P = .0210). The mechanical cardiac efficiency decreased from 28.55% ± 13.30% at baseline and 15.64% ± 9.09% at 10 weeks (P = .001). Cardiac myocyte vacuolation was present on histological examination at 10 weeks. The mortality rate was 41%. Minimal systemic Adriamycin (Pharmacia Upjohn) toxicity was noticed. Conclusion: Intracoronary injection of Adriamycin (Pharmacia Upjohn) in dogs induced a chronic dilated cardiomyopathy.

Objective: Functional mitral regurgitation (FMR) is a common sequelae of myocardial ischemic disease. It results from annular dilation and outward rotation of the posterior papillary muscle. Different surgical techniques are under investigation for the treatment of FMR. However, an ex vivo model of FMR would be valuable to develop and compare the effect of techniques on the geometry of the left ventricle and the correction of FMR.Methods: FMR was induced in explanted ovine hearts (n = 12) by manual dilation of the mitral annulus or by posterior papillary muscle repositioning with a patch. Left ventricular dimensions were measured. Mitral regurgitant volume (MRV) was measured in a continuous flow system.Results: Annular dilation significantly increased MRV from 93.0 � 110.4 to 472.2 � 211.8 mL/min (P = 0.031), and the patch increased it from 37.8 � 55.2 to 365 � 189.6 mL/min (P = 0.031), with no significant differences between the 2 groups. When both techniques were applied, MRV significantly increased to 1383.5 � 567.0 mL/min (P = 0.0005). The left ventricular sphericity index decreased from 3.25 � 0.7 to 2.34 � 0.6 (P = 0.0025) after application of the patch. The posterior papillary muscle was displaced after patch placement, following an outward rotation.Conclusion: This ex vivo model reproduces annular dilation and outward rotation of the posterior papillary muscle, which are both present during FMR after ischemic myocardial disease. This model could be used to evaluate and compare interventions to treat FMR.

La position de la France is-a-vis du dollar pendant les annees 1960 ne se resume pas a une exploitation politique par le general de Gaulle du deficit de la balance des paiements des Etats-Unis. Cet article montre comment s'est construite une ision francaise coherente des failles du systeme de Bretton Woods et comment celle-ci a abouti a une serie de propositions de reformes isant a definir de nouvelles « regles du jeu » pour la discipline monetaire et la cooperation internationale entre banques centrales. En etudiant le fonctionnement du consortium de l'or, la proposition d'unite de reserve collective et la politique de la Banque de France entre 1960 et 1965, nous montrons que trois facteurs principaux expliquent la position francaise : l'heritage des negociations de l'entre-deux-guerres, l'incapacite des Etats-Unis a organiser une cooperation multilaterale et les nouveaux instruments de la politique monetaire interieure francaise.

Popliteal tendon transposition was performed in five dogs with surgically induced cranial cruciate ligament rupture. After a lateral approach to the stifle joint, the popliteal tendon was severed distal to the sesamoid bone and transposed cranially onto the tibial crest to mimic the sagittal orientation of the cranial cruciate ligament. The origin of the popliteal tendon on the lateral femoral condyle was preserved. Lameness was not clinically detectable 2 months after surgery. At 6 months postoperatively, there was minimal radiographic and histopathologic evidence of degenerative joint disease in the stifle joints that had underwent surgery. There was no gross or microscopic evidence of meniscal damage found at necropsy 6 months after surgery. Biome-chanical studies are warranted before recommending the procedure.

A multicentre retrospective study of dogs that underwent surgical attenuation of portosystemic communications (PSC) was conducted. These dogs were followed from three months after surgery to evaluate the long term effect of surgery on their life span, disease-free interval, and owner assessment of postoperative quality of life of the dogs. Seventy-five per cent of the dogs in this study had no long term postoperative recurrence of clinical signs. Of the 25 per cent of dogs that showed recurrent clinical signs, all but one had partial attenuation of the PSC. The location of the PSC was the only factor that correlated with whether the dogs were still alive. All owners were pleased with the postoperative quality of life of their dogs.

To further define the prognosis and identify clinical findings predictive for survival in dogs with dilated cardiomyopathy (DCM), we performed Kaplan Meier survival analysis of 37 dogs with idiopathic DCM. Survival analysis showed that the 50% probability of survival occurred at 2.3 months. Probability of survival at 1 year was 37.5% and at 2 years was 28%. Bivariate Cox proportional hazard ratios identified pleural effusion and pulmonary edema, both signs of congestive heart failure, as independent prognostic indicators for dogs with DCM (P < .01). Hazard ratios for these prognostic indicators were 2.354 and 3.291, respectively. Multivariate Cox stepwise regression identified pleural effusion, left ventricular free-wall thickening fraction, ventricular ectopy, and weight loss as significant prognostic indicators for dogs with DCM. Because of the retrospective nature of this study, the effects of different drug treatments were not evaluated. The type of cardiac-related death, progressive failure versus sudden death, was not addressed in this study and requires further evaluation.

Stapling devices useful for cardiovascular applications include vascular clips, the ligation and division stapler, the thoracoabdominal stapling device with vascular load, and the pin-ring device of small vessel anastomosis. This article addresses the application, indication, advantages, and disadvantages of each of these devices.

Contrast enhanced magnetic resonance angiography (MRA) can provide noninvasive relatively rapid three-dimensional high-detailed vascular images over large anatomic areas. There are few descriptions of the use of contrast-enhanced MRA in veterinary patients. This is a report illustrating the use of contrast-enhanced MRA to localize the full extent of distal aortic, external iliac, and femoral artery thrombi confirmed surgically in four dogs. Distal aorta contrast-enhanced MRA was anatomically accurate in detecting the full extent of thrombi involving the aorta, external iliac and femoral arteries in these four canine patients. This procedure can provide important information for surgery.

CoSeal mark surgical sealant (CoSeal) was evaluated for inhibiting suture line bleeding using a canine iliac PTFE graft model. Both iliac arteries of 12 heparinized canines were grafted with PTFE. CoSeal was applied to the suture lines of one graft in each animal. The contra-lateral graft served as a control and bleeding was controlled with gauze and pressure (tamponade). The cross-clamps were removed 30 s following application of CoSeal. Times to hemostasis and volume of blood loss at each graft site were determined. Compared to tamponade control, CoSeal significantly reduced the time to hemostasis (average of 5 min vs. greater than 15 min, p < 0.05) and blood loss (19 g vs. 284 g, p < 0.05). Small amounts of CoSeal were visible grossly or histologically at day 7. Histology showed moderate to marked inflammation in CoSeal sites and moderate inflammation in control sites at day 7. At 30 and 60 days, no CoSeal was visible grossly or histologically. Histology showed moderate inflammation in both CoSeal treated sites and in control sites at day 30 and mild to moderate inflammation in both CoSeal and control sites at day 60. CoSeal significantly reduced the time to hemostasis and blood loss in comparison to tamponade.

Objective—To evaluate the effect of protein concentration on rate of closure of ameroid constrictors in vitro. Sample Population—Twenty-four 3.5-mm ameroid constrictors. Procedure—Ameroid constrictors were equally allocated into 4 treatment groups; constrictors were placed in saline (0.9% NaCl) solution (control) or plasma diluted with saline solution to obtain protein concentrations of 1.5, 3, or 6 g/dL. Ameroid constrictors were incubated for 27 days. A digital camera was used to image ameroid constrictors in culture at 1, 6, 11, 16, 21, and 27 days, and the lumen diameter of each constrictor was measured. Results—None of the rings were completely closed at 27 days. Mean final lumen diameter was 0.205 ± 0.22 mm. Mean final lumen diameter of constrictors in the control group was significantly larger than that of constrictors in the 1.5, 3, and 6 g/dL groups. Constrictors in the 1.5 g/dL group closed to a larger diameter than that of constrictors in the 6 g/dL group. Constrictors in the control group had the smallest overall change in lumen diameter, compared with constrictors in the 3 and 6 g/dL groups. Constrictors in the 1.5 g/dL group had a significant decrease in overall lumen diameter, compared with constrictors in the 3 and 6 g/dL groups. The diameter of the ameroid lumen was a function of time and protein concentration. Conclusions and Clinical Relevance—High plasma protein concentrations resulted in rapid closure of the ameroid constrictor lumen. Complete closure of ameroid constrictors may not be attributable to imbibition of casein. (Am J Vet Res 2005;66:1337–1340)

Objective—To determine factors associated with long-term survival in dogs treated surgically for patent ductus arteriosus (PDA). Design—Retrospective case series. Animals—52 dogs treated surgically for left-to-right shunting PDA. Procedure—Data pertaining to age, breed, sex, body weight, clinical examination findings, type and duration of medical treatment, results of thoracic radiography and echocardiography, and surgical and postoperative complications were collected from records. Follow-up information was obtained from medical records or telephone interviews with owners or referring veterinarians. Results—22 dogs had mitral valve regurgitation. Mean weight and age were not significantly different between dogs with or without mitral valve regurgitation. Twenty-four (46.2%) dogs had clinical signs related to cardiac insufficiency. Left atrial dilatation was observed in 56.3% of dogs that were radiographed. Sonographic imaging was used to diagnose left atrial dilatation in 23 dogs and left ventricular dilatation in 25 dogs. The 1- and 2-year survival rates were 92% and 87%, respectively. Diagnosis of mitral valve regurgitation before surgery was not associated with the probability of survival. Age, weight, lethargy, preoperative treatment with angiotensin-converting enzyme inhibitors, and right atrial dilatation on radiographs at the time of surgery were negatively associated with probability of survival. Conclusions and Clinical Relevance—Surgical treatment of PDA was curative in young dogs without clinical signs of heart failure. Surgical correction of PDA should be recommended as early as possible after diagnosis, and mitral valve regurgitation is not a contraindication for surgery. (J Am Vet Med Assoc 2005;227:1794–1799)

Skeletal muscle deterioration is emerging as a limitation to long-term cardiac assist by dynamic cardiomyoplasty. Chronic electrical stimulation of in situ skeletal muscle showed that ischemia, decreased muscle preload, muscle overuse, and chronic electrical stimulation are factors for muscle deterioration. Transposition around the heart has been associated with signs of muscle denervation after chronic electrical stimulation. To evaluate latissimus dorsi muscle neuromuscular function after long-term dynamic cardiomyoplasty, we performed neuromuscular functional analysis and histology on the latissimus dorsi muscle and thoracodorsal nerve of six normal goats and six goats after 6 months of dynamic cardiomyoplasty. Electromyographic analysis showed positive sharp waves and fibrillation potentials in the latissimus dorsi of three goats from the dynamic cardiomyoplasty group. Conduction velocity of the thoracodorsal nerve of goats from the dynamic cardiomyoplasty group (58.32 ± 9.80 m/s) was reduced compared to the goats from the control group (71.48 ± 5.71 m/s, P = 0.02). Histologic changes in skeletal muscle were compatible with denervation. Loss of myelin sheaths, collapse of endoneurial connective tissue, and solitary foci of axonophagia and myelinophagia further documented severe injury to the thoracodorsal nerve in goats from the dynamic cardiomyoplasty group. The latissimus dorsi muscle wrap was denervated after long-term dynamic cardiomyoplasty. Traction on the neurovascular pedicle at each contraction of the transposed muscle may induce afferent axonal injury of the thoracodorsal nerve resulting in diminished muscular function.

Cases of flail chest injury for 24 client-owned companion animals following various traumas were evaluated. Concurrently sustained injuries, initial emergency treatments, and definitive treatment and outcome for regimens that utilize stabilization of the flail segment were compared with cases treated with no stabilization. Flail chest was confirmed in 24 animals: 21 dogs and three cats. There was an even division (12 each) of right and left flail segments. The median number of ribs involved was three (range, two to seven). Flail segment stabilization was performed in nine, and 15 were treated with no stabilization. Statistical analysis using multiple data permutations evaluating all combinations failed to reveal a significant difference in outcome between stabilized and unstabilized cases.

A 2-year-old female Siberian Husky was referred for evaluation of a rectocutaneous fistula of unknown etiology. On evaluation, a rectal tear and an associated perivulvar abscess and draining tract were identified. Several attempts were made to repair the rectocutaneous fistula and associated rectal tear. Primary repair and fascia lata graft repair failed. Successful management was achieved via a laparoscopic-assisted end-on jejunostomy for fecal diversion, and the wound healed readily by second intention. During the period of hospitalization, the dog lost a considerable amount of weight. Particular care should be taken regarding fluid therapy, administration of antimicrobials, and adequate nutrition in patients with rectocutaneous fistulas. Overall, the use of laparoscopic-assisted end-on jejunostomy for fecal diversion in the management of rectocutaneous fistulas in dogs appears to be feasible; end-on or loop jejunostomy may also be an option for the treatment of other diseases of the distal portion of the gastrointestinal tract.

Objective— To determine if transcostal thoracotomy closure resulted in less pain than circumcostal closure. Study Design— Experimental cadaver and prospective clinical study. Animals— Two canine cadavers and 13 adult, 22–29 kg dogs. Methods—Phase 1: In 2 cadavers, 4 suture passage techniques were evaluated to determine the incidence of nerve entrapment in circumcostal intercostal thoracotomy closure. Phase 2: Pain after circumcostal closure (7 dogs) or transcostal closure (6 dogs) of a 4th intercostal space thoracotomy was evaluated by use of pain threshold scores, fentanyl administration rates, heart and respiratory rates, and numerical ratings for behavior. Arterial blood gas analyses were obtained 4 hours postoperatively. Transcostal closure was accomplished by drilling 5–6 small holes in the 5th rib and passing sutures through the holes and around the 4th rib to achieve closure. Pain threshold scores (PTS) were measured by an observer unaware of closure assignment, at 2, 4, 12, and 24 hours after closure by applying slowly increasing pressure to the incision line using a load cell. Rates of fentanyl administration were adjusted based on subjective impressions of dog comfort by a second observer unaware of closure assignment. Results— A 70–100% incidence of nerve entrapment was found for all circumcostal techniques. PTS was higher (P=.045) and fentanyl infusion rates were lower (P=.001) for the transcostal group at 2, 4, 12, and 24 hour postoperatively compared with the circumcostal group. Conclusion— There is a high incidence of nerve entrapment using circumcostal closure techniques. A transcostal technique appears to be associated with less pain during the first 24 hours postoperatively. Clinical Relevance— Based on lower pain scores, transcostal thoracotomy closure may be preferable to circumcostal closure techniques.