Successful balloon angioplasty in a cat with unilateral left pulmonary artery branch stenosis.

A 9-month-old intact male Ragdoll cat was presented for evaluation of a left-sided systolic murmur that was first auscultated during examination for a newly developed cough. Transthoracic echocardiography revealed a narrowed left pulmonary artery and an increase in flow velocities at the level of the narrowing, consistent with left pulmonary artery branch stenosis. The right pulmonary artery appeared normal. Balloon angioplasty was performed and successfully reduced pressure gradient across the stenosis. The patient continues to do well 14 months after the procedure.

Budd-Chiari-like syndrome in a dog secondary to a gunshot wound treated with balloon angioplasty and endovascular stent placement.

A 6-year-old female spayed Chihuahua mix presented with chronic recurrent ascites. Computed tomographic angiography revealed an isolated stenosis of the caudal vena cava secondary to a metallic foreign body, resulting in Budd-Chiari-like syndrome. Balloon angioplasty and endovascular stent placement successfully resolved the obstruction with long-term resolution of ascites.

Non-cardiogenic pulmonary oedema complicating balloon valvuloplasty and stent angioplasty of severe pulmonary valve stenosis in four dogs.

In dogs, balloon valvuloplasty is considered the treatment of choice for severe pulmonary valve stenosis, and this technique is currently performed routinely in specialist referral practices with low morbidity and mortality. Stent angioplasty has also been recently proposed as a viable treatment option. The present case series describes the clinical course of four dogs with severe pulmonary valve stenosis, treated with balloon valvuloplasty or stent angioplasty at four different institutions, which developed non-cardiogenic pulmonary oedema perioperatively after apparently successful dilation of the pulmonary valve. In three cases, there was evidence of some degree of pulmonary hypertension before ballooning. Despite intensive care, the complication proved fatal in three cases. Clinicians should therefore be aware of this life-threatening complication, previously undescribed in dogs.

Combined cutting balloon and conventional balloon angioplasty in a dog with supravalvular pulmonary stenosis.

A 7-year-old Miniature Schnauzer presented with exercise intolerance and easy fatigability. Echocardiography revealed the presence of supravalvular pulmonary stenosis. The peak velocity through the stenosis was 6.4 m/sec, and the interventricular septum was flattened. Cutting balloon angioplasty was designed for the treatment of coronary artery stenosis, which was resistant to conventional balloon angioplasty. Accordingly, the dog underwent cutting balloon angioplasty and conventional balloon dilation. One month after treatment, it showed neither exercise intolerance nor easy fatigability. The ventricular septum flattening disappeared. Five months later, the dog showed an increase in activity. Two years later, the peak velocity through the stenosis decreased to 4.4 m/sec. Neither clinical symptoms nor restenosis was observed. Thus, supravalvular pulmonary stenosis was successfully treated using this combination method. The present case showed that combined cutting balloon and conventional balloon angioplasty is a useful and minimally invasive treatment for supravalvular pulmonary stenosis.

Cutting balloon and high-pressure balloon dilation for palliative treatment of congenital double-chambered right ventricle and primary infundibular stenosis in a Golden retriever dog.

Combined cutting balloon and high-pressure balloon dilation was performed in a dog with a double-chambered right ventricle and severe infundibular stenosis of the right ventricular outflow tract. The peak systolic pressure gradient across the stenosis decreased by 65% after dilation (from 187 mmHg before to 66 mmHg after) affirming the intervention as successful. However, early re-stenosis occurred within 3 months leading to exercise intolerance, exercise-induced syncope, and right-sided congestive heart failure. Cutting balloon followed by high-pressure balloon dilation provided temporary but not long-term relief of right ventricular obstruction in this dog.

Balloon dilation of congenital supravalvular pulmonic stenosis in a dog.

Percutaneous balloon valvuloplasty is considered the standard of care for treatment of valvular pulmonic stenosis, a common congenital defect in dogs. Supravalvular pulmonic stenosis is a rare form of pulmonic stenosis in dogs and standard treatment has not been established. Although, there have been reports of successful treatment of supravalvular pulmonic stenosis with surgical and stenting techniques, there have been no reports of balloon dilation to treat dogs with this condition. Here, a case of supravalvular pulmonic stenosis diagnosed echocardiographically and angiographically in which a significant reduction in pressure gradient was achieved with balloon dilation alone is presented.

High-pressure balloon dilation in a dog with supravalvular aortic stenosis.

A 6-month-old female intact Goldendoodle was presented for diagnostic work up of a grade IV/VI left basilar systolic heart murmur. An echocardiogram was performed and revealed a ridge of tissue distal to the aortic valve leaflets at the sinotubular junction causing an instantaneous pressure gradient of 62 mmHg across the supravalvular aortic stenosis and moderate concentric hypertrophy of the left ventricle. Intervention with a high-pressure balloon dilation catheter was pursued and significantly decreased the pressure gradient to 34 mmHg. No complications were encountered. The patient returned in 5 months for re-evaluation and static long-term reduction in the pressure gradient was noted.

Expressão de citoquinas na camada média da parede da artéria ilíaca como resposta à agressão por balão ­ estudo experimental em coelhos / Cytokines expression in the middle layer of the iliac artery wall as a response to balloon catheter injury ­ a experimental study in rabbits

Objetivo: Avaliar a presença de mediadores pró-inflamatórios na camada média de artéria ilíaca de coelhos agredida por cateter-balão. Métodos: Foram estudados dez coelhos da raça Nova Zelândia, pesando entre 3kg e 4kg (idade aproximada de 100 dias). Os animais foram submetidos à angioplastia da artéria ilíaca comum esquerda, com cateter de fogart 4F e 48hs após a dilatação, o segmento aorto- -ilíaco dos animais foi ressecado para análise imuno-histoquímica da camada média de ambas as artérias ilíacas, utilizando-se a artéria ilíaca comum direita como controle. A expressão do fator de necrose tumoral-α (FNT-α) e da interleucina 1-ß (IL1-ß) foi obtida através da técnica de reação da Streptavidina/AP, utilizando-se anticorpos monoclonais específicos. Resultados: A IL1-ß apresentou expressão significativa na camada média da artéria submetida à angioplastia, enquanto o FNT-α não foi significativo quando comparados com as artérias-controle. Conclusão: A camada média da artéria agredida por cateter-balão apresenta resposta inflamatória envolvendo a participação de citoquinas(AU)

Objective: To evaluate the presence of pro-inflammatory mediators in the middle layer of the iliac artery of rabbits injured by balloon catheter. Methods: Ten New Zealand rabbits were studied, weighing 3-4 kg (approximate age 100 days). The animals underwent angioplasty of the left common iliac artery with Fogarty catheter 4F, and 48 hours after dilation the aorto-iliac segment of the animals was resected for immunohistochemical analysis of the tunica media of both iliac arteries, using the right common iliac artery as control. The expression of tumor necrosis factor ­ α (TNF ­ α) and interleukin 1 ­ ß (IL1 ­ & # 946) was obtained by Streptavidin/AP reaction technique using specific monoclonal antibodies. Results: IL1-#946 showed significant expression in the middle layer of the artery submitted to angioplasty, while TNF -&# 945 was not significant as compared with the controls. Conclusion: The middle layer of the artery injured by balloon catheter presents inflammatory response involving the participation of cytokines(AU)

Axillary artery tumor embolism secondary to mitral valve myxosarcoma in a dog.

OBJECTIVE: To describe the clinical presentation, treatment, and outcome of a dog with an arterial tumor embolism. CASE SUMMARY: An 11-year-old, neutered male Irish Setter presented with acute right forelimb lameness. The dog was unable to bear weight on the right forelimb, which was cool to the touch with no palpable pulses. Diagnosis of thromboembolism was confirmed using angiography, revealing a lack of blood flow to the right axillary artery. Balloon angioplasty, thrombosuction, and infusion of the thromboembolism with tissue plasminogen activator were used to achieve increased, but not complete, blood flow through the vasculature. Echocardiogram revealed vegetative mitral valve lesions consistent with endocarditis, thrombus, neoplasia, or a combination thereof. At the time of discharge, there was improvement in the temperature and motor function of the proximal limb but no conscious proprioception or deep pain sensation in the distal limb. Histopathologic analysis of the sample retrieved with thrombosuction was consistent with a diagnosis of myxosarcoma. A series of 3 rechecks showed continued improvement in neuromuscular function. Treatment for suspected mitral valve myxosarcoma was declined. The patient was lost to follow up until being presented for necropsy 16 months later. Necropsy confirmed myxosarcoma of the mitral valve with tumor emboli to the coronary arteries, lungs, and the right axillary artery. UNIQUE INFORMATION PROVIDED: To the authors' knowledge, there is no report of myxosarcoma originating on the mitral valve in dogs, although it has been reported in the human literature. To the authors' knowledge, there are also no reports of tumor embolism of the axillary artery in a dog. This case demonstrates a unique presentation of a dog that had a myxosarcoma tumor embolism. It also describes the use of angiography for diagnosis and localization of the vascular obstruction and a variety of interventional techniques for the treatment of thromboembolism.

Thrombectomy and thrombolysis: the interventional radiology approach.

OBJECTIVE: To present interventional therapeutic options for patients with thrombosis. ETIOLOGY: Thrombosis in small animals results from an unbalance in the normal hemostatic mechanisms leading to vessel occlusion. In veterinary medicine, thrombosis is recognized as a common complication of many acquired diseases, including cardiac, endocrine, immunological, inflammatory, and neoplastic disorders. DIAGNOSIS: Clinical signs are variable depending on the location of the thrombus and various laboratory and imaging modalities can aid in its identification and localization. THERAPY: Once identified, a decision must be made to whether or not intervene and which method is most appropriate. A number of minimally invasive approaches for dealing with thrombosis are available and offer veterinarians a choice of therapeutic options when dealing with a thrombotic patient. In the presence of thrombosis, a combined approach of vessel balloon dilatation, catheter-directed thrombolysis and stenting may be most appropriate. Percutaneous mechanical thrombectomy, if available, may also be appropriate. Embolic trapping devices can be used with vena cava thrombosis to help prevent pulmonary embolism. Anticoagulant therapy may be indicated in the postoperative period to prevent further thrombus formation while the patient's fibrinolytic system breaks the clot down. PROGNOSIS: Outcome is variable depending on the site of the thrombus formation. Arterial thrombosis can be life-threatening while venous thrombosis tends to be less life-threatening but may lead to pulmonary embolism.

Successful treatment of pacemaker-induced stricture and thrombosis of the cranial vena cava in two dogs by use of anticoagulants and balloon venoplasty.

CASE DESCRIPTION: 2 castrated male Labrador Retrievers (dogs 1 and 2) were evaluated 3 to 4 years after placement of a permanent pacemaker. Dog 1 was evaluated because of a large volume of chylous pleural effusion. Dog 2 was admitted for elective replacement of a pacemaker. CLINICAL FINDINGS: Dog 1 had mild facial swelling and a rapidly recurring pleural effusion. Previously detected third-degree atrioventricular block had resolved. Cranial vena cava (CVC) syndrome secondary to pacemaker-induced thrombosis and stricture of the CVC was diagnosed on the basis of results of ultrasonography, computed tomography, and venous angiography. Dog 2 had persistent third-degree atrioventricular block. Intraluminal caval stricture and thrombosis were diagnosed at the time of pacemaker replacement. Radiographic evidence of pleural effusion consistent with CVC syndrome also was detected at that time. TREATMENT AND OUTCOME: Dog 1 improved after treatment with unfractionated heparin and a local infusion of recombinant tissue-plasminogen activator. Balloon venoplasty was performed subsequently to relieve the persistent caval stricture. In dog 2, balloon dilatation of the caval stricture was necessary to allow for placement of a new pacing lead. Long-term anticoagulant treatment was initiated in both dogs. Long-term (> 6 months) resolution of clinical signs was achieved in both dogs. CLINICAL RELEVANCE: Thrombosis and stricture of the CVC are possible complications of a permanent pacemaker in dogs. Findings suggested that balloon venoplasty and anticoagulation administration with or without thrombolytic treatment can be effective in the treatment of dogs with pacemaker-induced CVC syndrome.

Percutaneous balloon pericardiotomy for the management of malignant pericardial effusion in two dogs.

Two dogs with signs of right-sided congestive cardiac failure, due to recurrent pericardial effusion secondary to the presence of intrapericardial neoplasia, were treated by percutaneous balloon pericardiotomy. The first patient was euthanased one month after the procedure while the second patient developed ascites as a result of obstruction of the caudal vena cava by the growing tumour and was euthanased 14 weeks after the procedure. In neither case was there a recurrence of a significant volume of the effusion. Percutaneous balloon pericardiotomy represents an effective means of relieving recurrent malignant pericardial effusion, without resorting to thoracotomy.

Balloon-tipped catheter arterial occlusion for prevention of hemorrhage caused by guttural pouch mycosis: 13 cases (1982-1985).

Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, catheter breakage during removal occurred twice, and in one horse, a catheter was inappropriately placed.