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.

Transvalvular pulmonic stent angioplasty: procedural outcomes and complications in 15 dogs with pulmonic stenosis.

INTRODUCTION: Balloon valvuloplasty is the treatment of choice for dogs with severe type A pulmonic stenosis (PS), but less successful for dogs with annular hypoplasia and unsuitable for supravalvular stenosis or cases with a circumpulmonary coronary malformation. We report outcomes and complications of the first 15 consecutive transvalvular pulmonic stent angioplasty procedures performed by a single center in dogs with PS. ANIMALS: Fifteen dogs with naturally occurring PS were included in the study. MATERIALS AND METHODS: Dogs underwent echocardiography before and four weeks after the procedure. Transvenous approaches were used to deploy a pre-mounted, balloon-expandable metallic stent in all cases. RESULTS: Of 15 dogs, all had annular hypoplasia, and in addition, supravalvular stenosis was diagnosed in 11 of 15 dogs, and three had R2A coronary malformation. All dogs survived to discharge. One dog died less than four weeks postoperatively (non-cardiac), but 14 of 15 dogs were re-examined at four weeks. Severity reduced in all cases; median pressure gradient reduced from 137 mmHg (range 81-202 mmHg) to 83 mmHg (range 31-155 mmHg). Clinical signs improved in all cases, and hematocrit reduced in all dogs with erythrocytosis. The median follow-up time was 280 days (range 95-896 days). Over one-year follow-up was available in six of fifteen dogs. Two dogs died because of refractory right-sided congestive heart failure signs: one at 10 months and one at 22 months postoperatively. CONCLUSIONS: Transvalvular pulmonic stent angioplasty technique was associated with an improvement in clinical signs and reduction in stenosis severity for all dogs in this population, including cases with supravalvular PS or circumpulmonary coronary malformation.

Análise morfométrica da carótida de suínos submetidos a angioplastia com ou sem implante de stent de cromo-cobalto / Morphometric analysis of swine carotid artery angioplasty with or without cobalt-chromium stent implantation

Contexto: A hiperplasia intimal é a reação tardia mais comum decorrente da angioplastia. O uso de stents de cromo-cobalto é bem estudado na circulação coronariana, porém não há muitos estudos que abordem o uso desses stents nas circulações carotídea e periférica. Objetivo: Analisar mediante morfometria a reação intimal presente na artéria carótida de suínos submetidos a angioplastia isoladamente e a angioplastia seguida de implante de stent de cromo-cobalto. Materiais e métodos: Em oito suínos, foi realizada angioplastia da artéria carótida comum direita e angioplastia seguida de implante de um stent de cromo-cobalto na artéria carótida comum esquerda. Após 4 semanas, os animais foram submetidos a eutanásia para a retirada de amostras de tecido arterial e preparo de lâminas histológicas. As imagens das lâminas foram digitalizadas e analisadas por programa de morfometria digital. A análise estatística foi realizada através da média e desvio padrão das áreas em cada grupo, utilizando-se o Teste t de Student. O valor de p < 0,05 foi considerado significativo. Resultados: O implante do stent provocou maior grau de hiperplasia comparado à angioplastia isolada. A diferença em resposta ao implante de stent foi estatisticamente significativa quando as áreas do lúmen, da lâmina elástica interna e da lâmina elástica externa foram comparadas entre os dois grupos. Não se observou diferença significativa quando se realizou a comparação entre as camadas médias dos dois grupos. Conclusão: O implante de stent de cromo-cobalto gerou um espessamento intimal maior do que o produzido apenas pela angioplastia, porém ele não foi suficiente para reduzir o lúmen arterial.

Background: Intimal hyperplasia is the most common delayed response to angioplasty. The use of cobalt-chromium stents is well studied in the coronary circulation; however, there are few studies on their use in the carotid and peripheral circulation. Objective: To analyze the intimal reaction in a swine carotid artery undergoing simple angioplasty and angioplasty followed by implantation of cobalt-chromium stent. Materials and methods: We carried out angioplasty in the right common carotid artery and angioplasty with cobalt-chromium stent in the left common carotid artery in eight swine. Four weeks later, all animals were sacrificed for arterial tissue sampling and preparation of histological slides. Slide images were scanned and analyzed using a digital morphometry program. Statistical analysis was performed by mean values and standard deviations of the areas in each group, using the Student's t test. A p value of < 0.05 was considered significant. Results: Angioplasty with cobalt-chromium stent implantation resulted in a higher degree of hyperplasia compared with simple angioplasty. The difference was statistically significant when the lumen area, the internal elastic lamina area, and the external elastic lamina area were compared between the two groups. No statistically significant difference was found when the media layers of both groups were compared. Conclusion: Cobalt-chromium stent implantation resulted in more intimal hyperplasia than simple angioplasty, however the stent was not enough to reduce the arterial lumen.

Femoral artery pseudoaneurysm in a monkey.

Pseudoaneurysm formation as a complication of routine blood collection was diagnosed in a monkey. Damage to the femoral artery resulted in hematoma formation with secondary organization, encapsulation, and vascular communication. Progressive lameness and muscular atrophy were the primary clinical signs. Surgical correction of the artery defect helped resolve the monkey's lameness and muscle atrophy.