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.

Successful balloon angioplasty of pulmonary artery stenosis in two cats and associated complications.

Two cats (2.5 months and 8 months old) were each evaluated due to a loud systolic murmur, and each was diagnosed with severe pulmonary artery stenosis at the bifurcation of the main pulmonary artery. Echocardiograms confirmed significant right atrial dilation and right ventricular dilation and/or hypertrophy that was progressive in one cat. Atenolol was initiated and the cats were referred for interventional therapy. Balloon angioplasty was performed via the jugular vein. In case 1, the pressure gradient across the stenosis was reduced from 169.7 mmHg to 23.6 mmHg and 52.4 mmHg across the left and right branch pulmonary arteries, respectively. In case 2, the stenotic echocardiographic gradient was reduced from 64 mmHg to 38.0 mmHg and 35.3 mmHg across the left branch and right-branched pulmonary arteries respectively. Both patients developed moderate to severe dynamic right ventricular outflow tract obstruction post angioplasty. Case 2 developed hypotension, desaturation, and ventricular arrhythmias intra-operatively. Case 1 was discharged but appeared to develop acute lung perfusion injury approximately 36 h after procedure that was manifested by radiographic pulmonary congestion and pulmonary infiltrate of the left lung fields. The congestion was successfully managed medically. Serial echocardiograms over the following 4 years in case 1 showed near complete resolution of the stenosis and associated right heart enlargement.

Colchicine reduces restenosis after balloon angioplasty treatment for in-stent restenosis.

BACKGROUND AND AIMS: Treatment of coronary in-stent restenosis (ISR) is hampered by a high incidence of recurrent ISR. Colchicine is an old drug with known anti-inflammatory and antiproliferative actions. We evaluated the strategy of colchicine combined with conventional balloon angioplasty for the treatment of ISR. METHODS AND RESULTS: Sixty coronary arteries of 60 mini-pigs underwent oversized bare-metal stent implantation to induce ISR. After 28 days, vessels with ISR (≥50% diameter stenosis) were randomly divided into three groups: control (conventional balloon angioplasty combined with placebo), colchicine (conventional balloon angioplasty combined with colchicine) and drug-eluting balloon (DEB). Restenosis and neointima formation were elevated with angiography and histological and morphometric analysis at 28 days after different interventions. Late lumen loss and percent area stenosis at follow-up were lower in colchicine group compared to control group but were similar to those of DEB group. There was no significant difference in proliferating cell nuclear antigen-positive vascular smooth muscle cells and inflammatory score between the colchicine group and the DEB group. CONCLUSIONS: The efficacy of colchicine combined with conventional balloon angioplasty for treatment of ISR was comparable to that of DEB. Treatment of ISR might not require a second stent implantation, and colchicine combined with conventional balloon angioplasty seemed to be another consideration.

Palliative balloon angioplasty in a cat with right pulmonary arterial branch stenoses and concurrent absence of the left pulmonary artery.

Unilateral absence of the left or right pulmonary artery with concurrent contralateral pulmonary arterial branch stenoses is an exceptionally rare disorder. We describe this anomaly in a cat with severe exercise intolerance and respiratory distress. Transthoracic echocardiography and angiography demonstrated the absence of the left pulmonary artery with concurrent right pulmonary branch stenosis. Palliative balloon angioplasty of the right pulmonary artery substantially reduced right ventricular systolic pressure load and alleviated the patient's clinical signs.

Hybrid cutting balloon dilatation for treatment of cor triatriatum sinister in a cat.

A hybrid surgical approach and balloon dilatation were performed successfully in a cat with cor triatriatum sinister and clinical signs of congestive heart failure. Left lateral thoracotomy was used to access the heart and cutting balloon followed by standard balloon dilatation were utilized to dilate the perforation in the anomalous left atrial membrane. Clinical signs resolved completely after dilation of the anomalous left atrial membrane. Based upon the outcome of this case, balloon dilatation appears to be a viable treatment option for cats affected with cor triatriatum sinister.

Percutaneous occlusion of a muscular ventricular septal defect with an Amplatzer muscular VSD occluder.

Ventricular septal defects are a relatively common congenital cardiac disease that, when severe, can be associated with substantial morbidity and mortality. Several minimally invasive methods of repair have been described in the human literature. This report describes the first case of percutaneous closure of a naturally occurring muscular septal defect using an Amplatzer occluder in a dog affected by concurrent pulmonic stenosis. Based on this experience catheter-based occlusion of muscular ventricular septal defects is a feasible option in dogs. Further studies are necessary to identify the attributes and limitations of the technique.

Mortality rates of interventional and surgical procedures performed in domestic juvenile farm pigs and Yucatan mini-pigs.

Perioperative and postoperative care are critical factors in cardiac catheterization and cardiothoracic surgical procedures. A retrospective analysis of mortality data in cardiovascular catheter and surgical studies performed in domestic juvenile swine (DJS) and Yucatan mini-swine (YMS) was conducted. A total of 529 animals in 35 studies were included in the analysis, which included six study categories: coronary stenting (Stent) and percutaneous transluminal coronary angioplasty (PTCA) alone; Stent and PTCA in combination with ionizing radiation (Stent/Rad, PTCA/Rad); myocardial ischemia (ISCH); and three non-ISCH surgical procedures grouped under "other surgeries" (Other Surg). Casualties were defined as animals that died spontaneously before the assigned termination date. The highest mortality rate occurred in the ISCH group (29.7% +/- 2.2%). Mortality of the Stent/Rad animals (26.1% +/- 6.3%) was significantly higher than those in the Stent and PTCA groups (12.1% +/- 3.1% and 7.9% +/- 3.2%; P< 0.05 for both). Similarly, mortality in the ISCH group was significantly higher than that in the Stent, PTCA, or Other Surg animals (29.7% +/- 2.2% versus 12.1% +/- 3.1%, 7.9% +/- 3.2%, and 3.0% +/- 3.0%, respectively; P< 0.05 for all comparisons). We did not observe differences between YMS and DJS. Most casualties in the ISCH group took place during weeks 1 (28.0% +/- 8.4%) and 4 (29.3% +/- 6.2%) after placement of the coronary ameroid constrictor. The majority of animals in the Stent/Rad and PTCA/Rad groups died within 1 week after the procedure (67.7% +/- 12.8% and 79.3% +/- 12.5%, respectively). We conclude that radiation therapy used in combination with stenting increases the mortality rate of this catheter-based procedure. Animals subjected to ISCH or a transcatheter procedure in combination with ionizing radiation should be monitored closely during the perioperative period to prevent unacceptably high mortality rates.

Experimental intracoronary stenting: comprehensive experience in a porcine model.

Appropriate animal models for intracoronary stenting are most important for improving understanding of the pathophysiology of acute occlusion and long-term re-stenosis, which currently limits the safety and efficacy of percutaneous transluminal coronary angioplasty in humans. Since the anatomy and physiology of swine coronary arteries closely resemble those of humans, the procine model should be ideal for testing of stents. This is a comprehensive report on an experimental set-up in pigs, communicating in detail the necessary techniques as well as some modifications facilitating safe intracoronary stent placement and successful follow-up studies for weeks or months. Stent procedure is performed in mechanically ventilated and haemodynamically monitored animals under balanced anaesthesia. Intracoronary application of flow wires allows the assessment of local flow conditions, flow properties and coronary flow reserve. Real-time intravascular ultrasonography (IVUS) provides detailed information on coronary morphology and enables the appropriate sizing of the coronary lumen. From our own experience, we like to propose that the use of the porcine model has the potential to gain new insights into the pathophysiology of intracoronary stent placement-associated complications and allows for the study of modifications in techniques and materials, and the development of novel pharmacological therapeutic strategies.