A new balloon-expandable tantalum coil stent: angiographic patency and histologic findings in an atherogenic swine model.

The angiographic patency and histologic characteristics of a new balloon-expandable tantalum stent were studied after implantation intervals ranging from 1 to 32 weeks in atherogenic miniature swine peripheral and coronary arteries. Stents were placed in 34 arteries (10 coronary and 24 iliac arteries) in a total of 13 swine. Two swine died within 24 h of stent implantation. Follow-up angiography was performed before death was induced in 11 swine (8 coronary and 19 iliac arteries) and revealed 100% patency without evidence of lumen stenosis, thrombosis or migration of the stents. The neointimal thickening was maximal at 4 weeks after stent implantation and was at its minimum at 32 weeks after implantation with reendothelialization of the stents generally complete at that time. An advantage of this balloon-expandable device is its inherent longitudinal flexibility. The coil configuration allowed the nondeployed stent to negotiate acute bends in coronary arteries to reach the site of implantation and also allowed the deployed stent to conform to the natural contour of tortuous coronary arteries. The tantalum device was remarkable for its radiographic visibility, which greatly aided its placement under fluoroscopic guidance. This study demonstrates this stent's ease of implantation, excellent patency rate and absence of restenosis due to neointimal proliferation for up to 8 months in this atherogenic swine model.

Anomalous origin and course of coronary arteries in adults: identification and improved imaging utilizing transesophageal echocardiography.

Anomalous origin of a coronary artery is rare, but may represent a clinically significant abnormality, since some anomalies are associated with myocardial ischemia, infarction, and sudden death. Diagnosis may elude routine screening procedures, and even when an anomalous vessel is identified angiographically, it may be difficult to delineate its true course on the basis of angiography alone. The purpose of this study was to determine whether transesophageal echocardiography (TEE) is of value in making the diagnosis and outlining the course of anomalous coronary arteries. Five adult patients with anomalous origin of a coronary artery were studied by monoplane TEE and selective coronary angiography. Transthoracic echocardiography (TTE) was also performed in four of these five patients. Anomalous coronary ostia were visualized in four of five patients utilizing TEE, but in none of four patients by TTE. A proximal segment of the anomalous coronary vessel was identified in all five patients by TEE, and in only two of four patients by TTE. TEE images were consistently of superior diagnostic quality. TEE is a valuable tool for the echocardiographic identification of anomalous coronary arteries, and is superior to TTE in adult patients.

Percutaneous transluminal coronary angioplasty guidewire-induced coronary artery dissection without balloon inflation.

A case of arterial dissection of the right coronary artery secondary to angioplasty guidewire manipulation is presented. No balloon inflation was performed. The histologic appearance of the involved arterial segment was similar to that found in the left anterior descending coronary artery, which had undergone successful balloon dilatation. Both arteries demonstrated medial disruption and fibrointimal proliferation. The pathologic features of angioplasty-induced vascular injury may occur with or without balloon inflation.

Coronary angioplasty following cardiac transplantation: a case report and review of the literature.

A 23-year-old man underwent successful percutaneous transluminal coronary angioplasty of a severe stenosis of the left anterior descending artery 25 months after orthotopic heart transplantation. Four months later restenosis of the same lesion was treated by repeat PTCA. Angiography 11 months later showed no restenosis. In selected cases, PTCA may be useful in treating allograft coronary disease.

Laser angioplasty in miniature swine: advantages of a modified fiber tip delivery system.

Laser angioplasty using a spherical lensed fiber-tip laser delivery catheter and a 200 mum bare silica fiber tip was performed in occluded atherosclerotic iliac arteries of miniature swine. Group I consisted of 8 animals with 11 totally occluded arteries in which the bare silica fiber was used. Group II included 22 animals with occlusive lesions in 41 arteries in which the silica lens tip was used. In vivo laser angioplasty was performed in both groups using an argon ion laser delivering 2 to 3 watts of power in 1 to 5 second intervals. Successful recanalization occurred in 7/11 (64%) in group I arteries and 35/41 (85%) in group II arteries. Vascular perforation occurred in 36% (4/11) in group I compared to 10% (4/41) in group II (P less than 0.05). Mechanical perforation due to the bare fiber alone accounted for 50% of the perforations in group I and did not occur with the silica lens-tip device (group II). We conclude that the atraumatic lensed fiber is more effective in recanalizing occlusive lesions and is a safer delivery system than the bare silica fiber.

Tolerance of normal aorta to oversized dual balloon valvuloplasty. Observations in a swine model: technical note.

The damage threshold during aortic valvuloplasty was determined in 12 normal swine subjected to inflation of oversized dual balloons. Catheters with combined balloon diameters of 1.2-2.0 times the aortic annulus were selected. Following completion of the procedure, the animals were sacrificed and examined for pathology. With combined balloon diameters less than or equal to 1.7 times the aortic annulus, there was no gross or microscopic damage. In animals with combined diameters equal to 2 times the aortic annulus, there was rupture of the aorta. This data provides further basis for the selection of catheter sizes in dual balloon aortic valvuloplasty.

New passive perfusion PTCA catheter.

Percutaneous coronary angioplasty with a new passive perfusion balloon catheter was compared to a standard angioplasty balloon catheter during prolonged balloon inflations in miniature swine. Inflations with the passive perfusion balloon were alternated with a standard balloon with the initial balloon chosen randomly in 24 coronary arteries. End-points for terminating the balloon inflation were the appearance of 2 mm of ST segment deviation from baseline on the electrocardiogram, the occurrence of ventricular fibrillation, or 30 min of balloon inflation. During balloon inflation contrast injections were performed through the guiding catheter and flow distal to the balloon was graded 0-3 using the TIMI scale. The average (+/- SD) inflation time for the standard balloon was 3.1 +/- 2.2 minutes and for the perfusion balloon was 27.2 +/- 4.8 min (P less than 0.001). Electrocardiographic evidence of 2 mm of ST segment deviation from baseline was seen during 11/13 inflations with the standard balloon and in 3/11 balloon inflations with the perfusion balloon. Ventricular fibrillation occurred during 2/13 of the standard balloon inflations and in none during passive balloon inflations. Distal contrast flow during passive balloon inflations averaged 2.7 +/- 0.5 (TIMI scale 0-3) and was absent during inflations with the standard balloon. The perfusion balloon allowed prolonged inflations with excellent distal flow when compared to the standard balloon.(ABSTRACT TRUNCATED AT 250 WORDS)

Repeat balloon aortic valvuloplasty for aortic valve restenosis.

Effective balloon aortic valvuloplasty (BAV) is limited restenosis. After aortic valve restenosis six patients underwent repeat BAV. In spite of the use of larger balloons there was a trend toward a less satisfactory result after repeat BAV (0.98 +/- .26 cm2 vs. 1.2 +/- .26 cm2), which did not reach statistical significance, P = .14. Mortality of the patients at 6 months was 50%. Repeat BAV may be less efficacious than the original procedure.