indium-oxine and Arterial-Occlusive-Diseases

The effects of a recently synthesized anti-platelet aggregation drug (E-5510) on platelet deposition in a knitted Dacron aortic graft underwent preliminary evaluation by In-111 oxime labeled platelet imaging. Seven patients undergoing aortofemoral bypass using this graft for occlusive disease were randomized into two groups: those receiving E-5510 and those receiving no medication. This agent was administered for 17 days postoperatively, and on the 14th day In-111 platelets were injected and images were acquired at 24, 48, and 72 hours. Platelet deposits in the grafts were assessed by the ratios of graft radioactivity to that of the adjacent native iliac arteries. Platelet deposition at the sites of anastomosis and deposition along the entire graft were normalized by initial deposition at 24 hours, and had significantly decreased at 72 hours in the three treated patients, while the normalized deposition increased progressively over time in the remaining four nonmedicated patients. E-5510 seems to have the potential to inhibit excessive platelet deposition on recently implanted grafts.

Topics: Aged; Aged, 80 and over; Aorta, Abdominal; Arterial Occlusive Diseases; Blood Vessel Prosthesis; Fatty Acids, Monounsaturated; Femoral Artery; Graft Occlusion, Vascular; Humans; Indium Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Aggregation; Platelet Aggregation Inhibitors; Polyethylene Terephthalates; Radionuclide Imaging

The amount and time course of platelet accumulation at angioplasty sites and influence of these platelets on restenosis after percutaneous transluminal angioplasty (PTA) in peripheral arteries were determined in 92 patients, who received either a high or low dose of aspirin. Platelet deposition was quantitated by means of dual-radiotracer scintigraphy and calculation of a platelet accumulation index (PAI). The PAI was higher (P less than .05) 4-6 hours after PTA compared with that on subsequent days. There was a trend toward greater platelet accumulation in vessels with extensive dissection. Platelet accumulation at the PTA site occurred with both doses of aspirin, with no differences between the two dosage groups. Twenty-one of 67 patients who underwent PTA in the femoropopliteal segment developed restenosis during a median follow-up of 14 months. The median PAI at 4-6 and 22-24 hours after PTA was significantly less in these 21 patients than in the 46 without restenosis. The data suggest that use of antiplatelet agents to prevent platelet deposition after PTA may not be useful for prevention of restenosis.

Topics: Angioplasty, Balloon; Arterial Occlusive Diseases; Aspirin; Blood Platelets; Constriction, Pathologic; Female; Femoral Artery; Follow-Up Studies; Humans; Iliac Artery; Indium Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Aggregation; Popliteal Artery; Recurrence; Time Factors

Fourteen patients were examined between 3 weeks and 11 years after implantation of an aortobifemoral vascular graft with 111In labelled leukocytes isolated with discontinuous gradient centrifugation. The camera acquisition was performed with a three phase technique (acquisitions at 30 min, 4 h and 24 h p.i.). The presence and extent of a graft or perigraft infection including complicating fistulas could be correctly diagnosed in six of eight patients with surgically proven infections. Leukocyte uptake index was calculated as 1.77 +/- 0.4 (30 min p.i.) and 2.4 +/- 0.7 (24 h p.i.). All infections could be diagnosed by 30 min p.i., fistulas only could be seen 24 h p.i. In two of eight patients, false positive results were observed. These patients suffered from suspected perigraft hematomas and noninfected aortic graft aneurysms. Both had a negative 30 min scan and a slight uptake in the late scans comparable to bone marrow activity. Six patients with fever of unknown origin showed true negative scans. There were no false negative scans. We conclude that only the leukocyte scan can diagnose the presence and the extent, including fistulas, of vascular graft infections. The three phase technique is recommended to localize the blood pool in the 30 min scan and to diagnose complications 24 h p.i. In cases of a negative 30 min scan and positive 4 h and 24 h scans, false positive results should be suspected. All infections have a leukocyte uptake index higher than 1.2.

Topics: Aged; Aneurysm; Aorta, Abdominal; Arterial Occlusive Diseases; Blood Vessel Prosthesis; Female; Femoral Artery; Granulocytes; Humans; Indium Radioisotopes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Postoperative Complications; Radionuclide Imaging; Surgical Wound Infection

Scintigraphy with 111indium-marked autologous platelets has been used during percutaneous transluminal dilatation of supra-aortic arterial stenoses; there were 14 successful dilatations and one attempted dilatation. The material consisted of nine stenoses of the internal carotid artery, two stenoses at the origin of the vertebral artery and four stenoses of the first part of the left subclavian artery. Deposition of thrombi could be demonstrated by scintigraphy, both before and after catheter dilatation. The value of this method for deciding on the type of treatment and for observing the course of percutaneous dilatation of cerebral vessels is discussed.

Topics: Angioplasty, Balloon; Arterial Occlusive Diseases; Blood Platelets; Carotid Artery Diseases; Humans; Indium; Methods; Organometallic Compounds; Oxyquinoline; Radioisotopes; Radionuclide Imaging; Subclavian Artery; Vertebral Artery

Intracardiac and arterial thrombi were examined by scintigraphy using In-111-oxine labeled autologous platelets. In 22 cases of myocardial infarction including six with ventricular aneurysms, four had positive findings of thrombi on imaging and detected also by echocardiography. All four had ventricular aneurysms. The so-called "moya-moya" echoes (fuzzy echoes) were demonstrated in two of these four cases. We encountered two cases with positive findings on imaging in 13 with mitral valve disease. These two had systemic embolic episodes after scintigraphic examination. "Moya-moya" echoes were detected in the left atrial cavity in four with negative findings on imaging. Positive images were obtained in two of three with acute arterial occlusive disease, and in both cases platelet deposition was observed in the proximal site of obstruction. Though thrombectomy was performed for one of these two cases, no thrombus was detected at the site of platelet deposition. After one month, re-examination revealed only negative findings in all sites in both these patients. In the six cases of aortic aneurysm, three had platelet deposition within their aneurysms, and surgery was performed for these positive cases, but one of them had no thrombus. Positive images were obtained in only one of seven patients with chronic arterial occlusive disease. Coagulation tests and platelet studies were investigated for patients with positive or negative platelet scans. Only the data of the thrombo-test showed a significant difference (97 +/- 9% vs 23 +/- 7%, p less than 0.001). Three cases of positive imaging became negative after anticoagulant therapy. We tried ECT for eight cases 24 hours after injection of In-111-oxine labeled platelets. Three cases showed clear images of thrombi, while the planar images could not detect them at an early stage. Therefore, we propose that ECT can be a useful technique for diagnosing intracardiac thrombi in early stage.

Topics: Aged; Arterial Occlusive Diseases; Blood Platelets; Child; Child, Preschool; Heart Diseases; Humans; Hydroxyquinolines; Indium; Infant; Infant, Newborn; Male; Myocardial Infarction; Organometallic Compounds; Oxyquinoline; Thrombosis; Tomography, Emission-Computed

Prosthetic graft occlusion is most frequent in the early postoperative period when the luminal surface is highly thrombogenic. It is generally believed that graft maturation ultimately results in a non-thrombogenic surface. The accumulation of 111-indium-labelled autologous platelets in Dacron aortofemoral grafts has been measured 1 week following surgery and at intervals of 6 months to 1 year. Platelets from 9 patients were labelled with 111-indium oxine and re-injected. Isotope emissions over the graft and a reference site (aortic arch) were measured daily for 8 days and gamma camera images taken on alternate days. Graft thrombogenicity was calculated as the daily rise in the graft: reference ratio of emissions. All grafts, regardless of age, accumulated platelets and were imaged by gamma camera. Mean thrombogenicity (+/- s.e.mean) 1 week after surgery was 0.21 +/- 0.04 compared with 0.08 +/- 0.03 at follow-up (P less than 0.01). The platelet survival during the early study was reduced at 6.8 +/- 0.6 days but recovered to a value of 8.6 +/- 0.8 days (P less than 0.01) at follow-up. Further grafts, 2, 5 and 9 years old, were studied and all accumulated platelets, especially near the anastomoses. Platelet accumulation on Dacron grafts does diminish with time but persists beyond the period of altered platelet survival and perhaps indefinitely.

Topics: Aorta, Thoracic; Arterial Occlusive Diseases; Blood Platelets; Blood Vessel Prosthesis; Female; Humans; Iliac Artery; Indium; Isotope Labeling; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Aggregation; Platelet Count; Polyethylene Terephthalates; Radioisotopes; Radionuclide Imaging