Contribution of positron emission tomography in pleural disease.

INTRODUCTION: Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. BACKGROUND: PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumour in metastatic pleurisy and in monitoring chronic or recurrent pleural pathologies. CONCLUSIONS: PET should therefore be considered as a useful tool in the diagnosis of liquid or solid pleural pathologies.

[The contribution of positron emission tomography in pleural disease]. / Apport de l'imagerie par tomographie à émission de positons dans la pathologie pleurale. Intérêt de la TEP en pathologie pleurale.

INTRODUCTION: Positron emission tomography (PET) has a clear role in oncology, particularly in thoracic disease. In the light of our experience and a revue of the literature we define precisely the role of metabolic imaging in the diagnosis of pleural pathology. BACKGROUND: In particular PET allows characterisation of malignant pleural disease and provides prognostic information in mesothelioma. Metabolic imaging provides clinical information for the staging of pulmonary cancer, in the search for a primary tumour in metastatic pleurisy and also in the follow up of chronic or recurrent pleural pathology. CONCLUSIONS: It is justified, therefore, that PET joins the diagnostic armamentarium of pleural pathology, solid or liquid.

99mTc-MIBI (RP-30) to define the extent of myocardial ischemia and evaluate ventricular function.

99mTc-MIBI, a new myocardial perfusion agent, is a technetium labeled isonitrile derivative. We have taken advantage of the physical characteristics of 99mTc to combine at rest, post infarction, ventricular function studies with analysis of perfusion. We have studied at rest and at stress, 22 patients with coronary artery disease selected on the basis of an abnormal coronary angiogram or on the basis of a positive exercise ECG stress test for symptomatic angina. We have also studied, at rest only, 20 patients with a previous myocardial infarction. A comparative thallium planar scintigraphy was obtained for all patients. The sensitivity of 99mTc-MIBI scintigraphy for detecting individual vessel lesions at stress was 88% as compared with 83% for 201Tl. Sensitivity was higher in patients with previous myocardial infarction (93% for the 2 isotopes) than in patients without (85% for 99mTc-MIBI versus 81% for 201Tl). Segmental myocardial correspondence between 99mTc-MIBI and 201Tl was very close (92%). The overall sensitivity for the detection of acute myocardial infarction reached respectively 91% for 99mTc MIBI and 87% for 201Tl. The specificity in the regions corresponding to arteries not involved was excellent for both tracers as we did not observe any false positive result. This is important information but it does not correspond to the specificity to detect coronary artery disease in the overall patient population. The correlation between first pass left ventricular ejection fraction obtained with 99mTc-MIBI and equilibrium left ventricular ejection fraction obtained with 99mTc red cells was excellent (r = 0.96). It was not as good but was still satisfactory for the right ventricle (r = 0.75).(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of thromboendarterectomy in association with coronary artery bypass grafting.

Thromboendarterectomy is sometimes performed in association with coronary artery bypass graft surgery (CABG). Right coronary arteries and severely narrowed coronary arteries mainly undergo thromboendarterectomy, but perioperative acute myocardial infarctions (AMI) are possible complications. One hundred seventy-six consecutive patients with rest and stress thallium-201 scintigraphy and angiography were studied before and after surgery. To compare patients with and without thromboendarterectomy, 48 patients who had undergone thromboendarterectomy and whose characteristics matched closely those of patients who had not were selected. Twenty patients had previous AMI before CABG in each group. Analysis accounted for the severity of vessel lesion (complete or incomplete) and for the patency of the graft and of the native coronary artery. In these 96 patients, graft patency was lower than in the overall group and similar among patients with and without thromboendarterectomy among the 56 patients without previous AMI. In patients with previous AMI and thromboendarterectomy, however, reperfusion was achieved more often through the native vessel than through the graft. New AMI or residual ischemia occurred in 32% of the areas undergoing thromboendarterectomy and in only 5% of the standard grafts (p less than 0.001). Best results were obtained in patients with incomplete occlusion after AMI. Patients without previous AMI had worse results. Thus, thromboendarterectomy can yield 64 to 75% good results in selected subgroups when CABG is otherwise impossible, but should be avoided in mildly or moderately stenotic arteries perfusing noninfarcted myocardium.

Prevention of aorta-coronary bypass graft occlusion. Beneficial effect of ticlopidine on early and late patency rates of venous coronary bypass grafts: a double-blind study.

The efficacy of coronary bypass grafting obviously being linked to graft patency, it is compulsory to look for any innovation that could improve the patency rate. Ticlopidine, an antiplatelet drug, was tested against placebo in a double-blind trial: 173 patients (475 grafts) subjected to venous coronary artery bypass grafting were randomly treated with ticlopidine (250 mg twice daily) or placebo from the second postoperative day for 12 months. Graft patency was assessed by digital angiography on days 10 (99.4% of the patients), 180 (98.2%), and 360 (91.7%). The effect of treatment on platelet aggregation and bleeding time were measured concomitantly; a clear-cut effect was demonstrated at each interval. Intention-to-treat graft-by-graft analysis shows that ticlopidine significantly reduced the graft occlusion rate on day 10 (7.1% versus 13.4%, p less than 0.05), day 180 (15.0% versus 24.0%, p less than 0.02), and day 360 (15.9% versus 26.1%, p less than 0.01). Sequential grafts to the left anterior descending coronary artery, with side-to-side anastomosis to diagonal branch(es), are less frequently occluded than individual grafts. On the contrary, grafts to endarterectomized vessels occlude more frequently. Individual patient-by-patient analysis shows that patency of all grafts at each study time, is more frequent in the ticlopidine group. The difference is significant when one considers patients without sequential or endarterectomized grafts. The difference is also present at each study time: day 10 (84.4% versus 66.7%, p less than 0.05), day 180 (74.4% versus 52.3%, p less than 0.05) and day 360 (75.0% versus 52.5%, p less than 0.05). Results are even more impressive if one excludes from analysis the four patients in the ticlopidine group in whom administration of the drug was delayed. This supports previous suggestions that early therapy is necessary. These results show that graft occlusion occurs mainly in the first 6 postoperative months. The incidence of occlusion is significantly reduced by ticlopidine therapy.