Biomedical subjects
Publications and source records attributed to M F Meyerovitz.
Extensive arterial dissection producing significant arterial obstruction or occlusion after technically uncomplicated percutaneous transluminal angioplasty in three patients is described. Despite the initially ominous arteriographic appearance, short-term (4-8 months) follow-up demonstrated complete resolution without surgical intervention. A trial of conservative management is recommended for this complication.
Percutaneous transluminal coronary angioplasty (PTCA) has revolutionized the treatment of patients with coronary disease. As many as 25 per cent of those requiring myocardial revascularization can now undergo PTCA instead of bypass surgery. This article reviews PTCA techniques, clinical results, case selection, complications, recent advances in equipment design, restenosis rate, use in acute myocardial infarction, and PTCA of coronary bypass grafts.
Three children with typhilitis complicating acute leukemia and presenting with severe intestinal hemorrhage are described. The arteriographic findings were hypervascularity of the cecum with intense mucosal staining, opacification of superficial ulcers, and arteriovenous shunting into dilated mesenteric veins. The three children were managed successfully with medical, surgical, and embolic therapies, respectively.
Twenty-seven children aged 1 day to 16 years studied arteriographically for acute or chronic gastrointestinal bleeding were reviewed. Children with known esophageal varices and portal hypertension were excluded. Final diagnoses were made in 25 patients by means of surgery, endoscopy, biopsy, laboratory data, and clinical follow-up. Of these 25 cases, arteriography gave a correct diagnosis in 64% and was falsely negative in 36%. In acute gastrointestinal bleeding, arteriographic diagnosis was correct in 71% and falsely negative in 29%. In chronic or recurrent gastrointestinal bleeding, arteriographic diagnosis was correct in 55% and falsely negative in 45%. The common causes of bleeding in this study were gastric and duodenal ulcers, gastritis, vascular malformations, and typhlitis. Transcatheter therapy was attempted in six acute bleeders, with success in three (50%).
PURPOSE: To compare the efficacy of surgery versus pulse-spray thrombolysis and angioplasty in patients with recurrent thrombosis of polytetrafluoroethylene (PTFE) dialysis access grafts. METHODS: We analyzed 96 consecutive interventions for thrombosed PTFE dialysis access grafts in 18 patients. Primary patency after thrombolysis and angioplasty (n = 25) was compared with primary patency following thrombectomy alone (n = 50) or thrombectomy followed by graft revision (n = 21) using life-table analysis. A Cox proportional hazards model that accounted for graft age and number of previous interventions was used to generate the relative risk for recurrent occlusion following therapy. RESULTS: Life-table analysis showed that patency after thrombolysis and angioplasty was greater than that following thrombectomy alone (p = 0.02). After accounting for the age of the graft and the number of previous interventions (average six per patient), the relative risk for recurrent occlusion [3.0; 95% confidence intervals (CI): 1.5, 6.4] was greater for thrombectomy alone than for thrombolysis/angioplasty [0.6; CI = 0.3, 1.3]. The relative risks of repeat occlusion following thrombolysis/angioplasty [0.6; CI = 0.3, 1.3] and thrombectomy/surgical revision [1.0; CI = 0.5, 1.7] were similar. CONCLUSION: Outcome data from our retrospective study on recurrent thrombosis of PTFE dialysis access grafts suggest that thrombolysis/angioplasty is superior to thrombectomy alone, and equivalent to thrombectomy/surgical revision.
PURPOSE: To evaluate whether thrombolytic therapy followed by angioplasty has any added benefit compared with angioplasty alone for the treatment of chronic peripheral arterial occlusions. PATIENTS AND METHODS: Twenty patients with claudication or limb-threatening ischemia of at least 3 weeks duration due to iliac or femoropopliteal artery occlusions were randomized either to thrombolytic therapy with recombinant tissue-type plasminogen activator for up to 4 hours (n = 11) followed by angioplasty or to angioplasty alone (n = 9). Clinical follow-up was obtained for 1 year. RESULTS: Life-table analysis revealed a significant improvement in the cumulative primary patency rate for patients with claudication treated initially with thrombolysis followed by angioplasty (n = 7; 86% at 6 months; 51% at 1 year) compared with angioplasty alone (n = 9; 11% at 6 months and 1 year) (P < .02). All four patients with limb-threatening ischemia were randomized to thrombolytic therapy, and none exhibited continued patency at 1 year. The most common complication in the thrombolysis group was peripheral embolization; three of these four patients were among those who had limb-threatening ischemia as the indication for entry into this study. There was no increased incidence of bleeding with thrombolytic therapy. CONCLUSIONS: A short course of thrombolytic therapy prior to angioplasty appears to improve the 1-year patency rate for claudication due to iliac or femoropopliteal occlusions. However, patients with limb-threatening ischemia have a high prevalence of peripheral embolization and dismal patency rates with this form of therapy. A larger scale study is necessary to confirm these findings.
Fibrinolytic therapy has become an accepted treatment modality for recent peripheral arterial and bypass graft occlusions and, in some cases, for chronic arterial occlusions. Streptokinase, urokinase, and tissue plasminogen activator have all been used for intraarterial infusion with varying protocols and results. This review focuses on dosing variables and clinical results for the various thrombolytic agents in peripheral arterial and bypass graft occlusions. Also discussed are new thrombolytic agents and the effects of concomitant use of other drugs as part of the treatment regimen.
To estimate the patency results of percutaneous transluminal angioplasty and bypass surgery in the treatment of femoropopliteal arterial disease, a Medlars search of the English-language medical literature was performed. Inclusion required that studies 1) report original data, 2) report patency with a life table or Kaplan-Meier analysis with the number at risk or standard errors, 3) define patency as hemodynamic improvement, 4) report the distribution of covariates, and 5) not duplicate other published material. Using a method based on the proportional-hazards model and the actuarial life-table approach, the results were adjusted for differences in case-mix of the study populations and patency was predicted for subgroups at various levels of risk for failure. The unadjusted pooled life tables yielded five-year patencies of 45% (+/- 2%) for angioplasty, 73% (+/- 2%) for bypass surgery using a vein graft, and 49% (+/- 3%) for bypass surgery using a polytetrafluoroethylene graft. Adjusted five-year primary patencies after angioplasty varied from 12% to 68%, the best results being for patients with claudication and stenotic lesions. Adjusted five-year primary patencies after surgery varied from 33% to 80%, the best results being for saphenous vein bypass performed for claudication. The authors conclude that pooling life-table data without adjustment for covariates can be misleading. Indication, lesion type, vein graft availability, and site of the distal graft anastomosis need to be considered in predicting patency results of revascularization for femoropopliteal arterial disease.
To study the appearance of the segmental pulmonary anatomy on single photon emission computed tomography (SPECT), 300 microCi of 99mTc-MAA was injected into one segmental pulmonary artery in patients who had elective cardiac catheterization for coronary artery disease and who had no pulmonary disease. Eighteen patients were enrolled in order to show the appearance of all pulmonary segments (10 in the right lung and 8 in the left lung). Planar and SPECT imaging were performed before and after peripheral intravenous injection of 3 mCi of 99mTc-MAA. Radioactivity in the segment was subtracted from that in the whole lung to show segmental perfusion defects on planar and SPECT whole lung images. Knowledge of the tomographic appearance of the pulmonary segments should make it easier to identify these segments on other imaging modalities that utilize sectional reconstruction, such as computed tomography and magnetic resonance imaging. This knowledge may also increase the specificity of pulmonary SPECT for the diagnosis of pulmonary emboli.
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