Andrew M. Keenan

Aspirin and warfarin for thromboembolic disease after total joint arthroplasty

This study compares the benefits of aspirin and warfarin prophylactic agents for patients with thromboembolic disease after total joint arthroplasty. It is a prospective randomized study of 388 patients having total hip or total knee surgery. All consecutive patients having total hip or total knee surgery were entered into this study and evaluated with preoperative and postoperative ventilation perfusion scans and a postoperative venogram. The aspirin and warfarin treatment groups were compared by size and location of venographically revealed clots and changes in ventilation perfusion scans. The results showed that there was no difference in the size or location of deep venous thrombosis in the aspirin or warfarin treatment groups. The venogram was negative in 44.5% of patients; 28.8% had small calf clots, 16% had large calf clots, 3.9% had popliteal clots, and 6.7% had femoral clots. Patients with total knee replacement had a 2.6 times greater incidence of calf deep venous thrombosis than patients with total hip replacement. There was no difference between the aspirin and warfarin groups in the incidence of changes in ventilation perfusion scans (18.9%). There was no difference between the 2 groups in bleeding complications. The results suggest that aspirin and warfarin are equivalent in prophylaxis against thromboembolic disease, as determined by prevention of venographic changes or changes in ventilation perfusion scans.

Nuclear cardiology in everyday practice

Foreword F.M. Domenech-Torne, J. Soler-Soler. Preface P. Ell. Introduction J. Candell-Riera, D. Ortega-Alcalde. 1. Physicochemical and technical fundamentals P. Galofre-Mora. 2. Image processing D. Ortega-Alcalde. 3. Stress testing J. Candell-Riera. 4. Myocardial perfusion studies D. Ortega-Alcalde. 5. Methods for quantifying myocardial perfusion J. Castell-Conesa. 6. Studies of myocardial damage and viability M. Fraile. 7. First-pass radionuclide ventriculography S. Aguade-Bruix. 8. Gated blood-pool radionuclide ventriculography D. Ortega-Alcalde. 9. Ventricular volume measurement J. Castell-Conesa. 10. Parametric images and Fouriers analysis D. Ortega-Alcalde. 11. Diagnosis of coronary artery disease J. Candell-Riera. 12. Prognostic evaluation and follow-up of chronic coronary artery disease J. Candell-Riera. 13. Diagnosis of acute myocardial infarction J. Cortadellas-Angel. 14. Prognostic evaluation after acute myocardial infarction A. Rius-Davi. 15. Congenital heart disease E. Galve. 16. Valvular heart disease M.P. Tornos-Mas. 17. Cardiomyopathies J. Candell-Riera. 18. Methods for diagnostic evaluation J. Rossello-Urgell. 19. The probability of a correct diagnosis M. Olona-Cabases. 20. Uses of multiple logistic regression J. Vague-Rafart. 21. Cost analysis and decision trees B.Bermejo-Fraile. Index.

An evaluation of preoperative and postoperative ventilation and perfusion lung scintigraphy in the screening for pulmonary embolism after elective orthopedic surgery

One hundred two patients undergoing elective knee or hip arthroplasty were studied with radionuclide ventilation scans (V) and perfusion scans (Q) preoperatively (preop) and postoperatively (postop) to assess their relative value in the diagnosis of asymptomatic pulmonary embolism (PE) after orthopedic surgery. Postop Q were read in combination with preop V and Q and postop V using prospective investigation of pulmonary embolism diagnosis (PIOPED) criteria. Of 25 postop Q interpreted as either high or intermediate probability for PE, preop Q were judged useful in 96%; the postop V were useful in 78%; and the preop V were not helpful in any of the cases. Of 63 postop Q interpreted as low probability, preop Q were useful in 74%; the postop V were useful in only 33%; and the preop V were useful in only one case. When postop Q were read as normal (14 cases), none of the three auxiliary studies were found to be useful. Overall, postop V were more helpful than preop Q in only 2%, and preop V contributed significantly in only 1%. This experience suggests that preop Q alone is the most useful adjunct to the postop Q in the postoperative evaluation for PE. The authors conclude that to screen for asymptomatic PE after elective orthopedic surgery, preop Q should be performed in all cases, preop V are not necessary, and postop V need be performed only if a baseline preop Q is not available.