IS DUPLEX VENOUS SURVEILLANCE WORTHWHILE AFTER ARTHROPLASTY

Deep venous thrombosis (DVT) complicates 60% of knee and 80% of hip ar throplasties performed without prophylactic therapy. Routine postopera tive duplex ultrasound surveillance has been proposed for the detectio n of venous thrombosis following arthroplasty. In order to determine w hether surveillance represents an effective strategy to detect postope rative DVT when prophylaxis is used, surveillance duplex exams obtaine d after primary or revision hip or knee arthroplasty were analyzed usi ng decision analysis techniques. DVT was suspected clinically after 95 of 738 (13%) arthroplasties, with no symptoms suggestive of DVT after the remaining 643 procedures. Surveillance duplex scans were performe d within 2 weeks of 371 procedures, while no surveillance studies were performed after the remaining 272 procedures. In these asymptomatic p atients only 2 (0.5%) surveillance duplex studies were positive for DV T. In contrast, 4 of 37 (11%) duplex exams and 5 of 62 (8%) contrast p hlebograms performed among symptomatic patients were positive for DVT. The overall incidence of DVT after arthroplasty in the entire populat ion was 1.4% (10/738) with no pulmonary emboli. Patient follow-up aver aged 162 +/- 285 days. Using the 1995 Medicare reimbursement of $163 f or venous duplex, the incremental cost was $35,000 to detect 1 additio nal unsuspected DVT and $110,000 per additional quality-adjusted life- year gained. The low incidence of clinically significant DVT and pulmo nary emboli with current prophylaxis does not justify an aggressive sc reening program. Decision analysis suggests that a greater incidence o f DVT is required for screening to be worthwhile. (C) 1997 Academic Pr ess.