Improving follow-up of incomplete lower extremity venous duplex ultrasound examinations performed for deep and superficial vein thromboses

Objective: A lower extremity venous duplex ultrasound (LEVDUS) examination is the standard diagnostic test to evaluate patients for lower extremity deep vein thrombosis (DVT). However, some studies will be incomplete for a variety of reasons, including patient-related factors such as pain, edema, a large leg circumference, or the presence of overlying bandages or orthopedic devices. We previously reported that the frequency of obtaining a follow-up examination after an incomplete and negative (I/N) LEVDUS examination was low but that the rates of DVT found on the follow-up studies of initially I/N LEVDUS studies were similar to the rates of DVT found with initially complete LEVDUS examinations. Therefore, we recommended process improvements to increase follow-up LEVDUS studies after an I/N LEVDUS examination. In the present study, we have described the results of appending a recommendation to obtain a follow-up LEVDUS study to preliminary and final reports of I/N LEVDUS. Methods: Starting in January 2019 through December 2019, a recommendation to obtain a repeat LEVDUS examination after an I/N study was appended to the preliminary and final reports of all I/N LEVDUS examination of patients who did not, otherwise, have an indication for anticoagulation (group 2). The patients were identified on an ongoing basis through the study period and entered into an Excel database (Microsoft Corp, Redmond, Wash). Group 2 was compared with a previously reported historic control cohort of patients identified from January 2017 to December 2017 (group 1). We compared groups 1 and 2 with respect to the frequency of the repeat studies performed within 4 weeks after an I/N LEVDUS examination and the DVT rates found from the follow-up LEVDUS examinations after an I/N LEVDUS study. Results: Of the patients in groups 1 and 2, 187 and 229 had had I/N LEVDUS examinations, with 28% and 40.2% of group 1 and 2 studies having follow-up LEVDUS examinations (P < .01). Previously unidentified lower extremity thrombi were discovered in 21% of the group 2 follow-up examinations. Also, the rate of new thrombi detected was not different between groups 2 and 1 (historic controls; DVT, 14.3% vs 18.5% [P = .25]; SVT, 6.3% vs 3.3% [P = .15]). A definitive finding of either positive or negative for DVT and SVT with a complete examination in 50% of the group 2 patients with follow-up examinations. Conclusions: A recommendation to obtain a follow-up examination appended to the preliminary and final I/N LEVDUS reports was associated with an increased rate of follow-up examinations, which revealed many previously undetected DVTs and SVTs or had allowed for definitive exclusion of DVT.