Duplex Ultrasonography Has Limited Utility in Detection of Postoperative DVT After Primary Total Joint Arthroplasty

Abstract

Background: Duplex ultrasound is routinely used to evaluate suspected deep venous thrombosis after total joint arthroplasty. When there is a clinical suspicion for a pulmonary embolism, a chest angiogram (chest CTA) is concomitantly obtained. Questions/Purposes: Two questions were addressed: First, for the population of patients who receive duplex ultrasound after total joint arthroplasty, what is the rate of positive results? Second, for these patients, how many of these also undergo chest CTA for clinical suspicion of pulmonary embolus and how many of these tests are positive? Furthermore, what is the correlation between duplex ultrasound results and chest CTA results? Methods: A retrospective chart review was conducted of total joint replacement patients in 2011 at a single institution. Inclusion criteria were adult patients who underwent a postoperative duplex ultrasonography for clinical suspicion of deep venous thrombosis (DVT). Demographic data, result of duplex scan, clinical indications for obtaining the duplex scan, and DVT prophylaxis used were recorded. Additionally, if a chest CTA was obtained for clinical suspicion for pulmonary embolus, results and clinical indication for obtaining the test were recorded. The rate of positive results for duplex ultrasonography and chest CTA was computed and correlated based on clinical indications. Results: Two hundred ninety-five patients underwent duplex ultrasonography of which only 0.7% were positive for a DVT. One hundred three patients underwent a chest CTA for clinical suspicion of a pulmonary embolism (PE) of which 26 revealed a pulmonary embolus, none of which had a positive duplex ultrasound. Conclusion: Postoperative duplex scans have a low rate of positive results. A substantial number of patients with negative duplex results subsequently underwent chest CTA for clinical suspicion for which a pulmonary embolus was found, presumably resulting from a DVT despite negative duplex ultrasound result. A negative duplex ultrasonography should not rule out the presence of a DVT which can embolize to the lungs and thus should not preclude further workup when clinical suspicion exists for a pulmonary embolus.

Recommendations from the ICM-VTE: General

“…To date, despite the frequent use of venography and venous duplex for diagnosis of DVT in clinical trials, routine venous duplex and venography screening following THA and TKA is not recommended by the clinical practice guidelines developed by the American Academy of Orthopaedic Surgery (AAOS) and the American College of Chest Physicians (AACP) 1230-1234 .…”

“…Both groups developed similar rates of proximal DVT by day 35 postoperatively (below 9%), questioning the utility of screening ultrasound 1232 . Furthermore, a recent retrospective single-center study found that in patients who underwent total joint arthroplasty and had a duplex ultrasound, only 0.7% of them had a DVT and none of them exhibited clinical symptoms 1234 . Shahi et al, found that the rate of in-patient DVT being diagnosed has decreased significantly during the past decade, likely due to less screening of asymptomatic patients, while the rate of PE development has remained stable 1210 .…”

“…In addition, many distal DVT developed in the postoperative period resolve even without a treatment 1236 . It is believed that DVT and PE can arise independent of each other and in hypercoagulable states, such as the postoperative period 1234,1237 . In addition, a recent systematic review of contemporary trials of anticoagulation, the importance of asymptomatic DVT detected by mandatory screening was questioned 1238 .…”

Venous thromboembolism: diagnostic advances and unaddressed challenges in management

“…Additionally, ultrasound, an imaging modality without those burdens, has high rates of missed diagnoses due to low true positive and high false negative rates [47]. In settings where ultrasound is not available, has limited use [48], or is inconclusive, secondary imaging modalities such as CT or MRI venography can provide 3D reconstructed images to estimate thrombus burden; however, standardized protocols for quantification are lacking. Pretest probability assessments such as the Wells and Caprini Scores help stratify risk and guide VTE diagnosis [49,50]; however, they are inconsistently applied and can still lead to missed diagnoses.…”