low risk deep vein thrombosis (DVT)

Managing low risk clots in high risk pa1ents: A case report showing propaga0on of an unstable peroneal deep vein thrombosis to saddle pulmonary embolism during serial ultrasound scanning

Marcia Bockbrader MD PhD, Jayesh Vallabh MD, Kevin Donlon MD, MaBhew Fanous MD, David Bahner MD RDMS [email protected]

Objec0ves •  To illustrate the propagation of a low risk deep vein thrombosis (DVT) to pulmonary embolism (PE) during serial venous duplex scanning (VDS) in a high risk patient •  To discuss algorithms for DVT treatment for high risk patients

Managing low risk clots in high risk patients

Introduc0on Patients may be high risk from: •  Risk factors for developing DVT •  Risk factors for bleeding with pharmacologic DVT prophylaxis •  Risk factors for propagation of a known thrombus Managing low risk clots in high risk patients

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Recent surgery or hospitaliza0on Immobility or paresis Pregnancy or estrogen therapy Malignancy CHF or thrombophilias

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Wells Score or HAS-BLED criteria Age > 65, prior Stroke, HTN, cancer, DM Renal or liver dysfunc0on Bleeding tendency, labile INRs Anemia, thrombocytopenia Drugs (etoh, an0platelets, NSAIDs) Recent surgery, frequent falls

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Proximal loca0on Large size (>5cm long, >7mm dia) Inpa0ent status, immobility Persistent/irreversible risk factors for DVT ?? Compression from VDS ??

Problem •  Some risk factors for DVT are also risk factors for bleeding and/or DVT propagation •  Most patients in acute inpatient rehabilitation are high risk •  What are the best strategies for DVT treatment and prophylaxis for these high risk patients? Managing low risk clots in high risk patients

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Recent surgery or hospitaliza0on Immobility or paresis Pregnancy or estrogen therapy Malignancy CHF or thrombophilias

•  •  •  •  •  •  • 

Wells Score or HAS-BLED criteria Age > 65, prior Stroke, HTN, cancer, DM Renal or liver dysfunc0on Bleeding tendency, labile INRs Anemia, thrombocytopenia Drugs (etoh, an0platelets, NSAIDs) Recent surgery, frequent falls

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Proximal loca0on Large size (>5cm long, >7mm dia) Inpa0ent status, immobility Persistent/irreversible risk factors for DVT ?? Compression from VDS ??

Standard of Care •  For high risk patients with bleeding risk: •  Mechanical DVT prophylaxis with sequential compression devices (SCDs) •  IVC filter placement for treatment of proximal lower limb (high risk) DVT’s •  Surveillance with serial venous duplex scanning (VDS) instead of treatment for distal lower limb (low risk) DVT’s The presump*on is that only ~1 in 6 of calf DVT’s propagate and serial VDS is safer for the pa*ent than IVC ﬁlter placement or an*coagula*on Managing low risk clots in high risk patients

Case Descrip0on


53 year old

Case Descrip0on Our acute inpatient rehabilitation patient was HIGH RISK because of •  Recent intracranial bleed: ischemic stroke with hemorrhagic conversion •  Recent surgical intervention: craniectomy for decompression •  Relative immobility: hemiparetic (on right) from stroke But he had no DVT on VDS when admitted to rehab on post stroke day (PSD) 18 •  He received only mechanical DVT prophylaxis until PSD 22 when he was cleared to begin prophylactic dose heparin •  He developed right calf swelling and pain on PSD 24 – VDS found peroneal DVT He received standard of care: prophylactic dose heparin with plan for serial VDS •  Repeat VDS on PSD 31 showed right peroneal DVT and new partially occlusive thrombus in his right proximal femoral vein, which disappeared during scanning •  He acutely developed tachycardia, tachypnea, and O2 desaturations and had a large saddle PE on CT pulmonary angiogram Managing low risk clots in high risk patients

VDS on Poststroke Day 31

Non-compressible: Right Peroneal Vein DVT


VDS on Poststroke Day 31 Non-compressible: Right Femoral Vein DVT … Disappeared A_er scanning Contralateral limb


CT Pulmonary Angiogram

PE on post stroke day 31


Discussion •  In the early stages of DVT formation, unstable clots that are sessile with tenuous adhesion to vessel walls may be susceptible to being dislodged with pressure •  Serial VDS for surveillance of low risk (distal lower limb) DVT’s may contribute to clot embolization and progression of lower limb DVT to PE


Discussion •  Mehdipoor et al. (2016) reviewed 3626 articles published from 1960-2015 and found: •  8 case reports of of confirmed or probable clot embolization with PE after compression ultrasonography (US) of lower limb DVT’s •  Most patients reported symptoms during VDS, some with associated disappearance of previously occlusive thrombi on US •  2 cases were fatalities •  Thrombus sites included femoral and calf veins •  Clot characteristics and US techniques associated with embolization are unknown •  They conclude that clot dislodgement secondary to compression occurs more frequently than is reported Managing low risk clots in high risk patients

Proposed treatment algorithm for DVT’s in high risk pa0ents DVT found Proximal Lower Limb No contraindica0ons to an0coagula0on

Distal Lower Limb Bleeding risk high * IVC ﬁlter

No contraindica0ons to an0coagula0on

An0coagulate *Previously, algorithm recommended observation with compressive ultrasound every week for 2 weeks (or as long as DVT is unresolved) Managing low risk clots in high risk patients

Conclusions •  This case shows that conservative management of DVT's with serial VDS may not be benign in the acute stage of thrombus formation, when clots are most likely to be unstable •  Rehabilitation patients often fall into the high risk category for DVT’s due to immobility, but may also have conditions that are contraindications for anticoagulation •  In high risk patients who have low risk clots, IVC filter placement may be preferred to serial VDS to prevent the morbidity and mortality associated with PE Managing low risk clots in high risk patients

References 1. Guyatt, G., Akl, E., Crowther, M., Gutterman, D, & Schuunemann, H. (2012). Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest, 141(2). 2. Henry, J., & Satiani, B. (2014). Calf muscle venous thrombosis: A review of the clinical implications and therapy. Vascular and Endovascular Surgery, 48(5-6). 3. Mehdipoor, G., Shabestari, A., Lip, G., Bikdeli, B. (2016). Pulmonary Embolism as a Consequence of Ultrasonographic Examination of Extremities for Suspected Venous Thrombosis: A Systematic Review, Semin Thromb Hemost, Feb 2016 DOI: 10.1055/s-0036-1571336. 4. Pathansali, R. (2015). Management of post-stroke complications, (A. Bhalla & J. Birns, Eds.). London, UK: Springer International Publishing Switzerland. 5. Lip, G. (2015). Overview of the treatment of lower extremity deep vein thrombosis, UpToDate. Accessed 2/25/16. 6. Wijdicks, E. (2014). The use of thrombotic therapy in patients with an acute or prior intracerebral hemorrhage, UpToDate. Accessed 2/25/16.
