RT: Case of the swollen Leg

1. RT: Case of the swollen Leg Cimi Achiam MD, DTMH, FRCPC

2. First visit: Sept 14, 2011 • 12:25: • 50 yr male cc: L leg swelling • 6 days of L leg swelling • Transient SOBOE w/ mildly pleuritic chest pain yesterday, but completely resolved on presentation • PMHx: • L DVT Jan 2011 • Precipitated by flight to Hawaii • Tx w/ 6/12 of Warfarin D/C in mid June • No meds currently • Family Hx: nil

3. Visit 1 • O/E: T37.2 HR 70 BP 145/78 RR20 Sat 96% RA • Chest: GAEBL, clear • CVS: S1S2 N, no murmur • Abdo: Soft NT, not distended • Neuro: Normal • L Leg: proximal swelling

4. Vist 1 Investigations • 6 Pack: - • D dimer: 646 • Troponin: -

5. Visit 1: Imaging • CTPA: • no PE, mildly prominent R hilar node of uncertain clinical significance • CT Abdo/Pelvis: • No large pelvic mass causing obstruction of veins • No acute intra-abdominal abnormality • Questionable narrowing of the left common iliac vein at the level of the overlying right common illiac artery ? May-Thurner syndrome. • Recommend Interventional Radiology consult. If there is still significant clinical concern, an MRV could be attempted or a CTV could be reattempted with a longer delay between contrast and imaging • Doppler US: • - DVT, deep venous system widely patent • No residual thrombus identified • Normal waveforms, phasicity, augmentation, and compression were obtained

6. Visit 1 • Given high clinical concern for DVT, case was discussed with radiologist and plan was made for MR venogram next day • Pt was tx in the mean time with Enoxaparin 1.5mg/kg SC

7. Visit 2: Sept 16, 2011 • 13:42: Return for MRI results • Patient’s leg re-examined: Pt looks well, no pedal swelling, good circulation to L foot • MR Venogram of Pelvis & Thighs: • Negative MR venogram with no evidence of DVT in the pelvis and LE to just above the knees • Pt instructed to return on an as needed basis

8. Visit 3: Sept 20, 2011 • Patient represented with progressive swelling of his L leg, non- painful, no paraesthesias. No CP or SOB currently or since last evaluation • O/E: • Abdomen: Soft NT, no masses or inguinal lymphadenopathy • LE: non-pitting edema from foot to mid thigh, no erythema, normal pedal pulses and motor exam

9. Visit 3 • Given multiple investigations on previous visits case was discussed with radiology • Repeat Doppler U/S planned • Doppler U/S report: • Occlusive thrombus seen within the left external iliac vein • Non-occlusive thrombus within one branch of both of the duplicated superficial femoral, and popliteal veins • ? May Thurner’s syndrome

10. Visit 3 • On suggestion of radiology, interventional radiology consulted re: possibility of thrombolysis/stenting • Was informed would have to consult vascular surgery and that they would consult IR if required • Vascular surgery consult • Pt was admitted and anticoagulated with IV heparin protocol • Sept 21/11: • Pt underwent thrombolysis & stenting of his left iliac vein • Pt advised to restart IV heparin and continue coumadinx 6 mo minimum

11. Pathophysiology of May Thurner Syndrome

12. Virchow’s Triad

13. Anatomy

14. May Thurner Syndrome • Most commonly seen in women between 20-50yrs • Episodes of DVT may be recurrent and/or poorly responsive to treatment with anticoagulation alone • May require: • Catheter-directed thrombolysis • Venous angioplasty and/or intravascular stenting • Visualization of a clot this high in the pelvis may be difficult to detect using ultrasound of LE • If DVT is strongly suspected, further testing should be performed

15. Diagnosis of Suspected DVT of LE • Only a minority of patients (17 and 32 % in two large series) actually have the disease • Accurate diagnosis is essential • Potential risk of fatal PE in untreated proximal LE DVTs • Potential risk of fatal bleeding due to anticoagulating a patient who does not have a DVT Birdwell BG, et al. Ann Intern Med 1998; 128:1-5 Huisman MV, et alNEngl J Med 1986; 314:823

16. Diagnosis of Suspected LE DVT • Pre-test probability: • Modified Well’s Score • Imaging: • “Doppler” Compression U/S • Abnormal compressibility of the vein • Abnormal Doppler color flow • The presence of an echogenic band • Abnormal change in diameter during valsalva maneuver • Non-compressibility is 95% Sens & Spec for a proximal DVT

17. Diagnosis of Suspected LE DVTs

18. Diagnostic Imaging Modalities: Beyond U/S • Contrast Venography • Non-invasive Tests: • Impedance Plethysmography • Sensitivity 91%; Specificity 96 % • MRI Venography • Sens 100%; Spec 96% • CT Venography

19. At RCH: High suspicion & - Doppler U/S • Options: • Order D-dimer: if positive bring patient back for repeat U/S in 5-7 days • Order more imaging: • CT Venogram • May be best option to rule out causes of pelvis compression ie mass and to assess iliac vessels • MR Venogram • Repeat U/S in 1 week without D-dimer

20. Management of DVTs: Beyond anticoagulation • Thrombolytics • Surgical thrombectomy • Percutaneous mechanical thrombectomy • Potential indications: • Hemodynamically unstable PE • Massive iliofemoral thrombosis • May Thurner syndrome

21. Thrombolytics • May result in more rapid and complete lysis of LE DVT & less post-thrombotic syndrome • However, seldom used because: • Clinical relevance of achieving earlier relief of venous obstruction is uncertain • Increased risk of major bleeding • Low risk of death and early recurrence if anticoagulants are started promptly at an appropriate dose • Increased risk of catastrophic bleeding may not be worth preventing post-thrombotic syndrome

22. Thrombolytics • Indications: • Massive proximal LE or iliofemoral thrombosis PLUS • Severe symptomatic swelling or • Limb-threatening ischemia (phlegmasiaceruleadolens)

23. Take Home points • In patients with recurrent left sided DVT consider May Thurner syndrome • In patients with a high probability of DVT a single negative U/S study may be insufficient • Repeat the U/S in 5-7 days or • Consider adding a D-dimer at the time of the initial workup or • Consider other imaging modalities ie CT venogram