Rule in DVT
Introduction Background Evidence System of examination Diagnoses & Variants Final actions Limitation of the examination
BACKGROUND
Common presentation Influence initial management NICE Guidelines
EVIDENCE
EXAMINATION, DIAGNOSIS & LIMITATION
Rule-In DVT Minimum Equipment Ultrasound machine B-mode ultrasound system Regularly safety checked and serviced Probe Frequencies of 3MHz and greater High frequency = better resolution = use for small legs Linear (small legs) and curvilinear (bigger legs) transducers should be available
Anatomy - CFV CFA CFA SFJ DFA CFV DFA CFV SFJ SFA LSV SFA SFV LSV SFV
Anatomy - SFV CFA DFA CFV SFJ LSV SFA SFV
Anatomy - PV SSV PA PV PV PA LSV ATV SSV PTV Per. V LSV
Rule-In DVT Pre-scanning preparation Introduction Set up machine Confirm patient s identity e.g. full name and date of birth Explanation to patient (if possible) Why? Exam process Expected duration Verbal consent Expose exam area groin to below knee Positioning Supine position Head tilt if possible (encourages leg vein distension) Hip: externally rotated Knee: slight flexion
First, Find Mickey Mouse Left Leg
Mickey Mouse Sign LSV SFV CFA LSV SFV CFA SFJ SFJ Left Leg
Evidence for Mickey Mouse Sign Duplex Ultrasound Investigation of the Veins in Chronic Venous Disease of the Lower Limbs UIP Consensus Document. Part I. Basic Principles P. Coleridge-Smith, N. Labropoulos, H. Partsch, K. Myers, A. Nicolaides, A. Cavezzi European Journal of Vascular and Endovascular Surgery. Volume 31, Issue 1, Pages 83-92 (January 2006) DOI: 10.1016/j.ejvs.2005.07.019 Anatomical Variation at the Sapheno-Femoral Junction Kimihiro Igari, Masayuki Hirokawa, Hidetoshi Uchiyama, Takahiro Toyofuku, Toshifumi Kudo, Masatoshi Jibiki, Nobuhisa Kurihara, Yoshinori Inoue Ann Vasc Dis Vol. 6, No. 4; 2013; pp 702 705 2013 Annals of Vascular Diseases. Online November 15, 2013 DOI:10.3400/avd.oa.13-00087 Transverse view of common femoral vein and artery in the right groin: Mickey Mouse view; CFA, common femoral artery; CFV, common femoral vein; SFJ, sapheno femoral junction (from the archive of PCS). Normal anatomy at the sapheno-femoral junction (transverse view). It is called Mickey mouse sign. GSV: great saphenous vein; CFA: common femoral artery; FV: femoral vein Ultrasound-guided central venous access Christopher P Gale, Andrew R Bodenham The British Journal of Cardiology. January 2008 Br J Cardiol 2008;15:51- Cross-sectional 4images of the right common femoral vessels just below the inguinal ligament, showing the Mickey Mouse sign. The femoral artery (FA) is depicted on the left and the femoral vein (FV) on the right. The sapheno-femoral junction (SFJ) comprises the long saphenous vein (LSV) and the FV
Anatomy Reminder - CFV CFA CFA SFJ DFA CFV DFA CFV SFJ SFA LSV SFA SFV LSV SFV
Finding Mickey Mouse To Slide Probe Up From If this is your first image...
Zone 1 CFV NO COMPRESSION COMPRESSION
Zone 2 SFV NO COMPRESSION COMPRESSION
Zone 3 PV NO COMPRESSION COMPRESSION
FAMUS: 3 point, Rule-In DVT Scanning process Find CFV/SFJ (Mickey Mouse) CFV/SFJ - Compress (Zone 1) Move probe down medial thigh to Mid SFV (compress along vessel as you move between zones) Mid SFV Compress (Zone 2) Move probe down medial thigh and posteriorly towards PV (compress along vessel as you move zones) (often cannot compress vessel as it goes posterior) Identify PV trification Just distal to popliteal fossa Move probe proximally until a single vessel (PV) appears PV Compress (Zone 3)
Colour Flow
Colour Flow
Colour Flow
Normal Variant Bifid venous system
Main diagnosis (DVT Rule IN) Zone 1
Main diagnosis (DVT Rule IN) Zone 2
Main diagnosis (DVT Rule IN) Zone 2
Main diagnosis (DVT Rule IN) Zone 2
Main diagnosis (DVT Rule IN) Zone 3
Other pathology of significance SFJ Incompetence
Other pathology of significance Oedema
Other pathology of significance Oedema
Other pathology of significance Lymph nodes
Other pathology of significance Lymph nodes
Other pathology of significance Bakers cyst
Other pathology of significance Bakers cyst (?Ruptured)
Other pathology of significance Haematoma
Other pathology of significance Phlebitis
Other pathology of significance Phlebitis
Other pathology of significance Aneurysm
Other pathology of significance Aneurysm
Final 3 Actions Store ALL images Ensure good clinical governance Formally Report ALL Scans Ideal Local PACS system Minimum Reporting Template secured in patients notes Act on information obtained Incorporate scan information into effective management plan Refer for departmental scan as needed
Limitation of Rule-In study Compared to Society of Vascular Technology (SVT) DVT Professional Performance Guidelines of October 2012 (Our Standard) FAMUS scans use 1 (main thrombus detection tool) of the 3 DVT assessment tools SVT Guidelines suggest B-mode should be used to image the vein and its contents; using compression of the vein in the transverse plane Spectral Doppler should be used to determine direction of flow and detect abnormal flow patterns Colour Doppler maybe used to detect thrombus as an aid to the B-mode procedure; it is an essential requirement for the assessment of the abdominal veins. Hence, FAMUS Scans cannot formally rule-out DVT Provides good sensitivity for rule-in DVT detection
QUESTIONS?