Chapter 148 - Acute LE DVT surgical and interventional treatment

Question 1

Causes of post-thrombotic syndrome mechanism

Answer 1

1) venous hypertension due to a) valve reflux b) luminal obstruction

Question 2

Strongest predictor of post thrombotic syndrome

Answer 2

Iliofemoral DVT 40% venous claudication 15% venous ulceration 5 year follow up

Question 3

Venous hypertension definition

Answer 3

elevated venous pressure during exercise

Question 4

Scandinavian study on iliofemoral dvt anticoag vs thrombectomy and AVF

Answer 4

thrombectomy + AVF improves iliac vein patency, lower venous pressure, less edema and less PTS

Question 5

RCT on CDT for iliofemoral DVT existing and upcoming

Answer 5

1) Elsharawy study 2) CaVenT trial 3) ATTRACT trial 4) Dutch CAVA Trial

Question 6

Elsharawy trial key points

Answer 6

1) AC vs CDT 2) CDT improve venous patency, reduced valve incompetence Limitation: no PTS or QOL measures No use of Villalta score or VCSS

Question 7

CaVenT trial key points

Answer 7

1) 209 patients 2) primary endpoint: venous patency at 6 months; PTS at 2 years 3) CDT: UniFuse (AngioDynamics) with alteplase 0.01mg/kg/hr for ~ 24 hr 4) clot resolution 82% 5) CDT improves venous patency and less PTS 6) PTS absolute risk reduction 14.4% for CDT 7) major bleeding 3.3%

Question 8

Key limitation of CaVenT trial

Answer 8

45% of CDT and 36% of AC had iliofemoral DVT only 60% had true iliofemoral DVT

Question 9

ATTRACT trial key points

Answer 9

1) sponsorred by NIH 2) 692 patients with symptomatic proximal DVT (iliofem and fempop 3) CDT vs AC 4) primary endpoint PTS 24 months (Villalta > 4) 5) measurements: Villalta, CEAP, QOL, VCSS, duplex 6) no difference in PTS at 2 years 47 vs 48% 7) bleeding higher in CDT 1.7 vs 0.3% 8) fewer patients in CDT group developed moderate/severe PTS (Villalta > 9)

Question 10

Criticism of ATTRACT

Answer 10

Stratification of iliofemoral DVT not done

Question 11

Half life of plasmin in systemic circulation

Answer 11

Fraction of a second

Question 12

Success of CDT in acute DVT

Answer 12

75-90%

Question 13

Bleeding complication in CDT for acute DVT

Answer 13

5-11%

Question 14

Action of TPA

Answer 14

Covert glu-plasminogen to lys-plasminogen –> more binding sites for plasminogen activator –> increase production of plasmin

Question 15

National venous registry on CDT for acute IFDVT

Answer 15

1) improved thrombosis free survival 2) improved valve function 3) improved quality of life

Question 16

Mechanical thrombectomy endovascular success

Answer 16

26% thrombus removal 82% if with chemical Bleeding complication 14%

Question 17

Benenfit of ultrasound-accelerated thrombolysis

Answer 17

unclear

Question 18

Isolated segmental phamacomechanical thrombolysis key points

Answer 18

1) two balloons to exclude segment of interest 2) spiral catheter to mechanically disrupt and aspirate 3) improved success, reduced treatment time and tpa dose

Question 19

endovascular aspiration thrombectomy key points

Answer 19

1) need IVC filter 2) large sheath suction on way out 3) recurrence 11%

Question 20

Open venous thrombectomy overview

Answer 20

BOX 148.1

Question 21

Open venous thrombectomy step by step for infrainguinal

Answer 21

1) longitudinal inguinal incision 2) longitudinal venotomy on CFV 3) squeeze leg and dorsiflex foot to extrude clot 4) cut down to distal PT vein 5) #3 fogarty from PT vein to CFV 6) Silastic stem of IV catheter 12-14 gauge slid on balloon 7) second #4 fogarty balloon placed in other end 8) pressure applied to both balloon 9) pass balloon down the other way 10) hydraulic pressure flush the vein 11) fill with tpa and allow to sit 12) ligate FV if unsuccessful ensuring PV stays open 13) leave catheter in PT vein and ligate distally 14) leave suture ligation loose on PT vein to ligate after catheter removal

Question 22

Key points for open thrombectomy of iliofemoral segment

Answer 22

1) Number 8 or 10 venous thrombectomy balloon 2) start by placing in iliac only before going higher 3) contrast in balloon under fluoro for visualization

Question 23

Techniques to prevent clot embolizing during iliofemoral thrombectomy

Answer 23

1) contralateral balloon protection 2) IVC filter 3) PEEP

Question 24

Size of iliac vein stent

Answer 24

12 mm or larger

Question 25

AVF creation after venous thrombectomy

Answer 25

1) use end or branch of GSV 2) limit anastomosis to 3.5-4 mm 3) no increase in femoral venous pressure should occur

Question 26

Post-surgical thrombectomy care

Answer 26

1) 30-40 mmHg below knee compression 2) heparin infusion transition to AC 1 year 3) IPC until mobilizing 4) remove IVC if used

Question 27

Algorithm for iliofemoral DVT

Answer 27

FIGURE 148.8

Question 28

Patients to be considered for thrombus removal rather than just simple AC

Answer 28

1) FV occlusion 2) popliteal occlusion with adjoining proximal tibial veins

Question 29

Family testing in patients presenting with spontaneous extensive DVT

Answer 29

first degree relative females of child-bearing age for 1) Factor V Leiden 2) Prothrombin 20210 mutation 3) antithrombin III

Question 30

AHA on IFDVT

Answer 30

CDT first line for IFDVT to prevent PTS in pt with low bleeding complication Surgical thrombectomy by experienced surgeons can be done Transfer to center with CDT is appropriate Stent placement for residual disease is reasonable AC should be same as those that did not get CDT

Question 31

SVS guideline on DVT

Answer 31

Early thrombus removal for 1) ambulatory patients 2) good functional capacity 3) first episode of IFDVT 4) less than 14 day duration 5) if limb is threatened 6) pharmacomechnical if possible 7) surgical thrombectomy if CDT contraindicated